Sly v United Development Corporation Pty Ltd

High Court of Australia|1962-07-01|Before: Menzies J

High Court of Australia Menzies J. Sly v United Development Corporation Pty Ltd [1962] HCA 16

ORDER Appeal allowed with costs. Allow the amendment of claim 3 by inserting the words not substantially exceeding 6 and between the words permeability and such.

Menzies J. delivered the following written judgment: -

The Deputy Commissioner refused the application on the ground of the ambiguity of the claim in question, relying on that ambiguity as a reason per se for refusing leave and alternatively relying upon it as the reason for his not being able to decide one way or the other whether the amendment was forbidden by s. 78.

Claim 3, as it appears in the specification, is as follows: "Apparatus for conveying finely-divided substantially dry material consisting of a porous medium having a surface along which the material is adapted to flow when aerated, which porous medium has a permeability such that the pressure required to pass 4 c.f.m./sq. ft. of gas through the porous medium is greater than the pressure required to pass 4 c.f.m./sq. ft. of gas through a substantially 2 inch bed of said material measured while said material is unaerated and while supported on said porous medium."

The amendment sought is to insert the words "not substantially exceeding 6 and" between the words "permeability" and "such".

The course of reasoning followed by the Deputy Commissioner was to point out that the invention related to apparatus and methods for conveying finely-divided materials (e.g. cement or flour) by aerating them in a closed or open channel by passing air or some other gas into them through a porous medium forming the bottom of the channel, and that it is the essence of the invention that the porous medium should have "relatively high resistance to gas flow", to quote from the consistory clause of the specification. Attention was then directed to the circumstance that two meanings of this term were indicated in the specification - (1) that the permeability of the porous medium according to a standard provided does not substantially exceed 6 and (2) that the substance has a resistance to the passage of gas therethrough such that with a gas flow of substantially 4 cubic feet per minute per square foot through it, uncovered, a pressure differential of at least 1¼ inches of water is produced - and that in claim 1 the first of these descriptions was adopted and in claim 2 the second. The Deputy Commissioner then referred to earlier proceedings in which he had satisfied himself that the two definitions (so called) of what was meant by "relatively high resistance to gas flow" corresponded with one another and that therefore claims 1 and 2 referred to porous substances with substantially the same upper limit of permeability but in which he had decided that, because there was nothing in claim 3 to limit it similarly, "the specification was ambiguous in defining what was meant by the porous media of the invention in terms of "relatively high resistance to gas flow" "; so that without determining the opposition proceedings before him he had given the applicant an opportunity to amend. The Deputy Commissioner then considered the amendment sought pursuant to that leave and refused leave to amend because in his view the ambiguity of the phrase "relatively high resistance to gas flow" would, notwithstanding the amendment, remain.

Before me, as before the Deputy Commissioner, it was urged in opposition that even if the amendment fell within s. 71 and was not prohibited by s. 78 and was not otherwise open to objection on its merit, the application should nevertheless be refused because in an earlier decision between the parties a similar application had been refused and an appeal to this Court had been allowed to lapse. I agree with the Deputy Commissioner in thinking that the earlier decision - which related to a number of amendments - does not preclude the allowing of the amendment now sought and I need say no more about this aspect of the case.

It appeared to the Deputy Commissioner that there were two points of ambiguity. The first was that claims 1, 2 and 3 in the context of the specification as a whole indicated that there were three definitions of what was meant by "having low resistance to air-flow" and that although the definitions upon which claims 1 and 2 were based could be reconciled with one another as previously mentioned, he found himself "unable to co-relate the third definition with either of the other two". As a result he considered that the full range of media of relatively high resistance to gas flow was not ascertained. The second was that whereas in the body of the specification the invention was described in terms of the porous medium having a "pressure differential", claim 3 introduced as an essential element a comparison of the pressures required to pass a certain quantity of gas through the porous substance and through a two-inch layer of material respectively and it was not clear just how "pressure differential" and "pressure" were related to one another. To meet the second criticism the appellant, before me, relied upon an affidavit of an engineer, L. G. Golomb, wherein he deposed - "That if the pressure drop or pressure differential (which terms express the same concept of resistance to the passage of gas through a permeable substance) across a porous medium under specific conditions is greater than the pressure drop or pressure differential across a two-inch bed of pulverulent material in an unaerated state supported on such porous medium and under the same specific conditions it must also be the case that the pressure required to pass a specific volume of gas in a specific time through a specific area of such medium will be greater than the pressure required under the same conditions to pass the same volume of gas in the same time through the same area of such two-inch bed of material."

