## Facts

- Joseph Shaw obtained a U.S. patent in June 1822 for an improvement in guns and firearms involving a priming-head and case for percussion firing.
- Claiming the 1822 patent specification was defective, Shaw surrendered that patent and received a new patent dated May 7, 1829, covering the same improvement.
- The 1829 patent stated a 14-year term but tied the exclusive right to the original patent date (June 19, 1822), effectively limiting it to the unexpired remainder of the original term.
- Shaw sued Joseph Cooper in the U.S. Circuit Court for the Southern District of New York for infringing the patent beginning August 1, 1829.
- Cooper defended on grounds including: (i) Shaw was not the original inventor; (ii) the improvement or material parts were known and used in the United States and abroad before Shaw’s invention and before his patent application; (iii) the invention originated with a person in England; and (iv) the specification failed to distinguish what was new from what was already known.
- The jury returned a verdict for Cooper; Shaw sought Supreme Court review by writ of error.

## Issues

1. Whether a patent granted after surrender of an earlier patent for defective specification is treated as a continuation relating back to the original patent, rather than as a new grant on an original application.
2. If it relates back, whether the patentee’s rights are governed by the patent law in force at the time of the original application (1822) or at the time of the reissued patent (1829).
3. Whether prior public knowledge or use of the invention (domestically or abroad) before the application renders the patent void, and whether that rule applies similarly to citizens and aliens under the governing statutes.
4. What constitutes “known or used” for invalidating a patent, including the effect of unauthorized public disclosure and the inventor’s acquiescence.

## Decision

- The Supreme Court affirmed the judgment for Cooper.
- The Court held that Shaw’s 1829 patent, issued upon surrender of the 1822 patent, related back to the original patent’s issuance and was not treated as a new, original grant.
- Because the second patent was a continuation of the first, Shaw’s rights were governed by the law applicable to the 1822 application.
- The Court held that if an invention was known or used by the public before the patent, the patent is void; this principle applies substantially the same to citizens and aliens.
- The Court recognized that public knowledge or use surreptitiously obtained and disclosed without the inventor’s consent does not automatically defeat the patent; acquiescence by the inventor may support an inference of abandonment to the public.

## Legal Principles

- A patent issued after surrender of a prior patent for defective specification is a continuation that relates back to the original patent’s issuance; it does not restart the patent term.
- When a reissued patent relates back, the patentee’s rights and validity conditions are determined under the patent law in force when the original application was made.
- A patent is void if, before the patentee’s application, the invention was known or used by the public; “known or used” refers to public knowledge or use, not the inventor’s own knowledge or experimentation.
- Under the governing early patent statutes, citizens and aliens are treated substantially alike regarding invalidation for prior public knowledge or use; foreign public knowledge or use can defeat an alien’s patent just as domestic public knowledge or use can defeat a citizen’s patent.
- Unauthorized public disclosure obtained without the inventor’s consent does not alone establish abandonment; continued acquiescence by the inventor may support a finding that the invention was dedicated to the public.

## Conclusion

The Court upheld a defense verdict in a patent infringement action, holding that a corrective patent granted after surrender for defective specification relates back to the original grant and is governed by the law applicable to the original application, and that prior public knowledge or use—subject to limits where disclosure was unauthorized and not acquiesced in—renders the patent invalid.


Shaw v. Cooper, 32 U.S. (7 Pet.) 292 (1833)