Temperature controlled cartridge heater
AssigneeFast Heat Element Manufacturing Co., Inc.
InventorFrank Lodi
Life of this patent
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Abstract
A temperature controlled electric heater for severing a web of vinyl film, which includes a metallic sheath having internal heater elements arranged in a ceramic core and has a thermistor nested in the core and in surface contact with the sheath for sensing the temperature of the heater, the sheath being adapted to heat sever the vinyl film web on contact therewith.
Claims9
An electric heater assembly for severing a web of plastic film at a given temperature, comprising a metallic sheath having an outside roughened surface and adaptable to contact said plastic web, dielectric core means within and substantially coextensive with said sheath, a longitudinal passage within said core means, a heating element extending through and secured in said passage, a thermal resistance body arranged between said sheath and core means but insulated from said heating element and in surface contact with said sheath for sensing the temperature of said sheath, a circuit connecting said heating element and said thermal resistance body with a source of electric current, and means in said circuit responsive to the temperature sensed by said thermal resistance body for controlling the flow of current to the heating element to maintain said sheath at said given temperature.
An electric heater assembly for severing a web of plastic film at a given temperature, comprising a metallic sheath adaptable to contact said plastic web, a dielectric core means in said sheath substantially coextensive therewith, at least one longitudinal passage within said sheath, a heating element extending through said passage and secured therein by said core means, a thermal resistance body within said sheath and arranged between said sheath and core means and substantially in surface contact with said sheath, a dielectric thermal insulation pad arranged between said thermal resistance body and said core means, a circuit connecting said heating means and said thermal resistance body with a source of electric current, and means in said circuit for controlling the flow of current to the heating element to maintain said sheath at said given temperature.
Dependencies are inferred from the claim text.