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:
MODULAR INDICATOR ASSEMBLY FOR SWITCHBOARD
MODULE
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 an electrical switchboards and particularly to an electrical contact system in switchboard modules to operate the switchboard module from service position to a test position without opening the door of the switchboard module. More particularly the present invention relates to provide a modular indicator assembly to indicate the service and test position of the power contacts in the switchboard module.
B) BACKGROUND OF THE INVENTION
[0002] A typical electrical switchboard module is operated in three distinct positions namely service, test and isolated positions. In service position the module is fully inserted into the housing or module or circuit breaker compartment and the power and control contacts are fully made. In test position the power contacts are isolated but the control circuit is still connected. The test condition is essential to facilitate testing of the control circuits with functional interlocks, without energizing the connected load. In isolated position both the power and control circuits are isolated.
[0003] It is common practice to provide a test position for the switchboard modules to intermediate its engaged and disengaged positions, where the power connectors are separated but the auxiliary connectors are still engaged. In this test position, the accessorial functions can be thoroughly tested and hence provide safety factor for the panel operator while working on it. The operation of the withdrawal equipment, such as a breaker or components on a removable chassis, is not possible unless it is in test, isolated or totally removed positions.

[0004] In conventional switchboard modules the operator has to open the door of the switchboard module to know whether the power contacts are charged or not i.e. to know service and test position of the module. More over the assembling of the conventional indication system for switchboard module is very difficult and the indication system is costly. Hence there is a need to provide a reliable mechanism to indicate the position of switchboard module without opening the door of the module when the module is operated from service to test position. Further there is a need to ensure the safety of the panel operator while working on it.
C) OBJECTS OF THE INVENTION
[0005] The primary object of the present invention is to provide an electrical contact system with a modular indicator kit to indicate service and test position of the power contacts in the switchboard module and to ensure safety of the panel operator during maintenance or service process.
[0006] Yet another object of the present invention is to provide an electrical contact system with a modular indicator kit to determine the status of the switchboard module without opening the door of the switchboard module.
[0007] Yet another object of the present invention is to provide a modular ..indicator kit which is easy to assemble and cost effective.

[0008] 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
[0009] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
[0010] Various embodiments of the present invention provide a modular indicator assembly to indicate the status of electrical power contacts in the switchboard module when the module is operated from service position to test position without opening the door of the switchboard panel. The indicator assembly includes an indicator kit, connecting rod and rail assembly. The indicator kit includes a rotating mechanism to show the exact position of the power contacts in the switchboard module. The modular indicator assembly is easy to assemble and cost effective. It ensures safety of the panel operator during maintenance or service process.
[0011] According to one embodiment of the present invention, a modular indicator assembly for switchboard module including a chassis plate is provided with an indicator kit which is mounted on a chassis plate in a switchboard module. Indicator housing is provided in the indicator kit. A cylindrical dial is arranged inside the indicator housing. A slider is arranged movably inside cylindrical dial. A hook is provided on the slider. A front cap is attached to the indicator housing. A rear cap is attached to the indicator housing. A connecting rod is coupled to the slider. A rail assembly is coupled to the connecting rod.

[0012] The cylindrical dial is provided with a helical slot for engaging with the hook of the slider and engraved with pluralities of preset symbols to indicate an operating status of the switchboard module. The cylindrical dial is engraved with a symbol "S" to indicate a service position of the power contacts in the switchboard module. The cylindrical dial is engraved with a symbol "T" to indicate a test position of the power contacts in the switchboard module.
[0013] The front cap is provided with a display window to indicate the operating status of the power contacts in the switchboard module. The connecting rod is coupled to the slider through a female coupler. The rail assembly has a guide mounted with an inner rail. The connecting rod is attached to the inner rail through a male coupler. The inner rail of the rail assembly moves inside the guide which pushes the connecting rod attached to the inner rail in forward direction to push the slider in forward direction to rotate the cylindrical dial to start showing 'T' symbol in the display window, when the switchboard module is operated form service to test position.
[0014] According to one embodiment of the present invention, the indicator kit comprises indicator housing. A rotating mechanism is enclosed in the indicator housing. The rotating mechanism includes a cylindrical dial. The inner surface of the cylindrical dial includes a helical slot. A symbol 'S' and 'T' are engraved on the front face of the cylindrical dial to show service and test position respectively. The indicator kit includes a slider provided with a slider hook on its periphery. The rear end of the slider includes a coupler female. A freely rotated cylindrical dial is engaged with the slider's hook through its helical slot and is enclosed in the indicator housing. The rotating mechanism is enclosed in the indicator housing and is covered on both

ends by using a front cap and rear cap. The front cap includes a display window to display the service and test position and the rear cap includes a central circular hole.
[0015] According to one embodiment of the present invention, the connecting rod is provided which includes a male coupler towards one end and a female coupler towards other end. The male coupler of the connecting rod is connected to the female coupler of the slider in the indicator kit. The female coupler of the connecting rod is connected to the inner rail in the rail assembly. The rail assembly includes a guide which guides the inner rail when the power contacts in the switchboard module are isolated. When the power contacts in the switchboard module is in service position, the indicator kit shows 'S' symbol on the display window. As the power contacts are brought to test position, the inner rail of the rail assembly moves inside the guider, which pushes the connecting rod attached to the inner rail in forward direction. The slider is pushed forward by the connecting rod, which in turn rotates the cylindrical dial of indicator kit in the indicator housing and start showing 'T' though its display window. Once the module is brought to test position, the operator can safely do the maintenance or service operation.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0016] 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:
[0017] FIG. 1 shows a perspective view of an indicator kit according to an embodiment of the present invention.

[0018] FIG. 2 shows an exploded view of an indicator kit of FIG. 1.
[0019] FIG. 3 shows a top view of the electrical contact system in switchboard module with an indicator kit according to an embodiment of the present invention.
[0020] FIG. 4 shows a top perspective view of the electrical contact system in the switchboard module when the door of the switchboard module is in open condition.
F) DETAILED DESCRIPTION OF THE INVENTION
[0021] In the following detailed description, 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.
[0022] Various embodiments of the present invention provide a modular indicator assembly to indicate the position of the electrical contacts in the switchboard module. According to one embodiment of the present invention, a modular indicator assembly for switchboard module including a chassis plate is provided with an indicator kit which is mounted on a chassis plate in a switchboard module. Indicator housing is provided in the indicator kit. A cylindrical dial is arranged inside the indicator housing. A slider is arranged movably inside cylindrical dial. A hook is provided on the slider. A front cap is attached to the indicator housing. A rear cap is

attached to the indicator housing. A connecting rod is coupled to the slider. A rail assembly is coupled to the connecting rod.
[0023] The cylindrical dial is provided with a helical slot for engaging with the hook of the slider and engraved with pluralities of preset symbols to indicate an operating status of the switchboard module. The cylindrical dial is engraved with a symbol "S" to indicate a service position of the power contacts in the switchboard module. The cylindrical dial is engraved with a symbol "T" to indicate a test position of the power contacts in the switchboard module.
[0024] The front cap is provided with a display window to indicate the operating status of the poNMeT contacts in the switchboard moduie. The connecting rod i?> tempted to the slid?* though -& female coupler. The rail assembly has a guide mounted with an inner rail. The connecting rod is attached to the inner rail through a male coupler. The inner rail of the rail assembly moves inside the guide which pushes the connecting rod attached to the innef rail in forward direction to push the slider in forward direction to rotate the cylindrical dial to start showing 'T' symbol in the display window, when the switchboard module is operated form service to test position.
[0025] With respect to F1G.1, an indicator kit 20 is provided to indicate the service and test position of the power contacts in the switchboard module. The indicator assembly includes an indicator kit 20, connecting rod 30 and rail assembly 40. The indicator kit 20 is connected to one end of the connecting rod 30 and the other end of the connecting rod 30 is connected to the inner rail 41 of the rail assembly 40. The rail assembly 40 includes a guider 42 which guides the inner rail 41 when the power contacts in the switchboard module are isolated. When the switchboard module is operated from service to test position, the inner rail 41 of the rail assembly 40 moves

inside the guider 42, which in turn pushes the connecting rod 30 attached to the inner rail 41 in forward direction. The indicator kit 20 includes a rotating mechanism, which rotates to indicate the position of the power contacts in the switchboard module. The front cap 21 of the indicator kit 20 includes a display window 22 through which an operator can inspect whether the power contacts are in service or test position. The display window shows *S* symbol when the power contacts are in service position and shows 'T' symbol when the power contacts are in test position.
[0026] FIG. 2 is an exploded view of the indicator kit 20, according to an embodiment of the present invention. The indicator kit 20 includes rotating mechanisms which rotate to show the exact position of the power contacts in the switchboard module. The rotating mechanism includes a cylindrical dial 23. The symbol 'S' and T' are engraved on the front face of the cylindrical dial 23 to show service and test position respectively. The inner diameter of the cylindrical dial 23 includes a helical slot 24. The indicator kit 20 includes a cylindrical slider 26 provided with a slider hook 27 on its periphery as shown in FIG.2. The rear end of the slider 26 includes a coupler female 28. A freely rotated cylindrical dial 23 is engaged with the slider's hook 27 through its helical slot 24 and is enclosed in the indicator housing 25. The rotating mechanism is enclosed in the indicator housing and is covered on both ends by using a front cap 21 and rear cap 29 to obtain an indicator kit 10.
[0027] In an embodiment of the present invention a connecting rod 30 is provided which includes a male couple 31 towards one end and a female couple 32 towards other end. The male couple 31 of the connecting rod is connected to the female coupler 28 of the slider 26 in the indicator kit 20. The female coupler 28 of the connecting rod 30 is connected to the inner rail in

