## Facts

- An inventor developed an improved folding infant high chair that collapsed into a compact package suitable for shipping and handling.
- The chair’s folding/attachment mechanism was known in prior patents; the asserted advance lay in combining that known feature with other structural elements in a high-chair configuration.
- Through an intermediary, the inventor provided a physical sample chair to the defendant manufacturer while proposing a royalty-based manufacturing arrangement.
- The defendant retained and examined the sample for about two months, then returned it and declined any agreement.
- The defendant later marketed a high chair very similar to the disclosed design without paying compensation.
- A patent later issued to the inventor (and a co-inventor) and was assigned to the plaintiff; the claims were drafted as a combination of structural elements.
- The plaintiff sued for (1) infringement after patent issuance and (2) quasi-contract/unjust enrichment for defendant’s use of the disclosed design before issuance and after negotiations contemplating payment.

## Issues

1. Whether the combination patent was valid over the prior art and, if valid, whether the defendant infringed (Count 1).
2. Whether the plaintiff could recover in quasi-contract for unjust enrichment for the defendant’s use of the disclosed design after royalty discussions, even if the patent was invalid or not infringed (Count 2).

## Decision

- The court held the patent invalid as an unpatentable aggregation/combination of known elements and entered judgment for the defendant on the infringement count.
- The court held the plaintiff could recover in quasi-contract for unjust enrichment based on the defendant’s appropriation and use of the disclosed design after receiving it in contemplated royalty negotiations.
- The court entered judgment for the plaintiff on the unjust-enrichment count and awarded monetary compensation measured by the value of the benefit wrongfully retained.

## Legal Principles

- A combination of old elements is not patentable where the combination does not produce a sufficiently new result beyond an aggregation or rearrangement of known parts.
- Patent invalidity defeats infringement liability but does not bar an independent restitution claim based on the parties’ dealings.
- A defendant may be liable in quasi-contract where an idea or design is disclosed in circumstances showing an expectation of compensation if used, and the defendant thereafter uses it without payment.
- Recovery in unjust enrichment does not require a valid patent or an express contract; it turns on whether retention of the benefit, obtained through the disclosure, would be unjust.

## Conclusion

The court rejected the patent-based claim because the asserted folding high-chair invention merely combined known elements, but it separately imposed restitutionary liability because the defendant used the disclosed design after receiving and evaluating it in negotiations that objectively contemplated paid use.


Trenton Indus. v. A. E. Peterson Mfg. Co., 165 F. Supp. 523 (S.D. Cal. 1958)