Exhibit Supply Co. v. Ace Patents Corp.

Citations: 315 U.S. 126; 62 S. Ct. 513; 86 L. Ed. 736; 1942 U.S. LEXIS 957Docket: Nos. 154, 155, 156

Court: Supreme Court of the United States; March 2, 1942; Federal Supreme Court; Federal Appellate Court

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Respondent initiated litigation through three separate lawsuits against petitioners for infringing on Nelson Patent No. 2,109,678, granted on March 1, 1938, related to a 'contact switch for ball rolling games.' The defenses raised included non-invention based on prior art, anticipation by prior publication, non-infringement, and file wrapper estoppel. The District Court and the Seventh Circuit Court of Appeals upheld the validity and infringement of Claim 4 of the patent. The Supreme Court granted certiorari to address the infringement decree, asserting it expanded the patent's scope through the doctrine of equivalents and that Nelson had surrendered Claim 4 during the amendment process at the Patent Office. 

The Court noted that the patent involves a resilient switch mounted on a game table that functions as a target, closing an electrical circuit when struck by a rolling ball. The design includes a conductor standard with a coil spring that deflects to contact a conductor ring, closing the circuit to operate a relay coil and connected game devices. The invention aims to encompass various modifications that do not stray from its core intent. Importantly, prior art did not reveal any device where the coil spring simultaneously functions as both a target and a switch, providing unique advantages for pinball games by allowing multiple targets to be activated by a single ball.

Claim 41 outlines the invention's components, which include a conductor standard anchored in a table, a coil spring suspended from the standard, and a conductor embedded in the table that interacts with the spring to complete an electrical circuit. The spring is designed to flex independently of the standard, allowing its movement to close the circuit when engaged with the conductor. The patent drawings illustrate the conductor as a ring or ferrule positioned perpendicular to the table, slightly elevated above its surface, with the coil spring's pendant leg centrally aligned to ensure contact upon impact.

Six accused devices differ from the claimed invention primarily in the configuration and support of the conductor means. In Exhibits 5 and 7, a nail or pin replaces the integrated ring conductor, creating contact above the table when the spring is struck. Exhibits 6 and 10 further modify the arrangement by using a metal plate on the table's surface to support the nail or pin, altering the relationship between the conductor and coil spring.

Exhibits 8 and 9 introduce an insulating core or sleeve around the coil standard, with a conductor wired in the circuit that connects when the coil flexes. In Exhibit 8, the sleeve is linked to a metal plate on the table, while in Exhibit 9, the conductor is positioned above the table. Overall, with the exception of Exhibits 5 and 7, the accused devices feature conductors not embedded in the table but supported by various insulating structures, affecting how the circuit is completed.

Petitioners argue that the respondent is estopped from claiming infringement based on the file wrapper record in the Patent Office. They contend that any estoppel can be bypassed, and infringement can only be established through the doctrine of equivalents, which they believe contradicts the statutory requirements for patent grants and the principle that patent claims define the invention. The relevant file wrapper history pertains to Claim 7, which was amended and ultimately allowed as Claim 4. 

The original Claim 7, along with its amendments, describes a ball rolling game apparatus featuring a table and a vertical standard with an electric circuit, including a coil spring that is designed to flex when struck by a ball. The original patent application contained six claims, all rejected for lacking patentable significance. Following amendments and the introduction of claims 7 and 8, the examiner reconsidered the patentability, allowing four claims but rejecting Claim 7 for not adequately defining the invention.

The examiner cited existing art where electrical contacts are made by flexing a coil spring and emphasized that the applicant needed to specify a unique contact structure in the claims. The applicant rejected the examiner's suggestion to define a specific contact structure and instead modified Claim 7 to clarify that the complementary conductor contact would be embedded in the table. 

Despite the applicant's argument that the claim should be allowed based on the unique configuration, the examiner acknowledged the applicant's point but noted the proposed design would be inoperative due to conflicting requirements. The applicant then revised the claim to specify its configuration more clearly, leading to its eventual allowance as Claim 4.

The original claim, prior to amendment, involved a nail or pin conductor engaged by a spring, as depicted in plaintiff's Exhibits 5 and 7. This claim was deemed operative since the conductor could be engaged when it projects above the table. The amended Claim 4 also pertains to the same exhibits, now stating that the nail or pin is "embedded in the table." Petitioners do not contest this embedding, acknowledging it in their brief. The term "embed" aligns with dictionary definitions and does not limit the conductor to residing entirely between the table's surfaces, as the specifications and drawings do not impose such a restriction. 

The patent drawings illustrate a ring conductor that slightly extends above and below the table. An examiner's rejection of Claim 7 suggested that an operable device could result from an embedded leg or nail, indicating the embedded element must be partially above the table to be engageable by the spring. Thus, "embedded" in Claim 4 encompasses any conductor fixed in the table, regardless of whether it protrudes. The amendment defining the conductor means as embedded did not exclude devices like Exhibits 5 and 7, which remain considered infringements.

Regarding the doctrine of equivalents, the respondent acknowledges that the conductor means in four other accused devices are not literally embedded in the table but argues they are mechanical equivalents to the claimed conductor. Petitioners challenge the necessity of the doctrine, asserting it undermines statutory requirements for patent descriptions. However, it is not necessary to resolve these issues, as the established principle states that claims cannot revert to a broader interpretation after a restrictive amendment.

The patentee originally proposed a broader claim, "carried by the table," but revised it to "embedded in the table" to address objections from the Patent Office related to prior art. This amendment significantly narrowed the claim, limiting it to combinations where the conductor means is both carried by and embedded in the table. As a result, the patentee effectively disclaimed any broader interpretation that included conductors merely carried by the table. This disclaimer is material and must be strictly construed against the patentee, meaning that the doctrine of equivalents cannot be used to reclaim the disclaimed scope. Consequently, it was determined that certain plaintiff's exhibits infringe on the modified claims, while others do not. 

In a dissenting opinion, Justice Black argued that the patent was void due to lack of invention or discovery, asserting that the patented combination did not introduce any new elements and merely applied an old device in a new context. He maintained that the Constitution and patent statutes only allow for patents that result from genuine innovations, and labeled the invention as a degradation of these standards.

Patentees possess legal rights, but the public also has rights that must be equally protected. In patent infringement cases, parties should not be allowed to prevent a court from addressing public interests by neglecting to challenge patentability. Judicial correction is warranted in cases of clear error. The excerpt also describes a specific patent claim involving a game with a horizontal table, detailing a vertical standard anchored to the table, an electric circuit, and a coil spring that interacts with a conductor embedded in the table. This design allows for the spring to close the circuit when flexed by a rolling ball. Relevant case law references are provided to support the arguments presented.