Case: Minnesota Mining and Manufacturing Company v Beiersdorf (Australia) Limited [1980] HCA 9 ; (1980) 144 CLR 253
Outcome: cited
determining the boundaries of a claim, the specification must be read as a whole. It describes the patentee's best known method. If the language of a claim is clear and unambiguous, it is not to be rendered ambiguous, obfuscated or qualified by statements extracted from the specification as if those statements form part of the language of the claim defining the monopoly ( Flexible Steel Lacing Company v Beltreco Ltd [2000] FCA 890 ; (2000) 49 IPR 331). Although the language of the claim defines the monopoly, the claim marks out the boundary of a particular solution to a problem not solved by the prior art and thus has a context. Reference should be made to the specification to understand that context, to explain the background to the claims and to ascertain the meaning of technical terms ( Minnesota Mining and Manufacturing Co. v Beiersdorf (Aust) Ltd [1980] HCA 9 ; (1980) 144 CLR 253). Although the clear language of a claim should not be diluted, qualified or obfuscated by reference to the specification, unclear language used in a claim might usefully be made clear by reference to words used in the specification, in the relevant context ( Kimberly-Clark Australia Pty Ltd v Arico Trading International Pty Limited [2001] HCA 8 ; (2001) 207 CLR 1). The specification will, among other things, describe aspects of the prior art, unresolved problems in the prior art, the object the invention seeks to achieve and preferred embodiments of the invention and will recite a claim or claims staking out the patentee's exclusive ground. The Court reads that document in the logical sequence of its contentions and seeks to construe the claims, according to the words chosen in the claims, taking account of those matters, recognising that an identified embodiment or a preferred embodiment does not limit the natural language of a claim yet, the patentee may by clear language choose to limit the scope of the monopoly. A question arises as to the significance of claim 14 of the patent as an aid to the construction of claims 1 to 13. Claim 14 claims the spring clutch of claim 13 where the spring "is of unitary construction". Claim 14 was introduced into the patent by amendment by leave granted by IP Australia on 1 November 2006 consequent upon an application made by the patentee on 24 October 2006. Amendments to claim 13 were made at the same time (see [17] and [18] of these reasons). Mr Hunter gave evidence that claim 14 does not add anything to the scope of claims 1 to 13 as those claims comprehend a helical spring of unitary construction with reverse winding and a plurality of helical springs of alternate winding which operate in the same way as a spring clutch incorporating a spring of unitary construction with reverse winding. In that sense, it is not said by Mr Hunter or SBriggs that claim 14 aids in the construction of claims 1 to 13 on the footing that claim 14 prescribes a monopoly directed to the integers of claim 13 limited to a unitary spring and thus claim 13 must address something other than a spring clutch incorporating a unitary spring. It is not said that, by inference drawn from claim 14, claims 1 to 13 are directed to multiple adjacent separate springs of alternate winding. SBriggs says claims 1 to 13 bring within the monopoly a helically reverse wound unitary spring and a plurality of springs that cause the spring clutch of Exhibit 1 to operate in the same way as a spring clutch incorporating a reverse wound unitary spring. As Mr Hunter points out, it is then difficult to see exactly what claim 14 adds to the scope of claims 1 to 13, on that view of those claims. Mr Hunter is correct in this respect. The language of claim 13 requires as an essential integer of the monopoly, the presence of a single reverse wound unitary spring. The introduction into the patent of claim 14 (in its current amended terms) with the result that selective engagement of the tabs of the helical spring of claims 1 to 12 , was elevated into an amended claim 13 as part of a redefined control means (see claim 13(3)(a) and (b)), does not say anything about the helical spring of claims 1 to 12. In order to construe the language of claims 1 to 13 post-amendment in a way which extends the integers of those claims to multiple separate springs of alternate winding, further amendments would have been necessary to claims 1 to 13 to adopt clear language that brought a plurality of springs within the boundaries of the monopoly. That result does not arise simply by inference from an amendment to claim 14 (and related amendments to claim 13). The express reciting in claim 14 of a spring of unitary construction adds nothing to claims which address a single unitary spring of reverse winding. Having regard to the construction adopted in relation to claims 1 to 13, it follows that the threats of infringement proceedings made by SBriggs by the letter from its solicitors to Uniline dated 4 April 2007 and the further letter dated 16 July 2007 from those solicitors to the patent attorneys for Uniline are unjustifiable as no infringement is made out. The Amended Cross-Claim for infringement of the patent in suit fails. Issues going to validity of the patent assuming the "counter-factual" (construction) hypothesis General approach Claim 13 of the patent in suit demands the presence of a single unitary reverse wound spring engaging a longitudinal slot and key device. Plainly, that invention is not anticipated by US Patent 643. If claim 13 extends to the inclusion of a plurality of multiple springs of alternate winding with tabs engaged by the control device of claim 13, is that invention disclosed by US Patent 643? Each expert has sought to answer that question by applying a different method of analysis. Mr Hunter isolated the essential features of claim 13 (and other claims upon which it depends) and compared those features with the invention disclosed by US Patent 643, that is, the novel elements