Hutt v Enig Pty Ltd - [1998] FCA 686

FEDERAL COURT OF AUSTRALIA

INTELLECTUAL PROPERTY - patents - alleged infringement of combination patent - counterclaim for revocation - applicant a registered proprietor of a patent for diffuser valve used in fluidising powdered products.

INTELLECTUAL PROPERTY - combination patent - construction of patent specification - principles to be considered by Court - purposive and common‑sense construction - what the normal person skilled in the art would determine as the meaning - whether the valve was a “controllable valve” - the location and extent of the valve face and the arcuate surface of the valve face - meaning of “overhang the valve seat”.

INTELLECTUAL PROPERTY - infringement - whether respondents’ valve infringed applicant’s patent - whether respondents’ valve controllable - whether respondents’ valve face had an arcuate surface - whether fluid escaped from the respondents’ valve at right angles to the valve member.

INTELLECTUAL PROPERTY - combination patent - validity of patent - obviousness - Court to consider the selection of the combination of integers not each separate integer- want of novelty - sufficiency of description -whether the claims were fairly based on the matter described in the complete specification - whether there was a real and reasonably clear disclosure in the body of the specification that valve was a controllable valve and the fluid escaped at right angles.

INTELLECTUAL PROPERTY - effect of Patents Act 1990 (Cth) on patents granted under Patents Act 1952 (Cth)

Patents Act 1990 (Cth): s 40(3), s 233(1), s 233(4)

Catnic Components Limited & Anor v Hill & Smith Limited [1982] RPC 183 - applied
Populin v HB Nominees Pty Ltd (1982) 41 ALR 471 - applied
Decor Corporation Pty Ltd & Anor v Dart Industries Inc (1988) 13 IPR 385 - applied
British Celanese Ltd v Courtaulds Ltd (1935) 52 RPC 171 - applied
Interact Machine Tools (NSW) Pty Ltd v Yamazaki Mazak Corporation (1993) 27 IPR 83 - applied
Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 - applied
Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 - applied
CCOM Pty Ltd v Jiejing Pty Ltd (1994) 51 FCR 260 - applied
Leonardis v Sartas No 1 Pty Ltd (1996) 67 FCR 126 - applied

JAMES JOSEPH HUTT v ENIG PTY LTD & ORS
VG 153 of 1993

GOLDBERG J
MELBOURNE
12 JUNE 1998

IN THE FEDERAL COURT OF AUSTRALIA

VICTORIA DISTRICT REGISTRY

VG 153 of 1993

BETWEEN:

JAMES JOSEPH HUTT
Applicant

AND:

ENIG PTY LTD
First Respondent

J S MELBOURNE CONTROLS PTY LTD
Second Respondent

JOHN STANLEY MELBOURNE
Third Respondent

JUDGE:

GOLDBERG J

DATE OF ORDER:

12 JUNE 1998

WHERE MADE:

MELBOURNE

THE COURT ORDERS THAT:

The application be dismissed.

The cross‑claim be dismissed.

The applicant pay the second and third respondents’ costs of and incidental to the application including reserved costs.

The second and third respondents pay the applicant’s costs of and incidental to the cross‑claim including reserved costs.

Note:Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules

IN THE FEDERAL COURT OF AUSTRALIA

VICTORIA DISTRICT REGISTRY

VG 153 of 1993

BETWEEN:

JAMES JOSEPH HUTT
Applicant

AND:

ENIG PTY LTD
First Respondent

J S MELBOURNE CONTROLS PTY LTD
Second Respondent

JOHN STANLEY MELBOURNE
Third Respondent

JUDGE:

GOLDBERG J

DATE:

12 JUNE 1998

PLACE:

MELBOURNE

REASONS FOR JUDGMENT

Introduction

The applicant is the registered proprietor of Australian Letters Patent No 582742 for an invention entitled “a diffuser valve” (“the patent”). The subject of the patent, a valve, is used in the fluidising of powdered products in hoppers, silos and packing machines. It is sold throughout the world by a company under a licence arrangement with the applicant. The relevant priority date for the patent is 30 April 1984 and the patent specification became open to public inspection on 7 November 1985. On 4 August 1989 the letters patent were sealed for a term of sixteen years from 24 April 1985. The second respondent manufactures a valve (“the respondents’ valve”) and the applicant claims that the valve infringes his patent. The second and third respondents have cross‑claimed seeking a declaration that the patent is invalid and an order that the patent be revoked. The third respondent is, and is sued as, a director of the second respondent but no independent cause of action against him was pressed at the hearing. A notice of discontinuance was filed in respect of the first respondent.

In the patent specification the problems which the invention claimed to overcome were described as follows:

“When particulate materials such as powders are stored in a hopper problems often arise because the powder tends to 'bridge' or, even in some cases pack solid, and this may be the case whether the material inside the hopper is moist or dry. When material within a hopper does bridge or pack solid if there are no mechanical facilities for correcting the condition it is necessary for the materials to be loosened manually so that predetermined flows from the hopper can be maintained.
To overcome the problem of bridging or packing it is known to provide a plurality of nozzles which are provided in strategic positions on or within a hopper and to apply high pressure air via the nozzles to the material within the hopper in an endeavour to correct the problem. Other means for overcoming the problem have included dispersing air through members which protrude into the hopper interiors however neither of the solutions to the problem have proved to be totally effective or economic.
It is an object of the present invention to provide a diffuser valve which may be effectively used in the aforesaid situations.”

Mr Lohning, the expert consulting engineer called by the applicant explained that the immediate result which the valve operates to achieve is the movement of the fluid under pressure, such as air or water, from the body of the valve via an outlet to an area external to the valve. In a typical application, such as the release of air from the valve along the internal facing of the wall of a container or hopper where the hopper contains granular material, the movement of the air into the hopper has the effect of moving or disseminating the material in a particular way. By the radial diffusion of air under pressure into the hopper, the granular material is fluidised in the sense that the grains are caused to tend to flow or run like water.

The respondents deny that there has been any infringement of the essential features of the patent. In support of their claim for invalidity they allege in their particulars of invalidity:

(a)the complete specification does not comply with s 40 of the Patents Act 1952 (Cth) (“the 1952 Act”) in that:
“(a)The complete specification does not fully describe the alleged or any invention;
(b)The claims of the complete specification do not define or sufficiently or clearly define the alleged or any invention;
(c)The said claims are neither clear nor succinct and are ambiguous and uncertain;
(d)The said claim are not fairly based on the matter described in the complete specification as lodged or as accepted.”

(b)want of novelty at the priority date;
(c)the invention was obvious and did not involve an inventive step;
(d)the invention is not an invention within the meaning of the Patents Act 1990 (Cth) (“the Act”).

The applicant’s patent was granted under the 1952 Act. Section 233(1) of the Act provides that the Act applies in relation to the patent as if it had been granted under the Act. By reason of s 233(4) objection cannot be taken to the validity of a patent granted under the 1952 Act on any ground that would not have been available against the patent under the 1952 Act. These provisions were explained in NV Philips Gloeilampenfabrieken v Mirabella International Pty Limited (1993) 44 FCR 239 by Lockhart J (Northrop J agreeing), in a passage not challenged in the High Court appeal ((1995) 183 CLR 655) at 253 ‑ 254:

“... the evident intent of s 233(4) is to ensure that the grounds of revocation under the 1990 Act ... apply as the grounds for revocation of a 1952 Act patent; but with this important qualification, namely, that the elements of each ground of revocation under the 1990 Act apply only to the extent that they replicate in substance the elements that previously constituted a ground of revocation under the 1952 Act. Hence, if a ground of revocation under the 1990 Act, omits an element which was a necessary part of a ground under the 1952 Act, the patentee has the benefit of it. On the other hand, if a ground under the 1990 Act contains an element not previously present under the 1952 Act, it cannot apply in aid of revocation of the 1952 Act patent ...”

The issues before the Court turn substantially on the proper construction of the claims which are in the following form:

“1.A controllable valve comprising a body, a valve member mounted within the body, said valve member comprising a stem mounted for reciprocation within the body and a valve head opening to and positioned at one end of the body, a fluid outlet positioned at the same end of the body including a valve seat upon which a valve face of the valve head may rest, said valve face being provided with an arcuate surface the outer peripheral extremities of which overhang the valve seat so as to direct fluid escaping from the outlet radially outwardly and at right angles to the lengthwise axis of the valve member and means communicable with said fluid outlet by which the valve may be connected fluid under pressure, the construction and arrangement being such that, in use, with the valve mounted in the wall of a container and the valve outlet extending into the interior of the container, when fluid under pressure is applied to the outlet the valve member opens to allow said fluid to be dispersed radially outwardly via the outlet between the valve seat and the valve face.

2.A valve as claimed in claim 1 wherein the outlet includes a pressure equalising chamber defined by the body, the valve stem, and the valve face.

[3].A valve as claimed in claim 1 or claim 2 wherein the valve body is provided with a fluid chamber at the end opposite to the fluid outlet and into which the valve stem extends, said valve stem mounting a piston accommodated within the fluid chamber and inlet means communicable with opposite sides of the piston, such that by the application fluids under different pressures to opposite sides of the piston will cause the valve member to reciprocate to and from open to closed positions.

4.A controllable valve substantially as herein described with reference to the accompanying drawings.”

