MARKEY, Chief Judge.
D.M.I., Inc. (DMI) appeals from a grant of summary judgment of noninfringement by the United States District Court for the
DMI sued Deere & Company (Deere) for infringement of U.S. Patent 3,817,333 ('333 patent). The patent discloses and claims a plow system with means for adjusting the spacing of plow units while the plow is moving. Claims 1 and 8 are the only independent claims of the '333 patent.
Claim 1 contains this limitation:
Claim 8 contains this limitation:
The specification of the '333 patent contains these references to "compensating means":
Deere moved for an order that its accused plow "does not infringe claims 1-9" of the '333 patent.
The district court granted Deere's motion, saying:
Whether the district court erred in granting summary judgment of non-infringement.
As the district court recognized, "[s]ummary judgment is as appropriate in a patent case as in any other" when it is shown that no genuine issue of material fact remains for decision and that the movant is entitled to judgment as a matter of law. Barmag Barmer Maschinenfabrik A.G. v. Murata Mach., Ltd., 731 F.2d 831, 835, 221 USPQ 561, 564 (Fed.Cir.1984); Union Carbide Corp. v. American Can Co., 724 F.2d 1567, 220 USPQ 584 (Fed.Cir.1984). It is at least conceivable that comparison of a properly interpreted claim with a stipulated or uncontested description of an accused device or process would reflect such an absence of material fact issue as to warrant summary judgment of infringement or noninfringement. Because infringement is itself a fact issue, however, a motion for summary judgment of infringement or noninfringement should be approached with a care proportioned to the likelihood of its being inappropriate.
In the present case, the district court erred: (1) as a matter of law in interpreting the claims; and (2) failing to note the presence of material fact issues.
(1) Claim Interpretation
The district court said claim 1, "as thus interpreted," was not infringed by the accused Deere structure. As this court stated in Raytheon Co. v. Roper Corp., 724 F.2d 951, 956, 220 USPQ 592, 596 (Fed.Cir.1983), "Claim interpretation is a legal matter subject to review free of the clearly erroneous standard applicable to fact findings."
The interpretation adopted here by the district court is in law twice flawed. It was adopted in contravention of the statute, 35 U.S.C. § 112, and it involved a reading into independent claim 1 of a limitation appearing in dependent claim 4.
Paragraph 6 of 35 U.S.C. § 112 reads:
The first flaw occurred here when the district court apparently lost sight of the function appearing in the involved claims. That function is clearly expressed in the language "for maintaining said steering wheel ... lateral settings of said plow units" (claim 1) and "for correcting the disposition ... for all lateral adjustments of said units" (claim 8). Its attention having been focused on a felt, but non-existent, need to find a "definition" of "compensating means" per se in the claim and on an unfounded fear that a "result" rather than a function might be covered,
The second legal flaw in the district court's interpretation of the claim in this case stemmed from an apparent non-awareness of the presence of this limitation in dependent claim 4:
The district court said "as a general rule a limitation cannot be read into a claim to avoid infringement," citing Kalman v. Kimberly-Clark Corp., 713 F.2d 760, 218 USPQ 781 (Fed.Cir.1983), cert. denied, 465 U.S. 1026, 104 S.Ct. 1284, 79 L.Ed.2d 687 (1984). Where, as here, the limitation sought to be "read into" a claim already appears in another claim, the rule is far more than "general." It is fixed. It is long and well established. It enjoys an immutable and universally applicable status comparatively rare among rules of law. Without it, the entire statutory and regulatory structure governing the drafting, submission, examination, allowance, and enforceability of claims would crumble. This court has confirmed the continuing life of the rule. Amstar Corp. v. Envirotech Corp., 730 F.2d 1476, 221 USPQ 649 (Fed.Cir.1984); Raytheon Co. v. Roper Corp., supra; Fromson v. Advance Offset Plate, Inc., 720 F.2d 1565, 219 USPQ 1137 (Fed.Cir.1983). Indeed, in Kalman, 713 F.2d at 770, this court quoted with approval this clear statement of the rule found in Deere & Co. v. Int'l Harvester Co., 658 F.2d 1137, 1141, 211 USPQ 11, 16 (7th Cir.), cert. denied, 454 U.S. 969, 102 S.Ct. 514, 70 L.Ed.2d 386 (1981):
The district court's reliance on Hale Fire Pump Co. v. Tokai, Ltd., 614 F.2d 1278, 67 CCPA 121, 205 USPQ 123 (1980), was misplaced. In that case, the prosecution history established that the claim was allowed because the disclosed jackscrew embodiment of "releaseable means" had a mechanical advantage in disassembling a pump, an advantage absent in a two-part pump. Nothing of record here indicates that claims 1 and 8 were allowed because the disclosed embodiment of the claimed compensation means was a parallelogram. On the contrary, the specification was here amended solely to provide an antecedent basis for the "means for compensating" limitation in the claims.
(2) Fact Issues
Whether Deere's hydraulically operated plow system includes a compensating means that is an equivalent of DMI's parallelogram and that performs the function of that means as set forth in claims 1 and 8 is a question of fact. In terms of the statute, § 112, an affirmative answer to that question would mean that Deere's hydraulic means would be an "equivalent" of DMI's parallelogram or some part thereof. If (as appears uncontested) Deere's plow system includes all the other limitations of those claims, it would also mean that they are literally infringed, for in that event the entirety of claims 1 and 8 would "read" directly on Deere's plow system.
Thus the word "equivalent" in § 112 should not be confused, as it apparently was here, with the "doctrine of equivalents." In applying the doctrine of equivalents, the fact finder must determine the range of equivalents to which the claimed invention is entitled, in light of the prosecution history, the pioneer-non-pioneer status of the invention, and the prior art. It must then be determined whether the entirety of the accused device or process is so "substantially the same thing, used in substantially the same way, to achieve substantially the same result" as to fall within that range. Graver Tank & Mfg. Co. v. Linde Air Products Co., 339 U.S. 605, 610, 70 S.Ct. 854, 857, 94 L.Ed. 1097, 85 USPQ 328, 330 (1950). In applying the "means plus function" paragraph of § 112, however, the sole question is whether the single means in the accused device which performs the function stated in the claim is the same as or an equivalent of the corresponding structure described in the patentee's specification as performing that function.
DMI at one point indicates that it intends to rely on the doctrine of equivalents to support its assertion that claims other than claims 1 and 8 are infringed. Whether such other claims are infringed under the doctrine of equivalents is also a question of fact.
DMI's reliance on the doctrine of equivalents in respect of other claims may account for the district court's concern that DMI was "claiming an impermissible extension of equivalence to include any mechanism which is capable of steering the rear wheel," and was trying to avoid "its own patentee's definition of a `compensating means' and claim equivalence in every structure which achieves the same result." That concern, as the district court noted, was fostered by Deere's arguments. It is unfounded.
Accordingly, the entry of summary judgment is reversed and the case is remanded for further proceedings.
REVERSED and REMANDED.