Abstract: The present invention relates to a servo hydraulic press for sheet metal forming. The press comprises a hydraulic cylinder, at least two servo motors and at least two pumps for supplying pressurized fluid to the hydraulic cylinder, where each servo motor drives at least one pump. The servo motors are operable at variable speed, and the first servo motor and first pump are operable in an opposite direction to the second servo motor and the second pump. With this arrangement, the servo hydraulic press may be operated at low speed without causing damage to the pumps or motors.

Abstract: A swing lever assembly includes a unitary body. By providing a unitary body for the swing lever assembly the number of elements is substantially reduced which solves the problems stated above. In an exemplary embodiment, the swing lever assembly includes a limited number of components. Further, the swing lever assembly includes a limited number of installation components.

Abstract: An energy-recovery generation system for a handling and carrying electric vehicle, comprising a hoisting cylinder (9), wherein an output pipeline of the hoisting cylinder (9) is provided with a pressure sensor unit (1) and a directional valve (2); the directional valve (2) is under the control of the pressure sensor unit (1); a first outlet of the directional valve (2) is connected to a tank (5) through a way of a multi-way valve (4) with an operating handle; the pressure oil, flowing out from a second outlet of the directional valve (2), passes through a pump (7) having an oil suction port capable of bearing pressure or a motor, and then passes through the multi-way valve (4), to finally flow back to the tank (5); the pump (7) having an oil suction port capable of bearing pressure or the motor drives an electric motor (16) to output electric energy; an electric energy output end of the electric motor (16) is connected to an energy storage device (20) through a converter (21).

Abstract: In a mechanical press, the pressure (cylinder force) of a hydraulic pressure chamber of a cylinder-piston mechanism provided in a slide of the mechanical press can be variably controlled with a high responsiveness by a hydraulic pump/motor driven by an electric servomotor, in response to a cylinder force command corresponding to the press load command. Accordingly, even if a die height value is set to a value small enough to cause an overload, the press load can be restricted before the occurrence of the overload, and this can save the trouble of strictly adjusting the die height value. Further, pressure-application time in the vicinity of a bottom dead center can be lengthened, and a breakthrough phenomenon can be suppressed from occurring at the end of pressure application. Still further, because the overload does not occur, pressure oil is not relieved, so that the interruption of a press operation is avoided.

Abstract: A grill includes a lower platen assembly having a lower grilling surface and a pivotally attached upper platen assembly having an upper grilling surface. The upper platen assembly includes three motors encased in a shell. A cable attached to each motor suspends the upper grilling surface. The grill is automatically calibrated to ensure that the upper grilling surface is level. Each motor independently and sequentially raises the upper grilling surface from the lower grilling surface. When the upper grilling surface lifts from the lower grilling surface, the current in the motor changes. The settings of each motor at this instant are stored in a control to determine the calibration point when the upper grilling surface is level. The grill also automatically recognizes a food item placed on the lower grilling surface to determine the cooking parameters of the grill.

Abstract: The present invention relates to a device and a method for cooking food on a grill having opposed upper and lower platens wherein a gap spacing between the platens is adjusted in an initial stage and in subsequent stages of the cooking time for the meat. The method includes causing the food to be located between two opposed platens, the opposed platens each having opposed cooking surfaces and the opposed cooking surfaces defining a gap spacing that is adjustable, and adjusting the gap spacing between the platens so that during an initial stage of the cooking the gap spacing is equal to or less than the nominal initial uncooked thickness of the food, and during one or more subsequent stages of the cooking, after the initial stage, the gap spacing between the platens is varied.

Abstract: A device for reducing the press angle control error caused by press load variation, where the device includes: a reference value output unit that outputs a press angle reference value, a press angle detection unit, a speed command unit, and a driving unit. The press angle detection unit detects a press angle of the corresponding press machine and outputs a press angle detection value. The speed command unit outputs a command speed value of a motor of the corresponding press machine based on the press angle reference value and the press angle detection value. The driving unit controls the motor speed of the corresponding press machine based on the command speed value. The device further includes a correction unit that corrects the press angle reference value or the command speed value so the difference between the press angle reference value and the press angle is within a predetermined range.

Abstract: An injection molding machine that can prevent a stationary platen and a mold attached thereto from being tilted by applying a nozzle touch force. A connection part is mounted on a stationary platen via a connection pipe. The connection part is mounted on a connection mechanism via a block. A ball screw shaft as a nozzle touch drive mechanism is rotatably mounted on the connection mechanism. The block is adjusted for a mounting position thereof such that tilt in the stationary platen and a mold attached thereto is eliminated when the mold is attached to the stationary platen and a nozzle touch force is applied to the mold. The nozzle touch force prevents the stationary platen and the mold from being tilted.

