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
Superconductor coil winding former
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTORS
Dixit Manglesh and Sathe Mahesh, of CG Global R&D Centre, Crompton Greaves Ltd., Kanjur (E), Mumbai 400042, Maharashtra, India, both Indian Nationals
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention:

FIELD OF THE INVENTION
This invention relates to an improved superconductor coil winding former.
BACKGROUND OF THE INVENTION
In prior art various types of conventional winding formers are available for conventional winding, however for superconductor winding special kind of formers are used. Since, the superconductor operates in cryogenic temperature at 77 Kelvin and therefore the superconductor needs effective cooling. In this regard, a corrugated former is designed providing the corrugation on the GFRP or Teflon or former.
In conventional windings, from manufacturing ease point of view and cryogenic feasibility have always adopted corrugated wrap up, over the cylindrical former which were feasible as edge strip at the end of the winding and before start of the winding. This will be angular to cylindrical former and matching with end faces of the former was holding the winding coil and as well as corrugated former and adjusting the lateral coil length when the winding was held vertical. But the same was not feasible in case of delicate HTS superconducting tape winding, as incorporation of edge strips is not advisable from HTS tape life. Due to this holding of corrugated wrap up was not possible and needs to eliminate corrugated wrap up from the winding design of HTS superconductor tape after such elimination.
With conventional winding, winding turn lateral adjustment is required to maintain the required winding coil length and was undesirable from superconducting tape performance and life. New design reduces the frictional grip between winding coil


and former by reducing the area of contact and makes the lateral adjustment possible with least minimum force and reduces the risk of tape manufacturers winding performance and tape life getting affected.
Conventional rectangular grooved formers have sharp edges that may create localized bending at particular points in the winding that in turn suppresses the current carrying capacity of the conductor and even can result in local burnout. In the present design curved grooves were provided that has benefits of no sharp edges, to prevent any damage to the conductor and it will get more surface area for cooling.
OBJECTS OF INVENTION
An object of the invention is to provide vertical corrugation curved groves at equal distances on the former.
Another object of the invention is to provide the benefit of effective cooling to the coil from inner part attached to the former.
Another object of the invention is to provide curved grooves to ensure the superconductor tape in the coil will not undergo any kind of localised bending or kinks and thereby to maintain its actual current carrying capacity.
Another object of the invention is to provide curved grooves as above, to provide more surface area of superconductor tape to get exposed to cryogenic fluid as compared to the flat rectangular grooves.


Another object of the invention is to provide helical projection over the corrugation so as to have the coil's track benefit of winding support.
DETAILED DESCRIPTION
The Former is a FRP or Plastic or Teflon component with vertical corrugated grooves cut on periphery of former for allowing liquid nitrogen to flow easily adjacent to inner surface from the first layer of winding on the former. The former supports the winding and reduces the contact area with winding layer, enhance cooling and thereby allows easy lateral adjustment of winding turns to maintain the required coil length and avoids possible damages to delicate super conductor tape, which is undesirable for the winding material performance.
In addition to above the vertical corrugated grooves edges form a winding start point and end point and avoids any markings on the former which sometimes during winding remain on former and becomes cause of making liquid nitrogen bath impure after the marking ink mixes with liquid nitrogen.
The vertical corrugation grooves are curved type and therefore ensures no damage to the conductor and also provides the more cooling surface to the superconductor tape compared to the flat rectangular grooves.
Conventional normal cylindrical former with conventional horizontal winding technique, could not provide effective cooling from inner surface, and due to the need of having a former that shall support the winding properly during transit.


According to the present invention, vertical corrugation curved grooves provided at equal distances on the former.
In accordance to the present invention, is to provide the benefit of effective cooling to the coil from inner part wound to the former.
In accordance to the present invention, is to provide curved grooves to prevent the superconductor tape in the coil from undergoing any kind of localised bending or kinks, and to maintain its desired current carrying capacity.
In accordance to the present invention, is to provide curved grooves as above, thereby to provide more surface area to the superconductor tape for getting exposed to cryogenic fluid.
According to another embodiment of the present invention, is to provide helical projection over the corrugation to get the coil's track benefit of winding support.
Dated this 28th day of March 2008.
Crompton Greaves Limited By their Agent & Attorney