290 F. 647 | 7th Cir. | 1922
Use of fire brick in arches and baffles in furnaces was very old. In adapting for use in the fire boxes of locomotives the devices that were known in connection with stationary boilers, the question in each instance was whether the adaptation came from the ordinary advance due to the mechanical skill of the practitioners of the art, or whether there was an additional advance that came from the creative imagination of one who was therefore entitled to rank as an inventor. Of course, all doubts should be resolved in favor of patentees, and every shred of inventive progress should be protected. But the trouble is that no absolute yardstick has been devised.
On reviewing the record in this cause we are left with the conviction that the proper spirit of approach and method of disposition are evidenced in the opinion which led to the decree that is now affirmed.