Co-written with Dino Clarizio
This is the third of a series of three posts discussing some of the issues addressed by the trial judge (McVeigh J.) in NCS v Kobold, 2023 FC 1486. The three issues we discuss are those that arise less frequently in patent cases. They are:
Topic 3: Overbreadth
There is controversy in Canada as to whether claims of an issued patent may be held invalid for overbreadth, that is, for claiming more than the inventor actually invented or more than the invention disclosed in the patent. This controversy exists because some argue that the Patent Act is silent as to overbreadth. However, the Supreme Court in the AstraZeneca case (2017 SCC 36) held that “overpromising is a mischief” and as such “[a]n overly broad Claim may be declared invalid.” (para. 45-46) In Seedlings (2021 FCA 154), the Federal Court of Appeal held that, when assessing an overbreadth allegation, the focus is on determining whether a feature “is so key to the invention described in the disclosure” that a claim that omits that feature encompasses embodiments that were not contemplated by the inventor.
In the NCS v Kobold case, NCS and Kobold each alleged that the other’s patents were invalid for overbreadth. Justice McVeigh began her analysis by noting that the jurisprudence provides no specific analytical framework for determining whether a feature of the invention disclosed in the patent is “so key to the invention”, per Seedlings. She suggested that, generally, a claim will be overbroad where it fails to effectively claim an element that is essential to the invention or where the claim element “goes to the very core of the described invention.”
In her decision, Justice McVeigh found it was unnecessary to decide the overbreadth allegations made with respect to four of NCS’s patents (676 Patent, 652 Patent, 907 Patent, and 026 Patent) because she held they were invalid for anticipation and/or obviousness. Moreover, Justice McVeigh also refused to address NCS’s overbreadth allegation against Kobold’s 571 Patent because this allegation was outside the scope of issues defined by the parties’ Joint Statement of Issues.
The only patent for which Justice McVeigh considered allegations of overbreadth was NCS’s 704 Patent, which generally claimed a fracturing valve for fracturing/perforating wellbores. Kobold argued that the claims of the 704 Patent were invalid for overbreadth because each of the claims omitted at least one of the following essential elements of the invention described in the patent: a wedge, a seal, a plug, an alignment mechanism, and holding the mandrel stationary. In assessing this allegation, Justice McVeigh determined whether each element:
- went to the core of the invention; and
- formed part of the common general knowledge of the skilled person.
Kobold argued that each of the claims that did not specify a wedge component was invalid for overbreadth because the invention could not function without it. Justice McVeigh held, from a review of the 704 Patent, that a skilled person would have understood that a solid obstruction component blocking the throughbore of the tubular went to the very core of the invention, but not a wedge specifically. Based on the common general knowledge, she found that the skilled person would have known that a solid component was required and would have read the claims of the 704 Patent as inherently including an obstruction. Therefore, Justice McVeigh held that the claims that did not specify a wedge were not invalid for overbreadth.
The parties agreed that a “lower seal” component was essential for the invention described in the 704 Patent to operate. The issue was whether the claims had to explicitly include a lower seal. NCS argued that, based on a purposive construction of the claims, a lower seal was included by reason of the word “comprising” in the claims. Justice McVeigh disagreed with NCS and held that the skilled person would not have read the claims as including a lower seal despite the claims using the inclusive word “comprising”. Accordingly, the claims requiring (but missing) a lower seal were held to be invalid for overbreadth.
In contrast to the wedge, Justice McVeigh held that the skilled person would have understood that the plug was essential because it went to the very core of the invention. The evidence showed that, although plugs were commonly known, not all fracturing valves included a plug. In other words, Justice McVeigh rejected the argument that the skilled person would have read “fracturing valve” as inherently including a plug. Therefore, the claims that did not specify a plug were invalidated for overbreadth. NCS made an alternative argument that the plug was not an essential element because it was not needed for the invention to work for applications other than fracturing. Justice McVeigh rejected this argument, finding that the 704 Patent disclosure described the invention as being related to fracturing/perforating wellbores.
The Alignment Mechanism:
Justice McVeigh found that an alignment mechanism was also essential as it went to the core of the invention of the 704 Patent. The evidence did not establish, as was argued by NCS, that a skilled person would have read the claims as inherently including an alignment mechanism. Therefore, all claims of the 704 Patent missing this element were invalidated for overbreadth.
Holding the Mandrel Stationary:
Claim 23 of the 704 Patent was a dependent claim that added the limitation that the mandrel be held stationary. This was the only meaningful difference between Claim 23 and earlier independent claims. Kobold argued that the independent claims that lacked this element were invalid for overbreadth.
Justice McVeigh reviewed the disclosure of the 704 Patent and held that the skilled person would have understood that this element went to the core of the invention. Justice McVeigh disagreed with NCS that the limitation recited in dependent Claim 23 could be read into the independent claims for two reasons. First, she found that doing so would violate the presumption of claim differentiation – a presumption that is even stronger when the element at issue is the only meaningful difference between the dependent and independent claims. Second, although the element formed a basic part of the common general knowledge, the skilled person would not have understood the independent claims as including the limitation of dependent Claim 23, as they would have presumed that the inventor intended not to create redundant claims. NCS had not adduced sufficient evidence to rebut the presumption against redundancy of claims. Consequently, Justice McVeigh concluded that the independent claims were invalid for overbreadth since they omitted the essential element of a stationary mandrel.