Dall Motor Parts Co. v. Packard Motor Car Co.

The defendant in error obtained a judgment in the trial court against the plaintiff in error for royalties claimed to be due upon a written contract between the parties, whereby the defendant in error granted to the plaintiff in error the right, not exclusive, to manufacture and sell an article upon the principle of which the defendant in error held letters patent.

Upon error to the Court of Appeals the judgment of the trial court was affirmed.

The defense of the plaintiff in error was that the letters patent were invalid because letters patent had been issued to other parties covering the same…