Abstract: A control apparatus of a press machine in which a motor performance torque is fluctuated in accordance with a rotational angle of the rotating body in the case of rotating the motor at a fixed instruction speed. The control apparatus includes an angle detecting apparatus detecting a rotational angle of the rotating body, a torque determining apparatus determining a necessary motor torque in correspondence to a characteristic of the press machine on the basis of a value of the rotational angle input from the angle detecting apparatus, and a speed adjusting apparatus increasing the rotational instruction speed of the motor to a value more than the fixed instruction speed, at the rotational angle of the rotating body in which the necessary motor torque becomes smaller than a predetermined motor torque reference value.

Abstract: A press specially adapted to compress a stack which includes one or more pressure sensitive based fastening layers which are actuated by application of substantial pressure. A lower press plate includes a receiving surface upon which the stack is positioned and first and second guide members, with the receiving surface being tilted with respect to a level plane such that the stack tends to move on the receiving surface towards the two guide members. An upper press plate is provided which includes a compressing surface which is substantially parallel with respect to the receiving surface when the press is in a first operating mode. A drive mechanism is provided for driving the lower and upper press plates towards one another so as to applying a compressing force to the stack.

Abstract: There are provided a device and a method capable of reducing a press angle control error caused by a press load variation and of preventing a press load variation of one press machine from acting on the other press machine. The device includes: a reference value output unit 25 which outputs a press angle reference value; and a press angle detection unit 27, a speed command unit 29, and a driving unit 31 which are provided for each press machine. The press angle detection unit 27 detects a press angle of the corresponding press machine and outputs a press angle detection value. The speed command unit 39 outputs a command speed value of a motor of the corresponding press machine on the basis of the press angle reference value and the press angle detection value. The driving unit 31 controls a speed of the motor of the corresponding press machine on the basis of the command speed value.

Abstract: A cotton module building apparatus, utilizing imaging apparatus operable for capturing real-time images of the module building process, including accumulated cotton in the module building chamber, cotton inflow, and the in-process cotton module, and a method for building a cotton module using the images. The imaging apparatus includes a camera or cameras disposed at advantageous locations about the module building chamber, and cotton is distributed and moved within the chamber responsive to the images, for advantageous placement and distribution for forming a module having a desired consistency and top shape. Imaging apparatus can also be provided for observing unloading of a module from the chamber, and for facilitating maneuvering and positioning the unloading apparatus.

Abstract: A high-pressure press includes a pressure vessel surrounded by a force-absorbing press frame. The high-pressure press also includes a detection structure for detecting changes in length of at least one column comprised in the press frame, the changes in length depending on the pressure inside the pressure vessel. The detection structure includes a limit switch, which is adapted to detect if the change in length of the column has reached a threshold value and, in that case, interrupt a pressing operation in progress and reduce the pressure inside the pressure vessel.

Abstract: A pressing apparatus using a motor, in which a driving device for fast feed, which lowers a upper die to a position immediately before pressing, and a motor for pressing, which performs a pressing operation, are used to cause the driving device for fast feed and the motor for pressing to operate cooperatively, and only one position detector, which detects a present position of a slider, is provided for a set of the driving device for fast feed and the motor for pressing. A lock device is provided so as to lock the slider and the screw shaft while the motor for pressing is operating for pressing a work piece.

Abstract: In a press device for pressing a slider with a plurality of motors as driving sources, pressing is performed while a slider is kept horizontal even if an eccentric load is applied.

Abstract: A press comprises a servo motor (6), a ball screw (9), and a roller guide (11) in which machining accuracy is enhanced while reducing the overall size and weight, noise and vibration, and power consumption of the press.

Abstract: A high-pressure press includes a pressure vessel surrounded by a force-absorbing press frame. The high-pressure press also includes a detection structure for detecting changes in length of at least one column comprised in the press frame, the changes in length depending on the pressure inside the pressure vessel. The detection structure includes a limit switch, which is adapted to detect if the change in length of the column has reached a threshold value and, in that case, interrupt a pressing operation in progress and reduce the pressure inside the pressure vessel.

