FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Support mechanism for efficient ejection of segmented lamination
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli,
Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Maharana Jayaprakash of Crompton Greaves Ltd, Stamping (M6) Division, Ahmednagar, Maharashtra, India, Maharashtra, 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 engineering,
Particularly, this invention relates to the field of punching assemblies and associated tools thereof.
Still particularly, this invention relates to a support mechanism for efficient ejection of segmental lamination.
Background of the Invention:
Segmental stamping stators are usually used for Hydro Generators, Wind mill Generators, HT Motors and the like and are usually manufactured using an inverted die in a Press machine. The inside part of rotary elements (i.e. Rotor) outer part i.e Stator, especially Hydro Generators, Wind mill Generators have large diameter for Stator used inside part for core building. Due to the bigger inner and outer diameter for Stator, these laminations are difficult to be manufactured in single punching operation and handling is also difficult. Because tool size becomes very big as well as press needs to be of a larger bed size. To make full circle, individual segmental laminations are used, which form equally even number for core building and winding.
A Stator core is a substantially circular core with a pre-defined height. The core is made of laminations, typically metal laminations. Typically, the

laminations are welded, in parts, for making core building. Instead of punching the entire circular lamination in one punch, the circle is broken into pre-defined number of arcs, and these segments (arcs) are punched from a metal sheet to form segmented lamination. Many such circular laminations are stacked one upon another to complete a core. The segmented laminations are circular at one (operative outer) end, and include slits (to cause fingers) at another (operative inner) end.
Figure 1 illustrates a segmented lamination.
Figure 2 illustrates a front view of the punching machine for punching said segmented lamination of Figure 1. Figure 3 illustrates a sectional top view of the punching machine for punching said segmented lamination.
Reference numeral 01 refers to a bottom bolster of the punching machine. Reference numeral 02 refers to a top bolster of the punching machine. Reference numeral 03 refers to a punching die of the segmental blanking tool or inverted dies. Reference numeral 04 refers to a punching die back-up of the inverted dies. Reference numeral 05 refers to a punch of the inverted dies. Reference numeral 06 refers to a to a punch back-up of the inverted dies. Reference numeral 07 refers to a stripper element of the inverted dies. Reference numeral 10 refers to a segmented lamination. Reference numeral 20 refers to a segmented lamination template of the inverted dies.
Figure 4 and 5 illustrate a schematic of the support mechanism for ejection of segmented (punched) lamination, according to the prior art.

During the process of punching, the lamination sheet (10) (figure 1) (typically, 0.5mm thickness sheet) is placed onto a platform in a punching machine, where an inverted die is typically used to carry out the punching. The fingers (12) of the lamination sheet are shown. Once, the punching is done, the punched segmented lamination, should ideally be ejected out smoothly without any constraint. For this purpose, during the process of punching, there is provided an ejector (12) on which support, bars (14) are placed in fingers as well as other positions of ejector (12) to placed symmetrically for springs or knockout actions, so that ejector should not deflect and movement in top die (03) smoothly while punching operation. Further, de-compressed springs (16) are placed at certain positions below the bars such that the punching force compresses the spring, and as the punching tool retracts, the compressed spring tries to regain its de-compressed state, thereby pushing the bars and the supported segmented (punched) lamination, and facilitating its ejection.
These bars are placed at according to geometry of locations below the ejector (12) segmented inverted dies Hence, ejection or smooth ejection is not guaranteed. This results in the segmented lamination being in the platform as newer laminations are received in an automated fashion, thereby resulting in breakdown of the punching tool elements viz. Ejector (12) Die (03) & punch,
Hence, there is a need for obviating the concerns of the prior art.

Objects of the Invention:
An object of the invention is to efficiently eject a segmented lamination, after it is duly punched in a punching machine using inverted dies.
Another object of the invention is to provide uniform load distribution to an Ejector while punching in order to accurately punch a segmented lamination and then eject the segmented lamination.
Summary of the Invention:
According to this invention, there is provided a support mechanism for efficient ejection for this type of geometry of segmented lamination, said mechanism adapted to be used in a inverted compound blanking dies for punching the segmented lamination using a punching die, said mechanism comprises:
a. at least a segmented lamination template, adapted to be placed under
said segmented lamination, having circumferential radius marginally
lesser than said segmented lamination, and having extending fingers
on its operative inner side with dimensions marginally lesser than the
fingers of said segmented lamination in order to provide ample and
sufficient support to the lamination in order to uniformly transfer the
distribution of spring pressure in order to efficiently eject said
segmented lamination; and
b. a plurality of uniformly distributed springs provided at pre-defined
compression and pre-calculated locations under said segmented

lamination template and said segmented lamination in order to ensure that the punching force of the punching tool decompresses all springs simultaneously to the same degree i.e. spring deflection, thereby providing a substantially uniform reaction force, as the punching is finished in order to de-compress and thereby dislodge (eject) said segmented lamination by acting upon said segmented lamination, said number of springs being decided in accordance with the geometrical aspects of lamination i.e. cutting perimeter, based on that cutting force and ejection force becomes calculated.
Typically, a plurality of said segmented lamination templates are placed side-by-side in order to cover a single segmented lamination
Typically, plurality of guide pillars in order to guide position of said segmented lamination template, securely.
Brief Description of the Accompanying Drawings:
This invention will now be described in relation to the accompanying drawings, in which:
Figures 6 and 7 illustrate a schematic of the support mechanism for efficient ejection of segmented (punched) lamination.
Detailed Description of the Accompanying Drawings:

