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. 22, 1977
Filed:
Jan. 19, 1976
Ronald L Holden, Mansfield, OH (US);
Therm-O-Disc Incorporated, Mansfield, OH (US);
Abstract
A hermetically sealed motor protector or the like is disclosed in which a switch chamber is defined by a cylindrical, cup shaped element and a header welded to one end thereof. A pair of insulated pins extend through the header substantially parallel to each other and on opposite sides of the center axis of the device. A switch including a stationary contact mounted on one pin and a movable contact assembly supported by the other pin is arranged so that the line of action of the movable contact is along a diametrical plane inclined with respect to the pins. Such structure facilitates the assembly of the device. The structure is arranged so that the pins supporting the bimetal snap element limits movement of the free end thereof in a direction away from the fixed contact to reduce the tendency for calibration drift and fatigue cracking of the snap element. In one embodiment, a shunt formed of flexible material is connected in parallel to the bimetal snap element to provide greater current carrying capacity. In another embodiment, a resistance heater is connected in series with the bimetal snap element to increase current sensitivity. The offset structure allows the use of a straight resistance heater, positioned closely adjacent to the center line of the snap element for good heat transfer. The heater mounting is arranged to accommodate thermal expansion and contraction without altering the calibration of the device.