Abstract: A press forming method is disclosed, wherein press forming can be effected at high speed while maintaining the horizontal state of a slide plate in press-forming a work-piece by a press machine. A press machine is used in which the slide plate is pressed by a plurality of drive sources using servo-motors for driving. The speed of one of the plurality of drive sources is set to a target speed for production forming for the drive source, and by using a function that shows a delay in terms of a speed of the drive source and a load thereon and also using a load separately found, the respective speeds of the drive sources are found so as to eliminate the delay between the drive sources. Trial forming is repeated on the basis of the thus-found speed to derive conditions that enable press-forming at high speed while maintaining the horizontal state of the slide plate.

Abstract: A press forming machine comprising driving shafts for pressing three or more respective pressure points and displacement measuring means for measuring a displacement close to the pressure point. A central driving shaft among the driving shafts has a gap (the slack) larger than those of other driving shafts between each of the driving shafts and a pressure plate. During press formation at a trial stage, a positional displacement close to each pressure point is measured by the displacement measuring means and control data is supplied to each driving source for driving a driving shaft to drive the pressure plate. Then, production press-formation is performed in accordance with the above result. Therefore, the central driving source can avoid overload by the slack of the driving shaft with the pressure plate.

Abstract: A press forming machines includes displacement measuring means for measuring a displacement between a slide plate and a reference plate. Control means measures a positional displacement of each of the driving sources by using the displacement measuring means in each of a plurality of operating steps during the molding operation, detects a desired displacement position of the entire slide plate, extracts control data including a correction amount to maintain the entire slide plate at the desired displacement position, the correction amount corresponding to a change in load on each of the driving sources, stores the control data in the memory, supplies the control data to the driving sources, and separately drives the driving sources. Since an actual molding operation can be performed using control data generated in a trial molding operation, the cycle time of the actual molding can be shortened.

Abstract: A fault tolerant operating method for a cotton compactor of a cotton module builder or packager of a cotton harvesting machine, which serves as an alternative to shutting down the compacting process or erratic operation thereof, in the event of indication of a fault or failure condition involving one or more sensors associated with the compactor, or a conductive path in connection with a sensor, all generally identified as a fault or failure condition.

Abstract: A press forming method is disclosed, wherein press forming can be effected at high speed while maintaining the horizontal state of a slide plate in press-forming work by a press machine. A press machine is used in which the slide plate is pressed by a plurality of servo-motor drive sources. In trial forming, the slide plate is sufficiently slowly moved to measure the delay of each drive source. According to the magnitude of the delay of each drive source or according to the difference between the trial forming speed and the production forming speed, the respective speeds of the drive sources are corrected, and trial forming is repeated on the basis of the corrected speed to derive conditions that enable press forming at high forming speed suitable for mass production while maintaining the horizontal state of the slide plate to the extent of ensuring sufficient product accuracy.

Abstract: An apparatus and method for cotton module building utilizing one or more augers on a compactor frame movable for compacting cotton in a cotton compacting chamber of the module builder. The auger or augers are rotatable for moving accumulated cotton in opposite directions therein, and are tiltable by contact with cotton accumulated unevenly in the chamber. A position or positions of the auger or augers are sensed for detecting tilting of the auger or augers. A controller responsively controllably operates the auger or augers for moving cotton in contact therewith in an appropriate direction for reducing the tilting and more evenly distributing the cotton. The cotton can then be compacted into a cotton module having desired dimensions.

Abstract: A press forming machine having a slide plate which reciprocates by driving sources between a lower support stand and an upper support plate and has a forming space between the lower support stand and the slide plate. In the press forming machine, a reference plate for a displacement reference for the slide plate is supported on the lower support stand. The driving sources are engaged with the slide plate by the drive shafts of the driving sources to drive and press the slide plate. The drive shaft is provided with a through hole axially extending in a shaft center thereof, and displacement measuring devices each for each of the drive shafts measures the displacement of the slide plate portion corresponding to the through hole with respect to the reference plate, through the through hole. As a result, the displacements at the pressurized points on the slide plate can be measured.

Abstract: In a press forming machine for pressing a slide plate, which has a movable mold thereon, by using a plurality of driving sources, a control unit is disclosed, in which when offset load is applied on the slide plate, molding can be performed while the slide plate is maintained at a desired position relative to a fixed mold. In the press forming machine, engaging parts corresponding to the driving sources are provided on the slide plate, and displacement measuring units for measuring a displacement of the slide plate are provided near the engaging parts.