After full argument and an opportunity to consider this matter I do not think that if the amendment sought were to be allowed the claim as amended would create the ambiguities that the Deputy Commissioner envisages. It seems to me that, with the amendment, claim 3 would stand as a narrower version of claim 1 wherein as an additional requirement any porous medium to which it relates must have greater resistance to the passage of gas than has a two-inch bed of the material to be conveyed while unaerated and supported on the porous medium. Claim 3 so construed is, therefore, claim 1 with a further limitation and nothing can be within claim 3 unless it is also within claim 1. So reading claim 3 I do not think it makes it unclear what is meant when the specification requires media "having a relatively high resistance to air-flow" if this phrase is otherwise clear. Every porous medium having a permeability of less than 6 is within the range of the invention, but whereas claims 1 and 2 relate to apparatus with any such medium, claim 3 is confined to apparatus with a limited number of such media. It is to be observed, moreover, that from the body of the specification itself it appears that, although there is a top limit of permeability, namely 6, the permeability of the porous medium employed must be substantially below that top limit to enable many finely-divided substances to be conveyed. What claim 3 is directed to do is to define that degree of permeability in particular circumstances not merely by reference to the standard 6 but to that of the material to be conveyed as well. That it does so in terms of requiring a comparison of pressures rather than a comparison of pressure differentials does not as presently advised seem to me to render it ambiguous. It is hardly to be thought that the tests which the latter part of claim 3 contemplates are to be carried out except when, before the introduction of gas under pressure, the pressures above and below the porous medium and the two-inch layer of material are uniform (viz. atmospheric pressure).

I think, therefore, that the amendment sought does satisfactorily meet what I regard as the primary objection that the Deputy Commissioner took to claim 3. That it does not meet his secondary objection as well is not, in the view I take of claim 3, a sufficient reason for refusing to allow it.

During argument, however, it was contended on behalf of the respondent and the Commissioner of Patents that claim 3 was ambiguous in vital respects that were not brought to the notice of the Deputy Commissioner. I do not propose to refer to all of these but I will refer to those that I do regard as deserving thoughtful consideration. In the first place Mr. Hulme, for the Commissioner, contended that claim 3 was hopelessly ambiguous because it was really a method claim misleadingly cast in the form of an apparatus claim. His contention was that as the finely-divided material to be conveyed at the time might be any one of a large number of such materials, it would not be possible to determine whether there was any infringement of claim 3 except when the apparatus was working and material was being conveyed. I am not certain that this is strictly correct although I think it is clear that claim 3 is applicable only when there is a two-inch bed of a material upon the porous medium. The point of the contention was, however, that the permeability of any porous medium was in claim 3 defined not only by reference to its own permeability but to that of a large number of different substances and that this inevitably produced ambiguity, because a porous medium when covered by one material would be within the claim but when covered by another would be outside it. I am conscious of the difficulties that might be experienced in determining whether or not a porous medium was at any particular time within claim 3 but these seem to me to be practical difficulties more concerned with proof than with any ambiguity of language or conception. Somewhat allied to this argument was Mr. Franki's contention that what the latter part of claim 3 would require would be first, a measurement of the pressure required to pass a specified quantity of gas through the porous medium and then of the pressure required to pass the same quantity of gas at the same rate through the porous medium and a two-inch bed of the material to be conveyed and that it is contrary to all reason to think that the former could be greater than the latter, which is, according to his construction, what the claim would require. However, I do not so read the claim. It seems to me that it does require two tests - first of all, a test of the permeability of the porous material and in the second place, a test of the permeability of a two-inch bed of the material to be conveyed "while supported on said porous medium" and, although there may be all sorts of practical difficulties in making such a test, they, as it was admitted, are not matters that I can take into account on this application.

