THE DINCEL ARGUMENTS
52 The five sub-grounds of appeal may be considered together.
53 As noted, Dincel's main claim in relation to the construction of the Patent is that the primary judge erred in construing claim 1 by importing into it an additional requirement of the need for mechanical advantage. The principles of construction are well established in Jupiters Ltd v Neurizon Pty Ltd (2005) 222 ALR 155 where the Full Court (Hill, Finn and Gyles JJ) (at [67]) said:
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(i) the proper construction of a specification is a matter of law: Décor Corporation Pty Ltd v Dart Industries Inc (1988) 13 IPR 385 at 400;
(ii) a patent specification should be given a purposive, not a purely literal, construction: Flexible Steel Lacing Company v Beltreco Ltd (2000) 49 IPR 331; [2000] FCA 890 at [81]; and it is not to be read in the abstract but is to be construed in the light of the common general knowledge and the art before the priority date: Kimberley-Clark Australia Pty Ltd v Arico Trading International Pty Ltd (2001) 207 CLR 1; 177 ALR 460; 50 IPR 513; [2001] HCA 8 at [24];
(iii) the words used in a specification are to be given the meaning which the normal person skilled in the art would attach to them, having regard to his or her own general knowledge and to what is disclosed in the body of the specification: Décor Corporation Pty Ltd at 391;
(iv) while the claims are to be construed in the context of the specification as a whole, it is not legitimate to narrow or expand the boundaries of monopoly as fixed by the words of a claim by adding to those words glosses drawn from other parts of the specification, although terms in the claim which are unclear may be defined by reference to the body of the specification: Kimberley-Clark v Arico at [15]; Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at 610; Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461 at 478; the body of a specification cannot be used to change a clear claim for one subject matter into a claim for another and different subject matter: Electric & Musical Industries Ltd v Lissen Ltd [1938] 4 All ER 221 at 224-5; (1938) 56 RPC 23 at 39;
(v) experts can give evidence on the meaning which those skilled in the art would give to technical or scientific terms and phrases and on unusual or special meanings to be given by skilled addressees to words which might otherwise bear their ordinary meaning: Sartas No 1 Pty Ltd v Koukourou & Partners Pty Ltd (1994) 30 IPR 479 at 485-6; the Court is to place itself in the position of some person acquainted with the surrounding circumstances as to the state of the art and manufacture at the time (Kimberley-Clark v Arico at [24]); and
(vi) it is for the Court, not for any witness however expert, to construe the specification; Sartas No 1 Pty Ltd, at 485-6.
54 The wording of the claims must be construed in context and in light of the common general knowledge before the priority date, but their meaning cannot be altered by any gloss drawn from other parts of the specification. While expert evidence may assist, the proper construction of the claims is a matter of law for the Court.
55 In relation to the "ramp surfaces integer", Dincel says that it is apparent that claim 1 is directed to a building element that can be connected to another like element by a snap engagement mechanism. In general terms, each element has flanges on one end and grooves on the other. As the elements are pushed together, the flanges and grooves move relative to one another and transverse of the element. The elements have "ramp surfaces that engage the flanges to move flanges for said snap engagement of the flanges in the grooves". This is the "ramp surfaces integer". The movement that is referred to, is movement of the flanges and grooves relative to each other. Dincel contends, as it did at first instance, that the function of the "ramp surfaces" is as spelt out expressly in the ramp surface integer, namely, to engage the flanges to move the flanges relative to the grooves for the snap engagement of the flanges in the groove to occur. Dincel contends there was no requirement that the ramp surfaces convey any particular "mechanical advantage" over and above that function, contrary to what the primary judge held.
