GB974763A - Improvements in or relating to locks - Google Patents

Abstract

974,763. Latches. LOWE & FLETCHER Ltd. Aug. 17, 1961 [Sept. 16, 1960], No. 31889/60. Heading E2A. A fastening arrangement, particularly for use in locking the door of a cabinet containing high voltage electrical equipment, comprises a projection 12 mounted on the door and adapted to co-operate with the part 11 of a member 10 mounted on the frame of the cabinet, this latter member 10 also comprising a locking device 15, of the type described in Specifications 940,428 and 940,429, for locking the components of the part 11 in such a manner that the projection 12 may not be withdrawn therefrom. The locking device 15 is operated by a handle 27 which is detachable therefrom, but only when the door of the cabinet is closed and the device 15 has been actuated to lock the member 11, the handle then being inserted in an isolating switch to complete the electrical circuit containing the apparatus housed within the cabinet. The handle may not be withdrawn from the switch until the latter is in its open position, so that the door of the cabinet may not be opened until the electrical supply to the apparatus therein has been disconnected. The part 11 of the member 10 comprises a cylindrical housing containing four discs 17 rotatable about a common spindle 25, each comprising slots 18 and 19 and each spring-biased in such a manner that the four slots 18, and the four slots 19, are normally out of register. As the door of the cabinet is closed, the projection 12 enters an aperture 20 at one end of the housing, and its surface co-operates with each of the slots 19 in turn to bring the latter into register, the arrangement being such that the slots 18 are simultaneously brought into register. The locking device 15 is then actuated by the handle 27 to engage a bolt 25 in the slots 18, thereby holding the discs 17 in their projection-engaging positions.