Wagner sounds a cautionary note for inventors

The recent High Court decision, published on 18 April, in the patent dispute Wagner International AG & others v Earlex Limited has provided a useful reminder about the risks run by inventors of displaying and demonstrating their inventions to the public at trade shows and exhibitions.

The case concerned a claim for patent infringement made by a number of Wagner group companies against Earlex Limited in relation to Wagner`s patent for an air gun for paint spraying. The allegations of infringement centred around the inclusion and positioning of "venting holes" in the base of the spray gun which formed part of the claims of Wagner`s patent.

Amongst other issues, the Court was asked by Earlex`s legal team to find that in fact the Wagner patent was invalid for "obviousness."

One of the tests for the patentability of an invention is that it involves an "inventive step." Section 3 of the Patents Act 1977 says:

"An invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art by virtue only of section 2(2) above."

Section 2(2) referred to defines the "state of the art" as:

"…all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way."

As a starting point, in the UK the "priority date" of an invention will be date at which a patent application has been filed. However, an earlier priority date can sometimes be claimed by reference to an earlier "parent" patent application.

Part of the evidence that Earlex relied upon was to show that in March 1991, before the priority date of their patent, Wagner had exhibited their "FineCoat" spray gun, which used the technology in question, at the HomeCenter trade show in Chicago. Moreover, they had allowed members of the public visiting their stand to examine the gun closely and even to use it.

The Judge, Mr Justice Floyd, concluded based on cross examination of expert evidence, that a skilled person who visited the Wagner trade stand and examined and used the FineCoat gun would be able to understand its construction, including the venting holes, and would then be able to go home and reproduce it "in their shed" (that great bastion of British engineering and inventiveness!), and that therefore the relevant claims of the patent that were being relied upon against Earlex were invalid for obviousness. As a result, any question of whether or not the Earlex product infringed those claims became irrelevant and Wagner`s claim failed.

This case is a useful reminder to inventors who are naturally keen to display and demonstrate their new and potentially patentable inventions to potential buyers whether at trade shows (as in this case) or by taking it around to meet the potential buyers and investors at their premises.

Probably the two best pieces of advice to inventors in these circumstances are firstly to consider whether they really need to exhibit/demonstrate their invention at this stage, before securing a priority date for any potential patent. Secondly, and assuming that commercial pressures mean that they do feel the need to do this, then the inventor should take care to ensure that by doing so he does not invalidate his potential patent by inadvertently making his invention part of the "state of the art." Bearing in mind that the definition of this requires "matter…that has been made available to the public" then the best way to ensure this would be to show the invention only to those people who have signed a tightly-drawn confidentiality agreement, defining and limiting the purposes for which the invention is being disclosed to them. Exhibitor staff at a trade show can be provided with a supply of such agreements for potential commercial partners to sign, and it would also be advisable for any potentially patentable products which are subject to such an agreement to only be on show and/or demonstrated in a closed area of your trade stand, not accessible or visible to the public at large, or perhaps by prior arrangement in a private meeting room at the venue.

Inventors and their employers would be well advised to seek advice both from a patent agent and a solicitor before attempting to take any potentially patentable invention "on the road" and in doing so running the risk of "creating their own prior art."

This article is for general guidance only. It provides useful information in a concise form. Action should not be taken without obtaining specific legal advice.