FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the Invention. - SWITCH DISCONNECTOR MODULE FOR USE IN SWITCHING DEVICES
2. Applicant(s)
(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY: An Indian Company.
(c) ADDRESS: L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION
The present invention relates to switching devices. More particularly, the present invention relates to a Switch-Disconnector module for use in switching devices.
BACKGROUND AND THE PRIOR ART
The switches are required to isolate a load from supply, so that load side will be completely isolated to carry out any maintenance activity. Such switches are combination of number of electrical poles driven by a mechanism. For the ease of assembly, to carryout maintenance activity of any specific pole or to have choice of offering switch with required number of electrical pole; the electrical pole should be of modular construction and connected side by side.
The basic functionality of electrical pole is to carry, make and break rated current to withstand fault current and to make-break inrush current. To achieve this, electrical pole consist of contact system and arc quenching system. These systems need to be properly placed and enclosed inside the cover to perform their functionality.
Generally pole has been designed with two different covers which meet with each other to enclose contact system and arc quenching system; so two different tools will be required to manufacture two housings. When different switches needs to be offered for different current rating, the size of the electrical pole has to be different, which requires covers of different size.
US6239398 related to cassette construction of circuit breaker. It shows how terminals, rotor assembly and arc chute assembly get placed inside housing covers. It do not use identical housing covers to form a cassette and uses protrusion from one housing and recess from other housing to get fix in each other. Further it does not use any pressure plate to channelize gases.

US7116194 discloses electrical pole for low voltage circuit breaker; the invention is related .to cassette construction of circuit breaker. It shows how terminals, rotor assembly and arc chute assembly get placed inside housing covers. It do not use identical housing covers to form a cassette and uses protrusion from one housing and hollow pins from other housing to get fix in each other. Further it do not use any pressure plate to channelize gases, our invention uses pressure plate to channelize gases.
The disadvantages of the above mentioned prior art is that the number of tools required to offer switch of different rating increases which adds tooling cost and product cost.
Further two identical covers needs to be design to enclose contact system and arc quenching system, so that number of tool required will be lesser and it will also help in production by reduction in variety.
Thus there is a need to design the poles in such a way that, there has to be proper isolation between adjacent poles so that ionized gases generated during make-break will not pass from one pole to other. Also gases will not come outside cover. Also Contact system and arc quenching system should not be able to place in different orientation, to retain its functionality and to avoid adverse effect on electrical system.
OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.
Another object is to provide a cassette construction of Switch-Disconnector in switching devices having modular construction and identical housing covers to reduce tool investment production efforts.

Another object of the present invention is to provide a cassette construction of Switch-Disconnector in switching devices having firm fixing of contact system and arc quenching system inside pole.
Another abject of the present invention is to provide cassette construction of Switch-Disconnector in switching devices having a contact system and arc quenching system that should not be able to assemble in different orientation.
Another abject of the present invention is to provide cassette construction of Switch-Disconnector in switching devices adapted for complete isolation between adjacent pole and ionized gases should not come outside pole except from venting area.
Yet another abject of the present invention is to provide cassette construction of Switch-Disconnector in switching devices where covers should firmly fix with each to prevent any unintentional disassembly during handling on assembly line.
These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
There is provided a switch disconnector module for use in switching devices.
According to one embodiment of the present invention, there is provided a switch disconnector module comprising a pair of housing means for holding different components; a venting means providing exhaust for gas generated; a contact system comprising a pair of terminals connected to load and supply, a leaf spring means giving pressure to said contacts and a magnetic cladding means for enhancing the electro-dynamic forces; an arc quenching system comprising an arc

chute assembly to quench the arc generated and a pressure plate to channelize gas generated towards said venting means; a rotor assembly making contact with said terminal for switching operation, said rotor assembly located inside a circular relief provided at center of said housing means; a pair of cylindrical means for holding said housing covers tightly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the appended drawings:
Figure 1 illustrates a switch disconnector module for use in switching devices.
Figure 2 illustrates inside view of switch disconnector module.
Figure 3 illustrates exploded view of switch disconnector module.
Figure 4 illustrates isometric view of Housing cover.
Figure 5 illustrates front view of Housing cover.
Figure 6 illustrates isometric view of arc chute assembly.
Figure 7 illustrates front view of Arc chute assembly.
Figure 8 illustrates isometric view of rotor assembly.
Figure 9 illustrates cross sectional view of pole.
Figure 10 illustrates fixing of identical housing covers.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Reference is first invited to Fig 1 where the switch disconnector module for use in switching devices is shown. It encloses contact system and arc quenching system. Fig. 2 shows all the components enclosed in identical housing cover.
Fig. 3 shows each components enclosed in the present invention separately. Arc chute assembly (8a and 8b), is placed in housing cover cavity (17 and 18).
Fig. 4 and 5 shows different features in housing cover to accommodate different components. Identical housing is used for enclosing all the components, all the features in the housing are symmetrical with respect to horizontal as well as vertical plane passing through center of housing cover. To avoid that recess (26) has been provided on boundary wall of left side of the cover and protrusion (25) has been provided on boundary wall of right side of housing cover.
Fig. 6 and 7 shows arc chute assembly. It shows de ion plates stacked in arc chute assembly.
Fig. 8 shows circular notch present in a rotor. Rotor assembly (2) rotates and makes contact with terminal (7a and 7b) to make switch ON and OFF.
Fig. 9 shows cross sectional view of the pole.

Fig. 10 shows the module in which the cylinder passes through holes 12 and 13 of one cover and enters and get press fitted into holes 14 and 11 of another rotor respectively. This ensures complete assembly of Electrical pole.
The invented system is thus a switch disconnector module for use in switching devices
DETAILED DESCRIPTION OF THE INVENTION
Accordingly in the present invention switch disconnector module for use in switching devices is provided.
Following are the terminologies used in the present invention:-
Switch: Is an assembly of mechanism and contact system which isolates load from supply.
Cassette: Assembly of two identical housing which holds rotor assembly, terminal from supply
and load side.
Mechanism: This operates rotor assembly to make switch ON/OFF.
Termination pitch: Distance between termination holes of adjacent pole.
Pole pith: Distance between contact surfaces of adjacent pole.
End Surface: Is a surface of a rotor; which have male feature to engage with other component.
Electrical Pole: Every cassette forms a single Electrical pole.
Following are the components used in the present invention-Housing (1): Is a plastic component, which holds rotor assembly and terminal Rotor assembly (2): Assembly of rotor, moving contact, cladding and leaf-spring Rotor (3): Is a plastic component which holds pair of moving contact, cladding, leaf-spring

Moving contact (4): Is a copper component which makes and breaks with terminals (Connected to supply and load) to Make switch ON and OFF respectively.
Magnetic cladding (5): Is a C shape steel component used for enhancing the electrodynamic forces generated due to specific profile & arrangement of moving and fixed contacts.
Leaf spring (6): Is a steel component which gives pressure to contacts .
Terminal (7a & 7b): Is a copper component, which is connected to load and supply.
Arc chute assembly (8a & 8b): Is a assembly of de-ion plates and support, it is used to quench
the arc generated during make break operation.
Pressure plate (9a & 9b): Is a plastic component which is used to channelize the gases generated
during making break operation.
Cylinder (10a & 10b): is a plastic component which is used to hold two housing covers tightly.
Switch-Disconnector has capability to withstand fault current, to make & break inrush current and to carry, make, break rated operational current. Switch-Disconnector is combination of contact system and mechanism.
Each switch disconnector forms an electrical pole. Electrical pole as shown in figure. 1 encloses contact system and arc quenching system which support contact system for make break operations. Contact system consists of current carrying part (terminal and moving contact), leaf spring and cladding. Arc quenching system consist of arc chute assembly (assembly of de-ion plates), pressure plate. All these components have been enclosed in identical housing cover as shown in figure 2. Figure 4 and figure 5 shows different features in housing cover to accommodate above mentioned components.
Identical housing is used for enclosing all the components, all the features in the housing are symmetrical with respect to horizontal as well as vertical plane passing through center of housing cover. Rotor assembly (2), which rotates and make contact with terminal(7a and 7b) to make switch ON and OFF, Hence it is located inside circular relief provided at the center of housing

