Abstract: A plastic injection mold apparatus which includes a multiple tip torpedo heater in a fluid plastic flow passageway. The torpedo heater includes an elongated body having an exposed outer cylindrical surface with tips at opposite ends thereof over which the fluid plastic material may be directed at an elevated temperature. The body is formed with an internal bore at the location of each tip for receiving a respective heating element. The torpedo heater is supported within the fluid plastic flow passageway by means of an outer cylindrical collar portion and three circumferentially spaced radial supporting elements which are formed of a softer metallic material than the body of the torpedo heater, and hence, are susceptible to repeated thermally induced expansion and contraction without undesired cracking or failure which can result in leakage of the flow stream and heater failure.

Abstract: A plastic injection mold apparatus which includes a multiple tip torpedo heater in the fluid plastic flow passageway. The torpedo heater includes a pair of substantially identical tip members and a mounting collar which together define an exposed outer cylindrical surface of substantially uniform diameter with a tip at each end thereof over which the fluid plastic material may be directed at an elevated temperature. The tip members each are formed with an internal bore for receiving a respective electrical heating element, the leads of which exit the heater through the central mounting collar. The torpedo heater is retained in mounted position by means of a removable bushing, which permits relatively easy removal and replacement of the heater. The mounting collar and bushing each are formed so that an insulating air space is defined about their outer peripheries for enhancing the energy efficient operation of the molding operation.

Abstract: A unitary integral electrically heated nozzle device for plastic molding or die casting equipment which has a novel casing integral with a heater core, which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, the electrical insulation being compacted within the casing and around the heater core and the assembly being sealed and swaged into a unitary form, said device being structured to heat the area of a gate or passage for delivery of molten material into a forming cavity. The nozzle device may be shaped, and the nozzle systems include such nozzle devices in the gate channels for delivering molten material to the forming cavity.

Abstract: A plastic injection molding system having a plurality of multiple tip torpedo heaters which each have a casing with a pair of opposed tips disposed in respective sprue passageways in a mold. An unsheathed electrical heating element is disposed in an internal bore of the casing at each tip and heat transmitting material is compacted in the bore in surrounding relation to the heating element for electrically insulating each heating element from the casing and filling all air voids between the casing and heating element to effect direct heat transfer to the casing. Electrical leads couple the plurality of heating elements to a power source to permit independent temperature control of the individual heating elements and the exposed surfaces of the respective casing tips over which fluid plastic material is directed.

Abstract: A unitary integral electrically heated nozzle device for plastic molding or die casting equipment which has a novel casing integral with a heater core, which is insulated to prevent conduction of electricity and loss of thermal transmission to the casing, the electrical insulation being compacted within the casing and around the heater core and the assembly being sealed and swaged into a unitary form, the device being structured to heat the area of a gate or passage for delivery of molten material into a forming cavity. The nozzle device may be shaped, and the nozzle systems include such nozzle devices in the gate channels for delivering molten material to the forming cavity.

Abstract: 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.

Abstract: A temperature controlled electric heater for severing a web of vinyl film which includes a plastic coated metallic sheath having internal heater elements arranged in a ceramic core and a thermal resistance element nested in the core and in surface contact with the sheath for sensing the temperature of the heater; and means for securing the heater rigid and aligned with a web of vinyl film, said web being held under tension, and the heater being adapted to heat sever the film on contact with the web when the web is drawn over the heater.

Abstract: A torpedo heater device for plastic molding or diecasting equipment comprised of a novel casing having an integral heater core and means to seal the casing for retaining the heater core in place and preventing loss of thermal transmitting packing contained in the casing, and which is structured to receive the heater core in the area close to its tip, which is tapered. The casing may also include a probe for a thermocouple or a thermocouple well.

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.