DESC:FIELD OF THE INVENTION
The present invention relates generally to a contactor device used for switching an electrical circuit on or off. More particularly, the present invention relates to contactor device which is used in electrical applications to switch on/off a load having a housing of modular construction.

BACKGROUND ART
A contactor is an electrical device which is used for switching an electrical circuit on or off. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling motor switch of higher voltage, for example 230V. Contactors are most commonly used for controlling electric motors, electrical appliances and any electrical loads.

A contactor is considered to be a special type of power relay. However, the basic difference between the relay and contactor is that the contactor is used in applications with higher switching current carrying capacity, whereas the relay is used for lower current/resistive load applications. Contactors can be field mounted easily and are compact in size. Generally, these electrical devices feature multiple contacts. These contacts are in most cases normally open/close and provide operating power to the load when the contactor coil is energized. There are various types of contactors, and each type has its own set of features, capabilities, and applications. Contactors can break current over a wide range of loads, from a few amperes to thousands of amperes, and voltages from low voltage to thousands of volts in both AC & DC.

The contactor essentially consists a Housing, Contact assemblies, Coil and Electromagnet. The housing which houses the coil, electromagnets and contact assemblies provides insulation and protection from personnel touching the contacts. The housing which is the protective enclosure is made from different materials, such as polycarbonate, polyester, Nylon 6 and thermosetting plastic (Bakelite).

Contact assembly includes a pair of stationary contacts with moving contacts and it has multiple arrangement. One stationary contact will be a line side contact and the other stationary contact will be a load side contact. The moving contact assemblies are controlled by Coil and Electromagnet. Upon giving supply and on energizing the coil, electromagnet move the moveable contacts to form a bridge between the stationary contacts. When the moveable contacts are engaged with both stationary contacts, current is allowed to travel from the power source or line to the load or electrical device. If no power to the coil then the moveable contact is separated from the stationary contacts, an open circuit is created and the line and load are electrically isolated from one another.

Each contact assembly, and each set of moveable and stationary contacts thereof, corresponds to a pole or phase. Thus, in some contactors, the multiple of moveable contacts are all moved between open and closed positions in unison.

Depending upon the end use needs 2 pole, 3 pole or 4 pole contactors will be used. In the prior art for the manufacture of 2 Pole, 3 Pole and 4 Pole applications different housings according to the number of poles are used. It is essential to use the respective housing for contactors of different poles and cannot be interchanged since each housing is designed to accommodate the number of contact assemblies and other associated child parts. The selection of poles depends upon on hourse power of the motor on whether it is used in single phase or three phase.

The electrical contactors essentially comprises a housing, contact assemblies and coil or electromagnet and a top cover. The housing is a single part molded from different materials, such as polycarbonate, polyester, Nylon 6, Bakelite and thermosetting plastics according to the end use application such as voltage and current. The housing which houses the coil or electromagnets and contact assemblies provides insulation and protection from personnel touching the contacts.

The contactor housing known in the art includes internal partitions for separating an operator section from contact sections, and for isolating pole sections from one another. The partitions are contiguous with one another and with side walls of the housing, inhibiting flow of electric sparks within the housing.

The contact assembly slots formed in between the walls of the houses are also known as the poles. The number contact assembly slots present in the housing depends upon the number of poles of the contractor. This necessities different housing for the manufacture of contactors suitable to different pole applications

Since the housings are molded using plastic material such as polycarbonate, polyester, Nylon 6 and thermosetting plastics, it is essential to have different molding tools and for each number of poles new set of tooling is required. When number of poles increases, the tool size becomes huge and investment for tooling also becomes high. Since different housings are used for each number of poles, inventory cost of housings is high as well as needs large storage.

So it will be advantageous to provide a contactor which will be free from the problem of requirement of different contactor housing for the construction of contactors for different pole sizes.
OBJECT OF THE INVENTION
Accordingly, it is an object of the present invention to provide a modular housing for an electrical contactor that overcomes prior art problem of requirement of different contactor housing for the construction of contactors for different pole sizes.
It is main objective of the invention to provide a modular housing for an electrical contactor that uses the same components for the construction of contactors suitable for different pole sizes.

It is another objective of the invention to provide a modular housing for an electrical contactor that is cost effective.

It is another objective of the invention is to reduce the tool size, process cost (if the housing is big, you need higher tonnage of moulding machines) and tool cost.

It is another objective of the invention to provide a modular housing for an electrical contactor that minimizes the inventory of contactor housing of different sizes.

It is another objective of the invention to provide a modular housing for an electrical contactor that minimizes the storage space by eliminating the need of different contactor housings required for different pole sizes and by using parts that are compact in size.

It is another object of the invention to provide a modular housing that facilitates ease of replacement of the broken portion alone at the user end instead of the need of replacing the whole housing which helps the user to pay less amount of rework cost.

SUMMARY OF THE INVENTION
Thus according to the embodiment of the present invention there is provided a modular housing for an electrical contactor (EC) comprising first wall, second wall, intermediate walls, one or more clamping bolts and one or more threaded socket.

It is another aspect of the present invention, wherein the intermediate walls are sandwiched by the first wall and second wall and interconnected by one or more clamping bolts and one or more threaded socket forming a housing (H).

It is another aspect of the present invention, wherein the numbers of intermediate walls are selected according to the pole requirement of the electrical contactor (EC).

It is another aspect of the present invention, wherein first side wall, the second side wall and the intermediate walls are provided with at least two passage openings to accommodate one or more clamping bolts and fitted with one or more threaded socket.

It is another aspect of the present invention, wherein the first wall and second wall are same part, interchanged and used in both ends.

