The invention relates to a circuit breaker, and more particularly to a fault indicator or a short-circuit indicator adapted for the circuit breaker.

A circuit breaker is designed to trip and turn OFF power during short-circuit or fault condition and indicate short-circuit or fault to the user. Generally, the handle of the circuit breaker gets tilted during a short circuit situation to indicate the short circuit situation which successively moves to its initial position to indicate that the circuit breaker is switched OFF. Thus, mere tilting of the handle of the circuit breaker does not convincingly indicate exact operating condition of the circuit breaker to a remote observer.

There are various indication mechanisms such as buzzers, light indicators and the like are also used in the art to indicate short-circuit condition, but these indication mechanisms indicate short-circuit condition by creating a buzz or an illumination at the time of the short-circuit. For example, in EP1703533, a short-circuit condition is indicated by an indication mechanism visible on the circuit breaker. The indication mechanism is indicated by a flag that is visible to a user. The flag is mounted on a rotating drum. A solenoid of the circuit breaker acts on the rotating drum. The rotating drum is also connected to a handle of the circuit breaker. However, an erroneous situation may arise if the rotating drum gets blocked. In such situation, the circuit breaker might mal-function and an indication of the short-circuit condition might be erroneous.

Document US 2006/097829 A1 discloses a circuit breaker device having a mechanism for indicating an ON condition, a TRIPPED condition and an OFF condition. The mechanism comprises a slider (a solenoid plunger) connected to a solenoid coil and movable between first and second positions responsive to the operating conditions. A rotating arm is connected to the slider and has an indication flag mounted thereon for indicating the plurality of operating conditions. Therefore, there exists a need of a short-circuit indicator mechanism for a circuit breaker that overcomes all the drawbacks of the prior art.

An object of the present invention is to provide a remote indication of a plurality of working conditions of a circuit breaker that gives a remote indication of an operating condition, a short-circuit condition and/or an OFF condition of the circuit breaker to a distant observer.

The present invention discloses a circuit breaker device having a short-circuit indicator mechanism adapted for indicating a normal operating condition, a short-circuit condition and an OFF condition of the circuit breaker. The short-circuit indicator mechanism comprises a slider that is having a first end and a second end. The first end of the slider connects to a first hook. The second end of the slider connects to a solenoid. The slider slidably moves between a first position and a second position responsive to a plurality of operating conditions of the circuit breaker. The short-circuit indicator mechanism includes a rotating arm that is having a second hook connected thereto. The second hook engages with the first hook in the first position of the slider. The second hook disengages with the first hook in the second position of the slider. The rotating arm is having an indication flag mounted thereon. The indication flag is adapted for indicating the plurality of operating conditions of the circuit breaker. The rotating arm includes a slot adapted to accommodate a pin that assists in a movement of the rotating arm in response to the plurality of operating conditions. The slider includes a spring extending between a body of the slider and the rotating arm adapted for assisting a counterclockwise rotation of the rotating arm.

• FIG. 1 is a front view of a short-circuit indicator mechanism constructed in accordance with the present invention illustrating a normal operating condition of a circuit breaker;
• FIG. 2 is a front view of the short-circuit indicator mechanism of FIG. 1 illustrating a short-circuit condition of the circuit breaker; and
• FIG. 3 is a front view of the short circuit indicator mechanism of FIG. 1 illustrating an OFF condition of the circuit breaker.

