Circuit Breaker With Spring Closing Means And Pawl And Rachet Spring Charging Means

Abstract

A circuit breaker characterized by stationary and movable contacts operable between open and closed positions, means including a crank shaft structure, pawl and rachet, and spring means for opening and closing the contacts, a toggle structure connected to the movable contact and comprising a first link, a second link, and a toggle lever; the first link being pivotally connected to the second link, the second link being pivotally connected to the toggle lever, the crank shaft structure having a cam surface movable against the joint of the links for moving the toggle structure from the open to the closed positions, first releasable latch means for retaining the toggle structure in the contacts closed position, stop means limiting movement of the first and second links beyond a position where a line through the pivotal connections of the first link and the movable contact mounting means and of the first and second links projects on the side of the pivotal connection of the second link and toggle lever opposite the crank shaft when the toggle structure is in the open position, and second releasable latch means for retaining the crank shaft in the spring charged position.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention:

This invention relates to circuit breakers of single pole or multi-pole type and, more particularly, it pertains to a stored energy mechanism therefore.

2. Description of the Prior Art:

Stored energy mechanisms for use in circuit breakers of a single pole or multi-pole type have been known in the art. A particular construction of such mechanisms is primarily dependent upon the parameters such as the rating of the circuit breaker. Suffice it to say, many stored energy mechanisms having closing springs cannot be charged while the circuit breaker is in operation. For that reason some circuit breakers have the disadvantage of not always being ready to close at a moments notice.

Associated with the foregoing is the disadvantage of some prior circuit breakers of having stored energy mechanism which are not completely insulated from live current carrying parts. Thus, all or part of the mechanism is "hot."

SUMMARY OF THE INVENTION

In accordance with this invention it has been found that a more desirable stored energy mechanism is provided which comprises stationary and movable contacts operable between open and closed positions, means including a crank shaft structure, pawl, and rachet, and spring toggle structure connected to the movable contact and comprising a first link, a second link, and a toggle lever; the first link being pivotally connected to the second link, the second link being pivotally connected to the toggle lever, the crank shaft structure having a cam surface movable against the joint of the links for moving the toggle means between the open and closed positions, first releasable latch means for retaining the toggle means in the contacts closed position, stop means comprising a fixed member on the side of the toggle means opposite the crank shaft structure for limiting movvement of the first and second links beyond a position where a line through the pivotal connections of the first link and the movable contact mounting means and of the first and second links projects on the side of the pivotal connection of the second link and toggle lever opposite the crank shaft when the toggle means is in the open position, and second releasable latch means for retaining the crank shaft in the spring charged position.

The advantage of the device of this invention is that it provides a circuit breaker having a stored energy mechanism in which the closing springs are charged while the breaker is in operation, whereby the circuit breaker is always ready to close.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of a circuit breaker taken on a line I--I of FIG. 3;

FIG. 2 is a horizontal sectional view taken on the line II--II of FIG. 1;

FIG. 3 is an end view taken on the line III--III of FIG. 1;

FIG. 4 is an enlarged end view of the spring charging means including a motor, pawl and rachet wheel;

FIG. 5 is a side view taken on the line V--V of FIG. 4;

FIG. 6 is an elevational view of the crank shaft;

FIG. 7 is a vertical sectional view taken on line Vii--V11 of FIG. 6;

FIG. 8 is a fragmentary isometric view of the operating mechanism in the spring charged contacts closed condition;

FIG. 9 is a fragmentary, isometric view of the operating mechanism in the spring charged, contacts open condition;

FIG. 10 is a fragmentary sectional view of the operating mechanism showing the springs in the discharged condition;

FIG. 11 is a fragmentary sectional view of the springs latched in the charged condition;

FIG. 12 is a fragmentary sectional view of the toggle system in the contacts closed position;

FIG. 13 is a fragmentary sectional view of the toggle system in the intermediate position; and

FIG. 14 is a fragmentary sectional view of the toggle system in the contact open position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 a circuit breaker is generally indicated at 10. It comprises movable contacts 12, stationary contacts 14, terminals 16 and 18, a mounting base 20, and an operating mechanism 22. In addition, the circuit breaker 10 includes a frame 24 comprising a pair of spaced upright support plates 26 (FIG. 3) and a top plate 28 extending between and is attached to the upper ends of the support plates 26.