It is another aspect of the present invention, wherein first side wall, the second side wall and the intermediate walls are made of molding process using engineering plastic material such as polycarbonate, polyester, Nylon 6 and Bakelite.

BREIF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates a 2 pole electrical contactor as in the existing art.
Figure 2 illustrates a 3 pole electrical contactor as in the existing art.
Figure 3 illustrates a 4 pole electrical contactor as in the existing art.
Figure 4 schematically illustrates the assembled view of the 2 pole modular housing for an electrical contactor according to the present invention.
Figure 5 schematically illustrates the exploded view of the 2 pole modular housing for an electrical contactor according to the present invention.
Figure 6 schematically illustrates the assembled view of the 3 pole modular housing for an electrical contactor according to the present invention.
Figure 7 schematically illustrates the exploded view of the 3 pole modular housing for an electrical contactor according to the present invention.
Figure 8 schematically illustrates the assembled view of the 4 pole modular housing for an electrical contactor according to the present invention.
Figure 9 schematically illustrates the exploded view of the 4 pole modular housing for an electrical contactor according to the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS
The present invention provides a modular housing for an electrical contactor that eliminates the need of different contactor housings required for different pole sizes in the prior art.

In general, the electrical contactor shown in figure 1 to 3 comprises a housing (H) contact assemblies (C) and coil or electromagnet and a top cover (TC). The housing (H) is a single part molded from different materials, such as polycarbonate, polyester, Nylon 6, Bakelite and thermosetting plastics according to the end use application such as voltage and current. The housing which houses the coil or electromagnets and contact assemblies provides insulation and protection from personnel touching the contacts (known as finger proof type contacts).

The contactor housing known in the art includes internal partitions for separating an operator section from contact sections, and for isolating pole sections from one another. The partitions are contiguous with one another and with side walls of the housing, inhibiting flow of electric sparks within the housing.

The contact assembly slots formed between the walls houses the contact assemblies which are also known as the poles. The number contact assembly slots present in the housing depends upon the number of poles of the contractor. This necessities different housing (H) for the manufacture of contactors suitable to different pole applications as illustrated in figures 1,2 and 3.

As shown in figures 4, 5 and 6, the modular housing for contactor according to the present invention has a first side wall (1), a second side wall (2) and one or more intermediate walls (3). The first wall (1) and second side wall (2) are same part interchanged and used in both ends. The first side wall (1), the second side wall (2) and the intermediate walls (3) are provided with at least two passage openings. The passage opening are arranged such that the first side wall (1), the second side wall (2) and the intermediate walls (3) can be connected together using clamping bolts (4) and threaded sockets (5).

According to the requirement the predetermined numbers of intermediate walls (3) are arranged between the first side wall (1) and the second side wall (2) and are jointed together by clamping bolts (4) and threaded sockets (5).

A modular housing for 2 pole contactor as shown in figure 4 is provided with one number intermediate wall (3) which is arranged between the first side wall (1) and the second side wall (2) to accommodate two numbers contact assembly (C). The first side wall (1), the second side wall (2) and the intermediate wall (3) are retained as a single part using two numbers clamping bolts (4) and threaded sockets (5).

A modular housing for 3 pole contactor as shown in figure 5 is provided with two number intermediate walls (3) which are arranged between the first side wall (1) and the second side wall (2) to accommodate three numbers of contact assembly (C). The first side wall (1), the second side wall (2) and the intermediate walls (3) are retained as a single part using two numbers clamping bolts (4) and threaded sockets (5).

A modular housing for 4 pole contactor as shown in figure 6 is provided with three numbers intermediate walls (3) which rearranged between the first side wall (1) and the second side wall (2) to accommodate four numbers of contact assembly (C). The first side wall (1) the second side wall (2) and the intermediate walls (3) are retained as a single part using two numbers clamping bolts (4) and threaded sockets (5).

The first side wall (1), the second side wall (2) and the intermediate walls (3) are made of molding process using engineering plastic material such as polycarbonate, polyester, Nylon 6 and Bakelite according to the end use application such as voltage and current.

The contact assemblies, coil or electromagnet and top covers are assembled in the housing as known in the art. Like the first side wall (1), the second side wall (2) and the intermediate walls (3), the contact assemblies and coil or electromagnet are common for contactors of different poles. However the top cover is different for contactors of different poles.
Although the invention has been described with reference to specific embodiments, these descriptions are not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the invention as set forth in the appended claims. It is therefore, contemplated that the claims will cover any such modifications or embodiments that fall within the true scope of the invention.
,CLAIMS:WE CLAIM:
1. A modular housing for an electrical contactor (EC) comprising:
a first wall (1);
a second wall (2);
one or more intermediate walls (3);
one or more clamping bolts (4); and
one or more threaded socket (5),
wherein the intermediate walls (3) are sandwiched by the first wall (1) and second wall (2) and interconnected by one or more clamping bolts (4) and one or more threaded socket (5) forming a housing (H), and
wherein the number of intermediate walls (3) are selected according to the pole requirement of the electrical contactor (EC).

2. The modular housing for an electrical contactor (EC) as claimed in claim 1, wherein first side wall (1), the second side wall (2) and the intermediate walls (3) are provided with at least two passage openings to accommodate one or more clamping bolts (4) and fitted with one or more threaded socket (5).

3. The modular housing for an electrical contactor (EC) as claimed in claim 1, wherein the first wall (1) and second wall (2) are same part, interchanged and used in both ends.

4. The modular housing for an electrical contactor (EC) as claimed in claim 1, wherein first side wall (1), the second side wall (2) and the intermediate walls (3) are made of molding process using engineering plastic material such as polycarbonate, polyester, Nylon 6 and Bakelite.