Abstract: An expansion nozzle for conducting melt from a floating manifold to a mold assembly comprises a bushing having a bushing flange and spigot having a passage therethrough joining a nozzle inlet and an outlet, a head having a seating surface and a bore through the head slidably receiving the spigot so that the spigot is movable relative to the head over a range from abutting contact of opposing surfaces of the head and bushing flange to a limit of axial separation of the opposing surfaces, axial separation of opposing surfaces of the head and bushing flange being maintained throughout an operating temperature range. Springs maintain sealing contact of a seating surface of the head with a mating surface of the mold assembly. Advantageously, a locating ring provides a reaction surface for the springs and supports the head to resist moments arising from axial misalignment of the expansion nozzle and mold assembly.

Abstract: A nozzle for controlling flow of melt in a mold assembly comprises a valve pin guide interposed between a nozzle inlet and nozzle outlet, a valve pin movably supported thereby, and a contact arm engaging the valve pin and transverse to and passing through the valve pin guide. Biasing means acting on the contact arm hold the valve pin in a position preventing flow of melt. As the mold assembly closes, forces exerted on the contact arm overcome the biasing means and allow the valve pin to move to a position permitting flow of melt. Relief of pressure of retained melt is effected when force therefrom exerted on the valve pin exceeds an adjustable pre-load of the biasing means. The nozzle advantageously comprises an inlet bushing movably supported by the nozzle body enabling adjustment of the overall length of the nozzle to accommodate a range of spacing of elements of the mold assembly.

Abstract: An expansion nozzle for conducting melt from a floating manifold to a mold assembly comprises a bushing having a bushing flange and spigot having a passage therethrough joining a nozzle inlet and an outlet, a head having a seating surface and a bore through the head slidably receiving the spigot so that the spigot is movable relative to the head over a range from abutting contact of opposing surfaces of the head and bushing flange to a limit of axial separation of the opposing surfaces, axial separation of opposing surfaces of the head and bushing flange being maintained throughout an operating temperature range. Springs maintain sealing contact of a seating surface of the head with a mating surface of the mold assembly. Advantageously, a locating ring provides a reaction surface for the springs and supports the head to resist moments arising from axial misalignment of the expansion nozzle and mold assembly.

Abstract: A nozzle for controlling flow of melt in a mold assembly comprises a valve pin guide interposed between a nozzle inlet and nozzle outlet, a valve pin movably supported thereby, and a contact arm engaging the valve pin and transverse to and passing through the valve pin guide. Biasing means acting on the contact arm hold the valve pin in a position preventing flow of melt. As the mold assembly closes, forces exerted on the contact arm overcome the biasing means and allow the valve pin to move to a position permitting flow of melt. Relief of pressure of retained melt is effected when force therefrom exerted on the valve pin exceeds an adjustable pre-load of the biasing means. The nozzle advantageously comprises an inlet bushing movably supported by the nozzle body enabling adjustment of the overall length of the nozzle to accommodate a range of spacing of elements of the mold assembly.

Abstract: A pressurized-fluid-operated actuator has two piston surfaces for providing increased output force. The actuator includes a hollow piston that is divided into two inner chambers by a stationary inner dividing wall that is rigidly connected with a cylinder end wall. The piston has an outer diameter that is smaller than the inner diameter of the cylinder, and the piston carries three axially spaced sealing rings that define two axially-spaced annular chambers between the piston and the cylinder. Each of the annular chambers is in fluid communication with a respective port provided in the cylinder wall. Introduction of pressurized fluid into one port causes the fluid pressure to act on a single piston surface to retract the piston and rod, and introduction of pressurized fluid into the other port causes the fluid pressure to act on two axially-spaced piston surfaces to provide an increased output force without increasing the diameter of the cylinder and piston and without increasing the pressure of the fluid.

Abstract: In a thermal plastic molding device, a thermal insulator is provided between the nozzle assembly and the surrounding plates. Preferably, the insulator is a ceramic material, such as zirconia oxide, which is sprayed on in a thin coating, preferably in the range of 0.007-0.012 inches. Alternatively, other nonmetallic coatings can be used, or the insulator can be provided as a ring around the nozzle assembly instead of as a coating. A coating can be applied either to the plate or to the nozzle assembly. A protective coating, preferably a metal, is sprayed or plated over the ceramic insulator.