PER CURIAM:
The summary judgment of the district court that Coastal Dynamics design patent 208,474 on a miniature electric lamp is invalid is affirmed.
As a general rule, summary judgments in patent cases do not fare well, except experience does show they are sometimes appropriate in design patents which usually do not involve complicated factual situations. We find this case to be one where it was justified.
It is asserted by Coastal Dynamics that the trial court failed to find either way on its issue of “assignor estoppel.”
We are satisfied that by inference he did rule that the point was without merit and such a result is required by the dicta in Lear, Incorporated v. Adkins, 395 U.S. 653, 89 S.Ct. 1905, 23 L. Ed.2d 610, wherein licensee estoppel is considered. We are not persuaded that assignor estoppel requires any different rule. So no purpose could be served by a remand for an express ruling- on assignor estoppel on the facts of this case.