Daido Metal Company Ltd v Gould Inc

[1984] APO 23

In the Matter of the Patents Act 1952

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In the Matter of Application No. 509526 for a Patent by DAIDO METAL COMPANY LTD.

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In the Matter of Opposition thereto by GOULD INC.

DECISION OF A SUPERVISING EXAMINER OF PATENTS:
        Patent application No. 509526 (15940/76) was lodged on 15 July, 1976 as a Convention application claiming priority from Japanese application No. 96325/75, filed 8 August, 1975.  Acceptance of the application was advertised in the Official Journal on 15 May, 1980.  On 13 November, 1980 Gould Inc. lodged a Notice of Opposition under section 59 of the Patents Act.  Service of evidence was completed on 6 June 1983.
        The matter was heard in Melbourne on 15 February, 1984; Daido Metal Company Ltd. (the applicant) was represented by Mr. G. Pryor, patent attorney, of Davies & Collison and Gould Inc. (the opponent) by Mr. M. Royal, patent attorney, of Phillips, Ormonde & Fitzpatrick.
The Specification
        The specification in suit is entitled "MULTI‑LAYER BEARING MATERIAL AND METHOD OF MAKING SAME".  The opening paragraph of the specification is as follows:

"The present invention relates to a multi‑layer bearing material and method for manufacturing the same, and more particularly to a composite material for bearings and method for manufacturing the same using a powder metallurgical technique.

Multi‑layer materials according to the present invention are useful for a variety of applications where a sliding relative motion occurs, e.g. as bearings, bushes, shoes, sliding plates, friction materials and sliding members for electricity collectors.  For convenience, such multi‑layer materials are referred to herein simply as multi‑layer bearing materials."

The specification asserts that the present invention lies in a "variety of improvements of the conventional composite materials for bearings". The prior art acknowledged in the specification consists of the following published patent specifications: Japanese patent publication Nos. 21122/65, 45445/74, 9056/64, 20330/64, US patent Nos. 2185567 and 3094415.  These publications are said to relate to composite materials manufactured by a powder metallurgy technique.
        The methods disclosed in Japanese patent publications Nos. 21122/65 and 45445/74 are said to have the following drawbacks:

(a)During metal‑powder rolling, cracking takes place around the end or edge of the powder loaded plate, resulting in a reduced yield rate of the final products.

(b)Due to the technique employed, in which two or three layers are formed during the process of rolling powders, such a problem as thickness control of the layer of powder to be supplied is often encountered.  This technique is, therefore, more complicated in respect of manufacturing process and requires a higher manufacturing cost than that of the method of laying and distributing metal powder directly on a steel plate.

(c)When an alloy plate is rolled together with a steel plate to be bonded therewith, it fails to be bonded with the steel plate, unless it is elongated by more than 40% of the original length.  If a powder of soft metal such as lead or the like is employed, it stretches out like a yarn without being bonded with the steel plate.  Therefore, the products manufactured in this way are liable to fatigue failure due to stress concentration when in use. 

With respect to the techniques disclosed in the last four patents mentioned above the following drawbacks are recognized.

(d)Because metal powder is distributed in a single layer and is rolled at an elevated temperature, soft metal such as lead or the like tends to concentrate in a boundary adjacent to the steel plate, causing poor adhesion.

(e)Powder of soft metal e.g. lead, extends similar to yarn during rolling at an elevated temperature.  The products manufactured according to this technique tend to fatigue easily due to stress concentration.

(f)As it is required to heat the raw material to an elevated temperature while maintaining it still in a powder state, the material should be maintained in an non‑oxidizing or reducing atmosphere so that no oxidation takes place.  This makes the manufacturing process complicated and expensive.

It will be noted that drawbacks (d), (e) and (f) relate in some way to the elevated temperatures used in these prior art methods.  The specification states that the present invention alleviates such drawbacks.
        A first consistory statement relating to the multi‑layer bearing material is then given.  It corresponds substantially with claim 1, which reads as follows:

"1.A multi‑layer bearing material comprising a backing plate of steel or plated steel and on the backing plate a first layer and a second layer of sintered metal powder, these layers being made from metal powders and/or pre‑alloyed metal powders laid one upon another, cold rolled to compact the powders and effect cold bonding in and between the layers and to the backing plate, and then sintered at an elevated temperature to enhance the bonding, the first layer being made from aluminium or aluminium with at least one additive in the form of a discrete ingredient or pre‑alloyed with said aluminium, said additive being selected from the group comprising solid lubricants and strengthening material, the second layer being made from aluminium with from 2 to 40 percent by weight of at least one solid lubricant additive in the form of a discrete ingredient or pre‑alloyed with said aluminium, the percentage by weight of the additive in said second layer being more than that of the solid lubricant additive, if any, in the first layer, and wherein said additives are substantially uniformly dispersed in both said first layer and said second layer in the form of small partly extended polygonal grains."

A second consistory statement relating to the method of manufacturing the bearing material is then given which corresponds to claim 6 which reads as follows:

"6.A method of manufacturing a multi‑layer bearing material which comprises the following steps in the sequence set forth:

(a)preparing a surface of a backing plate of steel or plated steel to make the surface suitable for adherence of a coating thereto;

(b)preparing a first powder and a second powder, the first powder comprising aluminium or aluminium with at least one additive in the form of a discrete ingredient or pre‑alloyed with said aluminium, said additive being selected from the group comprising solid lubricants and strengthening materials, said second powder comprising aluminium with from 2 to 40 percent by weight of at least one solid lubricant additive in the form of a discrete ingredient or pre‑alloyed with said aluminium, the percentage by weight of the additive in the second powder being more than that of the solid lubricant additive, if any, in the first powder;

(c)laying and distributing by gravity the first powder as a first layer on the prepared surface of the backing plate;

(d)laying and distributing by gravity the second powder as a second layer over the first layer;

(d)passing the backing plate and the two layers of powder loosely laid thereon to a cold rolling mill so as to compact the powders until the average density of each of the layers exceeds 90 percent of the theoretical density thereof and to effect cold bonding in and between the layers and to the backing plate; and

(f)sintering the rolled and compacted multi‑layer material at a temperature range from 280 to 520oC.

The following are given by the description as advantages of the invention:

"(1)Very high bond strength is obtainable, because metal powder having good adhesion to steel plate is employed for the first layer (boundary or intermediate layer).

(2)Placing of metal powder and initial rolling are carried out at an ambient temperature.  There is no rolling of a wroght (sic) alloy plate to bond it to steel plate as is required in the manufacture of some prior art multi‑layer bearing materials.  Accordingly, if a powdered low melting point metal such as lead is used as a powder lubricant this is not elongated like yarn but is distributed in the form of small polygonal grains throughout the rolled surface, affording excellent fatigue strength.

(3)Because no specific process for manufacturing rolled metal powder plate is involved and, moreover, no heating to a rage of elevated temperature is required for rolling metal powder to be bonded to steel plate, it is unnecessary to provide complicated and expensive instruments and equipment for control of the atmosphere as well as for the production line.  This results in low manufacturing cost.

(4)As no malfunction such as end or edge cracking during powder‑rolling occurs, a high yield rate of final products is expected.

(5)The closer to the bearing surface of the product, the more lubricating additive is contained therein.  This enables the product to have both excellent strength and surface properties."

