United Parts Manufacturing Co. v. Lee Motor Products Inc‪.‬

The appellant, United Parts Manufacturing Company, is engaged in the manufacture and sale of replacement parts for motor vehicles, including hydraulic brake cylinders used in the hydraulic brake systems. It is the owner, by assignment from the patentee, of two patents, namely, Larson No. 2,412,587, issued December 17, 1946, hereinafter referred to as Larson 587, and Larson No. 2,435,837, issued February 10, 1948. These patents are concerned with a structure whereby leaky and defective hydraulic brake cylinders employed in the hydraulic brake systems of motor vehicles are restored to safe operating condition. Appellant brought this action against the appellees alleging infringement by them of these patents, seeking preliminary and permanent injunctions and damages. Appellees denied validity of the patents and infringement. The District Judge held that the claims of patent Larson 587 were invalid and not infringed by the appellees and dismissed the complaint. Larson No. 2,435,837 is an improvement over and a continuation in part of the earlier patent, and since its validity must stand or fall on the validity of the earlier parent patent, the case was tried and considered by the District Court, and will be considered on this review, on the merits of the parent patent, Larson 587.