Device for the electric heating and fluid cooling of an injection-molding machine nozzle

A heating and cooling jacket for synthetic resin distributor for an injection molding machine, comprising:

• a cylindrical circumferentially closed one-piece prefabricated outer metal sleeve;
• a cylindrical, circumferentially closed prefabricated intermediate metal sleeve coaxial with and disposed within said outer metal sleeve and radially spaced therefrom to define an outer annular compartment between said inner and outer metal sleeves;
• a cylindrical, circumferentially closed prefabricated inner metal sleeve coaxial with and disposed within said intermediate metal sleeve and radially spaced therefrom to define an inner annular compartment between said inner metal sleeve and said intermediate metal sleeve;
• means for closing said inner and outer annular compartments at opposite axial ends thereof;
• a cooling coil having a multiplicity of cooling-tube turns of flattened cross-section lying against said intermediate metal sleeve and against said inner metal sleeve within said inner annular compartment, at least some of said inner turns being separate from one another by interturn spaces;
• an electric heater having a plurality of helical turns in spaced apart relationship in said outer annular compartment and in contact with said intermediate metal sleeve;
• a first means of densely packed heat-conductive metal particles filling said outer annular compartment and spaces between the turns of said heater between said outer metal sleeve and a second mass of high conductivity densely-packed metal particles filling said inner annular compartment between said inner metal sleeve and said intermediate metal sleeve and the spaces between the cooling-tube turns of said cooling coil.