DILIP M PUROHIT, MD
Medical Practice at Ashley Ave, Charleston, SC

6806803, Oct 19, 2004

Dec 6, 2002

10/313547

Philip J. Hopkinson - Charlotte NC
Dilip R. Purohit - Charlotte NC
Gary D. King - Laurel MS

Square D Company - Palatine IL

H01F 2706

336 67, 336 65, 336 5, 336 12

An electrical transformer is disclosed. The electrical transformer comprises a central axis, a first modular section, and a second modular section. The first modular section is positioned about the central axis and comprises a first support, a first winding of a conductive element, and a first insulating material. The first winding of a conductive element is located about the first support. The first insulating material covers a portion of the first modular section. The second modular section is axially aligned with the first modular section and electrically connected to the first modular section. The second modular section comprises a second support, a second winding of a conductive element, and a second insulating material. The second winding of a conductive element is located about the second support. The second insulating material covers a portion of the second modular section.

6368530, Apr 9, 2002

Dec 16, 1999

09/465080

John D. Adubato - Monroe NC
Dilip R. Purohit - Charlotte NC
Scott F. Lett - Monroe NC
Richard R. Rettew - Fort Mill SC

Square D Company - Palatine IL

B28B 148

264154, 2642722, 264294, 26427219, 29605, 29606

An improved method for creating cooling ducts in cast resin coils uses uniform cross section thermoplastic tooling segments. These segments are wound into windings between predetermined layers or radial sections, oriented parallel to the coil axis. They extend through the height of the coil. After the coil is cast, impregnated, or saturated with resin, and the resin is cured, the segments are withdrawn. The removal of a segment results in a continuous cooling duct. The thermoplastic segments are either solid machined from sheet or extruded with thin outer walls. Extrusion allows for uniform cross section relatively long somewhat flexible segments, which will cause the radius of curvature of the segment to conform to the shape of the coil due to the tension from the conductor and reinforcing material during the winding process. This will have the result of reducing the number of different segment designs required to support production of a variety of different diameter coils. Elliptical or similar shaped coils with conforming cooling ducts are possible from the same segment design.

5396210, Mar 7, 1995

Mar 17, 1993

8/032954

Dilip R. Purohit - Charlotte NC
Timothy A. Soter - Monroe NC
Jeewan Puri - Matthews NC

Square D Company - Palatine IL

H01F 2708

336 60

A dry type transformer has an iron core, high voltage windings embedded in cast resin, and low voltage windings resin encapsulated. The low voltage winding is constructed with flexible sheet conductors. Insulating material includes an apparatus to secure the windings in place during a vacuum and pressure resin impregnation process. The result is a coil that exhibits high short circuit protection due to the tightly bond conductors comparable to completely resin encased molded transformers at a substantially reduced cost.

5621372, Apr 15, 1997

Sep 20, 1994

8/309380

Dilip R. Purohit - Charlotte NC

Square D Company - Palatine IL

H01F 2708

336 60

A single phase, dry type transformer has an iron core, high voltage windings embedded in cast resin, and low voltage windings resin encapsulated. The low voltage winding is constructed with flexible sheet conductors. Insulating material includes a means to secure the windings in place during a vacuum and pressure resin impregnation process. The result is a coil that exhibits high short circuit protection due to the tightly bond conductors comparable to completely resin encased molded transformers at a substantially reduced cost.

5267393, Dec 7, 1993

Mar 17, 1993

8/032371

Dilip R. Purohit - Charlotte NC
Timothy A. Soter - Monroe NC

Square D Company - Palatine IL

H01F 4106

29605

A dry type transformer has an iron core, high voltage windings embedded in cast resin, and low voltage windings resin encapsulated. The low voltage winding is constructed with flexible sheet conductors. Insulating material includes a means to secure the windings in place during a vacuum and pressure resin impregnation process. A unique cylinder or mandril provides a flat surface for one of the low voltage external leads to rest on during the start of the coil winding process. Cooling duct sizes and locations in the windings are varied during winding. The result is a finished coil that maintains an essentially cylindrical shape.

6278355, Aug 21, 2001

Aug 23, 1999

9/378786

Philip J. Hopkinson - Charlotte NC
Dilip R. Purohit - Charlotte NC
Gary D. King - Matthews NC

Square D Company - Palatine IL

H01F 2728

336225

A transformer including a core having first and second portions, and first and second primary winding sections. The first primary winding section includes a plurality of winding layers (L. sub. 1 -L. sub. n) about the first portion of the core, and the second primary winding section includes a plurality of winding layers (L. sub. 1 -L. sub. n) about the second portion of the core. Corresponding winding layers of the first and second winding sections are separated by a distance (D. sub. 1 -D. sub. n). The distance (D. sub. 1 -D. sub. n) between the corresponding layers of first and second primary winding sections increases as the number of winding layers (L. sub. 1 -L. sub. n) increases.