US2411894A - Arc extinguishing chamber for circuit breakers - Google Patents

Description

. 3, 1946. G; w. PETERS 4 ARC EXTINGUISHING CHAMBER FOR CIRCUIT BREAKERS Filed Feb. 9, 1944 2 Sheets-Sheet 1 -MoqA/fr Dec. 3, 1946. G. w. PETERS 2,411,894

ARC EXTINGUISHING CHAMBER FOR CIRCUIT BREAKERS Filed Feb. 9. 1944 2 sheets-snee: 2

0 5 Z 6 2 4 3 f \4\\( A ////////////J///J///////////// leraar/NG 256mo-m7 Patented Dec. 3, 1946' ARC EXTINGUI'SHING CHAMBER FOR CIRCUIT BREAKERS Gerhard W.Peters, Akron, Ohio Application February 9, 1944, serial No. 521,613

My invention relates in general to electric switches and more particularly to quick-acting circuit interrupting switches which may be actuated electro-magnetically or otherwise.

An object of my invention is the provision of a split insulating housing having an arc chamber for an electric switch having stationary contact means mounted upon one ofthe parts of the split housing and having the movable contact means projecting into an opening through the other part of the split insulating housing, the contact means and the split insulating housing means being so arranged that when the part having the opening therein is removed, the stationary contact means becomes readily exposed and accessible for inspection and replacement.

Another object of my invention is the provision of preventing the removal oi one of the parts of the split insulating housing when the movable contacts are in their operative motion transmitting position.

Another object .of my invention is to prevent` the removal of one of the parts oi the split insulating housing the motion transmitting means which operate them are tlrst removed.

Another object of my invention is the provision of resilient means interposed between the movable contact means and the actuating mechanism, the resilient means being so disposed that it is mounted externally of the insulating housing to be free from the arc in the insulating housing.

Another object of my invention is to prevent the movable contact means during the circuit interrupting movement from being withdrawn from the opening in the insulating housing in which the movable contact means operates.

Another object of my invention is the provision rst separated in the large chamber, after which the movable contact immediately moves into the small chamber, the movable contact being arrest ed in its separating movement in the small cham ber, or at least prior to a point where the area between the movable contacts and the side wall of the small chamber equals the cross-sectional area of the small chamber. J

Another object of my invention is to provide a housing having a large chamber in which the stationary contact is mounted and having a smaller chamber connecting the large chamber with the outside of the housing forming an opening through which the movable contact is actuated to engage the stationary contact.

unless the movable contacts and 3 Claims. (Cl. 20D-144) 2 Another object of my invention is the provision of detachably removing the movable contact means without removing the insulating housing. Other objectsand a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a top view of a switch embodying the features of my invention;

Figure 2 is a front elevational view of the deviceshown in Figure 1 with certain parts broken away to illustrate more clearly the construction of the arc chamber and the stationary contacts;

Figure 3 is a side elevational view of the device shown in Figure 2, taken along the line 3 3 thereof;

Figure 4 is a view similar to Figure 3, illustrating the manner in which one of the split parts of i the insulating housing is removed; and

Figure 5 is a view along the line 5 5 of Figure 4, showing the split part oi.' the housing which is removed.

With reference to the drawings, the switch is designated generally by the reference character I2 and is arranged to be operated by an actuating electro-magnet indicated by the reference character I3.

The switch I2 and the actuating electro-magnet I3 may be mounted on a base II therein to facilitate the anchoring of the entire assembly to a suitable support, The actuating electro-magnet I3may be of any suitable design orV construction and is arranged to be ciectrically energized by the conductors 5ft, and acts to close the switch I2 when energized, in a man ner to be described. The actuating electro-magnet I3 has an operating member @fl extending upn wardly from one side thereof. As illustrated, the operating member 4'! is in its lower or retracted position. The downward travel of the member ci opens the contacts and is arrested by means of the adjustable nuts It.

