In re Buszard (Fed. Cir. 2007)
The Buszard application is directed to a flame retardant composition that includes a flexible polyurethane foam base. The PTO Patent Appeal Board rejected Buszard’s patent application as anticipated by a prior patent.
On appeal, the CAFC reversed — Judge Newman penned the opinion that focused on the PTO’s practice of giving claims their ‘broadest reasonable interpretation.’
“Buszard's specification and claims specifically state the requirement of a flexible polyurethane foam…. No matter how broadly "flexible foam…" is construed, it is not a rigid foam…. The [cited prior art] reference describes only a rigid foam reaction mixture that produces a rigid product. Only by mechanically crushing the rigid product into small particles is it rendered flexible, as a rock can be mechanically crushed to produce particles of sand. This description cannot reasonably be construed to describe, and thus to "anticipate," the flexible foam product of a flexible foam reaction mixture. We agree with Buszard that it is not a reasonable claim interpretation to equate "flexible" with "rigid," or to equate a crushed rigid polyurethane foam with a flexible polyurethane foam.”
Interestingly, Judge Newman’s claim construction intertwines analysis of the claim language with analysis of the scope of prior art disclosure. Although the PTO may give an applicant’s claims broad interpretation — the scope of the prior art cannot extend beyond its disclosure.
Judge Prost dissented. In Prost’s view, any ambiguities in patent claim terms should be construed against the patentee during prosecution of the patent. That approach avoids the usual ‘guessing game’ of Phillips-style claim construction and it is quite easy for an applicant to make clarifying amendments to claim language.