Ellipse Corporation v. Ford Motor Company

• Decision Date: 13 December 1971
• Docket Number: 18428.,No. 18427,18427
• Citation: 452 F.2d 163
• Parties: ELLIPSE CORPORATION, Plaintiff-Appellee, Cross-Appellant, v. FORD MOTOR COMPANY, Defendant-Appellant, Cross-Appellee.
• Court: U.S. Court of Appeals — Seventh Circuit

452 F.2d 163 (1971)

ELLIPSE CORPORATION, Plaintiff-Appellee, Cross-Appellant, v. FORD MOTOR COMPANY, Defendant-Appellant, Cross-Appellee.

Nos. 18427, 18428.

United States Court of Appeals, Seventh Circuit.

September 29, 1971.

Rehearing Denied December 13, 1971.

COPYRIGHT MATERIAL OMITTED

Norman Lettvin, Chicago, Ill., for Ellipse Corp.; George H. Gerstman, Chicago, Ill., of counsel.

Carlton Hill, Chicago, Ill., amicus curiae.

J. Arthur Gross, James Van Santen, Hill, Sherman, Meroni, Gross & Simpson, Chicago, Ill., Lloyd M. Forster, Farley, Forster & Farley, Detroit, Mich., for TRW Inc.; Eugene E. Ford, Joseph T. Gorman, Kenneth G. Preston, Jr., Law Department, TRW Inc., Cleveland, Ohio, of counsel.

George N. Hibben, Chicago, Ill., Arlie O. Boswell, Jr., Hibben, Noyes & Bicknell, Chicago, Ill., for Ford Motor Co.; Donald J. Harrington, Office of the General Counsel, Ford Motor Co., Dearborn, Mich., of counsel.

Before HASTINGS, Senior Circuit Judge, and KILEY and KERNER, Circuit Judges.

KILEY, Circuit Judge.

Ford Motor Company (Ford) has appealed from a district court judgment¹ that claims 3 and 1 of Ellipse Corporation's (Ellipse) Rhine patent² No. 2,628,568 were valid and had been infringed by Ford's accused power steering pumps. We affirm in part and reverse in part.

Ellipse is an Illinois corporation formed in 1945 to develop and promote the pumps of Marvin Rhine, who subsequently filed application for the patent in suit here. Two years after incorporation Ellipse terminated regular operations. However, it continued to prosecute the Rhine patent application and to solicit the interest of other companies in its pumps.

The patent application was granted in February, 1953, and in 1956 Ford purchased two pumps from Ellipse. In 1962 Ellipse, in a letter, charged Ford with infringement. Ford declined an offer of license and denied any infringement. The accused devices are the balanced power steering slipper pumps which Ford began using in all of its 1965 automobiles except the Lincoln. On August 2, 1966, Ellipse filed its original complaint charging Ford with infringement of two "forms"³ of its slipper pumps. Ellipse's subsequent amended complaint charged infringement only against one "form" of pump, the power steering pump. Ford defended on customary grounds of invalidity and non-infringement.

The Rhine patent discloses a rotary pump consisting of a series of stacked circular rotor units driven by a shaft. This assembly is enclosed by a casing referred to as the stator. Each rotor has a series of rounded pockets carved around its periphery. In each pocket is a slipper or blade of similar shape to the pocket. The slipper is permitted to move freely within the pocket. Figure (2) of the patent application shows that the stator departs from the rotor on opposite sides, forming a crescent shaped chamber in each space created. Each chamber has an inlet and an outlet passage through the stator wall, and 90° apart from each other.

As the rotor turns, centrifugal force joins with fluid pressure behind the slippers to push the slippers radially outward against the inner stator wall. When the slippers move through the crescent shaped chambers, they tend to move somewhat in and out of the pockets, since they always remain firmly pressed against the stator wall. This in-and-out movement draws fluid in through the inlet passage and forces it out through the outlet passage of each chamber.

I. SCOPE OF THE INVENTION

The central issue concerns the meaning and scope of claim 3⁴ of the patent which calls for, inter alia, A) an "out-of-round stator cavity," and B) "area contact" between the outer surface of the slippers and the inner wall of the stator for all positions of rotation.

Ellipse contends that the language of the patent discloses only a "balanced" slipper pump with a "mismatching area contact" beween the slippers and the stator. In a "balanced" pump the stator departs from the rotor at opposite ends to provide two diametrically opposed crescent shaped pumping chambers, each with its own inlet and outlet. This is in contrast to an "unbalanced" pump where the stator and the rotor are eccentrically positioned so that there is only one pumping chamber. "Mismatching area contact" between two arcuate surfaces is to be distinguished from and lies somewhere between a line contact — as in a roller pump — and a perfect surface-to-surface contact, where the curvature of the outer surface of the slipper is the same as the curvature of the inner surface of the stator.

This purported "mismatching contact" is the inventive feature of the pump and distinguishes it from the prior art. The mismatching creates a very thin film of oil between the slippers and the stator wall for all positions of rotation; it reduces the friction between the sliding surfaces, adds to the working life of the pump and also increases the pump's efficiency.

