The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 1981
Filed:
May. 11, 1979
Dennis D Smith, Bartlett, IL (US);
Illinois Tool Works Inc., Chicago, IL (US);
Abstract
A thermal cut-off device is disclosed in which a first axial lead extends through an insulating member at one end of the device and a second axial lead contacts and extends through a conductive cylindrical housing at the other end of the device. A domed electrical contact cup is used in one embodiment to make electrical connection between the insulated lead and the outer metallic housing, and this electrical connection is maintained by a coiled helical spring. One end of the coiled spring is larger in diameter than the other end. The large diameter end is in engagement with the end of the conductive housing through which the second axial lead projects, while the smaller end of the conductive spring is in engagement with the insulated first axial lead, either directly or through the domed contact cup. The spring is held in a prestressed condition by a solid thermally fusible or meltable pellet which surrounds the spring, and which holds it in its stressed condition until the predetermined melting, or fusible, temperature of the pellet is reached at which time the stress is relieved in the spring and it contracts away from the insulated first axial lead, so as to break electrical connection between the leads of the device.