cover (1). Rotor assembly rotation is restricted to desired angle by surfaces (19, 20) of housing cover.
Another current carrying part terminal (7a) which gets connected to load or supply, gets located at cavity (22) of cover, terminal (7b) which gets connected to supply or load, gets located at cavity (23) of housing cover. These cavities restrict the motion of the terminal in X and Y direction, wherein another cover which will fit from top will restrict the motion in Z direction. So these cavities ensure proper positioning of terminal.
Arc chute assembly is important part for make-break performance, its orientation helps to achieve current breaking capacity of switch. And its improper placement can cause restriction to rotor assembly to make with terminal. Also it has to be firmly fitted inside housing.
Arc chute assembly (8a and 8b), is placed in housing cover cavity (17 and 18). The shape of arc chute assembly bottom surface (figure 6 and figure7) is designed in such a way that, it can be placed inside cavity (17,18) in only one orientation. Also cavity restricts arc chute assemblies movement in X and Y direction. And another housing cover which will be placed from top will restrict its motion in Z direction. This will ensure its positioning and functioning.
During Make-Break performance, ionized gases gets created; these gases should not go outside housing (except venting area), else it will cause external flashover. To avoid that recess (26) has been provided on boundary wall of left side of the cover and protrusion (25) has been provided on boundary wall of right side of housing cover as shown in figure.4. So when two identical housing cover fits into each other, The recess (26) of one cover and protrusion (25) from other cover fits into each other and vice versa. This creates complete overlapping of housing. So no ionized gases can escape through unintentional area of electrical pole.

Also to channelize gases towards venting is requirement of switch, as it increases pressure which increase arc velocity and helps in interrupting the arc. Hence pressure plate (9a,9b) is places at cavity of (15,16) to channelize the gases towards venting.
Creepage distance between adjacent pole has been increased by giving circular projection (21) inside housing cover and by giving circular notch (24) on rotor, its fitment has been shown in cross section view in figure.9; which increases isolation between adjacent poles and restricts direct access to internal gases, which avoids internal flashover.
The electric pole is finally assembled and tightly holds by cylinder (10a, 10b). Which passes through hole 12 and 13 of one cover and enters and get press fitted into hole 14 and 11 of another rotor respectively. This ensures complete assembly of Electrical pole. Such electrical poles gets engage with number of other poles and with mechanism to form a switch.
Advantages
• Modular construction
• Identical housing covers to reduce tool investment
• Firm fixing of contact system and arc quenching system inside pole
• Contact system and arc quenching system should not be able to assemble in different orientation
• Complete isolation between adjacent pole
• Ionized gases should not come outside pole except from venting area
• Covers should firmly fix with each to prevent any unintentional disassembly during handling on assembly line

Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications. However, all such modifications are deemed to be within the scope of the claims.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

WE CLAIM
1. A switch disconnector for use in switching devices comprising:
a pair of substantially identical housing means for holding different components;
a venting means providing exhaust for gas generated;
a contact system comprising a pair of terminals connected to load and supply, a leaf spring means giving pressure to said contacts and a magnetic cladding means for enhancing the electro-dynamic forces;
an arc quenching system comprising an arc chute assembly to quench the arc generated and a pressure plate to channelize gas generated towards said venting means;
a rotor assembly making contact with said terminal for switching operation, said rotor assembly located inside a circular relief provided at center of said housing means;
a pair of cylindrical means for holding said housing covers tightly.
2. Switch disconnector as claimed in claim 1 wherein said magnetic cladding means is substantially C shaped.
3. Switch disconnector as claimed in claim 1 wherein said arc chute assembly further comprising a plurality of plates and support.
4. Switch disconnector as claimed in claim 3 wherein said plates are substantially de ion plates.

5. Switch disconnector as claimed in claim 1 wherein said pair of housing means is substantially identical.
6. Switch disconnector as claimed in claim 1 wherein rotation of said rotor assembly is restricted to desired angle by housing cover.
7. Switch disconnector as claimed in claim 1 further comprising a plurality of cavities restricting motion of said terminal.
8. Switch disconnector as claimed in claim 1 forming a single electrical pole.
9. Switch disconnector as claimed in claim 1 wherein said housing cover having a substantially circular projection and said rotor having a substantially circular notch to increase isolation between adjacent poles.
10. A switch disconnector for use in switching devices as herein described and illustrated with reference to the accompanying drawings.