FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
POSITION INDICATION MECHANISM FOR A MOTOR CONTROL CENTER;
LARSEN & TOUBRO LIMITED, A COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956, WHOSE ADDRESS IS L&T HOUSE, BALLARD ESTATE, MUMBAI - 400 001, MAHARASHTRA, INDIA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF INVENTION
The present invention relates to control of a motor and more particularly it relates to position indicator for motor control centre. BACKGROUND OF INVENTION
A motor control center (MCC) is an assembly of one or more enclosed sections having a common power bus and principally containing motor control units. In modern practice, motor control centers are a factory assembly of several motor starters. A typical motor control centre receives power from power control centre and feeds it to a number of load points, majority of them are motors operating on an electrical installations. It is a multi compartment with a common bus system to distribute power. On a common bus system, motor control units are mounted individually to feed respective motors. These individual feeders normally called as 'modules', individual feeders are typically constructed as withdraw-able, semi-withdraw-able, and plug-in and it contains motor controlling, protection and monitoring equipments. When modules are operated, it connects/disconnects the incoming bus to motor through control and protection equipments. Withdraw-able module has a special type of mechanism to envisage the operation.
A typical motor control centre assembly known in the prior art, generally has its position indication placed deep inside the module. As a result, it was difficult to know the position of the module. Also there is no specific mechanism to show the position of the modules and the visibility in top/bottom most feeders in a panel are poor. This leads in difficulty for an operator to operate the module and check the functionality of the same.
Also, in the existing systems, the indication mechanisms were used with screw rod type having complex assemblies and calibrations was also required.
A novel position indication mechanism for motor control centre assembly is therefore required and the same is disclosed as follows.

SUMMARY OF THE INVENTION
It is an object of the present invention to provide indication for motor control centre which is compact in size and overcomes the constraints of previous mechanisms known in the art.
In accordance with this, there is provided a position indication mechanism for indicating position of a module in a Motor Control Center.
In one embodiment herein, a chassis is provided along with a cam that is mounted on a shaft. A follower is mounted on a bracket that allows the follower to move with the cam. When an operator operates the module, the shaft and follower moves with respect to the fixed chassis. When the shaft is rotated, cam rotates and as the cam rotates, profile or shape of the cam causes the follower to move in a particular way thereby indicating the corresponding position of the module. The positions to be indicated include Isolate, Test, and Service positions.
In one embodiment herein, the module is an individual feeder in motor control centre. Said module comprises control, protection and monitoring equipments for motors.
In one embodiment herein, the position indicator is placed close to door/control plate so that it clearly shows the mechanical status of the module even if it is a topmost or a bottom-most module.
In one embodiment herein, door cam IOCKS are provided to ensure that the same can be opened with special tools only.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Fig. 1 shows the arrangement of modules in motor control centre and projected view of the module for depicting position indicator according to an embodiment of the present invention.

Fig. 2 shows overall view of the motor control centre module and its components from front side according to an embodiment of the present invention.
Fig. 3 shows the main assembly of mechanism components and it also shows the isolated position of the module with its direction of operation for test and services position according to an embodiment of the present invention.
Fig. 4 shows the test position of the modules with its direction of operation for services position according to an embodiment of the present invention.
Fig. 5 shows the service position of the module according to an embodiment of the present invention.
Fig. 6 shows the front view of the indication mechanism when control plate is opened according to an embodiment of the present invention.
Fig. 7 illustrates the mechanism with all components including an operating handle according to an embodiment of the present invention.
Fig. 8 shows exploded rear view of the indication mechanism with main mechanism on normal view according to an embodiment of the present invention.
Fig. 9 shows exploded side view of the indication mechanism according to an embodiment of the present invention.
Fig. 10a, 10b, and 10c show the individual components used in indication mechanisms according to an embodiment of the present invention.
DESCRIPTION OF THE INVENTION
Disclosed herein is a position indication mechanism for indicating position of a module in a motor control centre. Said mechanism provides indication by using cam-follower method which brings the indication close to the door or control plate. The mechanism is compact in size and overcomes the constraints of previous mechanisms known in the art.
In one embodiment herein, the mechanism comprises a chassis, a cam mounted on a shaft and a follower mounted on a bracket that allows the follower to move with the cam. When the shaft is rotated, cam rotates and as the cam rotates, profile or shape of the cam causes the follower to move in a particular way thereby indicating the corresponding position of the module.

