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, 2005
COMPLETE SPECIFICATION (See section 10 and rule 13)
TITLE OF THE INVENTION
An adjustable apparatus for building a rotor core
APPLICANTS:
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR (S):
Saxena Shailesh, of Crompton Greaves Ltd, machine (M7) Division, D-5 Industrial Area, MPAKVN, Mandideep-462046, Madhya Pradesh, India; an Indian National.
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.
Particularly, this invention relates to motors.
Still particularly, this invention relates to an adjustable apparatus for building a rotor core.
Background of the Invention:
A motor is an electromechanical assembly which comprises stator, rotor, and commutator. While the stator is the stationary part of a rotor motor system, the rotor is the non-stationary part of a rotary motor.
An induction motor or asynchronous motor is a type of alternating current motor where power is supplied to the rotor by means of electromagnetic induction. In an induction motor, a rotor core is built by placing stampings over one another. A stamping is typically a lamination sheet with a centre hole. In the process of construction, the stampings whilst being placed one above another may not be placed exactly co-axially. The co-axial characteristic is important, else the stampings deviate away from the axis and form a crooked / tilted rotor core. This is troublesome while a bushing is inserted through the central hollow portion of the rotor core.

Hence, there is a need for an apparatus for building the rotor core with centre holes stampings in order to stack the stampings precisely in a co-axial manner.
Further, as the rating and make of the motor changes, the size of the motor, the rotor, and the stampings, thereby, change too. Thus, a single fixed shaft or a rigid apparatus is not enough to cater to multiple rotor sizes or multiple stampings.
Hence, there is a need for an adjustable apparatus for building a rotor core
Objects of the Invention:
An object of the invention is to provide an adjustable apparatus for building a rotor core.
Another object of the invention is to ensure that the rotor core is a substantially straight assembly.
Yet another object of the invention is to ensure co-axial stacking of stampings.
Still another object of the invention is to provide a uniform diameter for a rotor core.
An additional object of the invention is to provide flexibility of accommodating all sizes of building a rotor core.
Summary of the Invention:

According to this invention, there is provided an adjustable apparatus for building a rotor core, said apparatus comprises:
a. bottom support plate adapted to receive a foremost stamping for-building
said rotor core and upon which further stampings are stacked to complete
said rotor core building process, said bottom support plate laid out
substantially parallel to the horizontal plane;
b. plurality of radially located equi-angularly placed vertical shafts orthogonal
from said bottom support plate, said shafts cumulatively receiving each of
said stampings and defining an inner diameter of said rotor core; and
c. rail mechanism slotted in said bottom support plate adapted to receive each
of said vertical shafts independently in order to facilitate the moving of said
vertical shafts, each of said vertical shafts being mounted on a lead screw
arrangement and the opposite vertical shaft is attached to this lead screw
adapted to move horizontally on a rail or shaft from the circumference to the
centre of said bottom support plate or reverse, thereby providing an
adjustable apparatus for varying the diameter dimensions for different rotor
cores' building.
Typically, said rail mechanism includes a support element connecting mechanism to connect movement of said support elements simultaneously on said shafts such that said vertical shafts are adapted to simultaneously move towards the centre of the bottom support plate or move away from the centre of the bottom support plate, in that, the movement towards the centre marks a relative decrease in the inner diameter dimension and the movement away from the centre marks a relative increase in the inner diameter dimension.

Additionally, said apparatus includes a top plate, not extending beyond the dimensions of said vertical shafts, said top plate being similar in construction to the bottom plate to receive the operative top end of each of said vertical shafts and having a rail mechanism in order to move said vertical shaft according to the movement at said rail mechanism of bottom plate, in order to change the diameter dimensions.
Brief Description of the Accompanying Drawings:
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates an adjustable apparatus for building a rotor core; and
Figure 2 illustrates an adjustable apparatus for building a rotor core with the rotor core built around it.
Detailed Description of the Accompanying Drawings:
According to this invention, there is provided an adjustable apparatus for building a rotor core.
Figure 1 illustrates an adjustable apparatus (100) for building a rotor core.

