Compact inductor

• US 4,064,472 A
• Filed: 04/08/1976
• Issued: 12/20/1977
• Est. Priority Date: 04/08/1976
• Status: Expired due to Term

• Current Assignee: Vanguard Electronics Company Incorporated
• Original Assignee: Vanguard Electronics Company Incorporated
• Inventors: Glick, Leslie P., Sakihara, Yoshinobu F., Gunewardena, Shelly J.
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US05/674,758
• Time in Patent Office: 621 Days
• Field of Search: 336/192, 336/65, 336/96, 336/92, 338/269, 338/275, 338/322, 174/52 PE, 264/274
• US Class Current: 336/65
• CPC Class Codes: H01F 17/045 with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder

Abstract

A miniature inductor comprising a sheet metal frame having a slot that divides the frame into two separated halves, each half having a pair of upstanding tabs and a pair of inclined tapered flanges. A plate of insulating material extends across the slot and is held in position by the tabs, while a bobbin lies on the insulator and has its ends attached to the flanges. A mass of plastic encapsulates all of the components except for the bottom surfaces of the frame halves which serve as terminals.

Claims

1. An inductor comprising:

a flat frame of sheet metal having a mount slot extending thereacross to divide the frame into two separated frame halves;

each frame half having upper and lower surfaces and a pair of upstanding tabs lying at the edge of said slot, the two tabs of each pair being spaced a predetermined distance apart, and each frame half having a partially upstanding flange which is spaced from the slot and which is tapered in width with the top being of greatest width and which extends at less than 90°

from the plane of the frame;

a plate of insulating material extending across said slot and having a pair of legs, each leg received between a pair of tabs;

a bobbin which includes a coil of electrically conductive wire wound on a spool, said bobbin being mounted on said insulator, and the ends of said wire being attached to different ones of said flanges, the top of each flange being spaced from said coil to leave a space between them; and

a mass of electrically insulative encapsulating material disposed about said bobbin, said flanges, said tabs, and said insulator, but the bottom surfaces of each frame half being exposed for the making of electrical connection thereto.

2. An inductor comprising:

a frame of sheet metal having a mount slot dividing the frame into two separated portions, and having a pair of upstanding spaced tabs on opposite sides of the slot;

an insulator disposed on said frame and extending across said mount slot, said insulator comprising a plate having a leg on each side thereof, with each of said legs received between a pair of said tabs;

a coil assembly disposed on said insulator and lying over said mount slot, said coil having two leads attached to portions of said frame which lie on opposite sides of said mount slot; and

nonmagnetic and electrically insulative molding material encapsulating said coil assembly and at least part of said frame to hold them together.

3. The inductor described in claim 2 wherein:

said insulator has four legs, all of substantially the same width; and

the space across said slot, between the two pairs of tabs is substantially equal to the distance between the two tabs of each pair of tabs, whereby the insulator can be installed in any of four orientations.

4. Apparatus for use in constructing inductors, comprising:

a strip-shaped lead frame formed of a strip of metal, said frame having a plurality of mount holes spaced therealong and having at least one spacer hole lying between each pair of mount holes, said frame having a plurality of bent-up tabs extending from opposite sides of said mount holes, and said frame having a bent-up flange extending into each of said spacer holes;

a plurality of insulators, each received over a mount hole and against a bent-up tab;

a plurality of coil assemblies, each disposed on one of said insulators; and

a plurality of masses of substantially nonmagnetic and electrically insulative encapsulating material, each disposed about a coil assembly, insulator, a pair of tabs, and a flange.

5. The apparatus described in claim 4 wherein:

each flange extends at an angle of less than 90°

from the plane of said strip-shaped frame, and is tapered in width with its top wider than its bottom, whereby to securely hold the encapsulating material to the frame.