Protection element

• US 8,803,652 B2
• Filed: 01/14/2010
• Issued: 08/12/2014
• Est. Priority Date: 01/21/2009
• Status: Active Grant

• Current Assignee: Dexerials Corporation
• Original Assignee: Dexerials Corporation
• Inventors: Kimura, Yuji, Asada, Takahiro, Suzuki, Kazuaki
• Primary Examiner(s): THOMAS, BRADLEY H
• Application Number:
  US13/145,455
• Publication Number:
  US 20120249283A1
• Time in Patent Office: 1,671 Days
• Field of Search: 337/416, 337/186, 337/398, 337/297, 296/23, 361/104
• US Class Current: 337/186
• CPC Class Codes: H01H 1/5805 Connections to printed circuits for slide switches H01H15/005; for tumbler switches H01H23/006
• CPC Class Codes: H01H 2037/768 characterised by the composition of the fusible material
• CPC Class Codes: H01H 37/761 with a fusible element forming part of the switched circuit H01H37/767 takes precedence
• CPC Class Codes: Y10T 29/49107 Fuse making

Abstract

A protection element is provided which is capable of stably retaining a flux on a soluble conductor at a predetermined position, enabling a speedy and precise blowout of the soluble conductor in the event of an abnormality. This protection element includes: a soluble conductor 13 which is disposed on an insulation baseboard 11 and is connected to a power supply path of a device targeted to be protected, to cause a blowout by means of a predetermined abnormal electric power; a flux 19 which is coated onto a surface of the soluble conductor 13; and an insulation cover 14 which is mounted on the baseboard 11 with the soluble conductor 13 being covered therewith. In addition, the protection element is provided with a protrusive stripe portion 20 which is formed on an interior face of the insulation cover 14 in opposite to the soluble conductor 13 and in which a stepped portion 20a for retaining the flux 19 is formed at a predetermined position while in contact with the flux 19. The soluble conductor 13 has a hole portion 13a at which the flux 19 is retained.

Claims

1. A protection element for protecting a device to be protected, the protection element comprising:

an insulation baseboard;

a pair of electrodes provided at both ends of a top face of the insulation baseboard;

a low-melting metal conductor which is disposed on the insulation baseboard, and which is adapted to be connected to a power supply path of the device to be protected, wherein the low-melting metal conductor is adapted to cause a blowout by means of a predetermined abnormal electric power, and the protection element is adapted to allow the low-melting metal conductor to blow out and shut off a current path thereof if the abnormal electric power is supplied to the device to be protected;

an insulation cover which is mounted on the baseboard so as to cover the low-melting metal conductor with a predetermined space therebetween;

a flux which is applied to a surface of the low-melting metal conductor and is positioned in the space;

a stepped portion which is formed on a center part of an interior face of the insulation cover opposite to the low-melting metal conductor, for retaining the flux at a predetermined position in the space in direct physical contact with the flux,

wherein the flux is retained at the predetermined position in the space in direct physical contact with the stepped portion due to its wettability and surface tension,

wherein the insulation cover mounted on the insulation baseboard is formed in a box shape which opens at one side face,

wherein a hole portion retaining the flux is formed in the low-melting metal conductor, the hole portion being a through hole formed at a center part of the low-melting metal conductor, the flux being positioned on the low-melting metal conductor so as to be in direct physical contact with at least a peripheral surface of the hole portion so as to be retained at the hole portion due to its wettability and surface tension, and

wherein the stepped portion is concentrically circular and comprises a cylindrical protrusive stripe portion which is formed on the interior face of the insulation cover integrally therewith and is provided face-to-face opposite to the hole portion of the low-melting metal conductor.

2. The protection element according to claim 1, wherein a protrusive portion is formed along a peripheral edge part on the peripheral surface of the hole portion at the center part of the low-melting metal conductor.

3. The protection element according to claim 1, wherein a relatively small hole portion is formed in the low-melting metal conductor at a portion other than the center part of the low-melting metal conductor.

4. The protection element according to claim 1, wherein a number of small hole portions are formed in the low-melting metal conductor.

5. The protection element according to claim 1, wherein an opening portion which is a through hole is formed inside of the stepped portion of the insulation cover.

6. The protection element according to claim 1, wherein a protrusion height of the protrusive stripe portion from the interior face of the insulation cover is set such that a surface of the flux coated onto the low-melting metal conductor comes into direct physical contact with the protrusive stripe portion and such that the flux is retained at the center part of the low-melting metal conductor due to its wettability and surface tension.