Circuit Breaker With Manual Trip Structure

Abstract

A molded case type circuit breaker comprises an externally operable trip structure manually operable to an actuating position to trip the breaker with means for padlocking the trip structure in the actuating position.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Circuit breakers of the type comprising a trip bar movable to a tripped position to effect automatic opening of the breaker contacts.

2. Description of the Prior Art

As will be hereinafter set forth with reference to the patent to A.R. Cellerini U.S. Pat. No. 3,296,564 issued Jan. 3, 1967, the application of Eugene J. Walker et al. Ser. No. 700,251 filed Jan. 24, 1968 and the application of James P. Ellsworth et al. Ser. No. 9370 filed Feb. 6, 1970, it is old in the art to provide molded case type circuit breakers with internal mechanisms of the type herein disclosed. This invention covers a molded case type circuit breaker comprising an externally operable manual trip structure with means for padlocking the trip structure in the trip actuating position.

SUMMARY OF THE INVENTION

A circuit breaker comprises an insulating housing having an opening therein and a circuit breaker structure supported in the housing. The circuit breaker structure comprises a pair of contacts and a latched releasable member releasable to effect automatic opening of the contacts. The circuit breaker structure also comprises a trip member movable from an initial position to a tripped position to effect release of the releasable member. A manual trip structure, supported on the housing at the opening in the housing, comprises a shroud and a trip actuator supported in the shroud which trip actuator is biased to an inoperative position. The trip actuator is manually movable in the shroud through the opening in the housing against the bias of the biasing means to move the trip member to the tripped position. The shroud is provided with a padlock-receiving opening therein for receiving the hasp of a padlock that may be used to lock the trip actuator in a position wherein the trip actuator maintains the trip member in the tripped position. Stop means in the housing limits movement of the trip member in the tripping direction and the connection between the trip actuator and trip member is a resilient connection which enables movement of the trip actuator an additional distance after the trip member has been stopped. The trip actuator is moved the additional distance in order to clear the opening in the shroud for reception of the hasp of a padlock.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a multi-pole molded case type circuit breaker constructed in accordance with the principles of this invention;

FIG. 2 is a sectional view taken generally along the line II--II of FIG. 1;

FIG. 3 is a partial view illustrating the position of the trip actuator and trip bar when manually moved to trip the circuit breaker; and

FIG. 4 is a view similar to FIG. 3 showing the additional movement of the trip actuator to clear the opening in the shroud for the reception of the hasp of a padlock.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, there is shown, in FIGS. 1 and 2, a molded case or insulating housing type three-pole circuit breaker 5. The circuit breaker 5 comprises an insulating base 7 and an insulating cover 8 secured to the base 7 to house the internal parts of the breaker. The base 7 and cover 8 are molded with cooperating insulating barriers that separate the housing into three adjacent compartments for housing the three-pole units of the circuit breaker in a manner well known in the art. In each pole unit, a circuit extends from a solderless terminal connector 9 through a stationary conductor 11, a stationary conductor 13, stationary contact means 15, movable contact means 17 of a movable contact structure indicated generally at 19, movable contact means 21 of the movable contact structure 19, stationary contact means 23, a stationary conductor 25 to another solderless terminal connector 27. The circuit also includes stationary arcing contact means 29 mounted on the stationary conductor 25 and movable arcing contact means 31 mounted on the movable contact structure 19. Each of the movable contact structures 19 is mounted for pivotal movement on a pivot pin 35, and all three of the movable contact arm structures 19 are connected together for simultaneous movement by means of an elongated tie bar 37. The details of construction and operation of the stationary and movable contacts are move specifically described in the above-mentioned patent application of Eugene J. Walker, Ser. No. 700,251 filed Jan. 24, 1968.

The movable contact arm structures 19 for the three-pole units are moved between closed and open positions by operation of an operating mechanism, indicated generally at 39, of the type more specifically described in the above-mentioned patent application of Eugene J. Walker et al. Ser. No. 700,251. The operating mechanism 39 is a single operating mechanism in the center pole unit of the circuit breaker. The operating mechanism 39 comprises a lower toggle link 41 that is connected to the movable contact structure 19 of the center pole unit by means of a pin 43. The lower toggle link 41 is connected to an upper toggle link 45 by means of a knee pivot pin 47. The upper toggle link 45 is connected to a releasable trip member 49 by means of a pin 51. The releasable trip member 49 is pivotally supported at one end thereof on a pin 53 that is supported on a pair of supporting plates 55. The releasable trip member 49 is latched at the other end thereof by means of a latch structure, indicated generally at 57, of the type more specifically described in the patent application of James P. Ellsworth et al. Ser. No. 9,370 filed Feb. 6, 1970. The operating mechanism 39 comprises an inverted generally U-shaped operating lever 61 that is supported for pivotal movement at the inner ends of the legs thereof on pin means 63 supported on the supporting plates 55. Over-center tension springs 65 are connected at the lower end thereof to the knee pivot 47 and at the upper end thereof to the bight portion of the operating lever 61. The housing cover 8 is provided with an opening 67 therein, and an insulating handle 69, which is secured to the front of the operating lever 61, extends through the opening 67 to permit manual operation of the circuit breaker.

