GB129763A - Improvements in Electrical Oil Switches. - Google Patents

Abstract

129,763. Ferguson, Pailin, & Co., Ferguson, S., and Pailin, G. June 19, 1918. Automatic circuit-breakers.-A loose handle a movable in a vertical plane is connected to the operating-levers of an oil switch by the engagement of the forked end j of a lever i pivoted at h with a pin k on the handle, the forked lever being held in engagement with the pin by a trigger lever m adapted to be tripped either before or after the switch is fully closed. The main switchoperating lever g is connected by links f , f<1>, h<1> to a two-armed lever e pivoted to the framework at d. The trip mechanism comprises a lever r pivoted at sand connected to a rod t adapted to be raised by the armature v of the overload coil u, thereby causing the arm r<1> of the lever r to engage the trigger lever m and release the forked lever i. The rod t is provided with a knob x by means of which the rod may be raised to trip the switch by hand. A no-volt coil y is provided, the armature z of which, on failure of the current, raises a rod 3 carrying a disk 4 adapted to engage the knob x of the rod t. The operation of the switch by the no-volt coil is prevented until the switch is closed bv means of a rod 7 connected to a lever 5. On closing the switch, the lever e engages the end of the lever 5 and raises the rod 7 out of engagement with the disk 4 on the rod 3, thereby bringing the no-volt coil into operation. The armature z of the no-volt coil is held in the raised position by the rod 7 until the switch is closed, thereby enabling a smaller no-volt coil to be used. In the closed position of the switch, a spring-controlled catch 10 on the handle is held in engagement with a plate 11 on the framework by a rod 9 carried by the lever 5, so that the switch can only be opened through the trip mechanism, which can be operated manually by raising the rod 3 or by means of the knob x on the rod t. A shunt trip coil, operating in the same manner as the overload coil u, may be provided when it is desired to prevent the switch from being closed under certain conditions, e.g. until a starter is in the off position. The trip arm r<1> engages the trigger lever m at a point near its pivot when the switch is being closed than when it is actually closed, thus enabling the switch momentarily to take a heavier current during the closing movement without operating the trip mechanism.