Abstract: Method and apparatus for registering and bonding upper and lower substrate plates together through a sealer material and in such a way as to form a gap of a predetermined width between the two substrate plates. Registered substrate plates are provisionally pressed to form a joined substrate assembly, which is then pressed under heated conditions at a hot press station, thereby compressing the sealer material into a flattened form and at the same time thermally hardening the sealer material to form a predetermined gap space between the two substrate plates. In order to correct positional deviations which occur to the upper and lower substrate plates in the course of the hot pressing, on the basis detected positional deviations of upper and lower substrate plates of a hot-pressed substrate assembly, upper and lower substrates are set in offset positions instead of aligned positions when registering them at the provisional press station to cancel predicted positional deviations at the hot press station.

Abstract: Disclosed are a slide inclination correcting method and a slide inclination correcting apparatus in press machinery having a slide drive mechanism disposed in a top area of a press machine for driving a slide via a plurality of points to vertically move it up and down, thereby forming a work piece. According to the invention, the method and apparatus include the steps of, and means for, finding by measurement or computation for each of dies or die sets an eccentric load that is to develop in the slide in the process of forming a work piece to prepare a die based slide inclination correcting data for each of the dies or die sets; and on the basis of the die based slide inclination correcting data prepared, pre-imparting to the slide a compensatory amount of inclination which corresponds to a predicted amount of inclination caused the slide due to the eccentric load found.

Abstract: Disclosed are a slide inclination correcting method and a slide inclination correcting apparatus in press machinery having a slide drive mechanism disposed in a top area of a press machine for driving a slide via a plurality of points to vertically move it up and down, thereby forming a work piece. According to the invention, the method and apparatus include the steps of, and means for, finding by measurement or computation for each of dies or die sets an eccentric load that is to develop in the slide in the process of forming a work piece to prepare a die based slide inclination correcting data for each of the dies or die sets; and on the basis of the die based slide inclination correcting data prepared, pre-imparting to the slide a compensatory amount of inclination which corresponds to a predicted amount of inclination caused the slide due to the eccentric load found.

Abstract: A press for fabrication of building components including: an upper platen; a lower platen; the upper platen and/or lower platen movable towards and away from the other; a first and second hydraulic device located on a base, each hydraulic device including; a cylinder; a piston located in the cylinder defining a first and a second chamber in the cylinder, the piston sealingly engaging the cylinder and movable in the cylinder; and a piston rod connected to the piston and extending through the second chamber to engage the upper or lower platen; a pump to pump hydraulic fluid into the first chamber of the first hydraulic device; and a valve in fluid communication with the first chambers of the first and second hydraulic devices to selectively withdraw hydraulic fluid from the first chamber of either or both the first and second hydraulic devices to align the upper and lower platens.

Abstract: A feedback control system for use in a press machine is adapted to monitor and adjust the clearance between the gib and slide. A pressurized chamber, such as a hydraulic piston-cylinder combination is disposed in actuating relationship to the gib. Selective pressurization of the piston-cylinder induces a controlled displacement of the gib towards or away from the slide, thereby regulating the spatial relationship therebetween. A sensor provides a measure of any possible clearance between the gib and slide. The clearance measurement is compared to allowable reference data. A controller controls the pressurization of the chamber in accordance with the comparison results, thereby controllably moving the gib. The gib may be selectively displaced to optionally effectuate a minimal clearance condition.

Abstract: A detection system is installed into a press piston guiding area for detecting if the piston guiding system has lost its requisite clearance. The detector is installed in a typical press in such a way that when the negatively grounded press piston touches the detector, it discharges the electrical potential between the detector and the piston. Upon contact, a signaling device stops the press, and a fault is indicated. In an alternative embodiment, the detector senses an eddy current when in close proximity to the piston.

Abstract: A mechanical press having a press deflection controller. The press includes press members which have work surfaces, such as a slide and a bed. The press deflection controller includes a tie rod which is encased in a tube. The tie rod is connected to the press member and is maintained in tension while the tube is maintained in compression. Adjusting the tension in the tie rod during press operation works to adjust deflection in the press member.

Abstract: An apparatus and method for detecting whether platens in a mold clamp remain parallel throughout an entire molding process. The apparatus includes a frame, a first platen having a surface orthogonal to a predetermined axis, a second platen having a surface opposing the first platen, the second platen being reciprocatable along the predetermined axis, actuating cylinders for reciprocating the second platen along the predetermined axis, and positions transducers for electromagnetically detecting the positions of a plurality of points on the surface of the second platen.