The specification included figures showing one possible embodiment of the invention and figure 1 was a drawing in the following form:

As most of the hearing was taken up with the issue of infringement I will consider that issue before turning to invalidity.

The relevant issues on infringement before the Court relate to:

(a)the meaning of “a controllable valve”;
(b)whether the respondents’ valve had a valve face with an arcuate surface;
(c)what the claims say as to the extent of the arcuate surface of the valve face;
(d)the meaning of “overhang the valve seat”;
(e)whether the fluid escapes from the respondents’ valve at right angles to the length wise axis of the valve member.

The issues substantially involve a consideration of the first claim. The other three claims are directly or indirectly dependent on claim 1. For the purposes of understanding the evidence the parties approached the first claim on the basis that it could be analysed and understood by reference to five integers:

“1.      A controllable valve comprising
-          a body,
-          a valve member mounted within the body,

2.        said valve member comprising
-          a stem mounted for reciprocation within the body and
-          a valve head opening to and positioned at one end of the body,
-a fluid outlet positioned at the same end of the body including a valve seat upon which a valve face of the valve head may rest,

3. said valve face being provided with
-an arcuate surface the outer peripheral extremities of which overhang the valve seat,
-so as to direct fluid escaping from the outlet radially outwardly and at right angles to the lengthwise axis of the valve member,

4.and (said valve further comprising) means communicable with said fluid outlet by which the valve may be connected (to) fluid under pressure,
5.the construction and arrangement being such that,
-in use, with the valve mounted in the wall of a container and the valve outlet extending into the interior of the container,
-when fluid under pressure is applied to the outlet
-the valve member opens to allow said fluid to be dispersed radially outwardly via the outlet between the valve seat and the valve face.”

Principles of construction

The initial questions which arise for consideration by the Court depend upon the proper construction of the claims. There has been much learning on the proper approach a court should take when a patent specification falls for consideration. It is helpful to recall and be guided by the principles laid down in three cases in particular. In Catnic Components Limited & Anor v Hill & Smith Limited [1982] RPC 183 Lord Diplock, speaking for the House of Lords, said at 242 ‑ 243:

“My Lords, a patent specification is a unilateral statement by the patentee, in words of his own choosing, addressed to those likely to have a practical interest in the subject matter of his invention (i.e. ‘skilled in the art’), by which he informs them what he claims to be the essential features of the new product or process for which the letters patent grant him a monopoly. It is those novel features only that he claims to be essential that constitute the so‑called ‘pith and marrow’ of the claim. A patent specification should be given a purposive construction rather than a purely literal one derived from applying to it the kind of meticulous verbal analysis in which lawyers are too often tempted by their training to indulge. The question in each case is: whether persons with practical knowledge and experience of the kind of work in which the invention was intended to be used, would understand that strict compliance with a particular descriptive word or phrase appearing in a claim was intended by the patentee to be an essential requirement of the invention so that any variant would fall outside the monopoly claimed, even thought it could have no material effect upon the way the invention worked.
The question, of course, does not arise where the variant would in fact have a material effect upon the way the invention worked. Nor does it arise unless at the date of publication of the specification it would be obvious to the informed reader that this was so. Where it is not obvious, in the light of then‑existing knowledge, the reader is entitled to assume that the patentee thought at the time of the specification that he had good reason for limiting his monopoly so strictly and had intended to do so, even though subsequent work by him or others in the field of the invention might show the limitation to have been unnecessary. It is to be answered in the negative only when it would be apparent to any reader skilled in the art that a particular descriptive word or phrase used in a claim cannot have been intended by a patentee, who was also skilled in the art, to exclude minor variants which, to the knowledge of both him and the readers to whom the patent was addressed, could have no material effect upon the way in which the invention worked.”

In Populin v HB Nominees Pty Ltd (1982) 41 ALR 471 the Full Court of the Federal Court (Bowen CJ, Deane & Ellicott JJ) said at 476:

“The complete specification must not be read in the abstract but in the light of common knowledge in the art before the priority date, bearing in mind that what is being construed is a public instrument which must, if it is to be valid, define a monopoly in such a way that is not reasonably capable of being misunderstood (see generally Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at 610). The essential features of the product or process for which it claims a monopoly are to be determined not as a matter of abstract uninformed construction but by a common sense assessment of what the words used convey in the context of then‑existing published knowledge”.

Similar observations were made by members of the Full Court of the Federal Court in Decor Corporation Pty Ltd & Anor v Dart Industries Inc (1988) 13 IPR 385. At 391 Lockhart J said:

“To be fairly based the invention claimed must be the same invention which is described in the body of the specification; the claim or claims must be fairly based on what has been described and must not seek to extend the patentee’s monopoly beyond this. The patentee is only permitted to claim what he has invented: see Ricketson, The Law of Intellectual Property, 1984, para 49.93. The function of the claims is to define clearly and precisely the monopoly claimed. Their primary object is to limit and not to extend the monopoly: see Electric & Musical Industries Ltd v Lissen Ltd (1938) 56 RPC 23 at 29, per Lord Russell; Ballantyne v Aktiebolaget Separator (1915) 19 CLR 620 at 628, per Isaacs J.
It is well established that there are no special rules for the interpretation of patent specifications, which are to be interpreted in the same way as any other written document upon ordinary principles of interpretation. The words used in a specification are to be given the meaning which the normal person skilled in the art would attach to those words, both in the light of his own general knowledge and in the light of what is disclosed in the body of the specification: British Thomson‑Houston Co Ltd v Corona Lamp Works Ltd (1921) 39 RPC 49 per Viscount Haldane at 67, per Lord Shaw at 89; Monsanto Co v Commissioner of Patents (1974) 48 ALJR 59 per Stephen J at 60.
In one sense it is right to say that the specification must be read as a whole, but the specification is a whole made up of several parts and those parts have different functions. It is not legitimate to reduce or enlarge the meaning of the words of a claim by glosses derived from other parts of the specification, or to confine the scope of the claims by reference to some limitation which may be found in the body of the specification but is not expressly or by inference reproduced in the claims themselves. In ascertaining the width of a particular claim it is not permissible to vary or qualify the plain and unambiguous meaning of the claim by reference to the body of the specification: Welch Perrin & Co Pty Ltd v Worrell (sic) (1961) 106 CLR 588, per Dixon CJ, Kitto and Windeyer JJ at 610. However, if an expression in the claim is not clear, it is then permissible to resort to the body of the specification in order to define or clarify the meaning of words used in the claim without infringing the rule that clear and unambiguous words in the claim cannot be varied or qualified by reference to the body of the specification: Electric & Musical Industries Ltd v Lissen Ltd, supra; Rosedale Associated Manufacturers Ltd v Carlton Tyre Saving Co Ltd [1960] RPC 59 per curiam at 69; Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461, per Barwick CJ, and Mason J at 479.”

Sheppard J having analysed a number of relevant authorities summarised (at 400) the relevant rules of construction which could be distilled from the authorities in the following way:

“(1) The claims define the invention which is the subject of the patent. These must be construed according to their terms upon ordinary principles. Any purely verbal or grammatical question that can be answered according to ordinary rules for the construction of written documents is to be resolved accordingly.

(2)      It is not legitimate to confine the scope of the claims by reference to limitations which may be found in the body of the specification but are not expressly or by proper inference reproduced in the claims themselves. To put it another way, it is not legitimate to narrow or expand the boundaries of monopoly as fixed by the words of a claim by adding to those words glosses drawn from other parts of the specification.
(3)      Nevertheless, in approaching the task of construction, one must read the specification as a whole.
(4)      In some cases the meaning of the words used in the claims may be qualified or defined by what is said in the body of the specification.
(5)      If a claim be clear, it is not to be made obscure because obscurities can be found in particular sentences in other parts of the document. But if an expression is not clear or is ambiguous, it is permissible to resort to the body of the specification to define or clarify the meaning of words used in the claim.
(6)      A patent specification should be given a purposive construction rather than a purely literal one.
(7)      In construing the specification, the court is not construing a written instrument operating inter partes, but a public instrument which must define a monopoly in such a way that it is not reasonably capable of being misunderstood.
(8)      The body, apart from the preamble, is there to instruct those skilled in the art concerned in the carrying out of the invention; provided it is comprehensible to, and does not mislead, a skilled reader, the language used is seldom of importance.
(9)      Nevertheless, the claims, since they define the monopoly, will be scrutinised with as much care as is used in construing other documents defining a legal right.
(10)     If it is impossible to ascertain what the invention is from a fair reading of the specification as a whole, it will be invalid. But the specification must be construed in the light of the common knowledge in the art before the priority date.”

(See also Glaverbel SA v British Coal Corporation [1994] RPC 443, 485 ‑ 487.)

The patent is a combination patent, that is to say it consists of a combination of integers, which combination is said to produce a new or improved result. There was no dispute that none of the elements claimed was new in itself but rather what is claimed to be new is the relationship between the elements claimed to produce the new or improved result. It is the relationship between the old or known integers which gives rise to the patent protection not simply the collection together of those known integers. The principle was expressed in British Celanese Ltd v Courtaulds Ltd (1935) 52 RPC 171 at 193 as follows:

“It is accepted as sound law that a mere placing side by side of old integers so that each performs its own proper function independently of any of the others is not a patentable combination, but that where the old integers when placed together have some working inter‑relation producing a new or improved result then there is patentable subject‑matter in the idea of the working inter‑relation brought about by the collocation of the integers.”

In Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 Aickin J said at 266:

“The patent thus claimed is a combination patent in the proper sense of that term, i.e. it combines a number of elements which interact with each other to produce a new result or product. Such a combination may be one constituted by integers each of which is old, or by integers some of which are new, the interaction being the essential requirement.”

The principle was re-stated more recently by Wilcox J in Interact Machine Tools (NSW) Pty Ltd v Yamazaki Mazak Corporation (1993) 27 IPR 83 at 99:

“To grant a patent is to grant a monopoly over a particular item. Where no integer is new, that grant is justified only by the contribution to science and industry made by the person who brought together particular old integers in a ‘working interrelation producing a new or improved result’. Assuming that this contribution involves an inventive step, and the patent application is not open to objection on other grounds, the inventor is entitled to a grant of a patent in respect of the particular combination which he or she devised. There would be no logic in granting the inventor rights in respect of a different combination, which he or she did not devise, even though the second combination might employ similar principles and achieve the same practical result”.

(See also Fallshaw Holdings Pty Ltd v Flexello Castors and Wheels PLC (1993) 26 IPR 565, 568 ‑ 569).

In order to establish infringement of a combination patent it is necessary that the patentee show that the respondent “has taken each and every one of the essential integers of the patentee’s claim”: Populin v HB Nominees Pty Ltd (supra) 475. If a respondent omits one of the integers in the combination in its product it will escape liability for infringement. However immaterial variations will not avoid liability.

Expert evidence

Each party relied on expert evidence. The applicant called an expert consulting engineer Mr Karel Lohning. A principal affidavit and an answering affidavit of Mr Lohning were filed and he was cross‑examined. Mr Lohning is a consulting engineer with extensive practical experience in the design and supervision of the manufacture of a variety of machinery. Mr Lohning gave evidence as to his understanding of the claims and the specification as one skilled in the art and as to the measurements he had made and supervised in respect of the respondents’ valve. In a number of respects to which I shall refer Mr Lohning’s evidence was unsatisfactory and inconsistent and at times he was unwilling to answer questions which were susceptible of a straight answer. The respondents’ expert Dr Pullum has extensive academic and practical experience in relation to mechanical engineering and the control, movement and transport of particles by fluid. He filed a principal affidavit and was cross‑examined. Like Mr Lohning, Dr Pullum gave evidence as to his understanding of the claims and the specification as one skilled in the art and as to the measurements he had made in respect of the respondents’ valve. I found Dr Pullum a more credible and reliable witness than Mr Lohning. He was more responsive and direct in answering questions whereas Mr Lohning was less inclined to be responsive.

I turn to the issues which arose in relation to the proper construction of the claims.

What is a “controllable valve”?

Claim 1 describes the valve the subject of the invention as being a “controllable” valve. The respondents say that the expression is ambiguous but at the least it adds something substantive to the expression “valve”. Dr Pullum did not suggest that “controllable” bore a special engineering meaning but said that the expression “controllable valve” was known in the valve manufacturing industry in Australia to denote a valve which can be controlled by suitable control means so as to be actuated to be fully closed, fully open or, if required, held at an intermediate position between these two positions. The respondents contend that the use of “controllable” in claim 1 was a reference to something more than a mere valve, that is to say it possessed an additional characteristic. The applicant contends that the meaning is clear, that is to say “controllable” is a reference to the fact that the valve can be adapted to be actuated from an open to a closed position as a function of real time.

Mr Lohning said that the term “controllable” was not a technical word and meant that there was a means of control of a valve opening and closing whenever the valve was in use. He said that all valves are controllable in the broad sense that the source of the movement of the valve member was capable of being switched on or off and the movement commenced or ceased. He said that “controllable” meant that the opening and closing of the valve were events which are a function of real time, the means of controlling the valve were well‑known and that the expression “controllable” added something to the description of the valve as it explained that it could be opened and closed at will. He said that the claims did not allow for an intermediate position between open and closed and there were no engineering means or need for the valve to stop in other than an open or closed position. However, he said that the valve could be made to have an intermediate position but that it would be very costly to make.

Helpful and informative as the expert evidence may be, the question of construction of the language used in the claims, particularly when it is not language with a technical meaning, is for the Court.

A valve is, by definition, a means by which a flow of fluid from one part or area to another part or area is controlled. When one refers to a valve one is recognising that there is a means usually external to the valve by which the flow through the valve is activated and the valve is made to operate. The Oxford Dictionary defines a valve as:

“A device of the nature of a flap, lid, plug etc applied to a pipe or aperture to control the passage of air, steam, water or the like, usually acting automatically by yielding to pressure in one direction only.”

In general terms a valve may completely inhibit a flow of fluid, or it may restrict or reduce a flow of fluid or it may commence a flow of fluid depending upon its particular application. To that extent a valve controls the fluid which flows through it or confronts it depending upon the manner in which it is actuated or activated.

Although it is inherent in the concept of a valve that it controls the fluid which flows through it it does not follow that the description of a valve as “controllable” in the context of the claims under consideration is a description of a valve with an additional characteristic. The description of a valve as “controllable” can also be a description of a valve that has the characteristic of being able to be activated and made to operate by an external stimulus. It is important to construe “controllable valve” in claim 1 by reference to the whole of claim 1. One does not find in claim 1 any reference to the manner in which, or extent to which, the valve is controllable other than that the valve member opens when fluid under pressure is applied to the outlet which fluid escapes from the outlet radially outwardly underneath the valve head.

Dr Pullum said that the expression “controllable valve” was known in the valve manufacturing industry in Australia to denote a valve which can be controlled by suitable control means so as to be actuated to be fully closed, fully open or, if required, held at an intermediate position between these two positions. There is nothing in any of the claims which suggests that the holding of the valve at an intermediate position between fully closed and fully open is required. The only movement suggested by claim 1 is that the valve opens and closes.

In my view the expression “controllable valve” in claim 1 is not ambiguous and is apt to describe and is descriptive of a valve which is adapted to be made to open and close by the application of an external stimulus such as the application of a fluid under pressure. In the context of claim 1 I regard the expression “controllable” as emphatic rather than as redundant that is to say it is describing the inherent characteristic of a valve as a means which can be activated to open and close. I do not consider that the reference to a “controllable valve” in the claims is that a factor is being added to the characteristics of the valve in addition to the manner in which it is activated or made to operate.

It was submitted by the respondents that reference to the specification in its original form before amendment (to which reference may be made in accordance with s 116 of the Act) supported the construction for which they contended. However an analysis of the specification before amendment does not support this construction.

In its unamended form claims 1 and 2 were in the following terms:

“1.A diffuser valve comprising a body, a valve member mounted within the body, said valve member comprising a stem mounted for reciprocation within the body and a valve head opening to and positioned at one end of the body, a fluid outlet positioned at said one end of the body and including a valve seat upon which a valve face of the valve head may rest, and means communicable with said fluid outlet by which the valve may be connected to a fluid under pressure, the construction and arrangement being such that, in use, with the valve mounted in the wall of container and the valve outlet extending into the interiors of the container, when fluid under pressure is applied to the outlet the valve member opens to allow said fluid to be dispersed via the outlet between the valve seat and the valve face.
2.A diffuser valve as claimed in claim 1 wherein the valve face is provided with an arcuate surface, the outer extremities of which overhang the valve seat such that fluid escaping from the outlet is directed substantially at right angles to the lengthwise axis of the valve member, and across the surfaces of the interiors of the container to which the valve is fitted..”

There then followed five further claims, each of which commenced:

“A diffuser valve as claimed [in previous claims].”

The seventh claim was in the form:

“A diffuser valve substantially as herein described with reference to the accompanying drawings”.

By the amendment the word “diffuser’ was deleted before “valve” in claims 1, 3, 4 and 7 and “controllable” substituted for it in claims 1 and 7 (claims 2, 5 and 6 being deleted), claims 1, 3, 4 and 7 becoming claims 1, 2, 3 and 4. However the text of claim 2 was pasted in to claim 1 in the following manner:

“A ~~diffuser~~ controllable valve comprising a body, a valve member mounted within the body, said valve member comprising a stem mounted for reciprocation within the body and a valve head opening to and positioned at one end of the body, a fluid outlet positioned at ~~said one~~ the same end of the body ~~and~~ including a valve seat upon which a valve face of the valve head may rest, said valve face being provided with an arcuate surface the outer peripheral extremities of which overhang the valve seat so as to direct fluid escaping from the outlet radially outwardly and at right angles to the lengthwise axis of the valve member and means communicable with said fluid outlet by which the valve may be connected ~~to a~~ fluid under pressure, the construction and arrangement being such that, in use, with the valve mounted in the wall of a container and the valve outlet extending into the interiors of the container, when fluid under pressure is applied to the outlet the valve member opens to allow said fluid to be dispersed radially outwardly via the outlet between the valve seat and the valve face.”

The respondents submitted that this amendment demonstrates that “controllable” was specifically added in order to provide an added characteristic to the characteristics inherent in the nature of a valve. But the substitution of “controllable” for “diffuser” as the description of the valve must not be looked at in isolation without regard to the other amendments. Those other amendments are not such as to suggest that the amendments taken as a whole were changing, or adding to, the characteristics of the valve in the sense that by describing it as a “controllable valve” rather than as a “diffuser valve” an additional characteristic was being claimed for the valve. Rather the amendment was making it clear what was the direction of the flow of the fluid through the valve.

