The 2007 case of The Saunders Group v. Comfortrac is an interesting case for a number of reasons. The patent at issue was a continuation that included claims broader than the claims of its parent patent. The Federal Circuit had to construe the term “pneumatic cylinder” in the child patent. Namely, the court had to determine whether the term pneumatic cylinder, as used in the child patent, was meant to include at least one pressure activated seal. The phrase “pressure activated seal” had been used to further define “pneumatic cylinder” in the claims of the parent patent; but, the phrase “pressure activated seal” had been expressly omitted from some of the claims of the child patent.
Judge Michel first remarked during oral argument that while a continuation application might be appropriate in some situations for pursuing broader claims, it might not be appropriate in every conceivable circumstance. [Listen]
The panel then went on to consider the effect of the Summary of the Invention section of the patent at issue. In the patent at issue, the applicant had referred to “the invention” in the first two sentences and then referred to “embodiments of the invention” in subsequent sentences. The panel quizzed the patentee’s attorney on the significance of that paragraph structure. [Listen]
The exchange above is also interesting because the patentee’s attorney was able to argue that the boilerplate language appearing at the end of the patent was relevant to the meaning of the term at issue.
The court eventually held that the term “pneumatic cylinder” did not require the inclusion of a “pressure activated seal.” Yet, the case is also interesting because the court indicated it might have reached a different decision if the term “pressure activated seal” had been omitted from all of the independent claims of the child patent rather than just some of the claims. The court stated: “When the patentees filed the continuation application, they omitted that limitation [pressure activated seal] from some, but not all, of the new claims. Had they omitted the limitation from all of the claims, it might be argued that the limitation was assumed to be present and did not need to be explicitly recited. Making such a change to only some of the claims, however, is a strong indication that the claims not reciting pressure activated seals were not intended to require them.”
You can read the court’s opinion here [Read]. Again, note that this is a 2007 opinion.