Abstract: Method for compacting refuse or waste material in an enclosed baler-compactor, applying controlled angularity of the platen for even compacting and improved distribution of the compacted material in the container of a container-lift assembly. Tying the compacted material into high density bales or bundles for efficient handling and disposal.

Abstract: A method for controlling the drive of a hydraulic press and an associated device for carrying out the method are proposed, the piston/cylinder unit belonging to a press ram being driven via several hydraulic devices connected in series. Depending on the operating phase of the press, the hydraulic devices are here used as required either as hydraulic motors or hydraulic pumps, which effect a delivery of pressure medium into the respective cylinder chamber.

Abstract: A mechanism for closing a mold in plastic injection-molding machinery that accommodates a large and heavy molding tool (5). One stationary chuck (2) rests machinery's base (1), while another chuck (3) travels on a longitudinally movable carriage (4). Each chuck (2,3) accommodates one half of the mold (5) and is aligned by poles (6) which can extend through the chucks. The carriage has a number of bearing sites (4.4) mounted on its bottom surface proximate to its corners. Suspension crossarms (10.2, 14.2) are rotatably mounted to the bearing sites (4.4). The rear suspension crossarms (10.2, 14.2) are mounted using a shaft (11) which has two eccentric portions (11.1) with opposite eccentricities. The non-eccentric portions (11.2) of the shaft are connected to one another by a torsion rod (12) and are rotatably mounted in the bearing sites (4.4). The rear suspension crossarms (10.2, 14.2) are rotatably mounted on the eccentric portions (11.1) of the shaft (11). Rocking shoes (10.1, 14.

Abstract: A bending press is equipped with a movable lower platen actuated by at least three hydraulic jacks, two of which are placed at the lateral ends of the movable platen and at least one of which is placed at the center along the axis of the platen. The hydraulic circuit is associated with a device for detecting the presence of any tilting torque on the movable platen, and with a comparator and computer system connected to the detection device. The jacks are connected to a common directional distributor via pressure control units controlled by the comparator and computer system. This system is capable of producing a continuous reduction in pressure exerted on the jack located on the side opposite to the direction of the tilting torque and possibly also on the jack located at the center so as to produce a torque in opposition to the tilting torque.

Abstract: A press apparatus for use in manufacture of a liquid crystal panel presses upper and lower glass substrates placed between a pressure-exerting plate and a pressure-receiving plate while a seal located around the glass substrates is being heated and melted. The pressure-exerting plate is supported by a pressure-transmitting plate through three load cells. The pressure-transmitting plate presses the pressure-exerting plate against the pressure-receiving plate through the load cells and thereby presses the glass substrates uniformly. When a difference between the detection values of the load cells exceeds a predetermined value, it is determined that the glass substrates are not being pressed uniformly and the pressing operations thus stopped.

Abstract: The upper and lower frames of a folding press include a deflector capable of producing a deflection of at least one portion of a press member. A comparison device is provided which includes two longitudinal bars arranged, respectively, in longitudinal housings of each of the upper and lower frames. One of the ends of each of the bars is secured to its respective housing, the other end of each of the bars being free to move longitudinally in the housings and being connected to a measuring device respectively fixed to each of the upper and lower frames, so as to measure the respective movements of the other ends of the bars in their respective housings in response to any deflection of the upper and lower frames. The comparison device is arranged for controlling the deflector to compensate for any difference in deflection of the frames.

Abstract: Press platens are maintained parallel in critical central regions proximate to a mold between the platens. Leveling cylinders acting between the platens to resist downward action of a central ram on a movable platen. Data identifying expected local platen deflection in response to various operating pressures of the leveling cylinders are recorded. For each leveling cylinder, the current operating pressure is determined and the relative spacing of the platens proximate to the leveling cylinder is sensed. The operating pressures of the cylinders are controlled in response to the sensed relative spacing of the platens and in response to the expected local platen deflection for each leveling cylinder at its current operating pressure to maintain a substantially parallel relationship between the platens proximate to the mold.

Abstract: A mold aligning method and device for a compression molding machine comprising a bed, uprights standing upright on the bed, a crown block joined to the tops of the uprights, a slide block guided for vertical sliding movement by the uprights, and a hydraulic cylinder actuator mounted on the crown block to drive the slide block for vertical sliding movement, for maintaining an upper mold attached to the lower surface of the slide block in parallel to a mating lower mold during a compression-molding operation.

