GB363045A - Improvements in interlocking means between isolating switches, and the casings of switchgear and the like connected thereto - Google Patents

Abstract

363,045. Switchgear structures BROOKHIRST SWITCHGEAR, Ltd., Northgate Works, and LANCELEY, C., 12, Lime Grove, Hoole, both in Chester. Oct. 18, 1930, No. 31249. [Class 38 (v).] Snap-action switches; hand. actuating devices.-Interlocking means [between an isolating switch and the casing of associated switchgear is such, that before a handle-key can be removed from the isolating switch which it operates, it is necessary to lock the switch in its open position, and the same handle-key is used for locking the casing of the switchgear from which it cannot be withdrawn until the casing is closed and locked. To close the isolating switch A, Fig. 1, a handle-key K is inserted in a stem C and rotated through 90‹ to release a locking pin F, the pallet k1 moving first along an axial slot c1, and then along a circumferential slot c2 of the stem C, Fig. 11, and at the same time along an axial slot d1, and a circumferential slot d2 of a bush D, Fig. 13, in a boss on the isolating switch. The bush D has a second axial slot d3 so that the handle-key coupled with the stem C may be moved to close the isolating switch contacts a5 with a snap action ensured by springs a2, rollers a3 and cam plates a4. The handle-key K cannot now be removed until the switch is reopened, and the locking pin F again engaged. The switchgear casing is fitted with a lock comprising a rotatable quadrant t1, Figs. 15 and 16, which engages a fixed stop S. When the handle-key has been removed from the isolating switch it may be inserted in this lock, and turned to release the quadrant t1 allowing the door H to be opened. Immediately the door is opened a fixed pin R ceases to restrain a locking piece P which moves axially on a bolt m4 under the action of a spring p1, Fig. 19, to engage an abutment t2 on the quadrant t1, to prevent the latter from being turned while the door is open. The handle-key K cannot be removed from the casing lock until the quadrant is turned into its locked position because the pallet k1 engages behind the fixed casing m2 of the switchgear.