City of San Francisco v. Union Tank & Pipe Co.

Appellee, as the holder of patent No. 1,-647,861, to Furey, brought this suit to enjoin infringement thereof. It covers a type of metal buttons or markers by means of which, when installed on street pavements, lines of travel are defined. For that purpose the appellant city was using a marker of a somewhat similar design. The statement of one of the three claims of the patent will suffice for all:

In view of the express limitation of the claims, the cancellation of broader claims in the course of patent proceedings, and the state of the prior art, appellee concedes that, assuming the validity of the patent, a point on which we intimate no opinion, it is “narrow,” and, in effect, that it is to be limited to the form of device disclosed. As shown in the patent drawings and as manufactured, appellee’s marker is made out of a square metal plate which is pressed into a slightly concave form and the comers turned down so that as “legs” they stand out at right angles from the convex surface. In putting it in place on the street, the legs are driven into the pavement, in the course of which process the force applied flattens the concave surface, with the result that the legs spread and…