Ford asserts error in the district court findings that 1) "area contact" meant "mismatching area contact," and 2) that "out-of round" was limited to an "elliptical or equivalent" stator cavity. Specifically Ford contends that the language of claim 3 calls for total surface-to-surface contact (i. e., no mismatch) because "area contact" denoted only total surface contact in the prior art. Ford also argues that by amending the claim to call for an "out-of-round" stator cavity, Rhine abandoned his original limitation that the stator cavity be elliptical in shape. Since only an elliptically shaped stator would compel a "mismatching contact" between the slippers and the stator for all positions of rotation, Ford contends that file wrapper estoppel applies and precludes Ellipse from asserting that the patent application disclosed only a "mismatching area contact."

The general rules for determining the scope and meaning of patent claims are well settled. Claims are to be construed in the light of the specifications and both are to be read with a view to ascertaining the invention. United States v. Adams, 383 U.S. 39, 49, 86 S.Ct. 708, 15 L.Ed.2d 572 (1965). Proceedings before the Patent Office should be considered in determining the scope of the claims. Graham v. John Deere Co., 383 U.S. 1, 33, 86 S.Ct. 684, 15 L.Ed.2d 545 (1970). A patentee can choose his own terms and use them as he wishes so long as he remains consistent in their use and makes their meaning reasonably clear. Universal Oil Products Co. v. Globe Oil and Refining Co., 137 F.2d 3, 6 (7th Cir. 1943), affirmed 322 U.S. 471, 64 S.Ct. 1110, 88 L.Ed. 1399 (1944); Dennis v. Pitner, 106 F.2d 142, 148 (7th Cir. 1939).

A.

Applying these principles, we agree with Ellipse that there is nothing in the specifications which would indicate that anything but a balanced pump was disclosed. Figure (2) of the specifications clearly shows a balanced pump. The specifications state that one object of the pump is to "effect intake of fluid at opposite points" thus indicating the presence of two opposite pumping chambers which results in a balanced pump.

The term "out-of-round" used to describe the Rhine pump stator wall does not appear in the specifications. "Elliptical" is the only term used there to define the shape of the stator, and it is employed there three times. An examination of the file wrapper shows that all of the original patent claims except original claim 3 used the term "elliptical" to describe the stator. The term "out-of-round" was later substituted for "elliptical" but we do not think — as Ford argues — that the patentee thereby abandoned the limitation of an "elliptical or equivalent" stator cavity.

The doctrine of file wrapper estoppel is that an applicant who acquiesces in rejection of his patent claim and accordingly modifies it to secure its allowance, will not subsequently be allowed to expand (or narrow) his claim by interpretation to include limitations originally given up, or their equivalents. Schriber-Schroth Co. v. Cleveland Trust Co., 311 U.S. 211, 220-221, 312 U.S. 654, 61 S.Ct. 235, 85 L.Ed. 132 (1940); Ekco Products Co. v. Chicago Metallic Manufacturing Co., 347 F.2d 453, 454-55 (7th Cir. 1965). A necessary condition for the establishment of a file wrapper estoppel is that the patentee must have narrowed (or broadened) his claim in response to an objection by the Patent Office in order to obtain the patent. Bishman Manufacturing Co. v. Stewart-Warner Corp., 380 F.2d 336, 340 (7th Cir. 1967), cert. denied 389 U.S. 897, 88 S.Ct. 216, 19 L.Ed.2d 214 (1967). The application of the doctrine is limited to changes made to overcome rejections by the Patent Office because the claim was anticipated by the prior art, Eimco Corp. v. Peterson Filters and Engineering Co., 406 F.2d 431, 438 (10th Cir. 1968), cert. denied 395 U.S. 963, 89 S.Ct. 2105, 23 L.Ed.2d 749. It will not apply where changes in the claim are directed to merely overcoming difficulties in particular wording or indefiniteness, Eimco, supra; Sears, Roebuck & Co. v. Jones, 308 F.2d 705, 708-709 (10th Cir. 1962), cert. denied 371 U.S. 952, 83 S.Ct. 509, 9 L.Ed.2d 501 (1963), or adhering to the most descriptive recitation of his (patentee's) structure. Bishman, 380 F.2d at 340.

There is nothing in the file wrapper to estop Ellipse from limiting claim 3 to an "elliptical or equivalent" stator cavity. Claim 3 was originally rejected because of the location of the inlet and outlet passages. The Patent Office made no direct reference to the elliptical shape of the stator, and the substitution by Rhine of "out-of-round" for "elliptical" was not directed to overcoming any prior art limitations on the shape of the stator cavity. Rhine's correspondence with the Patent Office shows that the change in the wording of claim 3 was for the purpose of making it clear that he was not purporting to be the inventor of an elliptical stator cavity. There is no file wrapper estoppel where the change in the wording was to clarify that the stator cavity of the Rhine pump could...