Martin Engineering Co v Trison Holdings Pty Ltd
[1989] FCA 74
•14 MARCH 1989
Re: MARTIN ENGINEERING COMPANY; E.S.S. ENGINEERING SERVICES AND
SUPPLIES PTY LIMITED
And: TRISON HOLDINGS PTY LIMITED (trading as DYNA ENGINEERING
WA; GIANGREGORIO MASSAROTTO; NICARO HOLDINGS PTY LIMITED, MATFLO
ENGINEERING PTY LIMITED AND RICHARD COUPER
Nos. G 212 and G 427 of 1988
FED No. 74
Patents
COURT
IN THE FEDERAL COURT OF AUSTRALIA
NEW SOUTH WALES DISTRICT REGISTRY
GENERAL DIVISION
Burchett J.(1)
CATCHWORDS
Patents - revocation - inutility - novelty - patent for scraping mechanism to clean conveyor belts - test for utility - "useful choice" - effect of "promises" in the specification - principles of construction of claims - nature of utility asserted in specification - whether unlawfulness of taking advantage of ability to maintain conveyor while in motion, offered by the patent, prevents it being useful - combination invention - whether, in respect of novelty prior patents could be considered together because of a reference in one to others - rejection of the use of such a reference where the reference contains no suggestion that the integers should be brought together, at least a real link being requisite - meaning of "sleeve" - whether, where there is a missing integer in a prior device which it would be obvious to supply, novelty can still be denied - whether it is necessary rather that the difference between the prior device and the patent be insubstantial - tests for anticipation - obviousness - whether a device was part of "common general knowledge" - evidence of a known need and of commercial success of claimed invention.
Patents Act 1952, s.100(1)(e),(g),(h).
HEARING
SYDNEY
#DATE 14:3:1989
Counsel for the Applicants/First Mr D.K. Catterns
and Second Cross-Respondents:
Solicitors for the Applicants/First: Williams Niblett
and Second Cross-Respondents:
Counsel for the Respondents/ Mr T. Simos QC with
Cross-claimants (G.212 of 1988): Mr J.L.B. Allsop
Solicitors for the Respondents/ Phillips Fox
Cross-claimants (G.212 of 1988):
Solicitor for the third Williams Niblett
Cross-respondent:
Solicitor for the Respondents/ Mr R.T. Gregory
Cross-claimants (G.427 of 1987):
ORDER
The cross-respondents bring in short minutes of orders to reflect the decision of the court.
NOTE: Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.
JUDGE1
These are two suits for infringement of the same patent, in each of which there is a cross-claim seeking revocation of the patent on the grounds of want of utility, lack of novelty and obviousness. The course was taken of hearing first the evidence and argument in relation to these matters, postponing the other questions which arise in the suits. For the purpose of the separate questions so heard, it was ordered that the evidence in one proceeding be evidence in the other.
The patent is a convention patent, number 512902, the priority date of which is 10 January 1977. The patentee is Martin Engineering Company, an United States corporation, the first applicant, and the second applicant is the holder of an exclusive licence in respect of it. I shall refer to the patent as the Martin patent.
The evidence shows that conveyor belts used in the mining industry and elsewhere for the transport of materials require to be cleaned, generally by some form of scraping, at a point at or near the commencement of the return run of the belt after discharge of its load. Various problems are associated with this operation. The load may leave a residue which may build up on the scraper or scrapers, and on the means by which they are applied to the belt. Maintenance may be rendered more difficult by constriction of space under and in the vicinity of the belt, and particularly at the point of discharge of its load. The minimisation of loss of the productive operation of the belt during any stoppage for maintenance of scraping equipment is a consideration of some importance.
It appears that a number of devices have been adopted - from quite primitive scrapers knocked up in a mine workshop to relatively complex equipment. Patents obtained in respect of such equipment span a period of over forty years up to 1977.
The Martin patent is in respect of an invention entitled "Belt Cleaner Mounting Arrangement", being, as it is described in the abstract of the disclosure, "a track mounted conveyor belt cleaner wherein individual belt scraper blades are affixed to sleeve members which slide linearly along a support member positioned generally transverse to the direction of travel of the belt to be cleaned. The sleeves are slidably mounted on the support member such that they may freely slide from one end to the other but are fixed against either rotational or vertical movement and provide for repair or replacement of wiper blades without requiring conveyor belt shutdown."
There is in the specification a recital of the prior art, suggesting that many arrangements "have presented certain problems with respect to repair or replacement of individual blade elements." It is stated:
"Sometimes the wiper blades are carried on one end of a torsion spring. The other end of the spring is affixed to a transverse support. Such an arrangement is illustrated in U.S. Patent 3,342,312. As the wiper blades wear, periodic replacement is required. Occasionally a wiper blade becomes damaged during regular use and the individual blade must be replaced. In either of these situations the conveyor belt must be shutdown
(sic) and one of two alternatives is presented to the belt operator. If access permits, the operator may be able to disconnect the individual wiper blades from the support shaft and replace them as needed. In the majority of situations however, access to the underside of the conveyor belt is limited and the entire support shaft must be removed from the side of the conveyor housing. This is often difficult to accomplish because of limited space. The time lost for conveyor shutdown due to wiper blade replacement is a critical factor to be considered.
It is therefore an object of the present invention to provide a belt cleaner mounting arrangement which will obviate or minimise the foregoing disadvantages in a simple yet effective manner or which will at least provide the public with a useful choice."
There follows a consistory clause in the following terms:
"Accordingly the invention consists in apparatus for cleaning a conveyor belt comprising a linearly extending support member adapted to be positioned beneath the conveyor belt in use and generally transverse to the direction of the conveyor belt travel; at least one sleeve member mounted on the support member for sliding movement therealong, the sleeve member being arranged to cooperate with the support member to prevent rotation of the sleeve about the support member when mounted thereon, mounting means on the sleeve members, one or more belt cleaning elements mounted on the mounting means, and an adjusting element operable on the support shaft for bringing the belt cleaning elements into engagement or out of engagement with the conveyor belt."
The body of the specification then proceeds to describe "one preferred form of the invention". In this form, there is a support member beneath the return run of the belt adjacent to the roller at the discharge end of the belt. The support member is transverse to the direction of travel of the belt, ie parallel to the roller. It is a tubular hollow shaft with a projection forming a key beneath its lower surface along substantially its length. Upon this support member are slid a number of sleeves in the shape of tubes having a slightly larger diameter than the shaft, so as to fit over it, with a channel cut out at the bottom to enable them to slide past the key, which then prevents them revolving round the shaft. At the top of each sleeve there is provided a fixing means to enable a scraper blade to be bolted to the sleeve (or in a more complex version to enable a torsion arm bearing a scraper blade to be bolted to the sleeve). The specification states: "For purposes of illustration three such sleeve members ... are shown ... but the number will vary depending upon the width of the belt to be cleaned, the width of the scraper blades and a number of other factors." In the preferred embodiment, these sleeve members are linked for simultaneous movement along the support shaft, being designed to slide freely along it. But rotation is prevented by the key, so that when the support shaft is itself either rotated or lifted to bring the scraper blades into contact with the belt a predetermined angle of contact will be maintained.
The preferred embodiment includes, too, a flexible cable passed through the hollow centre of the support shaft and hooked at each end to the edge nearest that end of the nearest sleeve member. If the members are then connected, this facilitates adjustment of the position of the group of members relative to the conveyor belt to be cleaned.
The preferred embodiment also involves a fairly complex mechanism for raising and lowering the support shaft at each end by the use of a jacking screw.
