C. Martin Welch v. Eugene L. Grindle

This is an appeal from a judgment of the lower court that Patent No. 2,534,-644 is invalid and void. The patented article is a “Liquid Measuring Gauge,” commonly known in the airline industry as a “Fuel Tank Dipstick.” The trial court, having jurisdiction, held the patent invalid because:

(1) the application for patent was not filed by the true inventor;

(2) the application for patent was filed more than one year after public use of the patented article; and

(3) the patented article does not teach invention over the prior art.

Plaintiff-appellee (hereinafter called Grindle) and defendant-appellant (hereinafter called Welch) sued below by an original complaint for declaratory relief, alleging a justiciable controversy, because he (Grindle) had demanded an assignment of the Letters Patent to him; that Welch had refused to assign, and had threatened Grindle with suit if Grindle undertook the manufacture and sale of dipsticks incorporating the subject matter of the Letters Patent. By amended complaint, filed by permission of the trial court at the conclusion of the evidence (Fed.Rules of Civ.Proc. 15(b), 28 U.S.C.A.), Grindle alleged the organization of Deter jet Corporation, a…