CLIAMS:We Claim:

1. A status indication assembly (100) for mechanism springs (150) of a circuit breaker (200), the circuit breaker (200) having an operating mechanism (170) and a micro-switch (180), the operating mechanism (170) having a plurality of mechanical linkages, a pair of side plates (160), a charging shaft and the mechanism springs (150), the charging shaft being capable of connecting the pair of side plates (160), the status indication assembly (100) comprising:
a first ratchet (20) and a second ratchet (40) parallely mounted on the charging shaft such that the second ratchet (40) lies behind the first ratchet (20), the first ratchet having a plurality of tooth (10A), the plurality of tooth (10A) having a last tooth (10A') with more height as compared to rest of teeth of the first ratchet (10), the second ratchet having a plurality of tooth, the plurality of tooth (30A) having a last tooth (30A') with more height as compared to rest of teeth of the second ratchet (20), the ratchets (20, 40) connected to a handle;
a pawl (60) being capable of rotating to disengage from the ratchets (20, 40) during charging stroke of the handle and engaging to get locked/ latched against successive tooth of the ratchets (20, 40) at end of each charging stroke, the pawl having a protrusion (44), a hole (48) and a notch (52); and
a rotary component (80) concentrically mounted on a pin fixed on the same plate having the ratchets (20, 40) and the pawl (60) mounted thereon, the rotary component (80) being capable of rotating around the pin in any one of a clockwise direction and an anticlockwise direction, the rotary component having
a pair of grooves (64) configured on a bottom surface thereof, the pair of grooves (64) adapted to receive a torsion spring therein,
a first link (68) configured on one side thereof, the first link (68) capable of being actuated by the protrusion (44) of the pawl (60), and
a second link (72) configured on another side thereof, the second link (72) being capable of pressing and un-pressing the micro-switch (180) during a charging state and a discharging state of the mechanism springs (150) thereby providing electrical indication for charging/discharging status of the mechanism springs (150),
wherein, when the mechanism springs are completely charged, the pawl becomes free and rests on the last tooth (10A', 30A') of the ratchets (20, 40) thereby allowing the pawl to undergo more angular rotation to facilitate the protrusion (44) of the pawl (60) to press the first link (68) of the rotary component (80) through more distance causing the rotary component (80) to undergo more anticlockwise rotation and further rotation of the second link (72) in the anticlockwise direction to release the micro-switch (180) actuation to change state thereof to indicate charging/discharging status of the mechanism springs (150).

2. The status indication assembly (100), wherein the pawl (60) is mounted through the hole (48) on a pin fixed on the same plate having ratchets (20, 40) mounted thereon.

3. The status indication assembly (100), wherein the second link (72) is longer in length than the first link (68).

4. The status indication assembly (100), wherein the handle is rotated by any one of a manual means and an electrical means.

,TagSPECI:Field of the invention

The present invention relates generally to switching devices and more particularly, to a status indication assembly for mechanism springs of a circuit breaker.

Background of the invention

An electrical circuit breaker is defined as a unit designed to connect, carry, disconnect and protect equipments connected in an electrical circuit from damage caused by overload, under-voltage or short circuit. There are two popular versions of the circuit breakers namely, a fixed type and a draw-out type. In both the types, a mechanism arrangement is used to close / trip the breaker poles simultaneously.

An operating mechanism of the circuit breaker having a moving contact and a stationary contact is switched ON (closed) or OFF (tripped) by using energy stored in a compressed or stretched spring mounted on the operating mechanism. With use of a charging handle, mechanism springs are transferred to compressed state and thus energy is stored therein. When the circuit breaker is closed, energy stored in the compressed mechanism spring is dissipated for closing all poles of the breakers through a pole shaft connected between operating mechanism and the poles. As soon as energy in the mechanism springs is converted into 'work', mechanism springs get relaxed and return to their normal position. In the prior art, a micro-switch operated by a charging motor is used to indicate charged/discharged status of mechanism springs. Also, the prior art indication systems are provided as only factory fitted accessory.

Accordingly, there is a need of a status indication assembly for mechanism
springs of a circuit breaker that overcomes the above mentioned drawbacks of the prior art.

Object of the invention

An object of the present invention is to indicate charged and discharged state of mechanism springs.

Summary of the invention

Accordingly, the present invention provides a status indication assembly for mechanism springs of a circuit breaker. The circuit breaker comprises an operating mechanism and a micro-switch. The operating mechanism comprises a plurality of mechanical linkages, a pair of side plates, a charging shaft and the mechanism springs. The charging shaft connects the pair of side plates.

