Abstract: An injection moulding system (10; 110; 210) of plastic material, comprising: a press (11; 111; 211) having a first (11a) and a second (11b) pressure plate, suitable for closing between them a mould (13; 113; 213), by applying on it a closing force (F), and a distribution and injection assembly (12; 112; 212), suitable for distributing and injecting a fluid plastic material (MP) into the mould (13; 113; 213) and in turn comprising an intermediate hot distribution plate (23; 123), interposed between a bottom plate (21) and a nozzle-bearing plate (22), provided for cooperating into contact and in relationship of sliding, along a respective sliding and contact surface (23a), with the end (17a) of one or more injection nozzles (17; 117), fixed on the nozzle-bearing plate (22), in order to distribute the fluid plastic material (MP) to be injected into the mould (13), wherein the distribution and injection assembly (12; 112; 212) is arranged adjacently to and along a side (13c: 113c; 213c), of the mould (13; 113; 21

Abstract: A nozzle has a tubular metal core which forms a central injection duct, and a cylindrical, outer, lateral surface. A heater/diffuser device includes a metal heat diffuser of tubular cylindrical shape with an open annular cross-section, mounted around the cylindrical surface of the core. The diffuser has: a cylindrical internal surface fitting the cylindrical surface of the nozzle core, two facing longitudinal free edges which are spaced apart circumferentially, are free of one another, and define between them a longitudinal space extending along a generator line of the cylindrical surface of the diffuser, and a recessed, channel-like seat formed in a surface of the diffuser element. A resistor is housed in the channel-like seat.

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: 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: A nozzle has a tubular metal core which forms a central injection duct, and a cylindrical, outer, lateral surface. A heater/diffuser device includes a metal heat diffuser of tubular cylindrical shape with an open annular cross-section, mounted around the cylindrical surface of the core. The diffuser has: a cylindrical internal surface fitting the cylindrical surface of the nozzle core, two facing longitudinal free edges which are spaced apart circumferentially, are free of one another, and define between them a longitudinal space extending along a generator line of the cylindrical surface of the diffuser, and a recessed, channel-like seat formed in a surface of the diffuser element. A resistor is housed in the channel-like seat.

Abstract: A combined heater and heat diffuser for fitting to an injection nozzle (10) for moulding plastics materials, where the nozzle comprises a tubular metal core (12) with an injection duct (14) and a cylindrical lateral surface (13). The heater and heat diffuser includes a resistor (40) housed in a channel-shaped seat (32) formed in a cylindrical internal surface (30d) of a heat diffuser (30) made of a metal material of a tubular shape for fitting around the core (12) of the nozzle.

Abstract: A combined heater and heat diffuser for fitting to an injection nozzle (10) for moulding plastics materials, where the nozzle comprises a tubular metal core (12) with an injection duct (14) and a cylindrical lateral surface (13). The heater and heat diffuser includes a resistor (40) housed in a channel-shaped seat (32) formed in a cylindrical internal surface (30d) of a heat diffuser (30) made of a metal material of a tubular shape for fitting around the core (12) of the nozzle.

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.

Abstract: A press for molding plastic materials wherein a stationary head and a movable head, arranged for receiving the two parts of a mold, are mounted on a base in which is installed a horizontal longitudinal member having pivoted at its ends vertical rocker levers. The upper ends of the rocker levers are connected to the stationary head and to the movable head respectively, and the lower ends thereof are connected to the ends of a hydraulic piston-cylinder assembly, which, thereby, applies to the heads a clamping force adequate to join the parts of the mold during the molding operation, without loading the base of the machine.