FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention: SAFETY SHUTTER MECHANISM FOR OPEN
DOOR OPERATION OF MOTOR CONTROL CENTRE MODULE
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
This invention relates generally to a motor control centre module. More particularly present invention relates to a safety shutter mechanism for open door operation of motor control centre module.
BACKGROUND AND THE PRIOR ART
Present invention relates to safety shutter for motor control centre. Motor control centre receives power from power control centre and feed 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 withdrawable, semi-withdrawable, 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.
Therefore there is a need to provide a safety shutter to isolate live conductor like droppers from functional unit like module when it is not in service position. The present invention therefore provides a Safety shutter which isolate live conductor like droppers from functional unit like module when it is not in service position. Functional unit has 3 different positions service, test and isolation. In service condition moving contacts are engaged with stationary conductor whereas in test and isolation both are disengaged.
OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.

Another object of the present invention is to provide a safety shutter mechanism for open door operation of motor control centre module.
Yet another object of the present invention is to provide a lever which will operate the safety shutter mechanism when the module is inserted.
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 safety shutter mechanism for open door operation of motor control centre module.
According to one embodiment of the present invention, there is provided a safety shutter mechanism for open door operation of motor control centre module, said mechanism comprising a shutter means to isolate live conductor from functional unit; a lever for operating said safety shutter mechanism fixed on a tray using a pair of pins; said pins fixed with nylock allowing free linear movement of said lever along said tray, said lever having plurality of slots in upper and lower flanges; wherein said safety shutter adapted to remain open throughout the operation of said module and closed when said module is withdrawn.
BRIEF 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.
Fig 1 illustrates the shows the slot on the lever on the bottom flange.
Fig 2 illustrates the module just racked in the panel.
Fig 3 illustrates the isolated position of the module when the mechanism is fully operated.
Fig 4 illustrates the 'service' position of the safety shutter.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Accordingly in the present invention, when module is in test or isolation, safety shutter is in closed condition. When module is rack in the panel it slowly starts opening. It opens completely when module comes to service condition and moving contacts engaged with stationary current carrying conductor. The movement of safety shutter depends upon the movement of module.
When module is racking out the safety shutter starts closing with respect to
module movement. It completely closes down when moving contact completely
disengaged from stationary conductor. This assures safety of person who
is working in front of panel. The person will never see live contact even if module is in isolation position since safety shutter becomes the barrier between live contact and functional unit. Vice versa it will allow engaging contacts when module is racked in.
Safety shutter is a mechanism which isolate live conductor like droppers from functional unit like module when it is not in service position. This safety shutter is nothing but a barrier between live contact and the functional unit

The primary object of the present invention is to provide a lever which will operate the safety shutter mechanism when the module is inserted and comes to isolated position. In open door operation of the module, power contacts are moving with the module. Thus, the care should be taken such that the power contacts will not hit the safety shutter at any position. So, operating the safety shutter mechanism once the module is inserted in isolated condition will take care of this condition. Afterwards, during the operation of the module from isolated to test to service, the lever will operate in such a way that the safety shutter mechanism will remain in the same position and the safety shutter will remain open. Similarly, while operating the module from service to test to isolated, the lever will ensure that the safety shutter will remain open throughout the operation of the module, once the module is withdrawn, the safety shutter mechanism will operate closing the shutter and ensuring the prevention of the direct contact between live busbar and the person operating the module.
The main purpose of the present invention is that in open door operation of the module, the safety shutter mechanism has to be operated with the help of one lever. The condition of operating the safety shutter mechanism is that, the safety shutter should open when the module comes in isolated position. The shutter should remain open when the module is operated from isolated to test to service and vice a versa. The safety shutter should close when the module is taken out of the panel beyond isolated position ensuring that no live part is accessible.
Construction:
The main embodiment of the patent consists of one mild steel lever fixed on the tray with the help of 2 pins. Fig. 1 shows the MILD STEEL (M.S.) lever. Point 1 indicated in fig.l shows the slot on the lever on the bottom flange. In this slot, 2 pins will get fixed on the tray which will hold the lever with the tray. Point 4 in fig.l shows the circular slot through which the pin has to be assembled on the tray. These pins are fixed with the help of nylock so that they will allow the free