A modified embodiment is described in which each wiper blade is carried on a torsion arm instead of being mounted directly to the sleeve.
In another modified embodiment, the support member is formed of a tubular section with a piece of angle iron welded to the top of it, and the configuration of the sleeve is altered to fit over (and round the edges of) the piece of angle iron, as an alternative to having sleeves of a circular cross-section with a keyway to fit a key attached to the support member.
The body of the specification concludes:
"Various features of the invention have been particularly shown and described in connection with the illustrated embodiments of the invention, however, it must be understood that these particular arrangements merely illustrate and that the invention is to be given its fullest interpretation within the terms of the appended claims."
The claims are the following:
"1. Apparatus for cleaning a conveyor belt comprising a linearly extending support member adapted to be positioned beneath the conveyor belt in use and generally transverse to the direction of the conveyor belt travel; at least one sleeve member mounted on the support member for sliding movement therealong, the sleeve member being arranged to cooperate with the support member to prevent rotation of the sleeve about the support member when mounted thereon, mounting means on the sleeve members, one or more belt cleaning elements mounted on the mounting means, and an adjusting element operable on the support member for bringing the belt cleaning elements into engagement or out of engagement with the conveyor belt.
2. A mounting arrangement for conveyor belt cleaners as in claim 1 including cable means connectable to at least one of said sleeve members for moving said sleeve member along said support member.
3. A mounting arrangement for conveyor belt cleaners as in claim 1 including connector means linking adjacent sleeve members for simultaneous movement along said support member.
4. A mounting arrangement for conveyor belt cleaners as in claim 2 in which said cable means is a flexible cable connected at each end thereof to a sleeve member.
5. A mounting arrangement for conveyor belt cleaners as in claim 1 including a torsion spring arm connected at one end to a belt cleaner blade and at the other end to said mounting means.
6. A mounting arrangement for conveyor belt cleaners as in claim 1 in which said means for preventing rotation of said sleeve members about said support member also prevents relative vertical movement of said sleeve with respect to said support member."
The cross-claimants' first ground of attack on the patent is the ground referred to in s.100(1)(h) of the Patents Act 1952, "that the invention, so far as claimed in any claim of the complete specification ... is not useful". The cross-claimants draw attention to the words in the complete specification: "It is therefore an object of the present invention to provide a belt cleaner mounting arrangement which will obviate or minimise the foregoing disadvantages in a simple yet effective manner or which will at least provide the public with a useful choice." The "foregoing disadvantages" are conveyor shutdown, difficulty of disconnection of individual wiper blades from the support shaft, and "in the majority of situations" limited access to the underside of the conveyor belt and necessity to remove the entire support shaft from the side of the conveyor housing, which is "often difficult to accomplish because of limited space." The ultimate disadvantage is "time lost".
The cross-applicants' first point is that, as regards one form of the prior art, a cleaner known as the Stephens-Adamson cleaner, it is, so they assert, simply incorrect to suggest that the entire support shaft would require to be removed. In the case of that cleaner, there is what is called a "cross-angle" upon which the individual cleaning elements are supported, and it is this which would have to be removed, not the support shaft. The cross-applicants argue that an invention cannot be useful by overcoming a disadvantage which does not exist. Later in these reasons, I shall examine, in connection with another argument, the operation of the Stephens-Adamson cleaner, the principle of which is described in two patents referred to as the Reiter patent and the later Sinden patent. For the present, it is sufficient to say that it would be a distortion of ordinary principles of construction to construe the language of the patent in suit by reference to distinctions drawn in the language of another patent. The draftsman of the specification of the Martin patent, when he talked about "many varied arrangements ... in the prior art for mounting conveyor belt cleaners on a support member", clearly referred to that on which the cleaning elements themselves were mounted as the "support member". It is the removal of this member which he saw as involving a difficulty, and the evidence before me confirmed that it may indeed, in practice, present a problem because of lack of space in which to work in the area where the cleaner is located. That part, the removal of which is suggested to involve that difficulty, is called, by the draftsman of the specification of the Reiter patent, a "cross-angle". It is nonetheless a "support member" or "support shaft" within the meaning of the patent in suit.
In any case, a large number of different devices existed at the priority date of the Martin patent. The statement made in the complete specification refers to the "majority of situations"; if one cleaner, out of many types in use, had already solved the problem in a different way, that would not make a second solution useless. In reality, at the priority date Stephens-Adamson cleaners were such a rarity that two highly qualified experts, one giving evidence for the applicants and one for the respondents, as well as other witnesses of great experience in the industry, had never heard of them. Even on the basis that the Stephens-Adamson cleaner does not require removal of the support shaft, unless the complete specification is to be read as limiting the utility it claims to the particular advantage in respect of the support shaft, as an advantage over all other possible cleaners, this ground of attack must fail. I do not think the language is so intractable. What is stated is that all the prior art "presented certain problems with respect to repair or replacement of individual blade elements." A particular problem instanced is the difficulty caused by limited space. This difficulty, on the evidence, may in fact exist with every form of the prior art spoken of at the hearing. In particular, the cross-angle of the Stephens-Adamson cleaner, whether or not it is properly to be described as a support shaft or support member, is necessarily of a length which would present a problem in the situation, referred to in the complete specification, of a conveyor housing to the side of which there is limited space. There was proof that a situation of that kind is common.
But the cross-claimants then say that claim one of the Martin patent refers to "at least one sleeve member mounted on the support member for sliding movement therealong". They point out that, though the body of the specification clearly enough indicates that it would normally be desirable to use a number of sleeve members, and this is the way in which in practice the device marketed by the applicants works, the claim includes a device with one sleeve. That particular form of the invention as claimed would, it is argued, involve a problem of space quite similar to that involved with the Stephens-Adamson cleaner. The argument envisages the installation of a cleaner constructed according to the physical requirements of claim one, but in complete disregard of the principle upon which the invention set out in the specification works. I have no doubt that, when the draftsman used the expression "at least one sleeve member" in claim one, he had in mind his statement in the specification: "the number (ie of sleeve members) will vary depending upon the width of the belt to be cleaned, the width of the scraper blades and a number of other factors." The recital of the prior art makes it clear that prominent among those other factors would be the amount of space available in respect of the particular conveyor belt at the location where the cleaner might be installed. Clearly enough, in the case of a narrow belt, with adequate space, a single sleeve member might be satisfactory, particularly if the length of the sleeve itself were not unnecessarily designed as co-extensive with the length of the wiper blade affixed to it.
The cross-claimants make a further point. The specification does not refer only to the difficulty of servicing the equipment; it also specifically refers to "time lost" in doing so. The cross-claimants called evidence which asserted that the Stephens-Adamson cleaner would permit replacement of wiper blades more quickly than is possible according to some embodiments of the invention in suit. It is common ground that the device marketed by the cross-respondents involves an arrangement not shown in the specification (which they claim is a workshop improvement) enabling a sleeve member to be simply slid and lifted off the support member. This is accomplished by a variation in the construction of the support member and sleeves. A piece of angle iron or flat bar is welded to a pipe, and the sleeve is made to slide on the angle iron or flat bar which terminates before the point at which the pipe is supported, so as to leave a gap fractionally longer than the length of the sleeve. An alternative way of accomplishing the same objective, with a piece of equipment built more closely in line with the preferred embodiment set out in the complete specification, would be to have the support attached to the underside of the key, referred to in the description of that embodiment, so that the sleeve would not be impeded by the attachment of the support from sliding off the end of it. It was not clear to me from the evidence whether the device has actually been constructed in this alternative way. However, Mr Law referred to it as a method of construction, and it seems clearly practicable. Another variation which has been adopted by the cross-respondents relates to the means of bringing the apparatus into engagement or out of engagement with the conveyor belt. As I have said, the preferred embodiment refers to a jacking screw. In practice, the method employed in order to bring the scraping elements into and out of contact with the belt has been by rotating the support shaft.
