US2866031A

US2866031A - Circuit breaker

Info

Publication number: US2866031A
Application number: US628426A
Authority: US
Inventors: Jr Joseph D Findley
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1956-12-14
Filing date: 1956-12-14
Publication date: 1958-12-23
Anticipated expiration: 1975-12-23

Description

Dec. 23, 1958 Filed Dec. 14, 1956 WITNESSES a A w J. D. FINDLEY, JR

CIRCUIT BREAKER -Fig.l.

3 Sheets-Sheet 1 INVENTOR Joseph D. Find|ey,dr.

ATTORNEY Dec. 23, 1958 J D. FlNDLEY, JR 2,866,031

' CIRCUIT BREAKER Filed Dec. 14, 1956 3 Sheets-Sheet 2 Dec. 23, 1958 J, FINDLEY, JR 2,866,031

CIRCUIT BREAKER Filed Dec. 14, 1956 s Sheets-Sheet :5

Fig.4.

United States Patent O F CIRCUIT BREAKER Joseph D. Findley, Jr., Forest Hills, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December '14, 1956, Serial No. 628,426

7 Claims. (Cl. 200106) This invention relates to circuit breakers, and more particularly to tripping mechanisms for automatically starts the closing movement of the armature and the operating mechanism, creates a shock of sufiicient magnitude to start the light-load latch in tripping direction. Also, the sudden stopping of the armature and the operating mechanism when they reach the closed position creates a very heavy shock to the framework and mechanism of the breaker which, at times, results in'moving the lightload latch mechanism to unlatching position causing false opening of the breaker.

It is an object of the invention to provide a circuit breaker embodying an improved tripping mechanism that does not trip the breaker in response to shocks or jarring forces.

Another object of the invention is to provide a'circuit breaker embodying an improved tripping mechanism in which the parts are'disposed and arranged to'resist tripping action in response to shocks.

Another object of the invention is to provide a circuit breaker including a solenoid for closing the breaker and embodying an improved tripping mechanism in which the parts of the tripping mechanism are supported relative to the direction of the shock of the closing solenoid so that the shock of the closing solenoid does not cause tripping movement of the parts.

Another object of the invention is to provide a circuit breaker embodying an improved tripping mechanism which prevents tripping movement in response to shocks and which does not employ inertia members for blocking tripping movement of the parts of the tripping mechanism.

Other objects and advantages of the invention will be pointed out in the following description and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In said drawings:

Figure 1 is an elevational view, partly in section, of a circuit breaker embodying the principles of the invention.

Fig. 2 is a detail view of the operating mechanism showing said mechanism in the closed position.

Fig. 3 is a view similar to Fig. 2 but showing the mechanism in the tripped open position.

Fig. 4 is a view similar to Figs. 2 and 3 but showing the mechanism in the reset and relatched position.

Fig. 5 is a top plan view of the tripping mechanism; and

ice

2 Fig. 6 is a front elevational view of the 'tripping' tn'echanism shown in Fig. 5.

Referring to Fig. 1 of the'drawings, the circuit breaker is of the roll-out type and is mounted on a truck comprising a pair of side plates 11 (only one being shown) which are rigidly joined by

cross members

13, 15, 17 and 19 to form a rigid frame for supporting the circuit breaker. The truck is mounted on wheels 20 to facilitate rolling the breaker into and out'of a cubicle in orderto connect the breaker in an electrical circuit and to disconnect it therefrom.

The circuit breaker is of the multipole type (only'one pole being shown) and comprises generally 'a plurality of sets of separable contact means 21, a common'operating mechanism 23, a trip device 25 and a closing means 27.

The contact means consists generally of

stationary contact blocks

29 and 31 mounted respec'tively'on upper and

lower terminals

33 and 35 which, in turn, are "rigidly supported on a back plate 37 rigidly supported on the truck.

The specific contact means is fully disclosed in Patent No. 2,717,292, issued September 6, 1955, to Russell Frisch and Paul Olson and assigned 'to the assignee of the instant invention, for which'reason only a brief description thereof is given.

A switch arm 41 is provided for operating the movable contact and is pivotally mounted on apivotvpin 43 who lower terminal-member 35. The switch arm '41 is operatively connected by means of an insulating operating rod 45 to the operating mechanism 23. The upperend of the operating rod 45 is pivotally connected'by a.pin 47 to the switch arm 41, and the lower'endof the operating rod is threaded and is connected by suitable-means such as the nuts 49 to an angular cross bar SI-which is common to all of the poles of the breaker. The crossbar=51 is pivotally connected at its ends bypivot pins53-(only one being shown) to an operating bellcrank lever55 (Figs. 1, 2, 3 and 4) which is pivotally mounted ona shaft 57 supported in the sidemembers59 of-a generally U-shaped frame 61. The frame 61 is rigidly supported on the cross members 13 and 17 by meansof a plate-62 and is shown partly broken away more clearly to show the operating mechanism.