the rail assembly. When the power contacts in the switchboard module is in service position, the indicator kit 20 shows 'S' symbol on the display window 21. As the power contacts are brought to test position, the inner rail 41 of the rail assembly 40 moves inside the guider 42, which pushes the connecting rod 30 attached to the inner rail 41 in forward direction. The slider 26 is pushed forward by the connecting rod 30, which in turn rotates the cylindrical dial 23 of indicator kit 20 in the indicator housing 25 and start showing 'T' though its display window 21. Once the module is brought to test position, the operator can safely do the maintenance or service operation.
[0028] FIG. 3 shows a top view of the electrical contact system in switchboard module with an indicator kit according to an embodiment of the present invention. The electrical contact system is enclosed in the switchboard panel 56. In this position, the door 51 of the switchboard panel 56 is closed while the display window 21 on the front face of the indicator kit 20 is visible from outside. With respect to FIG. 3, the switchboard module is enclosed in the switchboard panel 56. The electrical contact system in the switchboard module 56 includes a fixed power contact and a dropper power contact mounted on the chassis plate 52. A guiding rail assembly 40 is fixed on the chassis plate 52 and includes a C type groove to receive the movable guides the power contacts 53.
[0029] When the racking handle 54 is rotated in anticlockwise direction, the isolating jaw contacts in the molded power contact kit is displaced away from the dropper power contact kits to disconnect the electrical power contacts in the switchboard module thereby moving the switchboard module to test position from the service position. In this position the inner rail 41 (Refer FIG.l) of the rail assembly 40 moves inside the guider 42, which pushes the connecting

rod 30 attached to the inner rail 41 in forward direction. The connecting rod 30 is attached to the slider of the indicator kit 20 which has a hook 27 (Refer FIG. 2) on its top. A freely rotated cylindrical dial is engaged with the slider's hook through its helical slot 23. As the power contacts are brought to test position, the slider is pushed forward by connecting rod 30, which in turn rotates the cylindrical dial of indicator kit 20 in the indicator housing 25 and start showing 'T though its display window 21. Whereas in service position, since the electrical contacts are in engaged position the inner rail 41 in the rail assembly is in its extreme end position hence there is no pressure on the connecting rod 30. As a result the indicator kit 20 in the indicator housing shows 'S' symbol on its display window.
[0030] FIG. 4 shows a top perspective view of the electrical contact system in the switchboard module when the door of the switchboard module is in open condition. It shows an indicator kit 20 mounted on the chassis plate 52 to indicate the service and test position of the power contacts in the switchboard module. The connecting rod 30 is connected to the indicator kit 30 as shown. Even when the door of the switchboard module is closed the front face of the indicator kit is visible from outside the switchboard panel 56. An operator can easily identify the position of the module without opening the door of the switchboard module. The switching device operating handle 55 and a racking handle 54 is provided to operate the switch device in ON and OFF condition.
G) ADVANTAGES OF THE INVENTION
[0031] Various embodiments of the present invention provide a modular indicator assembly to indicate the status of electrical power contacts in the switchboard module when the module is

operated from service position to test position. The indicator assembly includes an indicator kit, connecting rod and rail assembly. The indicator kit includes a rotating mechanism to show the exact position of the power contacts in the switchboard module without opening the door of the switchboard panel. The modular indicator assembly is easy W assemble and cost effective. It ensures safety of the panel operator during maintenance or service process.

CLAIMS
What is claimed is:
1. A modular indicator assembly for switchboard module including a chassis plate,
comprising:
An indicator kit mounted on a chassis plate in a switchboard module;
An indicator housing provided in the indicator kit;
A cylindrical dial arranged inside the indicator housing;
A slider arranged movably inside the cylindrical dial;
A hook provided on the slider;
A front cap attached to the indicator housing;
A rear cap attached to the indicator housing;
A connecting rod coupled to the slider;
A rail assembly coupled to the connecting rod;
Wherein the cylindrical dial is provided with a helical slot for engaging with the hook of
the slider and engraved with pluralities of preset symbols to indicate an operating status
of the switchboard module.
2. The assembly according to claim 1, wherein the cylindrical dial is engraved with a symbol "S" to indicate a service position of the power contacts in the switchboard module.
3. The assembly according to claim 1, wherein the cylindrical dial is engraved with a symbol "T" to indicate a test position of the power contacts in the switchboard module.

4. The assembly according to claim 1, wherein the from cap is provided with a display
window to indicate the operating status of the power contacts in the switchboard module.
5. The assembly according to claim 1, wherein the connecting rod is coupled to the slider through a female coupler.
6. The assembly according to claim 1, wherein the rail assembly has a guide mounted with an inner rail.
7. The assembly according to claim 1, wherein the connecting rod is attached to the inner rail through a male coupler.
8. The indicator assembly according to claim 1, wherein the inner rail of the rail assembly
moves inside the guide which pushes the connecting rod attached to the inner rail in
forward direction to push the slider in forward direction to rotate the cylindrical dial to
start showing 'T' symbol in the display window, when the switchboard module is
operated form service to test position.