US2126412A - Circuit breaker - Google Patents

Description

Aug. 9; 1938. R. N. ROWE 2,125,412

CIRCUIT BREAKER Filed Jan. 12, 1937 2 Sheets-Sheet l ENVENTOR BY U.

Aug. 9, 1938. E 2,126,412

C IRCUIT BREAKER Filed Jan. 12, 1937 2 Sheets-Sheet 2 INVENTOR flay/W017i 730100 Patented Aug. 9, 1938 UNITED STATES PATENT OFFICE CIRCUIT BREAKER Raymond N. Rowe, Plainville, Conn, assignor to The Trumbull Electric Manufacturing Company, Plainville, Conn, a corporation oi. Connecticut Application January 12, 1937, Serial No. 120.159

Claims. (Cl. 200-116) is simple in construction and reliable in operation.

Another object is to provide a device which will automatically open the circuit even when the operating handle or finger piece is held in the olosedcircuit position.

Another object is to provide such a device which can be readily reset after automatic trip- Another object is to provide such a device in which the point of automatic opening can be readily adjusted.

Another object is to provide a construction which will require only a single spring to open the circuit with a snap action when actuated manually or automatically and which will close the circuit with a snap action when actuated manually.

The accompanying two sheets of drawings show two forms of the invention.

Fig. 1 is a side view of the preferred form of mechanism embodying my invention, the parts being shown in the normal open circuit or of! position.

Fig. 2 is a similar view showing the parts in the closed circuit or on positiom Fig. 31s a similar view showing the parts in the openacircuit position-resulting from the automatic thermostatic release action.

Fig. 4 is a vertical sectional view on the plane of the line 4-4 of Fig. l.

Fig. 5 is an exploded perspective view showing the principal parts of the mechanism. I

Fig. 6 is a sectional view of a modified form of mechanism embodying the invention enclosed in an lnsulating'housing and showing the parts in the open circuit or 011 position.

Fig. '7 is a side view of the mechanism of Fig. 6 with the parts in the closed circuit or on position.

Fig. 8 is a side view of the same parts in the open circuit position resulting from the automatic thermostatic release.

Fig. 9 is a perspective view of the movable elements of the form shown in Figs. 6, '7 and 8.

Fig. 10 is a perspective view showing the housing and actuating member of a unit embodying my invention.

The mechanism of the circuit breaker of the switch is preferably enclosed within a housing consisting of a base ill and an upper part i0 suitably secured together and having suitable circuit terminals for the connection of conductors.

All of the moving parts are carried by a frame I i which is suitably secured to the base I0. There are three movable elements all supported directly or indirectly by this frame. These consist of the main switch lever or contact member i2, the actu-. ating arm or lever i3 and the kick-off lever it. The bimetallic thermostatic arm i5 is mounted on the supporting base iii. A flexible lead i5 connects the arm i5 and the contact l2. A single spring l6 connects the switch member i2 and the actuating member i3.

Stationary contact I! is located in a position to be engaged by the contact of the switch member i2. The lever i2 is pivoted or hinged in an open notch or bearing iii in the underside of the upper part of the frame ii. The movable end of switch member I! in. the open circuit position 7 rests against an abutment IS in the frame.

The kick-off member I4 is pivoted in lugs 20 which are bent up from one side of the frame. The actuating arm I3 is hinged on pintles 2| which extend from the opposite sides of the kickoff member ll. The base of the frame ii has an abutment or abutments such as 22 against which a heel orheels such as 23 rests in the normal open circuit position of the parts. The upper arm of the frame Ii is provided with stop shoulders 24 and 25 to limit the movement of the actuating arm i3. The spring i6 is connected to cross piece 2'! in the switch member l2 and to a pin 26 car% rled by the actuating arm iii. The kick-off lever H has a finger 28 which is adapted to engage a part 28 of the switch member l2 when the ther-] mostatlc member i5 releases the kick-off lever I4 The kick-off lever is provided with an adjustable projection 30 which is in the form of a screw member adapted to be moved back and forth in the kick-off member to adjust the point at which the warping of the thermostatic arm It) becomes 7 effective to release the kick-off lever.

The actuating lever is provided with a suitable finger piece 3i to facilitate its manual operation. This finger piece has a shaft 32 which projects through a slot in the top of the housing and the top of this slot is kept closed by an arcshaped member 33. The finger piece 3! and the extension 33 may be held in place in any suitable manner. Inside of the housing is an are shaped member 33' which is mounted to move with the shaft 32 of the finger piece 3|. It may be The upper part of the frame is provided with a slot 35 and the switch member I2 is provided with a slot 36 to permit of the swinging motion of the spring I6.