Figure 2 illustrates an adjustable apparatus (100) for building a rotor core with the rotor core (50) built around it.
In accordance with an embodiment of this invention, there is provided a bottom support plate (20) which receives the foremost stamping for building the rotor core (50) and upon which further stampings are stacked to complete the rotor core (50) building process. The bottom support plate (20) is laid our substantially parallel to the horizontal plane or the ground.
In accordance with another embodiment of this invention, there is provided a plurality of radially located equi-angularly placed vertical shafts (22) orthogonal from said bottom support plate (20). These shafts define the inner diameter of the rotor core (50). The stampings are slid about the vertical shafts from the operative top such that the vertical shafts define and match the inner diameter of (stampings of) the rotor core Depending upon the central hole of the stampings, the vertical shafts (22) are adjusted to define the inner diameter. The vertical shafts (20) are adapted to simultaneously move towards the centre of the bottom support plate (20) or move away from the centre of the bottom support plate (20), in that, the movement towards the centre marks a relative decrease in the inner diameter dimension and the movement away from the centre marks a relative increase in the inner diameter dimension.
In accordance with yet another embodiment of this invention, there is provided a rail mechanism (24) slotted in said bottom support plate (20) adapted to receive each of said vertical shaft (22) independently in order to facilitate the moving of said vertical shafts (22). Each vertical shaft (22) is mounted on a support element

adapted to move horizontally on a rail or shaft from the circumference to the centre of the plate or reverse. Thus, an adjustable apparatus for varying the diameter dimensions is achieved for different rotor core building.
In accordance with yet another embodiment of this invention, there is provided with a lead screw mechanism to adjust vertical shaft as per varying diameter of the rotor core stamping, and the opposite vertical shaft is attached to one lead screw for precise control on the diameter dimension.
There may be a top plate similar to the bottom plate to receive the top part of the vertical shaft. There is a rail mechanism to move the vertical shaft as described above with respect to the bottom support plate in order to change the diameter dimensions.
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. An adjustable apparatus for building a rotor core from a plurality of stampings with a central hole, said apparatus comprising:
a. bottom support plate adapted to receive a foremost stamping for building
said rotor core and upon which further stampings are stacked to complete
said rotor core building process, said bottom support plate laid out
substantially parallel to the horizontal plane;
b. plurality of radially located equi-angularly placed vertical shafts orthogonal
from said bottom support plate, said shafts cumulatively receiving each of
said stampings and defining an inner diameter of said rotor core; and
c. rail mechanism slotted in said bottom support plate adapted to receive each
of said vertical shafts independently in order to facilitate the moving of said
vertical shafts, each of said vertical shafts being mounted on a lead screw
arrangement and the opposite vertical shaft is attached to this lead screw
adapted to move horizontally on a rail or shaft from the circumference to the
centre of said bottom support plate or reverse, thereby providing an
adjustable apparatus for varying the diameter dimensions for different rotor
cores' building.
2. An apparatus as claimed in claim 1 wherein, said rail mechanism includes a support element connecting mechanism to connect movement of said support elements simultaneously on said shafts such that said vertical shafts are adapted to simultaneously move towards the centre of the bottom support plate or move away from the centre of the bottom support plate, in that, the movement towards the centre marks a relative decrease in the inner diameter dimension

and the movement away from the centre marks a relative increase in the inner diameter dimension.
3. An apparatus as claimed in claim 1 wherein, said apparatus includes a top plate, not extending beyond the dimensions of said vertical shafts, said top plate being similar in construction to the bottom plate to receive the operative top end of each of said vertical shafts and having a rail mechanism in order to move said vertical shaft according to the movement at said rail mechanism of bottom plate, in order to change the diameter dimensions.