To deal with the arguments that have been addressed to me it is, I think, necessary to formulate what I consider to be the function of the Court in dealing with an application of this sort. In the first place, it must be satisfied that the amendment is by way of disclaimer, correction or explanation. Secondly, it must be satisfied that the specification as amended does not claim an invention substantially larger or substantially different from the invention claimed by the unamended specification and although the comparison that is involved in ascertaining this will usually require that both the original specification and the form it will take upon amendment are reasonably free from ambiguity, it is to be noticed that in Weiss v. Lufft [1] the cross-appeal which asserted non-compliance with s. 78 was dismissed notwithstanding that the appeal which contested a finding of ambiguity was also dismissed. There is, however, clearly enough a discretion to disallow an amendment which does fall within s. 71 and is not forbidden by s. 78. The conduct of the person seeking to amend is something to be taken into account, see Raleigh Cycle Co. Ltd. v. H. Miller & Co. Ltd. [2] , and it is not to be doubted that one ground for so refusing would be that the amendment is itself ambiguous or would introduce ambiguity into the specification. Weiss v. Lufft [1] was a case where the amendment sought was refused on this ground. Moreover, in particular cases where the Court is not only dealing with an application to amend but with the validity of the patent, it would be proper to refuse leave to amend because it would serve no useful purpose: Unifloc Reagents Ltd. v. Newstead Colliery Ltd. [3] . It seems to me, however, that it would only be in a rare case that an amendment should be refused which was in conformity with s. 71, was not forbidden by s. 78, was not itself ambiguous and did not import ambiguity into the specification on the ground that the specification, whether amended or not, was ambiguous. Acceptance of a specification may be refused on the ground of ambiguity and ambiguity may be raised as a defence in an infringement action or as the ground for revocation in revocation proceedings. In these circumstances it seems hardly necessary that upon an appeal under s. 76 the Court should embark upon a general review of the specification except to the extent that this is necessary for the purposes of ss. 71 and 78. Broadly speaking, the judicial discretion which s. 76 confers when ss. 71 and 78 are complied with does not usually require consideration of matters that are foreign to the amendment and its effect and do not relate to the conduct of the applicant. I find support for this limited view of the nature of the discretion in the decisions upon Kirk's Application [1] and James Gibbons Ltd.'s Application [2] . I would add that it seems to me that it would be inappropriate and might work injustice to decide upon an application of this sort substantial questions going to validity that are not involved with the amendment that it is sought to make. This is so particularly here when such questions were not raised before the Deputy Commissioner and the Deputy Commissioner has indicated that the fate of the objection proceedings before him may depend upon the result of this appeal.

(1941) 65 C.L.R. 528. 2. [1951] A.C. 278. 3. (1941) 65 C.L.R. 528. 4. (1943) 60 R.P.C. 165. 5. (1932) 49 R.P.C. 412. 6. [1957] R.P.C. 158, esp. at p. 162.

Before applying the principles I have stated to the case before me, it is necessary to deal with Mr. Franki's contention that, although in form a disclaimer, the making of the amendment would result in the specification claiming a different invention because an element of selection had been introduced. In making this contention he relied upon May & Baker Ltd. v. Boots Pure Drug Co. Ltd. [3] . I consider that case is distinguishable. There the reduction that the amendment would have effected was held to change the nature of the invention claimed; here it is not proposed to abandon claims 1 and 2 but merely to introduce a limitation in claim 3 that would exclude from its scope any material not already falling within claim 1. To do this is neither to enlarge nor to change the invention.

I find that the amendment sought is by way of disclaimer or correction, that it would not make the specification claim an invention substantially larger or different from that claimed previously, that it is plainly expressed and that it does not introduce ambiguity into the specification. In the circumstances of this case I do not think that any ambiguity that there may be in the specification as accepted warrants my refusing to allow an amendment that I consider is not only itself free from objection but is directed to meet something to which exception has been taken.

There is one other point to be mentioned. Mr. Hulme invited me, if I were to allow the amendment, to impose as a condition the requirement that claim 3 should be further amended to express in terms of pressure differential what is now expressed in terms of pressure because according to his reading this had been directed in earlier decisions which had not been challenged. Looking at these decisions I hardly think that they go as far as Mr. Hulme submits, although it is clear that the introduction in claim 3 of the concept of pressure in place of pressure differential was something that was criticised. Furthermore, had I the power, I would not be disposed to require the amendment of something that is not directly concerned with the amendment that I propose to allow and which I am not sure is either necessary or practicable. The appellant has chosen not to seek an additional amendment, notwithstanding the criticism that has been made of the claim, and I do not consider that I should either require him or give him the opportunity to take a course different from that which he has at his own risk chosen to follow. It is already twelve years since the application for this patent was made and I would be most reluctant to make any order that would further delay its being brought to finality.

The Commissioner did not ask for costs in the event of the appeal succeeding, so I allow the appeal and order the respondent to pay the appellant's costs.

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