Foltz Smokeless Furnace Co. v. Eureka Smokeless Furnace Co.

• Decision Date: 21 January 1919
• Docket Number: 2637.
• Citation: 256 F. 847
• Parties: FOLTZ SMOKELESS FURNACE CO. et al. v. EUREKA SMOKELESS FURNACE CO.
• Court: U.S. Court of Appeals — Seventh Circuit

256 F. 847

FOLTZ SMOKELESS FURNACE CO. et al. v. EUREKA SMOKELESS FURNACE CO.

No. 2637.

United States Court of Appeals, Seventh Circuit.

January 21, 1919

Rehearing Denied March 4, 1919.

William R. Rummler, of Chicago, Ill., for appellants.

Max W Zabel, of Chicago, Ill., for appellee.

Before BAKER, ALSCHULER, and EVANS, Circuit Judges.

ALSCHULER Circuit Judge.

Appellant Foltz made application in March, 1915, for a patent on certain new and useful improvements in furnaces of which he claimed to be the inventor.February 16, 1916, he sold and assigned in writing to appellee corporation (of which he was then a stockholder) his 'entire interest for the United States in and to improvements described in my applications for United States patents as follows,' enumerating this application, among others.Some time prior to the assignment the Patent Office rejected, on the prior art, all of the claims made.After the assignment, but without further affidavit by Foltz or knowledge on his part, the assignee caused new claims to be filed, which eventuated in the issue July 31, 1917, of patent No. 1,235,516, with 10 claims as therein set forth.The drawings of the original application remained unchanged, and the description as first made was unaltered, save in minor details which are here unimportant.

September 1917, Foltz organized appellant corporation, of which he was president, treasurer, general manager, and controlling stockholder, and they began the manufacture of furnaces which infringed claims 7, 8, 9, and 10 of the patent.Appellee filed its bill against appellants for injunction and accounting.On the hearing appellants offered testimony to show that Foltz was not the inventor of the thing described in claims 7, 8, 9, and 10 of the patent, and offered in evidence copies of prior art patents, on the theory that they tended to establish the invalidity of those claims.On appellee's objection all such evidence was ruled out, on the ground that appellant, as assignor of the application for the patent, was estopped as against his assignee from questioning its validity.Such ruling of the District Court constitutes ground of the appeal from the decree granting the relief prayed.

The general rule of estoppel upon the assignor of a patent to deny its validity as against his assignee is too well established to require more than its statement.We see no reason for relaxation of the rule where the...