275

Opinion of the Court

was described in the last paragraph of the original specification "must also be illustrated or else all reference to the same must be eliminated from the disclosure."

The plaintiff responded to the first Patent Office action by cancelling all six of the original claims and substituting claims 7 and 8. Again, neither of these two claims was drawn specifically to modification II. The examiner in the second Patent Office action stated that the new claims were allowable and repeated his requirement either for illustration or cancellation of modification II. Plaintiff did not supply the additional drawings but instead asked that all mention of modification II be stricken from the specification. With this amendment, all of the examiner's objections were overcome and the patent was issued. Claims 7 and 8 of the application became claims 1 and 2 of the patent. They are as follows:

1. In an amphibious motor driven vehicle, a vehicle body, a driving clutch member mounted in said body, a propeller shaft, a propeller carried by said shaft, a casing rotatably receiving said shaft, a driven clutch member carried by said shaft, and means mounting said casing to swing about a horizontal axis on said body whereby the driven clutch member may be swung into engagement with the driving clutch member with the propeller occupying an operative position and out of engagement with the driving clutch member with the propeller assuming an elevated inoperative position.

2. An amphibious vehicle as claimed in claim 1 wherein said propeller shaft is composed of two sections coupled by a universal joint, the casing including front and rear sections, the front casing section being connected with the mounting means and the rear section being movable about a vertical axis passing through said universal joint.

Sometime after October 11, 1953, within 6 years of the date of filing of the complaint in this case, the defendant manufactured several amphibious vehicles which embodied a propulsion device similar to the one disclosed by the plaintiff in his patent. The plaintiff claims that the defendant's device is equivalent in all respects to his patented device and that the defendant has infringed his patent. The defendant contends that its device is identical to modification II, which

Opinion of the Court

154 Ct. Cl.

the plaintiff originally described in his patent application, but since the plaintiff struck all mention of this modification from his application in response to rejections by the Patent Office, he is now estopped from asserting that the defendant's device lies within the scope of the patent claims.

Whether the claims of the patent read directly on the defendant's propulsion device, or whether this device is the equivalent of the plaintiff's patented device are questions of fact, Graver Tank & Mfg. Co., Inc. v. Linde Air Products Co., 339 U.S. 605 (1950), and will not be decided on this motion. The issue for determination now is whether the plaintiff is estopped from claiming that the defendant's device, an admitted modification of the plaintiff's patented device, lies within the scope of the claims of the patent because the plaintiff failed to illustrate this modification in his patent application, because he struck all mention of this modification from his application, and because he accepted the patent with this deletion.

Estoppel in patent law is simply an application of familiar equitable principles to the technique of Patent Office prosecution and patent infringement litigation. A person in an infringement suit may not take a position inconsistent with the one he maintained before the Patent Office in the proceedings which led to the issuance of his patent. The defendant in a thorough brief emphasizes the frequently recited rules that where an applicant for a patent, in response to rejections by the Patent Office, amends his application by cancelling entire claims or objectionable features of claims, or by introducing new elements of limitation into the claims, the claims as allowed must be interpreted with reference to those claims which have been cancelled or rejected. Exhibit Supply Co. v. Ace Patents Corp., 315 U.S. 126 (1942); Martin v. United States, 86 Ct. Cl. 311 at 379 (1938). Allowed claims may not be construed to have the same meaning which they would have had without amendment. Schriber-Schroth Co. v. Cleveland Trust Co., 311 U.S. 211 (1940). A patentee may not resort to the doctrine of equivalents to recapture claims which he has surrendered by amendment, Smith v. Magic City Kennel Club, Inc., 282 U.S. 784 (1931), and he is estopped by the file wrapper to

275

Opinion of the Court

contend for such construction of the claims as would have the effect of disregarding the amendment. Keystone Driller Co. v. Northwest Engineering Corp., 294 U.S. 42 (1935); Binckley v. United States, 83 Ct. Cl. 444 at 471 (1936). See generally, 69 C.J.S. Patents § 212 (1951). While we do not dispute the value of these rules in guiding the proper construction of amended claims, we do not believe they apply in the instant case.

