Abstract: The invention relates to a non-return valve, which is situated at the end of a plasticizing and injection screw to control the flow of plastic melt from the region of the screw channels of the plasticizing and injection screw to the region of the space in front of the screw of a preplasticizing cylinder, where the plasticizing and injection screw is situated, the non-return valve having a basic body, which is rigidly connected to the plasticizing and injection screw, and an outside part, which can move translationally and preferably also rotationally relative to the basic body, so as to allow the flow of plastic melt in a first position and block the flow of plastic melt in a second position.

Abstract: The invention relates to a non-return valve, which is situated at the end of a plasticizing and injection screw to control the flow of plastic melt from the region of the screw channels of the plasticizing and injection screw to the region of the space in front of the screw of a preplasticizing cylinder, where the plasticizing and injection screw is situated, the non-return valve having a basic body, which is rigidly connected to the plasticizing and injection screw, and an outside part, which can move translationally and preferably also rotationally relative to the basic body, so as to allow the flow of plastic melt in a first position and block the flow of plastic melt in a second position.

Abstract: A hydraulic operating system for plastic processing machines, especially for injection molding machines, comprises a hydraulic pump (1), which is driven by an electric motor (2), at least one hydraulic drive (3, 4, 5), a hydraulic line network (6), which connects the hydraulic pump (1) and the hydraulic drives (3, 4, 5), and a machine control (7), in which the hydraulic pump (1) is designed a continuous or constant transport pump and the electric motor (2) is operated at a variable rpm, being appropriately influenced by the machine control (7).

Abstract: It is proposed that a pressure control device and/or pressure regulating device (8) be used for a fluid medium, in particular air or gas, preferably nitrogen, which is to be supplied to an injection mold in addition to the molten plastic, this pressure control device and/or pressure regulating device (8) being provided as a stationary, but preferably as a mobile unit between a pressure generator/pressure accumulator (7) and an injection system associated with the injection mold (3), e.g., in a nozzle head or add-on building block.

Abstract: A hydraulic operational system for an injection molding machine, including a hydraulic line network, a plurality of hydraulic drives for driving different components of the injection molding machine, a plurality of directional control valves, for connecting the hydraulic drives with the network, a constant delivery pump for supplying the hydraulic line network with hydraulic fluid, and a steplessly controlled electric motor or a multi-stage electric motor for driving the constant delivery pump, and a maximum driving speed of which is controlled so that it corresponds to the hydraulic pump operation at which the hydraulic pump provides at least one of a delivery volume and a hydraulic fluid pressure corresponding to the at east one of a maximum amount of the hydraulic fluid and a maximum pressure of the hydraulic fluid required for operating all of the plurality of hydraulic drives.

Abstract: A closing unit for injection mold machines is disclosed which generally includes two end plates, guide crosspieces connecting the end plates at a distance from one another, an intermediate plate which is parallel to the end plates and displaceable longitudinally relative to the guide crosspieces and moving cylinders which abut an end plate and act at the intermediate plate via their piston rods. The moving cylinders also displace the intermediate plate along the guide crosspiece in the closing and opening direction to vary its distance from the other end plate. The intermediate plate and the other end plate form a gripping plate for the two mold halves of a form tool which is brought into its closing position by the two gripping plates. Increased closing force may be applied to the form tool at a central die via a pressure cushion insertable between one end plate and the intermediate plate.

Abstract: A displacement and/or actuating force drive device for an injection molding machine, for example, for actuation of the push-type screw of a plasticizing extruder or the closing unit of an injection mold, comprises generally a hydraulic stroke drive, in tandem in rows or in series with a mechanical stroke spindle system driven by a brushless three-phase servomotor type electromotor. The motor is associated with a positioning regulation device dependent upon the closing and opening position of the injection mold. The hydraulic stroke drive can be actuated from a pressure regulation circuit by a servo valve. The circuit depends upon the closing force between the two mold halves of the injection mold.

Abstract: An apparatus for injection molding of plastics material in accordance with a gas or liquid injection method. The apparatus includes a nozzle which can be applied to the injection molding die or the injection mold. This nozzle enables selectively the sole injection of plastics material melt, the simultaneous injection of plastics material melt and medium as well as the sole injection of medium into the mold cavity of the injection molding die or injection mold. The melt is supplied to the nozzle mouth by the extruder screw cylinder of the extruder around a nozzle torpedo, while the medium is introduced into the nozzle so as to be spaced from the nozzle mouth.

Abstract: An arrangement for securing a die to a die holder for use as a molding die in an injection molding machine permits the die to be oriented on the die holder in a number of different angularly rotated positions. Clamping bolts secured to the die extend perpendicularly of a contacting plane between the die and die holder and project into corresponding holes in the die holder. Slides are provided in passageways in the die holder with the passageways extending parallel to the contacting plane. The slides are displaceable in the passageways into securing and clamping engagement with the clamping bolts. The slides are wedge-shaped and inter-engage corresponding wedge-shaped recesses in the outer surface of the clamping bolts. The slides can be displaced by actuating members. Hydraulic piston cylinder units can be used as the actuating members for holding the slides in the clamped position during operation.

Abstract: A coupling device of the insertion or plug-in type for connecting lines which conduct flowing media, preferably pressurized fluids, to the mold halves of a molding tool in an injection molding machine. The coupling device includes a first coupling member, for example, a coupling nipple, mounted on an adapter plate of the injection molding machine and a second coupling member, for example, a coupling sleeve, mounted on a mold half of the molding tool. A locking device is used for fixing the two coupling members in an engaged position. The locking device is biased into its locking position by means of a spring and can be moved against the biasing force by means of an electromagnet from the locking position into a releasing position.

Abstract: There is disclosed an injection molding assembly comprised of a tool unit and two extruder units each including a drive unit spatially-disposed from one another and mounted for transverse movement with respect to the tool unit. In one embodiment of the present invention, if the extruder units are provided with hydraulic drive units, the extruder unit which is not coupled to the tool unit may be placed in fluid communication via a switching device with a low capacity hydraulic pump.

Abstract: A mold closing and locking device is disclosed, including a fixed mold carrier plate, a stationary end plate, a movable mold carrier plate displaceable between the fixed mold carrier plate and the stationary end plate on support shafts through the action of a piston-cylinder unit, an adjustable distance-determining member extending between the piston-cylinder unit and the movable mold carrier plate, a pressure plate carried on a swivel arm for movement into and out of engagement between said piston-cylinder unit and said distance determining member, with the swivel arm being attached to a pivot bearing mounted on one of the aforesaid support shafts, with the pressure plate having a limited displacement range against spring tension in a direction parallel to the movement of the movable mold carrier plate, and with the swivel arm being movable by means of a pressurized pivot drive supported on another of the support shafts.