FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
OPTIMIZED PLUG-IN CONTACT SYSTEM;
LARSEN & TOUBRO LIMITED, A COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956, WHOSE ADDRESS IS L&T HOUSE, BALLARD ESTATE, MUMBAI- 400 001, MAHARASHTRA, INDIA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

Field of the Invention
The invention relates generally to low voltage circuit breakers, and more particularly to, MCCB (Moulded Case Circuit Breaker) for electrically connecting it to panel boards.
Background of the invention
In general the MCCB (moulded case circuit breaker) is the one which includes the circuit breaker and trip device get assembled in a mould case. MCCB designed for the circuit protection of low voltage distribution system and it automatically cut off electric power in case of overload and short circuit. Normally, the MCCB rated current up to 2500A and the trip current may be adjustable in larger ratings. It can be manually or electrically open and close the electric circuit. In MCCB have four types of breaking capacities economical type, standard type, high interrupting type and very high interrupting types.
Further in general, the MCCB (moulded case circuit breaker) exist as a plug in type circuit breaker which is electrically connected to panel boards. Initially, the plug in circuit breaker uses the removable contacts to connect the circuit breaker and the use of removable contacts provides an inexpensive approach to repairing damaged or defective circuit breakers, as opposed to

replacing an entire circuit breaker or disassembling the breaker or a portion of the breaker to replace a single contact.
One existing system of plug in kit has a plug in contacts arranged in a circular geometry for engagement with a round contact. Because these tulip-finger contacts are arranged to fit about a periphery of a round stud, the diameter of the circular periphery of the round stud needs to be increased for large number of contacts.
Presently used plug in kit concepts reduces the large number of contacts to some extent. Here to manufacture single contact system, additional and different jaws are required. Thus, one problem associated with the need for different jaws is that increases the manufacturing costs it requires the different tools. The existing design to manufacture contact system is omega jaw concept and the alpha jaw concept. Both the jaw concepts have the disadvantage of using more number of components for single contact system.
The omega jaw concept has twenty two components per contact system and alpha jaw concept has fourteen components per contact system. Further the alpha jaw and omega jaw design uses more than one tool to manufacture and it uses four contact jaws for per contact system. The manufacturing of contact system in omega jaw and alpha jaw concepts is very complex and the cost for manufacturing said contacts system is also high.
Therefore, there is a need in art to construct the contact system with less number of component and tools.

Summary of the Invention
An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.
Accordingly, an aspect of the present invention is a plug-in kit for a circuit breaker, comprising: a plurality of terminals for receiving current to the plug-in kit, and a plug in base having a first end and a second end, wherein the first end and the second end includes a plurality of contact system, wherein the contact system, comprising: a first contact jaw, a second contact jaw placed opposite to the first contact jaw thereby forming a slot for accepting a movable contact of the circuit breaker, a plurality of spring for bonding the first and second contact jaws in order to deliver the contact pressure and a connector positioned between first and second contact jaws in order to guide the movable contact of the circuit breaker.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
Brief description of the drawings
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the

following description taken in conjunction with the accompanying drawings in which:
Figure 1 shows the circuit breaker with plug in kit according to one embodiment of the present invention.
Figure 2 shows the projection of figure 1 where circuit breaker is plugged out from plug-in kit according to one embodiment of the present invention.
Figure 3 shows the rear side of the circuit breaker as shown in figure 1 and 2 according to one embodiment of the present invention.
Figure 4 shows the plug in kit according to one embodiment of the present invention.
Figure 5 shows the female contact system inside the plug in kit according to one embodiment of the present invention.
Figure 6 shows the exploded view of the female contact system of figure 5 according to one embodiment of the present invention.
Figure 7 shows the contact jaw of female contact system as shown in figure 5 and 6 according to one embodiment of the present invention.
Figure 8 and 9 shows the contact system in an engaged and disengaged position with the contact of a circuit breaker according to one embodiment of the present invention.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
Detail description of the Invention
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration

purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
Figure 1 shows the circuit breaker with plug in kit according to one embodiment of the present invention. The circuit breaker with plug in kit consists of male contacts (3) connected with the circuit breaker (2) and female contacts (6) fixed to the plug-in base (7). The plug-in kit including of plug in base, female contact systems, terminals and finger shield. The pfug in kit is connected to the panel board, where the terminals (11) of the plug-in kit (1) are bolted to the bus bars of the panel board. The major constraint for this type of contact is that these contacts have to engage and disengage frequently. In engaged condition it has to carry continuous rated current. The female contacts (6) fixed in the plug-in kit
(1) consist of two halves of contact jaw (8), one copper connector (9) and
terminal (11). The two halves of contact jaw (8) held in its position by two springs
(10). The female contact assemblies are fixed in the plug-in base (7).
The current from the bus-bar enters into the incoming terminal (11), which is bolted to the connector (9). From there the current divides into two and enters into the contact jaw (8). The contact pressure at this point is provided by the spring (10) at the terminal side. From there the current enters to the Male contact (3) and flows to the circuit breaker (2). The contact pressure at the Male contact (3) side is provided by spring (10) at the Male contact side.
The Male contact (3) is connected with the terminals of the circuit breaker
(2) by bolting at the rear side. The circuit breaker consists of safety lock (4) to
connect the plug in kit.