In addition to the operating lever 55, the operating mechanism consists of a closing lever'63 pivotally mounted on a shaft 65 supported in the side members 59 of the frame 61. The closing lever 63 is connected by means ,of a link 67 to the moving armature 69 of a closingsolenoid 27. The link 67 is pivotally connected by'a-pin 70 to the armature 69. The operating lever 35 and the closing lever 63 are connected by means of an underset thrusttransmitting toggle comprising toggle links 73 and '75 pivotally connected together by a knee pivot pin 77. The toggle link 73 is pivotally connected to one arm ofethe operating bell crank 55 by a pin 79, and the togglelink 75 is pivotally connected to the closing lever 63 by a pin 81 which also pivotally connects the link 67 totheclosing lever. The closing lever 63 is held in the closed position (Fig. 2) by a spring-biased latch 83, which normally engages a roller 85 on the pin 81.

The toggle 7375 is releasably held in-a slightlyiunderset position by a latch member '87 mounted on the shaft 65 for movement relative thereto, A link 89 CQH? nects the knee of the toggle 7375 to the latch member 87, being pivotally connected to the latter by a pin 91, The latch member 87 is normally releasably held in latching position by a latch 99 forming part of the latch? ing and tripping mechanism 25 as seen in Fig. 2. The latch member 87 carries a latch roller 93 rotatably mounted on a pin 95 (Fig. 5) in the latch member. The latch roller 93 normally engages the inner end'97-of-the balanced main latch 99 pivotally mounted for horizontal movement by pivot means 101 supported on a cross bar 103 which in turn is attached to the cross member 13 by means of bolts 105, and in a bracket 107 secured to the under side of the cross bar 103.

The electromagnetic trip device 25 (Figs. Sand 6) is supported on a front plate 109 which is secured by means of bolts 111 to the cross bar 103 and to the cross member 15. The trip device 25 comprises a fixed magnet yoke 113 rigidly mounted by means of bolts 115 and spacers 117 on an angle bracket 119 which is secured by means of screws 121 to the front plate 109. A movable armature 123 is rigidly secured to the lower end of a U-shaped armature lever 125 (Figs. 4 and 6), the spaced side members of which are pivotally mounted on a pin 127 which is supported by the front plate 109 and in a bracket 129 secured by means of screws 131 to the front plate. A member 133 secured to the upper end of the lever 125 carries anadjusting screw 135 which is adapted upon operation of the electromagnet, to engage the outer end 100 of the latch 99 and actuate the latch. The main latch 99 is biased by means of a spring 137 against an adjustable stop 139 supported in a bracket 141 secured by screws 143 to the front plate 109. A spring 145 tensioned between the armature lever 125 and the bracket 141 biases the armature against a stop 147 which is also supported on the bracket 141.

When an overload current occurs, the tripping electromagnet is energized and operates the latch 99 causing it to release the latch member 87. Upon release of the latch member 87, the toggle 7375 immediately collapses to the position shown in Fig. 3 permitting clockwise rotation of the operating lever 55 and opening movement of the switch arms 41 for the several poles of the breaker.

Collapse of the toggle 73-75 causes counterclockwise rotation of the toggle link 75 about the pin 81 during which movement a projection 149 on the lower end of the toggle link 75 engages and moves the latch 83 to its unlatching position. As soon as the latch 83 is disengaged from the roller 85, a spring 151 connected under tension between the armature 69 and the cross bar 103 moves the armature toward the left to its unattracted position (Fig. 4) where it is arrested by the end of the link 67 engaging an adjustable stop 153 on the cross member 15. This movement straightens the toggle 73- 75 and through the link 89 restores the latch member 87 to its latching position as shown in Fig. 4. The circuit breaker is now in condition to be closed by operation of the closing solenoid 27.

Referring particularly to Fig. 1, the closing solenoid 27 comprises, in addition to the armature 69, a fixed core member 155 rigidly mounted on an end plate 157 which is supported on the cross member 19 and attached by means of bolts 159 to the frame 61. An energizing coil 161 is mounted on an insulating spool 163 and surrounds the armature 69 and the fixed core 155.

With the parts of the operating mechanism in the position in which they are shown in Fig. 4, energization of the closing solenoid 27 attracts the armature 69 which, through the link 67, moves the closing lever 63 counterclockwise about its pivot 65. Since the latch member 87 is now held by the latch 99, the link 89 holds the toggle 7375 in thrust-transmitting condition causing it to transmit the closing force of the armature to the operating lever 55. This thrusts the operating rod 45 upward and moves the switch arm 41 to the closed contact position. At the end of the closing stroke the latch 83 reengages the roller 85 and holds the mechanism in the closed position.

