Abstract: In the case of an injection-molding machine with mold-protecting device, every time the machine is started up a predetermined number N of injection-molding cycles are run at a greatly reduced machine speed in order to allow the mold-protecting device to be operated with increased sensitiveness during these cycles. If no trouble occurs during the said N cycles, the machine speed is increased to operating speed, either abruptly or continuously, and the mold-protecting device is either switched off or operated thereafter with adapted sensitivity.

Abstract: A mold clamping apparatus for injection molding machines includes a stationary plate 2 for supporting a stationary mold Cc; a moving plate 6 for supporting a moving mold Cm; a plurality of parallel tie bars 3a, 3b, 3c, and 3d of which end portions are secured to the stationary plate 2; a plurality of different cylinders 4a-4d . . . which accommodate piston sections 5a, 5b, 5c, and 5d set at the middle of each tie bar, and arranged movably along the tie bars and integrally with the movable plate; and a hydraulic circuit 7 capable of selective feeding of pressurized oil to the oil chambers of the cylinders. The piston sections of different cylinders are formed in different diameters and all portions of all tie bars are formed in the same diameter.

Abstract: An apparatus for injection molding plastics material has an injection unit for delivering a plasticized melt through a nozzle, a press unit for urging a mold together at a predetermined pressure, a mold mounted in the press unit and a programmable controller operably connected to the injection unit and the press unit for automatically controlling the operation of the apparatus for repetitively producing uniform articles. The mold has a stationary mold section and a moveable mold section. The press unit is adapted for reciprocating the moveable mold section between an open position and a closed position. The stationary mold section has a plurality of ports at pre-selected points. Each port has a controllable gate for selectively opening and closing the ports for passing melt to a mold cavity until the melt fully occupies the mold cavity while controlling and minimizing melt lines formed when a flow of melt from one of the ports meets with a flow of melt from another of the ports.

Abstract: A plastic molding device for plastic molding a semiconductor element includes upper mold and lower molds, each mold having a plurality of cavities, injection passages for injecting plastic into the cavities, and eject pins for ejecting plastic molded semiconductor elements from the cavities; a plastic injecting mechanism for injecting plastic into the cavities; and a mold driving mechanism for driving the upper or lower molds to join and separate them. The plastic molding device further includes a pin driver for projecting the eject pin after injection of the plastic into the cavities is completed while the upper and lower molds are together. Therefore, shrinkage deformation on a surface of the plastic molded product is prevented, whereby a plastic molded semiconductor device having a smooth surface is produced.

Abstract: A horizontal injection and compression molding apparatus has an injection device (3) and a compression molding device, wherein the compression molding device (2) includes: a stationary die plate (12) for holding a stationary die (11), a movable die plate (22) for holding a movable die (21), means (30) for rapidly extending and retracting the movable die plate (22), relative to the stationary die plate (12), means (40) for locking the movable die plate (22) to tie bars (51) at a position where the movable die plate (22) approaches the stationary die plate (12), and means (50) for fastening the dies after the movable die plate (22) is locked to the tie bars (51); and wherein the injection device (3) for feeding a molten plastic material into a mold cavity (90) between the stationary die (11) and the movable die (21) is characterized in that it initiates feeding of the molten plastic material into the mold cavity ( 90) when the stationary die (11) and the movable die (21) are parted from each other by a predeter

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 mold clamping device in an injection molding machine comprises a first platen for retaining a first mold therein and a second platen for retaining a second mold therein; a platen feeding mechanism for moving said first and second platens relative to each other on said table; electromagnetic coils arranged on the opposite surfaces of the first and second platens; and a control device for controlling the amount of the current supplied to the electromagnetic coils. The mold clamping operation is carried out using the magnetic attracting force generated by the electromagnetic coils.

Abstract: A molding system has a base, a fixed mold plate secured to the base, a fixed mold half carried on the fixed mold plate, a movable mold plate displaceable on the base longitudinally forward away from the fixed mold half and backward toward the fixed mold half, and a movable mold half carried on the movable plate and fittable with the fixed mold half. A mold-closing apparatus has a pair of main cylinders fixed to the fixed mold half and respective main pistons subdividing the main cylinders into respective front and rear main compartments and each having a piston rod secured to the movable mold plate and formed with a longitudinally extending chamber. A small-diameter fast-closing piston and cylinder are formed in one of the piston rods, and the other piston rod is provided internally with a force-amplifying piston unit. Two flow-control valves and check valves control the system.

