US1189276A - Circuit-interrupter. - Google Patents

Description

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UNITED STATES PATENT oPPICE.

JOSEPH N. MAPIoNEY, 0E WILKINSBUEQAND WALTER M. AUSTIN, or sWIssvALE, PENNSYLVANIA, AssIGNoNs To WESTINGPIOUSE ELECTRIC AND MANUFACTURING COMPANY, A CoIiPoRATIoN or PENNSYLVANIA.

CIRCUIT-INTERRUPTER.

Specification of Letters Patent.

Patented July 4, 1916.

Application filed September 28, 1912. Serial No. 722,933.

' providejaia,l device of the above indicated charl ,t1- shall be simple and durable in construction,-leifective and reliable inv operation aeter and that shall embody coperating main contact members and a plurality of sets of auxiliary Contact terminals to be disengaged successively during the opening operation of the interrupter in order that the final inter-Y ruption of the circuit shall be confined to the carbon arcing terminals.

Another object of our invention is to provide a circuit interrupter in which the carbon contact terminals are so constructed and arranged, with respect to the main contact members and other auxiliarycontact.terminals, as to be maintained in cooperative engagement during a portion of the opening operation of the interrupter to permit the separation of the other coperating Contact members and terminals to a suilicieiit degree to obviate the possibility of restablishing the circuit through an are which might be formed when the interrupter is finally opened.

Another object is to make provision for effecting a sliding or wiping action between the carbon terminals so that they may be kept free from dirt and a. good electrical contact may be secured, and a further obJect is to mount the carbon terminals so that they will be sel-alining. v

A still further object of our invention is to provide the auxiliary carbon .arcing terminals with conducting plates which are adapted toy cooperatively engage one another and which are electrically connected to the main Contact terminals by means of flexible contact membeis, thereby insuring a connection of relatively good electrical conductivity in shunt'to the main contact members. y

A still further object of our invention is to provide a set of intermediate auxiliary contact terminals in multiple relation to the main Contact members which are so arranged and 'constructed as to coperatively engage one another with any predetermined pressure at the instant that their engagement is eected. Moreover, these intermediate contact terminals are adapted to be brought into engagement with a sliding or wiping motion which serves to clean the contact surfaces. Furthermore, the disposition of the intermediate contact terminals and their Supporting means is such as to relieve the supporting f' means fromany undue strain or tendency-to buckle wliici might otherwise be caused in case of any slight roughness upon the cooperating Contact surfaces of the contact terminals.

Our invention may be best understood by 'reference to the accompanying drawing, in

which- Figure 1 is a View in side elevation of a portion of a circuit interrupter constructed in accordance with our invention, Fig. 2 is a view iii front elevation of aportion of the mechanism shown in Fig. 1, the movable carbon terminal and its supporting arm being removed for the sake of clearness. Fig. 3 is a detail view, in side elevation, of the retaining member shown in Figs. 1 and 2, and Figs. A and 5 are outline views of the coperating-carbon arcing terminals show-n in Figs. 1 and 2, illustrating the positions of'v the terminals and their associated parts during two successive stages in the opening operation of the interrupter.

Referring to the drawing, the device here shown comprises an insulating panel, 1, a main stationary contact member 2, a movable coperating contact member 3, a plurality of carbon arcing terminals l and 5 having cooperating contact plates 6 and 7, a supporting linkage 8 ior the carbon terminal Il, a supporting arm 9 for the carbon terminal 5, a stationary intermediate terminal 10 and a movable resiliently supported Contact terminal 11 to coperatc therewith.

The main contact member 2 constitutes a block having an integral stud 12 which projects through tlie insulating panel 1 and is suitably secured thereto, and the movable contact member 3 is of well-known construction and comprises a plurality of lamiii 13 of conducting material which are assembled in the form-of a. bridging brush and are suitably secured to a supporting arm 14. rlhe supporting arms 9 and 14 may `be pivotally mounted upon portions of the supporting structure (not shown) and may be operatively associated, the one with the other, 'through the agency of a suitable means embodying lost motion connection, such as is common to this art.

inasmuch as our invention pertains directly to the arcing terminals and has no particular relation to the usual operating mechanism of the circuit interrupter and other parts thereof which are essential to the construction of such a device, these parts are not illustrated or described, it being believed `that our invention may be well understood without illustration or description of these well-known parts.

Secured to the main contact member 2 and Yelectrically connected therewith is a supporting bracket 15 having a plurality of upwardly projecting arms' 16 between which one or more carbon arcing terminals 4 are mounted. The arcing terminal 4 comprises a block of carbon or other suitable material which is fastened rigidly to a member 17 by means of bolts 18 and 19. The lower front .portion of the terminal 4 is recessed and adapted to receive the contactplate 6 which is secured in position by' the bolt 19, the outer surface of the contact plate 6 and the carbon terminal 4 being in the same plane. The contact plate 6 is provided with an integral downwardly projecting extension 2O to which one end of a. .flexible conducting member 21 is attached, the other end of said member being fastened to the main contact member 2 in a manner that will be hereinafter set forth. Thus a path of high electrical conductivity is provided between the main contact member 3 and the tertiary contact plates 6.

