BOWELL V. LINDSAY. 297 �ihe patent it the substitute perforais the same functions and was well known at the date of the patent as a proper substi- tute for the omitted ingredient ; but the rule is otherwise if the ingredient substituted was a new one, or performs a sub- stantially different function, or was not known at the date of the plaintiff 's patent as a proper substitute for the one omitted from his patented combination. Where the defendant, in construoting his machine, omits entirely one of the ingre- dients of the plaintiff's combination without substituting any other, he does not infringe ; and if he subatitutes another in the place of the one omitted, which is new, or which per- forms a substantially different function, or if it is old, but was not known at the date of the plaintiff's patent as a proper substitute for the omitted ingredient, then he does not in- fringe." See, also, GUI v. Wells, 22 Wall. 1. �It follows, therefore, from these statements of the law, that if the defendants omit entirely one of the elements of the complainants' combination without substituting any other, or if they substitute another which is new, or which performs a substantially different function, or if it is one that is old, but was not known at the date of the complainants' patent as a proper substitute for the omitted ingredient, or if their machine consista in a new combination of the same ingredi- ents, then the defendants do not infringe. A material ingre- dient of complainants' device is the curved brace-bar, welded to the shank of the tooth. This cannot be denied. If the defendants, omitting the brace-bar, have substituted an ele- ment in its place, that substitution consists not in supply- ing by physical addition another part, distinct from the rest of the device, in the place of that omitted, but in merely changing the form of the head of the shank where it rests in the mortise in the beam. In the complainants' device th& curved brace-bar is welded to the rear of the shank about midway between the point where the shank is pivoted to the^ beam and the tooth, and passes into the mortise at the end of the beam, where it may be clamped. As before stated, the tooth and shank of defendants' device consist of a single piece of metal ; the head of the shank, where it passes. ��� �
