US1189274A - Circuit-interrupter. - Google Patents

Description

H. 6. MACDONALD- cmcun INTERRUPTER.

APPLICATION FILED FEB. 15- l9l2.

Ptnted July 4, 1916.

ATTORNEY WITNESSES: dwL/m UNITED STATES PATENT OFFICE.

HGWARD G. MACDONALD, OF WILKINSBURG, :PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COMYANY, A CORPORATION OF PENNSYL- VANIA.

CIRCUITJNTERRUPTER.

Specification of Letters Eatent.

Patented July 4, 1916.

' Application filed February 15, 1912. Serial No. 677,865.

To all whom it may concern Be it known that I, HOWARD G. MACDON- ALB, a citizen of the United- States, and a resident of 'Wilkinsburg, in the county of.

Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Circuit-Interrupters, of which the following is a specification.

My invention relates to circuit interrupters and it has special reference to automatic tripping devices for this class of apparatus,

whereby the interrupters may be released erating conditions, such an arrangement opcrates satisfactorily. However, in certain cases Where it is found desirable to adjust the tripping mechanism to release the interrupter at a predetermined low current, suflicient energy is not imparted to the electromagnet to overcome the frictional resistance between the heavy parts of the operating mechanism and the restraining latch.

According to my present invention, 1 overcome the difficulty above referred to and accomplish a reliable and positive release of the interrupter by means of an auxiliary power device which is normally restrained in its set position and which may be automatically released by the usual tripping magnet to forcibly actuate and release the main latch of the interrupter. Moreover, the relative proportions and the arrangement of parts is such that, althdughconsiderablc energy, which is available for tripping purposes, is stored in the power device, an exceedingly small amount of energy is re quired to eflect its release.

My invention may best be understood by reference to the accompanying drawing of which Figure 1 is a View, partially in side elevation and partially in section, of a portion of a circuit interrupter. which embodies my invention and Fig. 2 is a detail plan view of parts of the operating mechanism cm bodied in my invention.

Referring to the drawing in detail, the device here shown comprises a plurality of stationary and movable contact members 1 and 2, an operating mechanism 3 for the movable members 2, a latch 4 for said operating mechanism, an operating handle 5, an auxiliary power device 6 and a tripping magnet 7.

The stationary contact members 1 are sup ported at the lower ends of suitable bushings 8, which are adapted to protect and insulate the main conducting members (not shown) from the. casing or cover'9 of a tank 10 in which the coiiperating contact members 1 and 2 are immersed in oil. The movable contact members2 are suitably supported upon a.cross arm 32in the usual manner. said cross arm 3 being attached to the lower end of a rod 11. The coiiperating contact members 1 and 2 are preferably of the usual butt-contact type, although any other suitable construction may be employed.

The operating mechanism 3 comprises a lever 12, one end of which is pivotally connectedto the upper end of the rod 11 and the other end of which is pivotally connected to the upper end of a guiding link 13, said link 13 being pivotally mounted upon a shaft 14.- which is carried by a bracket member 15 pertaining to the cover 9. The link 13 projects a short distance below its pivotal support 14 and is provided with a lug or projection 16, for a purpose to be hereinafter set forth.

A toggle for operating the movable con tact members 2 comprises a link 17 which is pivotally connected to the lever 12 at a point substantially midway between its ends, and an arm 18 constituting an integral part of a lever member 19 which is also mounted upon the shaft 14. A guiding link 20, which is pivotally connected to the lever 12 and to the upper end of a standard 21, serves to constrain the movements of the operating mechanism within prescribed limits.

Integrally associated with the lever 19 and its' arm 18, is a projecting member 22 that is provided with an adjustable stop 23 to cooperate with the projecting portion 16 of the link 13, whereby the pressurebetween the cooperating contact members 1 and 2 may be adjusted to any desired value.

A lever 24 is fixed to the shaft- 14 and its a latch 27 is provided which is pivotally inountedupon a pin 28that is carried by a suitable bracketinember 29, and said latch 27 is provided with a cateh 3( )to engage a suitable detent 3'1 that'is secured to the lever 24, substantially midway between its ends.

Integrally associated with thelatch 27 ,is a promotion 32 having a recess 33 to receive a spring 34 which is disposed therein and acts against a flange 35 of the. supporting bracket 29 in order to maintain the catch 30 in engagement with the detent' 31.