Abstract: A molding press (10) for simultaneously operating a pair of molds, each having a pair of mold sections (M1, M2; M3, M4), including a base (13) for mounting two horizontally displaced mold sections (M1, M3), each constituting one section of one of the pair of molds, a first bolster (11) for mounting a mold section (M2) in alignment for mating engagement with one mold section (M1) on the base, a second bolster (12) for mounting a mold section (M4) in alignment for mating engagement with the other mold section (M3) on the base, rod assemblies (30) for interconnecting the first bolster and the second bolster in fixed space relation, for guiding relative movement between the base and the bolsters during opening and closing of the pair of molds, and for mounting pistons (44, 160) operatively interrelated with cylinder assemblies (40,140) on the base, and an auxiliary cylinder assembly (70) for effecting relative movement between the base and the bolsters for opening of one of the pair of molds while closing the oth

Abstract: A clamping apparatus of molding machine including a base; a fixed board disposed on the base; a movable board movable relative to the fixed board; a plurality of mold clamping cylinders disposed in predetermined positions of the fixed board, the mold clamping cylinders each having a mold clamping piston with a tie bar reception hole and a tie bar connection device disposed on the mold clamping piston; a plurality of tie bars with a thread at their one end, the tie bars being disposed in correspondence with the mold clamping cylinders on the movable board; a plurality of mold opening/closing cylinders for moving the movable board; and an axially movable sleeve associated with each clamping cylinder for adjusting an axial position of an associated piston to adjust an engagement position of the tie bar connection device, the sleeve being disposed in an opening in the fixed board and forming an extension of the tie bar reception hole, with one end of the sleeve abutting against a reception wall provided in each p

Abstract: A mold clamp for an injection molding machine with a stationary mold clamping plate and a movable mold clamping plate displaceable on a sliding carriage, which mold clamping plates are arranged on a machine frame and support mold-halves of a mold for processing plastic material, on the sliding carriage side guide rollers are provided which are adjustable with eccentric bolts and are supported on the machine frame, an air clearance is provided between the movable mold clamping plate and the sliding carriage, which are connected with each other for relative movement therebetween by connecting elements and a vertical trunnion transversely displaceable to the machine longitudinal axis, and are secured together with fastening screws.

Abstract: A mold closing apparatus and process for use with an injection molding machine are described. The mold is opened and closed by hydraulic pressure. The disclosed apparatus and method relate to the use of an immobile differential piston within a displaceable, double-action differential piston which moves within an immobile piston cylinder. This arrangement permits the use of smaller diameters to produce the necessary closing force. The immobile differential piston contains the necessary hydraulic passage for routing hydraulic fluid to the appropriate surfaces for exerting opening and closing forces. The use of a plurality of displaceable, single-acting pistons in parallel with the differential piston further reduces the diameters needed for exerting the claim force. Locating these single-acting pistons within the support column cylinders makes for an ever more compact apparatus.

Abstract: A machine including a system for moving one member into engagement with another and to apply a high clamping force thereto. The system includes an electrically operated pump and an associated cylinder assembly. The cylinder assembly includes a housing having first and second chambers, each having actuating fluid therein. A piston is located within the housing and is coupled to one member. A ballscrew and associated nut are located within the housing coupled to the piston and arranged to move the piston in either of two opposite directions under power from an externally located electrical servomotor. When the piston is moved in one direction it carries the associated member into engagement with the other member and also causes actuating fluid to flow from the second chamber into the first chamber. The pump is arranged to provide additional actuating fluid to the first chamber for applying a clamping force directly to the piston, and not to the ball screw and nut.

