ESCO Corporation v Ronneby Road Pty Ltd [2018] FCAFC 46

We previously reported the Federal Court decision in Ronneby Road Pty Ltd v ESCO Corporation [2016] FCA 588 (https://www.shelstonip.com/news/court-finds-claims-lack-utility-not-satisfying-composite-promise-patent-specification/) in which all claims of ESCO Corporation’s (“ESCO”) patent application AU 2011201135 for a Wear Assembly were found to lack utility on the basis that none of the claims were for an invention which achieved each and every one of six promised benefits listed in the specification.

By way of background, the claims of the patent application at issue relate to wear members having a certain lock mechanism for attaching to excavating equipment. The specification includes the following paragraph (“paragraph 6”):

The present invention pertains to an improved wear assembly for securing wear members to excavating equipment for enhanced stability, strength, durability, penetration, safety and ease of replacement.

The specification then proceeds to describe several different aspects of the invention, some directed to the wear assembly and some to components thereof (such as wear members), where each different aspect is described as providing certain benefits – some of which are listed in paragraph 6 and some of which are not.

Ronneby Road Pty Ltd asserted (and it was accepted by the primary Judge) that the list of advantages in paragraph 6 constituted a “composite” promise, and that accordingly, each of the six promises must be achieved by the invention in every claim in order for the invention to be useful. ESCO’s position was that the list of advantages in paragraph 6 was a statement of purpose and did not constitute a promise at all. Instead, ESCO submitted that the advantages described specifically in relation to the lock mechanism elsewhere in the specification constituted the true “promises” of the invention.

The Court’s job was thus to find the correct “promise” of the specification and then to ask whether the invention as claimed did what was promised by the patentee. In the end, their Honours agreed with ESCO and found that the true promises were to be found by looking at the body of the specification and the claims to find what the Court termed “degree[s] of symmetry” between the two. In this case, significance was placed upon the fact that there were two ‘clusters’ of claims, relating to the wear assembly and the wear member respectively, so that the relevant promise for each ‘cluster’ needed to be identified. The specific promise for claim 1 and its dependent claims was identified in other paragraphs of the specification, and that promise was achieved by the invention of the relevant claims.

Interestingly, as part of this decision, the Court reviewed Australian case law on utility and noted that if a specification, when properly construed, contains a composite promise, each and every advantage in that composite promise must be attained by the claims to meet the utility requirement. That is, under Australian law, a claim will lack utility if the invention fails to attain any one of the elements of a relevant composite promise.

This finding did not substantially influence the outcome of the present case since the composite promises, once correctly identified, were all satisfied by the claimed invention. It is, however, a reminder of the importance of carefully drafting patent specifications (or reviewing and amending during prosecution) to avoid composite promises, and where possible, exercising restraint when promising advantages in a patent specification, as any variation between what is promised and what is achieved could lead to a finding of inutility.