Put shortly, a controllable valve is one which is adapted to open and close on the application of an external stimulus to fluid passing through it or to be passed through it.

What is the location of the valve face?

Integer 2 of claim 1 requires the valve member to have a valve head with a valve face and integer 3 of claim 1 requires that the valve face be provided with an arcuate surface. Mr Lohning agreed that the presence of the arcuate surface was one of the central requirements of the claims in the patent. The significance of the valve face is that the specification requires a seal to be formed between the valve head and the body of the valve on retraction of the valve head by the underside of the valve head interacting with a valve seat located on the body of the valve. The valve face also performs a function in relation to the direction of fluid. In general terms the valve face is located on the underside of the valve head. But where?

The location and extent of the valve face was a matter of considerable debate. Mr Lohning’s initial view (which changed) was that the valve face was “the underside of the valve head facing or opposite to the external face of the body of the valve at and about the valve seat location”. Dr Pullum agreed with Mr Lohning’s initial view and said that he would not normally associate the entire underside of a valve body as being a valve face. He said that in his experience a valve seat and a valve face work in collaboration and are in associated areas. For reasons to which I shall refer I do not consider this to be the proper construction of claim 1.

However Mr Lohning’s view changed from time to time. He had also said in his affidavit that the curve of the valve face is traced “in a radially outwardly direction from the centre line or lengthwise axis of the valve member” which suggests that the valve face is more extensive than he had initially stated.

In cross‑examination he described the valve face in these terms:

“the valve face is normally ... considered to be that part of the valve that engages with the valve seat and the valve seat does not have to be a knife edge for that rule to apply.”

He elaborated on this by agreeing that the valve face is the area immediately surrounding the underside of the valve head which makes contact with the valve seat or is the area proximate to the valve seat.

Shortly afterwards he said that he could see no direction in the claims as to where the arcuate surface has to be on the valve face. When it was put to him that a normal skilled person such as a machinist making a valve would take the claim to mean that the valve face was “the vast majority of the underside of the valve head” he responded:

“I don’t think that it would be fair to say that. I couldn’t say that the majority of the underside of a valve should be arcuate. That would be putting words as it were to the claim’s mouth. No, I can’t do that. I can only say what’s in the claim, I can only read what’s in the claim. The claim does not, the claims do not stipulate the extent of the arcuate surface”

This is an important matter because Mr Lohning agreed that the requirement for an arcuate surface was for a surface which has some relevant functional operation.

Mr Lohning then said that the valve face was the area “called up as number 7” in the drawing in figure 1 in the specification (page 5 of these reasons). This was a reference to most, if not all, of the underside face of the valve head. In order to clarify the matter Mr Lohning was asked to draw a diagram on a whiteboard showing the valve face. His first drawing identified the valve face as being located between the end of the curve of the valve stem and the commencement of the curve towards the outer periphery of the valve head. This included the area proximate to the valve seat location. Later he said he intended the line indicating the valve face to end immediately above the valve seat. He was then asked again what his view of the valve face was and he replied:

“The valve face, I think, is really the whole of the underside of the valve.”

The following exchange then occurred:

“You are saying that the claim refers to the whole of the underside area going to the outer periphery as being the valve face?‑‑‑That’s what I think it does.
Well, if I may, why did you draw that line there as a valve face as you did initially?‑‑‑Well, that’s - I meant here that this portion being flat will be the portion that contacts that knife‑edge. This can’t, but I’d be quite happy to extend that to there. I’d be quite happy to do that.
You are quite happy to extend the line of the valve face outwards to the edge of the periphery of the underneath of the valve head?‑‑‑Yes. I’d be inclined to do that, because the patent does it and I know engineers do it and I’ve probably done it myself.
When you say ‘the patent does it’, do you mean the claim does it?---The claims do it, yes.”

I found Mr Lohning’s evidence most confusing on this issue. The drawing and exchange to which I have referred occurred before the lunch adjournment. After lunch an agreed drawing of what Mr Lohning had drawn on the whiteboard was tendered and Mr Lohning made it clear that when he first drew the line indicating the valve face he intended it to end immediately above the valve seat. He also repeated his opinion that the valve face in figure 1 of the specification and his exhibited drawing of the invention incorporating the features of the invention described in claim 1 was constituted by the entire underside of the valve head from the end of the curve on the valve stem to the outer periphery of the head. Mr Lohning was then asked to repeat his drawing on the whiteboard which he did showing the valve face as running underneath the valve head from the end of the curve at the valve stem to the outer periphery of the head.

He was then taken to paragraph 23 of his affidavit and asked where on his drawing was the valve face. He indicated in the area of the valve seat and he said it was not down at the outer peripheral edge of the valve head. The following exchange then occurred:

“Well, you would say; would you that in practical terms the valve face should not really go right down to the outer peripheral edge?‑‑‑In this particular embodiment it can’t.
Right?‑‑‑But only in this embodiment.
Yes, well, we are confining our attention to this drawing at the moment?‑‑‑Mm.
My question was where on this drawing is the valve face?‑‑‑Mm.
Well, your answer?‑‑‑Well, my answer is that it’s - the valve face is approximately to the valve seat.
In accordance with paragraph 23 of your affidavit?‑‑‑Yes.

Yes. Well, are you inclined to change the indication on that drawing about where the valve is?‑‑‑I could change it, your Honour. If I were to be asked where the active portion of the valve face is, it would be approximate to the valve seat, but in engineering usage, the valve face is often the same as the under‑side of the valve. It’s often called - the under‑side of the valve is often called the valve face.”

He said that on his second drawing and on the drawing exhibited to his affidavit the valve face was that part of the underside of the valve head at and about the valve seat location. He was then asked whether he wished to reconsider where he had described the position of the valve face on his first drawing and he then showed it as the area at and about the valve seat location.

His cross‑examination was not concluded at the end of the day and on the next morning he said that he had looked at the patent overnight and now said that the valve face was the whole of the underside of the valve head. He said that this is what the patent specification said and that he had changed his view by reading the patent. He was influenced not by the claims alone but by the content of the specification including the figures. But that is not the point. What changed his view was “simply the patent itself”. When he was asked why he had vacillated about his view of the definition of the valve face he said:

“Well I can’t really answer that one. I mean I can only tell you how I feel at the time and how I feel now, after having ... I’ve changed my view simply by reading again the patent document.”

He must therefore either have mis‑read or misunderstood the patent on a fundamental issue when he prepared his first affidavit and when he gave evidence in the witness box.

I found his explanation for his change of evidence unconvincing. In paragraph 7 of his principal affidavit he said he had read the specification for the letters patent and he described in considerable detail the various integers in the claims. I assume that when he read the patent for the purposes of preparing his affidavit he would have done so with care having regard to the purpose for which the affidavit was required. His initial view that the valve face was the underside of the valve head facing or opposite to the external face of the body of the valve at and about the valve seat location was maintained with some variations during his initial cross‑examination and it was only after somewhat vigorous cross‑examination that overnight he changed his view. Mr Lohning’s change of position on such a fundamental issue gave me little confidence that I could regard his evidence as reliable.

Notwithstanding that Mr Lohning gave extensive evidence albeit inconsistent, in relation to the location and extent of the valve face, that issue is one of the proper construction of claim 1 and is therefore an issue for the Court to resolve. It is not a matter for expert evidence, especially where it is not suggested that the expression “valve face” is ambiguous. It was not put that the words “valve face” had a special technical or engineering meaning.

The identification of the valve face is important for the issue of infringement because it has a consequence in relation to the nature and extent of the arcuate surface required and what is required by claim 1 to overhang the valve seat.

When read in context I do not consider there is any ambiguity as to what is the valve face or where it is to be located. The valve face is one of the components of the valve member; it is first mentioned in claim 1 as “a valve face of the valve head”. It is said in claim 1 that the valve face may rest upon a valve seat. Thus far, in my opinion, there is no reason to limit the valve face to the area of the underside of the valve head at or proximate to the valve seat. This is made clear, in my view, by the fact that claim 1 says that the valve face is provided with an arcuate surface “the outer peripheral extremities of which” overhang the valve seat. So described the expression “of which” is a reference back to the arcuate surface of the valve face. Accordingly the valve face extends to the outer peripheral extremities of the underside of the valve head. The reference to outer peripheral extremities is, in my view, a reference to an end or an edge so that in context it means the underside of the rim or outer edge of the valve head. But how far in from that edge past the point opposite the valve seat is the valve face to extend? No limit or point is specified but there is no need to do so having regard to the fact that the valve face is the “valve face of the valve head”. Accordingly the valve face extends inwardly towards the stem of the valve member up to the point at which it meets the curve of the valve stem. In the context of claim 1 I can see no reason to limit the valve face to the underside of the valve head at and about the valve seat location particularly when it extends to the outer peripheral extremities of the underside of the valve head.

Where is the arcuate surface of the valve face positioned?

A consideration of the arcuate surface of the valve face has two aspects to it. First the definition of “arcuate” which I take to be “curved”. It was not disputed that arcuate meant curved in the sense of having a radius of curvature. Both experts agreed that “arcuate” did not bear a special engineering meaning. Secondly, one has to ask but what sort of curve? Is it a curve which is visible to the naked eye or a curve which can be measured and exposed by scientific equipment readily available to those skilled in the art?

I consider that there is no ambiguity as to what claim 1 requires as to the location and extent of the arcuate surface of the valve face; it is co‑extensive with the extent of the valve face. To say that the valve face is provided with an arcuate surface is, in my view, to say that the whole of the valve face is so provided. I do not see the ambiguity suggested by Dr Pullum when he said he did not know whether the valve face itself has an arcuate surface or whether the valve face accompanies an arcuate surface in the sense of having an arcuate surface stuck on. If the intention was the latter I would expect the language to be quite different. The words in integer 3 of claim 1 “so as to direct fluid escaping from the outlet radially outwardly and at right angles to the lengthwise axis of the valve member” do not negate this view or require a contrary conclusion. Even if it be said that it is, what I will call loosely, the overhanging part of the surface of the valve face which is designed for, or achieves, that result, it does not follow that that part of the valve face which is positioned between opposite the valve seat and the commencement of the curve of the valve stem cannot have an arcuate surface. Mr Clarke who appeared for the applicant, in the course of submissions asked how, on this construction could it be said that the portion of the valve face from the plane of the valve seat to the commencement of the curve of the valve stem could possibly direct in any relevant sense the flow of the fluid escaping radially outwards and at right angles to the lengthwise axis of the valve member? The short answer to that submission is that according to claim 1 it is the overhanging of the outer peripheral extremities of the arcuate surface of the valve face which perform that task.

I also consider that the proper construction of integer 3 of claim 1 is that the arcuate surface is required to be a continuous curve rather than a series of curves. Put colloquially, the arcuate surface is to be curved rather than curvy or in the shape of a roller‑coaster. It is inherent in the expression “arcuate surface” that a continuous curve is required. If a series of curves, or at the least, more than one curve is required, the language used would be different.

Mr Lohning said as much in his principal affidavit:

“As the outer peripheral extremities are to overhang the valve seat, it is apparent to me that the curve is to be in a downwards direction when the valve is viewed in cross‑section and the curve is traced in a radially outwardly direction from the centre line or length wise axis of the valve member”.

I understood that by this evidence Mr Lohning was saying that the whole of the surface of the valve face was curved and not flat but Mr Lohning disavowed this interpretation. He said there was no direction in the claims as to where the arcuate surface was to be positioned on the underside of the valve. It will be remembered that the relevant part of claim 1 states “said valve face being provided with an arcuate surface the outer peripheral extremities of which overhang the valve seat ...”. Mr Lohning said that one could not say that the majority of the valve face was to be arcuate as the claim did not indicate the extent of the arcuate surface.

I do not find Mr Lohning’s evidence convincing in this respect and I am not assisted by it on the issue of construction. In any event the issue of construction is one for the Court and I have reached a firm conclusion on this issue of the location of the valve face for the reasons to which I have referred.

In the primary material filed the applicant was saying it was the outer peripheral extremities of the valve face which overhang the valve seat whereas the respondents were saying that it was the arcuate surface of the valve face which overhangs the valve seat. The resolution of this issue is a matter of construction and depends upon the proper construction of the word “which” which appears in integer 3. Does “which” refer to the valve face or alternatively, does it refer to the arcuate surface of the valve face? In cross‑examination the distinction between the parties seemed to become blurred. It was put to Mr Lohning that the reference to “the outer peripheral extremities” in integer 3 was a reference to the valve face being provided with an arcuate surface. Mr Lohning’s initial answer was in the negative as he understood that reference to be to the outer peripheral extremities which overhang the valve seat. He was then asked “the outer peripheral extremities of what?” And his answer was “of the arcuate surface”. Mr Lohning was then asked:

“So do you mean to suggest, then, that the overhanging peripheral extremities of the under‑side of the valve head must be arcuate?”

Mr Lohning’s answer was:

“Yes, and in fact, they’re shown that way, your Honour, on the figure 1.”

This is the conclusion I have reached as a matter of the proper construction of claim 1.

Meaning of “overhang the valve seat”

It was submitted that there was ambiguity in the expression “overhang the valve seat”. It could mean either “looms over” (as the respondents contended) or “extends radially outwards and beyond (as the applicant contended).

Mr Lohning described how the outer extremities of the valve face overhang the valve seat in the sense that they projected beyond and past the valve seat and that it was this feature together with the arcuate shape of the valve face which caused the escape of air radially outwards from the valve thereby fluidising granular material within a hopper.

It was not clear to Dr Pullum whether claim 1 required that the outer peripheral extremities of the arcuate surface of the valve face merely hang over or be suspended over the valve seat below or whether it was also required that the outer peripheral extremities of the arcuate surface of the valve face must extend radially outwards from and beyond, or project past, the valve seat below. In other words, it was not clear whether claim 1 required the valve face to have a greater radius than the valve seat. In his opinion either configuration would direct escaping fluid in a radially outwards direction. However, he said, neither configuration would direct escaping fluid at right angles to the lengthwise axis to the valve member required by claim 1. By contrast Mr Lohning understood the claim to require that the outer peripheral extremities of the valve face to be positioned radially outwardly from and beyond the valve seat and therefore that the valve face have a radius greater than the radius of the edge of the valve seat about the valve lengthwise axis. He said that if the claim required the outer peripheral extremities of the valve face to be positioned above, but not beyond, the valve seat and accordingly to be radially coincident to the valve seat, if it had a knife edge configuration in the contact between the valve face and the valve seat it would be in line contact in which case the sealing action of the valve could be easily impaired.

Mr Lohning said that if Dr Pullum was correct in identifying an ambiguity in the meaning of the word “overhang” then the ambiguity was resolved by recourse to the body of the specification including the figures which showed the escaping fluid as directed radially outwardly and at right angles to the longitudinal axis of the valve.

I do not consider there is any ambiguity as to the meaning of “overhang” in this context and it is not necessary to resort to the body of the specification in order to resolve the issue of the construction of “overhang”. In my view, the expression “overhang” is used in the sense of “extends radially outwards and beyond” and I reach this conclusion having regard to the context in which the expression appears. The valve face is said to rest on the valve seat. There is then a reference to the outer peripheral extremities of the arcuate surface of the valve face which are said to overhang the valve seat. It is not the outer peripheral extremities of the valve which rest on the valve seat, so as a matter of construction and commonsense it must be said that the outer peripheral extremities extend radially outwards and beyond the valve seat and do not just loom above but not beyond it.

The measurements of the surface of the valve face of the respondents’ valve

The measurements undertaken by Mr Lohning and the purpose of taking them were controversial and the subject of criticism. Mr Lohning set out in his initial affidavit how he undertook the task of measuring the valve face of the respondents’ valve for straightness. According to those measurements the valve face was not straight. However on this occasion he did not measure surface texture and he did not find any curves on the valve face as he was only measuring straightness.

Subsequently Dr Pullum’s affidavit was filed in which he criticised Mr Lohning’s methodology in relation to the measurements he had made. Dr Pullum explained how he had taken his measurements from which he had concluded that the valve face of the respondents’ valve was straight. Thereafter in April 1996 Mr Lohning undertook a further series of measurements of the valve face of the respondents’ valve. In his further affidavit he criticised Dr Pullum’s methodology and set out the further series of measurements he had undertaken to measure the surface roughness and waviness of the surface profile of the valve face.

Mr Lohning undertook a measurement task which extended over a considerable period on two separate occasions and involved measuring straightness, roughness and waviness by the use of expensive specialised equipment. Dr Pullum undertook a less rigorous approach by using equipment such as a standard engineer’s rule and vernier callipers which are readily available to those skilled in the art and are used in practice in engineering machine shops. Valves are machined to fine tolerances and it is usual for engineering drawings to specify the maximum degree of roughness, or variation from absolute smoothness which is permitted in micrometres. A micrometre is a measure of one millionth part of one metre. The drawing of the respondents’ valve which was produced specified a maximum surface roughness of 1.6 micrometres to be obtained by machining. Mr Lohning explained that surface roughness is an indication of the extent of irregularities in a surface texture which are inherent in the production process but it excludes waviness and errors of form. The micrometre measure of the maximum surface roughness is expressed as the maximum vertical variation from the horizontal straight line. The vertical measure is taken from the line of the lowest pit in the surface to the line of the highest protrusion from the surface. Viewed in cross‑section, surface roughness is the measure of surface height variations whereas waviness is that component of surface texture upon which roughness is superimposed.

Although one is dealing with extremely small measurements when measuring micrometres this is a task understood, accepted and undertaken by those skilled in the art. Dr Pullum produced an engineering drawing text which set out standard roughness values for various machinery processes and applications. These values covered a range from very smoothly finished surfaces to what was said to be a very rough finish and the range was from .025 to 25 micrometres. I therefore accept that persons skilled in the art are capable of working to the very fine measurements identified by Mr Lohning.

It is perhaps curious that there can be a controversy over whether a surface is straight or curved but the issue arises because the respondents intended the valve face of their valve to be straight and the claimed curve is microscopic. Mr Lohning accepted that the respondents’ drawing of the respondents’ valve provided for a straight valve face and that a curved valve face was not intended by the manufacturer. Mr Lohning said that what he called the curved part of the valve face of the respondents’ valve was curved because of the nature of the machining of the valve and the development of the curve was inherent in the machining. Of course, intention is irrelevant in this context, infringement being a question of fact. The relevant question is - does the valve face, in fact, have an arcuate surface in the sense required by integer 3 of claim 1 for whatever reason?

