FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
FOOL-PROOFING MECHANISM FOR MCC MODULE;
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 THE INVENTION
The invention relates to a MCC Module, and more particularly to a fool-proofing mechanism for toggling between positions of a MCC Module.
BACKGROUND OF THE INVENTION
A MCC Module has three distinct positions i.e. service, test and isolation. A racking mechanism is used to move the MCC Module from isolation to test position and then test to service position and vice versa. When power contacts and auxiliary contacts both are engaged it is called as service position. When power contacts are engaged and auxiliary contacts are disengaged it called as test condition. When both contacts are disengaged it is called as isolation condition.
As per one technique to move the MCC Module between positions a racking mechanism is used, wherein front door of MCC Module is opened and the MCC Module is moved physically.
As per another technique MCC Module is moved between these distinct positions without physically moving the MCC Module. In this technique, in door closed condition power contacts and auxiliary contacts are moved to move MCC Module between positions.
However in this technique it is difficult to identify position of the MCC Module, and hence while moving MCC Module from one position to other, if the racking mechanism is withdrawn in between when contacts are not properly engaged it may create an arc which can cause damage to the MCC Module and surrounding equipment.

SUMMARY OF THE INVENTION
Accordingly the present invention provides a fool-proofing mechanism for toggling between positions of a MCC Module, the mechanism comprising a handle assembly to engage with a mechanism shaft of the MCC Module comprising, a front segment, the front segment having a square cross-section; a middle segment, the middle segment having a circular cross-section and a rear segment, the rear segment having a square cross-section internally and a circular cross-section externally, a part of the rear segment being disposed inside the middle segment to receive at-least a part of the front segment to couple the segments, and a bracket mounted on the MCC Module, the bracket comprising, a front plate, the front plate having a square aperture for receiving the handle assembly; and rear plate, the rear plate having a circular aperture for receiving the mechanism shaft, wherein when the handle assembly is engaged, the front segment of the handle assembly will be in between the plates of the bracket, and the middle segment of the handle will remain in the aperture of the front plate till one of the positions is reached.

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.
Figure 1 shows a fool-proofing mechanism in accordance with an embodiment of the invention.
Figure 2 shows an exploded view of the handle assembly in accordance with an embodiment of the invention.
Figure 3 shows a bracket in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of the present invention provide a fool-proofing mechanism for toggling between positions of a MCC Module. The fool proofing mechanism comprises a handle assembly to engage with a mechanism shaft of the MCC Module comprising, a front segment, the front segment has a square cross-section; a middle segment, the middle segment has a circular cross-section and a rear segment, the rear segment has a square cross-section internally and a circular cross-section externally, a part of the rear segment being disposed inside the middle segment to receive at-least a part of the front segment to couple the segments, wherein the circular cross-section of the rear segment allows coupling of the rear segment with the middle segment, and the square cross-section of the rear segment allows the front segment to be coupled with the segments; and a bracket mounted on the MCC Module, the bracket comprising a front plate, the front plate extending outwardly and has a square

aperture for receiving the handle assembly; and a rear plate, the rear plate extending outwardly and has a circular aperture for receiving the mechanism shaft, wherein to toggle the MCC Module between positions, the handle assembly is pressed on the mechanism shaft and rotated, wherein when the handle assembly is pressed the front segment of the handle assembly will be in between the plates of the bracket, and the middle segment of the handle will remain in the aperture of the front plate till one of the positions is reached.
Figure 1, shows a fool proofing mechanism 1000 in accordance with an embodiment of the invention. The mechanism comprises a handle assembly 100, a bracket 200, a mechanism shaft 300, and a guide support 400. The mechanism shaft 300 has a square cross-section and is mounted on MCC Module via guide support 400, and handle assembly 100 engages with mechanism shaft 300 through bracket 200, wherein handle assembly 100 is pushed on mechanism shaft 300 to engage with mechanism shaft 300 and then rotated to toggle the MCC Module between positions. As handle assembly 100 is rotated, power contacts of MCC Module move and accordingly the MCC Module is toggled between different positions i.e. service, test and isolation. Further, fool proofing mechanism 1000 comprises of an operating handle 500 which is coupled to handle assembly 100.
Handle assembly 100 as shown \n figure 2 comprises of a front segment 10, a middle segment 20 and a rear segment 30, wherein the segments are coupled together. In this regard, front segment 10 has a square cross-section, middle segment 20 has a circular cross-section, and rear segment 30 has square cross-section internally and a circular cross-section externally, wherein a part of rear segment 30 being disposed inside middle segment 20 to receive at-least a part of front segment 10 to couple the segments, wherein the circular cross-section of rear segment 30 allows coupling of rear segment 30 with middle segment 20, and the square cross-section of rear segment 30 allows front segment 10 to be coupled with the segments. Further each segment has a hole 40 formed such that each hole intersects the other when the