The claims which the plaintiff submitted with his patent application did not mention the specific arrangement of elements of modification II. Six claims were filed originally. Three claims covered the basic combination and three claims included an additional element (a universal joint) in the propeller shaft. Following a rejection by the patent examiner, these claims were cancelled and two new claims were submitted. One claim again covered the basic combination and one claim included additionally the universal joint in the propeller shaft between the clutch and the propeller. No claim was ever filed, and of course no claim was ever cancelled, which was drawn specifically to the combination we have designated as modification II. The only reference. to modification II was in the original specification.2

The defendant would have us treat the cancellation of part of the specification as equivalent to the cancellation of a claim, and would extend the rules stated above to the situation before us now. It does not appear to us, however, that the conditions which require careful vigil over the development of the claims apply equally to the specification. The scope of the patent monopoly must be ascertainable with a high degree of certainty or the patent will frustrate rather than promote the progress of science and the useful arts. The claims become of utmost importance, for they are of the nature of metes and bounds and describe for the world the area of the invention beyond which no one may go without trespassing. Altoona Publix Theatres, Inc., v. America TriErgon Corp., 294 U.S. 477 (1935); Ethyl Gasoline Corp. v. United States, 309 U.S. 436 (1940); Marconi Wireless Telegraph Co. of America v. United States, 99 Ct. Cl. 1, affirmed,

We use the word "specification" throughout this opinion to indicate the descriptive material in the patent application but not the claims.

Opinion of the Court

154 Ct. Cl.

320 U.S. 1 (1943); Stuart Oxygen Co., Ltd., v. Josephian, 162 F.2d 857 (9th Cir. 1947). People naturally rely on the wording of the claims. They are also entitled to rely on language deliberately excluded from the claims because this tends to indicate what the inventor has agreed his invention is not.

The specification serves a purpose different from the claims; it does not necessarily measure the invention. Continental Paper Bag Co. v. Eastern Paper Bag Co., 210 U.S. 405 at 419 (1908); Kuhne Identification Systems v. United States, 82 Ct. Cl. 237 at 258 (1936). It must only disclose an operative embodiment of the invention in such a manner that one having ordinary skill in the art will be taught how to utilize the invention. 35 U.S.C. § 112. When the nature of the case admits, an applicant for a patent shall furnish drawings. 35 U.S.C. § 113. However, the Patent Act does not require the specification to contain an illustrated description of every possible infringing device in order that a patentee be protected against future infringement. Thurber Corp. v. Fairchild Motor Corp., 269 F. 2d 841 (5th Cir. 1959).

Of course, a patentee in an infringement suit may not claim as his invention that which he has specifically disclaimed in the patent specification regardless of the scope of the allowed claims. Manton-Gaulin Mfg. Co. v. WrightZeigler Co., 271 F. 391 (1st Cir. 1921). Furthermore, a patentee is bound by even self-imposed limitations which he notes in the specification. Bergman v. Aluminum Lock Shingle Corp. of America, 251 F. 2d 801 (9th Cir. 1957). But we do not believe that cancelling a part of the specification referring to an optional arrangement of elements in a patentable combination, is an alternative to filing additional drawings, has the effect of a disclaimer or a limitation of the claims.

In this case nothing was amended, cancelled, or withdrawn to avoid an art rejection directed specifically to modification II. We think it cannot fairly be said that the plaintiff is trying to recapture claims which he has surrendered by amendment. There is nothing on which an estoppel can be based. Any other decision would carry the doctrine of file

275

Syllabus

wrapper estoppel beyond the limits set out in the previous cases and beyond what we believe fairness to the parties requires. The prosecution of an application before the Patent Office is a complicated proceeding where the penalties for misstatements and omissions must frequently be stringent. We do not believe it would further the objectives of the Patent Act or serve any other useful purpose to bar the plaintiff in this suit by attaching overriding significance to the cancellation of material from the specification, an act heretofore commonplace in patent prosecution.

The claims of the patent are entitled to be read in the light of the specification as it is without specifically excluding from their scope an arrangement of elements as in modification II.

We do not now determine whether the claims of the patent read directly on the defendant's propulsion device, or whether this device is the equivalent of the plaintiff's patented device. These still remain questions of fact on which the parties are entitled to make their proofs.

The defendant's motion for summary judgment will be denied.

It is so ordered.

DURFEE, Judge; LARAMORE, Judge; MADDEN, Judge; and WHITAKER, Judge, concur.

CHARLOTTE CHEMICAL LABORATORIES, INC., ET AL. v. THE UNITED STATES

[No. 316-55. Decided June 7, 1961]

ON THE PROOFS

Patents; validity; prior patents-no new results. In an action by plaintiff to recover compensation for the unauthorized manufacture for and use by the Government of a machine for the washing of laboratory glassware allegedly covered by claims contained in two patents issued to the plaintiff, it is held that the claims in suit were invalid over the disclosures of several prior patents because there was no new result or cooperation or conjoint action in the arrangement of features as set forth in the claims of plaintiff's patent. Petition dismissed.