In the drawings, the switch i2 is arranged to interrupt a three phase circuit by three sets of contacts designated, respectively, as A., B and C disposed in a split insulating housing. The set of contacts A, B and C for the respective phases of the electric circuit are of the same construction and correspondingl parts bear the same reiu erence character. As shown, each set of contacts is arranged to produce a double-break and comprises two stationary contact means I8 and It! and two movable contact means 2U and 2 I. The contact means I8 and 20 comprise one pair o1' contacts and the contact means I9 and 2| I0 having holes pair of contacts consisting -means IB and comprise a recess v upper end of the recess comprise another pair of contacts'. The pair of contacts consisting of the contact means I9 and 2l are disposed closer to of the contact means i3 and 20. The movable contact means 20 and 2l are connected together by a bridge member 53. As illustrated best in Figure 2, the bridge memthe base It than the bers 53 for the respective phases A, B and C are arranged to be simultaneously'actuatedby a motion transmitting means i3 which isl actuated by the member I1 of the actuating electro-magnet i3.

Each of thefpair of contacts is arranged to be interrupted in a split insulating housing comprising two partsv 22 and 23. The part 22 comprises an insulating `support member and the part 23 comprises an insulating body member adapted to be detachably connected to thelinsulating support member by screws i5 which extend through holes 51 in the insulating body member 23. The insulating support member and the insulating body member have mating wall surfaces it and I1, respectively, abutting against each other and forming the, split between the members. The split insulating housing has individual arc chambers for each of the pair of separable contacts. The arcs chambers are designated by the reference characters 2d and 25. The arc chambers 2d respectively enclose the stationary contact 4I and the arc the bridge member 53 chambers 25 respectively enclose the stationary Y contact meansi and comprise a recess B2. The

portion 43 which is part of the mating split wall I6 or the insulating supporting housing 22. Similarly, the upper end of the recess 42 for the stationary contact means I9 is closed by a wall portion 4e which'also comprises a part of the mating splitwall IB of the insulating supporting housing' 22. The lower end of the recess 4I is'provided 4i is closed by a wall` with an opening 39 in which the movable contact means 20 is operated by the motion transmitting means I4. The Alowermost 'end is provided with an opening 40 in which vthe movable' contact means 2l is operated by the motion transmitting means I4. The stationary contact means I8 and I9 are of the same construction and comprise a post 2E having a terminal extension 21 provided on the upper end e thereof and having a replaceable contact element 32 removably mounted on the lower end thereof. The terminal extensions 21 extendthrough openings` in' the insulating support member 22 4and are securely fastenedto the insulating support member 22 by terminal nuts 28. A shoulder 29 which is provided between `the post 26 and the terminal extension 21 rests against a washer 3 0 which is embedded in the insulating support member 22. The lower end of the post 261s provided with a reduced threaded portion 3| and. is arranged to threadably engage a replaceable contact element 32. The underneath side of the replaceable contact element 32 may be provided of the recess 42 anchored to the base I0 by means of screws I5 and the actuating electro-magnet I3 may be anchored to the base I0 by screws 36. The movable contact means and the motion transmitting means I6 in their operative position are disposed in the said gap `and obstruct thewithdrawalof the insulating body member 23, so that the removable insulating body member 23 cannot be is in its operative their upper ends provided with inturned anges 5e which constitute stops for holding the bridging member 53 within the spring cagei under the compression of the spring 52. Each side edge of the bridging member 53 is provided' with a notch presenting shoulders 55 for engaging the side edges of thespringcage 5i. The shoulders 55 prevent a lateral movement of the bridging member 53- within the spring cage 5I. As the movable contact means engage the stationary contact means, the spring 52 is compressed and thereby assures that all of the pairs of contacts are making a. Aresilient pressure engagement. Each of the bridging members 53 and the movable contacts carried thereby may be readily removed from the spring cage 5I by manually depressing the spring 52 and then turning thev bridge member 53 until at least one of the notches on the side edge of the bridging member 53 clearsA the inwardly turned flange 54, after which the bridging member may be removed from the spring position. In other words,-I am able to remove and inspect the movable contacts without removl ing the housing.

