GB246403A - Improvements in or relating to combined electric switches and electric couplings - Google Patents

Abstract

246,403. Crabtree, J. A. Sept. 14, 1925. Plug couplings combined with switches. In a switch-coupling of the type in which a plunger or slide locks the switch in the open position when the plug is withdrawn, an obstruction is arranged to prevent displacement of the plunger by means other than the plug. In the form shown in Fig. 1, a slide b coupled to the arm of a tumbler switch a, is slotted and notched as shown in Fig. G, so that the earthing pin d of the plug can be inserted into the socket e only when the switch is open, and a spring-pressed plunger k sliding on a pin l normally occupies the notch and locks the switch; the pin d which is then longer than the others is made hollow so as to pass over the obstructing pin l, and is grooved at o so as to permit the necessary movement of the slide b for the closing of the switch, at the same time locking the plug in position till the switch is opened. The socket e is positioned by a plate f which forms a guide for the slide b, and is connected to the bridge i of the switch and an earthing terminal. In a modification a bar is fixed across the mouth of the socket e, and the pin d is correspondingly slotted. Specification 248,496 is referred to.