Patent GB-190988-A (GB)
Title: Apparatus involving the use of a number of electrical cut-outs
IPC: H01H85/28
Filed: 1921-09-26
Abstract: 190,988. Illingworth, W. H. Sept. 26, 1921. Mercury cut-outs; automatic circuit-breakers; oil switches; switch mechanism interlocking with lids.-A number of mercury cut-outs of the kind in which the expansion or breakage of a mercury column lifts an operating member, are combined in such a manner that operation of one cutout either effects the simultaneous operation of the others, or, according to a modification, releases trip gear for breaking an oil or air break switch. The cutouts are modifications of those described in Specification 190,096. Figs. 1 and 2 show the invention applied to a three-phase alternating current, there being three cut-outs each attached at its top to a slate J. On an excess current occurring in any cut-out, the mercury column within is broken, and caps d<2> and f<3> are forced up and down respectively. The caps d<2> are connected by levers to a common spindle d<20> so that the other cut-outs are simultaneously operated. The cut-outs may also be released by hand or by a no-volt coil N, pressure on a knob M or the fall of a core n effecting rotation of the shaft d<20>. Resetting of the cutouts is effected by a handle L which rotates two linked shafts f<11> and d<21> carrying cams f<12> and d<22> which press together the caps d<2> and f<3>. An indicator m<5> indicates whether the cut-outs are " on " or " off " and a locking device k prevents the door of the casing being opened when the cut-outs are in operation. Fig. 6 shows the invention applied to a three-phase oil switch, a cutout in which there is no movement of the bottom cap being used. Operation of anyone of the cutouts causes its cap d<2> to lift its lever d<23>, so turning a shaft o<12> and raising three catches o<11> from engagement with three cross-heads o<5>. A spring-pressed lever o<15> then presses each cross o' downwards and moves the switch blades o of the oil switch out of contact. Resetting of the cut-outs is effected automatically by levers d<27> which are actuated by the fall of the cross-head o<5>. The arms d<23> then fall into their original places and the switch may be closed by the bandle L which rotates the shaft o<16>. The switch may also be opened by hand or by a no-volt coil N, pressure on the knob M or the fall of a core n serving to disengage the catch o<11>. An arm k fixed to the shaft o<12> prevents the door k<2> from being opened without the knob M being first pressed. An indicating lever o<23> is operated by an arm o<21> loosely pivoted on the shaft o<12>, the arm o<21> having an extension o<24>, Fig. 6<A>, which has a link connection with an arm o<28> on the cross-head o<5>. The oil tank k<4> has a safety valve k<10> and is detachable; but when the switch is " on " disconnection is prevented by catches on the tank engaging abutments on the sliding rods which carry the switch contacts. The handle L, Fig. 4, is loosely mounted on the shaft f<11> and drives it by means of a pawl l engaging a toothed cam l<1> fixed to the shaft. The pawl l also engages a slot l<3> which causes it to become disengaged from the cam at the end of the stroke, thus allowing the cut-outs to act again even though the handle is held.