Anticipate This!™ | Patent and Trademark Law Blog

Welker Bearing Co. v. Phd Inc.

Posted in Opinion Commentary by Jake Ward on January 4, 2009

The generic terms “mechanism,” “means,” “element,” and “device,” do not connote sufficiently definite structure to avoid means-plus-function treatment.

(Fed. Cir. 2008, 08-1169)


The U.S. District Court (E.D. Virginia) granted summary judgment of noninfringement of Welker Bearing Co.’s U.S. Patent Nos. 6,786,478 (“’478 patent”) and 6,913,254 (“’254 patent”) in favor of PHD, Inc.  The CAFC affirmed the summary judgment, stating that the district court correctly construed the critical claim element of the ’254 patent as a means-plus-function limitation subject to 35 U.S.C. § 112 ¶ 6.

The technology of the Welker patents relates to locating pins for inserting into a work piece to position and hold the work piece on an assembly line.  Specifically, Welker claimed pin clamps that hold a work piece securely in place during welding and other manufacturing processes.  The critical claim language was the phrase “said assembly characterized by a mechanism for moving said finger along a straight line into and out of said locating pin perpendicular to said axis A in response to said rectilinear movement of said locating pin”.  In determining that PHD did not infringe Welker’s patents, the district court construed a “mechanism for moving said finger” limitation in the claims as a means-plus-function limitation subject to 35 U.S.C. § 112 ¶ 6. 

“Means-plus-function claiming applies only to purely functional limitations that do not provide the structure that performs the recited function.” Phillips v. AWH Corp., 415 F.3d at 1311 (Fed. Cir. 2005).  Further, a patentee’s use of the word “means” in a claim limitation creates a presumption that 35 U.S.C. § 112 paragraph 6 applies. TriMed, Inc. v. Stryker Corp., 514 F.3d 1256, 1259 (Fed. Cir. 2008).   The use of means-plus-function language requires an identification of “the corresponding structure, material, or acts described in the specification and equivalents thereof.” 35 U.S.C. § 112 ¶ 6. 

The CAFC noted that the term “mechanism” standing alone connotes no more structure than the term ‘means.’”  No adjective endowed the claimed “mechanism” with a physical or structural component.  Further, the claims at issue provided no structural context for determining the characteristics of the “mechanism” other than to describe its function.  The court also held that the unadorned term “mechanism” is “simply a nonce word or a verbal construct that is not recognized as the name of structure and is simply a substitute for the term ‘means for.’” Accordingly, the CAFC agreed that the district court properly applied means-plus-function treatment to the term “mechanism”.


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