“Obvious to Try” in the Mechanical Context

Wenzel Downhole Tools Ltd v National-Oilwell Canada Ltd 2011 FC 1323, 98 CPR(4th) 155, Snider J

While Snider J’s obviousness analysis in Wenzel is generally fairly routine, there are a couple of interesting points. One is that she invokes the “obvious to try” test in the context of a mechanical invention, saying “[a]n ‘obvious to try’ analysis is clearly warranted here” [197]. This is unusual, because the doctrine is usually thought to be relevant primarily "[i]n areas of endeavour where advances are often won by experimentation", such as chiral chemistry: Sanofi 2008 SCC 61, [68]. The obvious to try analysis addresses a situation where an approach is obvious to try, but success cannot be predicted without an actual trial: see here and here. It seems to be generally the case that in the mechanical arts, success prior to a trial is more predictable, and an obvious to try analysis is accordingly rare. And indeed, I’m not sure Wenzel is really an exception to that rule. While Snider J expressly invokes an “obvious to try” analysis, she makes no reference to the unpredictability of success prior to trial, or the difficulty of achieving success. It strikes me that the actual analysis in which Snider J concludes that the invention is obvious [198-204], would have been exactly the same even without invoking the “obvious to try” question. Her reference to “obvious to try” really only asks “was the invention more or less self-evident?” [197], which is much the same as simply asking “was the invention obvious?”

A second (unrelated) point, is relevant to the long-standing debate over whether the focus on the obviousness inquiry should be the inventive concept, or the claims as construed. While Windsurfing [1985] RPC 59 itself referred to identification of “the inventive concept embodied in the patent in suit,” Pozzoli [2007] EWCA Civ 588 [23] modified this step to “Identify the inventive concept of the claim in question or if that cannot readily be done, construe it.” Hughes J has suggested that it is wrong to focus on the inventive concept because “The claim or claims at issue, as construed by the Court is what are at issue. The "invention" as generally expressed in the patent or by the inventors is not the issue, it is the claim as properly construed” (Janssen-Ortho / levofloxacin 2006 FC 1234 [113.1]). Snider J herself has previously said that “it appears to me that the assessment must be focused on the "inventive concept of the claim in question" and not to some larger "invention" that might be described in the specification of the patent” (Sanofi-Aventis / ramipril, 2009 FC 676, [267]). In this case however, Snider J had no difficulty identifying the inventive concept of the patent generally: “The inventive step of the ‘630 Patent, in my view, was Bill Wenzel’s placement of one or more bi-directional thrust bearings into a single containment chamber with shoulders placed within the chamber such that the same bearings could handle both off-bottom and on-bottom loads during a drilling operation" [175]. Nothing in the case turned on the point, but it does illustrate that despite the arguments for focusing on the claim rather than the inventive concept, or at least focusing on the inventive concept of the particualr claim at issue, there are cases where the Windsurfing route of assessing the inventive concept of the patent as a whole, remains easy and convenient.