FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
ROTARY POWER CONTACT MECHANISM FOR
SWITCHGEAR MODULES
APPLICANT: LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra
INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

A) TECHNICAL FIELD
[0001] The present invention generally relates to switchgear modules and particularly relates to a power contact mechanism for switchgear modules. The present invention more particularly relates to a rotary power contact mechanism for switchgear modules,
B) BACK GROUND OF THE INVENTION
[0002] Circuit breakers are the mechanical switching devices capable of making, carrying and breaking currents under normal circuit conditions and also under specified abnormal conditions. A circuit breaker basically consists of a pair of separable contacts and an interrupting medium. The function of the contacts is to conduct the electrical current when the breaker is closed and withstand the arcs while interrupting. Generally, the electrical contacts have a stationary part and a moving part. By bringing the moving contact to touch the stationary contact, an electric current flows and the breaker is closed. By driving the moving contact away from the stationary contact, an electric arc is developed and by quenching the electrical arc the flow of the electrical current is stopped and the breaker is kept open.
[0003] In the existing technique, a panel operator needs to manually open the doors of the switchgear module to bring the switchgear module from a service position to a test position before racking out the switchgear module. Further in the existing technique, there is no safety to the panel operator while operating the switchgear module as the panel operator manually opens the door of the switchgear module to bring the switchgear module from a service position to a test position.

[0004] Hence there is a need to provide a contact mechanism for switchgear modules which is adapted to bring the modules from a service position to a test position without opening a door of the module. There also exists a need to provide a rotary power contact mechanism which ensures safety of the panel operator.
[0005] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECT OF THE PRESENT INVENTION
[0006] The primary object of the present invention is to provide a rotary power contact mechanism for switchgear modules to bring the switchgear module from a service position to a test position without opening the door.
[0007] Another object of the present invention is to provide a rotary power contact mechanism for switchgear modules which are assembled easily.
[0008] Yet another object of the present invention is to provide a rotary power contact mechanism for switchgear modules with a rotary power contact assembly which is compact in design.
[0009] Yet another object of the present invention is to provide a c rotary power contact mechanism for switchgear modules arranged with molded power contacts having a low contact resistance.
[0010] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

D) SUMMARY OF THE INVENTION
[0011] The various embodiments of the present invention provide a rotary power contact mechanism for switchgear modules The rotary power contact mechanism for switchgear modules contact isolation mechanism includes an actuating rod, a rotating rod connected to the actuating rod through a link, a slider pin, a spring assembly connected to the slider pin, a rotating power contact assembly mounted on the rotating rod, a door, an incoming power contact, an outgoing power contact and a key. The actuating rod is pushed inside by operating the key to rotate the rotating rod and to exert a force on the spring assembly via the slider-pin to get the spring to a dead center position to bring the incoming power contact and the outgoing power contact to a service position or a test position.
[0012] According to one embodiment of the present invention, the rotary power contact mechanism for switchgear modules includes a chassis plate, an actuating rod support for supporting the actuating rod, a link, a first crank and a second crank.
[0013] According to one embodiment of the present invention, the rotary power contact assembly of the switchgear modules includes one or more copper fingers fixed in an insulating case.
[0014] According to one embodiment of the present invention, the one or more copper fingers in the rotary power contact assembly acts as a bridge between the incoming power contact and the outgoing power contact.

[0015] According to one embodiment of the present invention, the switchgear module is disconnected from the main power supply when the incoming power contact and the outgoing power contact are in the test position.
[0016] According to one embodiment of the present invention, the switchboard module controls an electrical power flow to an output device.
[0017] According to one embodiment of the present invention, the panel operator brings the incoming power contact and the outgoing power contact from a service position to a test position for maintenance or service
[0018] According to one embodiment of the present invention, the key is adapted to bring the incoming power contact and the outgoing power contact from a service position to a test position to ensure the maximum safety to the panel operator.
[0019] According to one embodiment of the present invention, the incoming power contact and the outgoing power contact are molded to each other and are adapted to make or break an electrical circuit according to the contact mechanism.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0021] FIG. 1 illustrates a perspective view of the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention.

[0022] FIG. 2 illustrates a top side view of the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention.
[0023] FIG. 3 illustrates a side perspective view of the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention.
[0024] FIG.4 illustrates a perspective view of the rotary contact assembly in the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention.
[0025] FIG.5 illustrates a side perspective view of the rotary power contact mechanism for switchgear modules, with the switchgear module in the test position, according to one embodiment of the present invention.
[0026] FIG.6 illustrates a perspective view of the rotary power contact
mechanism for switchgear modules, with the switchgear module in the service
position, according to one embodiment of the present invention,
[0027] Although the specific features of the present invention are shown in some
drawings and not in others. This is done for convenience only as each feature may be
combined with any or all of the other features in accordance with the present
invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0028] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to

practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0029] The various embodiments of the present invention provide a rotary power contact mechanism for switchgear modules. The rotary power contact mechanism includes an actuating rod, a rotating rod connected to the actuating rod through a link, a slider pin, a spring assembly connected to the slider pin, a rotary power contact assembly mounted on the rotating rod, a door, an incoming power contact, an outgoing power contact, and a key. The actuating rod is pushed inside due to the key operation which in turn rotates the rotating rod and exerts a force on the spring assembly via the slider-pin to get the spring to a dead center position. This in turn brings the incoming power contact and the outgoing power contact to a service position or a test position.
[0030] FIG. 1 illustrates a top side perspective view of the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention while FIG. 2 illustrates a top side view of the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention and FIG. 3 illustrates a side perspective view of the rotary power contact mechanism for switchgear modules, according to one embodiment of the present invention. With respect to the FIG,1, FJG,2 and FIG.3, the rotary power contact mechanism for switchgear modules includes a chassis plate 102, an actuating rod support 104, a spring assembly 106, a slider pin 108, a rotary power contact assembly 110, an outgoing power contact 112, an incoming power contact 202, a key 204, a rotating rod 206, an actuating rod 208, a link 302, a first crank 304 and a second crank 306.