Furthermore, the-latch 27 is provided with an extension member 36 which projects he- -more fully set forth.

tween the respective-arms of a bifurcated portion 37 that is provided intermediate the ends of the lever 19. A pin 38 projects between the arms of the bifurcated portion 37 just referred to, and engages'the extension member 36 when the interrupter is closed. The extension member 36 serves as a cam during the opening operation of the interrupter and, by reason-ofits peculiar shape and its engagement, with-the pin 38, therelease of the catch 'from the detent 31 is eflected when the. lever 19 moves to its upper position, as will be hereinafter The operating'handlefi preferably located outside'of a casingi39 which cnvelops and protects theoperating. mechanism 3 and the auxiliary powerdevice '6, and is. rigidly Secured to the shaft. 14, while a counter weight-40 isrigidlj connected to said shaft by means of anarm 40" to bring the operating handle 5 and thelever 24 to their upper positions when the interrupter is released.

The auxiliary power device 6 comprises a bell crank lever 41 that is pivotally mounted upon a pin 42 and a coil spring'43, the

' ends of which are respectively connected to the upper end of an arm 44 ofthe bell crank lever 42' and to a project ng member 45 which constitutes a part of the'supporting bracket 29. The free arm 46 of the bell crank lever 41 has a pin and slot connection 47 with a rod or striking member 43 that is located beneath an arm 49 of the main latch 4 and is adapted to actuate the same.-

The bell crank lever 41 is restrained in its setposition by means of a latch 50 having an arm 51 to be engaged by a striking member or rod 62 that is associated with a movable core member 53 of the electromagnet 7, said magnet being also provided with a stationary core member 54 and an exciting winding or coil 55, in accordance with the usual practice.

It will be notedthat the main arm 44 of the bell crank lever 41'and the coil spring 43 aredisposed approximately in a line, the one withthe other, so that the belle-rank lever 41 may be regarded as restrained in a prox'imatelyits dead center position ence, although considerable energy may be stored in the-spring 43, the bell crank lever 41 may be restrained in its set position and released therefrom by an exceedingly small amount of energy. Manifestly, when the bell cranklever 41 and the spring 43 are released, the lever arm: through. which the spring 43 acts, rapidly increasesso that the striking member 48 is projected with considerable force against the arm 49 of the latch 4, whereby a positive release of thelever 19 iseflected.

In order to reset theyauxiliziry power device 6 during the opening operation of-the interrupter, a link56 is provided, the lower end of which is pivotally'conuectedto the upper end of the bell crank lever 41, while the upper end thereof has a pinand slot-connection 57 with the lever 24. In order to permit of manualtripping of the interrupter, a tripping rod 58, having. a handle or button 59, is provided, and is so located with respect to the latch 27 that said latch may be manually operated when desiredQ Assuming the. various parts of the interrupter to occupy. the position shown, manual i release may be accomplished the manner hereinafter described;

-' The rod 58' isfirst .pus'lied i .ipwardly',". thereby engaging the latch '27and'withdrawing the catch v30 from thedetei'it 31'. Thus, the operatingmechanisiiiis released and the operating toggle, comprising thelink '17 and the arm 18, is allowed to-collapse, there-'- by permitting the separation. of the cooperating'contact members 1 and 2 by realevers 19 and 24, which are still locked together by the latch 4', as well as-the operating handle 5, are moved upwardlyin a clockwise direction,"to their upper positions, as indicated in dot and dash lines. No move ment of the bell crank lever 41, however, is

effected during this operation. by reason of the lost-motion ,or'pin and slot connection 57 which has already been referred to. In

order to reset the interrupter, it is only' necessary to move the handle-5 downwardly,

. thereby forcing the operatingtoggle, comprisingthe link 17 and the arm 18, into its set position and thus raising the movable contact members 2 into cobperative engagement with the stationary contact members 1. When the associated levers 19 and 24 are in their lower positions, the latch 27 again serves to restrain them, as hereiniiefore-set forth. H

Assuming that sullicient current traverses soil of the action of gravity. During the .opening. operation of the interrupter, the

restraining said lover, a striking rod operntivoly assooiatwl. with the free arm of said lever by a pin and slot connection for rolensing said restraining moans and electroresponsive means for releasing said latch. (3. ln a circuitintorrupter, the combination with cooperating stationary and movnhlo oontuut members, an oporuting mechanism for said movable Inclllbfir embodying tam pivotally nlonntotl relatively movable opvrnting lovers, and means for iPStl'fllIliDg' mid. operating iliflliRIliSIil, of a pivotally mounted l'wl crank m'or illnt; gm-mm with one of the arms thereof for actuating said lever, a latch for restraining said lever, a striking rod operntivel) connected to the free arm of said lever for releasing said restraining means, and electro-responsive moans for releasing said latch.

In testimony whereof, I have hereunto subscribed my name this 13th day of Feb. 1912.

HOV/ARI) G. MACDONALD.

Witnesses D. H. MACE, B. B. Hmns.

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