Security seal and lock

摘要

A preferably cast zinc housing has a chamber for receiving a metal stranded cable +E,fra 1/16+EE inch in diameter which is swaged at one end to the housing in the chamber. The housing has a conical bore in communication with the ambient about the housing via apertures at opposing ends of the housing. A channel having a depth of about one half the cable diameter is in the bore surface aligned with the apertures to form a continuous cable insertion path with the apertures. A relatively weak coil spring and a pair of different diameter steel balls are in the conical bore. The cable free end is inserted into the path through the housing with minimal insertion resistance from the balls and spring. Withdrawal of the cable wedges the balls uniformly against the cable deforming it and locking the cable to the housing. The balls each uniformly stress the cable to spread the stress of the wedging action. This reduces stress concentration on the cable at each ball so that the cable fails only at its maximum tensile load.