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:
POSITION INDICATION AND LOCKING MECHANISM FOR MODULES IN SWITCHBOARDS
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 the electrical switching devices and particularly to feeder modules in a switchboard assembly. The present invention more particularly relates to a position indication and locking mechanism for the modules in the switch board assembly.
B) BACKGROUND OF THE INVENTION
[0002] The electrical switching devices such as miniature circuit breakers, residual circuit breakers and isolators are used in domestic and industrial applications for protection against over currents. It is generally required to control the electrical power networks by switching a circuit "ON", by carrying load or by switching a circuit "OFF" under manual or automatic suspension. When an over current is passed through an electrical circuit, the contacts in the switching devices open or trip to block the current which is greater than the rating of the current device.
[0003] There are several provisions available to control the electrical contacts. In some cases it includes manual operation, where the moving contact is moved in conjunction with the fixed contact to open or close the electrical connection. In other cases, whenever the over current occurs in the power circuits, the circuit breakers trip automatically to break the contacts. The function of the circuit breakers is to maintain two stable conditions such as a closed condition and an open condition.
[0004] However in certain cases, the switching devices operate due to a fault. During the operation of the switching devices like miniature circuit breaker, residual current circuit breaker and isolator, there are chances that contact gets welded due to high currents and current still flows through the circuit even when

a knob of the device indicates that it is in "OFF" state. When someone comes in to a direct contact with circuit during a maintenance period, thinking that the breaker is in switched "OFF" condition, it may result in a serious shock and can be fatal. In some circumstances, the moving contact remains stuck on the fixed contact with an adhesive force such that the mechanism does not exert enough force to break the joint.
[0005] In some cases where the circuit breakers employed are relatively smaller in size and light in weight, the circuit breakers are provided with plug-in type primary disconnect contacts that do not require direct contact to effect their connection and disconnection with mating disconnect contacts of the switchboard. In these cases circuit breaker can be plugged in and unplugged from a Jive switchboard easily and safely.
[0006] For higher current applications, the circuit breakers used are large and quite heavy and so the movement of the circuit breaker to electrically connect and disconnect it from the switchboard is quite difficult. Due to an increase in the current ratings, the contact pressures of the primary disconnect contacts becomes extremely difficult to handle. Draw out apparatus are used to support such electrical device for racking movement between an extended position well out of an enclosure compartment and an engaged position within the compartment where the load current carrying the primary disconnect contacts of the device and enclosure are fully engaged. A test position is provided for the device between its engaged and extended positions where the primary contacts are separated but the secondary contacts are still engaged. In this test position, the accessorial functions can be thoroughly tested in safety while the device is "dead". Hence it is important to provide position indication mechanism to the operator in the draw out apparatus, so that operator can be aware of the position of the device relative to the enclosure for safety purposes.

[0007] Circuit breakers, both single and multi-phase circuit breakers, typically include a lever for manually operating the circuit breaker. Frequently, it is desirable that the lever be operated using a mechanical interface, such as a direct mount rotor mechanism having a handle that can be manually operated, wherein the handle mechanism is of the type that is directly mounted to the circuit breaker. During the operation, the handle mechanism moves the circuit breaker lever to various operative positions. The operative positions include a "connected" position, a "disconnected" position and a "test" position. In some instances, it is necessary to lock the handle mechanism in the disconnected position to safeguard personnel working on associated equipment.
[0008] However, when the electrical contacts of the circuit breaker are closely wei'ded, the locking of the handfe mechanism in the disconnected position woufd create dangerous and inappropriate effects especially during a short circuit condition.
[0009] In the currently available devices, an operator has to rotate the handle for several times such as 6-7 turns to reach a particular position of the module, like Connected, Test, Disconnected positions. This results in to a more energy and time consuming activities. Some time, there is a chance that an operator stops the rack-in or rack-out operation of a module and removes the handle from the module without reaching the correct position of the module, thereby resulting in an accidental condition.
[0010] Hence there exists a need to provide a position indication and locking mechanism for the modules of the motor control centre switch boards to indicate the operative position of the device to the user positively and to lock the modules to ensure the safety of the operating personnel during the maintenance operation.

