Angle

The complainants, Anna Hopkins Angle and The S. S. White Dental Manufacturing Company, a corporation, are respectively owner and exclusive licensee of letters patent No. 1,584,501, granted May 11, 1926, to Edward H. Angle for “Orthodontic Appliance.”

On April 2, 1934, they filed their bill in equity against Sidney Richardson as defendant, to restrain infringement by him of said patent and for an accounting. By his answer filed herein on May 14, 1934, the defendant raised issue by averring:

1. That the patent is invalid in the light of the prior art.

2. That Edward H. Angle was not the inventor of the device patented and that he wrongly obtained the patent.

3. That the defendant has not infringed the patent.

4. That because of the pendency of an action for an accounting in a state court in California, this suit was wrongfully and inequitably brought.

Thereafter, pursuant to leave, and on April 15, 1935, the defendant filed an amended and supplemental answer, renewing the defenses earlier pleaded, and asserting therein further defenses to complainants’ bill, among which is the grant on October 9, 1934, to defendant and one Charles Edward Boyd of letters patent No. 1,976,141;…