Patent Re-examination in Canada: Court Takes Truck Argument Off the Road

February 5, 2020
By Noel Courage

A recent article from our firm discussed processes for challenging a competitor’s granted Canadian patent rights. The Federal Court of Canada recently provided a good example of a successful post-grant challenge in Cusitar v Canada 2019 FC 1641. The patent was invalidated as obvious during re-examination at the Canadian Patent Office. The decision was upheld on appeal to the Federal Court1.

The case began with the inventor filing a patent application on January 5, 2015 for a process for an improved oil sand mining and haulage method2. This patent no. 2,876,770 (“the Patent”) issued on November 8, 2016. A key prior art document during prosecution was patent no. 2,567,644 (issued long before, in 2007) which was referred to as reference “D1”. Reference D1 described an oil sands mining and haulage method using conveyor belts. The Examiner took the position that the Patent overlapped with D1 with the primary exception of conveyor belts being substituted for haulage trucks. The Examiner did not consider a mere substitution of a fleet of haulage trucks for the conveyor belt element of D1 as inventive. The inventor responded arguing that due to the nature of the industry, prior patents, such as D1, would not be used with trucks instead of conveyors for certain steps. He also argued there were more changes than just the use of trucks. The Examiner was satisfied by these comments and eventually allowed the Patent to proceed to grant.   


Filing of Prior Art Against Pending Patent Application

Shortly before the Patent issued, a law firm submitted four prior art documents on behalf of its anonymous client, along with a statement of pertinency of the prior art. This type of third-party submission process against a pending application is generally discussed in this article here. The submission argued that the Patent was obvious because it “has long been well known in the oil sands mining industry (and other mining industries) that conveyors and haul trucks can be used interchangeably to transport mined ore”. The Examiner did not respond to these comments, and allowed the Patent to proceed to grant uninterrupted.


Re-examination Threshold – Substantial New Question of Patentability

A couple of months after grant, the same law firm requested re-examination of the Patent. This request provided 8 documents, four that were previously submitted to the Examiner, and four new ones.

Upon receipt of the re-examination request, CIPO was required to establish a three member re-examination board to assess whether the prior art and comments in the re-examination raised a substantial new question of patentability. This threshold must be met to trigger a full re-examination proceeding. 

The Board was free to consider other prior art in addition to that filed with the re-examination application. As such, D1 was back in play again, in addition to the references provided with the re-examination request. The Board combined reference D1 and several others to find that the re-examination threshold was met, because there was a substantial new question with respect to obviousness. It is an important practice point to note that re-examination requires a new question of patentability, not entirely new prior art documents.


The Substantive Re-examination

The inventor argued during re-examination that his invention was not just about equipment, but rather it was a process flowsheet to increase reliability, availability, productivity and costs. The inventor had an option to amend his claims, but it does not appear that he did so. 

The Board went through the inventor’s written submissions and provided a preliminary opinion which found that each of the steps was either already in the prior art, or would have been obvious to a person of skill in the art. This preliminary opinion also indicated that there had been no evidence of inventiveness based on an industry bias against his oil sands methods (i.e. no evidence that the prior art effectively taught away from his invention). The inventor filed further written arguments and appeared before the Board in person to make a presentation with further oral arguments.

The re-examination decision ultimately concluded with a certificate that cancelled all 15 claims of the Patent based on obviousness over D1, as well as another prior art reference, and the common general knowledge in the art. This cancellation was put on hold pending the appeal to Federal Court.

On appeal, the inventor asked that the re-examination certificate be set aside and claims 1-15 be confirmed as patentable. The inventor also brought a motion in Court to present new evidence about ‘battery limits’ on appeal. The Court rejected the request for new evidence because the evidence could have been previously put before the Board3

The Court refused to revisit the threshold decision of whether there was a substantial new question of patentability. This threshold question is not appealable.

The standard of review of the Board’s decision on patentability was reasonableness. Thus, deference was owed to the Board — that is, the Board decision stands as long as it is “reasonable”. This standard makes for a difficult case for the inventor to win. The Court ultimately agreed with the Board that the inventor had not shown an inventive concept. The decision that the Patent was obvious was found reasonable, and the Patent held invalid4.

This case provides a good illustration of the Canadian re-examination process. Re-examination is best used only to challenge patents where there is a very strong prior art basis. Although this case did not appear to be straightforward, it worked out for the challenger. The challenger does take a risk by filing a re-examination application rather than proceeding with invalidity litigation, because the challenger is not permitted to participate in the proceeding after filing the re-examination application (i.e. the inventor gets to make arguments to CIPO without counter-arguments from the third party). If budget permits, a court action for a declaration of invalidity provides the challenger a fuller opportunity to advocate against the patent and bring more types of evidence forward.

1 It appears that no appeal was filed to the Federal Court of Appeal.

2 The Patent Re-examination Board summarized claim 1 as follows:

  • Mining oil sands with an excavator means;
  • Receiving and storing said mined oil sands in a surge hopper means;
  • Reclaiming said oil sands with a reclaiming conveyance means;
  • Crushing said oil sands in a primary crusher means;
  • Discharging said primary crushed oil sands onto a discharging conveyance means;
  • Operating a tramp metal sensing and alarm means;
  • Transporting said primary crushed oil sands using mine haulage trucks to a slurry preparation facility;
  • Dumping said primary crushed oil sands into a remote surge bin at the slurry preparation facility;
  • Reclaiming said oil sands from said surge bin using conveyance means to feed said oil sands to the adjacent slurry preparation facility
3 The inventor was told in the preliminary opinion that the Board was lacking evidence of a systemic industry practice as to ‘battery limits’.

4 The Board’s lack of discussion of the Examiner’s prior reasons favouring patentability did not render the decision unreasonable.

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