# US 4,400,674 A · Coil unit

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- Number: US 4,400,674 A
- Document ID: US4400674A
- Status: Granted
- Kind: A
- Application number: 06/185,526
- Filed: 1980-09-09
- Granted: 1983-08-23
- Earliest claimed: 1980-04-22
- Assignees: TDK Electronics Co., Ltd.
- Inventors: Takayuki Suda; Koichi Yasuda
- Web page: https://patentgrep.com/patent/US4400674A

## CPC

- H01F 17/043: {with two, usually identical or nearly identical parts enclosing completely the coil (pot cores)}
- H01F 17/045: {with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core}
- H05K 1/182: associated with components mounted in printed circuit boards [PCB], e.g. insert-mounted components [IMC]
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

A coil unit formed of a coil-wound inner core partially circumferentially encased by an outer core. The coil unit is mounted on a plate with the outer core externally exposed and covering the lead-in wires to the coil which are adhered to contacts on the plate.

## Claims

### Claim 1

A coil unit comprising an outer core in the form of about a half cylinder, and a drum-shaped bobbin core provided with a flange on each end thereof and having a coil wound thereon, said outer core and said bobbin core being assembled with a part of the outer periphery of said flanges fixed to the inner periphery of said outer core and with the outer core encasing the bobbin core for only about one-half the circumference of said bobbin core, the remainder of said bobbin core being non-encased.

### Claim 2 (depends on 1)

A coil unit as set forth in claim 1, wherein electrode plates are provided on said outer core.

### Claim 3 (depends on 1)

A coil unit as set forth in claim 1, wherein metallic caps are provided on said outer core.

### Claim 4

A coil unit comprising an outer core and an inner core, said inner core having a coil wound thereon, and said outer core being positioned against and partially circumferentially encasing said coil-wound inner core for only about one-half the circumference of said inner core, the remainder of said coil-wound inner core being non-encased.

### Claim 5 (depends on 4)

A coil unit as set forth in claim 4, in combination with a mounting plate having an opening therein into which said non-encased part of said coil-wound inner core is positioned.

### Claim 6 (depends on 4)

A coil unit as set forth in claim 4, wherein said inner core includes a flange on each end thereof, and in combination with a mounting plate having one or more openings therein into which said flanges are positioned.

### Claim 7 (depends on 5, 6)

A coil unit as set forth in claim 5 or 6, wherein said mounting plate includes electrodes thereon electrically connected to said coil and positioned beneath said outer core.