[0011] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and sstudying the following specification.
C) OBJECT OF THE INVENTION
[0012] 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.
[0013] The primary object of the present invention is to provide a position indication and locking mechanism for modules of switch boards to indicate the operative position of the device to the user to ensure the safety of the operating personnel positively.
[0014] Another object of the present invention is to provide a position indicating mechanism to maintain the handle in a locked condition during an intermediate position to ensure the safety of the operating personnel.
[0015] Yet another object of the present invention is to provide a position indicating mechanism to provide an audible sound for indicating the locking of the modules of switchboards in any one of the three positions namely, service, test and isolated positions.
[0016] Yet another object of the present invention is to provide a position indication mechanism which is assembled easily and operated to achieve a desired position, without requiring the multiple rotations of the handle.
D) SUMMARY OF THE INVENTION

[0017] The various embodiments of the present invention provide a position indication and locking mechanism for feeder modules in a switchboard assembly. Examples of the modules includes, but are not limited to an actuator, modules of Motor Control Centre (MCC) switchboards, single phase circuit breakers, residual circuit breakers, multi phase circuit breakers and isolators.
[0018] According to one embodiment of the invention, a position indicating and locking mechanism includes a rotating shaft coupled to a feeder module. A handle which is detachable, an indexing bracket and an indexing guide are coupled to the rotating shaft. A spring is provided between the indexing bracket and the indexing guide. The spring is wound on a section of the rotating shaft which is extended between the indexing bracket and the indexing guide. Also the mechanism includes an indexing piate coupled to the rotating shaft and an indicator disc coupled to the indexing plate. The indexing bracket is provided with a plurality of slots at a predefined angle. The plurality of slots is designed to receive the handle for locking the handle at various indicating positions during the rotation of the shaft. The indicating positions include at least one of a Test condition, a connected or service condition and a disconnected condition.
[0019] The indicator disc is affixed with labels to indicate the various positions. The indexing guide is provided with a unique profile for locking the handle with the indexing plate at the various indicating positions. The indexing plate is arranged between the indexing bracket and the indicator disc. The indexing spring is adapted to maintain the indexing guide in contact with the indexing plate with a preset force. The handle is inserted into one of the plurality of slots and pushed to compress the spring between the indexing bracket and the indexing guide during the rotation of the shaft to achieve transition into various indicating positions. The indexing spring pushes the indexing guide into at least one of the slots of the indexing plate until the indexing guide strikes the indexing bracket.

[0020] The striking of the indexing guide with the indexing bracket creates an audible sound to indicate the movement of the module into one of the three positions. The spring pushes the indexing guide into at least one of the slots of the indexing plate and locks the indexing bracket with the indexing plate, when the shaft reaches one of the three positions. The shaft is rotated through 90° to achieve a transition from a disconnected condition to a test condition. The shaft is further rotated through another 90° to achieve a transition from the disconnected condition to connected condition. Thus the shaft is rotated successively through 90° to achieve the different positions.
[0021] The mechanism creates an audible sound, when the shaft reaches one of the three indicated positions such as a test condition, a connected condition or a disconnected condition to indicate a change in transition from one indicated position to another indicated position. The handle of the mechanism is locked once the shaft reaches one of the three indicated positions thereby restricting a user from removing out the handle at an intermediate position among the three indicated positions. The mechanism also restricts a user from keeping the modules of switchboards in between an intermediate position. The mechanism is easily operated to transfer a module from a disconnected condition to a test condition by rotating the shaft through 90° without a need for rotating the handle in multiple times. The mechanism provides a transition from the disconnected condition to the connected condition by rotating the shaft by another 90° thereby eliminating the need for rotating the handle in multiple times.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0022] 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:

[0023] FIG. 1 is a perspective view of a position indicating and locking mechanism for modules of switchboards according to one embodiment herein.
[0024] FIG. 2 is a perspective view of a rotating shaft of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.
[0025] FIG. 3 is a perspective view of a handle of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.
[0026] FIG. 4 is a perspective view of an indexing bracket of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.
[0027] FIG. 5 is a perspective view of an indexing guide of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.
[0028] FIG. 6 is a perspective view of a spring of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.
[0029] FIG. 7 is a perspective view of an indexing plate of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.
[0030] FIG. 8 is a perspective view of an indicator disc of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention.

