Anti-condensation system for refrigerator doors
First Claim
1. For use with a refrigerator door having an electrically heated door frame including a door frame heating element and an electrically heated window including a window heating element to prevent condensation and frost from forming, apparatus for providing variable levels of heating, comprising:
- switching means electrically connectable to the door frame electrical heating element and to the window electrical heating element for selectively altering the manner in which said door frame electrical heating element and said window electrical heating element are electrically interconnected from a series connection to a parallel connection, to alter the effective electrical resistance of the combination of said door frame and window electrical heating elements, whereby a plurality of levels of heating are selectively obtainable when the combination is connected across a voltage source of electrical current.
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Accused Products
Abstract
A system is described which permits the electrically heated door of a refrigerated display cabinet to be operated selectively at a plurality of power settings, providing respectively higher and lower levels of electrical heating. A switching means is used to alter the electrical interconnection of the door window heating elements with the door frame heating elements from a series connection to a parallel connection. In one embodiment, an automatic electrical controller actuates the switch in response to changes in the ambient humidity and temperature.
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Citations
9 Claims
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1. For use with a refrigerator door having an electrically heated door frame including a door frame heating element and an electrically heated window including a window heating element to prevent condensation and frost from forming, apparatus for providing variable levels of heating, comprising:
switching means electrically connectable to the door frame electrical heating element and to the window electrical heating element for selectively altering the manner in which said door frame electrical heating element and said window electrical heating element are electrically interconnected from a series connection to a parallel connection, to alter the effective electrical resistance of the combination of said door frame and window electrical heating elements, whereby a plurality of levels of heating are selectively obtainable when the combination is connected across a voltage source of electrical current. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. For use with a refrigerator door having a door frame and a window, the door frame having an electrical door frame heating element for warming it and the window having an electrical window heating element for warming it, the improvement comprising an electrical switch for selectively connecting the door frame heating element and the window heating element in either series or in parallel connection.
Specification