The normal manual operation of the switch or circuit breaker is accomplished by simply moving the finger piece 3| from one side to the other so that the actuating arm |3 swings about the pivot 2| which is normally stationary. This action is similar to that of the well known snap action or toggle mechanism.

When the parts are in the closed circuit position of Fig. 2 and the thermostatic member |5 is warped suiiiciently by reason of heat created by the resistance to current passing through it, the upper end of the member |5 will be moved to the right out of the way of the screw tip 30. As a result the spring l6 which is pulling down against the pin 25 on the actuating lever will cause pressure to be applied through the actuating arm |3 against the pintle bearings 2| which are almost in line with the center of the pin 26, and the crosspiece 21. This immediately throws the actuating arm |3 toward the left and throws the switch member l2 toward the left until the movable end of the switch member strikesthe abutment l9 and the heel of the actuating lever 23 strikes the abutment 22 and the parts assume the position shown in Fig. 3, where the finger piece 3| is in a position approximately midway between the stop shoulders 24 and 25 which will be called a tripped position.

It will be seen that the actuating lever in moving from the position of Fig. 2 to the position of Fig. 3 has moved radially inward as the pintles 2| on the kick-on member |4 swing about the hinge or pivot 20. This opening of the circuit will occur even though an attempt is made to hold the actuating lever l3 in the on position. In this event the actuating lever will remain in approximately the same angular position of Fig. 2 except that it will move radially inward to a position intermediate that of Figs. 2 and 3.

To re-set the circuit breaker it is simply necessary to move the actuating lever from the position of Fig. 3 to the oiT position of Fig. 1. In this action the actuating lever swings about the trip of the heel 23 and the pintles 2| are lifted so as to tilt the kick-off member |4 about its hinge point 20 until the thermostatic member l5 can snap beneath the projection 30 and hold the kickoff member in the normal off position.

The circuit of the switch may then be closed by simply moving the actuating lever from the position of Fig. 1 to the position of Fig. 2 at which time the actuating lever swings about the pintles 2| which are now stationary.

From the foregoing it will be seen that the actuating lever has three positions, the open circult or off position of Fig. 1, the closed circuit or on position of Fig. 2 and the intermediate or tripped position of Fig. 3.

The lever M and the thermostatic arm |5 constitute one form of current responsive device or means for normally holding 'the operating member I3. in an operating position against the bias of the spring IE but adapted to release the operating member and break the circuit upon the occurrence of a predetermined overload current in the circuit controlled by the contact or switch arm l2.

scribed but the action is much the same. The mechanism is enclosed in a housing having a base IO and a top ID. ,The switch members 40 and 4| are like members I? and Hi respectively. Stationary contact 43 is connected to the supporting bushing 42 which may be connected to a bus bar 43 or other exterior circuit terminal. The frame member 44 is fixed to the base and has a transverse bearing 45 for the hinged switch contact member 4|. The latter is connected by a flexible lead 46 to the outer end of the bimetallic arm 41 whose lower end is secured to a support 48. The terminal member 49 carries the support 48 which is adjustable by screw 50 to vary the point of release of the thermostatic member 41. The member 49 has an external circuit connection 5|.

The kick-off member 52 is hinged on the same pin 45 which provides a bearing for the switch member 4|. This kick-off member has an insulating piece 53 which engages the hook on the outer end of the arm 41.

A wire yoke 54 is supported on the opposite arm of the kick-off member and has hinge bearings 55 which support the actuator 56. latter piece has a lug 51 to which the upper end of spring 58 is connected. The lower end of spring 58 is connected to the eye 59 on the switch member 4| so that when the actuator is moved from the oii position of Fig. 6 to the "on position of Fig. 7 the switch member will snap on and vice versa the circuit will be opened when the actuator is moved from right to left.

The finger piece 60 has a shaft 5| which extends into an opening in the upper end of the actuator 56. An outer are shaped piece 62 and an inner one 63 serve to keep the slot 64 closed. The finger piece 60 and its extension 62 may be secured on the shaft 6| in any suitable manner. The finger piece 60 and the member 63 may be held in place in any suitable manner.

When the parts are in the closed circuit position shown in Fig. 7 and the arm 41 is warped so as the release the kick-off member 52 the tension of the spring 58 pulls down on the actuator.

56 which in turn pulls down on the right end of the kick-off lever 52 and tilts the lever 52 and at the same time snaps the switch member 4| to the open circuit or ofi position. The inward or downward motion of the actuator is permitted by reason of the sliding connection of the shaft 6| in the outer end of the actuator.