The question, of course, is not whether the particular version or versions of the invention in fact marketed will work; the question is whether any version constructed in accordance with claim one will work. There was no suggestion that any such embodiment of the invention would not work, if that means that it would not provide an effective belt cleaner the appropriate maintenance of which would be practicable. In other words, there was no challenge to utility in the sense that the invention is capable of making "the wheels ... go round", to use the often quoted metaphor of Maugham L.J. in The Mullard Radio Valve Company Limited v. Philco Radio and Television Corporation of Great Britain Limited (1935) 52 RPC 261 at 287. It has been said that this is what is required for immunity against attack on the ground of inutility - not that an invention is commercially practicable: ibid; Lane Fox v. Kensington and Knightsbridge Electrical Lighting Company (1892) 3 Ch 424 at 431. But the cross-claimants say that the specification promises to overcome the difficulty of the time taken to remove scraper blades from belt cleaners, particularly in confined spaces. They contend the invention, as claimed in claim one, includes apparatus which would not be useful in the required sense, because it would not do what the specification says it will do.
The argument rests on twin foundations, both of which must support it if it is to stand. One foundation is the nature of the utility asserted for the invention in the specification; the other is the construction of claim one for which the cross-claimants contend.
As regards the utility asserted by the patentee in the specification, in my opinion the argument gives an unduly narrow construction to the document. What the specification asserts is that the invention will "obviate or minimise" the disadvantages referred to "or ... at least provide the public with a useful choice." It is plain that, in some circumstances, the invention will enable those parts of the apparatus bearing scraper blades to be arranged in multiples of relatively short length so as to facilitate removal in a confined space, and that it makes possible replacement of individual blades without the unbolting of the blades themselves at the site. It may or may not require, depending upon the particular embodiment of the invention, the removal of bolts at the side of the housing of the equipment. What this means is that an alternative method is provided - on the face of it, a practical choice which a belt operator might wish to adopt in particular circumstances. As Fletcher Moulton L.J. made clear in British Liquid Air Company Ld v. British Oxygen Company Ld (1908) 25 RPC 577 at 607, (in a judgment described by Lord Loreburn when the case went on appeal to the House of Lords as "illuminat(ing) this entire subject" (26 RPC at 528)), to give "to the public a useful choice" is "all the meritorious utility requisite to support a Patent." In strictness, the pledge in the present case, expressed in the alternative, professes to do just that. So understood, it is not falsified by the evidence; and it follows that the attack on the utility of the invention fails.
I am, in any case, by no means satisfied the other foundation of the cross-claimants' argument on utility is sound. It is true that, for the purposes of utility, it is necessary to consider what on their correct construction is specified in the claims; if on their correct construction they assert a monopoly, not only in respect of something useful, but also in respect of something not useful, the patent is bad: Blanco White on Patents for Inventions, fifth edition (1983) ss.4-408 to 4-412. In Norton and Gregory Ld v. Jacobs (1937) 54 RPC 271 at 276-277 Lord Greene M.R., speaking for the Court of Appeal, held that a claim for a process which included the words "wherein there is present ... a reducing agent" could not be cut down to avoid inutility by limiting it to those processes in which there was present a reducing agent that would work. It was held not to be enough that "a skilled chemist would avoid working in part of the area which the words in their ordinary meaning are wide enough to include." But Lord Greene was not eschewing the ordinary processes of construction of a document; he was asserting that the claims have to be read in the light of their function, that is "to define with clarity the area of (the) monopoly." He emphasized: "It is illegitimate to whittle away clear words in a claim by reading into them glosses and limitations extracted from the body of the Specification whose function is in its essence different from that of the claim."
This reasoning, of course, cannot be applied where the words in the claim are not "clear words", nor does the reference to the peculiar purpose of the claims mean that they are to be construed without regard to the specification of which they form part. See Blanco White, op. cit. ss.2-101 to 2-104, and see Henriksen v. Tallon Limited (1963) RPC 329 at 335. In British Thomson-Houston Co Ld. v. Guildford Radio Stores (1937) 55 RPC 71 at 88, Luxmoore J. affirmed the necessity "to remember that the claims of a specification must be considered in the light of what an intelligent person skilled in the particular art to which they relate and desirous of making use of the invention would do"; "to introduce into every claim limitations dictated by common sense after a persual of the whole of the Specification including the claims; and ... that a claim is not to be invalidated for vagueness or ambiguity by reason of the fact that it is possible to imagine debatable territory where the advantages of the invention may not be obtained." In Welch Perrin and Company Proprietory Limited v. Worrel (1961) 106 CLR 588 at 601-602 Menzies J., as to whose decision on the point the Full Court at 622 had "no doubt", said:
"The lack of utility alleged did not go beyond the suggestion that the claims were so general that an unworkable machine could be made in conformity therewith. ... The principle that all within the scope of the claim must be useful if the claim is not to fail for inutility was invoked and reference was made to Norton and Gregory Ltd v. Jacobs and other cases which show that a claim is bad if it covers means that will not produce the desired result even if a skilful person would know which means to avoid."
After referring to a particular suggestion of a useless machine that could be constructed according to the claim, he said:
"I consider, however, that no one reading the specification would so understand it and that a very ordinary person would know what was a workable angle. What I have quoted from the Master of the Rolls (this was a reference to the Norton and Gregory case) does not mean that a specification should be construed in a way that any sensible person would appreciate would lead to unworkability when by construction it could be given a more limited meaning."
It will be noted that in this passage Menzies J. said "no one reading the specification would so understand it," thus making it plain that he regarded the specification as legitimately throwing light on the true meaning of the claim. This decision was cited by Stephen J. in Washex Machinery Corporation v. Roy Burton & Co Pty Ltd (1974) 49 ALJR 12 at 18-20, where he also distinguished the Norton and Gregory case, dismissing a suggested type of useless machine, constructed according to the claim, as one which would only be produced "by a quite purposeful adoption of such a form ... as would obviously malfunction". He commented:
"To postulate such a happening is not an appropriate mode of testing validity of a patent specification."
In my view, it is quite apparent from a reading of the whole specification in the present case how the invention enables the number of sleeves to be related to the width of the belt to be cleaned and the space available. To adapt the words of Stephen J., only by a quite purposeful selection of an inappropriately large sleeve could the result for which the cross-claimants contend be produced. Even if, in deference to the Norton and Gregory case, attention is focussed single-mindedly on the claim, the words "at least one sleeve" must direct the attention of the skilled reader to the fact that a selection has to be made of the appropriate number for the job; in other words, he is inevitably cast back to the specification which makes plain the criteria of appropriateness. In terms of Lord Greene's formulation of the principle, this is to narrow the claim by a process of construction in the light of the rest of the document of which it forms part, and not impermissibly to place a gloss upon it.
In supplementary written submissions, counsel for the cross-claimants placed reliance, in addition to the matters already discussed, on two further points: that according to some witnesses the invention required the incorporation of some kind of device, such as a pin, to prevent the sleeve members moving laterally out of their correct position by reason of variations in the tracking of the belt; and that the prospect offered by the specification of blade removal without the stopping of the belt could not be realized by reason of safety factors and the regulations governing the operation of belts in the various states of Australia.
