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 Guiding 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 Guiding in Circuit Breaker
Field of the invention
The present invention relates to circuit breakers, and more particularly, to a mechanism for arc guiding of 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 andlight 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 a mechanism for arc guiding 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 guiding in a circuit breaker. The mechanism comprises housing having fixed contacts and moving contacts configured therein. The opening of the fixed contacts and the moving contacts causes an arc to produce therebetween. The mechanism further includes an arc runner positioned within the housing for rapidly directing the arc into an arc chamber. Further, the mechanism includes a slot motor configured between the arc runner and a wall of the housing facing towards the fixed contact. The slot motor is being capable of fast separating the fixed contact and the moving contacts thereby providing a narrow guide to the arc and ensuring a fast movement of the arc to the 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 voltageand limit the peak fault current.

Brief description of the drawings
Figure 1 shows a miniature circuit breaker with mechanism for arc guiding, in accordance with the present invention; and
Figure 2 shows a slot motor of the mechanism 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 embodiment.
The present invention provides a mechanism for arc guiding for a circuit breaker. The mechanism is an improvement of short circuit performance of the circuit breaker.The mechanism reduces time of arc motion immediately after contact separation with the use of slot motorwhich further reduces total arc quenching time.
Referring now to figure 1 and 2, there is shown a mechanism (50) for arc guiding in a circuit breaker (100). The mechanism (50) includes housing (10).
The housing (10) includes fixed contacts (not numbered) and moving contacts (not numbered) configured therein. The opening of the fixed contacts and the moving contacts causes an arc to produce therebetween.

Further, the mechanism (50) includes an arc runner (20) positioned within the housing (10) for rapidly directing the arc current into arc chamber (not shown). Specifically; the arc is rapidly lengthened by means of the arc runner
and arc chamber and the resistance of the arc is increased by cooling, lengthening and splitting the arc.
Further, the mechanism (50) includes a slot motor (30) configured between the arc runner (20) and a wall (12) of the housing (10) facing towards the fixed contact as the arc travels from fixedcontact thus facing towards arc runner (20) side.Theslot motor (30) helps in fast separation of the fixed contact and the moving contact thereby providing a narrow guide to the arc and ensuring a fast movement of the arc to the arc chamber.
In a preferred embodiment, the slot motor (30) is rectangular in shape with slot (32) at corner thereof for proper fitment in the arc runner (20) region. Specifically, figure 2 shows the slot motor (30).
The slot motor (30) facing towards the fixed contact directs the arc towards the arc chute. The slot motor (30) restricts the arc movement into the narrow gap of the housing. Thus slot motor (30) directs the arc into arc chute not to other areas.
In an embodiment, the slot motor (30) has length = 17mm, width = 7.4 mm, thickness = 2 mm and made up of material cold rolled closely annealed (CRCA).
The arc received into the arc chamber 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.

Advantages of the invention
l.Construction, manufacturing and placing of slot motor of the mechanism [50]
is quite easy.
2.The slot motor use is a choice not a part of the circuit breaker.
3.The mechanism (50) can be used in any kind of low voltage circuit breakers
for rapid arc guiding.
4.The slot motor of the mechanism (50) has unique shape and configuration
which allows rapid movement of the arc.
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 guiding in a circuit breaker, the mechanism comprising:
housing comprising fixed contacts and moving contacts configured therein, wherein opening of the fixed contacts and the moving contacts causes an arc to produce therebetween;
anarc runner positioned within the housing for rapidly directing the arc into arc chamber; and
a slot motor configured between the arc runner and a wall of the housing facing towards the fixed contact, the slot motor being capable of fast separating the fixed contact and the moving contacts thereby providing a narrow guide to the arc and ensuring a fast movement of the arc to the arc chamber,
wherein the arc is split into number of series of arcs within the arc chamber thereby resulting in high voltage across the circuit breaker to counteract voltage and limit the peak fault current.
2. The mechanism as claimed in claim 1, wherein the slot motor is rectangle in shape with slot at corner thereof for proper fitment in the arc runner region.