The status indication assembly comprises a first ratchet, a second ratchet, a pawl and a rotary component. The first ratchet and the second ratchet are parallely mounted on the charging shaft such that the second ratchet lies behind the first ratchet. The first ratchet comprises a plurality of tooth. The plurality of tooth includes a last tooth with more height as compared to rest of teeth of the first ratchet. The second ratchet comprises a plurality of tooth. The plurality of tooth includes a last tooth with more height as compared to rest of teeth of the second ratchet. The ratchets are connected to a handle. The handle is rotated by any one of a manual means and an electrical means.

The pawl is capable of rotating to disengage from the ratchets during charging stroke of the handle and engaging to get locked/ latched against successive tooth of the ratchets at end of each charging stroke. The pawl comprises a protrusion, a hole and a notch. The pawl is mounted through the hole on a pin fixed on the same plate having ratchets mounted thereon.
The rotary component is concentrically mounted on a pin fixed on the same plate having the ratchets and the pawl mounted thereon. The rotary component rotates around the pin in any one of a clockwise direction and an anticlockwise direction. The rotary component comprises a pair of grooves, a first link and a second link.

The pair of grooves is configured on a bottom surface of the rotary component. The pair of grooves is adapted to receive a torsion spring therein. The first link is configured on one side of the rotary component. The first link is adapted to get actuated by the protrusion of the pawl. The second link is configured on another side of the rotary component. The second link is capable of pressing and un-pressing the micro-switch during a charging state and a discharging state of the mechanism springs thereby providing electrical indication for charging/discharging status of the mechanism springs. The second link is longer in length than the first link.

When the mechanism springs are completely charged, the pawl becomes free and rests on the last tooth of the ratchets thereby allowing the pawl to undergo more angular rotation to facilitate the protrusion of the pawl to press the first link of the rotary component through more distance causing the rotary component to undergo more anticlockwise rotation and further rotation of the second link in the anticlockwise direction to release the micro-switch actuation to change state thereof to indicate charging/discharging status of the mechanism springs.

Brief description of the drawings

Figure 1 shows a side and isometric views of a status indication assembly for mechanism springs of a circuit breaker, in accordance with the present invention;

Figure 2 shows a side view of the status indication assembly showing an intermediate stage of charging of the mechanism springs, in accordance with the present invention;
Figure 3 shows another side view of the status indication assembly showing the intermediate stage of charging of the mechanism springs, in accordance with the present invention;

Figure 4 shows ratchets of the status indication assembly of figure 1;

Figure 5 shows a pawl of the status indication assembly of figure 1; and

Figure 6 shows a rotary component the status indication assembly of figure 1.

Detailed description of the invention

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.

The present invention provides a status indication assembly for mechanism springs of a circuit breaker. The status indication assembly provides an electrical indication of the mechanism springs in any one of a charged/ compressed state and a discharged or energy dissipated/ relaxed state.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figures 1-6, a status indication assembly (100) (hereinafter “the assembly (100)”) for mechanism springs (150) of a circuit breaker (200) in accordance with the present invention is shown. The circuit breaker (200) comprises an operating mechanism (170) and a micro-switch (180). The operating mechanism (170) comprises a plurality of mechanical linkages (not shown), a pair of side plates (160), a charging shaft (not numbered) and the mechanism springs (150). The operating mechanism (170) drives the circuit breaker (200) to any one of ON and OFF positions. The mechanism springs (150) are capable of undergoing extension/contraction during switching ON/OFF condition of the circuit breaker (200). The charging shaft connects the pair of side plates (160).

The assembly (100) comprises a first ratchet (20), a second ratchet (40), a pawl (60) and a rotary component (80). The ratchets (20, 40), the pawl (60) and the rotary component (80) are fixed on one plate (not numbered) of the pair of side plates (160). In an embodiment, the ratchets (20, 40), the pawl (60) and the rotary component (80) are fixed on the same plate.

The ratchets (20, 40) are parallely mounted on the charging shaft such that the second ratchet (40) lies behind the first ratchet (20). The rotation of the ratchets (20, 40) causes rotation of the charging shaft. The ratchets (20, 40) include a plurality of tooth (10A, 30A). In an embodiment, a last tooth (10A') of the plurality of tooth (10A) of the first ratchet (20) and a last tooth (30A') of the plurality of tooth (30A) of the second ratchet (40) has more height as compared to rest of the teeth of the ratchets (20, 40). The ratchets (20, 40) are connected to a handle (not shown). The handle is rotated by any one of a manual means and an electrical means. The rotation of the handle causes engagement and disengagement of the pawl (60) with the ratchets (20, 40) on each charging stroke.

The pawl (60) includes a protrusion (44), a hole (48) and a notch (52). The pawl (60) is mounted on a pin (not shown) through the hole (48). The pin is fixed on the same side plate having ratchets (20, 40) mounted thereon. The protrusion (44) is configured on one side (not numbered) of the pawl (60). The protrusion (44) is adapted to press/actuate the rotary component (80) thereby allowing rotation of the rotary component (60) through a desired angle during each stroke while charging. During each stroke, as the pawl (60) gets rotated, the protrusion (44) of the pawl (60) presses the rotary component (80).