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

Referring to FIG. 1, a circuit breaker 100 having a short-circuit indicator mechanism constructed in accordance with a preferred embodiment of the present invention is shown. The short-circuit indicator mechanism includes a solenoid 102, a slider 104, a rotating arm 110, and an indication flag 114. The slider 104 is having a first end that includes a first hook 106. The first hook 106 is preferably positioned substantially perpendicular to the first end. The slider 104 is having a second end that connects to the solenoid 102 via an annular collar 118. The slider 104 is removably connectable in this one preferred embodiment. The slider 104 is linearly movable between a first position and a second position. The solenoid 102 assists in the linear movement of the slider 104 between the first and second positions responsive to a plurality of operating conditions of circuit breaker 100. In this one particular embodiment, the slider 104 remains in the first position in a normal operating condition of the circuit breaker 100. The slider 104 moves to the second position during a short-circuit condition of the circuit breaker 100. The short-circuit indicator mechanism includes a spring 103 that extends between a body of the slider 104 and the rotating arm 110. The spring 103 substantially pushes the slider 104 against the solenoid 102. The spring 103 also assists in a counterclockwise rotation of the rotating arm 110 in this one particular embodiment.

The rotating arm 110 is mounted on a housing of the circuit breaker 100 along a pivot 112. The rotating arm 110 includes a second hook 108 that respectively engages and disengages with the first hook 106 depending upon the operating condition of the slider 104. The rotating arm 110 includes an elongated slot that engages with a movable pin such that the pin is movable within the elongated slot per the movement of a movable contact of the circuit breaker 100 in this one particular embodiment. The pin moves to an intermediate position inside the slot when the movable contact of the miniature circuit breaker 100 disengages with the fixed contact in the short-circuit condition.

The pin is configured to move inside the elongated slot and align to an edge of the slot to move the rotating arm 110 per the movement of a handle 120 of the circuit breaker 100. The handle 120 is configured to open and close the movable contact of the circuit breaker 100 to preferably switch ON and switch OFF the circuit breaker 100. However, it is understood that the rotating arm 110 remains stationary if the short-circuit condition is not verified.

The short-circuit indicator mechanism includes an indication flag 114 that indicates the operating condition of circuit breaker 100 in this one preferred embodiment. The short-circuit indicator mechanism further comprises a window 116 preferably located on the housing of circuit breaker 100 such that the indication flag 114 is visible through the window 116. In this one embodiment, the indication flag 114 is visible through the window 116 during the short-circuit condition of the circuit breaker 100. However, the flag 114 is invisible through the window 116 during a normal operating condition of the circuit breaker 100.

As shown in FIG. 1, the circuit breaker 100 is in the normal operating condition. In the normal operating position the handle 120 is in an ON position. In this condition, the solenoid 102 is in a retracted position and the slider 104 is in a first position. In this condition, the first hook 106 and the second hook 108 are engaged with each other. In this condition, the indication flag 114 is not visible through the window 116.

Referring now to FIG. 2, a short circuit condition of the circuit breaker 100 is shown. In the short circuit condition, the solenoid 102 reacts and moves the slider 104 to a second position. In the second position, the slider 104 moves such that the first hook 106 disengages from the second hook 108 to facilitate rotation of the rotating arm 110. In this condition, the indication flag 114 is visible through the window 116 to indicate the short-circuit condition of the circuit breaker 100.

As shown in FIG. 3, the circuit breaker 100 is an OFF condition wherein the handle 120 shifts to an OFF position. In this condition, the solenoid 102 retracts to an original position to move the slider 104 back to the first position. In the first position, the first hook 106 and the second hook 108 contact without getting engaged with each other. In this condition, the indication flag 114 remains visible through the window 116 thereby indicating the short-circuit condition of the circuit breaker 100.

1. 1. The solenoid 102 is capable of reacting to a change in an operating condition of the circuit breaker 100 that advantageously assists in the linear movement of the slider 104 as per the operating condition of the circuit breaker 100.
2. 2. The spring 103 extends between the body of the slider 104 and the rotating arm 110 to advantageously push the slider 104 against the solenoid 102 for enabling the rotating arm 110 to rotate in a counterclockwise direction.
3. 3. The slider 104 is capable of moving linearly between the first and second positions to respectively define the operating condition and the short-circuit condition of the circuit breaker 100.
4. 4. The window 116 is advantageously provided on the housing of the circuit breaker 100 such that the indication flag 114 is visible through the window 116 during the short-circuit condition and the flag 114 is invisible during the normal operating condition.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were, chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated.