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:
Jul. 28, 1981
Filed:
Dec. 26, 1979
John K McVey, Bensenville, IL (US);
Illinois Tool Works Inc., Chicago, IL (US);
Abstract
The thermal switch of the present invention relates to thermal switches in which an organic pellet melts at a predetermined temperature which thereby allows the switch to change from a closed to an open state. More particularly, the switch is of the axial lead type wherein one of the leads is connected to the outside of a metallic housing for the device, and the other lead passes through an insulator into the interior of the housing. A thermally-sensitive pellet is positioned in the bottom of the metallic housing and a contact member is positioned in the gap between the pellet and the head of the insulated lead. A coiled spring encircles the insulated lead and forces the contact member toward the temperature-sensing pellet. The electrically conductive contact is formed with a bottom which either engages the pellet, or a wafer which is in contact with the pellet, and a top which is partially open and has a pair of inwardly bent ends that contact the head of the insulated lead at an angle. The contact is deformed due to the applied forces so as to engage the metallic housing of the switch. When the pellet melts, the spring forces the contact member away from the head of the insulated lead and the deformed condition of the contact is relaxed so that it is no longer in electrical contact with the metallic outer housing and thus the other lead of the switch.