Opinion ID: 210676
Heading Depth: 3
Heading Rank: 1

Heading: Curved shank

Text: 20 The main dispute between the parties on construction relates to the claim requirement of a curved shank, construed by the district court to mean a shank that has a bend or deviation from a straight line without sharp corners or sharp angles. Stryker challenges that interpretation, arguing that the better reading of the term is a nonangular continuous bend. When construing claims, a court must begin by look[ing] to the words of the claims themselves . . . to define the scope of the patented invention. Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir.2005) ( en banc ) (quoting Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed.Cir.1996)). The task of comprehending those words is not always a difficult one. In some cases, the ordinary meaning of claim language as understood by a person of skill in the art may be readily apparent even to lay judges, and claim construction in such cases involves little more than the application of the widely accepted meaning of commonly understood words. Id. at 1314. [C]urved, as it is used in the '444 patent, is not a term [] that ha[s] a particular meaning in a field of art. Id. Its ordinary meaning encompasses curvature made up of small discontinuities. Consider, for instance, an archway made from rectangular bricks. The bricks are at angles with respect to each other, but the overall effect is to describe an arc. It would be unreasonable to say that such an archway is not curved. If the word curved is given its ordinary, lay meaning, the district court's construction is correct. 21 Stryker argues that curved is implicitly assigned a different, narrower meaning by virtue of the context in the written description in which it appears. See id. at 1316 ([T]he specification may reveal a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess. In such cases, the inventor's lexicography governs.). That argument is based on a particular manner of implanting the nail disclosed and touted by the written description. The '444 patent's Summary of the Invention section states that [t]he curved tapered shape of the present invention permits it to be inserted into a cavity formed by a broach tool having the same shape as the nail. '444 patent col.1 ll.49-51. A broach tool is essentially a rasp having the same profile as the hole it is intended to form. Id. col.3 ll.27-28. The patent teaches that broaching is advantageous, since, inter alia, it generally causes less tissue damage than a rotating drill bit or reamer. Id. col.3 ll.32-33. However, [b]roaching is only suitable for certain shapes of holes and objects—in particular, it is useful only for an object that largely pass[es] through its own envelope. Id. col.3 ll.37-40. Objects with angled bends or small radius curves (relative to the object length) do not pass through their own envelope on insertion, and are not well suited to insertion into a broached hole. Id. col.3 ll.45-48. 22 Stryker's argument is essentially an assertion that since the patent says broaching is desirable, the term curved must be construed to cover only embodiments whose curvature allows them to be inserted into a broached hole, excluding angled bends or small radius curves. That assertion is flawed: it is an attempt to import a feature from a preferred embodiment into the claims. See Phillips, 415 F.3d at 1323 ([A]lthough the specification often describes very specific embodiments of the invention, we have repeatedly warned against confining the claims to those embodiments.). Neither use with a broaching tool nor suitability for such use is claimed. Indeed, the application which led to the '444 patent originally included claims to the method of implanting the nail with a broaching tool, but the patentee elected to withdraw those claims from the application after the Examiner noted they were directed to a separate, distinct invention. 23 The fact that usability with a broaching tool is merely a feature of a preferred embodiment provides sufficient grounds for refusing to read curved narrowly. We also note, though, that the patent's Claim 13 (not asserted by Acumed in this case) covers [t]he nail of claim 1 having a profile that substantially passes within its own envelope. '444 patent col.6 ll.26-27. [T]he presence of a dependent claim that adds a particular limitation raises a presumption that the limitation in question is not found in the independent claim. Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 910 (Fed.Cir.2004); see also Wengner Mfg., Inc. v. Coating Mach. Sys., Inc., 239 F.3d 1225, 1234 (Fed.Cir. 2001); Comark, 156 F.3d at 1187; Tandon Corp. v. U.S. Int'l Trade Comm'n, 831 F.2d 1017, 1023 (Fed.Cir.1987). That presumption is especially strong when the limitation in dispute is the only meaningful difference between an independent and dependent claim, and one party is urging that the limitation in the dependent claim should be read into the independent claim. SunRace Roots Enter. Co. v. SRAM Corp., 336 F.3d 1298, 1303 (Fed. Cir.2003); see also Ecolab Inc. v. Paraclipse, Inc., 285 F.3d 1362, 1375-76 (Fed. Cir.2002); Wengner Mfg., 239 F.3d at 1233 (Claim differentiation . . . is clearly applicable when there is a dispute over whether a limitation found in a dependent claim should be read into an independent claim, and that limitation is the only meaningful difference between the two claims.). If we were to give curved in Claim 1 the meaning which Stryker advances, Claim 1 would cover only nails that substantially pass [] within [their] own envelope[s]. Such a restrictive reading would render Claims 1 and 13 identical in scope. Since independent claims are presumed to have broader scope than their dependents, the presumption is that Claim 1 should not be limited in the manner Stryker urges. For the reasons discussed above, that presumption has not been rebutted. 24 Stryker also argues that the district court's exclusion of sharp corners or sharp angles renders the construction insufficiently definite, since the court did not specify precisely how sharp is too sharp. However, a sound claim construction need not always purge every shred of ambiguity. The resolution of some line-drawing problems—especially easy ones like this one—is properly left to the trier of fact. See PPG Indus. v. Guardian Indus. Corp., 156 F.3d 1351, 1355 (Fed.Cir.1998) ([A]fter the court has defined the claim with whatever specificity and precision is warranted by the language of the claim and the evidence bearing on the proper construction, the task of determining whether the construed claim reads on the accused product is for the finder of fact.); Modine Mfg. Co. v. U.S. Int'l Trade Comm'n, 75 F.3d 1545, 1554 (Fed.Cir.1996) (whether claim limitation requiring diameter of about 0.040 inch embodied held a matter of technologic fact); see also Abbott Labs. v. Baxter Pharm. Prods., Inc., 471 F.3d 1363, 1368 (Fed.Cir.2006) (where result is the same under any reasonable construction, we need not construe [the disputed] phrase with numerical exactitude.). Here, the accused product has a rounded-off six-degree angle in its shaft. A reasonable jury could have found that in the context of this sort of nail, a rounded bend of six degrees was not a sharp angle. The jury's conclusion is bolstered by the testimony of Stryker's own technical expert, who noted in reference to the Stryker nail that there's no sharp angle there. There may be some area of imprecision within the district court's without sharp angles construction, but this accused product is in no danger of falling within that area. The construction is correct, and the jury's finding that the Stryker nail possesses a curved shank is supported by substantial evidence. 25