Cutler Mail Chute Co. v. Capitol Mail Chute Corp.

SWAN, Circuit Judge.

This is an appeal 'in a patent infringement suit in which the usual defenses of invalidity and noninfringement were set up by the defendant. Both issues were determined in the plaintiff’s favor by the trial court and both are disputed by the appellant here.

The patent in suit is for an improvement in mail chutes of the type commonly used in office buildings to conduct letters deposited at the several upper floors to a mail box at the bottom of the chute. The specifications state that experience has shown that mischievous or careless persons are likely to drop matches,…