US2760028A

US2760028A - Circuit breakers

Info

Publication number: US2760028A
Application number: US377179A
Authority: US
Inventors: Eugene J Walker
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1953-08-28
Filing date: 1953-08-28
Publication date: 1956-08-21
Anticipated expiration: 1973-08-21

Description

A g- 1, 1956 E. J. WALKER CIRCUIT BREAKERS 2 SheetsSheet 1 Filed Aug. 28, 1953 INVENTOR Eugene J. Walker. 01 B a) W 'ATTORNE E. J. WALKER CIRCUIT BREAKERS Aug. 21, 1956 2 Sheeis-Sheet 2 Filed Aug. 28, 1953 INVENTOR, Eugene J. Walker. & BYX' W ATTORNEY WITNESSES wwd United States Patent CIRCUIT BREAKERS Eugene J. Walker, Beaver, Pa assiguor to Westinghouse Electric Corporation, EastPittsburgh, Pa, 2; corporation of Pennsylvania Application August 28, 1953, Serial No. 377,179

9 Claims. (Cl. 200-116) This invention relates to circuit breakers and more particularly to circuit breakers which are manually operated to open and close the circuit and which are automatically operated to open the circuit in response to overload currents.

An object of the invention is to provide a circuit breaker which is manually operated to open and to close the circuit and is automatically operated toopen the circuit, with indicating means for giving an indication that the breaker has been automatically opened.

Another object of the invention is to provide a circuit breaker embodying switch means operated only in response to automatic opening of the breaker to effect an indication of the condition of the breaker.

Another object of the invention is to provide a circuit breaker with a signalling switch that is disposed entirely within the breaker housing.

Another object of the invention is to provide a circuit breaker with means of simple construction and reliable in operation for signalling when the circuit breaker. has been automatically tripped open.

A further object of the invention is to operate a signal switch on a circuit breaker by its own relative light spring early in the movement of the breaker trip member, and to avoid subjecting the signal switch to the force of the relative heavy tripping spring or to the stored energy in the rapidly moving trip member at the end of its stroke. i

The invention, both as to structure and operation, together with additional objects and advantages thereof will be best understood from the following detailed description thereof when read in conjunction with the accompanying drawings.

In said drawings:

Figure l is a vertical sectional view of a circuit breaker embodying the principles of the invention;

Fig. 2 is an enlarged fragmentary view. of a portion of the breaker showing the signal switch mounted in the circuit breaker housing;

Fig. 3 is a vertical sectional view taken along line IIIIII of Fig. 2 and looking in the direction indicated by the arrows; and i v I Fig. 4 is a perspective view showing the signal switch, the trip device and the member releasable to effect automatic opening of the breaker and for effecting operation of the signal switch. I v 7 Referring to Fig. 1 of the drawings, the circuit breaker illustrated comprises, generally a recessed base 11 of molded insulating material, a cooperating cover 13. also of molded insulating material, a stationary contact 15, a pivoted switch member 17 carrying a movable contact 19 for cooperating with the stationary contact, operating means indicated generally at 21, a trip device indicated generally at 23 and a signal switch indicated generally at 24.

The stationary contact 15 is rigidly mounted on the inner end of a conductor 25 which extends out through flce an opening in the base 11 and has a connecting means 27 on its outer end.

The Operating mechanism 21 and the pivoted switch 17 are supported in a main frame 29 comprising spaced frame members, only one of which is shown, suitably secured to the base 11. The switch member 17, which carries the movable contact 19 at one end, comprises a resilient strip secured at its other end to a support member 31 pivotally mounted on a pin 33 supported in the frame members 29.