Abstract: A mold clamping apparatus for use in molding machines such as injection molding machines, diecasting machines and press molding machines. The mold clamping apparatus includes a base; a fixed panel and a movable panel disposed on the base and respectively supporting mold halves; a plurality of tie bars each having a screw shaft at one end thereof which passes through the movable panel; a plurality of clamping cylinders disposed on the fixed panel for clamping an other opposite end of the tie bars when the mold apparatus is in a closed position; a mechanism for moving the movable panel toward and away from the fixed panel; an adjusting mechanism, disposed on the movable panel, for simultaneously fixedly adjusting the axial position of the plurality of tie screws with respect to the movable panel such that the distance between the movable panel and the fixed panel when the mold apparatus is in the closed position can correspondingly be adjusted so as to accommodate molds of varying sizes.

Abstract: A mold opening controller for injection molding machines, having a control unit for controlling the hydraulic circuit. The control unit having a setter for setting acceleration/deceleration functions of a movable portion such as the movable mold; a data input for the setter; an operational unit for calculating the acceleration/deceleration of portions of the movable mold and the acceleration/deceleration speeds at each moving position at the time of the acceleration/deceleration on the bases of data from the setter and the data input; a position sensor for detecting the moving position of the movable mold; and a control for controlling the hydraulic circuit so that acceleration/deceleration positions of the movable mold and its moving speed at each position correspond to the output values of the operational unit through the position sensor.

Abstract: A mold closing apparatus and process for use with an injection molding machine are described. The mold is opened and closed by hydraulic pressure. The disclosed apparatus and method relate to the use of an immobile differential piston within a displaceable, double-acting differential piston which moves within an immobile piston cylinder. This arrangement permits the use of smaller diameters to produce the necessary closing force. The immobile differential piston comprises the necessary hydraulic passages for routing hydraulic fluid to the appropriate surfaces for exerting opening and closing forces.The use of a plurality of displaceable, single-acting pistons in parallel with the differential piston further reduces the diameters needed for exerting the closing force. Locating these single-acting pistons within the support column cylinders makes for an even more compact apparatus.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is connected with one end of the toggle and is carried on a crosshead guide, and a ball screw is rotatably secured to the movable crosshead to extend in the direction opposite from the molds and through a stationary platen. A ball nut rotatably carried by the stationary platen is in engagement with the ball screw and is drivingly connected with a first motor to axially move the ball screw to provide between the molds a clamping force sufficient to resist separation of the molds during high pressure injection of molding material. A second motor is drivingly coupled with the ball screw and is movable therewith in an axial direction. The second motor is adapted to rotate the ball screw for rapid traverse movement of the movable crosshead to rapidly bring the molds into and out of contact.

Abstract: A close clamp cycle for an injection molding machine in which a toggle locking motion is executed using a plurality of velocities to permit faster clamp operation while maintaining control of the clamp to bring it quietly to its final position without damage to the machine.

Abstract: An apparatus and method for controlling an injection molding device having a mold cavity therein use of periodically generated signals representative of the mold cavity pressure and mold cavity volume. These signals are used to control the magnitude of the clamping force imposed on a movable mold member. During a first time period following closure of the gate, in response to the signals representative of cavity pressure and cavity volume, the clamping force imposed on the movable mold member is adjusted to maintain, in closed loop fashion, cavity pressure constant. During a second time period following closure of the gate, in response to the signal representative of the cavity volume, the clamping force imposed on the movable mold member is adjusted to maintain, in closed loop fashion, cavity volume constant.

Abstract: A friction clamp assembly for securing a mold of an injection molding machine in a closed position includes a column rigidly secured to a moving platen carrying a mold half and a gripper bush assembly for frictionally engaging and locking the column in a desired position. The clamp assembly further includes a clamp piston for clamping the moving platen in a mold closed position. The clamp assembly transmits a clamping force to portions of a moving platen other than end portions via the column so that platen parallelism is maintained during closing, injection and hold pressure portions of a molding cycle while platen bending is substantially avoided.

Abstract: The hydraulic system comprises a 4/4-way valve, which is adapted to control the velocity of the mold-closing operation and the fluid pressure during said mold-closing movement and to assume three consecutive control positions, in each of which fluid pressure is applied to a stationary piston of an advance-retract cylinder from a first cylinder chamber, which is nearer to the mold. One of said control positions is a differential control position, in which pressure fluid displaced from the second cylinder chamber of said advance-retract cylinder, which second chamber is remote from the mold, is supplied to a pressure conduit through a branch passage, which includes a non-return valve. The differential control position is preceded and succeeded by a transitional control position, in which the pressure fluid displaced from the second cylinder chamber is returned through the 4/4-way valve to a reservoir.