The movable contacts 12 are mounted on a mounting arm 30 which is pivotally mounted on a pin 32 on upright portions 34 of the terminal 16 and the arm is movable between the closed (solid line) position and the open (broken line) position. The mounting arm 30 is pivotally mounted by pivot pin 32 on an upright portion 34 of the terminal 16. A mounting block 36 is secured to the upper side of the arm 30 to provide connection for a toggle structure of an operating mechanism 22.

The toggle structure comprises a first link 38, a second link 40, and a toggle lever 42. In addition to the toggle structure the operating mechanism 22 also comprises a crank shaft 44 for actuating the toggle structure from the open to the closed positions of the contacts 12 and 14. For that purpose spring means comprising a pair of charging springs 46 (one of which is shown in FIG. 1) are provided.

Moreover, the operating mechanism 22 comprises latch means including a latch lever 48 and a latch release member 50, which means releases the toggle structure from the closed to the open position of the contacts 12 and 14. A second latch means is provided for releasing the charging springs 46 from their charged position and said means includes a latch lever 52 together with a latch release member 54. The manner in which the latch release means including the lever 48 and 52 function is set forth hereinbelow. In addition, the operating mechanism 52 comprises stop means or toggle guide 56 for limiting movement of the first and second link 38 and 40 during the initial phase of movement of the toggle structure from the closed to the open positions of the contacts 12 and 14.

The several parts of the toggle structure are pivotally interconnected by pivot pins 58 and 60, the pivot pin 58 being disposed between the first and second links 38 and 40 and the pin 60 being disposed between the second link 40 and the lever 42. The lever 42 is rotatably mounted on a pivot pin 62, the end portions of which are seated in a U-shaped mounting bracket 64 which is attached to the top plate 28 (FIG. 3).

As shown more particularly in FIG. 3, the second link 40 comprises two spaced parallel links extending between the first link 38 and the toggle lever 42. The first link 38 comprises a single member the lower end of which is pivotally mounted on a shaft 66 which is journaled on the mounting block 36 and which extends (FIG. 3) in opposite directions to similar mounting blocks for the pole units on opposite sides of the unit shown in FIGS. 1 and 3. The first link 38 also includes a radially extending ridge 68 which extends peripherally of the upper journal portion surrounding the pivot pin 58. The ridge 68 engages an inclined upwardly extending portion of the toggle guide 56 (FIG. 1) which is secured rigidly to a frame member 70 by fastening means such as rivets 72. The joint between the first and second links 38 and 40 comprises the knee of the toggle structure for reasons set forth hereinbelow.

The upper end of the toggle structure which includes the toggle lever 42 operates in conjunction with the latch lever 48, the upper end of which is pivotally mounted by pivot pin 74. The opposite ends of the pin 74 are secured in the mounting brackets 64 (FIG. 2). The lower right end of the latch lever 48 has a roller 76 mounted on a pin 78. The roller engages a lower surface portion 80 of the toggle lever 42 and retains the lever in the position shown in FIG. 1. A ridge 82 of the lever 42 engages the periphery of the latch release member 50, thereby retaining the latch lever in the position shown in FIG. 1. The latch member 50 has a cutout portion or notch 84 and is provided with an actuation lever 86. A tension spring 88 extends from the mounting frame 24 to the lever 86 and normally retains the latch release member in the position shown with the notch 84 above the lower end of the ridge 82.

Ordinarily, when the contact 12 and 14 are in the enclosed position, as shown in FIG. 1, they are retained in that position with the toggle structure disposed in the generally arcuate position of the links 38, 40, and the toggle lever 42. A pair of tension springs 90, one of which is shown in FIG. 1, extend between the top plate 28 and the mounting block 36 so that in the contact closed position the mounting arm 30 is biased upwardly against the toggle structure with the knee or joint between the first link 38 and the second link 40 bearing against the toggle guide 56. As shown in FIG. 1 the toggle guide 56 is inclined upwardly and in a direction on the opposite side of the toggle structure that is the side on which the crank shaft 44 is disposed. Accordingly, the contacts 12 and 14 remain in the closed position so long as an extension of a line 92 extending through the axes of the pivot pin 58 and 66 is on the right side of the axes of the pivot pin 60. Similarly, the contacts 12 and 14 remain in the closed position so long as an extension of a line 94 extending to the axes of the pivot pin 60 and 62 extend to the right of the axes of the pin 58.

