Westinghouse Air Brake Co. v. Christensen Engineering Co.

LACOMBE, Circuit Judge.

This suit was brought to enjoin an alleged infringement. Upon proofs showing the type of valve which defendant had manufactured and sold before suit brought, it was held that such type did not infringe the patent under the restricted construction given to it by the Supreme Court (Westinghouse v. Boyden Power-Brake Co., 170 U. S. 537 , 18 Sup. Ct. 707, 42 L. Ed. 1136 ), and that defendant’s device was similar to the Boyden valve, possessing a structural feature which that court held differentiated the Boyden valve from the valve of 360,070. Since then defendant has so modified its valve as to eliminate the feature which differentiated it, and it is thought that as now constructed it infringes 360,070, as construed by the Supreme Court.

When an infringing device is shown to have been made before suit brought, the charges of the bill will be held broad enough to cover subsequent changes of structure which also infringe, and successive preliminary injunctions may issue to cover each and all of such modified forms. But no authority is called to the attention of the court which holds that where no infringement is shown before filing of the bill, and no threat to infringe is proved by evidence of an intention then to manufacture a particular structure, which the court can see will infringe if it be made, a subsequent change of structure, which transforms a noninfringing into an infringing device, will warrant the issuing of a preliminary injunction. There are several cases which hold the other way. Humane Bit Co. v. Barnet (C. C.) 117 Fed. 316 ; Slessinger v. Buckingham (C. C.) 17 Fed. 454 ; Judson Mfg. Co. v. Burge-Donahue Co. (C. C.) 47 Fed. 463 .

The motion is denied, with leave to renew after defendant shall have applied for and obtained leave to file a supplemental bill.