The operating mechanism 21 for the circuit breaker comprises a toggle consisting of a pair of toggle links 35 and 37, a pivoted carrier or trip member 39;, an overcenter spring 41 and a U shaped operating lever 43. The toggle links 35 and 37 are pivotally connected together by a knee pivot pin 45 and the toggle link 35 is pivotally connected to the carrier 39 by a pivot pin 47. The toggle link 37 is pivotally connected to the switch arm support member 31 by means of a pivot pin 49,. The .overcenter spring 41 is connected at its lower end to the knee pivot pin 45 of the toggle 3537 and at its outer end to the yoke portion of the .Ll-shaped operating lever 43. The legs of the operating lever 43 are pivoted on projections 51 (only one being shown) formed outwardly from the main frame members 29. Ears 53 also formed outwardly from the main frame members 29 serve to limit the movement of the operating lever 43. An operating handle 55 of molded insulating material is mounted on the outer end of the operating lever 43 and projects out through an opening 57 in the cover 13. An arcuate portion 59 of the handle serves to substantially close the opening 57 in all positions of the operating lever 4-3. The trip member or carrier 39 is pivotally mounted on a pin 61 supported in the main frame 29 and is normally releasably restrained in operative position by the trip device 23.

The circuit breaker is opened and closed manually by manipulation of the operating handle 55. In order to, open the breaker, the handle 55 and the operating lever 43 are moved counterclockwise from the position shown in Fig. 1. This movement carries the line of action of the vercenter spring 41 over to the left of the pivot pin 47 thereby causing collapse of the toggle 3537 and opening movement of the switch member 17- to, open the contacts with a snap action. Clockwise movement of the handle 55 and the operating lever 43. back to the position shown in Fig. 1 moves the line of action of the overcente r spring 41 over to the right of the pivot 47 thereby straightening the toggle 3537 which moves the switch member 17 to its closed position with a snap action.

7 The trip. device 23 comprises a bimetal element 6 3 having an armature 65 rigidly mounted thereon and a xed magnetic member 67. The bimetal element 63 and the fixed magnetic member 67 have mounting feet formed thereon and both are rigidly secured to the base 11 by a screw 69. The mounted end of the bimetal element 63 is connected by means of a flexible conductor. 7-1 to the switch member 17 and the free end of the bimetal element is connected by means of a flexible conductor 73 to a conductorv '75 which extends out through an opening in the end wall of the base 11 and has a terminal connector 77 mounted on its outer end. adjusting screw '79 threaded into the upper or free end of the bimetal element 63 has a latch portion 31 which is engaged by a latch member 83 on the trip member 39 in order to releasably restrain this member in operative position.

The circuit breaker is tripped open automatically in response to overload currents by the trip device just described. The bimetal element 63 is heated by overload currents below a predetermined value of, for example, times normal rated current and, when heated a predetermined amount, bends toward the left releasing the releasable member 39. The trip member, when released, rotates clockwise about its pivot 61 under the influence of the overcenter spring 41 carrying the pivot pin 47 over to the right of the line of action of the overcenter spring. This causes collapse of the toggle 3537 and opening movement of the switch member 17.

Following an automatic opening operation, it is necessary to reset and relatch the releasable member 39 before the contacts can be closed. The carrier 39 is reset and relatched by movement of the handle 55 to the off position. During this movement of the handle, a projection 85 on the operating lever 43 engages and moves the carrier 39 counterclockwise about its pivot 61 causing the latch member 83 to wipe by the latch 81 slightly flexing the bimetal element 63 which thereafter springs back to its normal position with the latch 81 in latching engagement with the latch member 83 on the carrier. The circuit breaker is then closed in the previously described manner by clockwise movement of the handle 55 to the on position.

Upon the occurrence of an overload current of ten times or more of normal rated current, as a short circuit current, the electroresponsive means 65-67 is energized sufficiently by the current flowing through the bimetal element 63 to move the armature 65 toward the fixed magnetic member 67 thus bending the bimetal element and causing instantaneous release of the trip member 39 and opening of the breaker.