claimed for the invention (Table A, para 38, Hunter affidavit, 6 March 2008). Mr Hunter could not see all the integers of claim 13 in the integers of the invention of US Patent 643 (claims 3, 4, 5, 6, 7, 9, 12, 13 (as to a helical spring for the purposes of claims 3 7, 9 and 12; and as to the feature of a single longitudinal opening defined by edges selectively engaging one or more of the tabs of the spring) and 14). Thus, no anticipation arises in his view. Mr Hunter separately considered the essential features with the prior art disclosures identified in US Patent 643 (Table B, para 38, Hunter affidavit, 6 March 2008). Mr Hunter could not see all of the integers of claim 13 in the prior art (claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, claim 13 (because the prior art does not disclose alternate wound springs, but otherwise all essential elements of claim 13 disclosed) and 14). Mr Hunter did not accept as correct, the methodological approach adopted by Dr Gilmore to determining anticipation by looking to the prior art disclosures of US Patent 643 and the disclosures in that part of US Patent 643 which identify features of novelty in the invention (and ultimately the integers of the claims of that patent) so as to put the disclosures together to see and understand whether the combination of claim 13 of the patent in suit is disclosed in US Patent 643. SBriggs says that, unremarkably, US Patent 643 discusses the prior art and then distinguishes the invention from it. It does so, in part, by depicting embodiments of the invention in drawings 7 to 13 and distinguishing the invention from the prior art depicted in drawings 1 to 6. The specification describes the shortcomings of prior art clutches manifested in variations in frictional drag due to differential radial loads at bearing surfaces of prior art clutches (see [127] and [128] of these reasons). SBriggs says that the specification teaches away from the prior art and combinations evident in the prior art. It says Mr Hunter, as a skilled addressee, is led away from the prior art configuration of a single longitudinal slot to the particular features of US Patent 643 in which novelty is claimed as determined by the integers of those claims. Mr Hunter cannot see the combination of a plurality of springs of alternate winding engaging a non-complex single longitudinal slot and key device, in any of those claims. Mr Hunter separately compares the prior art of Figures 1 to 6 with the discussion of the prior art and concludes that the integers of claim 13 are not disclosed in the prior art. In particular, the prior art does not disclose springs of alternate winding. Moreover, US Patent 643, it is said, does not claim a clutch that includes a second shaft with a single longitudinal opening with edges of that opening that selectively engage one or more of the tabs, as claim 13 of the patent in suit requires. The method adopted by Mr Hunter might usefully lead the skilled addressee to an answer to the question of whether the integers of claim 13 are anticipated by US Patent 643. Mr Hunter has sought to find that answer by looking to the prior art disclosures. He has looked to the discussion of the invention, the assertions of novelty and the integers of the claims of US Patent 643 to see if he can find the integers of claim 13 revealed in those claims. If the answer to either inquiry conducted by Mr Hunter is yes, the method would usefully reveal anticipation. If the answer to either inquiry is no, the method may simply reflect an impermissibly restricted inquiry. In determining whether a document, in this case US Patent 643, discloses the integers of claim 13, it is legitimate to look to the whole of the document to isolate the presence or disclosure of elements of the combination of claim 13 in the prior art (and relevant drawings) and in the discussion of the advantages of the invention over the prior art, the integers of the claims recited in the patent and drawings embodying the invention. The disclosures in the patent taken as a whole may reveal to a skilled addressee, the combination of the claim in the patent in suit. If, however, the combination is to be found in a combination of disclosures rather than a disclosed combination , the skilled addressee must see and reach the combination without calling in aid his own inventive skills or ingenuity in making the combination. Nor will the disclosures anticipate the combination of claim 13 (assuming the counter-factual) even though putting together the combination might be obvious to a person skilled in the relevant art (whether Dr Gilmore or Mr Hunter or any other skilled addressee). US Patent 643 does not disclose the combination of a plurality of springs of alternate winding engaging a non-complex single longitudinal slot and key configuration to facilitate smooth transition of rotational forces between the input and output shafts of a spring clutch. The patent addresses use of multiple springs (some of which may be reverse wound in one embodiment) to support the output load in a way that overcomes an asymmetrical application of supporting forces (that produces reaction forces at the bearing surface within the clutch) by configuring a clutch employing a multiplicity of springs so as to support the load with very nearly a pure couple of forces without producing reaction forces in the bearings as a direct result of the forces produced by the springs. The invention thus eliminates frictional drag and US Patent 643 is entirely directed to that objective. The discussion in US Patent 643 of firstly the disadvantages of prior art clutches and secondly, the manner of overcoming frictional drag by a pure couple of forces, does not disclose the combination of claim 13 of the patent in suit. To the extent that such a combination might be revealed to a person skilled in the art, such a person would need to apply an inventive step in doing so. Thus, applying the counter-factual, US Patent 643 does not anticipate the combination of claim 13 of the patent in suit. False suggestion