US1069331A - Switching device. - Google Patents

Description

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SW-ICHING DEVECE.

Specification of Letters Patent.

lApplication filed October 7, 1908. Serial No. 4561513.

and State of Pennsylvania, have invented a new and useful Improvement in Switching "Devices, of which the followingis av specification.

My invention relates to switching devices .and it has special reference to knife-blade switches..

The 'object of my invention is to provide simple and inexpensive means which 'shall automatically open a knife-blade switch, in the event'ofa failure oi' thevoltage of the circuit in which it is included, and which shall not interfere with the manual manipulation o t the switch.

Automatic circuit `inerrupters of various types and sizes have heretofore been constructed for the purpose of automatically interrupting electric circuits under predeter-` mined conditions, such as overload, under-A load and novoltage rThese devices,how

ever, are relatively complicated and expensive, as compared with thev usual forms of imite-blade switches which are manually operated. Knife-blade switches are obviously unsuitable for interrupting a circuit which is traversed by relatively large currents or high voltages, on account of the detrimental eii'ect of electric arcs on such devices.

it is sometimes desirable to utilize a switching device which willA automatically interrupt the circuit upon the failure of the line voltage and,A according to my present invention, I provide a very simple actuating mechanism which is adapted for use 'with knifablade switches of the usual type and' Referring to Figs. `1 `and 2 of the drawging, the device here illustratedv comprises. a fdouble pole knife-blade switch .1 which is mounted, in the-usual manner, upon a slab {or base 2 of the insulating material and an lautomatic actuating mechanism 3 therefor, 'of which the operation of theknife blade .switch is normally independent.l The switch proper maybe constructed in any suitable manner-and may be provided with one or rammed Aug. 5,1913.

more poles, within the scope of my invention, the switch illustrated being composed of four 'stationary contact members 4, 5, 6, and 7, a pair of switch blades 8 and 9 that are pivotally mounted on the stationary contact members 4 and '5 and are adapted to engage the contact members Gand 7, an interconnecting or spacing block 10 of insulating material and an operatinghandle 11 secured thereto. v

The-actuating mechanism 3 comprises a twopart lever 12 pivotally mounted, atene end, on a' pin shaft 13, in alinement with the switch blade pivots, a lever 14, a pair of con- -necting links 15 and an electro-magnet 16 having a coil 17, a stationary core member 18 and a movable Vcore member or armature 19 one end of which is rigidly connected to move the armature downward, such as the magnetiopull when the coil is energized, holds the long arms of the lever substan-` tially in the vertical position in which manual manipulation of the-switch is permitted.

The stationary core member is supported in a box or bracket 2O which is secured to the insulating slab or base2 and the outer edge of this box is provided with pins 21 to which are attached the lower ends of springs 22, the upper ends of said springs being attached to the Vlong arms of the lever 12 which are adapted to 'engage the spacing block 10. The tensionin the springs, whenlthe switch is closed, is suicient to open the switch and interrupt the circuit when the electro-magnet is denergized.

Referringv to Fig. 3,. as here-shown, the switch blades are interposed in the respective sides of an electric circuit 23-24 and the coil4 17 of the electro-magnet is connected across said circuit. This coil ,is conse- .the line voltage fails; will be .denergzed With this ,arrangement, the 'actuating' lever will normally be held in'such a position that the switch may -be freely opened and closed. In some cases it may, however, bedesirable to connect` the coil of the magnet to the distributing circuit on lthe other side of the switch. With this arrangement,- the coil will always be denergized as soon as the' switch is opened and the actuating lever will follow the switch blade Whenever the switch is manually operated. The automatic operation of vthe switch will l be the same-in either case.

It is to be understood that' various structural modifications may be effected Wit-hin in which case the coil the scope of my invention, as dened in the appended claim.

claim as my invention: The combination with a., me, siede switch9 the movable member of which is orf mally unrestrained except hy. ricticn he v tween jaw and blade, of -a lever and a spring 'for forcing said movable lmeriiier to spew- FORD W. HARRIS.

Witnesses: 1

.FRED W. CLoUD, BIRNEY HINES.

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