FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A tool assembly for removal of stator winding from a motor.
APPLICANTS :
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Chatterjee Chayan and Khavse Krishna; both of Crompton Greaves Limited, Machine (M7) Division, D-5 Industrial Area, MPAKVN, Mandideep - 462046, Madhya Pradesh, India; both Indian Nationals.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
This invention relates to the field of mechanical assemblies and mechanical engineering.
Particularly, this invention relates to motors.
Specifically, this invention relates to a tool assembly for removal of stator winding from a motor.
BACKGROUND OF THE INVENTION:
A motor for electrical purposes, i.e. an electric motor, is a device which converts electrical energy to mechanical energy. A motor contains two main components; stator, rotor. The rotor is the non-stationary part of a rotary motor, which rotates because the wires and magnetic field of the motor are arranged so that a torque is developed about the rotor's axis. The stator is the stationary part of a rotor system. The rotor has a fanning action.
In failed motors or electrical machines having stator windings, there is a need to remove the stator windings. The stator is shrink-fitted in to the motor frame. Hence, it is difficult to extract the stator windings from the frame or housing of the motor or electrical machine.
According to the prior art, localized rework of the winding is done. Prior practice would not effectively provide a solution to the problem. The prior art technique is a crude method. It is not reliable.

OBJECTS OF THE INVENTION:
An object of the invention is to provide an assembly which provides a relatively refined method of extraction of stator windings from a motor body or from the body of an electrical machine.
Another object of the invention is to provide an assembly which effectively aids in extraction of stator windings from a motor body or from the body of an electrical machine.
Yet another object of the invention is to provide an assembly which aids in extraction of stator windings from a motor body or from the body of an electrical machine without damage to the stator body or stator windings.
Still another object of the invention is to provide an assembly which aids in extraction of stator windings from a motor body or from the body of an electrical machine without damage to the motor body or to the body of the electrical rotating machine.
An additional object of the invention is to provide an assembly which aids in extraction of stator windings from a motor body or from the body of an electrical machine, thereby eliminating localized repairing techniques.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a tool assembly for removal of stator winding from a motor comprising a motor frame and a shrink-fitted stator winding

in said motor frame, said tool assembly comprises:
a. a pair of operatively vertically located elongate rods of equal length adapted
to be located over said stator winding; and
b. at least an operative horizontal rod adapted to be located such that it
connects the operative proximal ends of said operative operatively vertically
located elongate rods, said horizontal rod being adapted to receive vertical
pressure from a pressure exerting assembly for removal of said stator
windings from said frame.
Typically, said pair of operatively vertically located elongate rods are a welded pair of operatively vertically located elongate rods adapted to be independently welded on said stator windings, at their operative distal ends.
Typically, channels are formed of said horizontal rod.
Typically, said horizontal rod is a welded horizontal rod adapted to be welded on said pair of operative vertically located elongate rods, at their operative proximal
ends.
Typically, said tool assembly is a C-tool assembly.
Typically, said tool assembly is a fabricated C-tool assembly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a HT vertical motor with frame and winding.

The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a C-shaped tool assembly adapted to be used for removal of stator winding from a motor with the frame as depicted in Figure 1 of the accompanying drawings.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a HT vertical motor with frame and winding. A HT vertical motor comprises of a frame (1), a winding (2) which is shrink fitted inside the frame. During operation of the motor, if the winding fails, it needs rectification. In such cases, the winding is to be removed out from the stator frame.
As the diameter of the frame where the Drive End (DE) end-shield is fitted (a) is lesser than the bore of the frame where the stator winding is fitted, so pressing is not possible by any externally made pressing tool. The opposite end of the frame is the Non Drive End (NDE).
Hence, there is a need for a tool to perform such action of removal of winding out of the frame.
According to this invention, there is provided a tool assembly for removal of stator winding from a motor.
Figure 2 illustrates a C-shaped tool assembly adapted to be used for removal of stator winding from a motor with the frame as depicted in Figure 1 of the

accompanying drawings.
In accordance with an embodiment of this invention, there is provided a pair of operatively vertically located elongate rods (12) of equal length. The operative distal ends of the rods are located and are made to be in contact with an end ring of the stator windings. At their point of contact (as depicted by reference numeral W), welding is carried out so that each of the rods is securely located on to the end shield.
In accordance with an embodiment of this invention, there is provided an operative horizontal rod (14) adapted to be located such that it connects the operative proximal ends of the operative operatively vertically located elongate rods (12). Channels formed of the horizontal rod are welded on the top surface of the stator winding at diametrically opposite location.
Therefore, a C-tool assembly is fabricated which comprises the pair of operatively vertically located elongate rods and an operative horizontal rod disposed such that it connects the pair of operatively vertically located elongate rods.
A channel is inserted from the top and after proper alignment is welded with the already welded 2 no's channels.
The C-tool assembly is now ready for removing the stator winding from its position. The frame along with the C-tool is placed on a press and pressure up to 5 tons may be applied on top of the channel so that the winding is removed out. Due to this invention, the end ring is pressed effectively and pressure is not exerted on the coil directly, thereby preventing its damage.

The technical advancement of this invention lies in provisioning a solution for repairing the failure of HT vertical motors, by effectively removing stator windings. This solution is enabled by providing a tool assembly, as disclosed, adapted to exert pressure on an end ring of the stator windings, in order to remove the stator windings, thereby eliminating the practice of any localized repair methods can be stopped. The tool assembly is a C-tool assembly, as disclosed, for removing the stator winding from its position.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A tool assembly for removal of stator winding from a motor comprising a motor frame and a shrink-fitted stator winding in said motor frame, said tool assembly comprising:
a. a pair of operatively vertically located elongate rods of equal length
adapted to be located over said stator winding; and
b. at least an operative horizontal rod adapted to be located such that it
connects the operative proximal ends of said operative operatively
vertically located elongate rods, said horizontal rod being adapted to
receive vertical pressure from a pressure exerting assembly for removal
of said stator windings from said frame,
2. A tool assembly as claimed in claim 1, wherein said pair of operatively vertically located elongate rods are a welded pair of operatively vertically located elongate rods adapted to be independently welded on said stator windings, at their operative distal ends.
3. A tool assembly as claimed in claim 1, wherein channels are formed of said horizontal rod.
4. A tool assembly as claimed in claim 1, wherein said horizontal rod is a welded horizontal rod adapted to be welded on said pair of operative vertically located elongate rods, at their operative proximal ends.
5. A tool assembly as claimed in claim 1, wherein said tool assembly is a C-tool assembly.

6. A tool assembly as claimed in claim 1, wherein said tool assembly is a fabricated C-tool assembly.