Abstract: The present invention relates to improved gripper bushing assemblies for use with injection molds, molding machines and other devices. In a first embodiment, the gripper bushing assemblies include an elongated flexible gripping sleeve positioned about a column member such as a tiebar. The sleeve is secured to a member such as a moving platen and is used to clamp the platen to the tiebar in a desired location. The gripper bushing assemblies further include one or more spacers intermediate the sleeve and the platen. The spacers engage the sleeve via a mechanical interlock. The sleeve and spacer(s) are capable of accommodating tiebar stretching which may occur as a result of clamping forces being applied to the mold via the platen. In a second embodiment, the spacer(s) are omitted and the gripping sleeve has a male thread which engages a female thread on the platen.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is connected with one end of the toggle and is carried on a crosshead guide, and a ball screw is rotatably secured to the movable crosshead to extend in the direction opposite from the molds and through a stationary platen. A ball nut rotatably carried by the stationary platen is in engagement with the ball screw and is drivingly connected with a first motor to axially move the ball screw to provide between the molds a clamping force sufficient to resist separation of the molds during high pressure injection of molding material. A second motor is drivingly coupled with the ball screw and is movable therewith in an axial direction. The second motor is adapted to rotate the ball screw for rapid traverse movement of the movable crosshead to rapidly bring the molds into and out of contact.

Abstract: A mold clamping pressure control method for injection compression molding through adjustment of the oil pressure in the mold clamping cylinder by the mold clamping cylinder control valve, wherein a resin temperature in the mold is detected by a resin temperature sensor, and detected values thereof are converted by a converter into electric signals, which are in turn compared with a series of the preset pressure changeover temperature setting values to output pressure changeover signals whenever the detected values correspond to the preset values. The pressure changeover signal selects any of a series of the preset pressure setting values to output the valve opening-shutting directing signals converted into a certain valve opening-shutting amount, thereby to control the opening-shutting amounts of the mold clamping pressure control valve.

Abstract: In an apparatus for the reaction injection molding of a shaped article from a polymerizable flowable resin-forming composition, once such composition has attained a predetermined increased level of viscosity as measured in situ within the mold cavity, an amount of pressure is applied to the polymerizing composition which is sufficient to maintain any entrapped gas(es) dissolved therein and/or to prevent the composition from pulling away from mold cavity surfaces.

Abstract: A clamping system for traversing and clamping molds in a molding machine, the clamping system including a toggle-type clamp arrangement defined by a plurality of pivotally connected links. A movable crosshead is carried on a crosshead guide, and a ball screw is non-rotationally secured to the movable crosshead to extend in the direction opposite from the face of a cooperating fixed mold portion. A pair of ball nuts are carried by the ball screw and each of the ball nuts is drivingly connected with a respective servomotor. One of the servomotors is adapted to provide rapid traverse movement for the movable crosshead, and the other servomotor is adapted to provide high torque for high clamping force to hold a pair of mold halves in tightly contacting relationship during the injection into a mold cavity defined by the mold halves of a flowable material under pressure.

Abstract: A clamping mechanism which includes a cylinder and a piston. The diameter of the piston is less than the internal diameter of a rear chamber of the cylinder such that fluid flows around the piston when the piston moves from an open position to an intermediate position. The diameter of the piston is equal to the internal diameter of a front chamber of the piston such that fluid cannot flow around the piston when the piston moves from the intermediate position to a closed position. To prevent cavitation within the cylinder, fluid is charged to the cylinder in accordance with the movement of the piston.

Abstract: A motor-operated, direct-pressure type mold clamping apparatus is capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in one with a moving platen, is rotated at high speed by a motor through gears and a clutch, so that a die is opened and closed at high speed. In a mold clamping operation, the ball screw is driven with a large rotatory force transmitted through a clutch and gears which, having a high reduction ratio, serve to increase the rotatory force of the motor. Thus, dies are clamped with a large clamping force.