The member 17 is provided with projecting side flanges 22, and a flange Q3 disposed between them and at right angles thereto. The outer surfaces of the several side flanges 22 are provided with recesses 24 and with holes 25. The recesses Q4, justreferred to. are adapted to receive the upper ends of supporting links Q6 that are pivotally secured to the flanges Q2 by means of pins 27, which project through the holesQ. The lower ends ofthe links 26 are pivotally Y mounted upon the supporting bracket 15,

through the agency of a rod 919 which projects through holes an said links and in the arms 16. M

The arms 16 are provided with laterallyl and inwardly projecting lugs 30 which are adapted to serve as stopsfor the links 26, and the forward movement of the carbon terminal 4 is also limited bytheengagement of the links 2.6 with the lower portions 31' of the recesses Z4, The backward movement of the links 26 and the contact terminal 4 is arrested by a strap 32 which is secured'to the arms 16 and extends the full width of the supporting bracket 15. Thus, the movement of the' links 26 and the terminals 4 is confined to prescribed limits, whereby the dcsired operation is insured.

One end of a resilient member 38 rests against the flange 23 of the member 17 and thereby maintains the arcingterminal 4 in engagement with its coperating contact member 5, as willbe readily understood. The other end of the resilient member 33 is attached to a portion 34 of the bracket member`15. A plate 3i; isfastened to the front edges of the jnojectingarms 16 and serves to protect and inclosc the flexible conductor 21 and the member 33.

The intermediate auxiliary contact terminal 10 is secured to the main contact member 2 by means of'screws 36, and the lower end of the ieziible conductor 21 is clamped between said terminal 10 and said contact member 2. l `urthermore, the contact terminal 10 is provided with a Contact surface 37 that is inclined at a suitable angle to the vertical, for a purpose to be herein'- manner, to the main supporting structure (not shown). The movable carbon contact terminal 5 is similar in construction to the contact terminal 4 and secured to the supporting arm 9 in much the same manner, by means of bolts 18 and 19, it being understood that the terminal 5 is rigidly attached to the supporting arm 9 and is not adapted for rotative movement. The contact plate 7 is associated with the contact terminal in a manner similar to that hereinbefore described. and the plate 7 is electrically con nected to the movable contact member 23, tlnough the agency of a flexible conducting member 3S.

The contact terminal 11, which is adapted to coperate with the stationary contact terminal 10 is mounted upon the free end of a resilient member 39, the other end of which is rigidly attached to the clamping plate 14. It is essential to the desired operation of the interrupter that the supporting member 39 be disposed in apj'noximatcly the same plane as the inclined contact surface 37 Iwhen the breaker is closed. An adjusting screw 40 is provided ii'rtermediate the ends of the resilient member 39 and is adapted to rest against the movable member 3, whereby the resilient member 39 may be maintained under any desired initial tension, so that a considerable pressure is exerted between the cooperating contact .terminals 10 and 11 when engagement thereof is effected.

Assuming that the various parts of the interrupter occupy the positions shown in Figs. 1 and '2 and that the restraining means (not shown) of the interrupter is released, the operation is as follows: rlhe supporting arm 14 and its associated contact member move outwardly about their pivotal support (not shown), thereby effecting the disengagement of the maincontact members Z and 3, it being understood that, as soon as these members are separated, the current traversing the interrupter parts is carried by the several sets of auxiliary contact terminals. After the separation of the main contact members 2 and 3, the intermediate contact terminals 10 and 11 are disengaged, thereby causing the contact plates 6 and 7 andthe cooperating .carbon contact terminals 4 and 5 to carry all of the current.

lVhile the separation of the main contact members 2 and 3 and the intermediate contact terminals lO'and 11 is being effected, the enti-re surface of the carbon contact terminal 4 is maintained in engagement with the cooperating surface of the carbon terminal 5 by means of the spring 33, which acts against the member 17. After contact terminals 1,0 and 11 have become disengaged, the arm 9, acting through the connecting means (not shown) begins to move outwardly and allows the terminals 4 and 6 to be, moved forward by the spring 33. During this operation, the terminals 4 and 5 ,and 6 and 7 are maintained in full engagementpuntil the links 26 are rotated about their pivotal support 29, and the movement thereof is arrested by the stops 30. It will, of course, be understood that, on account of the linkage mechanism 8 to which the carbon terminal 4 is secured, said terminal is slightly lowered in position durimT the first portion of the opening operation, the parts 4occupying the positions shown in Fig. 4 at a particular moment in the operation. As the supporting arm 9 continues to move outwardly, the carbon terminal 4 is given a rotative movement about its pivotal supports 27, thereby causing said terminal to tilt for ward and effect separation of the contact plates 6 and 7. Obviously, after the separation of the plates 6 and 7, all of the current is carried by the carbon terminals 4 and 5, which interpose a progressively increas-v ing resistance as the terminal 4 continues to tilt, thus preventing excessive arcing at the moment of final interruption. The forward rotative movement of the terminal 4 is limited by the engagement of the portions 31 of the recess 24 with the link 26, as already explained,

