Patent ID: 8047836

Claim:
A nozzle valve gate apparatus for delivering and injecting hot plastics material into an injection mold for molding a plastics product or part, said nozzle valve gate apparatus comprising: a chamber forming body having first passage means for flow of said hot plastics material from a plastics inlet to at least one plastics outlet, said body forming an actuator chamber; a nozzle part connected to said body and having a longitudinal axis, said nozzle part extending in the longitudinal direction to a nozzle tip having an injection aperture for said hot plastics material to flow into said injection mold, said nozzle part forming second injection passage means operably connected to said at least one plastics outlet for conducting said hot plastics material to said injection aperture and forming a longitudinal guide passage comprising a machined bore; a valve pin extending through said guide passage and movable therein in the longitudinal direction between an open position at which said hot plastics material can flow through said injection aperture and a closed position which stops flow of the plastics material through the injection aperture; a piston connected to said valve pin, slidably mounted in said actuator chamber, and adapted to move said valve pin between said open and closed positions by way of fluid pressure in said actuator chamber during use of said valve gate apparatus; and an elastomeric wiper seal extending around and engaging said, valve pin adjacent said machined bore, said wiper seal being made of wear resistant material and being capable of withstanding operating temperatures for said valve gate apparatus of at least 200° C., wherein a micro gap between 1 and 10 microns is formed between said valve pin and said machined bore, and a zero gap is formed between said wiper seal and the valve pin.