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June 30, 2006

Prosecution Estoppel Aide

Momentus Golf sued Swingrite Golf for infringing 5,582,407, a "golf club swing aide." Swingrite swung a district court summary judgment of non-infringement based on prosecution estoppel which narrowed claim scope. Momentus drove to the appeals court (CAFC 05-1614), which gave the district court a mulligan.

The issue in this case is whether, during the prosecution of the ‘407 patent, the applicant disclaimed devices having a club head weight of more than 10%. The purpose of the doctrine of prosecution disclaimer is to prevent a patentee from recapturing through claim interpretation meanings he disclaimed during prosecution. SanDisk Corp. v. Memorex Prods., Inc., 415 F.3d 1278, 1286 (Fed. Cir. 2005) (citations omitted). Any such disclaimer must be clear and unmistakable. Id. (stating “[w]hen the patentee makes clear and unmistakable prosecution arguments limiting the meaning of a claim term in order to overcome a rejection, the courts limit the relevant claim term to exclude the disclaimed matter” (citing Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1324 (Fed. Cir. 2003))). We have explained, however, that “[t]here is no ‘clear and unmistakable’ disclaimer if a prosecution argument is subject to more than one reasonable interpretation, one of which is consistent with a proffered meaning of the disputed term.” Id. at 1287 (citing Golight, Inc. v. Wal-Mart Stores, Inc., 355 F.3d 1327, 1332 (Fed. Cir. 2004)); Cordis Corp. v. Medronic Ave, Inc., 339 F.3d 1352, 1359 (Fed. Cir. 2003) (finding no disclaimer because “the statements in the prosecution history are subject to multiple reasonable interpretations, they do not constitute a clear and unmistakable departure from the ordinary meaning of the term [at issue]”).

The '407 prosecutor overcame a rejection via 3,231,281 (Wallo), by explaining that Wallo had a hollow shaft, and that "A hollow device having 10-25% club head weight cannot meet the requirement in applicant’s claims that the center of gravity of the trainer be substantially at the center of a solid round stock."

Because the claimed invention could not be distinguished from Wallo solely on the grounds of being solid, the district court interpreted the underlined sentence above as identifying another distinction between the claimed invention and Wallo; namely, club head weight. Based on this, the court viewed the statement as a “conce[ssion] that the device with a club head having 10-25 percent of its weight at the end of the shaft opposite the grip would fall outside the scope of the [claimed] trainer.” Claim Construction Order at 1143. This reading is fathomable. However, we agree with Momentus that this sentence is open to another interpretation: the applicant was simply stating that a hollow club having 10-25% club head weight (a device described by Wallo) could not meet the claim limitation in the ‘407 patent that the club shaft have a center of gravity at the center of a solid shaft. Such a reading does not suggest that all clubs having a 10-25% club head weight are outside the scope of the invention; rather, only hollow clubs with such a characteristic fall outside the scope of the claims.

Interpreting the prosecution history in this manner does not affect the applicant’s argument that the claimed invention was not anticipated by, or obvious in view of, Wallo. The applicant of the ‘407 patent distinguished the claimed invention from Wallo on grounds other than “solidness”; namely, that the two devices functioned in totally different ways.

We conclude that the statement in the prosecution history that “[a] hollow device having 10-25% club head weight cannot meet the requirement in applicant’s claims that the center of gravity of the trainer be substantially at the center of a solid round stock,” (emphasis added), is open to more than one reasonable interpretation. Thus the statement was not a clear and unmistakable disclaimer of all devices having 10-25% club head weight. See SanDisk, 415 F.3d at 1287; Cordis, 339 F.3d at 1359. At most it disclaims hollow devices having 10-25% club head weight.

The majority opinion is thus that prosecution estoppel must be construed in context, with regard to specifics, as to what has been disclaimed.

Vacated and remanded.

Judge Schall dissented, because, as he put it: "I am unable to read the passage as the majority reads it," thus agreeing with the district court ruling.

I read the underlined sentence of the passage as clearly and unmistakably disclaiming both (i) a device having 10-25% club head weight and also (ii) a device having a hollow shaft.

Posted by Patent Hawk at June 30, 2006 12:20 PM | Claim Construction


Hal Wegner on this case -

In today’s split decision in Momentus Golf, Inc. v. Swingrite Golf Corp., __ Fed.App.__ (Fed. Cir. 2006)(Archer, J.)(attached), three judges with cumulatively forty years of experience on the Federal Circuit were unable to agree on a simple claim construction issue, thanks to the complex claim construction regime that creates a basis to narrow the literal scope of protection based upon statements in the prosecution history. A cogent dissent manifests how difficult it is even for a panel averaging thirteen (13) years on the appellate bench, eating, living and breathing patent law, to "get it right" under the American system. Momentus Golf, __ Fed.App. at __ (Schall, J., dissenting). A fortiori, think of the trial judge experiencing his first or second patent case.

In a comparative review of claim interpretation principles, the House of Lords in Kirin-Amgen Inc. v. Hoechst Marion Roussel, [2004] UKHL 46 (2004), denied this internationally odd American approach (excerpted below). The United States, itself, never had a doctrine of "prosecution disclaimer"—as in Momentus Golf – until the doctrine was judicially created by the Federal Circuit just over twenty years ago.

It is time to rethink the American claim construction model.


Lord Hoffmann in Kirin-Amgen on Claim Construction:

"The courts of the United Kingdom, the Netherlands and Germany certainly discourage, if they do not actually prohibit, use of the patent office file [wrapper] in aid of [claim] construction. There are good reasons: the meaning of the patent should not change according to whether or not the person skilled in the art has access to the file and in any case life is too short for the limited assistance which it can provide. It is however frequently impossible to know without access, not merely to the file but to the private thoughts of the patentee and his advisors as well, what the reason was for some apparently inexplicable limitation in the extent of the monopoly claimed. One possible explanation is that it does not represent what the patentee really meant to say. But another is that he did mean it, for reasons of his own; such as wanting to avoid arguments with the examiners over enablement or prior art and have his patent granted as soon as possible. This feature of the practical life of a patent agent reduces the scope for a conclusion that the patentee could not have meant what the words appear to be saying. It has been suggested that in the absence of any explanation for a restriction in the extent of protection claimed, it should be presumed that there was some good reason between the patentee and the patent office. I do not think that it is sensible to have presumptions about what people must be taken to have meant but a conclusion that they have departed from conventional usage obviously needs some rational basis."

Posted by: Patent Hawk at June 30, 2006 12:27 PM

Hal Wegner's comment prompts the observation how fiendishly difficult it is to do something piecemeal to remedy a fundamentally flawed but long-standing system. Doing something to bring clarity on one legal issue disturbs the law in other areas. In contrast, how lucky Europe is, to have a patent law from 1978 that was a fresh start for all member States, that corrected all the deficiencies in UK law that the German expert academics could find, and vice versa. Neither country was powerful enough to impose its pet solutions on the other. Common law UK had to defer to civil law mainland Europe, and vice versa. The EPC contains all necessary legal provisions, but nothing more than the necessary.

The EPO goes to great pains, before issue, to force Applicants to conform the specification to the allowable claims. Courts in Europe don't want to see, and don't need to see, the PTO file wrapper.

Posted by: MaxDrei at July 1, 2006 4:31 AM