Electric Cable Joint Co. v. Brooklyn Edison Co., Inc. - 292 U.S. 69 (1934)
U.S. Supreme Court
Electric Cable Joint Co. v. Brooklyn Edison Co., Inc., 292 U.S. 69 (1934)
Electric Cable Joint Co. v. Brooklyn Edison Co., Inc.
Argued March 15, 1934
Decided April 2, 1934
292 U.S. 69
1. Claim 4 of Patent No. 1,172,322, to Torchio, February 23, 1916, for an improvement in protective devices for electric cable joints, held invalid because of the prior art and for want of invention.
2. The claim is for a device, in combination, for improving insulation at joints of high-tension metal-sheathed cables. The conductors in such cables are insulated from the sheath and from the metal sleeves by which the sheathing is continued at their junctions, by wrappings of pervious material saturated with an insulating oily substance. Migration and loss of this substance, caused by cutting
a cable, and, more especially, by its contraction and exspansion, or " breathing," when in operation at high voltages result in air spaces within the insulation through which damaging leakages of current take place. The elements in the combination claimed to be new are: (1) the use of an insulating liquid (oil) which is fluid at ordinary working temperatures of such cables, in lieu of compounds of higher melting point, and (2) a reservoir holding a supply of such liquid and commulicating with the interior of the joint.
The Court finds (1) that use in the combination of the more fluid insulating permeant was anticipated in the prior art and fully disclosed in publications; (2) that the addition of the reservoir was also anticipated, besides being a mere mechanical adaptation. Pp. 292 U. S. 72-79.
3. Invention may consist in adding a new element to an old combination, but the addition must be the result of invention, not the mere exercise of the skill of the calling and not one plainly indicated by the prior art. P. 292 U. S. 79.
66 F.2d 739 affirmed.
Certiorari, 290 U.S. 624, to review the affirmance of a decree denying the validity of a patent in a suit by an assignee claiming infringement.