The shock of the closing solenoid 27, both in starting the closing operation and the shock at the end of the closing operation, are delivered in the direction of the axis of the closing solenoid, that is; from front to rear of the breaker and vice versa. The balanced latch 99 is mounted on the vertical pivot 101 and is disposed lengthwise in the direction in which the shock generated by the solenoid is transmitted. Consequently, such shocks do not tend to move the latch 99 in tripping direction. The stop 139 for the latch 99 is disposed transversely of the direction of the shock and also does not transmit a shock force to the latch to start it in tripping direction. The armature 123 is prevented from transmitting a force to the latch 99 in response to the closing shock by disposing the armature pivot 127 axially in the direction of the shock. The armature stop 147 is disposed transversely of the direction of shock, and hence, transmits none of the closing shock to the armature.

Having described the invention in accordance with the provisions of the patent statutes, it is to be understood that various changes and modifications may be made in the particular. embodiment disclosed without departing from the spirit of the invention.

I claim as my invention:

1. A circuit breaker comprising power-operated means for closing the breaker, said power-operated means causing shocks at the beginning and end of a closing operation, said shocks being transmitted in a predetermined direction, tripping means comprising a balanced latch operable to effect automatic opening of the breaker, said latch having its length disposed in the direction of said shock so as to prevent tripping movement of said latch in response to said shocks, and a pivoted armature operable to actuate said latch, said pivoted armature having its axis disposed in the direction of said shocks to prevent transmitting said shocks to said armature in a direction to cause tripping movement of said armature.

2. A circuit breaker comprising power-operated means for closing the breaker, said power-operated means causing shocks at the beginning and end of a closing operation, said shocks being transmitted in a predetermined direction, tripping means comprising a balanced latch pivoted intermediate its ends and operable to effect automatic opening of the breaker, stop means engageable by said latch and disposed transversely of the direction of the shock to thereby prevent transmission of said shock to said latch, and a pivoted armature operable to ac tuate said latch, said pivoted armature having its axis disposed in the direction of said shocks to prevent transmitting said shocks to said armature in a direction to cause tripping movement of said armature.

3. A circuit breaker comprising power-operated means for closing the breaker, said power-operated means generating shocks during a closing operation, said shocks being transmitted in a predetermined direction, tripping means comprising a balanced latch operable to efiect automatic opening of the breaker, said latch being pivotally supported and having its length disposed in the direction of the shock so as to prevent tripping movement of said latch in response to said shocks, an electromagnet including an armature movable to operate said latch, and stop means for said armature disposed transversely of the direction of the shock to thereby prevent tripping movement of said armature in response to said shocks.

4. A circuit breaker comprising power-operated means for closing the breaker, said power-operated means generating shocks at the beginning and end of a closing operation, said shocks being transmitted in a predetermined direction, tripping means comprising a balanced latch pivoted intermediate its ends and operable to efiect automatic opening of the breaker, stop means engaged by said latch and disposed transversely of the direction of the shocks to therebyprevent transmission of said shocks to said latch, an armature movable to operate said latch, and stop means for said armature disposed transversely of the direction of the shock to thereby prevent tripping movement of said armature in response to said shocks.

5. A circuit breaker comprising relatively movable contact means and power-operated means for closing said contact means, said power-operated means causing shocks at the beginning and end of a closing operation, said shocks being transmitted in a predetermined direction, tripping means comprising a balanced latch operable to effect opening of the breaker, electromagnetic means including an armature operable to actuate said latch, pivot means pivotally supporting said armature, said pivot means having its axis disposed in the direction of said shocks to prevent transmission of said shocks to said armature in a direction to cause tripping movement of said armature.

6. A circuit breaker comprising relatively movable contact means and power-operated means for closing said contact means, said power-operated means causing shocks at the beginning and end of a closing operation, said shocks being transmitted in a predetermined direction, tripping means comprising a latch operable to elTect opening of the breaker, electromagnetic means including an armature operable to actuate said latch, pivot means pivotally supporting said armature, said pivot means having its axis disposed in the direction of said shocks to prevent transmission of said shocks to said armature in a direction to cause tripping movement of said armature, and a stop for said armature disposed transversely of the direction of said shocks to thereby prevent transmission of said shocks to said armature in a direction to cause tripping movement of said armature.

7. A circuit breaker comprising power-operated means for closing said breaker, said power-operated means generating shocks during closing operation, said shocks being transmitted in a predetermined direction, a balanced latch pivoted intermediate its ends and operable to effect automatic opening of said breaker, latch stop means against which said latch is biased, said stop means being disposed transversely of the direction of said shocks to prevent transmission of said shocks to said latch, an armature operable to actuate said latch, pivot means pivotally supporting said armature, said pivot means having its axis disposed in the direction of said shocks to prevent transmission of said shocks in a direction to cause tripping movement of said armature, and an armature stop against which said armature is biased, said armature stop being disposed transversely of the direction of the shocks to thereby prevent transmission of said shocks to said armature in a direction to cause tripping movement of said armature.

References Cited in the file of this patent UNITED STATES PATENTS 2,427,998 Wilckens Sept. 23, 1947 2,575,709 Grissinger et al. Nov. 24, 1951 2,725,442 Tremblay et al. Nov. 29, 1955