linear movement of the lever along the tray. Point 2 in fig.l indicates the profile which the pin will follow when the module is moved from isolated to service position. Point 3 of fig.l shows the slot on the upper flange of the lever. One pin fixed on the module base will move along this slot resulting in the movement of the lever and thus the opening of the safety shutter. For the assembly of the pin on the tray, a hole is provided on the lever,
The assembly of the pins is done in following manner:
1. Insert the first pin from the hole on the lever in the hole on the tray. Put the nylock to the pin from the bottom side of the tray.
2. Then move the lever to rear side linearly along the surface of the tray. When the hole on the lever and the hole on the tray are matching, insert another pin from the hole on the lever, and fix the nylock from the bottom side of the tray.
One pin is provided on the bottom side of the module base.
Fig.2 shows the module just racked in the panel. When the module is racked in, As indicated by point 1 in fig,2, the safety shutter mechanism is not operated in this position. The pin mounted on the module base will hit the cam slot on the M.S. lever as shown by point 2 in fig.2 and try to rotate the lever by moving in the cam slot. But the pins mounted on the tray, which fixes the M.S. lever are in the slot such that they will not allow the lever to rotate. So the pin on the module will try to move the lever inside in the linear motion. The lever touches the safety shutter mechanism. Thus, because of the linear motion of the lever, the safety shutter mechanism is also pushed in thus opening the safety shutter fully once the module comes to isolated position.
Fig.3 shows the isolated position of the module when the mechanism is fully operated as shown by point 1 in fig.3. The safety shutter is fully opened. The

requirement is such that the safety shutter should remain open so long as the module is inside the panel. This calls for the stopping of the safety shutter mechanism once the safety shutter is fully opened in isolated position of the module. Thus, on the lower flange of the M.S. lever, the slot is provided in such a way that one pin becomes pivot and the lever will rotate in clockwise direction. The outer side of the upper flange is given in such a way that during the clockwise rotation of the lever, the outer side of the lever always touches the safety shutter mechanism at one point and holds the mechanism in same position during the movement of the module and keeps the safety shutter open.
Fig.4 shows the 'service' position of the safety shutter. Point 1 in fig.4 shows the fully rotated lever and the safety shutter mechanism remaining open throughout the motion of the module.
While taking the module from service to test to isolate, the safety shutter will remain open as the lever will rotate in anticlockwise direction. This will ensure that the safety shutter remains open when the power contact is making contact with the live busbar i.e. dropper. Also, it will ensure that the power contact or power contact housing will not hit any part of the safety shutter thus avoiding the breakage of the shutter. When the module moves out beyond isolated condition, the pin on the module base will move in the cam slot in such a way that this cam slot will ensure that the pin will move the lever outward. The spring in the safety shutter mechanism will help in the outward movement of the M.S. Lever. Thus, the safety shutter will close as soon as the module is taken out of the panel.
ADVANTAGES:
1. Once the module is inserted in the panel, the safety shutter will open when the module is in isolated position and remains open throughout the operation of the module.

2. When module is taken out from the panel, the safety shutter will close ensuring that the live busbars are not directly accessible.
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 safety shutter mechanism for open door operation of motor control
centre module, said mechanism comprising:
a shutter means to isolate live conductor from functional unit;
a lever for operating said safety shutter mechanism fixed on a tray using a pair of pins; said pins fixed with nylock allowing free linear movement of said lever along said tray, said lever having plurality of slots in upper and lower flanges;
wherein said safety shutter adapted to remain open throughout the operation of said module and closed when said module is withdrawn.
2. Mechanism as claimed in claim 1 wherein a pin fixed on a module base moving along a slot provided in upper flange of said lever thereby operating said safety shutter.
3. Mechanism as claimed in claim 1 and 2 wherein said upper flange adapted to actuate said safety shutter mechanism on rotation of said lever.
4. Mechanism as claimed in claim 1 wherein said lever is substantially a mild steel lever.
5. Mechanism as claimed in claim 1 further comprising a spring means adapted to provide outward movement of said lever.

6. A safety shutter mechanism for open door operation of motor control centre module as herein described and illustrated with reference to accompanying drawings.