56 Dincel argues that "ramp surfaces" means simply a slope or inclined surface extending from an adjacent surface. The remaining words in the ramp surface integer define the function that must be performed by the ramp surfaces, that is the functional requirement is to engage the flanges to move the flanges for "said snap engagement" with the grooves. Dincel challenges the finding of the primary judge that a ramp surface within the meaning of claim 1 must confer a "mechanical advantage" by "reducing the amount of the force required to achieve [movement of the flange]". At [38] of the liability judgment, his Honour said:
Mr Phillips understood that the ramp surfaces referred to in the Patent are sloping surfaces that provide a mechanical advantage by reducing the amount of force required to move the flange from point to point. Mr Hunter, in his third affidavit, agreed with Mr Phillips, that a surface must function as a ramp to be a "ramp surface" for the purpose of the claims. Mr Phillip's understanding accords with my own understanding of how the invention described in the body of the specification works.
(Emphasis added.)
57 Dincel contends there is no justification for introducing this requirement. It was a concept introduced by Mr Phillips, and responded to by Mr Hunter, but Dincel contends that the experts' application of the concept of "mechanical advantage" was different from the primary judge's application. Dincel contends that the experts used the term "mechanical advantage" to describe the conceptual, technical framework that underlies the functional requirement. In contrast, the primary judge applied "mechanical advantage" as an additional requirement that a surface had to meet in order to be a "ramp surface" within the meaning of claim 1 over and above the definitional and functional requirements on which Dincel relied. The function of the ramp surface it says is simply to engage the flanges to move the flanges for snap engagement of the flanges in the grooves. This is the express functional requirement, but the primary judge imported a different and additional functional requirement, namely, that the ramp surfaces provide a "mechanical advantage". Dincel says this is unwarranted because claim 1 already prescribes in terms the function of the ramp surfaces. To the extent that it goes beyond the express functional requirement, Dincel says it is inconsistent with the wording of the claim. Dincel contends this adds, in effect, an impermissible gloss to the words of claim 1.
58 Dincel stresses, as the primary judge acknowledged, that neither the body of the specification, nor the claims refer to "mechanical advantage". Dincel challenges the primary judge's finding (at [39]) that "these words do describe the work performed by the 'ramp surfaces', of the combination defined in claim 1 as it would be understood by the skilled addressee based on a reading of the specification as a whole". At [56] of the liability judgment, the primary judge said:
Mr Hunter's evidence clearly establishes that the movement of the groove is assisted by what he also calls a ramp surface in the AFS Product (shown in green in Schedule A, Figs 1-5) on the outer surface of the flange. It is this inclined surface that assists the groove to move in a downward direction relative to the flange to a point at which snap engagement can occur. It is clear that it is this surface in the AFS Product that provides most, if not all, of the mechanical assistance necessary to enable snap engagement to occur.
59 This is an example, Dincel says, of the way in which the primary judge applied the "mechanical advantage" requirement. His Honour compared the ramp surfaces on the grooves with the ramp surfaces on the flanges in the AFS Product and found that it was the ramp surfaces on the flanges that were providing "most, if not all, of the mechanical assistance necessary to enable snap engagement to occur". This process led his Honour to conclude that the surfaces on the grooves in the AFS Product were not "ramp surfaces" within the meaning of claim 1 (at [58]).
60 Once it is accepted that mechanical advantage is not required, Dincel says it must follow that the AFS Product embodies the ramp surface integer, it being clear that the "upper ramp surfaces" in the AFS Product are ramp surfaces that perform the function of engaging the flange to move the flanges relative to the grooves for the snap engagement of the flange in the grooves.
61 Dincel asserts that properly construed as a whole, and with no additional functional requirement in the words "ramp surfaces", the ramp surface integer requires "sloping or inclined surfaces that engage the flanges to move the flanges for snap engagement in the grooves", nothing more and nothing less. It says the integer must be present in the AFS Product because the "upper ramp surfaces" in the AFS Product are plainly sloping or inclined surfaces. Consistently with this, the evidence shows, Dincel argues, that the flanges must ride over the upper ramp surfaces to get into the grooves so that they traverse the whole of the upper ramp surfaces. Dincel argues that, contrary to the AFS's submission, the evidence shows that the flanges move while they are traversing the upper ramp surfaces. That movement can only be attributable to the engagement with the upper ramp surfaces, as explained by Mr Hunter before the primary judge. There is nothing else contacting the flanges at that point that could cause such movement. Finally, the movement of the flanges is for snap engagement with the grooves because, after traversing the upper ramp surfaces, the flanges snap into the grooves. Dincel argues that this means that all the disputed elements of claim 1 are present in the AFS Product.
