The Federal Court of Appeal upheld the dismissal of an appeal from a Re-examination Board which had considered Canadian Patent 2,421,384 and had determined that claims 12-14 were cancelled because they were obvious in light of newly presented prior art and the common general knowledge of a person of ordinary skill in the art.

The reviews by both levels of the Federal Court and by the Re-examination Board turned, to some large degree, not just on the obviousness of the concept (that waste heat from an internal combustion engine could be used to heat fluid in a tank associated with an oil well), but also that there was a need for a more efficient manner of heating such a tank, instead of the prior art method of burning propane in a fire tube through the tank to heat its contents. Appellant (patentee) argued that the concept was obvious only if the need itself was identified. Thus, in the Appellant's view, identification of the need was not in the prior art, and was inventive and non-obvious.

The identification of a requirement for efficiency was, all levels of review determined, found in a statement made by the patentee in the specification that there was a need for more efficient heating. The statement referred to was to the effect that the current production tank heating method was inefficient, and that the concept of the invention proposed a solution.

Not a surprising conclusion, EXCEPT that the statement in question was contained in the portion of the specification referred to as the SUMMARY OF INVENTION.

Ordinarily, patent drafters consider materials in the Summary of the Invention section of patent documents to describe new subject matter, the concepts of the invention, and do not expect this section to be cited as an admission of the state of the prior art. In this case, the trial judge ruled that it was reasonable for the Board to consider the information found under the SUMMARY OF THE INVENTION heading, to be part of the background knowledge which the skilled person would have.

This case should be viewed as a cautionary note to patent drafters that courts may choose to ignore headings when construing patents, and may refrain from elevating form over substance (per Mr. Justice Mosely at 2014FC287, p.16). Patent drafters should therefore be fastidious when making statements regarding the state of the art and any perceived shortcomings which may be addressed by the invention.