Houston Oil Field Material Co. v. Claypool (269 F.2d 134, 1959)

TUTTLE, Circuit Judge.

This is an appeal from an interlocutory decree of the trial court sustaining the validity of claims 5 through 11 of Patent No. 2,698,761, and finding that all tools in suit made by appellants constituted infringement.

The findings of fact and conclusions of law, which set out the nature of the patent and the need sought to be filled by the alleged invention are reported at 166 F.Supp. 173, sub nom. Claypool v. Houston Oil Field Machinery Co. We shall therefore not repeat the findings and conclusions; nor is it necessary to discuss in detail the minute structural features of the devices of the parties. Briefly, the patent relates to a safety joint to be inserted in a string of production tubing in a gas or oil well, which is so constructed that it may be taken apart while thousands of feet below the surface of the ground by manipulation at the surface. This permits a skilled operator to disconnect and withdraw the tubing above such safety joint in the event such removal becomes desirable.

A safety joint that can operate only by the unscrewing of the threads by which it is connected to the tubing above or below it is unsatisfactory, and the court’s finding that there was need for a different disconnecting means is fully supported by the evidence.

Appellee’s device is designed to permit the upper part to be disconnected from the lower by the arrangement of a lug on the innerside of the lower part in juxtaposition with a corresponding slot on the surface of the upper member. This method of connecting and disconnecting pipes or tubing by use of a “