Means is provided for etfecting a signal when the circuit breaker is automatically tripped open. The signalling means comprises the switch indicated generally at 24 and is operated to give a signal only when the breaker is automatically tripped open. it is not operated when the breaker is opened manually. The signal switch 24 comprises a pair of spaced stationary contacts 87 mounted in the horizontal portion of a mounting bracket 89. The bracket 39 is composed of insulating material and is rigidly mounted on the side wall of the cover 13 by means of bolts 91 and nuts 93 as best seen in Fig. 3 of the drawing. A bridging contact 95 is rigidly mounted on the lower end of a plunger 96 slidably mounted in an opening in the bracket 89. The bridging contact 95 is adapted to cooperate with the spaced stationary contacts 87 to control a circuit over Wires 97 (Figs. 2, 3 and 4) for energizing a suitable visual or audible signal. The wires 97 are secured to the cover 13 by a clamp 98. The wires 97 are attached to terminals 99 which are secured to the bracket 89 and electrically connected to the contacts 87 by means of rivets 101 which secure the contacts 87 to the bracket. The plunger 96 is encased in an insulating sleeve 103 which terminates at its upper end in an insulating button 105. A relatively light spring 107 compressed between the insulating button 195 and an insulating washer 109 biases the plunger 96 upwardly to engage the bridging contact 95 with the stationary contacts 87, but the plunger is normally restrained in its open contact position, as shown, by engagement of the latch end of the carrier or trip member 39 with the insulating button 105. The switch is insulated from the breaker operating mechanism by means of an insulating barrier 111 mounted on the main frame 29.

When the circuit breaker is tripped open by operation of the trip device 23 (Figs. 1 and 4) the carrier 39 is released and rotated clockwise about its pivot 61 (Fig. 1) to efiect opening of the contacts. The early part of the movement of the latch end of the trip member releases the plunger 96 permitting the spring 107 to move the plunger upwardly to engage the bridging contact 95 with the stationary contacts 37. This closes the circuit and energizes the signalling device (not shown) which will remain energized as long as the breaker is in the tripped open position. When the carrier 39 is moved to reset and relatch the mechanism, as previously described, the carrier engages the button and opens the signal switch 24.

The carrier 39 is not released when the breaker is manually operated to the open position, consequently, the switch 24 will be maintained in the open position, and the signalling device will not be energized on manual opening operations.

An important feature of the invention is that the auxiliary switch 24 is mounted solely on the cover 13 of the breaker. From a manufacturing standpoint this is important since it requires no alteration of the breaker mechanism or of the base, it being necessary only to mount on the base 11 which supports the breaker mechanism, a cover 13 having the auxiliary signalling switch unit 24 thereon.

Another important feature of the invention is that the switch unit 24 is mounted entirely inside the breaker housing so that the circuit breaker can be mounted in the limited space provided in a panelboard or load center.

The switch is spring operated to the closed position to effect a signal upon automatic release of the breaker and, hence, is not subject to the shock of automatic opening of the breaker under action of the relatively heavy main spring, nor to hammering by the trip member at the end of its travel. The signal switch is of simple construction having few parts, is reliable in operation and inexpensive to manufacture.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes and modifications may be made in the structural details and combination of elements disclosed without departing from some of the essential features of the invention.

I claim as my invention:

1. A circuit breaker comprising a two part housing, a releasable operating mechanism mounted in one part of said housing, said operating mechanism being releasable to effect automatic opening of said breaker, an auxiliary switch mounted inside said housing on the other part of said housing, spring means biasing said auxiliary switch to one position, means on said releasable operating mechanism normally engaging and positively restraining said auxiliary switch in another position, and said spring upon release of said operating mechanism moving said auxiliary switch to said one position.

2. A circuit breaker comprising a two part housing, operating means including a member releasable to effect automatic opening of said breaker, said operating means being mounted on one of said housing parts, an auxiliary switch mounted inside said housing on the other of said housing parts, said releasable member in the closed position of said breaker engaging and positively restraining said auxiliary switch in one position, trip means responsive to overload currents for releasing said releasable member, and spring means operative upon release of said releasable member for moving said auxiliary switch to another position.