The rotary component (80) is concentrically mounted on a pin (not numbered) fixed on the same plate having the ratchets (20, 40) and the pawl (60) mounted thereon. The rotary component (80) rotates around the pin through the desired angle in any one of a clockwise direction and an anticlockwise direction. The rotation of the rotary component around the pin is facilitated by a torsion spring (not shown). In an embodiment, the rotary component (80) is a cylindrical component.

The rotary component (80) includes a pair of grooves (64), a first link (68) and a second link (72). The pair of grooves (64) is configured on a bottom surface (not numbered) of the rotary component (80). The torsion spring is located/ positioned inside the pair of grooves (64) through ends thereof thereby creating a stressed condition of the torsion spring resulting in the rotation of the rotary component (80). The stressed condition also assists the rotary component (80) to rotate in the anticlockwise direction to return to an original position when the pawl (60) rotates in a clockwise direction.

The first link (68) is configured on one side (not numbered) of the rotary component (80). The first link (68) is adapted to get actuated by the pawl (60). The second link (72) is configured on another side (not numbered) of the rotary component (80). In an embodiment, the second link (72) has more length than the first link (68). The second link (72) is used to press and un-press the micro-switch (180) during a charging state and a discharging state of the mechanism springs (150). The second link (72) keeps the micro-switch (180) pressed until the mechanism springs (150) are completely charged. In an embodiment, the second link (72) facilitates change in state of the micro-switch (180) from an open state to a close state or from the close state to the open state depending upon type of the micro-switch (180) being used.
Again referring to figures 1-6, working of the assembly (100) during the charging state and the discharging state of the mechanism springs (150) is described hereinafter. The mechanism springs (150) are generally charged with any one of an electrical motor (not shown) and the handle. The handle when used makes the pawl (60) to get engaged and disengaged with the ratchets (20, 40) during each operation/stroke. The rotation of the ratchets (20, 40) causes rotation of the charging shaft causing the plurality of mechanical linkages connected thereto to rotate thereby making the mechanism springs (150) to get compressed on each charging stroke of the handle. With number of charging strokes of the handle, the mechanism springs (150) get completely compressed/ charged.

During the charging stroke of the handle, the pawl (60) rotates to disengage from the ratchets (20, 40). At end of each charging stroke, the pawl (60) gets locked/ latched against successive tooth of the ratchets (20, 40) and rests in a gap (not numbered) between two teeth of the ratchets (20, 40).

After end of last charging stroke of the handle when the mechanism springs are completely charged, the pawl (60) becomes free and rests on the last tooth (10A', 30A') of the ratchets (20, 40). As the last tooth (10A', 30A') has more height as compared to other teeth of ratchet (20, 40), when the pawl (60) rests on the last tooth (10A', 30A'), the pawl (60) undergoes more angular rotation as compared to previous charging strokes. This excess rotation facilitates the protrusion (44) of the pawl (60) to press the first link (68) of the rotary component (80) through more distance causing the rotary component (80) to undergo more anticlockwise rotation as compared to previous charging strokes. Thus, the second link (72) of the rotary component (80) which has already pressed the micro-switch (180) throughout all previous charging strokes gets further rotated in the anticlockwise direction and releases the micro-switch (180) actuation causing the micro-switch (180) to change its state as the second link (72) moves away. Thus, the micro-switch (180) after the last charging stroke changes to the closed state from the open state or to the open state from the closed state depending upon type of the micro-switch (180) is getting used. This changed state of the micro-switch (180) provides the electrical indication that the mechanism springs (150) is charged.

Though the protrusion (44) of the pawl (60) rotates the rotary component (80) through a certain angle, the second link (72) which keeps the micro-switch (180) pressed does not leave contact with the micro-switch (180) and keeps the micro-switch (180) pressed by virtue of longer length. Thus, the state of micro-switch (180) remains same till the last charging stroke occurs.

The compressed mechanism springs (150) releases stored energy to get expanded and relaxed. This facilitates rotation of the charging shaft that in turn rotates the pawl (60) and the ratchets (20, 40) thereby causing the rotary component (80) to rotate back to the original position resulting in pressing of the micro-switch (180) by the second link (72). This gives indication that mechanism springs (150) are not charged.

Advantages of the invention

1. The assembly (100) provides the electrical indication for charging/discharging status of the mechanism springs (150).
2. The assembly (100) provides additional safety for an operator and facilitates development of further electrical logic.
3. The assembly (100) is a compact modular design that facilitates ease of assembly and requires minimum modifications in existing components.
4. The assembly (100) provides indication when the mechanism springs (150) are charged by the manual charging as well as by the electrical charging.
5. The assembly (100) is easily fitted on field/ sites and need not only be given as a factory fitted feature.

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, and 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. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.