Mr Lohning had measured and supervised the measurement of the line of the radius of the valve head along the underside of the valve head. On the first occasion it was measured for straightness. Three measurements were taken across the underside of the valve head but not the whole of the underside was measured. The measurements showed a maximum surface height variation of 6.5 micrometres, 4.14 micrometres and 4.2 micrometres. The surface roughness revealed by the measurements exceeded the surface roughness of 1.6 micrometres required by the respondents’ drawing of the respondents’ valve. Mr Lohning deduced from the drawings that the underside of the valve head displayed what he called “substantial waviness and pronounced curvature”. He concluded that the shape of the valve face of the valve head was properly described as being arcuate in shape when viewed in cross‑section. However these measurements only measured the valve face for straightness, they did not measure whether the valve face was curved. On this occasion Mr Lohning did not find any curves on the valve face.

Dr Pullum’s affidavit was filed in December 1995 and in his affidavit he set out the manner in which he had measured the valve face of the respondents’ valve and concluded that it was straight and not curved. He also criticised Mr Lohning’s measurements as being inappropriate and having exceeded the bounds of practicality. Dr Pullum measured the valve face of the respondents’ valve in a manner quite different to that undertaken by Mr Lohning. Dr Pullum sectioned one of the respondents’ valve heads along the longitudinal axis of the valve stem and he applied a standard engineer’s 150mm rule to determine whether or not the face of the valve head was arcuate. He considered the use of a rule in this way to be the appropriate degree of scrutiny to determine whether or not the valve face was arcuate. He described in some detail in his affidavit how he went about the measuring task. His measurements of the valve face of the valve head showed the surface to be straight and not arcuate.

Mr Lohning was critical of Dr Pullum’s methodology and said it was wholly inappropriate. Dr Pullum had placed the engineer’s rule on the valve face and had observed whether light could be seen between the surface of the underside of the head and the rule edge. Mr Lohning said that the engineer’s rule cannot measure micrometres, that there is no certainty that the edges of a rule are straight and that the human eye cannot distinguish variations in the width of a band of light of the order of up to 6 micrometres.

There is a significant difference between the methodology adopted by Mr Lohning and the methodology adopted by Dr Pullum in measuring the underside of the valve face. Dr Pullum took the approach that the appropriate instruments for inspection of engineering components were those that operated at a scale of scrutiny commensurate with the nature and function of the equipment being used. He said that in respect of fluid flow valves, standard mechanical engineering instruments such as vernier callipers and a standard engineering rule are appropriate instruments and are used in practice in engineering machine shops to monitor and control components and to check the results of machining. He regarded Mr Lohning’s methodology as inappropriate and scientifically unsound because it was “an extreme exercise undertaken with recourse to techniques of metrology”; metrology is a highly specialised science of weights and measures. Dr Pullum did not consider metrology to be a science to which designers and manufacturers of valves would ordinarily turn to for guidance in determining tolerances or surface roughness necessary for the manufacture of efficient well‑made valve components. He said that the measurements taken and relied upon by Mr Lohning exceeded the bounds of practicality.

Dr Pullum’s substantial criticism of Mr Lohning’s measurements was that the variations they showed of 1.2 micrometres above and 1.4 micrometres below the mean over a distance of 3.2mm had no relevance to the matter in issue because the scale of scrutiny within which the valve face was being measured does not influence the operation of the valve in any way.

Dr Pullum therefore concluded that the valve face of the respondents’ valve was not in any practical sense arcuate in shape when viewed in cross‑section. He was of the opinion that the arcuate surface required by claim 1 was not a trivial surface irregularity but rather a feature readily able to be discerned and not an incidental microscopic variation.

I think there is substance in this argument, particularly when the object of the exercise of measurement is to determine whether the particular profile to be measured has a curve which has a function or purpose. It is not necessary to set out in any further detail the methodology used by each expert as I am satisfied that Mr Lohning’s method was not practical or appropriate to determine if the patent was infringed by the use of a curved valve face having regard to the context in which “arcuate” appears. It was a form of measurement taken to a level which although available, no doubt at a cost, to persons skilled in the art, was not a level which was practical.

I should also point out that Dr Pullum challenged the manner in which Mr Lohning had determined the surface roughness of the underside of the valve head of the respondents’ valve because he said surface roughness was not evaluated by measuring the distance between high and low peaks in the appropriate units but rather, for a cut‑off length exhibiting the profile a centre line is established and the sum of the area of peaks above the centre line plus the area of troughs below the centre line is divided by the cut‑off length. He demonstrated this approach by reference to an Engineering Drawing text. The result was, according to Dr Pullum, that Mr Lohning had overstated the extent of the surface roughness of the valve face.

However even if I am wrong in rejecting Mr Lohning’s methodology as appropriate in the circumstances for measuring whether the valve face of the respondents’ valve is curved, that methodology did not establish that the valve face was curved to the extent, or in the manner, required by integer 3 of claim 1. Mr Lohning did not measure the whole of the valve face to determine if the whole of the valve face was arcuate. Notwithstanding the detailed measurements which Mr Lohning undertook of the underside of the valve head of the respondents’ valve, the drawing and measurements upon which he relies to show the wavy nature of the surface is only a measurement of a distance 3.2mm radially inwards from the peripheral extremity of the valve face. The plane of the valve seat is located 4.999mm radially inwards from the same position. The reason why Mr Lohning could not measure any further radially inwards was due to the limitations of the equipment he was using. There is therefore no direct evidence that the valve face of the respondents’ valve is curved across the whole of the valve face, and in particular, up to and just past the plane of the valve seat.

The drawings Mr Lohning produced to demonstrate that the respondents’ valve face had an arcuate surface showed a curve but it was a microscopic curve and it was not measured over the whole of the area he considered to be the valve face. Although the drawing upon which he relied to show a curved surface showed a curve in graphic terms his graph co‑ordinates were not the same scale. The dimension of the vertical axis is plus or minus 1½ microns and the horizontal axis is 3mm so that if they were on the same axis and the same scale the horizontal axis would, according to Dr Pullum, be a thousand times longer and that would be sensibly straight. If the co‑ordinates had been to the same scale the horizontal co‑ordinate would have been considerably extended with the result that the valve face would not have presented as curved in the manner Mr Lohning presented it.

Mr Lohning said that in his second set of measurements he was measuring surface roughness which had nothing to do with identifying an arcuate surface. He said that a measurement of waviness was relevant to determining whether there was an arcuate surface and he said that his measurement of waviness produced more than one arcuate surface. Mr Lohning agreed that the curve he identified in the valve face would not increase or decrease the flow of fluid and would not affect the function of the valve. It was accepted by Mr Lohning that there was not a continuous curve over the valve face of the respondents’ valve, that is to say, he accepted that the face was not continuously arcuate in the sense of having one curve.

Does the respondents’ valve infringe the applicant’s patent?

Is the respondents’ valve controllable?

The respondents’ valve is controllable in the sense in which I have construed “controllable” in the claims. It can only operate on the application of external stimuli to the fluid which flows through it. It has no means within it which enables its operation to be controlled so that it can be fully opened or fully closed or held at any intermediate position between those two positions, but that is not a requirement of the controllable valve claimed in claim 1.

Does the valve face of the respondents’ valve have an arcuate surface?

I am satisfied that the valve face of the respondents’ valve is not arcuate either in the sense of being curved or alternatively so curved as to influence or affect in any way the flow of fluid emitted from the respondents’ valve when in operation. If I am wrong in this respect I am nevertheless satisfied that the valve face of the respondents’ valve is not continuously curved in the sense of having, or presenting, only one curve.

There is no evidence that the whole of the valve face of the respondents’ valve has an arcuate surface. In order to infringe the patent, according to the construction I have placed on the terms “valve face” and “arcuate surface” in the context in which they appear in the claims, it would be necessary for the valve face to comprise a continuous curve over the whole of the valve face between the outer peripheral extremities of the underside of the valve head, that is to say the valve face, and the commencement of the curve at the stem of the valve member. Mr Lohning was not able to measure the valve face of the respondents’ valve over the whole of this distance. It should also be noted that Mr Lohning did not measure right up to the extremity of the underside of the valve head.

Even if I were to assume, as the applicant submitted I should, that the measurement over the distance of 3.2mm could be extrapolated over the whole of the valve face it does not follow that the whole of the valve face comprises one continuous curve. In my opinion integer 3 of claim 1 requires a continuous curve, not a series of curves. Mr Lohning accepted that integer 3 of claim 1 should be read as requiring one arcuate surface but said that his measurements of the respondents’ valve disclosed that its valve face did not have a continuous curve. He also said that if he extrapolated his measurements over the whole of the valve face as I have defined it, he did not think there would be a continuous curve but rather there would be waviness undulations.

However it was submitted that even if I was to find that the whole of the surface was not arcuate I should find that it was substantially arcuate as a measurement of 3.2mm of a total distance of 4.999mm showed a substantially arcuate profile. However in the light of the fact that it was accepted that the face was not continuously arcuate I do not find that the valve face was substantially arcuate.