I think that it is clear from this statement of advantages that the temperature at which initial rolling is carried out is an important element of the invention.  Thus as the initial rolling is carried out at "ambient temperature" elongation of low melting point metals such as lead is avoided.  Instead, the powdered low melting point metal, if used, is distributed in the form of "small polygonal grains" throughout the rolled surface affording "excellent fatigue strength".  It will be seen that claim 1 refers to the distribution of solid lubricant additive in the form of "small partly extended polygonal grains" whereas method claim 6 is silent in this regard.
        The invention is then described in detail with reference to a number of drawings.  The embodiment shows a multi‑step process.  Briefly, a coiled steel packing strip is uncoiled and degreased.  The steel strip is then passed under a wire brush which prepares the surface to be bonded.  Metal powder forming the first layer (boundary or intermediate layer) is laid and distributed by gravity on the steel strip.  Then a second metal powder layer is laid on the first layer.  The steel strip, having on it the two metal powder layers, is then fed between the gap of the rolls of a rolling mill and the metal powder loaded steel strip is subjected to rolling down until the average density of the distributed metal powder exceeds 90% of the theoretical density of the metal powder concerned.  The description states that: "this cold rolling also bonds the layer to the steel strip".  There is no indication in this part of the description of any heating step prior to the rolling step.  After this "cold rolling" the composite strip passes through a sintering furnace where it is sintered during its passage through the furnace.  A number of subsequent treatments of this sintered strip is then described.
        The specification tells the reader that the invention is not restricted to the described embodiments and to illustrate this, several variants employable in the various steps of the process are given.  Among these is the following passage occurring on page 12:

"At the rolling mill 8, cold rolling is conducted at low temperature, but by cold rolling is meant any rolling work to be conducted in a temperature range from room temperature to the recrystallization temperature of aluminium, that is, at the highest 260oC.  Normally rolling is carried out at room temperature, but if there is difficulty of metallizing, a higher temperature up to 260oC is applied during rolling.  It can be noted, however, that this way of rolling allows soft metal e.g. lead to readily elongate (this by no means damages the utility of the material) and on the other hand, promotes slow oxidation of the material to some extent.  This requires some consideration, for instance, whether the rolling work should be carried out in a controlled atmosphere."

Thus we are told that the "cold rolling" operation may be carried out at temperatures above ambient temperature.  It is further indicated that rolling at the higher temperatures "allows soft metal e.g. lead to readily elongate".  And then comes the rather surprising statement that "this by no means damages the utility of the material".  This is in direct conflict with previous statements made in relation to the advantages of the present invention over the prior art.  Furthermore it conflicts with a later statement made in relation to the bearing material of the invention at page 23, namely:

"It will be seen in the photo (of a specimen according to Japanese patent application No. 21122/65) that the components of metal of low melting point is extended like yarn.  On the contrary to the material of the prior art, the material according to this invention has no fibrous extensions of the component of low melting point, but a great many grains of polygonal sharp‑pointed shape scattered uniformly through the matrix ..."

I will return to this apparent inconsistency later in the decision.
        Having described the method of the invention with reference to the figures, the same is done for the multi‑layer bearing material; again possible variants are described.  For example it is made clear that the solid lubricant incorporated in the bearing material may be, amongst others, mica, plastics, metallic soaps, glass fibre or carbon fibre.
        The specification ends with 22 claims, claims 1 to 5 being product claims and claims 6 to 19 being method claims.  Claim 21 is a "product‑by‑
method" claim while claims 20 and 22 are, respectively, a method claim and a product claim, each with particular reference to the drawings.
Grounds of Opposition and Evidence
        The Notice of Opposition lists all the grounds available under s.59(1) however the evidence presented and the submissions made at the hearing show that the opponent relies mainly on the grounds of non‑compliance with s.40, prior publication, obviousness and lack of inventive step, and want of novelty.
        The evidence‑in‑support consists of two principal declarations, one by Brendon Aston Parker and one by Ross Owen Kirkham and five supporting declarations containing evidence relating to the publication dates of material exhibited by Dr. Parker.  Dr. Parker's first declaration has 12 exhibits which are listed below:

BAP1  The specification in suit.

BAP2     P.E. Evans, G.C. Smith: "The Rolling of Strip from Metal Powders", Sheet metal Industries 32, 589, Aug. 1955.

BAP3  S. Storcheim: "Metal Powder Rolling ‑ A New Fabrication Technique", Met. Prog. 70, 120, (1956).

BAP4  J.D. Shaw, W.V. Knopp: "Current Developments in the Rolling of Both Ferrous and Non‑ferrous Powders", Prog. Powder Met. 1, 33, (1957).

BAP5  D.K. Worn: "The Continuous Production of Strip from Metal Powder", Sheet Metal Industries 35, 615, Aug. 1958.

BAP6  G.M. Sturgeon: "Metal Strip from Powder" Chaps. 2‑3, Mills & Boon Ltd., (1972).

BAP7  T.S. Daugherty: "Direct Roll Compacting Sheet From Particles", Powder Met. 2, 2, 343, (1968).

BAP8  J.C. Gould et al, U.S. 2815567.

BAP9  V. Gallatin et al, U.S. 3094415.

BAP 10M.W. Toaz, U.S. 3812563.

BAP 11Gould Inc., AU 486154.

BAP 12Extracts from the International Patent classification 1974 (Second Ed.).

The evidence‑in‑answer consists of two statutory declarations, one by John Howard Hensler and one by Sanae Mori, the actual inventor of the present invention.
        The evidence‑in‑reply consists of two declarations by Dr. Parker and a number of declarations relating to publication dates and availability of certain documents.
        Dr. Parker is a highly qualified metallurgist who appears to have practiced his profession in Australia since 1967.  He is currently a senior lecturer at an Australian university and all his previous employment has been of an academic nature, except for five years as a pre‑graduate trainee and two years as a visiting research scientist with Alcan International Research Laboratories in Britain.  In the latter post he was concerned with the structural properties of aluminium alloys, but there is no evidence that he has had any direct experience, in Australia, of the manufacture of bearing materials produced by powder metallurgy techniques.
        Like Dr. Parker, Mr. Hensler is an academically well qualified metallurgist and currently a senior lecturer in metallurgy at Royal Melbourne Institute of Technology.  Before joining that Institute, he worked as a research officer at the Institute of Materials Research in the University of Melbourne, and before that in the same capacity at Rylands Brothers (Australia) Pty. Ltd.  The only indication in the evidence that any of this work related to powder metallurgy or to bearing materials is contained in the following state‑
ment made in his declaration:

"the project I undertook while on the staff of the University of Melbourne involved me with a very wide range of metallurgical materials and methods for producing them, include (sic) the powder metallurgy process, metal working processes (including rolling) and materials for bearings."

It appears to me that neither Dr. Parker nor Mr. Hensler can strictly be regarded as the skilled addressees of the specification in suit.  They have not been shown to have had experience in the making of bearing materials or to have any particular expertise in powder metallurgical techniques.  However they have established that they are qualified to make comment on metallurgical techniques and terms in general.
Non‑Compliance with Section 40
        The opponent contends that the specification does not comply with s.40 in a number of respects.  First in relation to claim 1 and the corresponding consistory statement it was submitted that the spatial relationship between the two powder layers and the backing strip is not clearly defined.  Thus, asserts Dr. Parker in his first declaration, while he understands the method defined in claim 6 as specifying that the first layer is between the backing plate and the second layer, he considers the converse or even a side‑by‑side relationship between the layers is possible in the product.  However I find this to be a strained construction of claim 1.  The claim refers to "a backing plate of steel or plated steel and on the backing plate a first layer and a second layer".  The natural meaning of "first layer" taken in the context of the claim as a whole, is that it is the layer adjacent the backing plate.  The claim also indicates that the "metal powders and/or pre‑alloyed metal powders (are) laid one upon another".  Thus the reference to the "second layer" must be the layer superimposed on the "first layer" and is therefore not consistent with the further contention made by the opponent that the claim comprehends side‑by‑side relationship.
        The opponent also points to what it considers to be a discrepancy between, on the one hand, the fact that the first layer does not necessarily contain an additive, and on the other the proviso that "said additives are substantially uniformly dispersed in both said first layer and said second layer in the form of small partly extended polygonal grains" (emphasis added).  I do not agree with this contention.  I read the proviso as requiring that the additive present in the second layer must be "uniformly dispersed ..." and the additive in the first layer, if present in that layer, is also "uniformly dispersed ...".  The construction contended by the opponent is not purposive.
        The opponent further finds difficulty with the phrase "small partly extended polygonal grains".  Dr. Parker in his first declaration states:

"I find no indication as to how the additive can be in the form of grains when the additive is pre‑alloyed and in solid solution with said aluminium (as distinct from additive in the form of discrete ingredient).  I also find I am in doubt as to the meaning to be given to the term "polygonal" in the statement as to the method (sic), particularly when I note from page 12 lines 2 and 3 that the additive can be carbon fibre, mica or soap."

The description itself, at page 6, refers to the phrase "small partly extended polygonal grains" in relation to "powdered low melting point metal such as lead".  The evidence‑in‑answer does not directly deal with this point.  However the applicant's Mr. Mori states in his declaration:

"An object of this invention resides in rendering the additive metals to exist not in the form of long elongated grains, but rather in the form of small grains or short, elongated polygonal grains, thus it becomes indispensable to compact the powders by cold rolling (C.P.R.B.) without their being subjected to any prior heating step before rolling."

The Mori declaration also includes examples of the invention but again none of these show the presence of polygonal grains of an additive which is alloyed in quantities which produce an homogeneous alloy or which is a soap or a fibre.  It is not clear from a reading of the specification as a whole whether it is a requirement of the invention that the additives, irrespective of their nature, are to be in the form of "small partly extended polygonal grains" or that it only applies to the case where low melting point metals are used as additives.  I consider that claim 1 and the corresponding part of the description are unclear in this respect.
        Yet another matter raised by the opponent concerns the terms "cold rolling" and "cold rolled".  Claim 1 refers to "cold rolled to compact the powders and effect cold bonding ..." and claim 6 refers to "passing the backing layers of powder loosely laid thereon to a cold rolling mill so as to compact the powders ...".  The term "cold rolling" is used in the description in relation to embodiments of the invention and at page 12 it is said:

"At the rolling mill 8, cold rolling is conducted at low temperature, but by cold rolling is meant any rolling work to be conducted in a temperature range from room temperature to the recrystallisation temperature of Aluminium, that is, at its highest 260oC.  Normally rolling is carried out at room temperature, but if there is difficulty of metallizing, a higher temperature up to 260oC is applied during rolling."

It was submitted on behalf of the opponent that these terms have no accepted meaning in the art of powder metallurgy.  That being so the opponent submits, recourse must be had to the "definition" supplied by the specification itself at page 12 as quoted above.  However it is submitted, on the basis of the evidence of the opponent's witness Dr. Parker, that this definition is ambiguous.  Dr. Parker states in paragraph 9 of his first declaration:

"Indeed, I understand from page 12, lines 7 to 21 of specification 509,526 that "cold rolling" means any rolling work to be conducted in a temperature range from room temperature to the recrystallization temperature of aluminium, that is, at the highest 260oC.  However, to my knowledge the recrystallization temperature of aluminium can range from ambient to in excess of 260oC and for some aluminium alloys to as high as about 400oC."

Further, it was asserted that the recrystallisation temperature requires the time to be specified and also varies with the degree of prior cold working.  Thus says the opponent, not only is the "definition" given at page 12 unclear, but the lack of clarity is imported into the claims through having to rely on that unclear "definition".
        In the alternative, the opponent submits that if the claims can be construed without recourse to the ambiguous definition the term "cold rolling" should be regarded as representing a process which should more correctly describe a "cold pressing by roll compacting".
        Mr. Pryor, on behalf of the applicant, contended that the terms "cold rolled" and "cold rolling" do have a clear meaning and that that clear meaning should not be supplanted by a different meaning imported from the body of the specification.
        The applicant's witness, Mr. Hensler, says that he understands the terms "cold working", "hot working", "recrystallisation" and "recrystallisation temperature" to have well defined meanings in metallurgy.  He cites the definitions of these terms given in the "Metals Handbook" 8th Edition, published by the American Society of Metals, Volume 1 at pages 9, 20 and 30 as reflecting his understanding of the meanings of these terms as at the priority date.  These definitions are given below:

"(a)"cold working" ‑ Deforming metal plastically at a temperature lower than the recrystallization temperature.

(b)"hot working" ‑ Deforming metal plastically at such a temperature and rate that strain hardening does not occur.

(c)"recrystallization" ‑ The formation of a new strain free grain structure from that existing in cold worked metal.

(d)"recrystallization temperature" ‑ The approximate minimum temperature at which complete recrystallization of a cold worked metal occurs within a specified time."

Mr. Hensler further declares that he understands the terms "hot rolling" and "cold rolling" to be specific operations in which "hot working" and "cold working" respectively take place.
        On the other hand, the opponent's witness, Dr. Parker, disputes the appropriateness of these definitions to the actual terms used in the claims.  Dr. Parker in his first declaration, does not indicate any difficulties with the meaning of "cold rolled" simpliciter, indeed at paragraph 26 he states: "... that it was known in the art in Australia as at 8th August, 1975 that cold rolling and hot rolling are alternatives available ... Indeed it is understood by me to be common ground between the disclosure of each Exhibits BAP II to BAP VI that metal powder can be cold rolled to effect compaction".  In his second declaration he states that it is his understanding that the "Metals Handbook" provides no more than simple explanations of the terms, and not well defined meanings.  He notes that the terms are defined for the purpose of readers in many branches in the metalworking industry and technology, rather than specialists in the fields to which the respective terms pertain.  He notes that the "Handbook" denotes all those definitions having specific relevance to powder metallurgy by the italicized abbreviation "powder met".  He observes that none of the definitions referred to by Mr. Hensler has that abbreviation and that he does not understand those terms as having specific reference in the art of powder metallurgy.
        Dr. Parker sets out his understanding of the terms used in the specification, at paragraph 32 of his second declaration:

"At page 4, lines 14 to 18, and Claim 1, lines 5 to 9, specification 509,526 refers to "cold rolled to compact the powders and effect cold bonding", and specifies subsequent sintering.  I understand these quoted passages to be completely in accord with the definitions of the powder metallurgical terms "cold pressing" and "roll compacting" at pages 9 and 31 of Exhibit BAP XIII, namely forming a compact at a temperature low enough to avoid sintering by the progressive use of a rolling mill.

............................................................

It is thus apparent to me that "cold rolling" to which reference is made at line 8, page 12 of specification 509,526 is a poorly expressed wording but clearly denotes use of a rolling mill to "cold roll to compact" (page 4) or "so as to compact the powders" (page 5), thereby indicating what is known in the art of powder metallurgy as "cold pressing" by "roll compacting".  On this basis, the expression "any rolling work" at line 9, page 12 of specification is not understood by me as denoting "cold rolling" in the sense suggested in paragraph 9(ii) of the Hensler Declaration, but rather as indicating any roll compacting operation.  Moreover, the term "cold rolling" as explained in paragraph 7, page 12 of specification 509,526 is indicated as being in a temperature range up to what is understood by me to be a completely unambiguous alleged upper limit."