The structural details and the arrangement and location of parts, as well as the relative proportions thereof, are so chosen that the several sets of contact members and terminals are successively opened and, moreover, the main contact members 2 and 3 and the auxiliary contact terminals 10 and 11 and G and 7 are sui'liciently'r separated, prior to the final disengagement of the carbon terminals 4 and 5, to prevent the formation of an are between them at the instant of final interruption.

rlhe positions of the various parts are shown in Fig. 5 just prior to the disengagement of the carbon contact terminals 4 and 5. Subsequent to the disengagement, thereof, the movable parts of the interrupter are caused to be moved to their full. open positions, as will be readily understood by those skilled in the art.

in closing the interrupter, the supporting arm 9 is moved inwardly, and the circuit is first completed through the carbon contact terminals 4 and 5 inthe manner shown in Fig. 5. s the supporting arm 9 continues to be moved inwardly, the carbon contact terminal 4 is first given a rotative movement about its pivotal supports 27, whereby the contact terminals 4 and 5 are caused to engage each other throughout their entire contact surfaces, as shown in Fig. 4. As the closing operation proceeds further, the terminal 4 is forced inwardly against the spring 33, andthe links 2G are caused to rotate rabout their pivotal support 29 until said links are restricted in their movement by. reason of their engagement with the member 32. ft will be understood that, as the final step in the closingA o eration is et'- fected, the contact terminal 4 is moved up wai-illy, whereby a'sliding or wiping action is effected between the terminal members 4 and 5. Thus, a good electrical contact 'is obtai ned and the contact surfaces are cleaned and maintained in good operating condition.

Prior to the final closure of the interrupter, the intermediate contact terminal 11 is brought into engagement with the inclined surface 37 of the stationary terminal 10 and, by reason of the initial tension in the spring 39, the adjust-ment of which has hereinbefore been explained, a positive and definite pressure is at once established between the cooperating intermediate terminals 10 and 11. After the initial engagement of the terminals 10 and 11 and din-ing the remainder of the movement of the arm 14 and its associated contact member 3, a slidingor wiping action is produced between said terminals as the terminal 11 is moved upwardly along the inclined contact surface 37 of the terminal 10. As already explained, the resilient supporting member 39 for the terminal 1l is disposed in approximately the same plane as when the breaker is closed, and, consequently, in case the contact surface is rough and defective, by reason of severe arcing, the mechanical resistance to the n'iovement of the terminal 'l1 i-s exerted slibstantially in the plane of the member 39 .in the appended claims.

We Claim as our invention;

l. In a circuit interrupter, the Combination ivith relatively movable Contact members, of a link for pivotally supporting one of the Contact members, and a stop adapted to be engaged on one side by the link to limit its outward movement and adapted to be engaged on its other side by a projection on the contact member to guide and limit its rotational movement.

2. In a lcircuit interrupter, the combination 'with relatively movable main and auxiliary Contact members, of a doubly-pivoted supporting means for the auxiliary Contact member, anda single means for cooperating with the supporting means for limiting its outward movement and for cooperating With fthe auxiliary contact member for limiting its rotative movement.

3. In a circuit interrupter, the combination with relatively movable main and auxilia'ry contact members, of a doubly-pivoted supporting means for the auxiliary Contact member, and a lug for engaging the supporting means to limit its movement and for engaging the auxiliary contact member `-to limit its yrotative movement.

Lineare 4. In a circuit interrupter, the Combination with relatively movable main and auxiliary contact members, ot a rlouliily-pivoted supporting` means ttor the auxiliarlgf contact member, and a lug for engaging the supporting means to limit its movement and for engaging a projection on the auxiliary Contact member to limit its rotative movement.

5. In al circuit interrupter, tliecon'ibination with relatiif'ely movable main and aux; iliary contact members, of a pair of links for pivotally supporting the auxiliary cont-ae member on a common axis, resilient means for maintaining the auxiliary Contact members in engagement when the interrupl'er is closed, and two lugs, the auxiliary contact members being adapted to engage the lugs on one side and the links being adapted to engage the lugs on their other sides to limit the relative outward and rotative movements thereof, respectively.

6. In a circuit interrupter, the combination with relatively movable contact members, of a link for pivotally supporting one oit' the contact members, a spring for maintaining the Contact members in engagement .when the circuit interrupter is closed, and a single means adapted to be engaged on one side by the contact member and on the other side by the link to limit the relative outward and rotative movements thereof, respectively.

In testimony whereof, we have hereunto subscribed our names this 25th day ot Sept.,

IGSEPII N. lwII-IONEY. VALTER M. AUSTIN. Witnesses:

M. C. lvlnnz, B. B. IIINns.

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