I am therefore satisfied that the respondents’ valve does not have a valve face provided with an arcuate surface such as to infringe integer 3 of claim 1. I am confirmed in this conclusion by the fact that what Mr Lohning says is the arcuate surface of the respondents’ valve face does not serve or perform any function as such. After some hesitation Mr Lohning accepted that the requirement in integer 3 of claim 1 for an arcuate surface related to a functional operation in the valve, that is to say it required a smooth curved surface, according to Mr Lohning “to appropriately direct the flow of the pressurised fluid”. Mr Lohning, however, said that the arcuate surface of the valve face of the respondents’ valve performed no relevant function and would not increase or decrease the flow of fluid.

Indeed, on one view, Mr Lohning misconceived his task when measuring the valve face of the respondents’ valve because he said he would not have reported the condition of its surface had the waviness depth (found to be 2.6 microns) been less than the figure of 1.6 microns quoted on the respondents’ valve drawing shown to Mr Lohning. A degree of roughness, of itself, is not indicative of a curve; that depends upon a further examination for waviness.

Does fluid escape from the respondents’ valve at right angles to the lengthwise axis of the

valve member?

This issue was a matter of controversy between the experts. Mr Lohning said that in excess of 98.481% of the fluid coming from the respondents’ valve was directed at right angles to the lengthwise axis of the valve member. He reached this conclusion by theoretical calculations and he did not test the respondents’ valve to observe the direction the emitting fluid would take. Dr Pullum disagreed and said that the escaping fluid would be directed downwards at an angle likely to be significantly less than 90° to the valve stem and not substantially parallel to the wall of the vessel. He thought it would be of the order of 40°.

It was put to Dr Pullum that this view was inconsistent with his observation in relation to the Gruen patent (to which I refer later) that when the valve was open the flow of fluid is radially outwards and substantially parallel to or at a slight angle to the surface to be cleaned. Dr Pullum saw no inconsistency and said that his explanation for his view of the Gruen patent was that he was looking at a different scale of scrutiny and that the fluid in the Gruen patent was dispelled in a swirling flow and was not being trained or directed by the underside of the valve head.

Dr Pullum said that as the underside the valve head of the respondents’ valve is straight and angled downwards the effect of the undersurface of the valve face and its outer periphery will be to divert escaping fluid downwards and not at right angles to the valve stem. He said that the under part of the issuing fluid flow would be parallel to the body of the valve or the surface of the vessel and that the upper part of the issuing fluid flow would be essentially parallel to the underside of the valve head or the valve face. He did not accept that such flow from the valve overall was parallel in the sense of being at right angles to the valve stem. He said that there would be friction within the flow and a dissipation and diffusing of the fluid.

Mr Lohning pointed out, the patent cannot predict the nature of the environment external to the valve so that the direction of escaping fluid can only be accurately predicated at the plane of the valve outlet. Accordingly Mr Lohning maintained his view that the direction of the fluid at the outlet of the respondents’ valve will be radially outwards and at right angles to the lengthwise axis of the valve member.

I found Mr Lohning’s evidence on this issue unsatisfactory. He based his conclusion that in excess of 98.481% of the flow from the respondents’ valve would be at right angles to the valve stem axis on calculations which he exhibited. He denied that the calculations were based on vector theory but then went on to explain and justify the conclusion and calculation by reference to a vector analysis.

I am faced with a conflict between the experts on the issue whether fluid from the respondents’ valve escapes at right angles to the lengthwise axis of the valve member. The evidence on this point is theoretical because neither expert tested the respondents’ valve in operation to determine the direction taken by the emitting fluid. I am reliant in this area on the experts and accordingly I must decide which evidence to accept. I found Dr Pullum more reliable in the manner in which he answered questions. By contrast, Mr Lohning’s answers were frequently not responsive to the questions put to him. From time to time Mr Lohning vacillated on issues which ought not to have been the subject of any doubt. In particular I found Mr Lohning’s significant change of evidence in relation to the extent and description of the valve face such as to indicate unreliability in relation to his evidence.

Overall I regard Dr Pullum as a more reliable and credible witness than Mr Lohning and I accept Dr Pullum’s evidence on this issue where it conflicts with Mr Lohning’s evidence. I am not satisfied that the respondents’ valve directs escaping fluid at right angles to the lengthwise axis of the valve member.

Claims 2, 3 and 4

The conclusions I have reached and findings I have made in relation to claim 1 resolve the issues of whether there is infringement in relation to claims 2, 3 and 4 as those claims are substantially dependent on claim 1. In particular there is nothing in the drawings which alters my conclusions in relation to the integers said to be infringed which I have found not to be infringed. I should also observe that the use of “substantially” in claim 4 is not of itself a vitiating factor: Leonardis v Sartas No 1 Pty Ltd (1996) 67 FCR 126, 134.

It follows from these findings that the respondents have not infringed the applicant’s patent.

Invalidity

Invalidity of the patent is asserted by the respondents on the grounds of:

Obviousness.
Want of novelty.
The specification does not describe the invention fully or include the best method known of performing the invention.
The claims are not fairly based on the matter described in the specification.
Ambiguity in the claims. I have found there is no ambiguity in the claims.

It was not an issue that the various components or integers of the invention were known before the priority date. However Mr Lohning did not agree that their combination in the patent was a matter of routine that anyone skilled in the art could have carried out. The prior art included the provision of air nozzles to hoppers so as to apply high pressure air to the material within the hopper. Mr Lohning regarded such a process as inefficient because it would punch a hole straight through the particulate matter. It was put to him that the scenario of a blast creating a hole in the material could be overcome by the use of a poppet valve to spread the high pressure air into the hopper and that this was not a difficult step to take. Mr Lohning disagreed and said that he was not aware before the priority date of any use of a poppet valve to admit pressurised air into a hopper to fluidise the material in it. He did not accept that it was a matter of routine to use a poppet valve flush mounted in a hopper to fluidise the particulate material in it.

By contrast Dr Pullum explained the sequence of reasoning by which he would have concluded at the priority date that by taking the steps to which he referred he would have overcome the problem caused when particular materials bridged or packed when stored in a hopper or a container.

The respondents’ submission on obviousness was that each step claimed in the patent was routine, unexceptional and lacking in invention. As Dr Pullum said, the valve described in the patent represented nothing more than a valve “the features of which would have been quite evident to me before April 1984”. However it is the combination of features which is important and although Dr Pullum set out the steps he would have taken prior to April 1984 to overcome the problem caused when particulate material bridged or packed when stored in a hopper I am not satisfied that the combination of features found in the applicant’s patent was obvious. It is not sufficient to identify particular integers and ask whether the addition of that particular integer was obvious.

In Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd (supra) Aickin J said at 293:

“The proper question is not whether it would have been obvious to the hypothetical addressee who was presented with an ex post facto selection of prior specifications that elements from them could be combined to produce a new product or process. It is rather whether it would have been obvious to a non‑inventive skilled worker in the field to select from a possibly very large range of publications the particular combination subsequently chosen by the opponent in the glare of hindsight and also whether it would have been obvious to that worker to select the particular combination of integers from those selected publications. In the case of a combination patent the invention will lie in the selection of integers, a process which will necessarily involve rejection of other possible integers. The prior existence of publications revealing those integers, as separate items, and other possible integers does not of itself make an alleged invention obvious. It is the selection of the integers out of, perhaps many possibilities, which must be shown to be obvious.
It is in relation to this process that the misuse of hindsight is most common. When once an idea or an object or a process or a combination, admittedly novel, has been published, it is very easy to say after perhaps months of search and study in the Patent Office and the public libraries that the integers into which the patent might be dissected could be found scattered amongst the prior documents by a person who already knew the solution to the problem and therefore knew what to look for and what to discard. But that process does not demonstrate lack of an inventive step. The opening of a safe is easy when the combination has been already provided.”

(See also Fallshaw Holdings Pty Ltd v Flexello Castors and Wheels PLC (supra).

I am not satisfied that the combination of integers set out in claim 1 was obvious in the terms required by s 7(2) of the Act (compare s 100(1)(e) of the 1952 Act) as at the priority date.

The respondents relied upon a body of prior art in support of the invalidity claim but no submissions were made in relation to the prior art. The Gruen patent (US Patent 4261075) described a valve for cleaning purposes. Mr Lohning said it did not comply with integer 1 of claim 1 as the pressured fluid itself actuated the valve rather than the valve controlling the flow of the fluid. However as I understand integer 3 it is the fluid under pressure which opens the valve member when it is applied to the outlet. Otherwise the Gruen valve complied with integers 2 and 4. It does not comply with integer 3 as its valve face does not have an arcuate surface and the peripheral extremity of the valve does not overhang the valve seat; nor is the emission of fluid uniform round the entire perimeter of the valve. It also does not comply with integer 5. It does not conform to claims 2, 3 or 4.

The Hager patent (US Patent 4261389) described a valve arrangement for injecting a gas into fluid suspensions such as polyvinyl chloride. Mr Lohning said it was not a controllable valve because no means of controlling the valve is claimed. However no means of controlling the applicant’s valve other than by describing it as “controllable” is claimed by the applicant. Although the Hager patent complies with integers 2 and 4 it does not comply with integers 3 and 5. In particular the valve face does not have an arcuate surface and the peripheral extremity of the valve does not overhang the valve seat. It does not conform to claims 2, 3 or 4.