In operation, all of the movable contact means are operated substantially simultaneously by upward movement of the motion transmitting means with a contact tip member 33 which is arranged y means and the end 56 of the operating member 41 to provide a space for the removal of the removable insulating body member 23. The stationary insulating support member 22 may be element l31 ofthe movable -from the` stationary contact I4 for closingI the three phases of the electrical circuit. Upon the interruption of the movable contact means by a downward movement, a double brea occurs between the line cgnductors 34 i and 35 of each of the phases A, Band C. The interruption occurs upon de-energizing the ace tuating electro-magnet I3, and is made to occur quickly by sudden expansion of the'compressed springs 52 reacting upon the motion transmitting means `I4 and giving it a quick kick downwardly. As the movable contact means for each pair of contacts is separated from the stationary contact means, the arc between the separable contacts is in the recessed arc chamber which houses the pair of contact means. As the movable contact meansfor the pair -is quickly withdrawn means, if the arc between the contact means is not immediately ruptured, it tends to follow the movable contact means into the opening through which the movable contact means operates. The movement of motion transmitting means vable contact means operates.

dropped downwardly v lating body member 23 the movable contact means is arrested when the adjustable nuts 49 engage the electro-magnet I3. In my invention, I preferably provide for arresting the movement of the movable contact means in the openings through which the mov- These openings constitute guides for the'movable contact means, which t in the openings with therebetween, and the small chambers above the movable contact means when in their downward arrested position, are therefore substantially closed chambers. As shown inthe drawings, the post 26 in the recess 24 projects from the end wall portion 43 thereof into said recess to a point therein, whereby the contacts separate in a region which is closer to the opposite end wall of the recess containing the small chamber or opening 39 than to the end wall portion 43 constituting the top closure 'end for the annular recess. Similarly, thepost 26 in the recess 25 projects from the end wall portion 44 thereof into said recess to a point therein whereby the contacts separate in a, region which is closer to the 'opposite end wall of the recess containing the small chamber or opening 40 than to the end wall portion 44 constituting the upper closure end for the tannular recess. Inasmuch as the contacts. separate in a region relatively close to the small chambers or openings, the actuating means may quickly withdraw the movable contacts thereinto, whereby the arc is readily extinguished. The motion transmitting means i4 holds the movable contact means relatively stable so that the movable contact means maybe adjusted bythe adjustable nuts 49 to be further withdrawn from the said openings. In order that the movable contact means may restrict the openings in which they operate when the contact means are fully withdrawn, so that the small chamber will be formed, the area between the movable contact means and the said openings should be smaller than the area of the opening. In other words, the movement of the movable contact means is arrested prior to a point where the area between the movable contact means and the said opening equals the area oi the opening. Y

In removing the insulating body member 23, it is rst necessary that the motion transmitting means id and the .movable contact means be removed from the gap between the end 56 of the member 4'! and the contact tip members 33 of the stationary contact means. of operation, the removable insulating body member 23 cannot be removed in thev normal operative position of the motion transmitting means. However, the motion transmitting means may be readily removed by detaching the movable cross arm 4S from the member 41 by taking out the screws 48. When the motion transmitting means i4 and the movable contact means carried thereby are removed then the removable insulating body member 23 may be withdrawn or into the gap between the end 56 of the member 4l and the contacttip members 33, as shown in Figure 4. The insulatmay then be removed laterally, whereupon the stationary contact means are readily accessible for inspection andreplacement. Instead of using the screws 48, a suitable hinge construction may interconnect the member 4l and the movable cross arm 46, whereby the motion transmitting means I4 and the movable contact means may be removed from the gap by merely operating the hinge construction.

Ingmy invention, the springs 52 are disposed a small clearance To insure safety I externally of the insulating housing so that they are free from the iniluence of the arc in the arc chambers. In other words, the springs 52 are free from heat or other damaging influences, or burning, which would otherwise occur if they were mounted within the arc chambers or otherwise exposed to the are in the arc chambers.

