Nozzle and apparatus for injection molding

An apparatus for controlling flow of melt through a mold arrangement comprising plural mold assemblies, the apparatus comprising at least one conduit for conveying melt from an injection unit to at least one mold assembly, the conduit comprising mating segments abutted with closure of the mold assemblies and separated with opening of the mold assemblies, at least one of the mating segments comprising a nozzle comprising:

• (i) a nozzle body having a nozzle passage therethrough joining a nozzle inlet and nozzle outlet;
• (ii) a valve pin movably supported within the nozzle passage and having a pin passage therethrough in communication with the nozzle passage and at least one contact arm transverse to and extending beyond the nozzle passage, sealing engagement of the valve pin and nozzle passage preventing melt bypassing the valve pin through the nozzle passage whereby melt is conducted through the pin passage between the nozzle inlet and the nozzle outlet;
• and (iii) a valve pin biasing means, the biasing means biasing the valve pin to a closed position for preventing passage of melt through the nozzle passage, and the contact arm effecting movement of the valve pin relative to the nozzle body to an open position when forces acting on the contact arm are sufficient to overcome the biasing means;
• the nozzles being mounted in the apparatus so that the valve pins are displaced to the open positions by forces applied to the contact arms as a result of closure of the mold assemblies whereby the open positions enable flow of melt through the nozzles.