Citations
- 11 F.2d 810
Full opinion text
SCHOONMAKER, District Judge.
This is a patent suit, charging infringement of plaintiff’s patent No. 1,150,415, issued August 17, 1915, to the plaintiff as assignee of the inventor, H. B. Bishop, upon application filed August 8, 1911, for improvements in the manufacture of hydrofluoric acid. The plaintiff also asserts that the defendant is the owner of two patents taken out by Mr. Fiekes, Nos. 1,288,400 and 1,316,569, which patents the plaintiff alleges interfere with the plaintiff’s patent. For that reason, the plaintiff, in its bill of complaint in this ease, has asked proper relief under section 4918 of the Revised Statutes of the United States.
The art of making hydrofluoric acid is an ancient art. It has long been known that when fluorspar (calcium fluoride, CaF2) is caused to react with sulphuric acid (H2SO4), hydrofluoric acid gas (HF) will be given off, leaving a residue of calcium sulphate (CaSO