The first point was disputed by Mr Law, who said he had seen many examples of the apparatus working without such a device. I accept his evidence. I do not doubt that the alleged difficulty would on occasion arise, but this is not sufficient to destroy the utility of an invention which would otherwise work without difficulty. Somewhat inconsistently, the cross-claimants at the same time alleged that the sleeves would be liable to resist movement on the shaft, even when removed from contact with the belt, thus reducing the time advantage in the changing of scraper blades claimed for the invention; if so, the frictional resistance when the blades are applied with some force, during operation, at an angle to the underside of the belt would inhibit lateral movement. In any case, the most unimaginative workman could devise a pin or even use a piece of timber as a stopper to prevent the suggested lateral movement. In the case of the embodiment shown in the specification of the patent which involves the use of a flexible cable, the mere tying of the slack tightly to a fixed part of the frame of the apparatus would be an adequate means of preventing lateral movement of the sleeves.
The point about the stopping of the belt does not, of course, answer the proposition that the invention offers a useful choice; the device does so whether or not it enables certain maintenance operations to be carried out without stopping the belt. Counsel for the cross-respondents also drew attention to the fact that many patents, particularly in the area of drugs, involve advantages which it is unlawful to utilize as at the priority date, and for some time thereafter; they nevertheless offer useful possibilities which may result in changes to regulations to permit those possibilities to be realized. It is unnecessary to pursue this aspect of the matter, having regard to my view that the invention in any case offers a useful choice, even if there can be no question of carrying out any maintenance while a conveyor is in operation. Part of the advantage of that choice, compared with many other cleaners used in practice, is that the exchange of slidably mounted sleeve members, complete with attached scraper blades, for elements containing worn blades, would enable a worn blade to be replaced without the removal of possibly rusted, dirt-encrusted, or otherwise stiffened blade attachments beneath the belt.
The cross-claimants also attacked the patent on the ground specified in s.100(1)(g) of the Patents Act, "that the invention, so far as claimed in any claim of the complete specification ..., was not novel in Australia on the priority date of that claim."
Reliance was placed on a number of alleged anticipations, with which I shall deal seriatim.
The first matter relied on, as revealing an anticipation, is a patent which was referred to as the later Matson patent. This patent is United States Patent No. 3,674,131, the specification of which became open to public inspection in the Australian Patent Office, Canberra, on 9 March 1973.
Counsel relied on two particular references in the specification of the later Matson patent, one under the heading "Summary of the Invention", and the other in a statement of the alleged advantages of the invention, to "axial assembly and disassembly". He said this was simply different language meaning the same thing as the reference to "at least one sleeve member mounted on the support member for sliding movement therealong" in the specification of the patent in suit, and claimed that all the other elements of claim one of the Martin patent were to be found in the later Matson patent - with the possible exception of "an adjusting element operable on the support member ... ". For the cross-respondents, on the other hand, it was pointed out that nothing in the specification suggested that the later Matson patent had anything to do with the concept embodied in the Martin patent of the sliding of sleeve members, bearing cleaning elements, into and out of position along the support shaft.
Under the heading "ABSTRACT", the invention the subject of the later Matson patent is described as:
"An improved mount for a conveyor cleaner arm featuring a split tube about a torsionally elastic torus and wherein the arm is rigidly secured to the tube, as by welding, across the split or gap so as to fix the gap dimensionally whereby the gap provides a keyway to receive a key on the exterior of the torus."
This, as a reading of the specification quickly shows, refers to a sophisticated means of elastically mounting the scraper blades. It is not concerned with the problem of ready removal of the entire mount, bearing the individual blade, from the rigid support member in a simple fashion, without going under the conveyor, which is an important aspect of the patent in suit. When the specification of the later Matson patent is studied, it becomes apparent that the references in it to axial assembly and disassembly are not references to the attachment to the support shaft at all, but to the assembly and disassembly of the complex elastic mount itself. The mount is attached to the support shaft on what are described in the specification as "brackets".
In the first preferred embodiment of the later Matson patent, the support shaft is shown as of square cross-section, and the bracket is fitted to it by an attachment which encompasses it, having the same cross-section. I do not doubt that in some contexts that attachment could be described as a sleeve. In the case of the specification of the later Matson patent, however, it is shown with a bolt going through it and the support shaft, so that it is firmly attached and cannot slide at all. There is no suggestion in the specification that it is intended to be slid into position, or out of position, at any time during the period when the cleaner is installed. To the contrary, the emphasis in the specification upon the axial assembly and disassembly of the part attached to the bracket makes it clear that the intention is to effect those operations with the bracket already in place. There is nothing to suggest that it would not be fixed prior to the installation of the support shaft, and retained at all times until after removal of the support shaft, should that event ever occur. That there is no thought of a "sleeve member mounted on the support member for sliding movement therealong" is also confirmed by a second preferred embodiment, in which the bracket could by no stretch of the imagination be described as a sleeve member. In that case, it involves a clamp gripping a tubular support shaft, to which it is immovably fixed by the tightening of two bolts, one on each side.
Counsel for the cross-claimants suggested that this second embodiment would involve "an adjusting element operable on the support member", so as to anticipate this integer also of the patent in suit. However, any adjustment achieved by varying the tangent at which the scraper is clamped to the support would be operable on the scraper mounting system, and not on the support member, which would remain fixed, whereas the invention the subject of the suit involves a means of adjustment operable on the support shaft itself (referred to in claim one as a support member). In any case, it does not seem to me that the clamp in the second preferred embodiment of the later Matson patent is an adjusting means for bringing the belt cleaning elements into engagement, or out of engagement, with the conveyor belt. It is nothing but a means for rigidly attaching the bracket to the support shaft, and it is the position of the support shaft which must determine whether the cleaning elements engage the belt. No adjusting means in respect of that engagement is referred to in the specification of the later Matson patent. In particular, the specification does not suggest that the function of the clamps in the second preferred embodiment, which it still calls "brackets", differs from that of the attachments in the first by providing a means of adjustment.
The specification of the later Matson patent commences with a section headed "BACKGROUND OF THE INVENTION". In this section, it is noted that the theretofore common method of cleaning conveyor belts involved "spring-pressed scraper blades" mounted on arms "bias(sed) ... into engagement with the belt by metallic coil springs." In that context, it is then stated:
"A representative prior U.S. Pat. is that to C.G. Matson, No. 3504786, and consider also the art cited in that patent. All of these use coil springs in one form or another and means are provided for adjusting the spring-load. These prior structures are generally satisfactory, but it has been found that they leave room for improvement in the areas of manufacture, economy, ease of assembly and disassembly, etc."
On the basis of this reference to what may be called the earlier Matson patent, and citing George C. Warner Laboratories Pty Ltd v. Chemspray Pty Ltd (1967) 37 AOJP 2513 at 2516, counsel for the cross-claimants contended that it was permissible, for the purposes of his argument on the issue of novelty, to read the later Matson patent with the earlier Matson patent, and indeed to read both with patents referred to as the Reiter patent and the earlier Sinden patent by reason of further references to them in the earlier Matson patent. The specifications of the earlier Matson patent, the earlier Sinden patent, and the Reiter patent became open to public inspection, respectively, in the Australian Patent Office, Canberra, on 3 August 1971, on 4 March 1935, and on 29 February 1968.
So far as the earlier Matson patent is concerned, counsel for the cross-claimants referred to this because it shows methods of adjustment by rotation of a support member bearing a number of scraper blades. Under this invention, the scraper blades are held in firm contact with the belt, either by the rotation of their support and the fixing of it in the appropriate position by the tightening of a nut on a bolt able to move through an arcuate slot, or by a lever one end of which is attached to the support shaft and the other to a turnbuckle, or similar mechanism for pulling the lever, so as to enable the shaft to be rotated, bringing the blades into firm contact with the belt. A more complex means is also described in this patent, involving the use of a spring-loaded fluid-pressure motor, responsive to a timing device, by which the support is intermittently rotated to bring the blades into contact with the belt and then rotated out of contact, in order to achieve intermittent scraping.
