Monday, December 11, 2023

Redundancy between Overbreadth and Utility

NCS Multistage Inc v Kobold Corporation 2023 FC 1486 McVeigh J

2,693,676 / 2,820,652 / 2,738,907 / 2,766,026 / 2,820,704 (NCS) / 3,027,571 (Kobold)

My last post provided an overview of this decision and address several miscellaneous issues. This post addresses the overbreadth argument. McVeigh J held a number of claims of the 704 patent to be invalid for overbreadth. I have argued that overbreath in Canadian law is almost always redundant with some other ground of invalidity. In this case, McVeigh J held most of the overbroad claims to also be invalid for lack of utility, and I will argue that overbreadth was indeed redundant. The details are interesting to see how the two separate tests for overbreadth and utility ended up functionally converging, and to see why some claims were overbroad but nonetheless useful.

The key question on overbreadth is whether a feature of the invention is essential, not in the sense of claim construction, but “whether that feature is so key to the invention described in the disclosure that a Claim that omits it encompasses embodiments that were not contemplated in the disclosure”: Seedlings 2021 FCA 154 [54], quoted at [167]. McVeigh J summarized this as asking whether the whether the feature in question is “at the core of the invention actually invented or disclosed” [1458]. This strikes me as a good summary of Seedlings, which puts the question in a positive form. In utility, the question is whether the invention is useful, which in this case boiled down to whether it was operable, ie whether it worked. In principle, these are two distinct questions. But what does it mean to ask whether the feature lies “at the core of the invention”?

To see how McVeigh J answered this question, we need to turn to the facts. There were five features implicated in the overbreadth and utility attacks, namely three components of the fracturing valve — the wedge, plug, and seal — as well as the the alignment mechanism and the means for holding the mandrel stationary. We can ignore the wedge, as both attacks failed.


On overbreadth, McVeigh J held as follows:

[1467] The placement of the seals and the number of seals goes to the very core of the 704 Patent invention. The 704 Patent discloses a fracturing valve and both parties agree that the lower seal is essential to allow the fracturing valve to operate as disclosed. The 704 Patent does not disclose any method by which the invention could operate without the described lower seal placement. The lower seal is an essential element that goes to the very core of the invention.

The claims that did not specify a seal were therefore invalid for overbreadth [1470]. That means that those claims were overbroad because they were inoperable. The claims without seals were also invalid for lack of utility [1514] for the same reason: “There are no operable embodiments of the 704 Patent Claims that do not include a seal” [1511]. It is not just that the claims happened to be invalid on both grounds: they were invalid on both grounds for the same reason, namely inoperability. Thus overbreadth was functionally redundant in light of the utility requirement.

(Note that Claim 15 was listed as being invalid for overbreadth [1470] but not lack of utility [1514], but in light of McVeigh J’s reasoning, I think this must have been an inadvertent omission from the utility list.)

Equalization Valve or Plug

The equalization plug “goes to the very core of the invention, such that the fracturing valve cannot operate without an equalization plug” [1475]. Again, it is “core” because it is necessary for operability. Consequently, “those claims that do not explicitly claim an equalization plug are invalid for overbreadth” [1478]. Those claims were invalid for lack of utility for the same reason: “the 704 Patent Claims that do not claim an equalization plug cannot perform the claimed fracturing function; they will not operate” [1517]. Again, overbreadth and the lack of utility are functionally the same — both turn on inoperabilty — and the overbreadth attack is redundant.

Alignment Mechanism

Similarly, McVeigh J found that the alignment mechanism goes to the core of the invention because it was necessary for the tool to work [1483], and the claims at issue lacked utility for exactly the same reason [1520]. Again, overbreadth was functionally redundant.

(In the listing of invalid claims at [1486], [1521] claims 24–27 were listed as being invalid for overbreadth but not lack of utility. In light of the reasoning, this seems to have been an oversight.)

Stationary Mandrel

McVeigh J found that a component for holding the mandrel stationary was core to the invention because “there must be some kind of component that provides frictional resistance against the wellbore that allows the mandrel to remain stationary for the invention to operate” [1494]. Claims that did not specify a means for holding the mandrel stationary were therefore invalid for overbreadth [1495].

However, lack of utility was not proven:

[1525] There was insufficient evidence on this issue to demonstrate that the 704 Patent will not work where the mandrel is not held stationary. This is likely due to the fact that Kobold raised this issue in construction and it was not argued substantively by either party in closing.

[1526] Therefore, without more evidence on this specific issue, I find that Kobold has not met its burden to demonstrate inutility on this issue.

So, in discussing overbreadth, McVeigh J found that the tool would not operate if the mandrel was not held stationary, but in discussing utility she could not arrive at that conclusion on the evidence. It is not clear to me why the evidence that McVeigh J relied on in the overbreadth context did not allow her to come to the same conclusion in respect of lack of utility. Nonetheless, it is clear that the functional question was the same under both overbreadth and utility — would the invention work if the mandrel was not held stationary — and the only difference was in respect of the evidence.

In summary, notwithstanding that McVeigh applied separate analyses with separate tests for overbreadth and utility, overbreadth is functionally redundant in light of the utility requirement. I would expect similar results in contexts where there is overlap with novelty or anticipation: eg it seems very reasonable to say that a feature that is the only point of distinction between the prior art and the claimed invention would be considered “core” to the invention.

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