Hughes Blades, Inc., a California Corporation, and Norman P. Van Valkenburgh v. Diamond Tool Associates

In this action, brought by appellants for patent infringement, a summary judgment was entered in favor of appellees upon the ground of lack of invention. The court concluded that the only substantial addition which the patents involved had made to prior art “would have been obvious to a layman, let alone to a person skilled in the * * art.”

Involved are Patent No. 2,763,258, issued to appellant Hughes Blades as assignee on September 11, 1958, and Reissue Patent No. 24,562. It is claimed that appellees have infringed Claim No. 5 of the patent and Claims Nos. 5, 12, 13, 14 and 15 of the reissue patent.

These patents relate to an improvement in the construction of circular saw blades in which the cutting edge (consisting of cutting elements composed of compressed metal and diamond particles) is mounted upon the peripheral edge of a softer circular disc-like core of metal. The record demonstrates that a problem encountered in the art was that such blades, when cutting such substances as concrete, suffered wear and tear at the peripheral edge of the core to which the cutting elements were attached, which caused the cutting elements to drop off before they had themselves enjoyed their…