Distributor and nozzle assembly for injection-molding machines

Claim 1

An injection-molding machine comprising an injection member adapted to displace a stream of thermoplastic synthetic-resin material at an elevated pressure; a mold member having at least one mold cavity and a plurality of inlet orifices in spaced-apart relationship, each communicating with a mold cavity; and a distributor member interposed between said injection member and said mold member for distributing said synthetic-resin from said injection member to said orifice, at least one of said members being shiftable relative to another of said members for urging said members together for distribution of said material, said distributor member comprising a respective nozzle assembly registerable with and adapted to communicate with each of said orifices, said distributor member having respective generally annular surfaces surrounding each of said orifices, and means for selectively displacing said surfaces for applying same against said mold member for individual sealing of said nozzle assemblies with said orifices. said mold member comprising a mold-bottoming plate formed with said orifices and juxtaposed with said distribution member, said mold-bottoming plate being provided with respective recesses opening in the direction of said distributing member and communicating with the respective orifices, said distributing member comprising a body provided with a plurality of arms together formed with one of said nozzle assemblies and a central passage communicating with said injection member and respective passages traversing said arms from said central passages to the respective assemblies, each of said nozzle assemblies comprising an injection nozzle head receivable with limited clearance in the respective recess and provided with an injection orifice, and a valve needle received in the respective nozzle head for selectively blocking the injection orifice thereof, each of said surfaces surrounding the respective nozzle head and bearing annularly upon said moldbottoming plate around the respective clearance, said body being provided at each arm with a respective hydraulically displaceable piston operatively connected to the respective needle for controlling the displacement thereof.