## Facts

- Ray-O-Vac owned, as assignee, Anthony Patent No. 2,198,413 (issued Apr. 23, 1940) covering a “leakproof dry cell for a flash light battery.”
- Conventional flashlight dry cells used a zinc cup as both electrode and container for a carbon electrode, electrolyte, and depolarizing mix.
- Over time or after short-circuiting, zinc erosion and formation of solids could expand contents, causing bulging, rupture, and leakage that damaged flashlight casings.
- The industry had long experienced leakage and swelling problems and commonly used warning notices rather than a structural solution.
- Anthony’s patent addressed these problems by adding an improved protective casing: a strong metal sheath to closely and rigidly confine the cell’s dimensions and to insulate the sheath from both terminals, reducing the risk of short-circuit and leakage damage.
- Ray-O-Vac marketed the Anthony cell and sued Goodyear and related parties for infringing claims 1–3.
- The district court held the patent valid and infringed; the court of appeals affirmed; the Supreme Court granted certiorari.

## Issues

1. Whether claims 1–3 of the Anthony patent were invalid for lack of invention in view of the prior art or for insufficient description.
2. Whether prosecution-history (file-wrapper) estoppel limited the claims so as to defeat Ray-O-Vac’s infringement theory.
3. Whether the Supreme Court should disturb concurrent lower-court findings on validity and infringement in a patent infringement suit.

## Decision

- The Supreme Court unanimously affirmed.
- Concurrent findings of the district court and court of appeals in a patent infringement suit would not be set aside unless clearly erroneous.
- Claims 1–3 of the Anthony patent were held valid and infringed.
- The defenses based on insufficiency of description and file-wrapper estoppel were rejected as unsupported by the evidence.

## Legal Principles

- When the district court and court of appeals concur on findings in a patent infringement suit, those findings are not set aside on further review unless clearly erroneous.
- A narrow combination patent in a developed technical field may be valid where the combination is found to produce a new and useful result addressing an unresolved practical problem.
- Challenges based on inadequate written description and prosecution-history estoppel are fact-dependent and may fail where the evidentiary record supports the lower courts’ rejection of those defenses.

## Conclusion

The Court upheld a narrow dry-cell battery patent and an infringement finding, emphasizing deference to concurrent lower-court determinations absent clear error and rejecting evidentiary challenges based on disclosure sufficiency and prosecution-history estoppel.


Goodyear Tire & Rubber Co. v. Ray-O-Vac Co., 321 U.S. 275 (1944)