Page:Federal Reporter, 1st Series, Volume 7.djvu/781

OOKSOLIDATBD'/IETG.» kJO.' ». CROSBY, ETC., 00. 76O �valve went into general use upon the locomotives of this coantry and of Europe, immediately upon its introduction to thio market, and is still made and sold very extensively. The defendant holds two patents granted to George H. Crosby, one dated January 26, 1875, No. 159,157, and the other dated February 23, 1875, No. 160,167. The questions ar- ^ed' in these cases are whether Eichardson's patents are valid, and if they are, whether Crosby's patents represent subordinate or independent inventions. �The plaintiff 's invention has been twice befcire this court. In Ashcroft v. Boston e Lowell B. Go. 1 Holmes, 366; the owner of the safety-valve patented by Naylor, in 1868, sued to enjoin the use of the Eichatdson valve ; but the court held that the two were distinct inventions. This decision was affirmed in the supreme aonri, {Ashcroft y. Railroad Co. 97 U. S. 189.) Another suit, in which Eichardson was Jjlaintiff and Ashcroft defendant, was pending at the same time, upon the same evidence, and was decided in January, 1875, in favor of the plaintiff. Judge Shepley's opinion was orally given, and no minutes of it are preserved. From the reports of the former case, and the additional testimouy in this record, the state of the art is ptetty fully exhibited. The ordinary safety-valve still used upon certain kinds of boilers, and which consists of a valve kept down by a lever and weight, or by a spring balance, was not wholly satisfactory, nor always even safe when used with a helical spring, which is much the most convenient load for the valve of a locomo- tive. When steam is made very rapidly, this valve will not open f ast enough to reduce the pressure of the boiler, because the pressure of the spring is constantly increaSing by its compression. To meet this difficulty, several inventors, before 1866, constructed and patented valves which bad an additional surface, outside of the valve proper, to be acted on by the steam as soon as it bad raised the valve, and thus to increase the lift as the force of the spring increased. Naylor's specification, as cited by Judge Shepley, 1 Holmes, 368, deseribed a valve which was made to project over the edges of the exit passage for the steam, and the projecting ^ v.7,no.8— 49 ��� �