# US 12,224,139 B2 · Breaker and safety circuit equipped with the same, and secondary battery pack

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,224,139 B2
- Document ID: US12224139B2
- Status: Granted
- Kind: B2
- Application number: 18/248,753
- Filed: 2021-10-18
- Published: 2023-12-14
- Granted: 2025-02-11
- Earliest claimed: 2020-10-19
- Assignees: Bourns, Inc.
- Applicants: Bourns KK
- Inventors: Masashi Namikawa
- Web page: https://patentgrep.com/patent/US12224139B2

## CPC

- H01H 37/5427: {encapsulated in sealed miniaturised housing}
- H01M 50/581: in response to temperature
- H01M 2200/101: Bimetal
- Y02E 60/10: Energy storage using batteries
- H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A breaker comprises: a first terminal piece on which a fixed contact is formed; a movable piece having a movable contact, for pressing the movable contact against the fixed contact so as to contact therewith; a thermally-actuated element deforming with a change in temperature and moving the movable piece so that the movable contact is separated from the fixed contact, and a second terminal piece electrically connected to the movable piece. The movable piece is provided, within a contact portion contacting with the second terminal piece, with a protrusion projecting toward the thermally-actuated element.

## Claims

### Claim 1

A breaker comprising:
a first terminal piece on which a fixed contact is formed;
a movable piece having a movable contact, for pressing the movable contact against the fixed contact so as to contact therewith;
a thermally-actuated element deforming with a change in temperature and moving the movable piece so that the movable contact is separated from the fixed contact; and
a second terminal piece electrically connected to the movable piece, wherein
the movable piece is provided, in a contact portion contacting with the second terminal piece, with a protrusion projecting toward the thermally-actuated element,
the movable piece is welded to the second terminal piece in the contact portion, and
a welded portion between the movable piece and the second terminal piece overlaps with the protrusion in a longitudinal direction of the movable piece.

### Claim 2 (depends on 1)

The breaker as set forth in claim 1, wherein the movable piece is disposed on a thermally-actuated element side of the second terminal piece.

### Claim 3 (depends on 1)

The breaker as set forth in claim 1, which comprises a first case in which a part of the first terminal piece is embedded and in which the thermally-actuated element is accommodated, and a second case in which a part of the second terminal piece is embedded and in which the movable piece is accommodated,
wherein the first case and the second case are fixed.

### Claim 4 (depends on 1)

The breaker as set forth in claim 1, wherein a center of the welded portion is displaced from a center of the protrusion toward the movable contact.

### Claim 5 (depends on 1)

The breaker as set forth in claim 1, wherein the movable piece has a bent portion bent so that the movable contact approaches the fixed contact.

### Claim 6 (depends on 1)

The breaker as set forth in claim 1, wherein an edge of the thermally-actuated element overlaps with the contact portion when viewed from a thickness direction of the movable piece.

### Claim 7 (depends on 1)

A safety circuit for an electric device, comprising the breaker according to claim 1.

### Claim 8 (depends on 1)

A secondary battery pack comprising the breaker as set forth in claim 1.