Abstract: Closure assembly (10), for an injection unit (11) of plastic material (MP), comprising: a closing rod (16); a driving piston (15) adapted to drive an axial movement (f1) of the closing rod (16) between an open position (P1), in which the closing rod (16) opens an injection hole (13?) of a mold (13), and a closed position (P2), in which the closing rod (16) closes the injection hole (13?); an adjustment element or nut (20, 21), provided of a fine-pitch threading (21a), that is adapted to be screwed or unscrewed in one sense or the other (f2) in a corresponding threaded portion (22b) of an internal seat (22), formed in the driving piston (15), in order to regulate axially, in a micrometric way, the closing rod (16) in the closed position (P2); and an elastic washer (30, 31) that is provided for cooperating with a plurality of projections and notches (23a, 23b), formed in such internal seat (22, 22a), in order to fix the adjustment element (21) with respect to the body (15a) of the driving piston (15), once the

Abstract: A closure assembly, of the type with a multi-rod drive, for the injection moulding of plastic material is described. The closure assembly has a plurality of closing rods and a driving plate, wherein the driving plate is adapted to move between an open position and a closed position. The closure assembly also has disconnecting and fixing means associated with each closing rod for disconnecting it from the driving plate, independently from the other closing rods, and to firmly fix it, once disconnected, on a side of the mould.

Abstract: An injection molding system of plastic material, includes a press having first and a second pressure plates, suitable for closing between them a mold, by applying a closing force, and a distribution and injection assembly suitable for distributing and injecting a fluid plastic material into the mold and in turn comprising an intermediate hot distribution plate interposed between a bottom plate and a nozzle-bearing plate, provided for cooperating into contact and in sliding relationship, along a respective sliding and contact surface with the end of one or more injection nozzles fixed on the nozzle-bearing plate, in order to distribute the fluid plastic material to be injected into the mold, wherein the distribution and injection assembly is arranged adjacent to and along a side of the mold, not associated with the first and the second pressure plates so as not to be subject to the closing force of the mold.

Abstract: A cylindrical switch has one or more passages which open onto a lateral cylindrical surface of the switch. The switch is capable of being tightly received in a cylindrical hole in a hot plate and of being selectively orientated so that the passages are angularly in line with or offset from two or more channels in the hot plate which open onto the hole in order to selectively permit, interrupt or divert the flow of molten plastics material between the aforesaid channels. The switch incorporates a circuit for a cooling fluid.

Abstract: The actuating unit comprises a piston element (21) slidable in a cylinder element (20) and connectable to a closure rod (16) slidable in an injection duct (14) between an extended position in which it blocks an injection hole (15) and an injection position in which it is retracted into the injection duct. The piston element (21) has an engaged seat (46, 47) which can house a head end portion (16a) of the rod (16). The engagement seat is shaped so as to allow the piston element (21) to be translated transversely relative to the axial direction of movement of the rod (16) in order to release the piston element (21) from the rod.