I think that it is clear from the evidence of Dr. Parker and Mr. Hensler that the use of the terms "cold rolled" and "cold rolling" in the claims do not limit the rolling step to one performed at ambient temperature only.  Mr. Hensler understands "cold rolling" to be the specific operation in which "cold working" takes place.  If this is taken to be the meaning of the term then the operation of "cold rolling" would be performed such that the metal deforms plastically at a temperature lower than the recrystallisation temperature.  It would seem that the cold working involved is the cold working of the metal powder particles.  Dr. Parker on the other hand understands "cold rolled to compact powders and effect cold bonding" to be in accord with the definition of the powder metallurgical terms "cold pressing" and "roll compacting", namely "forming a compact at a temperature low enough to avoid sintering by the progressive use of a rolling mill".  Now, if I refer to the article "The Rolling of Strip from Metal Powders" published in the journal "Sheet Metal Industries" of August 1955 Volume 32, pages 589 to 590, (Exhibit BAP II), asserted by Dr. Parker in his first declaration as forming part of common general knowledge in the art, I find that in relation to the process of sintering it states (page 589, first column):

"The sintering temperature is generally above the recrystall‑

isation temperature of the metal compact, and always below the melting point of the major constituent."

Thus it would seem that even with Dr. Parker's understanding of the terms in question, the recrystallisation temperature is a parameter to be considered.
        I have come to the conclusion that the terms "cold rolled" and "cold rolling" mean that the rolling step is carried out at a temperature below the recrystallisation temperature of the metal powder particles used.  Lack of precise definition in the claims is not fatal to their validity so long as they provide a workable standard suitable to the intended use (British Thomson‑
Houston Co. Ltd. v. Corona Lampworks Ltd. (1922) 39 RPC 49). The upper temperature is determined by the nature of the particles themselves. As to the statement appearing at page 12 of the specification concerning "cold rolling" there is no indication in that statement or elsewhere that it seeks to act as a dictionary for that term. The statement relates to the embodiment. The natural meaning of the statement is that it understands the maximum recrystallisation temperature to be, at its highest, 260oC. I do not see it as limiting the effect of the term as used in the claims.
        It is also to the point that claim 1 further requires that the additives are substantially uniformly dispersed in the layers".  Insofar as this feature relates to the low melting metal lubricant additives, it also limits the temperature at which the rolling step may be carried out.  Thus the cold rolling operation must be carried out at a temperature such that the grains of low metal point metal lubricants present in the layer(s), are distributed in the form of small, partly extended polygonal grains.
        Two further section 40 objections were raised by the opponent.  First, in relation to the percentage of lubricant in the inner and outer layers of the bearing material, it was argued that while the percentage of lubricant in the outer (or bearing) layer is specified as 2% to 40%, the amount in the inner (or bonding) layer is specified, when present, only as being less than that in the bearing layer.  It was submitted that claim 1 thus encompasses material with, say, 40% lubricant in the outer layer and 39% in the inner layer.  Mr. Royal contended that this is contrary to one of the concepts on which the invention is predicated, namely the presence of an inner layer selected to overcome the poor adhesion to the backing material of a layer rich in lubricant.  Accordingly, he submitted, claim 1 does not define the invention as the claim must be referable to the invention (Olin Corp. v. Super Cartridge Co. Pty. Ltd. 51 ALR 52). However, it seems to me that what is being said is that the claim includes embodiments which do not achieve the promise of the invention (without providing evidence of this), an argument relating to the utility of the claimed invention, a ground not open to the opponent at this stage.
        Second, in relation to claim 8, it was submitted that there is a conflict between this claim where it reads: "... intermetallic compounds, boron nitride, graphite" and the description where it reads: "...intermetallic compounds, boron, nitride, graphite ...".  I think that the skilled addressee would immediately see that there has been an error made in the description in the positioning of the comma, and what is intended would be readily apparent to such a person.
        I have already mentioned the contradictory statements made in the description in relation to the requirement that low melting point metals be present in the cold rolled material in the form of "small partly extended polygonal grains".  It will be seen that claim 6 does not include this feature. The applicant's witness, Mr. Mori, the actual inventor of the present invention sees the object of his invention in the following way (paragraph 2.2.1 of his declaration):

"An object of this invention resides in rendering the additive metals to exist not in the form of long elongated grains, but rather in the form of small grains or short, elongated polygonal grains, thus it becomes indispensable to compact the powder by cold rolling (C.P.R.B.) without their being subjected to any prior heating step before rolling."

It seems to me, from a reading of the specification as a whole, that the requirement in relation to the additive being in the form of "small partly extended polygonal grains", is an essential feature of the invention and that claim 6 is consequently not fairly based.
        A further feature which appears to me to be essential to the invention is that the cold roll step is carried out such that the metal powders are compacted until the average density of each of the layers exceeds 90% of the theoretical density thereof.  The present invention is described as a combination of elements and steps, it is difficult to see how the objectives of the invention can be achieved without compaction of the powder metal layers to this degree.  I believe Mr. Mori's comment in paragraph 2.2.3 of his declaration is consistent with this conclusion.  He states:

"On the other hand, powder mixtures are compacted by cold rolling in accordance with the C.P.R.B. method of my invention until the densities thereof are raised to more than 90% of theoretical density ..."

As claim 1 does not include this feature I consider it not to be fairly based and hence does not comply with section 40.
Prior Publication and Want of Novelty
        On the ground of prior publication and want of novelty the opponent relied on three patent specifications, US Patent Serial No. 3812563, available in the Patent Office Library on 5 March, 1975; Australian Patent No. 486154 published on 15 May, 1975 and a Japanese patent specification.
        Before considering these prior documents in detail it is helpful to consider the nature of an objection of prior publication.  The approach to determining whether or not there is prior publication is conveniently set out in General Tire & Rubber Company v. Firestone Tyre & Rubber Co. Ltd. (1972) RPC 457 where the Court of Appeal, at pages 485 and 486, said:

"In the present case we are not concerned with anticipation by earlier use of the patentee's device but with anticipation by prior publication: that is to say, it is contended that the plaintiffs' invention as claimed in their patent was at the priority date of their claim something which was known in the United Kingdom by reason of prior publications.  To determine whether a patentee's claim has been anticipated by an earlier publication it is necessary to compare the earlier publication with the patentee's claim.  The earlier public‑

ation must, for this purpose, be interpreted as at the date of its publication, having regard to the relevant surrounding circumstances which then existed, and without regard to subsequent events.  The patentee's claim must similarly be construed as at its own date of publication having regard to the relevant surrounding circumstances then existing.  If the earlier publication, so construed, discloses the same device as the device which the patentee by his claim, so construed, asserts that he has invented, the patentee's claim has been anticipated, but not otherwise.  In such circumstances the patentee is not the true and first inventor of the device and his claimed invention is not new within the terms of section 32(1)(e).

The earlier publication and the patentee's claim must each be construed as they would be at the respective dates by a reader skilled in the art to which they relate having regard to the state of knowledge in such art at the relevant date.  The construction of these documents is a function of the court, being a matter of law, but, since documents of this nature are almost certain to contain technical material, the court must, by evidence, be put in the position of a person of the kind to whom the document is addressed, that is to say, a person skilled in the relevant art at the relevant date.  If the art is one having a highly developed technology, the notional skilled reader to whom the document is addressed may not be a single person but a team, whose combined skills would normally be employed in that art in interpreting and carrying into effect instructions such as those which are contained in the document to be construed.  We have already described the composite entity deemed to constitute the notional skilled addressee.