The circuit breaker is shown in the closed position in FIG. 2. In order to manually open the circuit breaker the operating handle 69 is moved in a clockwise (FIG. 2) direction to move the operating lever 61 clockwise about the pivot 63. This movement carries the overcenter springs 65 to the right to collapse the toggle 41, 45 to simultaneously move the three contact arm structures 19 of the three-pole units to the open position. In order to manually close the circuit breaker, the operating handle 69 is moved in a counterclockwise direction back to the closed position seen in FIG. 2. During this movement, the tension springs 65 are moved to the left to erect the toggle 41, 45 to thereby move the three contact arm structures 19 to the closed position seen in FIG. 2.

The releasable member 49 is latched in the position seen in FIG. 2 by means of the latch structure 57 which comprises a latch member 71 that latches the latch structure 57 in the latching position and that is in turn latched in the latching position by a latch part 75 of a trip bar 77. The structure and operation of the latch structure 57 are of the type described in FIGS. 1-3 of the aforementioned patent application of James P. Ellsworth et al. Ser. No. 9,370. The trip bar 77 is part of a trip device indicated generally at 79 that is more specifically described in the above-mentioned patent to A.R. Cellerini U.S. Pat. No. 3,296,564. Thus, only a brief description of the trip device 79 is provided herein. The trip bar 77 is an elongated insulating trip bar that extends across the three-pole units of the circuit breaker and is supported for movement about the elongated axis 81 thereof which axis 81 is normal to the plane of the paper as seen in FIG. 2. The trip device 79 comprises a separate electro-magnetic trip stricture, indicated generally at 85, in each pole unit that operates upon the occurrence of a severe overload in the associated pole unit to move a rod member 87 downward to rotate the trip bar 77 in a clockwise direction about the axis 81 to the tripped position to trip the breaker in a manner to be hereinafter described. The trip device 79 also comprises a thermal trip structure, indicated generally at 91, in each pole unit with each terminal trip structure 91 comprising a bimetal 93 that is heated and flexes to the left with a time delay upon the occurrence of a lesser overload in the associated pole unit to operate against a depending projection 95 of the trip bar 77 to rotate the trip bar clockwise about the axis 81 to the tripped position. Upon rotation of the trip bar 77 to the tripped position the latch part 75 thereof releases the latch part 71 of the latch structure 57 to effect release of the releasable member 49. Upon release of the releasable member 49, the springs 65 operate to move the releasable member 49 in a counterclockwise direction about the pivot 53 collapsing the toggle 41, 45 to move the contact arm structures 19 to the open position. With the releasable trip member 49 in the tripped position, the circuit breaker cannot be operated to the closed position until the trip member 49 is reset and relatched in the position seen in FIG. 2. The releasable member 49 is reset and relatched by movement of the operating handle 69 to a position slightly past the full "off" position. During this movement, a depending projection 101 on the operating lever 61 operates against a shoulder portion 103 on the releasable member 49 to pivot the releasable member 49 in a clockwise direction about the pivot 53 to the reset and relatched position wherein the releasable member 49 is automatically relatched by the latch structure 57 which is automatically relatched by the latch part 75 of the trip bar 77 in a manner well known in the art. Following resetting of the releasable member 49 the circuit breaker can then be manually and automatically operated in the same manner as was hereinbefore described.

As can be seen in FIGS. 2-4, the trip bar 77 is biased back to the latching position by means of a coil compression spring 107 that is supported between the part 95 and the housing 73 of the trip device.

The circuit breaker 5 is provided with an improved manual trip structure indicated generally at 111. As can be understood with regard to FIG. 1, the section line II--II goes first through the center pole unit to illustrate the operating mechanism and latch mechanism which is in the center pole unit and then jogs down to the one outside pole unit to illustrate the manual trip structure 111 which is disposed over the trip bar 77 at the one outside pole unit. The manual trip structure 111 comprisea a tubular metallic shroud 113 that extends through an opening 115 (FIGS. 2-4) in the insulating cover 8 and is riveted over at 117 to support the shroud 113 on the cover 8. The shroud 113 protects the trip actuator 119 from accidental actuation. The shroud 113 also provides for padlocking in a manner that will be hereinafter described. A push-button type manual trip actuator 119 is supported for movement in the shroud 113. The manual trip actuator 119 is biased to the inoperative position seen in FIG. 2 by means of a coil spring 121 that engages under the head portion of the trip actuator 119. Frontward movement of the trip actuator 119 is limited by a pin 123 that extends through a small-diameter portion of the trip actuator 119 and engages the shroud 113 at the opposite ends thereof. A coil spring 125 is supported on the trip actuator 119 engaging the pin 123 and a shoulder surface 127 on the trip actuator 119. As can be understood with reference to FIGS. 3-5, the coil spring 125 can be rotated counterclockwise with relation to FIG. 1 to operate against the pin 23 to thread the spring frontward to provide a frontward adjustability of the position of the spring 125. A rigid metallic member 131 is positioned just below the spring 125 and secured to the insulating trip bar 77 by a suitable securing screw 133. The shroud 113 is provided with a padlock receiving opening 135 for receiving the hasp 137 (FIG. 4) of a padlock to enable padlocking of the manual trip structure 111 in a manner to be hereinafter described.