[0031] The rotating rod 206 is connected to the actuating rod 208 through the link 302. The spring assembly 106 is connected to the slider pin 108 and the rotary power contact assembly 110 is mounted on the rotating rod 206. The actuating rod 208 is pushed inside the switchgear module by operating the key 204 which in turn rotates the rotating rod 206 and exerts a force on the spring assembly 106 via the slider-pin 108 until the spring is pressed to its dead center position. On reaching the dead center position, the rotating rod 206 is rotated by the stored spring energy to bring the incoming power contact 202 and the outgoing power contact 112 to a service position or a test position.
[0032] The switchboard module is used to control the flow electrical power to an output device. Further when the panel operator needs to bring the switchgear modules for maintenance purpose, then the panel operator operates the key 204 due to which the incoming power contact 202 and the outgoing power contact 112 are switched from the service position to the test position with the help of the rack-in rod without opening the door of the switchgear module.
[0033] The rotary power contact mechanism of the switchgear modules includes the rotary power contact assembly 110 that acts as the main moving part to perform the mechanism of bringing the switchgear modules from the service position to the test position. The rotary power contact assembly 110 includes the rotating contact that isolates the incoming power contact 202 and outgoing power contact 112 when rotated in a defined manner. Further the contact mechanism provides a double isolation to the switchgear module from the power supply as shown in FIG.3.
[0034] FIG.4 illustrates a perspective view of the rotary contact assembly in the switchgear module, according to one embodiment of the present invention. The rotary power contact assembly 110 includes one or more copper fingers fixed in an insulating case. The insulating case is then mounted on the rotating rod 206. Further

the one or more copper fingers in the rotary power contact assembly 110 acts as a bridge between the incoming power contact 202 and the outgoing power contact 112 as shown in FIG.4.
[0035] F1G.5 illustrates a perspective view of the switchgear module with the rotary power contact assembly in the test position, according to one embodiment of the present invention while FIG.6 illustrates a perspective view of the switchgear module with the rotary power contact assembly in the service position, according to , one embodiment of the present invention.
[0036] The actuating rod 208 is pushed inside the switchgear module by operating the key 204 due to which the link 302 connected to the actuating rod 208 rotates the first crank 304. The rotation of the first crank 304 in turn rotates the rotating rod 206 and exerts a force on the spring assembly 106 via the slider-pin 108 to get the spring to a dead center position. The panel operator applies the force until the spring is pressed to the dead center position. When the spring crosses its dead center, the stored spring energy operation ensures that the contact opening or closing speed is independent of manual force applied by the panel operator.
[0037] After crossing the dead center position, the spring force will make sure to bring the contacts in the service position. Further for changing the position of the contacts, the actuating rod 208 is pushed inside the modules and when the spring crosses the dead center, the rotating rod 206 is rotated by the stored spring energy to bring the module either in the test position or the service position as shown in FIG. 5 and FIG.6. The switchgear module is connected to the main power supply in the service position and the switchgear module is isolated from the main power supply in the test position.
G) ADVANTAGES OF THE INVENTION

[0038] The various embodiments of the present invention provide a rotary power contact mechanism to facilitate a double isolation from the power contacts and safety of the panel operator operating the switchgear module .Further the panel operator can bring the switchgear module from the service to the test position and vice versa using the rack-in rod without opening the door which in turn provides safety to the panel operator. The rotary power contact assembly in the present invention is assembled easily and is compact in design. Also the key provided in the mechanism provides for easy operation. The opening speed and closing speed of the power contacts is independent of the manual force applied.
[0039] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0040] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1. A rotary power contact mechanism for a switchgear module, the mechanism comprising : an actuating rod;
a link connected to the actuating rod; a rotating rod connected to the actuating rod; a slider pin;
a spring assembly connected to the slider pin; a rotary power contact assembly mounted on the rotating rod; a door;
an incoming power contact; an outgoing power contact; and a key;
Wherein the key is actuated to rotate the actuating rod to rotate the rotary power contact assembly to exert a force on the spring assembly to bring the spring assembly to a dead center position thereby bringing the incoming power contact and the outgoing power contact to at least one of a service position and a test position without opening the door of the switch gear module.
2. The mechanism according to claim 1, further comprises a chassis plate.

3. The mechanism according to claim 1, further comprises an actuating rod support for supporting the actuating rod.
4. The mechanism according to claim 1, further comprises a first crank and a second crank.

5. The mechanism according to claim 1, wherein the rotary power contact assembly comprises an insulating case.
6. The mechanism according to claim 5, wherein the insulating case is mounted on the rotating rod.
7. The mechanism according to claim 1, wherein the rotary power contact assembly comprises a plurality of copper fingers fixed in the insulating case.
8. The mechanism according to claim 7, wherein the plurality of copper fingers is adapted to connect the incoming power contact and the outgoing power contact.
9. The mechanism according to claim 1, wherein the rotation of the rotary power contact assembly disconnects the switch gear module from the main power supply

when the incoming contact and the outgoing power contact are in the test position.
10. The mechanism according to claim 1, wherein the incoming power contact and the outgoing power contact are molded to each other.