Details: The accused infringer argued that Chef America controls (Chef America v. Lamb-Weston, Inc., 358 F.3d 1371 (Fed. Cir. 2004)), so that the court must construe the claim as written and grant summary judgment of non-infringement. The accused infringer further argued that under such a construction, the claim was invalid under § 112 Second and § 101.
The patentee accepted that the plain meaning of "superposed" was "above." Even so, the patentee argued that one of ordinary skill in the art would interpret the claim as referring to one plug above and a different plug below, since the claim contained two references to "a bridge plug."
The district court rejected the patentee's "strained and entirely unpersuasive attempt to reinterpret Claim 4." Having concluded that the claim contained an error, the court then phrased the next issue as whether it had the authority to correct the error by replacing "superposed bridge plug" (i.e., above) with "subjacent bridge plug (i.e., below).
As a threshold matter, the court held it would not correct the error because the patentee had argued in a hearing that the claim did not contain an error. Furthermore, correction is appropriate only when the correction is not subject to reasonable debate – and here reasonable debate existed because the patentee argued "no error."
The court then quickly disposed of the issue of infringement (none – not even possible) and moved on to invalidity. The court found the claim failed to meet both the written description requirement and the requirement under § 112 Second "applicant regards as his invention:"
With Claim 4 written as is, the specification would have to describe a bridge plug that has a lower end capable of engaging another bridge plug located above it. Instead, the specification describes what one would expect to find, namely a bridge plug with an engaging portion at an end that is capable of connecting with another bridge plug positioned adjacent to that end. Because Claim 4 is not described anywhere in the specification (due to the use of "superposed" instead of "subjacent"), it necessarily fails the written description requirement ...
[T]he bridge plug as described in the specification of the '376 Patent differs materially from that described in Claim 4. Thus, due to the use of "superposed" rather than "subjacent," the claim is invalid under paragraph 2 of Section 112.
Since the claim recited an impossible limitation, the court also found that the claim failed to meet the enablement and utility requirements, citing Process Control Corp. v. HydReclaim Corp., 190 F.3d 1350, 1359 (Fed. Cir. 1999):
[W]hen an impossible limitation, such as a nonsensical method of operation, is clearly embodied within the claim, the claimed invention must be held invalid. . . . [W]hen the claimed subject matter is inoperable, the patent may indeed be invalid for failure to meet the utility requirement of § 101 and the enablement requirement of § 112.My two cents: Definitely the right result. Though I do wonder if four grounds for invalidity were overkill.
The court treated as fatal the patentee's refusal to admit error in the claim. But I feel certain that the court would have reached the same result anyway. The facts here seem very close to the burning bread dough in Chef America.
I'd be surprised if the claim at issue was an originally filed claim. Instead, it was probably the result of careless prosecution. I'd say the four lessons here are:
- Proofread your claim amendments.
- Proofread your allowed claims.
- Proofread your issued claims.
- Proofread before filing a lawsuit.
Thanks to Scott Daniels at the Reexamination Alert blog for bringing this case to my attention.