How an object statement can bring down your patent

Date: 2016-05-31

An Australian Court has just ruled that for a given patent claim to be valid, every promise about the invention in the specification must be delivered by enacting that claim.

In Ronneby Road Pty Ltd v Esco Corporation [2016] FCA 558 (‘Ronneby Road v Esco’), the Federal Court of Australia considered the validity of patent application 2011201135 (‘AU ′135’), concerning a wear assembly having a wear member, such as a tooth, that is removably securable to a 'base' on a digging edge of heavy excavating equipment. The Court considered issues of claim utility, novelty and fair basis, but this article discusses only the issue of utility.

Utility in Australia

For a claim to have utility in Australia, the claim must provide the result promised of the invention in the specification, and that result must be useful.1 

Under changes to Australian patent law introduced under the ‘Raising the Bar’ legislation,2 the requirements for utility were expanded to additionally require that a ‘specific, substantial and credible use’ be disclosed in the specification. This can be satisfied by an explicit disclosure or if a person skilled in the art ‘could appreciate the use, with their background knowledge in the art and without undue burden’.3  

The AU ′135 patent application considered in Ronneby Road v Esco was a pre-Raising the Bar patent application, so the additional requirement to disclose a ‘specific, substantial and credible use’ did not apply to this case.  

The invention

The specification disclosed 14 aspects to the invention, each of which related to features concerning either:

        (i) the design and geometry of stabilising surfaces along which the wear member is fitted to the base; or

        (ii) a moveable lock for securing the wear member to the base. 

The claims concerned only the features of the lock.

The promise

The invention was stated to provide the advantages of ‘enhanced stability, strength, durability, penetration, safety, and ease of replacement’. 

Although this statement appeared only once in the specification, the Court concluded that the specification promised all six of these advantages, in combination.

The outcome

The Court considered the utility of each claim independently. As commented above, the claims were only directed to the features of the lock, and while each of the claims fulfilled at least one of the advantages of enhanced stability, safety or ease of replacement, none of the claims resulted in enhanced strength, durability or penetration. 

The Court referred to case law that stated that by not meeting all of the promises in the specification there was a partial failure of the consideration required for a patent, and the Court concluded, therefore, that each claim was invalid. 


Though this case concerned a pre-Raising the Bar patent application, existing case law on utility is not intended to be displaced by the Raising the Bar legislation,4  so this case appears equally relevant to new patent applications.

The case stresses the importance of not promising too much in the specification about advantages of the invention. There is a particularly high exposure to an attack on validity if the specification presents ‘the invention’ as providing multiple advantages, especially if the different advantages are respectively provided by different embodiments of the invention.


1 Artcraft Urban Group Pty Ltd v Streetworx Pty Ltd [2016] FCAFC 29 at [120]-[121]; Streetworx Pty Ltd v Artcraft Urban Group Pty Ltd [2014] FCA 1366 at [340]

2 Intellectual Property Laws Amendment (Raising the Bar) Act 2012.

3 Explanatory Memorandum, Intellectual Property Laws Amendment (Raising the Bar) Bill 2011 [2012], 45.

4 Ibid.