62 Dincel points to evidence that the relative movement of the flanges and the grooves of the AFS Product during snap engagement involved about 37.5% movement of the flanges and 62.5% movement of the grooves, which was a figure broadly consistent with Mr Hunter's measurements and calculations indicating that about 25% of the movement was attributable to the flanges. It follows that there was clear evidence, according to Dincel, that a substantial proportion of the overall relative movement of the flanges in the grooves during the snap engagement with the AFS Product involved the movement of the flanges. This was important because it is also clear that movement of the flanges was caused by the "upper ramp surfaces" engaging the flanges. Dincel contends that in the proper construction of claim 1, without any reference to, or requirement of, "mechanical advantage", that is sufficient to establish the presence of the ramp surface integer and, thus, infringement of claim 1 by the AFS Product.
63 Alternatively, and in any event, Dincel submits, even on the primary judge's construction of the claim, there was evidence of mechanical advantage of the kind contemplated, such that the ramp surface integer was present in the AFS Product. There was evidence of the overcoming of the snap interference or engagement distance as discussed above at [13]. The snap interference distance is the distance the two elements of the product must move relative to one another in order for the product to "snap-fit" or snap shut. No finding was made about the amount of the "snap interference distance" in the AFS product, that is, the total amount of relative movement between the groove and the flange necessary to effect the "snap-fit". Dincel argues that the primary judge should have found that this distance was about 2 millimetres of a total snap interference distance of about 5-6 millimetres.
64 Dincel further contends that there was evidence before the primary judge, if required, that the ratio of the relative movement of the flanges and the grooves in the AFS Product remained the same throughout the process of snap engagement. No finding was made to the contrary. It follows, Dincel argues, that the proportion of relative movement attributable to movement of the flanges during the final 2 millimetres of the snap engagement is the same as the proportion attributable to movement of the flanges throughout the snap engagement, that is, being 37.5% or, in the alternative, 25%, as found by Mr Hunter.
65 This means, Dincel argues, that there was evidence of the particular contribution to the movement of the flanges made by the upper ramp surface. That contribution was not, Dincel argues, de minimus. As for the quantum of that effect, Mr Hunter's evidence, based on his figure of 25%, was that the flanges would move about 0.5 millimetres as they traversed the upper ramp surfaces. That would be higher, if the figure of 37.5% were applied. Dincel argues 0.5 millimetres could not be regarded as de minimus in the context of the invention described and claimed in the Patent. Snap engagement requires small, not large, distances. There was evidence that an entire snap engagement can be effective with a "snap interference distance" of 0.5 millimetres.
66 Dincel argues that for the same reason the primary judge erred in finding that the outer surfaces of the flanges in the AFS Product provided most, if not all, of the mechanical assistance necessary to enable snap engagement to occur and erred in finding that the evidence did not establish that the upper ramp surfaces made any contribution, or any significant contribution, to the movement of the flanges. There was no contest at trial as to whether the upper ramp surfaces were sloping surfaces extending from adjacent surfaces. As for the functional requirement, Dincel argues that, if necessary, the upper ramp surfaces did provide a mechanical advantage during the process of snap engagement. They made it easier for the flange to traverse over that portion of the groove and make its way into the slot by making the deformation of the flange more gradual than it would otherwise be. Dincel contends that it therefore follows, for the same reason, that the primary judge erred in finding that the upper ramp surfaces in the AFS Product were not ramp surfaces within the meaning of claim 1.