## Facts

- Applicants filed a U.S. patent application on July 25, 1958, for sulfonyl urea compounds, claiming foreign priority to a German filing on July 31, 1957.
- The examiner rejected certain claims as obvious under 35 U.S.C. § 103, relying primarily on a U.S. patent to Habicht and secondarily on a U.S. patent to Wagner.
- Habicht’s U.S. patent was filed in the United States on January 23, 1958, and claimed foreign priority to a Swiss filing on January 24, 1957 under 35 U.S.C. § 119.
- The rejection followed an interference between the applicants and Habicht in which the applicants conceded priority on the count to Habicht based on Habicht’s earlier Swiss filing date.
- The Patent Office Board of Appeals affirmed the § 103 rejection on the theory that Habicht’s U.S. patent was prior art as of its Swiss priority date, not its U.S. filing date.

## Issues

1. For purposes of 35 U.S.C. § 102(e) (and a corresponding § 103 obviousness analysis), whether a U.S. patent reference is effective as prior art as of its U.S. filing date or as of an earlier foreign priority date claimed under 35 U.S.C. § 119.

## Decision

- The court reversed the Board of Appeals and remanded.
- A U.S. patent used as prior art under § 102(e) is effective only as of the date its application was filed in the United States, not as of any earlier foreign priority date.
- Section 119 does not modify § 102(e)’s express limitation to applications “filed in the United States.”
- Because Habicht’s effective § 102(e) date was January 23, 1958 (its U.S. filing date), the Board erred by treating Habicht as prior art as of January 24, 1957 (its Swiss filing date).

## Legal Principles

- Under 35 U.S.C. § 102(e), a U.S. patent reference is prior art as of the date the underlying application was filed in the United States.
- The foreign priority benefit of 35 U.S.C. § 119 affects priority for the patentee’s own rights but does not change the § 102(e) prior-art date of a U.S. patent used against others.
- The statutory phrase “filed in the United States” in § 102(e) forecloses using a foreign priority date to backdate a U.S. patent reference for prior-art purposes.

## Conclusion

The court held that foreign priority under § 119 cannot be used to give a U.S. patent earlier prior-art effect under § 102(e); the reference date remains the U.S. filing date, requiring reversal of the Board’s obviousness affirmance premised on backdating to a foreign filing.


In re Hilmer (Hilmer I), 359 F.2d 859 (C.C.P.A. 1966)