The contacts 12 and 14 are actuated to the open position when the toggle structure is released such as by rotating the latch release member 50 clockwise. For that purpose the actuation lever 86 may be rotated either manually or electrically such as by a suitably mounted solenoid until the notch 84 moves to a position below the lower end of the ridge 82. Because of the force applied to the toggle structure by the tension spring 90 when the notch 84 moves below the lower end of the ridge 82, the latch lever 48 is free to rotate counterclockwise and the upwardly inclined surface portion 80 of the toggle lever 42 causes the roller 76 to rotate and move the latch lever 48 counterclockwise until the lever reaches the position shown in FIG. 13.

AS the toggle lever 42 rotates counterclockwise from the position of FIG. 1 to that of FIG. 13, the pin 60 moves upwardly causing the knee or joint between the first and second links 38 and 40 to ride along the inclined surface of the toggle guide 56 until the axes line 92 is disposed to the left of the axes of the pivot pin 60. In the alternative, the axes line 94 is disposed on the right of the axes of the pin 58. In that position of the toggle structure the continued application of force by the tension springs 90 causes the contact arm 30 to continue to rotate about the pivot pin 32 until the toggle structure is fully unlatched as shown in FIG. 14. In that position the toggle lever 42 is returned to its original position (FIG. 1) and a wire spring 96 on the pivot pin 74 rotates the lever clockwise to the position in which the roller 76 is again located below inclined surface portion 80 of the toggle lever 80. Upon release of the actuation of the lever 86 the latch release member 50 is rotated counterclockwise by the tension spring 88 until the cutout portion 84 is above the lower end of the ridge 82.

The contacts 12 and 14 are returned to the closed position by moving the toggle structure from the collapsed position (FIG. 14) to the extended position (FIG. 12). For that purpose a toggle charging mechanism is provided which includes the crank shaft 44 and the pair of charging springs 46, one of which is shown in the drawing. The lower end of the springs 46 are attached to the mounting frames 24 at 100 (FIG. 1) and the upper ends of the springs are attached to the crank shaft by connecting links 102.

As shown in FIGS. 6 and 7 the crank shaft comprises axial end portions 104, eccentrics 106 to which the links 102 are connected, a cam 108 and radially extending interconnecting members including latches 110. The axial end portion 104 are journally mounted in the space support plate 26. The eccentrics 106 are provided with grooves 112 in which the links 102 are seated. The cam 108 is disposed at an angle to the axes of the in portions 104 and the eccentrics 106 and includes a peripheral surface 114 for engagement with the ridge 68 on the first link 38 when the springs are released to rotate the crank shaft for the purpose of moving the toggle structure from the collapsed position to the closed position of FIG. 12. The charging springs 98 are charged from the collapsed position of FIG. 10 to the charged position of FIG. 9 by suitable charging means such as a motor-operated rachet wheel 116 which is mounted on one axial end portion 104.

Although the rachet wheel 116 may be charged manually by conventional lever means, it is preferably charged automatically, a shown in FIGS. 4 and 5, by the use of an electric motor 118 together with a pawl 120 mounted on the lower end of a rocker arm 122 which is pivotally mounted on the pivot pin 124 which is attached to the support plate 26. The end of the shaft of the motor includes an eccentric 126 for oscillating the lever 122 and the pawl 120 thereon back and forth for driving the rachet wheel 116. A holding pawl 128 retains the rachet wheel 116 in position when the pawl 120 is retracted from contact by the rocker arm. The rocker arm 122 is biased in a direction away from the rachet wheel and against the surface of the eccentric 126 by a spring 130.