Counsel for the cross-respondents argued that it is impermissible to read several patents together, even where they contain cross-references in relation to particular issues, in order to deny novelty to a combination patent. But he also pointed out that the earlier Matson patent specification, although it involves a rotatable support shaft, makes no mention of that feature as a means of facilitating withdrawal of slidably mounted parts by first releasing their contact with the belt. Its concern is the opposite - that is to say, it is concerned with "means for applying pressure to a blade-mounting support" so that the scraper will scrape. For removal, it adopts the entirely different approach of taking out the support shaft itself. The specification says: "It is advantageous to be able to mount the supports (ie the supports bearing the arms to which scrapers are attached) for ready removal." The parts bearing the scrapers are, in the first Matson patent, "rigidly affixed to the support".
Similarly, the earlier Sinden patent (which relates to a much older device in respect of which the U.S. patent was applied for in 1932) envisages a horizontal support member with arms bearing scrapers bolted to it, this horizontal member being lifted through an arc by pivoted supports, raised by threaded screws, in order to force the scraper blades against the belt. In the same patent, an alternative is shown involving the use of a counterweight as a flexible means of applying pressure - flexibility being regarded as desirable because of inequalities in the belt surface due to wear.
The Reiter patent was relied on by the cross-claimants, both as a document referred to in the earlier Matson patent and also as in itself an anticipation of the invention in suit. The reference in the earlier Matson patent to the Reiter patent and the earlier Sinden patent is quite tangential. A feature of the earlier Matson patent is that it involves the use of scrapers on both surfaces of the conveyor belt, and not merely, as with all the other cleaners to which reference was made in the evidence, the load bearing surface. Under the heading "BACKGROUND OF THE INVENTION", the specification of the earlier Matson patent refers to the need to scrape accumulated material from belt conveyors, and states: "Several such scrapers have been patented, primarily as evidenced by such U.S. patents as (the earlier Sinden patent and the Reiter patent), but all of these operate on the principle of cleaning the under or bottom surface of the return run of the belt, because, obviously, to scrape the top surface of the upper or delivery run is merely to scrape off the material being conveyed. So far as is known, no patentee has recognized the need for scraping the inside of the belt; that is, either the underside of the delivery run or the topside of the return run."
Whatever else may be said of the Chemspray decision, and of similar statements such as that in Blanco White op. cit. s.4-107, it is not at all obvious that the decision can have any application to a reference of this kind in one specification to another, particularly in the case of a combination patent. All of the integers of a combination patent may be old (Minnesota Mining and Manufacturing Company v. Beiersdorf (Australia) Limited (1980) 144 CLR 253 at 266), the interaction of the combined integers to produce a new result constituting the invention. If some only of the integers are disclosed in one specification, a reference of the kind in question here to another specification, which contains the remaining integer or integers, no more discloses the combination than does the knowledge possessed by the expert in the area of each of the old integers. Such a reference contains no suggestion whatever that the different integers should be brought together. Indeed, the reference in the specification of the earlier Matson patent to the still earlier patents of Reiter and Sinden is simply dismissive. The logic which forbids the assembly of previously known specifications into a mosaic of the invention, in order to deny its novelty, is not less offended when those specifications are linked only as antitheses. At the least, a real link is requisite: Minnesota Mining and Manufacturing case at 292-293, 298.
The Reiter patent relates to a cleaner the manufactured version of which was the Stephens-Adamson cleaner, already mentioned, and there was evidence that a number (though perhaps not many) of these had been sold in Australia prior to the priority date. Another U.S. patent, for the earliest version of the Stephens-Adamson cleaner, was referred to as the later Sinden patent. The specification of that patent became open to public inspection in the Australian Patent Office, Canberra, on 27 February 1958. It was not suggested by counsel for any party that, for present purposes, a significant distinction should be drawn between the two patents relating to cleaners of the Stephens-Adamson type. Each involves a supporting pipe transverse to the conveyor belt, held at either end by attachment to a vertical support with a series of holes drilled in it, so as to make provision for raising and lowering the pipe. Another support, of a length at least equal to the width of the belt, rests on the supporting pipe. That other support is called, in various parts of the specification of the Reiter patent, "the supporting frame", "a support adapted to be mounted transversely of the belt to be cleaned", "the support", "an elongated support member, holder or cross-angle". It is of L-shaped cross-section, and has fixed to it a number of C-clips (catalogues with illustrations of the Stephens-Adamson cleaner show two C-clips), so that when it sits on the pipe support the two surfaces presented by its L-shaped cross-section encompass about half of the circumference of the pipe support, which the C-clips enable it to grip by partially completing that encompassment. As the specification says:
"The holder ... is mounted to rotate and to slide on the supporting pipe ... by a plurality of C-clips ... fixed to the holder ... ."
At one end of the holder there is a mechanism comprising a lever, arcuate slot, and wing nut, by means of which the scraper blade pressure may be regulated by rotating the holder on the pipe support. In the Reiter patent, the arms bearing the scraper blades are "fixedly connected to the supporting frame," that is to the holder. The specification refers to a method for "fixedly connecting one end portion to the support" by the use of mounting eyelets by which it is bolted to the support. The method of getting access to work on the scraper blades of the Stephens-Adamson cleaner for maintenance is simple, but it obviously requires space beside the conveyor belt comparable to the width of the belt itself, for the holder (with its attachments) has to be slid off the pipe support, after removal of the wing nut on the bolt in the arcuate slot which fixes the whole apparatus in position.
Counsel for the cross-claimants submitted that the later Sinden and Reiter patents, and the Stephens-Adamson cleaner to which they relate, constitute anticipations denying novelty to the patent in suit. He submitted that the holder, with its C-clips, constituted a "sleeve member mounted on the support member for sliding movement therealong", as specified in claim one of the Martin patent. I have some difficulty in so regarding it. The relevant meaning of the word "sleeve", as given in the Shorter Oxford English Dictionary (1980), is "a tube, or hollow shaft, fitting over or enclosing a rod, spindle, etc., and designed to protect or strengthen it, or to connect one part with another." Quite similar definitions are to be found in Webster's New International Dictionary (1958), The Macquarie Dictionary and the McGraw-Hill Dictionary of Scientific and Technical Terms. See also Chambers' Dictionary of Science and Technology. Certainly, the specification of the Martin patent does not use the word in a very strict sense, but a piece of angle iron with an L-shaped cross-section is not a sleeve, though resting on a pipe. I do not think it becomes a sleeve because there are disposed along its length a series of C-clips, which do partially encompass the pipe.
But, in any case, I think there is an insuperable difficulty in the way of regarding the Stephens-Adamson cleaner as an anticipation of the cross-respondents' invention. It is not enough that there be a sleeve member mounted on the support member for sliding movement therealong; it is also requisite that "the sleeve member (be) arranged to co-operate with the support member to prevent rotation of the sleeve about the support member when mounted thereon". By contrast, the Stephens-Adamson cleaner requires rotation of the holder about the pipe support as its means of achieving adjustment of the pressure exerted by the wiper blades on the belt. Both the specification of the later Sinden patent, and the specification of the Reiter patent, expressly state that the holder "is mounted to rotate and to slide on the supporting pipe". What fastens the apparatus in position, when the right position has been achieved, is not any co-operation between a sleeve and that on which it is mounted, but, as it is expressed in the specification of the later Sinden patent, "an adjusting lever fixed on one end of the cross-angle, and a wing nut cooperating with the threaded stud on one of the adjustable angle arm sets to fasten the wiper assembly in position." It does so because the wing nut applies frictional force in the area of the sides of an arcuate slot formed in the lever.
