Patent GB-235319-A (GB)
Title: An interlocking-arrangement for two or more devices, applicable, for instance, to electric switch-gear
IPC: H01H33/52
Filed: 1924-03-14
Abstract: 235,319. British Thomson-Houston Co., Ltd., and Wood, C. W. March 14, 1924. Oil switches; switch mechanism, interlocking with lids; bases and cases; switches, locking.- In electric switch gear of the kind wherein a key is available for unlocking a sliding or hinged door or cover only when certain apparatus is locked in predetermined position and is withdrawn from the door or cover when the same is locked, means are provided for positively preventing the key from being turned into locked position so long as the door or cover is open. In Figs. 1 and 2, an isolating switch mechanism is connected to a lever 11 pivoted by means of a hub 12 to a shaft 13, the hub 12 having an aperture 17 for receiving the operating implement. A shutter 18 normally covers the aperture and is mounted on a disc 22 for rotation about the shaft 13, the disc carrying a trip-lever 21 for the associated circuit-breaker. Pins 23 on the disc 22 are adapted, when the shutter is rotated to uncover the aperture, to move so as to separate, two links 25, in which position the breaker has been tripped by the lever 21 and the disc 22 latched by a lever 29 against the action of a spring 27 tending to restore it. The isolating switch can now be opened by inserting the implement in aperture 17, so rotating hub 12 until an aperture 42 therein moves into the line of action of a bolt 41 operated by a lock 35 and key 36, the latter being only removable from the lock when the bolt 41 has been shot to lock the isolating switch open. The lock may be of ordinary construction provided the rotation of the key is less than 360‹. When the key is removed it is available for use in the lock of the chamber-door, of which one 43 is shown in Fig. 3 and is slidable in front of side walls 44. In the closed position shown, the lever 45 on the lock-shaft 37 engages a plate 47 on a wall (not shown) and the door is prevented from being opened. The key is adapted to be only inserted when the lever 45 is locked, operation of the key rotating the lever until a block 48 thereon moves clear of the plate 47 and the door may be opened. During the latter operation a fixed pin 49 engages the lever 51 which lifts a latch 55 into a position such that operation of the lock, and therefore removal of the key, is prevented while the door is open. In the door or lid 57 shown in Fig. 4, the latter effect is obtained by a latch 69 engaging a part 73 of the locking-lever 66, the engagement being effected by interaction of a fixed-and-movable cam device 63 operated by the lifting of the lid. Several doors 76, Fig. 5 may be locked by a bar 77 having a pin-and-slot connection with a locking bar 81 controlled by three locks 35, each of which must be unlocked to allow movement of the bar 81 to unlock the doors. In the open position, the bar 77 engages the tops of the doors and prevents locking the locks and removing the keys. The locks are shown in Figs. 6 and 6<a>, from which it can be seen, the bar 81 has slots 87 engaged in the locked position by locking members 88 having slots 89 which are arranged to be aligned with the bar 81 when all the keys are inserted and turned through 60‹. The bar is then movable and its full width then occupies the slots 89 to prevent the locks being turned.