The Fendt patent (British Patent Specification 1305085) is not a valve but rather involves a mechanism including a baffle through which compressed gas is passed. It has no valve member, no stem mounted for reciprocation and no valve seat. It does not conform to any of the claims of the applicant’s patent.

The Aoki patent (US Patent 3,949,963) relates to a drain valve albeit in the style of a poppet valve. Dr Pullum says it discloses a number of the integers of claim 1. Although it is a drain valve Dr Pullum says it could function as a dispersing valve. However it does not permit fluid under pressure to be connected to its fluid outlet and it has no valve face with an arcuate surface nor do the outer peripheral extremities of the valve face overhang the valve seat. It does not conform to any of the claims of the applicant’s patent.

The Barford patent (British Patent Specification 678800) is a device for filling bottles and the valve disclosed as part of the invention is used to disperse liquid into bottles. The valve does not have an arcuate valve face and the outer peripheral extremities of the valve face do not overhang the valve seat. Further the fluid escapes in an axial, not a radial direction. It does not conform to any of the claims of the applicant’s patent.

The Bey patent (US Patent 43357440) relates to a safety relief valve. Mr Lohning said it was not a controllable valve as it operates to open only when the fluid pressure at the inlet rises above a predetermined point. This is similar to the operation of the applicant’s valve. However the escaping fluid escapes from the outlet in the valve body in one radial direction and not radially outwards through 360°. The Bey patent does not comply with integer 3 of claim 1 nor does it conform to any of the other claims.

The respondents rely on a product sheet produced by W R Terry Fluid Controls Pty Ltd from which valves were made prior to 1983 by that company. However the valve face does not have an arcuate surface and fluid only escapes from the valve outlet in one radial direction. Further, it does not appear to comply with integer 5 of claim 1. It does not conform to any of the claims of the applicant’s patent.

Finally the respondents rely upon a sheet headed “‘1’ Poppet Valve for F6WS 81‑2S”. This was a sheet kept by W R Terry Fluid Controls Pty Ltd or one of its associated companies from which valves were made prior to 1983. The valve face is not arcuate. I cannot determine the means by which the fluid under pressure will open the valve. I am not satisfied that this poppet valve conforms to any of the claims of the applicant’s patent.

It was also submitted that the patent was invalid on the ground that the specification did not describe the best method known to the applicant of performing the invention. This was a reference to the pulsing of the valve or its intermittent operation, it being submitted that the evidence demonstrated that pulsing was the best method of operation. Although the evidence referred to intermittent operation of the valve giving a more satisfactory degree of fluidisation of particulates, I am not satisfied that the evidence went so far as to say that the best method of using the valve was in a continuous pulsing or intermittent operation.

Are the claims fairly based?

The respondents contend that the claims are not fairly based on the matter described in the complete specification. They contend that there is no fair basis for the requirements that the valve be “controllable” and that escaping fluid be directed “at right angles to the lengthwise axis of the valve member”. The construction I have placed on “controllable” valve is that the valve is controllable in the sense of being adapted to be made to open and close by the application of an external stimulus such as the application of a fluid under pressure and accordingly is appropriately described as “controllable”.

The word “controllable” does not appear in the body of the specification as an adjective descriptive of the valve the subject of the specification or otherwise, although the valve is so described in the claims. Nevertheless one finds in the body of the specification a sufficient description of the operation of the valve which makes it clear that there is a means communicable to the fluid outlet in the valve body by which the valve may be connected to a fluid under pressure and that it is when this fluid under pressure is applied to the fluid outlet that the valve member opens to allow the fluid to be dispersed through the fluid outlet between the valve seat and the valve face.

I consider that this description is a sufficient description of the controllable nature of the valve to enable it to be said that claim 1 insofar as it claims a “controllable” valve is fairly based on the matter described in the specification. The specification warrants and allows the conclusion that the valve is “controllable” in the sense to which I have referred.

The principles upon which a determination is to be made whether s 40(3) of the Act has been complied with, that is to say whether a claim is fairly based are well established. In Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 Gummow J said at 95:

“... the question is whether there is a real and reasonably clear disclosure in the body of the specification of what is then claimed, so that the alleged invention as claimed is broadly, that is to say in a general sense, described in the body of the specification.”

In CCOM Pty Ltd v Jiejing Pty Ltd (1994) 51 FCR 260 the Full Court of the Federal Court (Spender, Gummow and Heerey JJ) said at 281 ‑ 282:

“In Imperial Chemical Industries Ltd (Clark’s) Application [1969] RPC 574 at 584, Lloyd‑Jacob J asked whether the claim was ‘plainly foreshadowed’ in the disclosure in the provisional application. In Coopers Animal Health, the Full Court also carefully drew the distinction between the claim and the disclosure, as the statute required, and as Barwick CJ had pointed out in Olin; see also the application of the distinction by Burchett J in Elconnex Pty Ltd v Gerard Industries Pty Ltd (1991) 32 FCR 491 at 505‑6, 515‑16; 105 ALR 247, affd (1993) AIPC 90‑984.
In Rhône-Poulenc (at 11) Fullagar J emphasised that disclosure without claim is enough. Hence, it is wrong to proceed as if testing for infringement and to seek to isolate in the body of the complete specification, or in the provision specification, ‘essential integers’ or ‘essential features’ of an invention disclosed therein and to ask whether they correspond with the essential integers in the claim in question; cf Coopers Animal Health Australia Ltd v Western Stock Distributors Pty Ltd (1986) 67 ALR 390 at 406, the decision at first instance. Nor would it be applying the statute to ask whether the earlier specifications fairly described the essential features of the invention disclosed in the later specification; cf Yamazaki at 93, 97. Fullagar J also pointed out that the requirement of ‘fair basing’ on matter disclosed in an earlier specification would be senseless if what was required was that the subject matter of the claim must have been actually claimed in the earlier specification; rather, there must be ‘a real and reasonably clear disclosure’. This passage was adopted and applied by Gibbs J in Hoffman‑La Roche at 119, where the claims were for chemical compounds forming part of a very large class disclosed in the basic application.”

This decision was analysed more recently in Leonardis v Sartas No 1 Pty Ltd (supra) where the Full Court of the Federal Court (Burchett, Hill and Tamberlin JJ) said that the earlier Full Court’s reference to Lloyd‑Jacob J in Imperial Chemical Industries Limited (Clark’s) Application [1969] RPC 574 whether the claim was “plainly foreshadowed” by the disclosure in the provisional application was not a synonym for fair basis or a statement of the legal test for fair basis. The Full Court said, at 40 ‑ 41, that what Lloyd‑Jacob J had said in context:

“offers no support to the proposition that the language used by Fullagar J should be qualified by a requirement of plain foreshadowing. That would be to erect an ambiguous test (depending whether the emphasis placed on a mere foreshadowing, or upon its being done plainly) as some kind of gateway to be passed through ... It is better to adhere to the statutory language, as expounded in simple terms by Fullagar J and accepted in a number of the passages we have already cited.”

I adopt and apply the principles set out in these authorities. There is, in my opinion, a real and reasonably clear disclosure that the valve is a controllable valve in the sense in which I have construed that expression in the claims.

I also reject the respondents’ contention that there is no fair basis for the claim that the fluid escapes at right angles to the lengthwise axis of the valve member. That matter is specifically referred to in the specification and further identified by reference to the path of the arrows shown in figure 1.

Conclusion

The claim for infringement is not made out as the respondents’ valve does not embody all the essential integers of the applicant’s patent. The respondents’ valve does not have a valve face which is provided with an arcuate surface and I am not satisfied that the fluid escaping from the outlet of the respondents’ valve escapes at right angles to the lengthwise axis of the valve member.

The application must be dismissed with costs. The cross‑claim for invalidity has not been made out and must be dismissed with costs.

I certify that this and the preceding thirty‑eight (38) pages are a true copy of the Reasons for Judgment herein of the Honourable Justice Goldberg

Associate:

Dated: 12 June 1998

Counsel for the Applicant: Mr G S Clarke

Solicitor for the Applicant: Garland Hawthorn Brahe

Counsel for the Second and Third Respondents: Mr G C McGowan

Solicitor for the Second and Third Respondents: Phillips Ormonde & Fitzpatrick

Date of Hearing: 11, 12, 13, 14, 15 and 16 May 1997

Date of Judgment: 12 June 1998

IN THE FEDERAL COURT OF AUSTRALIA
VICTORIA DISTRICT REGISTRY	VG 153 of 1993

BETWEEN:	JAMES JOSEPH HUTT Applicant
AND:	ENIG PTY LTD First Respondent J S MELBOURNE CONTROLS PTY LTD Second Respondent JOHN STANLEY MELBOURNE Third Respondent
JUDGE:	GOLDBERG J
DATE OF ORDER:	12 JUNE 1998
WHERE MADE:	MELBOURNE

IN THE FEDERAL COURT OF AUSTRALIA
VICTORIA DISTRICT REGISTRY	VG 153 of 1993

Counsel for the Applicant:	Mr G S Clarke
Solicitor for the Applicant:	Garland Hawthorn Brahe
Counsel for the Second and Third Respondents:	Mr G C McGowan
Solicitor for the Second and Third Respondents:	Phillips Ormonde & Fitzpatrick
Date of Hearing:	11, 12, 13, 14, 15 and 16 May 1997
Date of Judgment:	12 June 1998