When the prior inventor's publication and the patentee's claim have respectively been construed by the court in the light of all properly admissible evidence as to technical matters, the meaning of words and expressions used in the art and so forth, the question whether the patentee's claim is new for the purposes of section 32(1)(e) falls to be decided as a question of fact.  If the prior inventor's publication contains a clear description of, or clear instructions to do or make, something that would infringe the patentee's claim if carried out after the grant of the patentee's patent, the patentee's claim will have been shown to lack the necessary novelty, that is to say, it will have been anticipated.  The prior inventor, however, and the patentee may have approached the same device from different starting points and may for this reason, or it may be for other reasons, having so described their devices that it cannot be immediately discerned from a reading of the language which they have respectively used that they have discovered in truth the same device; but if carrying out the directions 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.

If, on the other hand, the prior publication contains a direction which is capable of being carried out in a manner which would infringe the patentee's claim, but would be at least as likely to be carried out in a way which would not do so, the patentee's claim will not have been anticipated, although it may fail on the ground of obviousness. To anticipate the patentee's claim the prior publication must contain clear and unmistakeable directions to do what the patentee claims to have invented; Flour Oxidizing Co. Ltd. v. Carr & Co. Ltd. ((1908) 25 RPC 428 at 457, line 34, approved in B.T.H. Co. Ltd. v. Metropolitan Vickers Electrical Co. Ltd. (1928) 45 RPC 1 at 24, line 1). 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."

With these principles in mind I turn to the first citation, US Patent No. 3812563 entitled "Method of Forming a Composite Bearing Structure" by Milton W. Toaz which I will refer to as the "Toaz patent".  The specification sets out the background of the invention as follows:

"One technique which is commonly used to form composite bearing materials is to cast the bearing layer or material directly onto the surface of the supporting steel substrate.  Another technique which is used extensively to form such an article is to first powder roll particulate bearing material into sheet form, then sinter the so‑formed sheet and subsequently affix the sintered sheet of bearing material to the substrate proper by conventional cladding methods.

While these techniques result in usable composite bearing materials, they each suffer from certain inherent disadvantages. For example, the casting technique requires special expensive melting and casting equipment, while the cladding method requires expensive and complex hopper feed devices, rolling mills and sintering apparatus.  In addition, these processes are also hampered by the fact they employ a heating step or treat‑

ment which often adversely affects the metallurgical properties of the bearing material and/or the substrate on which it is deposited.

The instant invention overcomes certain of these limitations by providing a simplified means of bonding a bearing material to a metallic substrate without adversely affecting the metallurgical properties of the bearing material or the metallic substrate."

A summary of the invention then follows:

"Very briefly, the present invention relates to a method of adherently bonding a bearing material to a metallic substrate without adversely affecting the metallurgical properties of the bearing material or the substrate proper.  More specifically, it concerns a method of adherently bonding a bearing material to a metallic substrate which comprises the steps of treating the surface of the metallic substrate primarily to remove any undesirable foreign substances therefrom, depositing a layer of metallic bonding material on at least a portion of the surface of the treated substrate, covering at least a portion of the deposited bonding material with a layer of bearing material, heating the so‑coated substrate to a temperature which is sufficient to activate both the bonding and bearing materials, and concurrently densifying the bonding and bearing materials to near theoretical density while reducing the thickness of the substrate to thereby cause the bearing material to become adherently bonded to the metallic substrate."

The Toaz specification then goes on to indicate that in the preferred embodiment the substrate is fabricated from metal, preferably steel.  It says that the steel substrate is cleaned to remove undesirable foreign substances and includes a degreasing operation.  To this treated substrate a layer of bonding material is applied.  It states that the bonding material employed depends to a great extent on the particular bearing material to be used.  For example if the bearing material to be utilised is a copper base alloy, it is preferred to use copper or copper alloy as the bonding material.  Likewise, if the bearing material is to be an aluminium base alloy, then it is preferred to use aluminium or an aluminium alloy as the bonding material.  The bonding material is said to be preferably in the form of moderately fine powder.
        The specification then indicates that the substrate having the bonding and bearing materials position thereon is then subjected to a thermal treatment which causes both the bonding and bearing materials to become activated.  As to this activation it states: "That is, the bonding and bearing materials are heated to a temperature which improves particle ductility and is sufficient to cause oxide film which may be present on the particles thereof to be broken up by subsequent mechanical work procedures".  As to the particular temperatures the document states:

"The specific temperature required for activation depends, in the main, on the chemical composition of the bonding and bearing materials.  For example, when an aluminum base alloy is utilized as the bearing material and the bonding material is aluminum or an aluminum base alloy it is usual to accomplish activation by heating to a temperature ranging from about 450oF to about 950o, with a temperature of about 950oF being preferred.  Whereas, when a copper base alloy is employed as the bearing material and copper or a copper base alloy is utilized as the bonding material it is usual to accomplish activation by heating to a temperature ranging from about 600oF to about 1,000oF, with a temperature of about 850oF being preferred.  The exact activation temperature depends on, basically, the chemical and physical properties of the specific heating and bonding materials utilized and the requirements of the finished stock.  For example, it is often desired to activate the bonding and bearing materials at a temperature which is high enough to cause activation and at the same time heat treat the metallic substrate.

It should be noted here that activation is preferrably accomplished by heating in an inert atmosphere.  In one embodiment of the invention, activation is accomplished by heating the substrate having the bonding and bearing materials thereon in a furnace which utilizes a flowing nitrogen atmosphere to insure that these materials are not oxidized.  In this instance, a furnace was used which was contoured at one end to closely fit the rolls of a rolling mill.  The so‑covered substrate was held in the furnace for a sufficient period of time to insure that temperature equilibrium was achieved."

The temperature range specified for aluminium or an aluminium based alloy as the bonding material, 450oF to 950oF, converts to 232oC and 510oC respectively.
        After this activation step the substrate having the bonding and bearing materials deposited thereon is "directly" moved from the furnace into a conventional two‑high upright rolling mill.  In the rolling mill, densification of both the bonding and bearing material is achieved in such a manner that both layers of material exhibit an apparent density which is essentially equal to the typical wrought density of the respective material.  The steel substrate is also reduced in thickness by up to 30% and an adherent bonding takes place between the three layers.  It is said that:

"this type of adherent bonding does not occur when the bonding and bearing materials are not activated as herein described."