Abstract: An injection bladder press characterized by a bladder mold including an upper mold part, a lower mold part and a mold core; a squeeze piston for squeezing the mold when closed; and an injection unit for injecting rubber molding material into the mold to mold a bladder therein. A flexible hose is connected at one end to the mold core for movement therewith and for delivery of fluid to the mold core, and at its other end to a self-retracting hose reel operative to pay out and retract the flexible hose during movement of the mold core. A top platen is mounted to a top bolster for movement away from the top bolster to facilitate access to the injection nozzle. The mold core actuator is located with a support column depending from a moving bolster. The support column is engaged by a pressure column for transfer of mold clamping force to the moving bolster from the squeeze piston in a bottom bolster.

Abstract: A motor-operated, direct-pressure type mold clamping mechanism capable of high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor. In the mold opening and closing operations, a ball screw, in engagement with a ball nut which is movable in unison with a moving platen, is rotated at high speed by a coarse-adjustment motor through gears, so that a die is opened and closed at high speed. In the mold clamping operation, the ball screw is driven by a fine-adjustment motor through a clutch and gears which, having a high reduction ratio, serve to enhance the rotatory force and provide greater clamping force.

Abstract: The method having a clamping cylinder which slidably fits a clamping ram whose front end is fixed on a movable board of an injection molding machine, etc.

Abstract: A method and apparatus controlling an injection molding machine having a compression process. The velocity is controlled using a closed loop single or multi-step programmed velocity control method or a closed loop multi-step programmed slope velocity control method. Pressure may be controlled using a multi-step programmed pressure control method in which a pressure signal is detected from a detector set in the mold die or set in the clamping cylinder. The method of the present invention improves the accuracy and density of articles molded.

Abstract: A vertical injection molding machine having an upper die (26) and a lower die (27) which are adapted to be brought together in the vertical direction by the force produced by a die closing device. The injection molding machine has an injection unit 1 disposed below the lower die (27) and is hinged through a hinge shaft (36) to a truck (35) movable along rails (37), such that the injection unit 1 is swingable vertically about the axis of the hinge shaft (36). The vertical swinging motion of the injection unit 1 is effected by cylinders (38) connected to an injection head (2) of the injection unit (1). A compression forming cylinder device (70) is provided on the lower end of each of a plurality of tie-bars which are connected between the upper die (26) and the lower die (27).

Abstract: In the present invention, an inner space of a clamping cylinder is divided into a front oil chamber and a rear oil chamber for liquid pressure by a piston section of a clamping ram, the front oil chamber and the rear oil chamber are connected with each other by a connecting path which is bored in the piston section of the clamping ram, and the front oil chamber is connected to a charge tank via a second open-close valve. In the clamping ram, an oil chamber for mold closure and an oil chamber for mold opening are formed by slidably fitting a high speed piston therein. A first open-close valve, which opens or closes the connecting path of the piston section of the clamping ram, is slidably fitted on the rear end section of the clamping ram. An oil chamber for valve opening, which is formed between the first open-close valve and the outer face of the clamping ram, is connected to the oil chamber for mold opening via a through-hole bored in the clamping ram.

Abstract: A mold clamping device is disclosed. The device includes a clamping ram, whose front end is connected to a moveable board of an injection molding machine, slidably fitted in a clamping cylinder, and a support cylinder provided in parallel to the clamping cylinder. A support piston is slidably positioned in the support cylinder, and the front end of the rod of the support piston is connected to the moveable board of the injection molding machine. A front chamber and a rear chamber of the clamping cylinder, divided by the piston section of the clamping ram, and a front chamber of the support cylinder are connected by an oil path. There is provided a valve for opening or closing the connection between the rear chamber of the clamping cylinder and the front chamber of the clamping cylinder and the front chamber of the support cylinder.

Abstract: A hydraulic actuator assembly for use in a mold clamping unit of an injection molding machine. The actuator assembly serves as a rapid-travel drive for mold opening and closing movements and as a source of elevated mold clamping pressure. Among the hydraulic elements contributing to the operation of the mold clamping unit are a power piston for effecting elevated mold clamping pressures and a drive piston for effecting rapid die closing movements. With the hydraulic actuator system of the present invention, it is possible to control the operation of the mold clamping unit based on two-sided hydraulic influencing of the power piston and the drive piston.