[003 J ] Although 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 DESCRIP TION OF THE INVENTION
[0032] 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 ana* ofner cnanges may 6e macfe wi'tnouf departing from the scope of tne embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0033] The various embodiments of the present invention provide a position indication and locking mechanism for operating a module. Examples of the feeder modules include but are not limited to an actuator, modules of Motor Control Centre (MCC) switchboards, single phase circuit breakers, residual circuit breakers, multi phase circuit breakers and isolators.
[0034] According to one embodiment of the present invention, the mechanism includes a rotating shaft coupled to a feeder module, A detachable handle, an indexing bracket and an indexing guide are coupled to the rotating shaft. A spring is wound on the portion of rotating shaft arranged between the indexing bracket and the indexing guide. Also the mechanism includes an indexing plate coupled to the rotating shaft and an indicator disc coupled to the indexing plate. The indexing bracket and the indexing plate are provided with four slots at a predefined angle of 90° for locking the handle during the rotation of the shaft to

achieve a transition into various indicated positions. The indicated positions include a test position, a connected position and a disconnected position.
[0035] The indicator disc is affixed with labels to indicate the various desired positions. The indexing guide is provided with a unique profile for locking the handle with the indexing plate at the various indicated positions. The indexing plate is arranged between the indexing bracket and the indicator disc. The indexing spring is adapted to maintain the indexing guide in contact with the indexing plate with a defined force. The handle is inserted into one of the plurality of slots and pushed to compress the spring between the indexing bracket and the indexing guide during the rotation of the shaft to achieve a transition among the various indicated positions. The indexing spring pushes the indexing guide into at least one of the slots of the indexing plate until the indexing guide strikes the indexing bracket.
[0036] The striking of the indexing guide with the indexing bracket creates an audible sound which indicates that the module is moved to one indicated position. The spring pushes the indexing guide into one of the slots of the indexing plate and locks the indexing bracket with the indexing plate, once the shaft reaches one of the three indicated positions. The shaft is rotated successively through 90° to achieve a transition from one indicated to another indicated position among the three indicated positions.
[0037] FIG. 1 is a perspective view of a position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention. With respect to FIG. 1, the position indicating and locking mechanism includes a rotating shaft 101 used to couple with a feeder module. The electrical component herein is for instance a module of Motor Control Centre (MCC) switchboards. The mechanism is provided with a handle 102 for the rotation of the mechanism to change the position of the module. The various

indicated positions include a test position, a connected position and a disconnected position. The handle 102 includes a fastening means which enables the handle to be coupled to the rotating shaft. The handle 102 is detachably coupled to the shaft. The mechanism further includes an indexing bracket 103 and an indexing guide 104 coupled to the rotating shaft 101. A spring 105 is wound on the portion of the rotating shaft 101 which is arranged between the indexing bracket 103 and the indexing guide 104 as shown in FIG.l. An indexing plate 106 is coupled to the rotating shaft 101 and an indicator disc 107 is coupled to the indexing plate 106. The indicator disc 107 is adapted to provide a visual indication of the three desired positions. The indicator disc 107 has an opening through which the handle 102 is inserted and coupled with the rotating shaft 101. The indexing bracket 103 and the indexing plate 106 are provided with four slots designed to receive the handle 102. The slots are separated by a predefined angle of 90°.
[0038] In order to achieve a transition from one indicated position to another indicated position, the handle 102 is inserted into the slot provided in the indexing plate 106 and positively coupled with the shaft 101. After the insertion, the handle is pushed, which in turn compresses the indexing spring 105 arranged between the indexing bracket 103 and the indexing guide 104. The compression of the indexing spring 105 allows the handle to be advanced through the slot. Further, the shaft 101 of the mechanism is rotated easily through 90° to achieve a transition from one indicated position to another indicating position.
[0039] The indexing guide 104 is provided with a unique profile adapted to get fixed to the indexing plate 106. The indexing spring is designed to keep the indexing guide 104 in contact with the indexing plate 106 with a defined force. When the handle and the shaft reach a distinct position, the handle exerts a compressing force on the spring 105. The compression of the spring pushes the indexing guide 104 into the slot of the indexing plate 106 through the slots provided in the indexing bracket. The indexing guide 104 strikes the indexing

