The opinion of the court was delivered by: LIFLAND
W.L. Gore & Associates, Inc. ("Gore") moves for partial summary judgment of noninfringement of Colgate Palmolive Company's ("Colgate's") '488 patent, contending that its beeswax-coated Glide dental floss does not literally infringe the '488 patent and invoking the doctrine of prosecution history estoppel (also known as "file wrapper estoppel") to parry Colgate's assertion of infringement by the doctrine of equivalents. Colgate counters that it surrendered no claim coverage during the prosecution history, or at a minimum, fact questions abound on this question, thereby precluding summary judgment. For the reasons set forth below, the Court holds that Gore has not infringed Colgate's '488 patent.
This is a patent infringement suit brought by Colgate against Gore, both manufacturers of dental floss. Colgate is the owner of United States Patent No. 5,033,488 ("the '488 patent"), which Gore is alleged to have infringed by making, selling, and using wax-coated polytetrafluoroethylene ("PTFE") dental floss.
Colgate's '488 patent discloses a PTFE dental floss coated with microcrystalline wax ("MCW"'). PTFE is a teflon
material that is stronger and has a lower coefficient of friction than linen, cotton, or other floss fibers currently on the market, enabling it to slide more easily in the contact points between teeth. However, the low coefficient of friction renders it difficult to grasp uncoated PTFE floss. Colgate discovered during research that "MCW, surprisingly, adheres to the porous, high strength PTFE," see '488 Patent, col. 2, lines 8-9, increasing the coefficient of friction and making it easier to handle. The patent therefore discloses a floss that uses a wax coating to increase the coefficient of friction, whereas the prior art taught that wax could decrease the floss' coefficient of friction.
Claim 1 of the '488 patent, the only independent claim, describes:
1. A dental cleaning floss wherein said floss is comprised of expanded polytetrafluoroethylene having a tensile strength of at least 68,950 kPa, or polymeric matrix strength of at least 689,000 kPa and a coefficient of friction of at least about 0.08, said coefficient of friction having been increased from untreated polytetrafluoroethylene by having adhered to the surface of said polytetrafluoroethylene a microcrystalline wax having a molecular weight of about 580 to 800.
References to MCW permeate the patent, not only in the claims but also in the background and detailed description sections. The word "beeswax" is nowhere mentioned in the patent.
The '488 patent resulted from Patent Application Serial No. 282,962 ("the '962 application"), itself a continuation in part of application number 174,757.
Claim 1 of the application described: "A dental cleaning floss comprising a multiplicity of filaments of Expanded PTFE, having a tensile strength of at least 68,950 kPa and a polymeric matrix strength of at least 689,600 kPa and a coating adhering thereon of microcrystalline wax, said floss having a coefficient of friction of from about 0.08 to about 0.25." See Pfeffer Decl., Ex. 2 at 28. The patent examiner initially rejected all the claims as obvious in light of the Lorch (U.S. Patent No. 4,776,358) and Guyton (U.S. Patent No. 4,029,113) patents. See id. at 37. See also 35 U.S.C. § 103.
As the Examiner explained in an Action filed February 28, 1990: "Lorch shows PTFE floss, however, does not show a microcrystalline wax coating. Guyton shows a floss coated with microcrystalline wax (column 4, lines 15-20). It would be obvious to one of ordinary skill in the art to modify Lorch to include a wax coating as shown by Guyton because wax coated floss is well known in the dental floss art. The range of coefficient of friction of the floss is held to be an obvious matter of choice in the range of known parameters because the reason wax is used with dental floss is to decrease the friction when in use." See Fier Decl., Ex. B at 2-3. (emphasis added). Thus, the examiner seems to have construed the wax coating as being used for its traditional purpose, essentially to reduce the coefficient of friction.
Colgate responded with an amendment filed on May 7, 1990, cancelling original claim 1 and substituting claim 10, which became claim 1 of the '488 patent. The only added limitation between the prior and amended version was the 580-800 parameter placed on the molecular weight of the microcrystalline wax. The other change, which did not limit the claim's scope, was the explicit statement that MCW is utilized to increase the coefficient of friction: "said coefficient of friction having been increased from untreated polytetrafluoroethylene by having adhered to the surface...a microcrystalline wax...." '488 Patent, Claim 1. Accompanying the amendment was argument that explained why the prior art Lorch and Guyton patents did not anticipate Colgate's claims.
Summary judgment is not a disfavored procedural shortcut, but rather an essential thread in the fabric of the Federal Rules that eliminates unfounded claims without recourse to a costly and lengthy trial. See Celotex Corp. v. Catrett, 477 U.S. 317, 327, 91 L. Ed. 2d 265, 106 S. Ct. 2548 (1986). Summary judgment is appropriate only "if the pleadings, depositions, answers to interrogatories, and admissions on file, together with the affidavits, if any, show that there is no genuine issue as to any material fact and that the moving party is entitled to a judgment as a matter of law. " Fed. R. Civ. P. 56(c). The burden of showing that no genuine issue of material fact exists rests initially on the moving party. See Goodman v. Mead Johnson & Co., 534 F.2d 566, 573 (3d Cir. 1976), cert. denied, 429 U.S. 1038, 50 L. Ed. 2d 748, 97 S. Ct. 732 (1977). "This burden...may be discharged by 'showing'...that there is an absence of evidence to support the nonmoving party's case." Celotex ...