Patent ID: 9378910
Filing Date: 2016-06-28
CPC Classification: H01H

Claim Text:
1. A thermal cut-off device, comprising: a case extending along a longitudinal axis from a first end to a second end; a first electrically conductive member disposed at the first end of the case and extending from the case in a direction along the longitudinal axis; a thermally responsive member comprising a non-electrically conductive material that transitions from a solid physical state to a non-solid physical state at or above a threshold temperature; a second electrically conductive member disposed at the second end of the case, extending from the case in a direction along the longitudinal axis, and comprising a contact surface at a distal end thereof; an electrically conductive, moveable contact disposed between the thermally responsive member and the second electrically conductive member; a first biasing member disposed between the thermally responsive member and the moveable contact, the first biasing member biasing the moveable contact in a direction along the longitudinal axis toward the second electrically conductive member; and a second biasing member disposed between the moveable contact and the second end of the case, the second biasing member directly engaging the moveable contact and biasing the moveable contact in a direction along the longitudinal axis away from the second electrically conductive member; wherein the distal end of the second electrically conductive member comprises a concave portion and the contact surface comprises a generally flat, annular portion that encircles a periphery of the concave portion; and wherein when the thermally responsive member is below the threshold temperature and the thermal cut-off device is operable to conduct electrical current, the annular portion of the contact surface directly engages the moveable contact; and wherein when the thermally responsive member is above the threshold temperature and the thermal cut-off device is operable to interrupt electrical current, the annular portion of the contact surface is separated from the moveable contact.