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
PROVISIONAL SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Loaded Dynamic Seasoning process for DC Motor Commutator


APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company

INVENTOR
Moudghil Ashish Saurabh of Crompton Greaves Limited, M7 Division, D5 Industrial Area, Mandideep, 462046, Madhya Pradesh, India, an Indian national
PREAMBLE TO THE DESCRIPTION
The following specification describes the invention


This invention relates to a Dynamic Seasoning process carried on a DC Motor's Commutator.
In Prior art, the commutator consists of a number of copper sheets which are separated through thin slices of mica sheet. Female V Grooves of a particular profile is there at both sides of the assembly of Copper-Mica. 2 Metalic parts with a male V Groove are tightened on both the sides of the Copper-Mica Assembly. The Metalic parts are locked with the help of a series of bolts at the periphery of the steel parts.
To achieve positive locking of all the parts the entire assembly is heated and rotated at high RPM in a Seasoning plant by the use of a Dynamic Seasoning Mandrel. During this process gap appears at the mating position of Copper-Mica Assembly and Metallic parts due to high centrifugal forces and thermal expansion. After stopping the assembly it is pressed in a press and the bolts are tightened to lock the Metallic parts at its position. This process is repeated again and again till the rotation of the bolts stops.
In the conventional process the Energy consumed is very high as the number of cycles, to achieve a stage when the locking bolts stops rotation, is very high. Due to increased number of times of Seasoning & tightening extra work content of the manpower is required.
Total Clearance between the mating parts during rotation & heating is reduced when it is tightened and locked at the static condition.

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In prior art patents KR920003852 discloses the seasoning furnace with plurality of locks which adjusts the process cycle ,time in accordance with the object to be seasoned which improves the economy of seasoning process, whereas in US4598464 discloses manufacturing of collectors in a single heating cycle under stress with the aid of induction heating. In US Patent no US 1826628 discloses the use of disk spring with uniform pressure around it to cause slow yielding of commutator bars on seasoning.
An object of the invention is to provide an improved & efficient process for the seasoning of the Commutator of DC Motors.
An object of the invention is to reduce the number of the Seasoning Cycle for the Commutator of DC Motors.
An object of the invention is to reduce the number of Pressing Cycle for the Commutator of DC Motors.
An object of the invention is to provide an improved the productivity of the Commutator manufacturing process.
An object of the invention is to reduce the energy consumption during the manufacturing of the Commutator of DC Motors.
An object of the invention is to improve the Quality of the Commutator of DC Motors.

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According to the invention a provision of pressing the Commutator assembly will be provided in the Dynamic Seasoning mandrel which involves a process of mounting of disc spring with Commutator assembly, rotation process at high temperature at High RPM which help to fill the clearance due to stress release by the disc spring.
In accordance with the present invention, can provide many benefits acquired by the help of this invention. Through the provision of pressing in the Dynamic Seasoning mandrel, it is easy to load or press the commutator assembly in a rotating and heated condition.
In accordance with the present invention, maximum clearance arises between the mating parts when the assembly is rotated and heated due to high centrifugal forces and thermal expansion. These clearances and gaps can be eliminated, as the assembly is pressed by a preloaded disc spring mounted (axially) to press the metallic parts.
In accordance with the present invention, the moment any gap appears the preloaded disc spring will release its stress to accommodate the gat created due to high centrifugal forces and thermal expansion.
In accordance with the present invention, any kind of clearance and gaps can be captured & accommodated , when the clearance and gaps are at there peak due to high centrifugal forces and thermal expansion because of the preloaded disc spring. After
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this the bolts are tightened and locked and the entire assembly is pressed on a press to further reduce the clearance and gaps.
In accordance with the present invention, for the next seasoning cycle the disc spring is again preloaded on the same press & mounted in the plant for the next cycle. The same process of Dynamic process takes place.
In accordance with the present invention, pressing & arrest the clearance and gaps due to high centrifugal forces and thermal expansion during the rotation because of the preloaded disc spring will reduce the number of Dynamic Seasoning Cycles as maximum clearance and gaps will be captured during the rotation.
In accordance with the present invention, providing benefits, Due to reduction in number of Dynamic Seasoning Cycles the energy consumed to heat and rotate the commutator is reduced.
In accordance with the present invention, providing benefits, Due to reduction in number of Dynamic Seasoning Cycles the manpower productivity will improve as the no of pressing cycles is reduced.
In accordance with the present invention, providing benefits, Due to uniform pressing during Dynamic Seasoning Cycles the positive locking of the V grooves improves.
In accordance with the present invention, providing benefits, By the use of preloaded Disc spring residual clearance and gaps are reduced.


In accordance with the present invention, providing benefits, Due the reduction in the residual clearance and gaps the positive locking of the V grooves improves and hence the commutator quality improves.