Miniature inductor

• US 4,553,123 A
• Filed: 09/03/1982
• Issued: 11/12/1985
• Est. Priority Date: 09/03/1982
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Tamada, Minoru, Kumokawa, Takashi, Shimamoto, Ichiji
• Primary Examiner(s): EISENZOPF, REINHARD
• Application Number:
  US06/414,666
• Time in Patent Office: 1,166 Days
• Field of Search: 336/83, 336/212, 336/216, 336/221, 336/223, 336/233, 336/192, 140/105, 339/276 R
• US Class Current: 336/83
• CPC Class Codes: H01F 27/292 Surface mounted devices

Abstract

A miniature inductor used as a boosting coil in a piezoelectric buzzer drive circuit or the like is disclosed. The inductor has a closed magnetic circuit core formed of two cores covering the outer periphery of a coil wound around inner coil-cores. A pair of cutout windows are provided at the outer periphery of each of the cores, and joint plates are disposed on the inner bottom surface of one core. Terminal blocks project outwardly therefrom, so that the terminal blocks are adapted to be folded over each other. The end of each lead wire of the coil is guided through the cutout window and sandwiched between the folded terminal blocks, thereby connecting therewith.

Claims

1. An inductor, comprising:

a closed magnetic circuit core comprising an outer core for substantially enclosing a coil space, said outer core having defined therein a plurality of windows;

said closed magnetic circuit core further comprising an inner coil core located in said coil space;

at least one coil in said coil space wound around said inner coil core;

said coil comprising at least one wire having a plurality of lead wires, each lead wire extending out of said coil space through a respective one of said windows; and

a plurality of plates, each plate being mounted to said closed magnetic circuit core and comprising a respective terminal extending outward from a respective one of said windows in said outer core, each said respective terminal having first and second portions and being bendable for holding said respective lead wire between said first and second portions;

each said respective terminal comprising a solder layer on at least one of said first and second portions for being melted when said respective lead wire is held between said first and second portions and for connecting said first and second portions to each other and to said respective lead wire;

said wire of said coil having a heat-meltable coating material for insulating said wire and for melting from said lead wires of said wire when said solder layer of each said terminal is melted.

2. The inductor of claim 1, in which said outer core has a generally flat inner end surface with a perimeter and a wall joining said end surface at said perimeter, said windows being defined in said wall and each said window being defined adjacent said perimeter of said end surface, each said respective plate being disposed adjacent said end surface of said outer core with said respective terminal extending from said respective window.

3. The inductor of claim 2, in which each of said plates comprises a conductive material, said inductor further comprising an insulating material for insulating each of said plates from said end surface of said outer core and from said wall around said respective window defined in said outer core.

4. The inductor of claim 3, in which each of said plates comprises a metallic material.

5. The inductor of claim 1, in which said outer core comprises first and second cores.

6. The inductor of claim 5, in which each of said first and second cores is bowl-shaped.

7. The inductor of claim 5, in which said first core is bowl-shaped and said second core is plate-shaped.

8. The inductor of claim 1, in which said outer core has an outer surface, said second portion of each said terminal being bendable in relation to said first portion, said second portion having an inner end edge disposed inward from said outer surface of said outer core.

9. The inductor of claim 1, further comprising an insulating material for filling each of said windows.

10. The inductor of claim 1, in which each of said plates comprises a metallic material.

11. The inductor of claim 1, in which said coil is adhered by adhesive to said closed magnetic circuit core and in which each plate is adhered by adhesive to said closed magnetic circuit core.