## Facts

- Frank Young conceived an expandable envelope and reduced it to practice by November 1965.
- Young did not file a patent application until February 7, 1968.
- During the delay, Young sought manufacturing capability, including attending a paper-converting machinery convention in Germany, checking whether his company had a suitable machine, locating a machine that could manufacture the envelope, and conducting a successful test run.
- Howard Dworkin independently conceived and reduced to practice a similar expandable envelope between January 31, 1967, and October 6, 1967.
- Dworkin filed a patent application on December 28, 1967, more than a month before Young filed.
- The Patent Office declared an interference to determine priority of invention.

## Issues

1. Whether Young’s more-than-two-year delay between reduction to practice and patent filing constituted “suppression or concealment” under 35 U.S.C. § 102(g), causing Young to lose priority to Dworkin.

## Decision

- The court affirmed the Board of Patent Interferences’ award of priority to Dworkin.
- The court held that the evidence supported a finding that Young suppressed or concealed the invention within the meaning of § 102(g).
- The court accepted that a lengthy delay, inadequately justified by the inventor’s activities, can support an inference of suppression or concealment.
- The court upheld the Board’s factual determination as supported by substantial evidence.

## Legal Principles

- Under pre-AIA 35 U.S.C. § 102(g), the first party to reduce to practice generally has priority unless that party abandons, suppresses, or conceals the invention.
- Suppression or concealment may be inferred from a prolonged, insufficiently explained delay between reduction to practice and patent filing or other public disclosure; proof does not require express secrecy or an intent to hide the invention.
- When a senior party defeats an earlier reduction to practice by alleging suppression or concealment, the senior party bears the burden to prove suppression or concealment by a preponderance of the evidence.
- Efforts directed primarily to commercial readiness or manufacturing arrangements do not necessarily excuse a long delay unless they reflect reasonably continuous diligence toward timely public disclosure or filing.
- A later inventor who independently invents and files first may obtain priority if the earlier reducer to practice is found to have suppressed or concealed the invention.

## Conclusion

The court sustained the priority award to Dworkin because Young’s extended delay in filing after reduction to practice, despite some intervening activity, supported an inference of suppression or concealment under § 102(g), allowing the later inventor who filed first to prevail in the interference.


Young v. Dworkin, 489 F.2d 1277 (C.C.P.A. 1974)