According to this invention, there is provided a support mechanism for efficient ejection of segmented lamination, said mechanism adapted to be used in a punching machine for punching the segmented lamination using a punching die.
Figures 3 and 4 illustrate a schematic of the support mechanism for efficient ejection of segmented (punched) lamination.
In accordance with another embodiment of this invention, there is provided at least a segmented lamination template (20) having circumferential radius marginally lesser than said segmented lamination, and having extending fingers on its operative inner side with dimensions marginally lesser than the fingers of said segmented lamination. This provides ample and sufficient support and strength to the ejector plate in order to uniformly transfer the disbursing force in order to efficiently eject segmented lamination. Said segmented lamination template serves as an ejector plate.
Preferably, a plurality of said segmented lamination templates are placed side-by-side in order to cover a single segmented lamination. Typically, said segmented lamination templates are placed below said intended segmented lamination.
In accordance with another embodiment of this invention, there is provided a plurality of uniformly distributed heavy load yellow standard springs (22) provided at pre-defined and pre-calculated locations under said segmented lamination template and said segmented lamination. The number and

location of the springs are calculated in accordance with the size of the intended segmented lamination. The uniformity of the spring locations ensure that the punching force of the punching tool decompresses all springs simultaneously to the same degree, thereby providing a substantially uniform reaction force, as the punching is finished in order to de-compress and thereby dislodge (eject) said segmented lamination by acting upon said segmented lamination template. The number of springs is decided in accordance with the cutting perimeter of lamination geometry.
In accordance with yet another embodiment of this invention, there is provided a plurality of auxiliary guide pillars (24) in order to guide position of ejector plate inside die to ensure the up and down movement of ejector during cutting said segmented lamination template, securely.
The calculation for springs will now be defined in relation to a non-limiting exemplary embodiment of the invention:
For a product specification (lamination) with the following details:
Material thickness = 0.5mm
Inner diameter of product= 990.773, mm
Outer diameter of product= 1270.193, mm
Distance from back of st. slot to outer dia. = 63.06, mm
Distance between from Inner dia. to Outer dia. =139.71, mm
Distance between two edge stator slots in Inner dia size = 16.708 mm
The calculation of ejection force is as under:

Cutting perimeter of product (calculated from CAD software) =3657.366, mm
So, Cutting force = Cutting perimeter X material thickness X Shear Strength = 3657.366 X 0.5 X 47.5=86.86 Tons (Where 47.5 Kg/mm2 Shear strength of material and 0.5= Thickness of material) So, Ejection Force is 8 to 10 %age of cutting force (by thumb rule) = 8.6 Tons
In order to provide above Ejection force, equal number of Standard hardened springs (yellow) available in market, based on geometry of product, are placed symmetrically as follows:
1. G32 X 51 length 10 Nos.
2. G26 X 51 length 15 Nos.
3. G20 X 51 length 15 Nos.
These springs are mounted on said segmented lamination template.

We claim,
1. A support mechanism for efficient ejection of segmented lamination, said mechanism adapted to be used in a inverted compound blanking dies for punching the segmented lamination using a punching die, said mechanism comprising:
a. at least a segmented lamination template, adapted to be placed under
said segmented lamination, having circumferential radius marginally
lesser than said segmented lamination, and having extending fingers
on its operative inner side with dimensions marginally lesser than the
fingers of said segmented lamination in order to provide ample and
sufficient support and strength to the ejector plate to eject segmental
lamination in order to uniformly transfer the distribution of spring
pressure in order to efficiently eject said segmented lamination; and
b. a plurality of uniformly distributed springs provided at pre-defined
compression and pre-calculated locations under said segmented
lamination template and said segmented lamination in order to ensure
that the punching force of the punching tool decompresses all springs
simultaneously to the same degree, thereby providing a substantially
uniform reaction force, as the punching is finished in order to de
compress and thereby dislodge (eject) said segmented lamination by
acting upon said segmented lamination, said number of springs being
decided in accordance with cutting perimeter of lamination geometry.

2. A mechanism as claimed in claim 1 wherein, a plurality of said segmented lamination templates are placed side-by-side in order to cover a single segmented lamination
3. A mechanism as claimed in claim 1 wherein, plurality of guide pillars in order to guide position of said segmented lamination template, securely.