segments are coupled. A pin 50 is inserted through these holes 40 to hold the coupled segments. Further a spring 60 is retained inside middle segment 20 when the segments are coupled such that, spring 60 rests in front of rear segment 30 and on rear of front segment 10.
Figure 3 shows bracket 200 as per an embodiment of the invention. Bracket 200 comprises
a front plate 110 and a rear plate 120 extending outwardly. Front plate 110 has a square
aperture 105 for receiving the handle assembly 100; and rear plate 120 has a circular aperture
115 for receiving mechanism shaft 300. To toggle the MCC Module between positions, the
handle assembly 100 is engaged on mechanism shaft 300, by pressing it on mechanism shaft
300 and rotated through bracket 200. When handle assembly 100 is pressed on mechanism
shaft 300, front segment 10 of handle assembly 100 will be in between front plate 110 and rear
plate 120 of bracket 200, and middle segment 20 of handle assembly 100 will remain in square
aperture 105 of front plate i.e. square cross-section of front segment 10 will pass through
square aperture 105 of front plate 110, and second segment 20 having a circular cross-section
will remain in contact with square aperture 105 of front plate 110. Second segment 20 will
remain in contact with square aperture 105 of front plate 110 till a position is reached, and when
a position is reached, handle assembly 100 is released from between the plates, and front
segment 10 of handle assembly 100 will be in contact with square aperture 105 of front plate,
and handle assembly 100 can be withdrawn. Handle assembly 100 can only be withdrawn after
completion of every 90 ° rotation.
Jn an embodiment of the invention, to toggle the MCC Module to different positions, an operator engages handle assembly with a mechanism shaft through a bracket by pressing^the handle assembly on the mechanism shaft and rotating the handle assembly, wherein the handle assembly can only be withdrawn when the handle assembly completes a 90° rotation.

Advantageously, handle assembly of the present invention enables an operator to be aware of change in position of MCC Module, preventing unintentional positioning of MCC Module and only allows the operator to withdraw the handle assembly when MCC Module is toggled from one position to other, preventing arc formation which can damage the MCC Module.
While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

WE CLAIM:
1. A fool-proofing mechanism for toggling between positions of a MCC Module, the mechanism comprising:
(a) a handle assembly to engage with a mechanism shaft of the MCC Module
comprising:
a front segment, the front segment having a square cross-section; a middle segment, the middle segment having a circular cross-section and a rear segment, the rear segment having a square cross-section internally and a circular cross-section externally, a part of the rear segment being disposed inside the middle segment to receive at-least a part of the front segment to couple the segments, and
(b) a bracket mounted on the MCC Module, the bracket comprising:
a. a front plate, the front plate having a square aperture for receiving the handle
assembly; and
b. a rear plate, the rear plate having a circular aperture for receiving the
mechanism shaft,
wherein when the handle assembly is engaged, the front segment of the
handle assembly will be in between the plates of the bracket, and the middle
segment of the handle will remain in the aperture of the front plate till one of
the positions is reached.
2. The mechanism as claimed in claim 1, wherein to toggle the MCC Module between positions, the handle assembly is engaged by pressing it on the mechanism shaft and rotated.
3. The mechanism as claimed in claim 1, wherein rotation of the mechanism shaft moves contacts of the MCC Module.

4. The mechanism as claimed in claim 1, wherein a hole is formed on all the segments, each hole intersects the other when the segments are coupled.
5. The mechanism as claimed in claim 1 further comprises a pin, the pin holds the coupled segments through the holes.
6. The mechanism as claimed in claim 1 further comprises a spring, the spring retained inside the middle segment when the segments are coupled.
7. The mechanism as claimed in claim 1, wherein at-least a part of the mechanism shaft has a square cross-section.
8. The mechanism as claimed in claim 1, wherein the mechanism shaft is mounted on the MCC Module via a guide support.
9. The mechanism as claimed in claim 1 further comprises of an operating handle coupled to the handle assembly.
10. The mechanism as claimed in claim 1, wherein the circular cross-section of the rear segment allows coupling of the rear segment with the middle segment, and the square cross-section of the rear segment allows the front segment to be coupled with the segments.