Claims:We Claim:

1. A charging handle (100) for a switching mechanism (110) of a circuit breaker comprising:
a main handle link (30) having a first end (10) and a second end (20), the first end (10) being structured to be coupled to the switching mechanism (110);
a connector link (60) having a first joint (40) and a second joint (50) being configured thereon, the first joint (40) being connected with the second end (20) of the main handle link (30); and
an arm rest link (90) being configured in a telescopic arrangement with the main handle link (30) using the second joint (50), the arm rest link (90) being movable in an anticlockwise direction so that a surface of the arm rest link (90) slides over the connector link (60),
wherein, the arm rest link (90) rotates from a first position (70) to a second position (75) using the first joint (40) of the connector link (50) and then pulls to a third position (80), thereby producing marginal increase in a moment arm due to the telescopic arrangement of the arm rest link (90) for charging the switching mechanism (110) with reduced human effort.

2. The charging handle (100) for the switching mechanism (110) of the circuit breaker as claimed in claim 1, wherein the first joint (40) and the second joint (50) are stopper pivot joints.

3. The charging handle (100) for the switching mechanism (110) of the circuit breaker as claimed in claim 1, wherein the charging handle (100) is used for storing energy in compression springs of the switching mechanism (110).

4. The charging handle (100) for the switching mechanism (110) of the circuit breaker as claimed in claim 1, wherein the charging handle (100) restores the first position (70) due to interlocking between the main handle link (30), the connector link (60) and the arm rest link (90) after completing charging strokes.

, Description:CHARGING HANDLE FOR SWITCHING MECHANISM OF CIRCUIT BREAKER

Field of the invention:

The invention relates generally to a field of protection devices such as circuit breakers, and more particularly, to a charging handle for a switching mechanism of the circuit breakers.

Background of the invention:

Circuit breaker is used in electrical transmission and distribution to carry, make and break current in various applications. An operating mechanism of the circuit breaker permits the circuit breaker to store energy by compressing springs that are linked to a contact assembly of the circuit breaker by latching different linkages. The stored energy of the springs and latching between the linkages allows the circuit breaker to make the contacts, hence completing an electrical circuit (closing of the circuit breaker) and break the contacts, hence interrupting the electrical circuit (tripping of the circuit breaker). Switchgear mechanisms use a handle to manually charge the compression springs in order to provide storage of the spring energy and achieving its intended motion of making the circuit breaker on.

Following are drawbacks observed in existing prior art technologies:

1. Most switchgear manufacturers provide a single entity handle to operate loaded ratchet and pawl assembly in charging system.
2. The charging handle used in a system has fixed arm length for charging.
3. Most switchgear manufacturers provide a telescopic rail for racking handle in a cradle, but due to space constraints it is not common for mechanism charging.

Accordingly, there is need to provide a charging handle for a switching mechanism of a circuit breaker that overcomes above mentioned drawbacks in the prior art.

Objects of the invention:

An object of the present invention is to provide ergonomically operated handle to charge a switching mechanism of a circuit breaker.

Another object of the present invention is to reduce mechanical effort of an end user to operate the switching mechanism of the circuit breaker.

Summary of the invention:

Accordingly, the present invention provides a charging handle for a switching mechanism of a circuit breaker. The charging handle comprises a main handle link, a connector link and an arm rest link. The main handle link includes a first end and a second end. The first end is structured to be coupled to the switching mechanism. The connector link includes a first joint and a second joint configured thereon. Specifically, the first joint and the second joint are stopper pivot joints. The first joint is connected with the second end of the main handle link. The arm rest link is configured in a telescopic arrangement with the main handle link using the second joint. The arm rest link is movable in an anticlockwise direction so that a surface of the arm rest link slides over the connector link.

In an operation, the arm rest link rotates from a first position to a second position using the first joint of the connector link. Thereafter, the arm rest link pulls to a third position, thereby producing marginal increase in a moment arm due to the telescopic arrangement of the arm rest link. Hence, the charging of the switching mechanism is carried out with reduced human effort. The charging handle restores the first position due to interlocking between the main handle link, the connector link and the arm rest link after completing charging strokes.

Brief description of the drawings:

Figure 1 shows a first position of a charging handle for a switching mechanism of a circuit breaker, in accordance with the present invention;

Figure 2 shows a second position of the charging handle of the figure 1;

Figure 3 shows a third position of the charging handle of the figure 1; and

Figure 4 shows the charging handle of the figure 1 mounted on the circuit breaker.

Detailed description of the embodiments:

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 charging handle for a switching mechanism of a circuit breaker. The charging handle is provided with a telescopic arrangement to allow ergonomically distribution of load required for charging the switching mechanism. The charging handle reduces human effort.

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 to 4, a charging handle (100) for a switching mechanism (110) of a circuit breaker (not numbered), in accordance with the present invention is shown. The charging handle (100) comprises a main handle link (30), a connector link (60) and an arm rest link (90).

The main handle link (30) includes a first end (10) and a second end (20). The first end (10) is structured to be coupled to the switching mechanism (110). The connector link (60) includes a first joint (40) and a second joint (50) being configured thereon. In an embodiment, the first joint (40) and the second joint (50) are stopper pivot joints. The first joint (40) is connected with the second end (20) of the main handle link (30). The arm rest link (90) is configured in a telescopic arrangement with the main handle link (30) using the second joint (50) of the connector link (60). The arm rest link (90) is movable in an anticlockwise direction so that a surface of the arm rest link (90) slides over the connector link (60).

Again referring to figures 1 to 4, in an operation, the charging handle (100) is used for charging the switching mechanism (110) of the circuit breaker. In an embodiment, the charging handle (100) is used for storing energy in compression springs (not shown) of the switching mechanism (110). The arm rest link (90) rotates from a first position (70) to a second position (75) using the first joint (40) of the connector link (50). Thereafter, the arm rest link (90) pulls to a third position (80). Due to the telescopic arrangement of the arm rest link (90), marginal increase in a moment arm produces for charging the switching mechanism (110) with reduced human effort. After completing charging, the charging handle (100) restores the first position (70) due to interlocking between the main handle link (30), the connector link (60) and the arm rest link (90).

Advantages of the invention:

1. The charging handle (100) includes compact design with telescopic arrangement to deliver more force with lesser effort.
2. The telescopic arrangement with rotation of the arm rest link (90) allows changing the position of the charging handle (100), thereby enhancing ergonomically promising solution to a charging system of the switching mechanism (110).
3. Mechanical advantage is increased during operation of charging, thereby delivering efficient torque.
4. Improvement of mechanical advantage in the charging handle (100) helps in reducing human effort to deliver a torque to the charging system.
5. After extension, the main handle link (30), the connector link (60) and the arm rest link (90) act as single rigid link.
6. Less space is required to accommodate the telescopic arrangement of the charging handle (100).
7. The charging handle (100) includes less moving parts that leads to better mechanical life and more strength of the charging system.

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.