bracket 103, once the rotating shaft 101 reaches one of the three indicated positions.
[0040] The indexing guide 104 gets locked with the indexing plate 106 only when the rotating shaft 101 reaches one of the three indicated positions. This restricts the user to detach the handle 102 at an intermediate position. An audible sound is created following the striking operation indicating that the module is moved from one indicated position to another indicated position. The indicated positions are conveyed to the user with help of the labels affixed on the indicator disc 107. For example to achieve a transition from the disconnected position to the test position or test position to disconnected position or test position to connected position or connected position to test position, the rotating shaft 101 is rotated successively through an angle of90. To achieve a transition rrom the disconnected position to the connected position or from the connected position to disconnected position, the rotating shaft 101 is further rotated through an angle of 90°.
[0041] FIG. 2 is a perspective view of a rotating shaft 101 of the position indicating and locking mechanism for modules of switchboards according to one embodiment herein. The rotating shaft 101 provided in the position indicating and locking mechanism is coupled with the modules of the MCC switchboards. The rotating shaft 101 is adapted to receive the handle 102, which rotates the shaft 101 successively through 90° to achieve a transition between the various indicated positions. The rotating shaft 101 is further adapted to receive the indexing mechanism comprising the indexing guide, indexing plate, indexing bracket and the indexing spring.
[0042] FIG. 3 is a perspective view of a handle 102 of the position indicating and locking mechanism for modules of switchboards according to one embodiment herein. The handle 102 includes a clamp like structure to get

connected to the shaft 101. The handle 102 is adapted to rotate the shaft in order to achieve transitions between the various indicated positions. The handle 102 is rotated either manually or automatically according to the requirements. The handle 102 is made of a plastic, wood or any other suitable material. The handle 102 is detached from the shaft 10, once the shaft 101 reaches a definite indicated position.
[0043] FIG. 4 is a perspective view of an indexing bracket 103 of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention. The indexing bracket 103 includes a passage adapted to receive the shaft 101. The indexing bracket 103 is provided with four slots separated at a predefined angle of 90°. The indexing bracket 103is provided for locking the handle 102, when the shaft reaches a distinct position among the three states, say, test, disconnected and connected positions.
[0044] FIG. 5 is a perspective view of an indexing guide 104 of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention. The indexing guide 104 is provided with a unique profile 501 as shown in the figure 5. The unique profile 501 of the indexing guide 104 is forced into the slots of the indexing plate 106 during the shaft operation. The indexing guide 104 strikes the indexing bracket, when the shaft 101 achieves one of the indicated positions. An audible sound is created, when the indexing bracket is hit by the indexing guide 104 indicating transition from one indicated position to another indicated position. The indexing guide 104 locks the indexing bracket 103 and the indexing plate 106 at intermediate states which prevents the user from removing the handle 102 at intermediate positions.
[0045] FIG. 6 is a perspective view of a spring 105 of the position indicating and locking mechanism for modules of switchboards according to one embodiment herein. The spring 105 is wound on the rotating shaft 101. The

