Encased transformer

• US 5,034,854 A
• Filed: 05/29/1990
• Issued: 07/23/1991
• Est. Priority Date: 06/01/1989
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsuda, Masayoshi, Kuniya, Yoshihiro, Matsumura, Katsumi, Ishikawa, Kazunari, Hirooka, Yutaka
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US07/529,915
• Time in Patent Office: 420 Days
• Field of Search: 336/65, 336/92, 336/96, 336/192, 336/198, 336/208, 361/405, 361/395, 361/396
• US Class Current: 361/744
• CPC Class Codes: H01F 27/292 Surface mounted devices

Abstract

An encased transformer that comprises a bobbin including a plastic-molded cylindrical portion and upper and lower collars formed respectively at upper and lower ends of the cylindrical portion, a magnetic element extending centrally through the cylindrical portion, primary and secondary coils wound round the outer periphery of the cylindrical portion, comb-shaped metals terminal formed on the pair of lower collars by insert molding, the comb-shaped portion of each metal terminal being bent at generally right angles, the metal terminals being further bent at right angles and outwardly horizontally at an end portion thereof so that the metal terminal is substantially Z-shaped, a straight portion of the metal terminal positioned midways of the Z-shaped being fixedly held in position between the inner wall of a case and a frame wall having recessed terminal grooves into which are individually fitted metal terminals provided in a plastic square bottom plate.

Claims

1. An encased transformer comprising a bobbin including a plastic-molded cylindrical portion and upper and lower collars formed respectively at upper and lower ends of the cylindrical portion, a magnetic element extending centrally through the cylindrical portion, primary and secondary coils wound round the outer periphery of the cylindrical portion, comb-shaped metal terminals formed on the pair of lower collars by inert molding, the comb-shaped terminals each having a substantially U-shaped portion with first and second legs being bent at generally right angles, the first legs each being further bent at right angles and outwardly horizontally at an end portion in a substantially Z-shape, a straight portion positioned midway of the z-shape end portion being fixedly held in position between an inner wall of a case and a frame wall having recessed terminal grooves into which are individually fitted said Z-shape end portion and said frame wall mounted on a plastic square bottom plate.

2. An encased transformer according to claim 1, wherein said bobbin, magnetic elements and coils are embedded, at least in part, in a resin having a degree of hardness of from 20 to 50, the bottom plate being fitted in position through an opening of the case.

3. An encased transformer according to claim 1, wherein the case is provided with an undercut portion in its interior, said bottom plate formed with an engaging projection being fitted in position so that the engaging projection goes into engagement with the undercut portion of the case, and wherein the size of the bottom plate is at least as large as the size of the opening of the case, the case being positioned on the bottom plate, and the underside of the bottom plate being flush with the bottom of the Z-shape end portion.

4. An encased transformer according to claim 1, wherein the bottom plate has an electronic circuit formed by various electronic parts thereon, the bottom plate being fitted in position so that the electronic circuit is positioned with the opening of the case, the circuit being thereby electrically connected to the comb-shaped terminals.