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US 4,120,086 AGranted
Method of making electrically heated nozzle
AssigneeFast Heat Element Manufacturing Co., Inc.
InventorWalter R. Crandell
Life of this patent
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AssigneeFast Heat Element Manufacturing Co., Inc.
InventorWalter R. Crandell
Estimating the term…
An electrically heated nozzle device for plastic molding or die casting equipment having a novel casing with an integral heater core, and means to seal the casing for retaining the heater core in place and to electrically insulate the electrical heating element from the casing and prevent loss of thermal transmitting packing contained in the casing, which is structured to receive the heater core in the area close to its passage for carrying molten material to be molded or cast in a forming cavity, and which may be shaped. The casing may also include a probe for a thermocouple or a thermocouple well for sensing temperature; and the method includes the steps of arranging an unsheathed electric heating element in a bore formed in the nozzle casing in proximity to its molding material orifice, filling the bore with heat transmitting electrical insulation embedding an electric heating element, compacting the insulation about the heating element and in the bore to eliminate air voids, and sealing the bore. The method may also include the steps of assembling in the nozzle casing a body of relatively flexible green ceramic particles impregnated in heat dissipatable material and embedding a resistance wire heating element in the body, heating the assembly to bake out the heat dissipatable material and sinter the ceramic particles together, and compacting the assembly to eliminate air voids therein and between the casing and said assembly. Also disclosed herein in a heater body embodying modified features of the invention.
The method of making an integral heated torpedo for a molding nozzle which comprises winding a wire resistor upon a core having an opening therein extending the length thereof, extending a lead wire through said opening, connecting the end of said wire resistor to said lead wire, placing a ceramic spacer at each end of said core, inserting the core and spacers unsheathed into the open bore of a casing comprising a torpedo body closed at one end, filling the bore with heat transfer electrical insulation material to fill all voids in said bore between said core and spacers and said casing, placing an insulated washer in the open end of the bore, swaging the casing to reduce the diameter thereof and to pack the insulation material tightly around the core and in all gaps in the bore, and shaping the closed end of the casing.
In a method for making an electrically heated nozzle having a passage for injection of molten material into a forming cavity, said method comprising the steps of forming a bore in the nozzle body in proximity to the material injection passage, filling the bore with an unsheathed assembly of a winding of electric heater resistance wire embedded in heat transfer electrical insulation material without air gaps between said wire and said material, compressing the filled nozzle body to substantially eliminate all air voids in the assembly and between said assembly and said bore and to pack the insulation densely within said bore, connecting lead wires to the ends of said winding, and sealing said assembly in said bore.
Dependencies are inferred from the claim text.