## Facts

- Frederick C. Foster filed a U.S. patent application on August 21, 1956, claiming elastomeric synthetic polymers intended to combine properties associated with natural Hevea rubber with advantages of synthetic rubbers.
- The Patent Office rejected the claims as unpatentable in view of a printed publication dated August 1954 (“Binder”), relying on the publication’s disclosure to support an obviousness rejection.
- Foster submitted a pre-AIA Patent Office Rule 131 affidavit asserting an actual date of invention before December 26, 1952, i.e., before the Binder publication date.
- The examiner maintained the rejection; the Patent Office Board of Appeals affirmed.
- Foster appealed to the Court of Customs and Patent Appeals.

## Issues

1. Whether a patent applicant may use a Rule 131 affidavit to remove a printed publication as prior art when the publication is more than one year before the applicant’s U.S. filing date but post-dates the applicant’s asserted date of invention.
2. Whether a printed publication that is a statutory bar under 35 U.S.C. § 102(b) may be avoided by proof of earlier invention when the publication’s disclosure renders the claims obvious.

## Decision

- The court affirmed the Board of Appeals’ decision sustaining the rejection.
- A Rule 131 affidavit cannot be used to antedate a reference that qualifies as prior art under 35 U.S.C. § 102(b) because it was published more than one year before the U.S. filing date.
- Because the Binder publication was more than one year before filing and contained sufficient disclosure to make the claimed invention obvious, the claims were barred notwithstanding Foster’s asserted earlier invention date.

## Legal Principles

- 35 U.S.C. § 102(b) imposes an absolute statutory bar when an invention is described in a printed publication more than one year before the U.S. application filing date.
- The § 102(b) bar applies without regard to the applicant’s actual date of invention; earlier invention does not cure a delayed filing beyond the one-year period.
- Rule 131 practice is limited to antedating certain references (commonly § 102(a)-type prior art) and cannot defeat a § 102(b) printed-publication bar.
- If a § 102(b) publication provides enough disclosure to support an obviousness rejection of the claimed invention, the claims are unpatentable even if the applicant can show invention before the publication date.

## Conclusion

The court held that proof of earlier invention via Rule 131 cannot overcome the one-year printed-publication bar of § 102(b); because the Binder publication preceded Foster’s filing by more than one year and rendered the claims obvious, the patent claims remained unpatentable.


In re Foster, 343 F.2d 980 (C.C.P.A. 1965)