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. 14, 1989
Filed:
Jan. 25, 1988
Daniel S Query, Antioch, TN (US);
Linda A Zummer, Reims, FR;
Whirlpool Corporation, Benton Harbor, MI (US);
Abstract
A fiber optic door ajar sensor for a domestic appliance such as a refrigerator/freezer having refrigerator compartment and freezer compartment doors includes a light transmitter and a light receiver. In one embodiment, a U-shaped loop of fiber optic cable is positioned relative to the transmitter and the receiver so that changes in the amount of light transmitted from the transmitter via the fiber optic cable to the receiver enables the receiver to determine whether one of the doors is open or slightly ajar. Another embodiment of the door ajar sensor includes a fiber optic cable having one end adjacent to one of the doors and a distal or transmitting end adjacent to a light receiver. When the door is opened or left ajar, ambient light is transmitted via the fiber optic cable to the receiver. The receiver responds to a preselected amount of light received via the fiber optic cable by providing a door open indication. In another embodiment of the door ajar sensor, a light transmitter and a light receiver are respectively positioned adjacent to the refrigerator and freezer doors. A first L-shaped fiber optic cable is disposed in the refrigerator door relative to the transmitter and a second L-shaped fiber optic cable is disposed in the freezer door relative to the receiver and the first fiber optic cable. If either of the doors is opened, less than a predetermined amount of light is received by the receiver from the transmitter so that a door open signal is provided.