# US 4,393,364 A · Coil element

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- Number: US 4,393,364 A
- Document ID: US4393364A
- Status: Granted
- Kind: A
- Application number: 06/300,456
- Filed: 1981-09-08
- Granted: 1983-07-12
- Earliest claimed: 1980-09-19
- Assignees: TDK Electronics Co., Ltd.
- Inventors: Takayuki Suda; Koichi Yasuda
- Web page: https://patentgrep.com/patent/US4393364A

## CPC

- H01F 3/10: Composite arrangements of magnetic circuits
- H01F 5/00: Coils (superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00)
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

A coil element formed from a drum-shaped ferrite core on which a coil is wound, magnetic members each made of a magnetic and electrically conductive metal and formed so as to fit to the outer surface of the drum-shaped ferrite core and spaced from each other so as to be electrically insulated from each other, and connection terminals forming a part of the magnetic members connected to the ends of the coil.

## Claims

### Claim 1

A coil element comprising a drum-shaped ferrite core on which a coil is wound, magnetic members each made of a magnetic and electrically conductive metal and formed so as to fit to the outer surface of said drum-shaped ferrite core and spaced from each other so as to be electrically insulated from each other, and connection terminals forming a part of said magnetic members connected to the ends of said coil.

### Claim 2 (depends on 1)

A coil element as in claim 1, in which each magnetic member is of a cross-sectional shape that is arcuate.

### Claim 3 (depends on 2)

A coil element as in claim 2, in which there are two of said magnetic members each of arcuate length less than a half-circle.

### Claim 4 (depends on 2, 3)

A coil element as in claim 2 or 3, in which the radius of curvature of the arc of each of said magnetic members is slightly less than that of said drum-shaped ferrite core.