3. In a circuit breaker comprising an enclosing housing including a base and a cover, a releasable member movable when released to effect automatic opening of said breaker, trip means including a latch engaging and releasably restraining said releasable member, said trip device being operable to actuate said latch and release said releasable member, all mounted on said base, an auxiliary switch device, a support member mounted inside said housing on said cover, said support member having a portion extending into said base for supporting said auxiliary switch device in a position where it is engaged and positively held in one position by said releasable member in the latched position of said releasable member, and resilient means operative early in the movement of said releasable member to effect opening of said breaker to move said auxiliary switch device to another position.

4. In a circuit breaker comprising an enclosing housing including a base and cover of molded insulating material, a releasable member movable when released to a position to eflect automatic opening of said breaker, latch means releasably restraining said releasable member, a trip device responsive to overload currents to operate said latch means and release said releasable member, all being mounted on said base, an auxiliary switch comprising spaced sationary contacts and a cooperating bridging contact, a support member mounted inside said housing on said cover for supporting said auxiliary switch in a position where it is engaged by said releasable member, said releasable member in the latched position normally positively holding said bridging contact disengaged from said spaced stationary contacts, and actuating means operative upon release of said releasable member for engaging said bridging contact with said spaced stationary contacts.

5. In a circuit breaker comprising a movable switch member, operating means including a releasable operating member having one end pivoted, latch means engaging and releasably restraining the other end of said releasable member, means interconnecting said releasable member and said movable switch member whereby said releasable member releasably restrains said movable switch member in closed position, a trip device for actuating said latch means to effect release of said releasable member and automatic opening movement of said switch member, an auxiliary switch biased to one position and mounted in a position where it is engaged and positively held in another position by said latched end of said re leasable member, said releasable member when released moving away from said auxiliary switch to permit said switch to move to said one position.

6. In a circuit breaker, operating means for opening and closing said breaker, comprising a releasable operating member having one end pivoted, a fixedly mounted trip device engaging and releasably restraining the other end of said releasable operating member, said trip device operating in response to overload currents to release said releasable operating member and effect automatic opening of said breaker, an auxiliary switch, mounting means mounting said auxiliary switch adjacent the restrained end of said releasable member, the restrained end of said releasable operating member in the restrained position engaging and holding said auxiliary switch open, and actuating means operative when said trip device releases said releasable operating member to close said auxiliary switch.

7. A circuit breaker comprising, operating means re- 6 leasable to effect automatic opening of the breaker, trip means mounted on a fixed part normally engaging and releasably restraining said operating means, said trip device being operable to release said releasable operating member, means for manually resetting said releasable means, an auxiliary switch engaged and positively held in one position by said restrained releasable operating means in the closed position of said breaker, biasing means biasing said auxiliary switch to another position and operative when said releasable operating means is released to move said auxiliary switch to said other position, and said releasable operating means when reset engaging and positively moving said auxiliary switch to said one position.

8. In a circuit breaker, operating means comprising a releasable operating member movable when released to a position to efiect automatic opening of said breaker, biasing means biasing said releasable operating member to said position, a fixedly mounted trip device normally engaging and restraining said releasable operating member, said trip device being operable to release said releasable operating member, an auxiliary switch, support means supporting said auxiliary switch in a position where it is engaged and positively held in one position by said restrained releasable operating member, and spring means operative early in the opening movement of said releasable operating member upon release thereof to move said auxiliary switch to another position.

9. In a circuit breaker comprising, operating mechanism including a releasable operating member movable when released to cause automatic opening of said breaker, a fixedly mounted trip device normally engaging and restraining said releasable operating member in an operative position and operable to release said releasable operating member, an auxiliary switch mounted in a position where it is engaged and positively held in one position by said releasable operating member in the operative position of said releasable operating member and resilient means operative early in the travel of said releasable operating member upon release thereof to move said auxiliary switch to another position.

References Cited in the file of this patent UNITED STATES PATENTS 656,282 Brubaker et al Aug. 21, 1900 2,416,407 Runke Feb. 25, 1947 2,468,645 Steinmayer Apr. 26, 1949 2,656,439 Gelzheiser et al. Oct. 20, 1953