Figure 2 shows the projection of figure 1 where circuit breaker is plugged out from plug-in kit according to one embodiment of the present invention. As shown in the figure, the circuit breaker including male contacts (3) in plug out position. The plug in kit including female contacts, plug-in base (7) and terminal (7) associated with the plug-in base.
Figure 3 shows the rear side of the circuit breaker as shown in figure 1 and 2 according to one embodiment of the present invention. The circuit breaker (2) as shown in figure including male contacts (3) and a safety lock (4).
Figure 4 shows the plug in kit according to one embodiment of the present invention. The plug in kit comprises the plug in base, female contact systems, terminals and finger shield. The plug in kit is connected to the panel board, where the terminals (11) of the plug-in kit (1) are bolted to the bus bars of the panel board. The major constraint for this type of contact is that these contacts have to engage and disengage frequently. In engaged condition it has to carry continuous rated current. The female contacts (6) fixed in the plug-in kit (1) consist of two halves of contact jaw (8), one copper connector (9) and terminal (11). The two halves of contact jaw (8) held in its position by two springs (10). The female contact assemblies are fixed in the plug-in base (7). The plug-in base includes a finger shields for providing ingress protection.
Figure 5 shows the female contact system inside the plug in kit according to one embodiment of the present invention. The female contact system (6) having a terminal (11), one or more spring (10) and one or more contact jaw. The terminal is to allow the current flow from the bus-bar, where the terminal is

bolted to the connector (as shown in figure 1). Further, the contact jaw receives the current and divides, where the first divided current flows in the first contact jaw and the second divided current flows in the second contact jaw. The one or more spring in the female contact system provides contact pressure at the terminal side.
Figure 6 shows the exploded view of the female contact system of figure 5 according to one embodiment of the present invention. The contact system includes first contact jaw and a second contact jaw which is placed opposite to each other means for accommodating the plug in device (i.e. circuit breaker). The contact system includes one or more spring to bond the first and second contact jaws in order to deliver the contact pressure. The connector (e.g. copper) which is positioned between first and second contact jaws to receive the male contacts of the circuit breaker. The connector gets coupled to the terminal with the assist of bolts.
Figure 7 shows the contact jaw of female contact system as shown in figure 5 and 6 according to one embodiment of the present invention.
Figure 8 and 9 shows the contact system in an engaged and disengaged position with the contact of a circuit breaker according to one embodiment of the present invention. In an example operation, the contact system including a first contact jaw, a second contact jaw, where the second jaw is placed opposite to the first contact jaw in order to form a slot for accepting a movable contact of the circuit breaker. The contact system further including one or more spring for bonding the first and second contact jaws in order to deliver the contact

pressure. The first and second contact jaws are symmetrical halves in shape. Further, a connector is positioned between first and second contact jaws in order to guide the movable contact of the circuit breaker. The connector coupled with the terminal to receive current from the panel board. As shown in the figure 8 (i.e. at the disengaged position), the contact (male) of the circuit breaker is at a disengaged position with the contact system (female) of the plug-in kit. During the engagement between the plug-in kit and the circuit breaker, the contact system (female) of the plug-in kit allows the contact (male) of the circuit breaker as shown in figure 9.
Although the invention has been described in terms of preferred embodiment, it is not limited thereto. Those skilled in this technology can make various alterations and modifications without departing from the scope and spirit of the invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.
FIGS. 1-9 are merely representational and are not drawn to scale. Certain portions thereof may be exaggerated, while others may be minimized. FIGS. 1-9 illustrate various embodiments of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.

We Claim:
1. A plug-in kit for a circuit breaker, comprising;
a plurality of terminals for receiving current to the plug-in kit; and a plug-in base having a first end and a second end, wherein the first end and the second end includes a plurality of contact system, wherein the contact system, comprising
a first contact jaw;
a second contact jaw placed opposite to the first contact jaw thereby forming a slot for accepting a movable contact of the circuit breaker;
a plurality of spring for bonding the first and second contact jaws in order to deliver the contact pressure; and
a connector positioned between first and second contact jaws in order to guide the movable contact of the circuit breaker
2. The plug-in kit as claimed in claim 1, wherein the connector coupled with the terminal to receive current from the panel board.
3. The plug-in kit as claimed in claim 1, wherein the first and second contact jaws are symmetrical halves.
4. The plug-in kit as claimed in claim 1, wherein the plug-in base including a finger shields for providing ingress protection.

5. The plug-in kit as claimed in claim 1, wherein the contact of the plug-in kit is a female contacts and the contacts of the circuit breaker is a male contacts, and wherein the female contacts of the plug in kit allows the male contacts of the circuit breaker.
6. The plug-in kit as claimed in claim 1, wherein the projection in the connector and slot in the contact jaws provides sufficient grip to hold the contact jaws with connector.
7. The plug-in kit as claimed in claim 1, wherein the contact jaws shape is in such a way that, it itself holds the spring in position which avoids the use of any extra components for holding the springs.