When the arm 41 has cooled oiT and resumes its normal position the switch may be reset by swinging the actuator toward the left (Fig. 8), the trip position. The inclined lug 51 slides out- Wardly over the inclined edge 65 of the insulator 53 until the insulator snaps under the upper hooked end of the thermostatic arm 41 whereupon the switch may be actuated manually in the usual manner. It will be seen that a single spring suffices to effect the necessary snap action when the switch is actuated automatically as well as manually.

It should be noted that in both forms of the device, the placing of the moving contact, kickoff piece, and spring within the frame, with the U-shaped actuator outside of the frame and straddling the other parts makes it possible to confine the mechanism to a very small space.

During the trip position the kick-ofi piece and the frame in both forms cooperate to limit arcuate movement of the actuator, thus indicating the tripped position by the location of the. handie. In both forms movement of the handle to This g full "01? position will move the actuator arouately and this will pivot the kick-oft piece to reset the breaker. Resetting movement of the kick-01f piece will force the actuator radially outward into its position for normal operation. The preferred form uses the heel 23 to obtain a very strong direct lever action between the actuator and the kick-oil piece for the resetting movement. The form shown in Figs. 6 through 9 uses direct camming action of the lug 51 to accomplish positive resetting.

I claim:

1. A circuit breaker having a frame, a contact lever hinged to the frame, a kick-off member hinged to said frame, a current responsive .member normally restraining movement of said kick-off member, an actuating lever hinged to said kick-off member and a spring connecting.

said contact lever and said actuating lever and serving to snap the contact lever when the actuating lever is manually moved to the ofP' and on positions respectively to open and close the circuit and serving to open the circuit andmove the actuating member to a position intermediate the usual on and off position when the current responsive member releases the kick-off member.

2. In a circuit breaker device, a switch contact member hinged near one side of the'device, a kick-off lever hinged near the opposite side of the device, an actuator hinged to and movable with the kick-off lever, a spring connecting the actuator and the switch contact member, a current responsive member normally restraining the movement of the kick-off member and means moved with the kick-off member to move the switch contact member when the current responsive member releases the kick-off member.

3. In a circuit breaker, a hinged switch contact member, a hinged kick-off lever, an actuator hinged to and movable with the kick-off lever, a spring connecting the actuator and the switch contact member, a current responsive member normally restraining the movement of the kick-off member and a projection on the kick-ofi member to engage the switch contact member when the current responsive member releases the kick-off member.

4. A circuit breaker having a frame, a contact lever hinged to the frame, a kick-off member hinged to said frame, a current responsive member normally restraining movement of said kick-off member, an actuator hinged to said kick-off member and a spring connecting said contact lever and said actuator and serving to snap the contact lever when the actuator is manually moved to the off and on positions respectively to open and close the circuit and serving to open the circuit and move the actuator to a position intermediate the usual 011" and off position when the current responsive member releases the kick-ofi' member, saidfr'ame having stops for said actuator and said contact lever.

5. In a circuit breaker device, a switch 6ontact member hinged near one side of the device, a kick-off lever hinged near the opposite side of the device, an actuator hinged to and movable with the kick-ofi lever, a spring connecting the actuator and the switch contact member, a current responsive member normally restraining the movement of the kick-off member and means moved with the kick-off member to move the switch contact member when the current responsive member releases the kick-oif member, said kick-off member and spring serving to move the actuator to a tripped position when the kickoff member is released.

6. In a circuit breaker, a hinged switch contact member, a hinged kick-off lever, an actuator hinged to and movable with the kick-off lever, a spring connecting the actuator and the switch contact member, a current responsive member normally restraining the movement of the kick-oh member and. a projection on the kick-off member to engage the switch contact member when the current responsive member releases the kick-off member, said kick-off member and spring serving to move the actuator to a tripped position when the kick-off member is released. I

7. In a circuit breaker, a hinged switch contact member, a hinged kick-oil lever, an actuator hinged to and movable with the kick-off lever, a spring connecting the actuator and switch contact member, and a current 'respon sive member normally restraining the movement of the kick-off member, said contact member, kick-off lever and actuator being movable in the same vertical plane.

