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US 4,358,668 AGranted
Heater with reinforcing strate
AssigneeJames P. McMullan
InventorsJames P. McMullan, Albert Stevens
Life of this patent
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AssigneeJames P. McMullan
InventorsJames P. McMullan, Albert Stevens
Estimating the term…
A flat, normally horizontal electric resistance blanket heater comprising a thin, fragile elongate resistance element on one surface of and carried by a thin, flexible sheet of dielectric material, a thin, flat resilient and flexible reinforcing strate of dimensionally stable material retained adjacent the other surface of the film to permit flexure of the heater and without dimensional distortion of the film and element and a flexible envelope encapsulating the sheet element and strate. The heater also includes temperature responsive switching means responsive to the temperature of heated portions of the heater and in temperature insulated relationship from a portion of the heater where the element connects with power supply lines and which creates a portion in the heater of increased mass and heat storing capacity.
A flat, normally horizontal, flexible blanket type heater structure comprising a thin, horizontal reinforcing strate of flexible and resilient dimensionally stable material having flat top and bottom surfaces and outside edges, a thin, flat carrier sheet of flexible dielectric material of limited dimensional stability having flat top and bottom surfaces and outside edges positioned with its bottom surface in flat opposing engagement with the top surface of the strate, an elongate, metallic electric resistance element on and arranged to extend throughout the major portion of the top surface of the carrier sheet with each portion thereof in spaced relationship from other portions thereof, said element has end portions extending to a portion of the carrier sheet spaced from the element and joined with electric terminals carried by the carrier sheet, a flat, horizontal envelope of flexible dielectric sheet material of limited dimensional stability with top and bottom layers and outside edges engaged with and about the strate, carrier sheet and element and normally holding the strate, carrier sheet and element and normally holding the strate and carrier sheet in surface to surface engagement and against movement relative to each other and having an access opening through which the terminals extend.
A multi-laminate heater structure with a heat conducting and distributing reinforcing strate, an elongate, electric resistance element electrically insulated from and extending about a surface of a major portion of the strate, said element has end portions joined with terminals in the heater structure adjacent a minor portion of the strate adjacent said major portion thereof and spaced from the element, an elongate power cable extending to the heater structure with one end portion terminating adjacent said minor portion of the strate and having conductors connected with the terminals, a body of heat absorbing dielectric material about said end portion of the cable, the terminals and the conductors and in heat transfer relationship with aid minor portion of the strate, at least one temperature responsive switching device in heat conducting relationship with the heater structure related to the major portion and adjacent a side of the minor portion of the strate and series connected in the circuit established by the element and conductors and operating to open the circuit when the temperature of the portion of the heater structure with which it is related reaches a predetermined elevated temperature, said strate has a heat gap opening in it between its major and minor portions stopping conduction of heat by the strate between the portions of the heater structure at opposite sides of the heat gap opening.
Dependencies are inferred from the claim text.