Electric coil device for use as a transformer or the like

• US 5,293,146 A
• Filed: 06/03/1991
• Issued: 03/08/1994
• Est. Priority Date: 06/08/1990
• Status: Expired due to Fees

• Current Assignee: Totoku Electric Company Limited (Furukawa Electric Company Limited), Sanken Electric Company Limited
• Original Assignee: Totoku Electric Company Limited (Furukawa Electric Company Limited), Sanken Electric Company Limited
• Inventors: Yamaguchi, Tadashi, Aosaki, Yoshiki
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Horgan, Christopher
• Application Number:
  US07/709,481
• Time in Patent Office: 1,009 Days
• Field of Search: 336/206, 336/846, 336/205, 336/222, 174/120 R, 174/120 AR, 174/120 SR, 174/110 N, 174/110 R, 428/371, 428/377, 428/906, 156/53, 156/56
• US Class Current: 336/206
• CPC Class Codes: H01F 27/323 Insulation between winding turns, between winding layers
• CPC Class Codes: Y10S 174/25 Transformer
• CPC Class Codes: Y10S 174/26 having a plural-layer insulation system
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]

Abstract

A transformer is disclosed which has a primary and a secondary winding disposed concentrically around a core via a flanged bobbin. Each winding has a conductor wire which is doubly or, preferably, triply sheathed with insulating tapes of different widths. The first or inmost insulating tape is wound overlappingly in a first direction around the conductor wire without being bonded thereto. The second or intermediate insulating tape, less in width than the first, is wound overlappingly in a second direction, opposite to the first direction, over the first insulating tape and bonded thereto via a preformed adhesive layer on the second insulating tape. The third or outmost insulating tape, still less in width than the second, is wound overlappingly in the first direction over the second insulating tape and bonded thereto via a preformed adhesive layer on the third insulating tape. The ratio of the overlap of each tape to the tape width becomes progressively less from the inmost toward the outmost tape. With the conductor wires of the two concentric windings thus individually insulated, no additional insulations are required for the transformer.

Claims

1. An electric coil device having a winding around a core, the winding comprising:

(a) a conductor wire;

(b) a first insulating tape of predetermined width wound in a first direction and with an overlap of predetermined width around the conductor wire, the first insulating tape being not bonded to the conductor wire;

(c) a second insulating tape having a width less than the width of the first insulating tape and wound in a second direction, opposite to the first direction, and with an overlap around the conductor wire via the first insulating tape, the ratio of the width of the overlap of the second insulating tape to the width of the second insulating tape being less than the ratio of the width of the overlap of the first insulating tape to the width of the first insulating tape, the second insulating tape being bonded to the first insulating tape; and

(d) a third insulating tape having a width less than the width of the second insulating tape and wound in the first direction and with an overlap around the conductor wire via the first and the second insulating tapes, the ratio of the width of the overlap of the third insulating tape to the width of the third insulating tape being less than the ratio of the width of the overlap of the second insulating tape to the width of the second insulating tape, the third insulating tape being bonded to the second insulating tape.

2. The electric coil device of claim 1 wherein the ratio of the overlap of the first insulating tape to the width of the first insulating tape is greater than 0.5, and wherein the ratio of the overlap of the third insulating tape to the width of the third insulating tape is less than 0.5.

3. The electric coil device of claim 1 wherein the first insulating tape has no preformed adhesive layer on either side thereof, wherein the second insulating tape is bonded to the first insulating tape via an adhesive layer preformed on one side of the second insulating tape, and wherein the third insulating tape is bonded to the second insulating tape via an adhesive layer preformed on one side of the third insulating tape.

4. An electric coil device having at least two windings disposed concentrically around a core, each winding comprising:

(a) a conductor wire;

(b) a first insulating tape of predetermined width wound in a first direction and with an overlap of predetermined width around the conductor wire, the first insulating tape being not bonded to the conductor wire;

(c) a second insulating tape having a width less than the width of the first insulating tape and wound in a second direction, opposite to the first direction, and with an overlap around the conductor wire via the first insulating tape, the ratio of the width of the overlap of the second insulating tape to the width of the second insulating tape being less than the ratio of the width of the overlap of the first insulating tape to the width of the first insulating tape, the second insulating tape being bonded to the first insulating tape; and

(d) a third insulating tape having a width less than the width of the second insulating tape and wound in the first direction and with an overlap around the conductor wire via the first and the second insulating tapes, the ratio of the width of the overlap of the third insulating tape to the width of the third insulating tape being less than the ratio of the width of the overlap of the second insulating tape to the width of the second insulating tape, the third insulating tape being bonded to the second insulating tape;

(e) whereby, as the conductor wires of the two windings are individually insulated with the first and the second and the third insulating tapes, no additional insulation means such as insulating paper is required between the two windings.

5. An electric coil device having two windings disposed concentrically all over the surface of a bobbin having a pair of flanges on its opposite ends, one of the flanges having two pairs of terminal pieces thereon, each winding comprising:

(a) a conductor wire having a pair of opposite end portions electrically connected to one pair of terminal pieces on one of the bobbin flanges;

(b) a first insulating tape of predetermined width wound in a first direction and with an overlap of predetermined width around the conductor wire without being bonded thereto, the width of the overlap of the first insulating tape being more than half the width of the first insulating tape;

(c) a second insulating tape having a width less than the width of the first insulating tape and wound in a second direction, opposite to the first direction, and with an overlap around the conductor wire via the first insulating tape, the second insulating tape being bonded to the first insulating tape, the ratio of the width of the overlap of the second insulating tape to the width of the second insulating tape being less than the ratio of the width of the overlap of the first insulating tape to the width of the first insulating tape; and

(d) a third insulating tape having a width less than the width of the second insulating tape and wound in the first direction and with an overlap around the conductor wire via the first and the second insulating tapes, the width of the overlap of the third insulating tape being less than half the width of the third insulating tape, the ratio of the width of the overlap of the third insulating tape to the width of the third insulating tape being less than the ratio of the width of the overlap of the second insulating tape to the width of the second insulating tape, the third insulating tape being bonded to the second insulating tape;

(e) whereby, as the conductor wires of the two windings are individually insulated with the first and the second and the third insulating tapes, no additional insulation means such as insulating paper is required between the two windings, and, being not bonded to the conductor wires, the first and the second and the third insulating tapes can be readily stripped from the opposite end portions of each conductor wire for their electrical connection to the terminal pieces.

6. The electric coil device of claim 5 wherein the width of the overlap of the first insulating tape of each winding is more than two thirds of the width of the first insulating tape.