Abstract: A die closing and locking apparatus for use in a die press includes a two-part linkage and cylinder combination wherein one part includes a toggle mechanism and the other part includes an annular hydraulic cylinder. The toggle mechanism operates on the closing portion of the die so as to move it into position rapidly and with the minimum time required. The annular hydraulic cylinder acts upon the die in the closing portion so as to apply the required closing force on the die, via the toggle mechanism, prior to the casting or molding operation.

Abstract: A direct pressure type mold clamping apparatus for an injection-molding machine is capable of performing high speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large sized motor, the mold clamping apparatus being driven by two motors. A movable platen is driven by servomotor at high speed to a die touch position. An error register of a servo circuit is supplied with distributed pulses which correspond to a moving amount from the die touch position to a set mold clamping force producing position. The movable platen is then driven in a mold clamping direction with a greater driving force by an induction motor. Thereafter, pulse signals outputted by a position detector are supplied to the error register corresponding to movement of the movable platen to gradually reduce an error value of the error register. When the error register value is reduced to zero, arrival at the set mold clamping force producing position is determined.

Abstract: A direct-pressure type mold clamping apparatus of an injection-molding machine, capable of performing high-speed mold closing and opening operations and of producing a required mold clamping force, without the use of a large-sized motor, is driven by two motors. The mold clamping apparatus includes a ball screw (6) engaging a ball nut (7) which is movable in unison with a movable platen (1). The ball screw is coupled to a servomotor (10) through a transmission mechanism (8, 9, 11, 17), and is also coupled to an induction motor (12) through the transmission mechanism, a speed reducer (14), and a clutch (15). A numerical control unit (20) controls the servomotor, the induction motor, and the clutch. After the movable platen, drive by the servomotor, is moved at high speed to a die touch position, the movable platen is driven to a set mold clamping force producing position with a greater driving force, by both the servomotor and the induction motor.

Abstract: A hydraulic clamp unit for a molding apparatus has a pair of opposed complimentary mold halves attached accordingly to a pair of opposed platens suspended on roller guides and moving toward each other into engagement of the mold halves to form a mold cavity surrounding a molded article of a thermoplastic material. The unit is provided with main clamp cylinders of a pull type and having piston rod chambers pressurized to exert pressure on the platens during formation of the article. Rapid movement of the platens is achieved by means of kicker cylinders having piston chambers and piston rod chambers communicating with each other. The main cylinders are locked to one of the platens by means of hydraulic mechanisms.

Abstract: A molding machine which performs molding by means of one mold part held by a fixed platen and the other mold part held by a movable platen movable toward and away from the one mold part. A shaft having an axis extending in the direction of reciprocal movement of the movable platen is disposed on a stationary frame for rotation with respect thereto and for reciprocal movement along the axis of the shaft, and is rotated by an electrical motor. First and second nut members are respectively screwed onto first and second threaded portions formed along the axis of the shaft. The first nut member is secured to one of the stationary frame and the movable platen while the second nut member is capable of being rigidly coupled with the other thereof via a clutch. While the shaft is being rotated, the second nut member is rigidly coupled with the other of the stationary frame and the movable platen via the clutch, a relative movement is produced between the shaft and the first and second nut members.

Abstract: Improved apparatus for plastic molding devices and more particularly for an improved injection plastic molding machine which uses mold inserts carried by pockets in the machinery where a first platen is provided having a first platen pocket to receive a first mold half to be located in communication with a source of plastic material for example thermoplastic material, a second platen having a second platen pocket adapted to receive a second mold half so that the second mold half can be moved to abutting relation with the first mold half to form a cavity defined by the first and second mold halves into which molten plastic material is injected. A source of cooling fluid can be provided through the first and second platen to the first and second mold halves utilizing seal devices between the first and second platens and the first and second mold halves respectively.

Abstract: A straight-hydraulic mold clamping system for use in a molding machine has a bearing portion for a rod of a mold clamp cylinder provided with a plurality of annular oil grooves within which an oil functions, and utilizes the rigidity of the rod so as to horizontally support a movable platen and a molding die attached to the movable platen in a cantilever manner and maintain the horizontality of the movable platen and the molding die.

