Canada’s laws provide a one-year grace period for public disclosures by the applicant (or by a person who obtained knowledge of an invention from the applicant) calculated from the Canadian filing date. The particulars of Canada’s grace period are detailed in our article “Public disclosures of inventions – what you need to know about Canada’s grace period.” In a recent line of cases centered in the Alberta oil sands, Canada’s courts have considered what constitutes public disclosure of an invention by the inventor, which would trigger the start of the grace period.

The Supreme Court of Canada, in Apotex v Sanofi-Synthelabo Canada, 2008 SCC 61, held that “disclosure” of an invention can be established by, among other things, prior use of the claimed invention in public. To establish prior use in public, it is necessary to show that the invention was “available” to at least one member of the public under no obligation of confidentiality. While a plain reading suggests that an invention that is hidden from view or whose inner workings are inaccessible when publicly used would not be “available” to the public, in two recent decisions, the Federal Court has considered additional factors in reaching differing conclusions when faced with such indicia.

In Wenzel Downhole Tools Ltd v National-Oilwell Canada Ltd, 2012 FCA 333, the plaintiff invented a drill apparatus which was rented out to customers more than one year prior to the plaintiff filing a patent application. During rental periods, the drill was encased in a box, and was not visible or easily accessible to renters. Additional information on the invention was available to renters upon request, but no request was received. Even with no evidence that the inner workings of the drill apparatus had been seen, or that the additional information relating thereto had been accessed, the trial and appeal judges found that the renters had an “opportunity to access” that was not circumscribed or prohibited by agreement. The trial and appeal judges decided that opportunity was sufficient to constitute disclosure of the invention, and held the patent invalid.

A different result was reached in similar circumstances in Varco Canada Ltd v Pason Systems Corp (“Varco”), 2013 FC 750. In Varco, a prototype of the plaintiff’s drilling apparatus was used on a third party’s oil rig more than one year before the filing date of a patent application. The inventor testified that he only explained the invention to the rig’s operators in very general terms, and that he personally performed all test drilling. When not in use, the box containing the drilling apparatus was locked, and it was not possible to see inside or otherwise access the invention’s inner workings. Phelan J. of the Federal Court Trial Division found that these facts were consistent with an intent to keep the invention confidential, notwithstanding the absence of a confidentiality agreement, and that the use did not constitute an enabling public disclosure. The patent was held to be valid and infringed.

The above cases do not evince any general proposition regarding the public use of inventions which are not visible or are inaccessible. Rather, the meaning of “available” to the public is a fact-dependent question and must be assessed on a case-by-case basis. Accordingly, the owner or inventor of an invention may not be able to rely on the mere fact that an invention’s inner workings are not visible or are inaccessible to preserve its confidentiality during periods of public use. In cases where some public use of an invention is unavoidable prior to the Canadian filing date of a patent application, conducting such use under written obligations of confidentiality signed by all participants may provide the applicant with some assistance if faced with a validity challenge. Regardless, following an instance of public use with a promptly filed patent application in Canada is the safer route.