## Facts

- Thaddeus Leese obtained a U.S. patent for a fluid-regulating valve and represented himself as the inventor.
- Leese agreed in writing to sell and assign Bernard Gloekler Company his “entire interest” in the invention and patent for $5,000.
- The agreement was evidenced by a written offer and a receipt acknowledging a $100 part payment.
- The writings contained no express warranty that the patent was valid, novel, or non-infringing.
- After paying $100, Gloekler investigated and concluded earlier patents covered the same subject matter, making Leese’s patent commercially worthless for exclusive use.
- Gloekler refused to pay the remaining $4,900, and Leese sued for the contract price.

## Issues

1. Whether a sale/assignment of patent rights implies a warranty of patent validity or non-infringement when the contract contains no express warranty.
2. Whether the buyer may withhold the remaining purchase price solely because the patent is invalid or anticipated, absent proof of fraud.

## Decision

- The Supreme Court of Pennsylvania affirmed judgment for Leese.
- The court held no implied warranty of validity or non-infringement arises from a patent assignment without an express warranty.
- Because fraud was not shown, Gloekler remained obligated to pay the balance of the agreed purchase price.
- The court treated the written offer and receipt as the complete agreement and rejected reliance on alleged oral assurances inconsistent with the writings.

## Legal Principles

- In a patent sale or assignment, the law does not imply a warranty that the patent is valid, novel, or non-infringing; such protection must be expressly contracted for.
- A buyer who purchases a patent right without an express warranty assumes the risk that the patent may be invalid or anticipated, unless the buyer proves fraud or actionable misrepresentation.
- When parties reduce their agreement to writing, alleged prior or contemporaneous oral statements generally cannot add to or vary the written terms absent an exception such as fraud.

## Conclusion

The court enforced the patent-purchase agreement as written, placing the risk of patent invalidity on the buyer where the contract contained no express warranty and the buyer failed to prove fraud, and therefore required payment of the remaining purchase price.


Leese v. Bernard Gloekler Co., 287 Pa. 295, 135 A. 206 (Pa. 1926)