Fig. 1 shows arrangement of modules in motor control centre and projected view of the module depicting position indicator according to an embodiment of the present invention. The indication mechanism has an indication 101 to show the position of the modules 106 in motor control centre having three positions including 1) Isolate Position (I), 2) Test Position (T), and 3) Service Position (S). The modules herein refer to the individual feeders in motor control centre, typically comprising control, protection and monitoring equipments for motors. Fig.1 also shows position indicator placed close to door 104 and/or control plate 105 so that it can show clearly the mechanical status of the module 106 even if it is the topmost or the bottommost modules. Also door cam locks 102 are provided to ensure that it can be opened only with special tools.
Fig. 2 shows overall view of the motor control centre module and its components from front side according to an embodiment of the present invention. An Indication window may be provided on the control plate as shown. The control plate may be mounted on the chassis 201 which is used to mount the motor control / monitoring equipments such as relays, on, off lamps, etc. Rail brackets 202 mounted on chassis 201 to guide the module when it's taken from tray 203.
Fig. 3 shows the main assembly of mechanism 303 components and it also shows the isolate 302 position according to an embodiment of the present invention. An indexing bracket 304 is provided to ensure that any operator can only remove the operating handle in respective positions. The indication bracket 301 is basically a follower with a space provided for showing indication along with control plate 105. The cam is coupled with mechanism shaft which is main interface for operator and rack in and rack out mechanism. When an operator rotates the mechanism shaft through indexing bracket 304 with the help of operating handle, cam rotates with mechanism shaft thereby allowing the follower to reach another position and eventually showing the corresponding position. Mechanism plate 305 provided to mount mechanism components and it's mounted on chassis 201.
Fig. 4 shows the test position 401 and service direction of operation according to an embodiment of the present invention.
Fig. 5 shows the service position 501 according to an embodiment of the present invention.

As explained above, Fig. 3, Fig. 4 and Fig. 5 show the directions 302, 401, 501 in which mechanism 303 is rotated. These figures also show the respective positions of the cam, follower movements and front views of the modules. Operator inserts the handle through control facia 103, indexing bracket 304 and operates the mechanism 303 and when mechanism shaft rotates, cam also starts rotating and follower moves to show the respective position of the module.
Fig. 6 shows the front view of the indication mechanism when control plate is opened according to an embodiment of the present invention. As can be seen in the figure, the indication brackets 301 are mounted on the indexing bracket 304 by rivets 601. The Indexing bracket 304 is mounted on the mechanism plate 305 and cam is mounted on the mechanism shaft 602.
Fig. 7 illustrates the mechanism with all components including an operating handle 702 according to an embodiment of the present invention. The indication bracket 301 is having rivets 601 and indexing bracket 304 is having slot 701 as shown. When cam rotates the follower moves in the slot 701 provided on indexing bracket 304 and with rivets 601. This cam follower mechanism basically converts the rotary motion to linear within less space provided for indication.
Fig. 8 shows exploded rear view of the indication mechanism with main mechanism on normal view according to an embodiment of the present invention. Here the cam 802 is inserted on the mechanism shaft and the indexing bracket 304 with indication bracket 301 riveted is as sub assembly mounted on the mechanism plate 305.Operating shaft 602 provided, so the user to insert operating handle 801 and operate the mechanism for respective positions.
Fig. 9 shows exploded side view of the indication mechanism according to an embodiment of the present invention. Here the indication bracket 301 is riveted 601 on the indexing bracket 304 which is having slot 701 provision. When mechanism rotates cam 802 also starts rotating and follower shows the indication in the control plate cut out with respective positions.

Fig. 10a, 10b, 10c show the individual components used in indication mechanisms according to an embodiment of the present invention. Fig. 10a is indexing bracket which ensures that operator can only insert/ remove the handle in any of the three positions explained earlier. Fig. 10b is indication bracket acts as follower, which is mounted on the indexing bracket by rivets. Fig. 10c is cam, which is mounted on the mechanism shaft, when rotates converts rotary to linear motion along with indication bracket to show indication.
Thus the present invention provides clear indications of the motor control centre modules having different states. The present invention uses cam follower method to provide status of the modules so that operator can easily know the positions of the module. In the Prior art, the previous indications were not placed close to the door /control plate so the operator had to struggle to know the position of the modules which are used in bottom or top most compartments in the motor control centre. Further, the present mechanism uses less number of components and facilitates in easy calibration of the modules.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

We Claim
1. A Position Indication Mechanism for indicating position of a module in a Motor Control
Center, the mechanism comprising:
a chassis;
a cam mounted on a shaft;
a follower mounted on a bracket that allows the follower to move with the cam; wherein the shaft and follower moves with respect to the fixed chassis and when the shaft is rotated, cam rotates and as the cam rotates, profile or shape of the cam causes the follower to move in a particular way thereby indicating the corresponding position of the module.
2. The Position Indication Mechanism as in claim 1, wherein motor control centre module comprises various positions including isolate, Test, and Service.
3. The Position Indication Mechanism as in claim 1, wherein the module is an individual feeder in motor control centre.
4. The Position Indication Mechanism as in claim 1, wherein the module comprises
control, protection and monitoring equipments for motors.
5. The Position Indication Mechanism as in claim 1, wherein the position indicator is placed close to door/control plate so that it clearly shows the mechanical status of the module even if it is a topmost or a bottom-most module.
6. The Position Indication Mechanism as in claim 1, wherein door cam locks are provided to ensure that the same can be opened with special tools only.