Summerhays

The principal question in this case is whether infringement of plaintiff’s three patents in issue is clearly and definitely shown. As remarked in plaintiff’s brief, co-ordination of result, identity of means, and identity of operation must appear, and that defendant’s heater operated upon the same principle as plaintiff’s and achieved the same result in the same way. On a motion for preliminary injunction, infringement must be clearly and convincingly shown, without leaving in the mind of the court a reasonable doubt in relation thereto. Puller v. Yentzer, 94 U. S. 288 , 24 L. Ed. 103 ; A. B. Dick Co. v. Barnett (C. C. A.) 277 F. 423 . This rule arises from the fact that preliminary injunctions are granted on affidavits without defendant having had an opportunity to cross-examine the affiants, and therefore in many instances would, in effect, constitute determination of the issues before trial. National Cash Register Co. v. Remington Arms Co. (C. C. A.) 286 P. 367 . The rule doubtless has application even in cases where, as here, the assignee of the patent and those in privity with him are the asserted infringers of the assigned patent.

When it is attempted to establish…