Two examples are given, the most relevant being Example 1 in which an 18 inch long strip of low carbon steel was degreased and sanded and layered first with aluminium powder and then with a powdered aluminium alloy containing 87.5% Aluminium, 8% Lead, 4% Silicon and 0.5% Copper.  The whole was heated to 950oF (510oC) for 10 minutes in nitrogen and then rolled to essentially the typical wrought density.  No sintering step is described.  The document points out that the invention is not limited to short strips but is adaptable to the continuous production of long lengths, and that while it is preferred to use copper or aluminium as the bonding layer, alloys of these metals may also be used.  It is said later in the specification that when alloy of aluminium and silicon is used the preferred activation temperature is 650oF to 900oF.  It is also said that instead of aluminium/lead alloy as the bearing material aluminium/cadmium or aluminium/tin may also be used.
        I now turn to the question of whether the present claimed invention has been prior published by the Toaz patent.  The Toaz patent relates to a method of adherently bonding a layer of bearing material to a metallic substrate.  The substrate having the bearing material and the bonding material thereon is said to be heated to a "temperature sufficient to activate both the bonding material and the bearing material by softening said materials and thereby increasing the ductility of said materials whereby oxide film on said activated material is broken up by subsequent mechanical treatment".  The temperature required for activation is said to depend in the main on the chemical composition of the bonding and bearing materials.  In relation to cases where an aluminium base alloy is used as the bearing material and the bonding material is aluminium or an aluminium base alloy it is said to be "usual to accomplish activation by heating to a temperature 450oF (232oC) to about 950oF (510oC), with a temperature of about 950oF (510oC) being preferred".  The sole example relating to the use of aluminium given is activated to a temperature of 510oC.  In the case of an alloy of aluminium and silicon an activation temperature of 650oF (343oC) to 900oF (482oC) is suggested.  From my reading of the Toaz patent, the temperature at which the rolling of the backing strip and the two powder metal layers insofar as the process relates to aluminium is carried out at a temperature range of 232oC to 510oC.  The preferred activation temperature is in the upper part of the range. However Dr. Parker submits that although the Toaz patent does not specifically refer to a temperature below 450oF, he understands it to necessitate a temperature only slightly above ambient temperature.  I can find no basis for Dr. Parker's assertions.  The document not only specifies heating of the materials before compacting, it suggests a range of temperatures well above ambient temperature and gives a preferred temperature at the top of this range. Dr. Parker's interpretation appears to be one based on hindsight and a construction that goes against the direction the document leads the reader.
        Thus, in relation to the temperature at which compaction of the packing strip and the powdered metal layers takes place, the citation teaches a temperature sufficient for "activation" and in the range 232oC to 510oC in respect of aluminium.  Present claim 1 specifies that the metal powders and/or pre‑alloyed metal powders, laid one upon the other, are "cold rolled to compact the powders and effect cold bonding ...".  I have already interpreted these terms as not limiting the rolling step to one carried out at ambient temperature.  According to the present specification the recrystallisation temperature is specified as up to 260oC, although, as I have already stated, the claims are not necessarily limited to this upper temperature.  There is thus an overlap as far as the temperature of rolling is concerned insofar as claim 1 includes a rolling step carried out at 232oC and above.
        The Toaz patent refers to the use of aluminium base alloy as the bearing material and aluminium or aluminium base alloy as the bonding material. The sole example relating to the use of aluminium specifies the bonding layer as aluminium powder and the bearing layer as an alloy of 8 percent lead, about 4 percent silicon and about 0.5 percent copper.  There is no mention in the US patent of the use of aluminium and a low melting point metal as discrete ingredients.  It is clear that any performance of this example would not be an infringement of present claim 1, if that claim were part of a granted patent.  The temperature at which it specifies the roll compaction to be carried out, 950oF (510oC), would clearly be understood by those skilled in the art to be a temperature at which sintering would occur and clearly would not be regarded as a cold roll reduction.
        Present claim 1 requires, amongst other things, that the additives be dispersed in the form of "small partly extended polygonal grains".  According to the present specification this feature insofar as it relates to low melting point metal additives is obtained by avoiding temperatures close to the melting point of the additives where the low melting point metals are caused to be flattened and elongated when the metal powder backing plate composite is rolled.  The Toaz patent is silent on this aspect.  Mr. Royal asserted that if the applicant wished to distinguish his invention on the basis of a particular microstructure he must show that the prior invention could never produce that structure.  However this submission does not accord with the principles set forth in the General Tire case (supra) in relation to a case of prior publication in a document.  It may be that by following the directions given in the Toaz patent, at the bottom of the temperature range suggested, something having the structure specified in present claim 1 will be achieved (I have no evidence before me which shows that it will).  However there are a number of parameters involved in the rolling operation, including the temperature and the rolling pressure and I could not say, on the evidence before me, that such a microstructure would inevitably be produced.
The Toaz patent is concerned with a composite bearing structure comprising a continuous steel substrate having an adherent layer of bonding material affixed thereto with a continuous layer of bearing material being bonded to the surface of the bonding layer. It is stated in that patent that this type of adherent bonding does not occur where the bonding and bearing materials are not activated as herein described. Thus the "activation" temperature is not only concerned with heating the bearing and bonding materials to a temperature which improves ductility and is sufficient to cause oxide film present to be broken up by subsequent mechanical working procedures but is also concerned with adherent bonding of the various layers to each other. The Toaz patent states that the preferred temperatures are at the top of the suggested range. If however the addressee were to carry the Toaz process out at temperatures at the bottom of the range it would seem to me, based on the evidence filed in this opposition, that increased rolling pressure would have to be employed to achieve adequate bonding and this could have an effect on the grain structure of those metal lubricants that may be present. On the evidence before me, I cannot say that it has been established with the degree of certainty required at this stage of life of a patent application, that there has been prior publication of the invention defined in claim 1. It has not been shown that the Toaz patent contains clear and unmistakable directions to produce the invention defined in claim 1 and that by carrying out those directions it would inevitably result in something that would be made or done or would constitute an infringement of claim 1, if a patent were granted on this application : General Tyre v. Firestone (supra); Beecham Groups Limited's Application (1980) RPC 261; Meyers Taylor v. Viccar In 13 ALJ 605. It is not clear that on carrying out the instructions of the Toaz patent, a bearing composite material having the lubricant additives in the form of "small partly extended polygonal grains" would inevitably be produced.
        With present claim 6 however there is a different situation.  Claim 6 does not specify the shape of the lubricant additives.  As will be apparent from my previous discussion concerning the disclosure of the Toaz patent, that document clearly discloses step (a) of claim 6.  As to paragraph (b) of the claim, it specifies that the first powder can be aluminium and the second powder being aluminium with 2 to 40 percent by weight of at least one solid lubricant which may be pre‑alloyed with the aluminium.  The Toaz patent discloses the use of aluminium powder as the bonding layer (first layer) and an alloy of aluminium and 8% lead.  The amount of lead present is thus within the range 2 to 40 percent specified in claim 6 and since the first layer is aluminium and the second layer is an aluminium alloy containing 8% lead, it fulfills the requirement that the second layer contains more additive (lead) than that in the first layer.
        On the subject of the degree of densification required by paragraph (e) of claim 6, the Toaz document speaks of densifying both the bonding and bearing layers in such a manner that both layers of material exhibit an apparent density which is "essentially equal to the typical wrought density of the respective material".  Dr. Parker's understanding of terms such as "near theoretical density", "essentially equal to the typical wrought density", "nearly equal to wrought density", which occur in the Toaz patent, do not differ in practical significance from an "average density exceeding 90% of the theoretical density" as used in the present specification.  The applicant's witnesses, Mr. Hensler and Mr. Mori do not refute this understanding.
        The Toaz patent also states that "if desired, the resultant composite structure can be sintered".  The temperature range specified in present claim 6, for the sintering step is 280 to 520oC.  Dr. Parker states in his declaration in support that "I consider feature (f) of claim 6 to be disclosed by each of the exhibits BAP 10 and BAP 11, reference to temperature limits for the sintering specified in each Exhibit being unnecessary in view of knowledge based on standard practice in the art".  The applicant's declarants do not counter this statement.
        That being the case, it would appear that the Toaz patent prior publishes and renders not novel present claim 6 insofar as that claim includes a rolling operation carried out above 232oC and the use of a powdered aluminium alloy in the second layer.
        The second piece of prior art relied on is Australian Patent 486154 (BAP 11) in the name of the opponent.  It is a Convention application based on the US patent application which corresponds to the Toaz patent.  The disclosure of the Australian patent is essentially equivalent to that of the Toaz patent and consequently I make a similar finding in relation to prior publication and novelty.
        I now turn to the final prior art document relied on by the opponent for the purpose of proving prior publication and want of novelty of the present claimed invention, Japanese patent Publication No. 13058/1961.  This public‑
ation was available in the Patent Office Library on 17 June, 1965.  Reference to this document was first made in the opponent's evidence‑in‑reply.  Understandably Mr. Pryor, on behalf of the opponent, objected to this piece of evidence as not being proper evidence‑in‑reply, as it had not been raised in either evidence‑in‑support or evidence‑in‑answer.  Mr. Royal submitted that should I rule this evidence inadmissable he would seek to make an application to adduce it as further evidence.  However in the end I find that I do not have to decide the matter of admissability because even when I consider the Japanese document I find that it neither prior publishes nor renders not novel the present claimed invention, and further with respect to obviousness, I do not believe that it can be considered under that ground, a point I will discuss later.
        The Japanese specification is of course in the Japanese language, however it is clear that it is the case that the content of the document was public knowledge before the priority date of the present claims (British Woven Plastic Products Ltd. & Others v. British Rope Ltd. (1970) FSR 47). The subject of the Japanese specification is summarised by its principal claim the text of which reads:

"A process for manufacturing a bearing steel sheet by bonding a sintered copper alloy having a high lead content with a steel sheet comprising the steps of:

preparing a two‑layer compressed powder material of a flat board shape which comprises an upper layer and a lower layer;

said upper layer being formed of a bearing alloy powder mainly consisting of lead 15‑70%, tin of 1‑10% and copper of 84‑20% and further containing silver below 5%, nickel below 3%, titanium below 1%, manganese below 1% and other suitable auxiliary components having a good influence on bearing performance as required or being formed of a mixed metal powder containing said component metal powders;

said lower layer being formed of an alloy powder free of lead mainly consisting of tin of 3‑10% and copper of 97‑90% and further containing at least one material selected from the group consisting of zinc, silver, nickel, phosphorus and other suitable metals capable of easily providing a strong bonding or being formed of a mixed metal powder containing said component metals;

compressing to form a flat board shape and superposing the lower layer surface on the steel sheet, or first placing the steel sheet in a frame and putting said two‑layer compressed powder material on the steel sheet in such a manner to allow said lower layer not containing lead to contact with said steel sheet having above it the copper alloy with high lead content to form a laminate and compressing said laminate as required; and

heating said laminate in a neutral or reducing atmosphere to carry out sintering of said powder and bonding of said powder material with said steel sheet to form an integral bearing sheet material."

The Japanese specification does not refer to the use of aluminium or aluminium alloy powder for the bearing layer.  However Mr. Royal drew my attention to the judgement of the High Court in Acme Bedsteads Co. Ltd. v. Newlands Bros Ltd. (1937) 58 CLR 689, which he submitted supported the proposition that it is permissable to add to the disclosure of the Japanese document, the common knowledge that, as far as roll compacting is concerned, aluminium and copper behave similarly. He submitted that, interchangeability of copper and aluminium was common general knowledge at the relevant date, this being evident from the disclosures of exhibits BAP 2 to BAP 6.
        I do not believe that the evidence establishes that copper and aluminium behave similarly as far as roll compaction is concerned, let alone that such is common general knowledge in the art.  Furthermore, the Japanese specification does not refer to the rolling of the backing plate, bonding layer and bearing layer.  Rather compaction is said to be achieved by pressing the composite, for example, by the use of an oil hydraulic press.  I think that it is clear from the evidence that the means by which the compaction is achieved determines the properties of the end product.  Thus different considerations would be involved in a roll compaction process as compared to a compaction achieved by pressing.  For the above reasons I do not consider that Japanese specification 13058/61 constitutes a prior publication of the present claims, nor do I consider that the disclosure of that document is such that it renders the present claimed invention not novel.
Obviousness and Lack of Inventive Step
        Dr. Parker, the opponent's declarant, put forward exhibits BAP 2 to BAP 12 as evidence of the common general knowledge in the art at the priority date of the present claims.  Mr. Hensler, the applicant's declarant, comments as follows:

"That at the request of the attorneys for the applicant, I read the Statutory Declaration by Brendon Aston Parker and exhibits II to XII attached to the Statutory Declaration by Brendon Aston Parker.

That prior to the request referred to in clause 4 hereof I had not read any of exhibits II to VII but believe that the information in these exhibits can properly be regarded as general metallurgical knowledge prior to August 8, 1975 which I am advised is the priority date of the claims of specific‑

ation No. 509,526.

That prior to the request referred to in clause 4 hereof I had not read either of the patent specifications identified as exhibits VIII and IX, and I was not aware of the inform‑

ation contained in those exhibits from other sources.  However, I believe that the information in the exhibits would probably have been known to a specialist in the field of powder metallurgy as applied to bearing technology prior to the priority date."

It appears to me that Mr. Hensler agrees that exhibits BAP 2 to BAP 9 formed part of the common general knowledge.  As I have already said, neither Dr. Parker nor Mr. Hensler have established themselves to be men skilled in the art of powder metallurgy, however their knowledge of metallurgy generally seems to me to qualify them to make observations on the state of the knowledge in the art, albeit, possibly not from first hand experience.  Theirs is the only evidence before me on the subject.  Mr. Pryor sought to distance his client's case from some of the admissions made by Mr. Hensler as to the state of common general knowledge by suggesting that "general knowledge" was not synonymous with "common general knowledge", and that in any case an admission by one of the applicant's witnesses is not an admission by the applicant.  In support of the latter point Mr. Pryor quoted from Phipson, "On Evidence" whilst Mr. Royal responded by referring to Terrel, 13th Edition (pages 416‑418).  It would seem that in relation to evidence before a court of law, a party is not irrevocably committed by unfavourable evidence by one of its witnesses ‑ the party is at liberty to contradict it by calling other evidence without prejudice to his continued reliance on other portions of the witnesses' evidence ‑ the applicant in this case has not done this however.
        The evidence includes a number of patent specifications ‑ Exhibits BAP 8 to BAP 11 and the Japanese patent application referred to above.  Mr. Hensler indicated that he had not read BAP 8 and BAP 9 and was not aware of the information contained in those exhibits from other sources, however, he indicates that he believes "that the information contained in those exhibits would probably be known to specialists in the field of powder bearing technology prior to the priority date".  As to the other patent exhibits Mr. Hensler disputes the allegation that they formed part of the common general knowledge.
        The role of  patent specifications in the determination of obviousness is discussed in the Judgement of the High Court in Minnesota Mining and Manufacturing Co. and another v. Beiersdorf (Australia) Ltd. (1976‑1978) 144 CLR 253. It was said in that case that for such documents to be relied on in determining the question of obviousness, it must be established that they formed part of common general knowledge in Australia before the priority date.
        The nature of "common general knowledge" is discussed in the General Tire case (supra):

"The common general knowledge imputed to such an addressee must, of course, be carefully distinguished from what in patent law is regarded as public knowledge. This distinction is well explained in Halsbury's Laws of England, Vol. 29, para. 63. As regards patent specifications it is the somewhat artificial (see per Lord Reid in the Technograph case (1971) FSR 188 at 193) concept of patent law that each and every specification, of the last 50 years, however unlikely to be looked at and in whatever language written, is part of the relevant public knowledge if it is resting anywhere in the shelves of the patent Office. On the other hand, common general knowledge is a different concept derived from a commonsense approach to the practical question of what would in fact be known to an appropriately skilled addressee ‑ the sort of man, good at his job, that could be found in real life.

The two classes of documents which call for consideration in relation to common general knowledge in the instant case were individual patent specifications and "widely read public‑

ations".