The circuit breaker is shown in FIG. 2 in the closed position. When it is desired to manually trip the circuit breaker 5, an operator manually depresses the trip actuator 119 moving the trip actuator from the inoperative position seen in FIG. 2 to the tripped position seen in FIG. 3. During this movement, the spring 125, which is stronger than the spring 107 of the trip bar 77 operates against the arm 131 to move the trip bar 77 to the tripped position seen in FIG. 3. Movement of the trip bar 77 to the tripped position seen in FIG. 3 operates to release the latch structure 57 to trip the circuit breaker 5 in the same manner as was hereinbefore described with regard to the thermal and electro-magnetic tripping operations. Upon release of the trip actuator 119, the spring 121 will bias the trip actuator 119 back to the inoperative position seen in FIG. 2, and the circuit breaker can be relatched in the same manner as was hereinbefore described. As can be understood with reference to FIG. 3, the opening 135 in the shroud 113 is not fully cleared when the trip bar 77 is moved to the tripped position, and the projection 95 on the trip bar 77 engages the housing 73 of the trip device to limit tripping movement of the trip bar 77. The resilient operative connection of the spring 125 with the part 131 of the trip bar 77 enables further depression of the trip actuator 119 past the position wherein the trip bar 77 is stopped which additional movement puts the trip actuator 119 in the position seen in FIG. 4 wherein the opening 135 is clear for the reception of the hasp 137 of a padlock. When it is desired to padlock the manual trip structure 111, the trip actuator 119 is depressed to the padlock receiving position seen in FIG. 4 clearing the opening 135 in the shroud 113 and the hasp 137 of the padlock is passed through the opening 135 to thereby lock the trip actuator 119 in the position seen in FIG. 4 to thereby lock the trip bar 77 in the tripped position. With the trip bar 77 locked in the tripped position, the releasable trip member 49 cannot be relatched and the circuit breaker cannot be operated to the closed position.

Claims

We claim as our invention:

1. A circuit breaker comprising an insulating housing having a pair of openings therein, a circuit breaker structure supported in said housing, said circuit breaker structure comprising a pair of contact structures and a latched releasable member releasable to effect automatic opening of said contact structures, an operating handle extending through a first of said openings and being manually operable to open and close said contacts, a trip member movable from an initial position to a tripped position to effect release of said releasable member, a manual trip structure supported on said housing at the second of said openings, said manual trip structure comprising a tubular shroud supported on said housing, a trip actuator supported in said tubular shroud, biasing means biasing said trip actuator to an inoperative position, said trip actuator being manually movable in said tubular shroud and through said second opening against the bias of said biasing means to move said trip member to said tripped position, and said manual trip structure comprising means for receiving a padlock that may be used to lock said trip actuator in a position wherein said trip actuator maintains said trip member in said tripped position.

2. A circuit breaker according to claim 1, and said tubular shroud having a padlock receiving opening therein for receiving the hasp of a padlock that may be used to lock said trip actuator in said position wherein said trip actuator maintains said trip member in the tripped position.

3. A circuit breaker according to claim 2, said trip actuator being a push-button type member movable rectilinearly in said tubular shroud and through said second opening.

4. A circuit breaker according to claim 2, and resilient means between said trip actuator and said trip member for actuating said trip member upon movement of said trip actuator.

5. A circuit breaker according to claim 3, and resilient means between said trip actuator and said trip member for actuating said trip member upon movement of said trip actuator.

6. A circuit breaker according to claim 5, said trip actuator being movable in said tubular shroud from said inoperative position to an actuating position to operate through said resilient means to move said trip member to said tripped position, stop means in said housing limiting movement of said trip member in the tripping direction, said trip actuator being movable past said actuating position to a padlocking position to clear said padlocking receiving opening for reception of the hasp of a padlock, and said resilient means being compressed after said stop means limits movement of said trip member to thereby permit movement of said trip actuator to said padlocking position.

7. A circuit breaker according to claim 6, a first coil spring in said tubular shroud biasing said trip actuator to the inoperative position, said trip actuator comprising a rod portion extending through said second opening, a pin member extending through said rod portion inside said housing to limit frontward movement of said trip actuator, and a coil spring supported on said rod portion and retained in position by said pin member to provide said resilient connection between said trip actuator and said trip member.