The assignee of a patent sued General Motors for infringement, and appeals from a judgment holding the patent invalid.

The patent-in-suit covers an automobile seat switch activated by pressure. The evidence was in conflict, but there was ample evidence to support the trial court’s finding that the GM (Szablowski) seat switch 1 anticipated the Safe Stop (Fontaine) seat switch. 2 Szablowski filed on September 16, 1971. Fontaine filed on November 17,1971.

Confronted with the prima facie difficulty presented by the adversary’s earlier filing, plaintiff attempted to prove by lay witnesses that the Fontaine patent had been reduced to practice before that of Sza-blowski. The trial court, however, found otherwise, and we cannot say that the finding is clearly erroneous.

The above finding of itself would invalidate the Fontaine patent and end the case. We note also the assertion that Fontaine’s pressure switch as described in his claim was different from all the prior art because it was recessed into the automobile seat. The allegedly infringing switch is also recessed. The trial judge was satisfied from the evidence that the idea of recessing the switch into the seat to avoid an unmarketable lump in the seat surface was about as obvious as dumping a rock out of a shoe. We agree.

Affirmed.