Here’s the drill: The Full Federal Court clarifies the requirement that patents disclose the ‘best method’ of performing the invention
The Full Federal Court recently drilled down on the ‘best method’ requirement in Australia in Sandvik Intellectual Property AB v Quarry Mining & Construction Equipment Pty Ltd  FCAFC 138.
Under Section 40(2)(aa) of the Patents Act 1990 (Cth) a ‘complete specification must … disclose the best method known to the applicant of performing the invention’. This requirement has been increasingly pleaded as a ground of revocation in patent disputes in recent years – making cases like Sandvik and the earlier Full Court decision of Laboratoires Servier v Apotex Pty Ltd (2016) 247 FCR 61 the proverbial canaries in the coal mine.
The patent in suit was for an ‘extension drilling system’ for use on semi-automatic drilling rigs in underground mining structures (specifically, coal mines) to drill holes into which ‘rock bolts’ could be inserted to secure the ceiling structure of the mine. Specifically, the invention related to the configuration of drill rods used to drill into the ceiling of the mine that was said to overcome issues associated with uncoupling the drill rods after the completion of the drilling.
Sandvik alleged that Quarry Mining infringed the patent. At first instance, the Court upheld Quarry Mining’s claim that the patent was invalid, including on the ground that the patent did not describe the best method known to Sandvik of performing the invention.
The primary judge’s decision largely turned on evidence provided by one of the inventors that, by the time of filing the complete specification, Sandvik had developed a sealing member for use in the extension drilling system that was better than that described in the specification. The sealing member that was not disclosed was said to prevent leakage of flushing fluid (water) that was continuously pumped through the drill rods to clear away cuttings and prevent jamming. The inventor described the sealing member as ‘the ultimate evolution of the seal’ and a ‘superior design’ to that disclosed in the specification and the design of an effective water sealing mechanism as a ‘real issue which needed to be overcome’ when developing the drilling system. A detailed technical drawing of the superior sealing member had been prepared prior to filing, but was not included in the complete specification. The specification made no other mention of the sealing arrangement. Placing particular emphasis on evidence that the sealing member was not ‘some minor or incidental dimension of what was perceived by the inventors as the best method of performing the invention’, the primary judge concluded that Sandvik had not disclosed the best method known to it of performing the invention.
On appeal, Sandvik argued that the detailed characteristics of the sealing member did not relate to a method of performing the invention and, as such, did not need to be disclosed in the specification.
The appeal decision
The Full Court dismissed Sandvik’s appeal in relation to the best method issue.
In the course of its reasoning, the Full Court dug deep into the (scant) case law on best method and set out of the following key principles:
- the purpose of the requirement is to allow the public the full benefit of the invention when the monopoly expires;
- although a patentee might not be explicitly required to act in good faith, principles of good faith underlie the best method requirement;
- the nature and extent of the disclosure required to satisfy the best method requirement will depend on the nature of the invention itself;
- the key to understanding the obligation of the patentee is to understand that Section 40(2)(aa) is directed to the method of performance of the invention. The monopoly is circumscribed by the claims, but the nature of the invention is as described in the whole of the specification; and
- the requirement to describe the best method of performing the invention is ordinarily satisfied by including in the specification a detailed description of one or more preferred embodiments of the invention.
Relying on the inventor’s evidence, the Full Court found that the design of an effective water seal was ‘a critical (rather than a minor or incidental) aspect of the best method of performing the invention’. As such, the Full Court rejected Sandvik’s argument that it was unnecessary to describe the sealing member because it was not part of the claimed invention – the use of an effective water seal was ‘nevertheless necessary and important to perform the invention (or carry it into effect)’.
The Full Court also placed emphasis on the express words and figures of the specification. The Full Court found that the specification purported to set out the best method of performing the invention, including a section headed “Best Modes for Carrying out the Invention” that incorporated a detailed description of two preferred embodiments of the invention. One of these embodiments described a specific sealing member to be used on the preferred version of an adapter in the system, but not the superior sealing member described above. In these circumstances, the Court considered it incumbent on Sandvik to describe the best embodiment known to it.
The Full Court distinguished the present case from Firebelt Pty Ltd v Brambles Australia Ltd (2000) 51 IPR 531 (Firebelt). In that case, the Full Court held that the specification did not need to disclose the detail of the preferred ‘lid opening mechanism’ known to the inventors because the invention was “not of a particular type of lid opening device operating at any particular time”. The Full Court came to this conclusion even though a ‘lid opening device’ was an express feature of claim 1 of the patent in suit but not described in detail in the specification (and as such was disclosed only in the most general terms). The Full Court distinguished the facts in Sandvik because the use of an effective sealing member was necessary and important to carry the extension drilling system disclosed in the patent into effect (which may not have been true of the lid opening mechanism in light of the way it had been described by the Full Court). Further, unlike the patent in Firebelt which did not purport to describe a particular type of lid opening mechanism, the specification put forward (in the drawing of two preferred embodiments) a particular type of sealing member which Sandvik knew not to be the best. It is worthwhile to note that the Full Court went to some length to emphasise that ‘there is a limit to what can usefully be drawn from the factual outcome of another case on an issue such as this. That outcome will necessarily depend on a range of facts and circumstances pertaining to the particular case’.
The Full Court’s decision in Sandvik clarifies that when applying the ‘best method’ requirement, a court will:
- start by identifying the invention described by the specification as a whole, as distinct from the invention as claimed in the claims;
- consider whether the allegedly omitted ‘method’ is necessary and important to perform the invention (or carry it into effect); and
- examine the specification closely to determine whether the specification purports to set out the best method of performing the invention.
It is important to remember though that the outcome of any best method pleading will turn on the facts and circumstances of the case.