FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION:
Mechanism for Arc Travelling in Circuit Breaker
2. APPLICANT:
(a) NAME: Larsen&Toubro Limited
(b) NATIONALITY: Indian Company registered under the
provisions of the Companies Act-1956.
(c) ADDRESS: LARSEN & TOUBRO LIMITED,
L&T House, Ballard Estate, P. 0. Box: 278, Mumbai 400 001, India
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Mechanism for Arc Travelling in Circuit Breaker
Field of the invention
The present invention relates to circuit breakers, and more particularly, to an mechanism for arc travelling a short circuit break arcs ignited between opening contacts of the circuit breaker.
Background of the invention
Miniature circuit breakers (MCB) are widely used to protect electrical facilities within commercial, domestic and light industrial buildings. The circuit breakers are current limiting devices commonly used with supply voltages 200 -250V ac and rated currents in the range of 6 - 63 A.
The MCBs give protection against overload and short circuit faults. It provides protection against short circuit faults of 103 - 104 A. During the short circuit faults, an electric arc is drawn between two opening contacts.
The arc produced by the opening of the contacts needs to be dissipated and extinguished. Furthermore, the arc debris must not be allowed to accumulate or otherwise interfere with the contacts or with operating mechanisms. The mechanisms currently available for arc quenching are effective but slow. The slow quenching of the arc may damage the opening contacts as well as operating mechanism of the circuit breaker.
Accordingly, there exists a need to provide an mechanism for arc travelling which overcomes abovementioned drawbacks.

Object of the invention
An object of the present invention is to reduce time of an arc quenching in the circuit breaker.
Another object of the present invention is to avoid damage to opening contacts and operating mechanism due to arc.
Summary of the invention
Accordingly, the present invention provides a mechanism for arc travelling in circuit breaker. The mechanism comprises housing having fixed contacts and moving contacts configured therein. Specifically, opening of the fixed contacts and the moving contacts causes an arc to produce therebetween. Further, the mechanism comprises an arc runner positioned within the housing for rapidly directing the arc into arc chamber. Furthermore, the mechanism comprises a U frame and a hammer component forming welding group along with the fixed contact and the arc runner. Characterized in that, the arc runner, the U frame, the hammer and a portion of the fixed contact are plated with nickel. The nickel plating allows faster movement of the arc towards arc chamber.
Further, the arc is split into number of series arcs within the arc chamber thereby resulting in high voltage across the circuit breaker to counteract voltage and limit the peak fault current.
Brief description of the drawings

Figure 1 shows an assembly of a circuit breaker device;
Figure 2 shows a hammer component of the circuit breaker device of figure 1;
Figure 3 shows an arc runner frame component of the circuit breaker device of figure 1;
Figure 4 shows a U frame component of the circuit breaker device of figure; and
Figure 5 shows partially plated fixed contact, in accordance with the present
invention.
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 embodiment.
The present invention provides a mechanism for arc travelling of a circuit
breaker. The mechanism is an improvement of short circuit performance of the
circuit breaker. The mechanism reduces time of the arc motion immediately after contact separation which further reduces total arc quenching time.
Referring to figures 1 to 5, there is shown a mechanism for arc travelling in circuit breaker (100). The mechanism is configured within housing (10) as

shown in figure 1. The housing [10] includes fixed contacts (12) and moving contacts (not numbered) configured therein. Opening of the fixed contacts and the moving contacts causes an arc to produce therebetween.
Further, the mechanism comprises an arc runner (20) as shown in figure 3, positioned within the housing (10) for rapidly directing the arc into arc chamber.
Further, the mechanism comprises a U frame (30) as shown in figure 4, and a hammer component (40) as shown in figure 2 forming a welding group along with the fixed contact (12) and the arc runner (20).
Characterized in that, the arc runner (20), the U frame (30), the hammer component (40) and a portion (12a) of the fixed contact (12) are plated with nickel. Portion (12a) of the fixed contact (12) plated with nickel is shown in figure 5. The nickel plating of the above-mentioned component allows faster-movement of the arc towards arc chamber (not numbered).
Within the arc chamber the arc is split into number of series arcs thereby resulting in high voltage across the circuit breaker (100) to counteract voltage and limit the peak fault current.
Nickel is electronegative material. When the arc runner (20), the U frame (30), the hammer component (40) and a portion (12a) of the fixed contact (12) are plated with nickel, nickel attracts the positive ion from arc and allows the fast movement of arc towards the arc chamber. Further, the nickel plated components also help in reducing the arc temperature and thus help in cooling the arc. Thus overall nickel plated components help in reducing the time of arc

travel between opening of the fixed contact (12) and the moving contacts to its movement up to arc chamber. The portion (12a) of the fixed contact (12) is responsible for current carrying in normal condition and nickel plating does not hamper the current carrying capacity thereof.
Thus, the faster arc movement with continued current carrying capacity is achieved. Further, the partial plating of portion (12a) of the fixed contact (12) helps in reducing the arc temperature and thus allows the fast arc extinction.
Further, the nickel plating of the arc runner (20), the U frame (30), the hammer component (40) and a portion (12a) of the fixed contact (12) has many other advantages such as excellent corrosion, rust resistance, wear resistance, surface hardness, lubricity, ductility and magnetic characteristics.
Advantages of the invention
1. The mechanism does not require extra components to improve arc
travelling.
2. The plating of the welding group components with nickel is simple.
3. The mechanism can be used in any kind of low voltage breaker for same
purpose
The foregoing object the invention is accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be

interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.

We Claim
1. A mechanism for arc travelling in circuit breaker, the mechanism comprising:
housing having fixed contacts and moving contacts configured therein, wherein opening of the fixed contacts and the moving contacts causes an arc to produce therebetween;
an arc runner positioned within the housing for rapidly directing the arc into arc chamber; and
a U frame and a hammer component forming welding group along with the fixed contact and the arc runner, characterized in that the arc runner, the U frame, the hammer and a portion of the fixed contact are plated with nickel, wherein nickel plating allows faster movement of the arc towards arc chamber,
wherein the arc is split into number of series arcs within the arc chamber thereby resulting in high voltage across the circuit breaker to counteract voltage and limit the peak fault current.