In Australia, a patent opposition is an opportunity for a third party to oppose the grant of a prospective patent at the patent office. A patent opposition is akin to Inter Partes Review or Post Grant Review in the US or opposition in Europe. Recent success by Freehills Patent Attorneys flies in the face of the prevailing view of the Australian IP community that it is hard for opponents to win an Australian patent opposition on the ground of obviousness.

This article discusses the successful grounds upon which the opponent succeeded in Vermeer Manufacturing Company v Wirtgen GmbH [2015] APO 14. The opponent succeeded on the grounds of novelty and obviousness over a prior patent specification (D1) and on the ground of obviousness over the common general knowledge.

The success is attributed to several factors including a clearly delineated evidence plan, careful expert selection and meticulous evidence preparation by Freehills Patent Attorneys.


Wirtgen filed Australian patent application no. 2009212871 covering road profilers and surface miners. Surface miners, typically used in surface mining of iron ore and coal, employ a rotating drum that has an array of teeth or picks provided on it that engage with and dig up the surface.  The picks need to be monitored for wear and damage, and need regular replacement. Road profilers have the same configuration, although typically smaller, and are used to dig up asphalt prior to resurfacing.

The invention involved a method of measuring the length of the pick and comparing that measurement to a reference value stored in memory to provide a quantitative indication of the wear.

Vermeer opposed the grant of the patent application.

The prevailing difficulties

Obviousness is hard to establish in Australia. Until a recent law change1, it was even harder to establish obviousness in patent office matters and the present case falls within that “harder” category. As stated by the hearing officer, the opponent “must establish that it is clear or practically certain that the patent is invalid”2.

Inherent lack of novelty in light of D1

The D1 reference did not explicitly match all the features of the invention. Evidence from technical experts in the field played an important role to enable the hearing officer to hold that even though one or more features were not explicit in the D1 reference, those features were implicitly disclosed3.

Obvious over D1

The opponent also succeeded on this ground.

In Australia, the assessment of inventive step is from the viewpoint of the person skilled in the field. Thus, testimony from technical experts is used to indicate the knowledge base and mode of thinking for such a skilled person, even though that skilled person is really only a hypothetical construct.

The opponent’s experts were engineers with experience in heavy mobile equipment, surface miners or road profilers. On the other hand, the applicant attempted to argue that the skilled person was an operations or maintenance manager for the equipment with a narrower knowledge base and perspective. It is a common tactic for applicants to “dumb down” the person skilled in the field, because their knowledge base is smaller and such a person is less likely to consider something obvious.

The hearing officer settled on the opponent’s view of the skilled person which was the more highly skilled of the two options. The opponent’s selection of suitable experts, supported by case law, was therefore a factor in the opponent’s success.

Evidence approach

The hearing officer also considered the inventiveness of dependent claims relating to the use of a rotational position sensor to find the location of picks on the rotating drum in need of replacement.

This exemplifies that a careful and thoughtful approach to evidence preparation pays off. Evidence obtained by showing the technical expert the patent specification and asking whether a feature is obvious is usually tainted because it is well accepted that things seem more obvious in hindsight. To avoid this taint, a “black box” approach is taken where the expert is not shown the patent specification and instructed not to look at it. If non-leading questions can be posed and the expert comes up with the same idea without difficulty then there is a strong platform for arguing that the invention is obvious. The opponent’s expert came up with the solution of a rotational position sensor and no other solutions were provided by the applicant’s experts, these being deciding factors in finding that the claim was obvious4.

Obvious over Common General Knowledge

The opponent also compiled a solid foundation of evidence from the technical experts as to the state of common general knowledge in the field. The evidence established that it was well recognised in the art that visual inspection for tool wear and breakage would require downtime of machinery. The evidence also proved that it was known in the field to visually inspect picks and make a mental measurement and comparison with a reference value stored in the operator’s brain or an operating manual.

Given the state of the common general knowledge, the hearing officer thought it was clear that the invention “seeks to…automate what was previously done manually by an operator of the machine”5 and concluded that the invention lacked inventive step over common general knowledge in the field. Again, black-box evidence from the opponent’s technical experts that they would solve the problem using some sort of sensor to measure the length and compare it with a reference value aided the hearing officer in coming to his decision. The hearing officer seemed particularly taken with one expert’s view that the very idea of using sensor technology and comparing it to a reference value was ‘beyond obvious’6.

Take home lessons

The decision shows that the quality of evidence will affect success in a patent opposition. At Freehills Patent Attorneys, we recommend the following approach to evidence preparation:

1. Start evidence preparation early The typical approach to patent oppositions is to take a step-wise approach which leaves only a short time (3 months) for evidence preparation. We recommend commencing at the earliest possible opportunity to allow up to 9 months for evidence preparation, enabling us to prepare a far superior case than what could be achieved in 3 months.

2. Have a clearly delineated plan A clearly delineated plan is essential from the outset. For one, it will allow identification and resolution of conflicts in evidence preparation. For example, obtaining “black box” evidence from an expert may conflict with the need to obtain the expert’s view on the meaning of terms in the opposed specification. Is the plan achievable within the time available?

3. The ‘KISS’ principle “Keep It Sweet and Simple”. The hearing typically takes less than a day. Therefore, overly complex arguments with subtle nuances are unlikely to succeed in that environment. The plan should be developed with that in mind.

4. Choose experts wisely The choice of one or more independent experts will follow from the clearly delineated plan of the case to be proved. We pay attention to expert selection according to the established case law.  More than one expert may be required to corroborate the point to be proved or to resolve conflicts in the evidence plan.