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. 02, 1999
Filed:
May. 05, 1997
Scott B Sehlhorst, Fort Wayne, IN (US);
Stephen Schamberger, Kendallville, IN (US);
Other;
Abstract
A user adjustable switching controller for duty cycle regulating flow of current to an electrical load such as a resistance heater, particularly for cooking appliances. A load current switch, when closed by a user operated cam also energizes a heat motor which includes a resistive strip attached to one active leg of a U-shaped bi-metal member. In one embodiment the integrally formed load current switch snap spring is securely attached to the heated leg of a U-shaped bi-metal and the moveable contact arm pivoted on the base. The other leg of the U-shaped bi-metal is anchored to a base including one of the load-connecting stationary terminals; and, the anchored leg serves to provide ambient temperature compensation. In another embodiment, the integrally formed blade spring of the moveable contact member is pivoted on the active leg of the U-shaped bi-metal and the moveable contact arm welded to the base. User rotation of the cam deflects a bias spring which acts on the portion of the bi-metal attached to the load switch snap spring to effect closing of the load current switch and energization of the heat motor. Heating of the bi-metal causes warpage which overcomes the bias spring to open the load switch and shut off the heat motor. Cooling of the bi-metal allows the load current switch to re-close repeating the cycle. User adjustment of the cam varies the bias on the snap spring and thus the re-open point of the switch with respect to the cycle, thereby varying the ratio of 'on' to 'off' time of the load current. The heat motor sub-assembly including the base with the load connecting terminal, the U-shaped bi-metal, the heater and the moveable contact arm and heater connecting chip is pre-fabricated and installed in the controller housing as a unit.