Although I have described my invention with a certain degree of parti'cularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope oi' the invention as hereinafter claimed.

What is claimed is:

1. In combination, a quick-acting circuit interrupting switch having at least a iirst and ay second pair of separable contacts, each of said'4 pair including a stationary a movable contact means, a

contact means and base, a split insulathaving at least a first arc pair of contacts and a second arc chamber for the second pair of contacts, mounted on the base for quickly operating the movable contact means to effect a quick circuit interrupting movement, said split housing comprising an insulating support member and a readily removable insulating body member adapted to be detachably connected to the insulating support member, said insulating body member having at least a first recess constituting a portion oi the first arc chamber and a second recess constituting' a portion of the second arc chamber, said insulating body member also having iirst and second openings connecting the ilrst and second recesses respectively to the outside of the split "housing, said movable contact means for the first and second pair of contacts being movable respectively in said openings upon the actuation thereof by the actuating means, said insulating members having mating Wan surfaces abutting against each other and .forming the split between the said members, wall surfaces extending transversely of the said recesses, said stationary -contact means for each pair having a irst end portion mounted to the said contact element and said movable contact means for each pair having abutting contact surfaces between which current is interrupted, the stationary contact means for said first pair of contacts being disposed closer to said base than the stationary contact means for said second pair of contacts, said second end portion for each stationary contact means projecting from said insulating support member into said recess respectively and extending beyond said split, whereby said second end portions and the contact elements provided thereon for said 'pairs of stationary contact means are readily accessible upon removal of the insulating body member, and stop means to prevent the said movable contact means from being withdrawn from said openings in the insulated body member during the circuit interrupting movement.

2. In combination, a switch having stationary contact means and movable contact means, a split housing having a iirst and a second chamber for the contact means, said second chamber being smaller than the rst chamber and comprising an opening extending from the first chamber to the outside of the housing, said split actuating mechanism said mating aerien housing comprising an insulating support member and. a readily 'removable insulating body member having an annular internal wall con stituting a portion of the first chamber, an elongated element mounted on the insulated sup port member and having a projection portion ex- 4tending into said iirst chamber toward the second chamber, said projection portion supporting the stationary contact means upon the end thereof, said internal annular wail of the nrst chamber and the external surface of the sta= `tionary contact means and-the projection portion of the saidelongated element denning an annularA recess extending from the stationary contact means toward the insulating support member and away from'the second chamber, actuating means for initially 'separating the movelongated element mounted on the said 'rst end able contact means from the stationary contact means in the first chamber, said actuating means quickly withdrawing the movable contact means into said second chamber, means for arresting the movement of the movable contact means in the second chamber, whereby an arc drawn between the contact means is conned substantially in said chambers, said insulating members having mating wall surfaces abutting against each other and forming the split -between. said members, said mating wall surfaces extending transversely of said iirst chamber, said projection portion ot said elongated element-projecting trom said insulating support member into said nrst chamber and extending beyond said split, whereby said stationary contact means is readily accessible upon removalof the insulating body member-'trom the insulating support member.

3. in combination, a switch having stationary contact means and movable contact means, a housing-having a nrst and a second chamber wall portion and having a projection portion extending into said liirst chamber toward the second chamber, said projection portion supporting the stationary contact means upon the end thereof, said internal 'annular wall portion of the rst chamber and the external. surface of the stationary contact means and the projection portion v of the said elongated element defining an elon= gated annular recess extending from the stationary contact means toward the nrst end wall portion and away from the second chamber, actuating means for initially-separating the movable contact means from the stationary contact means in the rst chamber, said actuating means quickly withdrawing the movable contact means into said second chamber, and means for arresting the'movement of the movable contact means v in the second chamber, whereby an arc drawn between the contact means is conned substan tially in said chambers, 'said projection vportion of the elongated element projecting from the said rst end wall portion into said rst cham- .loer to the point thereinwhereby the contact means separate in a region which is closer to said second end wall portion containing the second chamber than tothe rst' end wall portion constituting an endfor the said annular recess.

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