Richard Irvin & Co. v. Westinghouse Air Brake Co.

It is clear that the defendant does not infringe the only claim in suit, No. 10. In the first place the purpose of the only parts of the A. B. Brake which are alleged to infringe was quite different. Heiniger’s pressure retaining valve was designed to keep pressure in the brake cylinder while pressure in the auxiliary reservoir was being built up. In the defendant’s brake an emergency application — in which phase alone the A. B. Brake is supposed to infringe — results in emptying the brake pipe line at once, and the delay in exhausting the brake cylinder is not in order to give time to build…