spring 105 is arranged between the indexing bracket 103 and the indexing guide 106 as shown in figure 1. The spring 105 provides the re-treating force required for the locking purpose of the shaft 101. The spring 105 is designed to maintain a defined force between the indexing guide 104 and the indexing plate 106. The compression of the spring 105 due to a force induced on the spring 105, when the handle 102 and the operating shaft 101 reaches the distinct position, pushes the indexing guide 104 into the slot of the indexing plate 106. The indexing guide 104 strikes the indexing bracket 103 and creates an audible sound. The audible sound indicates that the shaft is locked in one of the three indicated positions.
[0046] FIG. 7 is a perspective view of an indexing plate 106 of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention. The indexing plate 106 is a disc shaped structure provided with a profile including four slots which are mutually separated by a predefined angle of 90° and a passageway for the shaft. A unique profile of an indexing guide is forced into the slots of the indexing plate 106, when there is a transition of the shaft between the various indicated positions. Thus the unique profile of the indexing guide gets locked with the indexing plate 106 once the rotating shaft reaches one of the three indicated positions.
[0047] FIG. 8 is a perspective view of an indicator disc 107 of the position indicating and locking mechanism for modules of switchboards according to one embodiment of the present invention. The indicator disc 107 is affixed with labels to indicate the test, the connected and the disconnected positions.
G) ADVANTAGES OF THE INVENTION
[0048] The various embodiments of the invention provide a position indication and locking mechanism for a feeder module in a switchboard assembly. The mechanism creates an audible sound when the shaft reaches one of the three

indicated positions (Disconnected - Test - Coimzcled) indicating a change in transition from one indicated position to another indicated position. The handle of the mechanism is locked, once the shaft reaches one of the three indicated positions restricting a user from removing out the handle in the intermediate positions thereby preventing the damage to the feeder module.
[0049] The mechanism is easy to operate and provides transition from a disconnected condition to a test condition by rotating the shaft by 90°. The mechanism provides a transition from the disconnected condition to the connected condition by rotating the shaft further by 90° without rotating the handle for several times.
[OQ5G] 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.
[0051] 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 position indicating mechanism for an electrical module in switch board
assembly comprising:
A rotating shaft coupled to an electrical module;
A handle detachably attached to the rotating shaft;
An indexing bracket coupled to the rotating shaft;
An indexing guide coupled to the rotating shaft;
A spring arranged between the indexing bracket and the indexing guide;
An indexing plate coupled to the rotating shaft; and
An indicator disc coupled to the indexing plate;
Wherein the indexing bracket is provided with a plurality of slots at a predefined
angle for locking the handle during the rotation of the shaft until and unless the
module is moved to any one of the connected, test and disconnected conditions.
2. The position indicating mechanism of claim 1, wherein the plurality of slots includes four slots.
3. The position indicating mechanism of claim 3, wherein the four slots are mutually separated by a predefined angle of 90°.

4. The position indicating mechanism of claim 1, wherein the indexing guide is designed for locking the handle with the indexing plate at the connected, test and disconnected conditions.
5. The position indicating mechanism of claim 5, wherein the indexing guide is designed to lock the indexing bracket and the indexing plate at an intermediate position among the connected, test and disconnected conditions.
6. The position indicating mechanism of claim 1, wherein the indexing plate is arranged between the indexing bracket and the indicator disc.
7. The position indicating mechanism of claim 1, wherein the handle is inserted into one of the plurality of slots provided in the indexing plate and pushed to compress the spring between the indexing bracket and the indexing guide during the rotation of the shaft to achieve a transition among the connected, test and disconnected conditions.
8. The position indicating mechanism of claim 1, wherein the indicator disc includes labels to indicate the connected, test and disconnected conditions.
9. The position indicating mechanism according to claim 1, wherein the indexing spring is designed to maintain the indexing guide in contact with the indexing plate with a defined force.

10, The position indicating mechanism of claim 1, wherein the indexing spring pushes the indexing guide into one of the four slots in the indexing plate until the indexing guide strikes the indexing bracket to create an audible sound.
11, The position indicating mechanism of claim ], wherein the spring is designed to affix the indexing guide into one of the plurality of slots of the indexing plate for locking the indexing bracket with the indexing plate once the shaft reaches one of the indicating positions.
12, The position indicating mechanism according to claim 1, wherein the shaft is rotated successively through 90° to move the modules among the disconnected condition, the test condition and the connected conditions accordingly.