Abstract: A mold aligning method and device for a compression molding machine which includes a bed, a plurality of uprights standing upright on the bed, a crown block joined to the tops of the uprights, a slide block guided for vertical sliding movement by the uprights, and a hydraulic cylinder actuator mounted on the crown block to drive the slide block for vertical sliding movement, for maintaining an upper mold attached to the lower surface of the slide block in parallel to a mating lower mold during a compression-molding operation.

Abstract: A device for resin sealing semiconductor devices includes a pair of chase blocks having cavities for holding semiconductor devices, a press machine for pressing the chase blocks against each other through a pair of press surfaces, a plurality of support members for holding the chase blocks over the respective press surfaces of the press machine and undergoing elastic compressive deformation during the press operation of the press machine, and a plastic injector for injecting plastic into the cavities in the chase blocks.

Abstract: A hydraulic press for compacting materials with a large platen area has a platen support comprising of four hydraulic cylinders, one at each corner of a rectangular or square shaped platen. The cylinders are supplied with near equal fluid flows from commercially available hydraulic flow dividers. When an off-centered platen loading is encountered, the cylinders will respond with a higher restraining force from the cylinders nearest the load with relatively small bending moments transferred to the cylinder rods. The resulting platen structural load resembles a beam supported with pinned connections. The resulting press capacity can be significantly higher than that achievable with guided type platen supports of similar costs where the bending moment is restrained by the stiffness of the guides.

Abstract: A press has upper and lower platens which can be moved towards and away from one another. Four hydraulic leveling cylinders are mounted in a vertical orientation on the lower platen for purposes of platen parallelism control. In preferred form, each cylinder has a piston rod which engages an associated post on the upper platen as the platens approach one another. The piston rod and associated piston are formed with a longitudinal bore open at the upper piston rod end, and a rigid shaft is mounted in the bore with a lower end extending through the bottom of the cylinder housing. A coil spring in the interior of the piston rod urges the rigid shaft upwardly until a collar formed on the shaft engages a stop surface, the upper shaft end then being flush with the upper piston rod end. The associated post is fixed to the upper press platen in-line with the piston rod and has an internal passage in which is located a stud-like shaft that engages the rigid shaft mounted in the piston rod.

Abstract: A press working control method for controlling the press working operation of a press having a pressure cylinder for applying a working pressure to a workpiece, a press slide operatively connected to the pressure cylinder and carrying a movable die, a bed fixedly mounted with a fixed die, a plurality of control cylinders supporting the press slide in a level position during the press working operation, and a press control system for carrying out the press working control method.

Abstract: To crown (deform into a convex state) a die for a press brake (bending press), a number of a pair of upper and lower wedges are arranged between the lower die and the lower table at intervals along the longitudinal direction of the press brake, and simultaneously moved in the lateral direction by an elastic member (plate spring) fitted to each bottom groove formed in the lower wedge. Both free ends of the elastic member is moved by elastic member adjusting means including two sprocket wheels, two tubular nut members, a control motor, etc. To provide a smooth wedge slidable motion, springs are disposed to urge the lower die upward together with a lower die base.

Abstract: A press having a stationary upper bolster and a movable lower bolster carried by two outer and two inner frame plates located near the ends and center of the platens respectively. Through the use of strain gauges measuring the load on the product provided on either sides of each frame plate and servo-operated piston cylinders connected to the lower bolster controlling the output force, a deflection of the lower bolster is made to be parallel to the deflection of the upper bolster so that an equal pressure distribution results in compression therebetween thereby producing a uniform thickness in the product.

Abstract: Molding compound parts with uniform wall thickness are precisely and repeatedly produced by compression, though supporting rods and levelling devices used for supporting the platen of press equipment which tilt during compression. The press equipment of the present invention is provided with levelling devices for supporting the platen at the four corners on the bed. The supporting rods of the levelling devices are hollow, with position detecting means vertically mounted therein so that the height of the supporting rods can be precisely detected and the rods can be synchronously controlled so as to make the upper mold half parallel to the lower mold half of the mold without magnifying the error caused by the inclination of the supporting rods.

Abstract: A hydraulic press having at least two cylinders adapted for providing relative displacement between the upper and lower platens of a hydraulic press, each cylinder being in fluid communication with only one chamber of a multiple chamber hydraulic system utilizing a common ram operating through all chambers, the ram portion in each chamber having a predetermined ratio of area of the ram in the direction of actuation to volume of hydraulic fluid within its chamber to provide equal find displacement in each chamber or movement of the ram.