8. A circuit breaker comprising a support, switch member pivoted on said support, an operating member, a spring connected to said switch member and said operating member for biasing said switch member to a closed circuit position and said operating member to a predetermined position, supporting means movable upon a change in current conditions for holding said operating member in an operating position against its bias to said predetermined position, and means responsive to movement of said operating member to said predetermined position when released by said supporting means for moving said switch member to an open circuit position. Y,

9. A circuit breaker comprising a support, a contact arm pivoted on said support, an operating member, a spring connected to said contact arm and said operating member for biasing said operating member and said arm to closed circuit positions and said operating member to a second position, supporting means movable upon a change in current conditions for normally holding said operating member in an operating position against its bias to said second position, but releasing said operating member upon the occurrence of a predetermined current in the circuit controlled by said contact arm, and means responsive to movement of said operating member to said second position for actuating said contact arm to an open circuit position.

10. A circuit breaker comprising a support, a contact arm pivoted on said support, an operating member for said contact arm. an over-center spring connected to said contact arm and said operating member for b asing said operating member and said contact arm in either open circuit positions or closed circuit positions and continuously biasing said operating member to a thirdp sition. supporting means movable upon .a change in thermal current conditions for normally holding said operating member in an opcrating position against its bias to said third position, and means responsive to movement of said operating member to said third position when released by said supporting meansfor moving said contact arm to its open circuit position.

11. A circuit breaker comprising a base, a contact arm pivoted on said base, an over center spring having one end connected to said arm, an

operating member connected to the other end of said spring and movable to operate said con tact arm between two positions with a snap action, a support for said member pivotally mounted on said base, current responsive means normaliy securing said support in a predetermined position to tension said spring, and means responsive to movement of said support by said spring when said support is released by said cur rent responsive means for moving said contact arm to its open circuit position.

12. A circuit breaker comprising a base, a con-- tact arm pivoted on said base, an over-center spring having one end connected to said arm, an operating member connected to the other end of said spring and movable to operate said contact arm between closed and open circuit positions with a snap action, a support for said mem" ber movably mounted on said base, load responsive means for normally holding said support in position to tension said spring, and means responsive to movement of said support by said spring when said support is released by said load responsive means for moving said contact arm to its open circuit position, and a projection on said operating member engaging said base when said operating member is moved to open circuit position after operation of said load responsive means for returning said support to a position to be held by said overload responsive means.

13. A circuit breaker having a support, a switch member hinged to said support, a hinged member having an arm for engaging said switch member to move it toward an open circuit position, an actuating member pivoted to said hinged member and having an extension fulcrumed on the support, a toggle acting spring connecting said actuating member and said switch member, means releasable upon an overload for holding said hinged member in its nor-- mal position under normal load conditions, said spring moving said actuating member, said hinged member and said switch member to an open circuit position when said holding means is released upon an overload, said actuating member being tiltable about said fulcrum to reset the holding means.

14. A circuit breaker having a frame, a contact pivoted to said frame, a kick-ofi member pivoted to said frame, and engageabie with said contact, an actuator, means pivotally connecting said actuator and said kick-oil member, a

spring between said actuator and said contact, a current responsive device normally restraining pivotal movement of said i-ticit flfi member but actuated by abnormal current conditions to permit such movement, whereby the pivot connection between the actuator and iriciooif member is normally stationary so that pivotal zrovement of the actuator will cause the spring to move the contact to on and oft" positions and when the current responsive device permits pivoting oi the tick-off member the spring will cause movement of the actuator pivot, thus pivoting the kick-pit member to engage and move the contact to of! position, means on said kick-off member and said. frame cooperating to limit movement 01 the actuator when the kick-off is released, and means on the actuator engaging said kickmfi member whereby pivotal movement of said actuator will move said kick-off member against the action of said spring to restore the member into restraining relation with said current responsive device,

15. A circuit breaker having a frame, a con tact pivoted to said frame, a kick-off member pivoted to said frame and engageable with said contact, an actuator pivoted at one end to said kick-cit member, a spring between the other end of the actuator and the contact, a current responsive device normally restraining pivotal movement of said kIClbOfi member but actuated by abnormal current conditions to release said member, whereby the pivot oi! the actuator on the kick-off member is normally stationary so that movement of the actuator will cause the spring to move the contact to on and off positions and when the current responsive device releases the kick-off member the spring will cause movement of the actuator pivot, thus pivoting the kick-01f member to engage and move the contact to "oil?" position, means on said kick-oil member and said frame cooperating to limit movement of the actuator when the kick-off is released, said means including a portion on said actuator, spaced from the actuator pivot, engaging said frame whereby pivotal movement of said actuator will move the actuator pivot away from the part of the frame engaged by the actuator portion and force said kick-off member against the action of said spring to restore the member into restraining relation with said current responsive device.

RAYMOND N. ROWE.

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