Mining equipment patent lives up to (some of) its promises
Patents – novelty – whether language in claim described the function of integers for a locking mechanism or also specified position – utility – “promise” of the invention – “composite” promises – specification refers to multiple advantages conveyed by the invention – whether promises to be interpreted cumulatively or disjunctively
ESCO Corporation v Ronneby Road Pty Ltd  FCAFC 46
Rock is famously hard. Equipment used to dig up rock needs to be even harder. Unfortunately, the process of digging leads to parts of the equipment (like excavating buckets and “cutterheads”) wearing out over time through abrasion, friction and environmental conditions. Rather than replace such parts, “wear members” are affixed to the digging edges of such machinery and, as the name suggests, these wear out instead and can be replaced.
The appellant (“ESCO”) was the applicant for a patent for a “wear assembly” to secure wear members to excavating equipment. The invention relates to a device for securing wear members to excavating equipment. In essence, the invention is a movable lock that can be placed in either a “hold position” (to keep a wear member attached to a base – the digging edge of the equipment) or a “release position” for when the wear member needs to be removed. In the specification of ESCO’s patent application (“Application”), the author explains that design efforts for wear assemblies are directed towards enhancing their “strength, stability, durability, penetration, safety and/or ease of replacement” (the “six design features”). According to paragraph 6 of the specification, the invention described in the Application “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 respondent (“Ronneby”) was one of three unsuccessful opponents to the Application. Ronneby appealed that decision to the Federal Court, and was successful on its grounds of opposition based on want of novelty and utility. The learned trial judge found that the majority of the claims in the Application lacked novelty, and none that of them was a claim for a useful invention. ESCO appealed that decision to the Full Court (Greenwood, Rares and Moshinsky JJ), and was successful.
On the question of novelty, the primary judge found that claim 1 in the Application, and eight other claims said to be “directly or indirectly” dependent on claim 1, had been anticipated by an existing product called the Torq Lok. The Torq Lok is a locking pin (screw) that is inserted into a polymer retainer fitted into a cavity in the wear member. The primary judge considered that the “hold position” and “release position” referred to in claim 1 were functional descriptions rather than references to pre-determined or fixed positions. While accepting that claim 1 describes a lock that operates in a “broadly binary way”, the primary judge concluded that the Torq Lok also has “hold” and “release” positions within the meaning contemplated by claim 1, and thereby anticipated the claim.
ESCO contended that this construction erroneously concentrated only on part of the language of claim 1, to the exclusion of other parts of the claim and specification that indicated that the “hold” and “release” positions were determined by reference to the lock and its relationship with the point of attachment (the “through-hole”). In contrast, a screw (like that in the Torq Lok) does not have pre-determined positions; it is simply screwed in or retracted along a continuum, the thread. The Full Court agreed, noting that the claim identifies a lock that can be moved between two (binary) positions; the functions to which the primary judge referred were enabled by this feature. The primary judge erred in failing to take into account that language of the claim (and similar indications in the specification).
On the question of utility, at first instance Ronneby argued that the advantages of the invention “promised” by the authors of the Application were enhancements to the six design features, and that these advantages were expressed “cumulatively” such that all six design features had to be delivered by every claim in the Application. ESCO contended that the “promises” of the invention were to be found by having regard to the specification as a whole, and the relevant advantages were dealt with respectively in separate claims; enhancements to all six design features did not need to appear in every claim. In other words, ESCO argued that it is sufficient that a claim produce one of the results described in the specification. The primary judge accepted that the promise in the Application was at least “textually composite”. After considering various authorities dealing with patents in which some, but not all, promised advantages of an invention fails to be achieved by the relevant claims, the primary judge concluded that the weight of authority favoured Ronneby’s position.
On appeal, the Full Court discussed at length the history of the requirement for patentability in section 18(1) of the Patents Act 1990 (Cth), that “the invention, so far as claimed in any claim…is useful”, and authorities that have considered the fate of claims that only partially fulfil the “promise” of the invention or produces other, non-useful, results. The Full Court accepted (at ) that the starting point “is to recognise…that utility ‘depends upon’ whether, by following the teaching of the [Application], the result claimed is produced”. That process requires the court to “follow the teaching of the complete specification to isolate the promise of the invention and determine whether the result claimed is produced”: . The Full Court also accepted (at ) that where a specification “contains a ‘composite’ promise for the described invention, a failure to attain any one of the elements of the composite promise in any claim defining the invention renders the invention so far as claimed in any claim, inutile”.
The Full Court noted that the present case was not one in which the applicant seeks a monopoly over both useful and non-useful results, or has included claims that would not produce a desired result if followed. Accordingly, the starting point was to consider whether a “composite” promise had been made, and to consider the claims and the body of the specification to identify what aspects of the described invention were made the subject of the claims. On that basis, the Full Court agreed with ESCO that the reference to the six design features in paragraph 6 of the specification was not a “promise” per se, but rather identifies topics to which the invention related. Even if paragraph 6 contained a promise, consideration of the language in the specification and claims (notwithstanding the use of the conjunction, “and”) indicated that the reference was to be read disjunctively, as a collection of promises.
The teaching of the specification contemplated two “clusters of claims” that defined the invention. In such a case, it was necessary to consider the claims in the context of the specification to “identify what degree of symmetry exists between the subject matter of the claims […] and the paragraphs of the Specification which contain the promise relevant to those claims”: . The court should not favour a construction of the complete specification that brings about “discontinuity” or “asymmetry”. On that basis, claim 1 of the Application could be seen to be directed to some of the aspects of enhancement referred to in the relevant paragraphs of the specification, and this was sufficient to fulfil the requirement of utility. The remaining claims similarly were useful, being directed to at least one of the six design features. Accordingly, the Full Court allowed the appeal.
As an aside, between the hearing of the Full Court appeal and its handing down of reasons, the Canadian Supreme Court handed down its decision in AstraZeneca Canada Inc v Apotex Inc  1 SCR 943, concluding that the utility requirement in Canada’s patents statute is to be interpreted in line with the purpose of preventing the patenting of fanciful, speculative or inoperable inventions. In contrast to the Full Court in the present case, the Supreme Court held that the utility requirement does not involve determining whether promises made in the specification are met – “promises are not the yardstick against which utility is to be measured”. The Supreme Court held that the “promise doctrine” “undermine[d] a key part of the scheme of the Act; it is not good law”, citing British United Shoe Machinery Co v A Fussell & Sons Ltd (1908) 25 RPC 631.