METHOD OF MAKING A RANDOM WOUND ENCAPSULATED COIL

• US 3,662,460 A
• Filed: 10/20/1970
• Issued: 05/16/1972
• Est. Priority Date: 08/08/1967
• Status: Expired due to Term

• Current Assignee: Thomas J. Daley
• Original Assignee: Thomas J. Daley
• Inventors: Daley, Thomas J.
• Primary Examiner(s): Campbell, John F.
• Assistant Examiner(s): Hall, Carl E.
• Application Number:
  US05/082,444
• Time in Patent Office: 574 Days
• Field of Search: 29/605,602 336/96,198,205,208
• US Class Current: 29/605
• CPC Class Codes: H01F 41/10 Connecting leads to windings making electric connections in general H01R43/00
• CPC Class Codes: H01F 41/127 Encapsulating or impregnating encapsulating coil and core H01F41/005
• CPC Class Codes: H01F 5/02 wound on non-magnetic supports, e.g. formers
• CPC Class Codes: Y10T 29/49071 by winding or coiling

Abstract

A random winding is located on a spool having a central support and having end flanges provided with ribs or perforations. An insulating material in fluid form such as an epoxy resin is applied under pressure to the winding and spool to flow between the ribs or through the perforations to compact the winding. This provides a continuous layer of the insulant in contact with end windings and assures good resistance to electric breakdown. Insulant may be introduced in a similar way between the central spool support and the winding.

Claims

1. The method of constructing an encapsulated coil assembly which comprises constructing a unit including a spool having a central support and a flange at a first end of the support, winding turns of a coil around the central support with end turns of the coil touching at least a portion of said flange and with substantial portions of the end turns exposed to the exterior of said coil and spool, moving said end turns away from said flange in a direction parallel to the longitudinal axis of said spool such that said end turns are in a spaced relationship with said flange, and securing said coil and said end turns when in said spaced relationship to said spool.

2. The method claimed in claim 1 wherein said step of winding exposes substantial portions of the end turns to the exterior of said coil and spool unit, and said moving comprises the step of flowing under pressure a hardenable liquid insulating material between said end turns and said flange to mold said insulating material in intimate engagement with said end turns, whereby upon hardening said insulating material forms a continuous solid insulating layer intermediate said end turns and the flange.

3. The method of claim 2 wherein said liquid insulating material is flowed and subjected to pressure over the exposed surface of said coil to encapsulate the coil, said flowing under pressure compressing the coil turns.

4. The method of claim 3 wherein said winding of turns spaces the turns from substantial portions of the central support to permit introduction therebetween of said insulating material, said flowing step being effective for forcing said insulating material between the turns and said central support in intimate engagement with said turns.

5. The method of claim 2 wherein said central support comprises a tubular member, and said spool has a flange at a second end of the support, each of said flanges having plural perforations extending through the flange parallel to said tubular member, said flowing including the flowing under pressure of the insulating material from the exterior of said spool through said perforations to compress the coil.

6. The method of claim 1 wherein said spool has a second flAnge at a second end of the support, said winding step positioning end turns of the coil adjacent the second flange, said moving step spacing said end turns from the second flange.

7. The method of claim 6 wherein said step of winding exposes substantial portions of the end turns adjacent each of the flanges to the exterior of said coil and spool unit, and said moving comprises the step of flowing a hardenable liquid insulating material between each of said flanges and the adjacent end turns under a pressure sufficient to compress the coil turns and to mold a continuous layer of said insulating material into intimate engagement with the end turns adjacent each of the flanges, whereby upon hardening said insulating material forms a solid continuous insulating layer intermediate each of said flanges and the adjacent end turns.

8. The method of claim 7 wherein said winding step is random winding, and each of said flanges has an irregular surface engaging portion of the adjacent end turn surface and exposing other portions of such adjacent end turn surface, whereby said liquid insulating material flows into engagement with the exposed other portions and under pressure forces the end turns away from the flanges.