Rown

Below, the appellees and the appellant were, respectively, plaintiffs and defendant, and herein they will be so designated. One of the plaintiffs is the owner of Brennan patent, No. 1,264,770, and the other is a licensee thereunder. The defendant, who, in his automobile shop at San Francisco, uses a brake-testing device, known as the “Jumbo,” and manufactured by the Price-Hollister Company of Rockford, 111., is sued upon the ground that he thus infringes the patent. The only claim presently involved is No. 1, which the lower court held valid and infringed. It is as follows:

The patent issued April 30,1918, upon an application filed April 24,1916. In his specifications the patentee declared that his “invention relates to a brake-testing device, particularly designed for testing the brakes of an automobile,” and that its object “is to provide a simple and inexpensive device for the purpose which may be readily applied either in a garage or elsewhere to determine whether or not the brakes are in proper working condition.” Pointing out the danger of operating ears with imperfect brakes, particularly in urban communities, he asserted that the only known means of discovery of defects…