As to the former, it is clear that individual patent specific‑

ations and their contents do not normally form part of the relevant common general knowledge, though there may be specifications which are so well known amongst those versed in the art that upon evidence of that state of affairs they form part of such knowledge, and also there may occasionally be particular industries (such as that of colour photography) in which the evidence may show that all specifications form part of the relevant knowledge."

The opponent has not established that Exhibits 10 and 11 were specifications well known to those versed in the art before the priority date. Furthermore I think it is clear that the Japanese patent specification could not be regarded as forming part of the common general knowledge at the relevant date.  Not only was it in a foreign language but it was also apparently not discovered by the opponent until the evidence‑in‑reply was being prepared.  There is no evidence that the Japanese specification was widely read by those skilled in the art.
        The applicant's witness has conceded that the information contained in exhibits BAP 1 to BAP 7 formed part of common general knowledge prior to the priority date.  Mr. Hensler has also conceded the exhibits BAP 8 and BAP 9 were probably known in the art before the priority date.  These documents appear to show that the following was known in the art before the priority date:

.Metal powders in general could be consolidated into sheet or strip by roll compaction either at room temperature or higher to form a green strip which must then be sintered.  It was known that a randomly oriented fine grain structure resulted.

.It was possible to control the porosity to obtain oil‑retaining bearings.

.While most studies had been done on copper, nickel and ferrous metals, aluminium or aluminium alloys could also be roll compacted.  For these, room temperature roll capacity has been described.  It was believed that it was "absolutely necessary" to hot roll green strips of aluminium before sintering (see exhibit BAP 3).

.Bimetal strips could be obtained in three ways:

(a)roll bonding two preformed green strips;

(b)preforming one green strip and roll bonding a second powder onto it;

(c)roll compacting two superimposed layers of powder.

.A base metal could be given a protective layer or decorative coating (cladding) by roll compacting onto it a layer of powder.

.The stringering of uranium dioxide observed when a convention‑

ally prepared Uranium dioxide/Aluminium powder mixture was cold worked could be avoided if the composition was formed by roll compacting the powders (in relation to core materials for fuel elements).

Exhibit BAP 8 described the preparation of a bearing material by placing a powder mixture of aluminium plus up to 15% of lead or tin, or up to 10% cadmium, or mixtures thereof, on to a steel backing strip and roll compacting at a preferred temperature of 800oF to 1000oF (426oC to 537oC).  An upper temperature of 1100oF being set by the onset of undesirable chemical reaction between aluminium and iron.  It is said that the use of temperatures lower than the minimum temperature results in having to use excessive roll pressures in order to establish an adequate bond between the backing plate and establish an adequate bond between the backing plate and the sintered surface layer.  The exhibit discusses the problems of the prior art, which it seeks to overcome, in the following terms:

"A variety of metals and metallic alloys are used in the surface layer in bearings of the type referred to above.  Aluminum is recognized as a superior bearing metal and is frequently used in this capacity.  Also, other metals such as lead, tin, and cadmium sometimes are alloyed either individually or collectively with aluminum to produce a superior bearing metal.  The usual procedure is to alloy the additive metals with the aluminum and then bond the alloy metal on the steel backing member by one of the various well‑

known methods.  However, this procedure is subject to the disadvantage that only certain amounts of the desired additive metals are miscible with molten aluminum.  For example, lead cannot be alloyed with molten aluminum in amounts greater than about 0.2%, and cadmium cannot be alloyed with molten aluminum in amounts greater than about 4.0% without undue segregation.  While tin is miscible with molten aluminum in any proportion, upon freezing or solidify‑

ing the tin will segregate undesirably when present in amounts greater than approximately 7.0%.  As a result, the practical art has been limited to the amounts specified above in alloying lead, tin, and cadmium with aluminum in the manufacture of bearings."

It is stated that the limits on the amount of additive metals in the process of the process disclosed in the exhibit are determined by the problem of "significant loss by exudation of the low melting point metal during roll reduction".  It also states that: "exudation of the low melting point constituent during hot roll reduction appears to set the maximum allowable amount of the low melting point metal that can be incorporated in the surface alloy composition".  This is the reason for the limits on the amount of low melting point metal disclosed in relation to the process disclosed in this exhibit.
        The disclosure of BAP 9 is similar to that of BAP 8 except that it relates exclusively to the use of tin as the additive metal.  The amount of tin present is present in an amount of 7 to 30%, the elemental tin content being less than 15% with the balance being pre‑alloyed with a portion of the aluminium.  The rolling is performed in the range 700oF (371.1oC) to 1100oF (593.3oC) in a reducing atmosphere which is said to be essential. Again the amounts of elemental tin present are said to be limited by the fact that if it exceeds 15% exudation occurs during the hot rolling operation that is used in the process.
        There is nothing in Exhibits BAP 8 or BAP 9 to suggest either the use of a double layer of powder or of roll compaction by cold rolling.  The opponent pointed out that roll compaction of two layers of metal powder was known.  However, there is no evidence that roll compaction of two layers of metal powder and a metal substrate was common general knowledge at the priority date.
        As to the temperature at which compaction is undertaken, it was the opponent's contention that cold roll compacting and hot roll compacting were available alternatives.  Thus in exhibit BAP 5 it is said:

"The actual compacting operation may be carried out hot or cold.  Hot compacting although offering many advantages, necessitates complex atmosphere control, and to date cold compacting has received most attention."

According to Mr. Royal, because Exhibit BAP 8 did not specify any lower temperature limit, but merely that there was an inverse relationship between the temperature and pressure necessary, then it would be obvious to a man skilled in the art to try using a temperature lower than that described in the hope of avoiding the disadvantages of an energy consuming heating step and the need for an inert atmosphere and yet still achieve good bending provided the pressure was sufficient to fracture the oxide film.  Dr. Parker says in paragraph 21 of Parker 2:

"I understand Exhibit BAP 8 as envisaging and allowing for temperature down to the lower limit for sintering to be possible, albeit with the need for increasing roll pressure."

To establish obviousness, the argument continues, it is only necessary to show that something was clearly worth trying, the authority for this being Washex Machinery Corp. and Another v. Roy Burton Co. Pty. Ltd. 49 ALJR 12. So, contends the opponent, it would be worth trying the process disclosed in BAP 8 at lower temperatures down to the lower limit for sintering in order to obtain the known advantages thereby accruing. Although Dr. Parker does not put a figure on "lower limit for sintering", I note that in paragraph 30 of Dr. Parker's first declaration he evidently regards the range 280oC to 520oC as standard sintering conditions in the art. I therefore understand the opponent's argument to be this: that despite being told in exhibit BAP 8 that the preferred lower limit is 426oC, a man skilled in the art would consider it worth trying to use temperatures down to 280oC. Again I find Dr. Parker's contention to be one based on ex post facto analysis.  It appears to me that the teaching of the higher temperatures in the document is an active discouragement to the use of lower temperatures
        I consider that the opponent has failed to establish its ground of obviousness and lack of inventive step.  The most striking deficiency in its case is the failure to establish that it was common general knowledge to roll compact two powder metal layers to a metal substrate for the purpose of bearing material, let alone that performing the compaction by cold rolling was common knowledge.  It has dissected the claimed invention into its various parts and steps and attempted to establish each of those elements was common general knowledge.  It is an argument based on ex‑post facto analysis.
Decision
        I have found that the specification does not comply with section 40 in certain respects and that claim 6 has been prior published.  I am satisfied that there is patentable subject matter disclosed in the specification and for this reason I allow the applicant 60 days from the date of this decision in which to lodge amendments to my satisfaction.  I award costs against the applicant.

(P.A. KILBORN)