Provisional patent applications (referred to as “provs”) are filed to establish a priority date for an invention. They are, in effect, a draft of a “complete” patent application which must be filed within one year of the prov to maintain the patent pending rights. A complete may expand on the information in the prov and claim the priority date of the prov. However, in order for any claim in the complete to be valid, it must be fairly based on the information in the prov.
The recent Federal Court case of Bradken Resources Pty Ltd v Lynx Engineering Consultants Pty Ltd [2012] FCA 944 illustrates that it is important to include as much information in your prov as possible.
In this case, a key feature of Lynx’s invention was not sufficiently described in the prov. The key feature was claimed in the complete and made the invention novel over the prior art. However, Bradken argued that there was insufficient basis for this key feature in the prov. Justice McKerracher agreed. Accordingly, the main claim of the complete patent was not entitled to claim the priority date of the prov, which was filed one year earlier. Bradken seized on this fact and almost turned it into a disaster for Lynx.
Bradken pointed out that after the prov was filed, but before the complete was filed, Lynx demonstrated the key feature of the invention to BHP. Bradken claimed that Lynx had “secretly used” the invention before the priority date of the complete, which would render the patent invalid. Fortunately for Lynx, BHP had not paid Lynx for the demonstration. Accordingly, Justice McKerracher decided that demonstration of the invention was “experimental use” (which is allowed under the Patents Act), not “secret use”.
Had Lynx adequately described the key feature of the invention in sufficient detail in the prov, Bradken would not have been able to challenge the validity of the claim.
The take home message is to include as much detail in your provisional as possible. This includes a thorough explanation of every aspect of your invention, professionally made drawings of the invention with as much detail as possible and references to any possible variations someone could make of your invention.
Please don’t hesitate to contact us if you have any questions on the above.