Counsel for the cross-respondents submitted that, even more fundamentally, on a true understanding of the principles upon which the two types of cleaner operate, the holder of the Stephens-Adamson cleaner is really a "support member" within the meaning of the patent in suit. It has no sleeve mounted on it, but has the arms bearing the scraper blades attached to it by bolting. I think this is in fact the correct way of looking at the matter. The two types of cleaner are at opposite poles. The cross-respondents' cleaner has a support member provided with means for bringing it into and out of adjustment with the belt, and from which the sleeves bearing the scraper blades may be removed individually for maintenance. The Stephens-Adamson cleaner also has a support member which may be adjusted by rotating it to achieve contact with the belt, but in that case the method of removal for maintenance is by removal of the entire support member with its attachments bearing the scraper blades. In the case of the Stephens-Adamson cleaner, the pipe support is really the means by which the support member is held in position beneath the conveyor belt.
If, indeed, the pipe support is regarded, as the cross-claimants' argument requires it to be, as the support member, on which the holder is to be regarded as a sleeve, then the Stephens-Adamson cleaner does not have the last integer of claim one of the Martin patent. For that integer is "an adjusting element operable on the support member for bringing the belt cleaning elements into engagement or out of engagement with the conveyor belt." Although it is true that the Stephens-Adamson cleaner involves a crude means of adjustment of the position of the support pipe by raising or lowering its attachment to its vertical supports, this is certainly not provided "for bringing the belt cleaning elements into engagement or out of engagement with the conveyor belt." Given that the Stephens-Adamson equipment is held in a suitable position beneath the conveyor belt in the way mentioned, the method by which the belt cleaning elements are brought into or out of engagement with the belt is the rotation of the holder by means of the lever arm, and the fixing of the rotated position with the wing nut. If the holder is not the support member, it is clear this is not accomplished by an adjusting element operable on the support member, but by an adjusting element operable on the holder, that is, on the cross-claimants' argument, on the sleeve member. As it is expressed in the specification of the Reiter patent, "the pressure handle (ie the lever) positions the wiper blade and springarm assemblies for proper blade pressure and other vertical adjustments."
The cross-claimants also relied on anticipation by prior use, not only in relation to the Stephens-Adamson cleaner, but also in relation to a number of other cleaners which shared one basic principle. These were the Trelleborg, Firestone, Skega and Jerry Rig cleaners. Each of these consists of a support shaft transverse to the belt, on top of which is fixed firmly a thick bar of hardened rubber, or in the case of the Trelleborg cleaner a series of shorter lengths of such bars arranged in a manner thought to provide maximum cleaning effect. In each of these cleaners, the method of fixing the rubber bar or bars to the support is by bolting. The bolts of course do not pass through the entire thickness of the rubber bar, which would result in the bolt head scoring the underside of the conveyor belt. Even if the bolt head were countersunk, the same result might ensue after a period of wear. The method adopted, in each case, is to have a T-shaped channel cut in the bottom of the rubber bar to take the head of a T-bolt, by which the bar is then bolted to its support. The bolt passes through the support, to be tightened by a nut underneath. In the case of the Trelleborg cleaner, the T-shaped channel, which is described in the specification of the Trelleborg patent as "an outwardly open undercut groove for a bolt", is bonded to the rubber bar by vulcanization. The Jerry Rig cleaner is the simplest version, since it is simply knocked up in the workshop of the company operating the conveyor, the name, as one expert witness suggested, being probably a corruption of the words "jury rig", the nautical expression for a makeshift mast or rudder. All of these cleaners use a counterweight or spring to exert the appropriate degree of force for the application of the scraper to the underside of the conveyor.
Counsel for the cross-claimants argued that each of these cleaners is an anticipation of claim one. According to his argument, the rubber bar, in the case of the Skega cleaner, or the metal insert to which the bar is vulcanized, in the case of the Trelleborg and also the Firestone and Jerry Rig cleaners, is or involves a sleeve member.
The cross-claimants' argument receives some qualified support from an expert called in their case, Mr Frost, a senior lecturer in mechanical engineering. Mr Frost described the Trelleborg cleaner as involving "an extruded aluminium T-slot mounted on a series of T-bolts on the support member so that they can to some degree be slid on and off; the T-slot being arranged with the T-bolt in such a way as to prevent rotation of the T-slot about the support member ... ." He stated of this arrangement:
"In my opinion the Trelleborg T-slot can be considered to be a generic sleeve member or is at least functionally equivalent to the sleeve member referred to in Claim 1 of the Patent."
As against that view, the cross-respondents relied on the affidavit of Professor Thomas, who added to his theoretical knowledge of engineering a vast experience in mining, including the design and use of conveyor belt installations. Professor Thomas did not regard the T-slots in the various T-bolt systems as "generic sleeve members", or as functionally equivalent to sleeve members. He stated that the bars in devices of that kind are usually fixed in position by placing T-bolts along the T-slot, dropping the bolts into the bolt holes, and then tightening the bolts from underneath by screwing on the nuts. He considered it difficult, in practice, to slide the bar along T-bolts already positioned in bolt holes because of a number of factors. In the first place, it would be necessary to lift each T-bolt head to a position in the T-slot enabling it to slide freely. Secondly, the T-bolt head would easily jam. Thirdly, an accumulation of grease, dirt and dust would be apt to set in the T-slot rendering sliding impossible. Professor Thomas's view is supported by the affidavit of a Mr Dunn, chief mechanic of the Sinter Plant of the Rod and Bar Product Division of Broken Hill Pty Limited in Newcastle. The plant handles large volumes of iron ore on conveyor belts, of which there are currently 151 in operation. Mr Dunn, in the course of the past twenty-five years, has seen a large range of conveyor belts and conveyor belt cleaners throughout Australia. He thought it might be possible to slide the T-slot of a scraper on the T-bolts, but in his opinion "this would in most instances be achieved only with a great deal of difficulty." He referred to the build-up of material along the inside of the T-slot, in the case of the Trelleborg cleaner, and the tightness of fit in the case of the Dunlop cleaner, which is a Skega cleaner. He considered it "far easier to replace the scraper blades of the T-bolt Cleaners by removing the nuts and washers from the holding T-bolts and lifting the Scraper Blade, complete with the holding T-bolts, off the support."
I accept the evidence of Professor Thomas and Mr Dunn, which seems to me to accord with the probabilities. Turning then to claim one, I do not think a T-slot of a T-slot cleaner is a "sleeve member mounted on the support member for sliding movement therealong". I think, in the case of the T-slot cleaners, the rubber bar is mounted on the support member by the use of T-bolts which fix it in position. The function of the T-slot is as a convenient means of attachment of the bolts. It is interesting to note that the brochures for the Skega cleaners, manufactured by the Dunlop company, call the T-bolts "clamps".
Furthermore, if the groove or T-slot of a T-bolt cleaner is regarded as a sleeve, it is a sleeve around the heads of the T-bolts, and co-operates with the heads of the T-bolts, not with the support member. That co-operation prevents rotation around the heads of the T-bolts, not around the support member. The cross-claimants' argument assumed that what was in question was rotation of the rubber bar about the support member. Claim one of the Martin patent is concerned with rotation of the sleeve about the support member when mounted thereon. The T-slot is neither mounted on the support member, nor does any question of rotation of it about the support member arise. It is mounted on the heads of the T-bolts which pass through the support member, and prevented from rotating by the co-operation between those heads and the groove of the T-slot.