As the rachet wheel is rotated the crank shaft 44 turns approximately 180.degree. from the position shown in FIG. 10 to that shown in FIG. 11 where a line 132 extending from the axes of the eccentric 106 and the axes of the springs 98 is slightly below the axes of the axial end portions 104 of the crank shaft. In that position the springs 98 are free to rotate the crank shaft to the spring discharge position unless latch means are provided. For that purpose latch means including a latch lever 134 is provided and is pivotally mounted on a pin 136. The latch lever 134, being similar to the latch lever 48, is also provided with a roller 138 for engaging an inclined surface 140 at one end of the latch 106. Each latch 110 is provided with a similar latch means comprising a latch lever 134. Moreover, the latch means also includes a latch release member 142 having a notch 144 and an actuation lever 146. So long as the lower end portion of a ridge 148 engages the surface of the latch release member 142 below the notch 144, the lever 134 is secured in place and the latch 110 retains the springs 98 in the charged position.

In order to discharge the springs 98 the lever 146 is actuated to the left in order to rotate the latch release member 142 counterclockwise a distance sufficient to permit the ridge 148 to move into a notch 144 as a result of the pressure applied by the springs 98 through the latches 110 and the roller 138. Upon release of the latches 110 the springs 98 rotate the crank shaft 44 clockwise, whereupon the cam 108 (FIG. 9) moves the knee or joint between the first and second links 38 and 40 from the collapsed position to the extended (contacts closed) position of FIG. 12. After the cam 108 moves the toggle system to the extended position, it continues to rotate to the completely collapsed position of the springs 98 as shown in FIG. 10.

Accordingly, the device of the present invention achieves certain new and novel advantages which were not attained by prior circuit breakers of the type involved. Those advantages include a stored energy type mechanism in which the closing springs can be changed while the breaker is in operation, whereby the breaker is always ready to close. Another advantage is that the stored energy type mechanism is capable of being operated remotely by motor and rachet type gears or manually and can be tripped either manually or remotely by a solenoid. Finally, the stored energy type mechanism of this invention is completely insulated from live current-carrying parts so that no part of the mechanism is "hot."

Claims

What is claimed is:

1. A circuit breaker comprising a pair of contacts including stationary and movable contacts operable between open and closed positions and being biased in the open position, the movable contacts being mounted on a movable arm, a crank shaft structure, closing spring means connected to the crank shaft structure, a rachet wheel movable to move the crank shaft structure from a spring discharged position to a spring charged position to charge the closing spring means, operating means comprising pawl means operable to advance the ratchet wheel, toggle means connected to the movable contact for moving the contacts between the open and closed positions, the toggle means comprising first and second links and a toggle lever, the first link being pivotally connected to the movable contact, the second link being pivotally connected to the first link, the toggle lever being pivotally connected to the second link, the crank shaft structure having a cam surface movable against the toggle means for moving the toggle means from the open position to the closed position, first releasable latch means for holding the toggle means in the contacts closed position, stop means limiting movement of the first and second links beyond a position where a line through the pivotal connections between the first link and movable contact mounting arm and between the first and second links projects on the side of the pivotal connection of the second link and toggle lever opposite the crank shaft when the toggle means is in the open position, and second releasable latch means for retaining the crank shaft in the spring charged position.

2. The circuit breaker of claim 1 in which the first releasable latch means holds the toggle lever in the closed position.

3. The circuit breaker of claim 1 in which a line through the pivotal connections of the first an second links and of the second link and the toggle lever projects in the side of the pivotal connection of the first link and the movable contact mounting means opposite the crank shaft structure.

4. The circuit breaker of claim 1 in which a line through the pivotal connections of the first and second links and of the second link and the toggle lever projects on the side of the fulcrum toggle lever opposite the crank shaft structure.

5. The circuit breaker of claim 1 in which the stop means comprises a fixed member on the side of the toggle means opposite the crank shaft structure.

6. The circuit breaker of claim 5 in which the fixed member comprises cam surface means for guiding the toggle links in the direction of the crank shaft structure when the crank shaft structure is released from the spring charged position.

7. The circuit breaker of claim 6 in which the first link moves over the cam surface means with the projection of the line through the pivotal connections of the first link and movable contact moving toward the crank shaft upon release of the second releasable latch means.

8. The circuit breaker of claim 1 in which the pivotal connection of the second link and the toggle lever moves to the side of the projection of the line through the pivotal connections of the first link and movable contact when the first releasable latch means is released.

9. The circuit breaker of claim 6 in which the link moves into the path of movement of the cam surface means toward the spring charged position when the toggle means moves to the open position.

10. The circuit breaker of claim 9 in which the fixed member guides the first link into said path of movement of the cam surface means.