Protection Device

• US 20160086753A1
• Filed: 04/17/2014
• Published: 03/24/2016
• Est. Priority Date: 04/19/2013
• Status: Active Grant

• Current Assignee: Littelfuse Japan G.K. (Littelfuse Incorporated)
• Original Assignee: Tyco Electronics Japan GK (TE Connectivity Ltd. (United Kingdom))
• Inventors: Mochizuki, Hirofumi, Tanaka, Arata
• Granted Patent: US 10,283,295 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01H 2037/5463 the bimetallic snap element forming part of switched circuit
• CPC Class Codes: H01H 2037/5481 the bimetallic snap element being mounted on the contact spring
• CPC Class Codes: H01H 37/34 Means for transmitting heat thereto, e.g. capsule remote from contact member
• CPC Class Codes: H01H 37/46 actuated due to expansion or contraction of a solid deflection of a bimetallic element H01H37/52
• CPC Class Codes: H01H 37/52 actuated due to deflection of bimetallic element
• CPC Class Codes: H01H 37/5427 encapsulated in sealed miniaturised housing

Abstract

The present invention provides a protection device comprising a bimetal component and a PTC component. This protection device comprises a resin base, a first terminal, a second terminal, a PTC component, a bimetal component, an arm, an upper plate and a resin cover wherein

• • a portion of the first terminal configures a first electrode, and a portion of a second terminal configures the second electrode,
  • the first electrode and the second electrode are exposed outward at the bottom surface of the resin base,
  • in a normal state, the first terminal, the arm and the second terminal are electrically connected in series,
  • when the bimetal component is activated, the first terminal and the arm become to be electrically cut off while the first terminal, the PTC component, the bimetal component, the arm and the second terminal are electrically connected in series in thus mentioned order.

Claims

1. A protection device comprising a resin base, a first terminal, a second terminal, a PTC component, a bimetal component, an arm, an upper plate and a resin cover, wherein

a portion of the first terminal configures a first electrode, and a portion of a second terminal configures the second electrode,

the first electrode and the second electrode are exposed outward at the bottom surface of the resin base,

in a normal state, the first terminal, the arm and the second terminal are electrically connected in series, and

when the bimetal component is activated, the first terminal and the arm becomes electrically cut off while the first terminal, the PTC component, the bimetal component, the arm and the second terminal are electrically connected in series in the mentioned order.

2. The protection device according to claim 1, characterized in that the bimetal component has been subjected to heat-treatment.

3. The protection device according to claim 2, characterized in that the temperature of heat-treatment is higher than a temperature of soldering the protection device.

4. The protection device according to claim 1, characterized in that the first terminal and/or the arm has a contact part, and at least one of these contact parts is formed by swaging a contact material through the first terminal and/or the arm.

5. The protection device according to claim 4, characterized in that the contact material is a silver-nickel alloy.

6. The protection device according to claim 1, characterized in that at least a part of the first terminal has a rib.

7. The protection device according to claim 1, characterized in that the resin base is formed from a thermal resistant resin.

8. The protection device according to claim 1, characterized in that the upper plate has an engaging part having a hook-like shape and is fixed on the resin base by engaging the engaging part to an engaged part having a notch shape of the resin base.

9. The protection device according to claim 1, characterized in that the arm has a crank shape portion in the space of the resin base.

10. The protection device according to claim 1, characterized in that the bimetal component has a protrusion near its center portion.

11. The protection device according to claim 1, characterized in that the exposed portions of the first terminal and/or the second terminal are plated with a metal unsusceptible to oxidation.

12. The protection device according to claim 11, characterized in that the metal unsusceptible to oxidation is gold.

13. The protection device according to claim 1, characterized in that the first electrode and the second electrode are provided so as to be line-symmetric with respect to a center line between the first electrode and the second electrode at the bottom surface of the resin base.

14. A protection device comprising a bimetal component and protecting a circuit by the activation of the bimetal component, characterized in that the bimetal component has been subjected to heat-treatment.

15. The protection device according to claim 14, characterized in that temperature of the heat-treatment is higher than a temperature of soldering the protection device.