Abstract: Plastics-forming materials are shaped in a mold tool sealed by an associated closing unit. Lifting elements the stroke of which can be limited and controlled are associated with the mold tool. Shaping is accomplished by filling the mold cavity with reaction mixture while the mold tool halves are not completely sealed, sealing the filled mold and keeping the mold sealed until the article is completely cured. This method and apparatus are particularly useful in the production of dimensionally accurate geometrically complicated shaped articles.

Abstract: A mold opening/closing speed control device wherein an opening/closing speed switching position for molds in a mold clamping unit in an injection molding apparatus can be taught by the control device. The control device is set in a teaching mode (101), a servo motor (M) is driven at a low speed to move (102) the molds, speed switching positions P1, P2 and P3 are stored (103, 104, 205, 106, 109) by a teaching device, and the opening/closing speed control of the molds is performed (110, 123) by the servo motor in accordance with the stored positions.

Abstract: Improvements in differential pressure, thermoforming machinery for molding articles in thermoplastic material wherein a mold station incorporates female mold mechanism and opposed mold mechanism, a web advancing mechanism indexes a plastic web in which products are to be formed between said mold mechanisms, a drive moves the female and opposed mold mechanisms between open and closed positions on opposite sides of the plastic web, severing knife means is cooperable with a final increment of said relative movement to dispose said mechanism in closed position to sever the products formed from the web, and ejector mechanism is operable after severing is accomplished and there has been relative movement of said mold mechanisms toward open position to eject the product.

Abstract: A mold closing unit of an injection molding machine has a hydraulic traveling cylinder and a hydraulic mold closure retention cylinder for the movable mold clamping plate. One-half of a divided injection mold is clamped on the plate and defines with a fixed mold die a mold cavity having a larger volume at the commencement of the mold charge than at the termination of the mold charge. A threaded spindle is engaged with the movable mold clamping plate through a spindle nut, and the spindle is freely rotatable in the stationary mold clamping plate and is connected with a stepping motor. A 4/2-way valve is arranged in the hydraulic supply line leading to the traveling cylinder, and its valve body is axially shiftable on the spindle. The stepping motor is controlled depending on a specified pressure and/or speed pattern as a function of the distance between the mold halves or the mold clamping plates.

Abstract: An injection molding apparatus having movable die operated by a piston and cylinder, includes a hydraulic circuit having a supply line for closing and opening the movable die. A branch line from the supply line leads into a die locking chamber defined between the piston and cylinder, and a first multi-directional control valve is provided for control of the closing mechanism. A second multi-directional valve is located in the branch line for feeding hydraulic fluid into the die locking chamber as sensed by a pressure sensor in the supply line. A threaded spindle meshes with a support for the movable die which feeds back the rate of travel and pressure exerted by the movable die to a stepping motor which varies the spindle rotation in accordance with the rate and the pressure.

Abstract: A control arrangement for moving tools brings these tools quickly into a desired position smoothly and without shock. The arrangement comprises means for preadjusting the required displacement so that the whole displacement path corresponding to the movement sweep of the tool is first determined. A calculation member (4) converts a given delay of the tool movement into a value corresponding to the speed of movement. An integrator (6) derives from the calculated speed value as a function of time a required position value. Upon movement of the tool the means for preadjusting the required displacement are continuously readjusted and the adjusted value for the drive (25) is determined by means of a comparison with the position value supplied by the actual displacement pick-up device (8).

Abstract: A mold closing unit of an injection molding machine has a threaded spindle which is engaged with the movable mold clamping plate of the machine via a spindle nut. The spindle is attached to the stationary mold clamping plate of the machine in a freely pivotable manner, and is connected with a stepping motor by means of a coupling. The stepping motor is controlled depending on a specified speed pattern as a function of the distance between the mold halves of the mold clamping plates. The valve body of a 4/2-way valve engages the spindle for relative axial movement and controls the hydraulic operating medium for the mold closing unit. A switch is arranged in the casing of the valve which can be triggered by the coupling and which actuates, for example, an indication system when a mold closure security error occurs.