But counsel for the cross-claimants urged me, if I rejected the argument that the T-slot of a T-slot cleaner is a sleeve, to find nevertheless that these cleaners sufficiently anticipate the invention in suit because, so he says, it is obvious to have a sleeve as an alternative to the T-slot arrangement. A similar argument was advanced in relation to the Stephens-Adamson cleaner. These arguments require some brief examination of the law in respect of novelty.
In Meyers Taylor Pty Limited v. Vicarr Industries Limited (1977) 137 CLR 228 at 235 Aickin J. said:
"The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement ... ."
(See also Minnesota Mining and Manufacturing case, supra, at 298.) Aickin J. proceeded to note that in the Meyers Taylor case "no prior object and no object according to a prior document involved or incorporated all the integers of any one of the claims and could therefore possibly constitute an infringement." This approach suggests that if a sleeve member within the meaning of claim one arranged to co-operate with the support member to prevent rotation of the sleeve about the support member when mounted thereon, or that sleeve member mounted on the support member for sliding movement therealong, is missing from an alleged anticipation, only a finding that the difference is insubstantial within the meaning of the authorities would assist the cross-claimants' case. In the Washex case (supra) at 18, Stephen J. thought there was a material difference between the patent there in suit and an earlier specification referred to as the Bochan specification. He said:
"Applying what has been said by the Court of Appeal in General Tire & Rubber Co v. Firestone Tyre & Rubber Co Ltd (1972) RPC 457, at p 486, there are in Bochan no 'clear and unmistakeable directions to do what the patentee claims to have invented'."
When the test whether the alleged anticipation would have been an infringement of the cross-respondents' patent is being applied, it is relevant to note the passage from the speech of Lord Diplock in Catnic Components Limited v. Hill and Smith Limited (1982) RPC 183 at 242-3 which was cited by Lockhart J. in Rhone-Poulenc Agrochimie SA v. UIM Chemical Services Pty Ltd (1986) 68 ALR 77 at 92-93. That passage emphasizes, amongst other things, that a variant from a requirement stated in the claim of a specification, which would have a material effect upon the way the invention worked, could not be regarded as insubstantial. As Lockhart J. said at 93:
"I agree with Wilcox J. that the pith and substance principle has a limited application and is typically applied where the alleged infringing article reproduces all integers but departs in a minor respect from the description of one of them. ... (T)his is a case where the elimination of the integer affects the way in which the invention works."
Counsel for the cross-claimants relied on Griffin v. Isaacs (1942) 12 AOJP 739, where Dixon J. at 740 referred to "the difficulty of maintaining a definite distinction between novelty and subject matter", a difficulty since lessened by the decision in the Minnesota Mining and Manufacturing case. Dixon J. went on:
"Where variations from a device previously published consist in matters which make no substantial contribution to the working of the thing or involve no ingenuity or inventive step and the merit if any of the two things, considered as inventions, is the same, it is, I think, impossible to treat the differences as giving novelty."
McTiernan J., at 740, expressed the matter with brevity; he thought the anticipation and the invention were not "substantially different". Starke J. concluded "nothing is disclosed that is not already known to or well within the range of knowledge of competent workmen in the trade ... ." Latham C.J. held that "the applicant's invention was in substance disclosed to the public by (the prior publication) and accordingly was not novel."
Griffin v. Isaacs has been the subject of critical analysis in an article by K.R. Handley Q.C. entitled "THE NO MAN'S LAND BETWEEN NOVELTY AND OBVIOUSNESS" published in the December 1986 issue of Intellectual Property Forum. The article raises questions about the decision in Windsurfing International Inc. v. Petit (1984) 2 NSWLR 196. However, so far as I am concerned, the law which binds me was laid down by the Full Court of the Federal Court in Dennison Manufacturing Company v. Monarch Marking Systems Inc. (1983) 1 IPR 431, where Griffin v. Isaacs was discussed in detail, and its effect in the light of the subsequent decision of the High Court in the Minnesota Mining and Manuacturing case explained. Fox J. at 441 said:
"It is apparent from Griffin v. Isaacs ... that complete accord between the terms of the disclosure and the claim is not necessary."
He cited the passage from the judgment of Dixon J. to which I have referred, and continued:
"This statement encompasses what are commonly called 'workshop improvements'."
At 442, he applied the principle in the following terms:
"(T)he change would only constitute an insubstantial change, a workshop improvement."
Franki J., at 452-454, came to a similar conclusion. He referred to "a development which any competent workman in the trade might have been expected to make", and agreed with the view that the integer in question in that case was at best "a mere workshop improvement." In support of his understanding of the law, he cited the classical statement of Lord Westbury in Hill v. Evans (1862) 4 De GF & J 1195 at 1199-1200 that "the information as to the alleged invention given by the prior publication must, for the purposes of practical utility, be equal to that given by the subsequent patent".
The passage from the judgment of the Court of Appeal in The General Tire & Rubber Company v. The Firestone Tyre and Rubber Company Limited (1972) RPC 457 at 486 to which Stephen J. referred in the Washex case, supra, at 18, is worth setting out in more detail for present purposes, commencing at 485. The Court of Appeal stated:
"(I)f carrying out the directions contained in the prior inventor's publication will inevitably result in something being made or done which, if the patentee's patent were valid, would constitute an infringement of the patentee's claim, this circumstance demonstrates that the patentee's claim has in fact been anticipated. ... To anticipate the patentee's claim the prior publication must contain clear and unmistakeable directions to do what the patentee claims to have invented ... . A signpost, however clear, upon the road to the patentee's invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee."
In my opinion, the differences, which I have already discussed, between the alleged anticipations and the cross-respondents' invention cannot be described as insubstantial or as workshop improvements. They affect the nature of the thing and the way in which it works. Accordingly, the attacks based on novelty in the present case fail.
I should, however, refer to a separate argument which was advanced by counsel for the cross-respondents in respect of many of the cleaners alleged to have anticipated the Martin patent. He contended that neither a counterweight nor a spring is "an adjusting element ... for bringing the belt cleaning elements into engagement or out of engagement with the conveyor belt." This, he said, is because they only operate one way, to achieve engagement. However, I think each is an adjusting element in both aspects. Clearly, it brings the scrapers into contact with the belt; but it also provides for disengagement by release of the spring or by support of the counterweight. Whether these systems are "operable on the support member" may depend on whether there is rotation of the support member, or only of the arms (with their scrapers), or corresponding parts, radially about the support member. In the latter case, there may in some circumstances be a question whether the difference is substantial.
The final ground on which the cross-claims were based is the ground (set out in s.100(1)(e) of the Patents Act) of obviousness. It was argued that the cross-respondents' sliding sleeves required no inventive step and would have been suggested by a consideration of the prior art - particularly of the Stephens-Adamson cleaner and the T-bolt cleaners.
I think it is helpful to remind myself of the fact that the invention claimed by the cross-respondents is a combination. The meaning of that, in patent law, was explained by Dixon C.J., Kitto and Windeyer JJ., in their joint judgment in Welch Perrin and Company Proprietary Limited v. Worrel (1961) 106 CLR 588 at 611, where they said:
"That is to say, what is described is a machine, the elements of which are all well known and simple mechanical integers, but combined so that they are not a mere collocation of separate parts, but interact to make up a new thing."
In such a case, it is plain from this statement of the law that no single element of a combination patent need be other than well known and simple. The inventive step is to be found in the combination of them so as to interact to produce a new result. In the Minnesota Mining and Manufacturing case, supra, at 266 Aickin J. put it as follows:
"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."
So far as the Stephens-Adamson cleaner is concerned, it is necessary to bear in mind that the specifications of the patents in respect of it are not to be regarded as part of the "common general knowledge" of those working in the field of conveyor belt cleaners in Australia. There was no such evidence in this case as would be required according to the principles laid down in the Minnesota Mining and Manufacturing case, supra at 294-295. But the cross-claimants' argument was presented on the footing that the Stephens-Adamson cleaner itself, in the form in which it had been manufactured, was part of the common general knowledge in Australia in the requisite sense. This was disputed. The evidence proved four actual manufacturing orders in respect of Stephens-Adamson cleaners over a period of about ten years prior to the priority date; but nothing was proved as to the installation of the cleaners the subject of those orders. I accept that there were difficulties with records, and that it is fair to conclude upon all the evidence that other sales, of which no detail can now be ascertained, may also have occurred, including sales over an even longer period. But the very fact that this evidence is so threadbare, though it was clearly in the interests of the cross-claimants to prove the existence in notorious locations of Stephens-Adamson cleaners, seems to me to be significant. If the details cannot now be ascertained, how can it be said that, just over ten years ago, the existence and mode of operation of these cleaners was a matter of common general knowledge? If the incontrovertible presence of information in the Patent Office was held to be insufficient in the Minnesota Mining and Manufacturing case, it is difficult to draw conclusions from the presence of an indefinite number of pieces of equipment for unknown periods in unknown circumstances at unknown locations scattered over a long period of years. For all I know, none of the cleaners delivered (accepting that a number of deliveries did occur) may have worked satisfactorily, and anything approaching common general knowledge about them may have been such as to dismiss them from consideration. They may have been so dismissed from consideration at some time prior to the priority date, if known before. There is no evidence about a single one functioning in Australia in the period immediately before the priority date, or indeed, in any specific way, at any time. Purely on a design basis, there was criticism in the evidence before me of the dependence of the whole mechanism upon a single wing nut; in the absence of actual evidence about the fate of the cleaners, it may be that their robustness was not such that any installed remained in service for long.
The other significant piece of evidence about the Stephens-Adamson cleaners was that four experts in the field, whose evidence was before me, simply knew nothing about them. In the case of Mr Dunn and Professor Thomas, the great width of their experience gives special force to this circumstance.
Taking everything into consideration, I am unable to be satisfied that the system of the Stephens-Adamson cleaner was part of the relevant common general knowledge. In fact I do not think it was. In reaching that conclusion, I have not lost sight of the fact that the hypothetical "person versed in the art" may be a "highly qualified technologist in the research department" of a manufacturing company: Johns-Manville Corporation's Patent (1967) RPC 479 at 493, per Diplock L.J.
The question remains whether the cross-respondents' patent involves an invention. In Meyers Taylor Pty Limited v. Vicarr Industries Limited (1977) 137 CLR 228 at 249 Aickin J. said:
"It is trite law that a 'scintilla of inventiveness' is sufficient and that 'no smallness or simplicity will prevent a patent being good' ... ."
There is all too easy and tempting a slope from the recognition of the simplicity of an idea to a conclusion, when someone else has already expressed it clearly, that there was nothing inventive about it.
In the present case, it is noteworthy that for many years, as is revealed by the various specifications which were placed in evidence before me, it was recognized that the time involved in dismantling cleaning equipment from under a conveyor belt created a problem requiring solution. The affidavit of Professor Thomas shows that the problem of limited access and space available for maintenance is also real. He says:
"Industrial conveyors, particularly in mines and process work, often have limited access and the side space available for maintenance may be less than the width of the conveyor."
Mr Dunn confirmed the difficulty of space with the T-bolt scrapers, which were certainly part of the relevant common general knowledge, and thought there would be a similar difficulty with the Stephens-Adamson cleaner on the basis of the material about it which was shown to him. He stated that the cross-respondents' cleaners at the Broken Hill Pty Limited sinter plant do enable separate sleeve members to be slid on and off individually, and he expressed the opinion "that this could be done safely without shutting down the conveyor belt". Of course, as I have noted previously, there are regulations at present which may forbid this. I have assumed for the purposes of this judgment that they do forbid it, though there may be a question as to whether working on the cleaner is the same thing as working on the conveyor belt. Mr Dunn was unaware of any other conveyor belt system which "has been available in Australia to meet a need to minimise shutdown time for the purposes of conveyor belt cleaner blade replacement when there is restricted access to the conveyor belt." Professor Thomas stated directly, and I accept, that:
"(T)here was the need in 1977 to minimise the time taken for conveyor belt blade cleaner replacement and a problem of restricted access to the underside of the conveyor belt and no solution was offered until the development of the Martin TRAC-MOUNT System as described in the Martin patent."
I prefer the evidence of Mr Law, supported by Mr Dunn, as to the practical effectiveness of the Martin Trac-mount cleaners in solving these problems, to the contrary evidence, which I did not find convincing, proffered on behalf of the cross-claimants.
I also accept the evidence of Mr Law to the effect that the second cross-respondent's market share was perhaps ten percent several years ago, and has gone up significantly to "a much larger share of the market." He said that in the coal industry, where a few years ago the industry was "very depleted so new products or new plants were not being started, ... our main sales were replacement of existing belt cleaners, the other makes of existing belt cleaners."
In the Minnesota Mining and Manufacturing case, supra, at 297-298 Aickin J. referred to evidence of a known need at the priority date, and evidence that when introduced into the market the product "met that need, and had substantial commercial success," as "well recognized indications of inventiveness though they are not in themselves decisive." In that case, "they contribute(d) to the conclusion that there was an inventive step." Aickin J. strengthened that conclusion by placing some reliance on the fact that "there was nothing in common general knowledge which pointed to this solution to the known problem which awaited solution." On the evidence, I think the same reasoning applies here. I think counsel for the cross-respondents is right when he argues that all the previous systems tackled the problem of maintenance, either by having methods of affixing the scrapers which enabled them to be unbolted or similarly removed in situ under the conveyor, or by requiring the removal of an entire support shaft so that repairs could more conveniently be carried out away from the conveyor. Most of the types of cleaners referred to in the evidence have already been discussed. One I have not mentioned is at present the most widely used in Australia. It is the Belle Banne cleaner, in which scraper blades are attached to "elastomeric" cushions bolted to a flange of a support shaft. This system illustrates Professor Thomas's comment about the unsolved problem of access. The invention the subject of the Martin patent consisted of an ingenious, if uncomplicated, combination which enabled individual arms bearing scrapers to be removed separately, whilst leaving the support shaft in place. That solution involved an extremely simple but effective means of holding the arms bearing the scraper blades in position without bolts, so that they could easily be slid out again as required.
Applying the law as it is laid down in the authorities, and particularly in the two judgments of Aickin J. to which I have referred, I think the ingenious arrangement in the present case, simple though it appears in hindsight, was not in the relevant sense obvious, but inventive. I should still be of that opinion even if I had held the Stephens-Adamson cleaner was part of the common general knowledge of skilled persons in the field; there are fundamental differences between that cleaner and the Martin patent.
It was not argued that the claims were not fairly based.
For these reasons, the issues raised in respect of the
cross-claims as preliminary questions should be answered in favour of the cross-respondents. I direct that they bring in appropriate short minutes to reflect this decision. Upon the bringing in of the short minutes, I shall hear the parties as to the appropriate orders to be made in respect of costs.
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