Abstract: A molding injection pressure and a molding clamping force are determined in advance to obtain a parting opening amount, which is a predetermined gap, between a movable mold and a fixed mold of a mold during injection filling.

Abstract: A pneumatic system controlling a bath crust breaker includes a cylinder defining a piston chamber. A piston is slideably displaced within the cylinder by pressurized fluid directed to either a piston chamber first portion with respect to the piston or a piston chamber second portion oppositely positioned about the piston. A pneumatic valve system includes a first control valve aligned between first control valve first and second positions, the first control valve first position aligned with the first portion, and in the first control valve second position is aligned with the second portion. A second control valve is aligned between second control valve first and second positions. An orifice between a pressure source and first control valve is sized to control fluid flow rate so a pressure reached in either the first or second portion during a crust breaking cycle is less than a pressure source maximum pressure.

Abstract: Methods and apparatus to control movement of a component are disclosed herein. An example apparatus includes a housing defining a bore and a piston disposed inside the bore. The piston is to be coupled to a movable component disposed outside of the bore. The example apparatus further includes a fluid flowline in fluid communication with a first chamber of the bore and a second chamber of the bore. The first chamber is on a first side of the piston, and the second chamber on a second side of the piston. The example apparatus also includes a valve to control fluid flow through the fluid flowline. The valve is to be in a first state to enable the piston to dampen movement of the component, and the valve is to be in a second state to enable the piston to hold the component substantially stationary.

Abstract: Adjustable-height column, especially for chairs, includes a guide tube and a pneumatic, selectively blockable piston-cylinder unit for height adjustment located in the guide tube. The piston sealingly subdivides the cylinder into two operational chambers. Beginning at a defined retracted setting of the piston-cylinder unit, the blocking function is compulsorily canceled, in that a fluid flow connection between the two operational spaces is established which overrides the blocking function. An additional spring element is placed in series with the piston-cylinder unit to prevent a sudden collapse of the column.

Abstract: The invention concerns a device in an piston cylinder aggregate including a valve element (8) which comprises a valve body (9) for choking the flow in a fluid channel (6) in co-operation with a valve opening (7), wherein the device is arranged in a bore (11) in an end wall (1) of the piston cylinder aggregate and wherein the valve element (8) is provided with a setting means (10) to allow adjustment from the outside of the end wall.

Abstract: It is intended to dispense with the pipe welding work, thereby improve the pipe mounting performance and prevent contamination which results from welding, and elimination the waste of oil.A spigot portion 34 is mounted upright integrally in the center of the upper end portion of a piston 17, the base end of a piston rod 18 is fitted on the outer periphery of the spigot portion 34, and the outer periphery of the base end of a pipe 41 is press-fitted into an upper hollow part of the spigot portion 34.

Abstract: A system and method for controllably positioning a hydraulic actuator which is operably connected to a control surface includes at least one main control valve for controlling the hydraulic pressure supplied to the actuator in response to a control signal indicative of a predetermined actuator position and at least one parallel control valve for supplying additional hydraulic pressure to the actuator in response to an error signal indicative of the difference between the position of the actuator and the predetermined actuator position to thereby correct for any differences indicated by the error signal. By correcting for any differences indicated by the error signal, the errors in positioning the control surface can be decreased and the stiffness of the control surface can be increased.

Abstract: A linear drive comprising a drive member adapted to be reciprocated axially in a housing between two end positions. Opposite to the former there is a wall on at least one axial side. There are means to reduce the impact in the end position, such means having an annular lip. The lip is arranged on the drive member or on the wall and respectively faces the wall or the housing. The lip defines a damping space which is open on an impact side. If the drive member approaches one end position thereof, the damping space is occluded and reduced in volume so that some trapped fluid will escape via a relief opening so that there is a braked part of the stroke. Using simple means it is therefore possible to provide an extremely efficient fluid damping at the end position.

Abstract: Piston sealing and dampening device in a pressurized-fluid cylinder, where a piston (3) has a central recess (3a) facing towards a cylinder end cap (1a) and disposed such that when the piston is in the vicinity of its end position, said recess accommodates a sleeve portion (5) provided with an internal pressurized-fluid connection (6) and projecting from the cylinder end cap. An integrated sealing ring (10) seals against the outside of the sleeve portion (5) with an inner sealing ring lip (10e) and against the inside of the cylinder tube (2) with an outer sealing ring lip (10c).

Abstract: The invention relates to piston and cylinder unit with a regulating valve for controlling the speed of the piston. The regulating valve has an open position in which it allows free passage of a fluid to the piston and a choking position in which it reduces the rate of such flow for influencing the speed of the piston. Furthermore there is at least one sensor responding to a given position of the piston and designed to change over the setting of the regulating valve. The sensor is an inductive, electrical or magnetic contactless sensor. The regulating valve has a setting unit electrically operated by the regulating valve so that the regulating valve is switched between its open and choked positions.

Abstract: The drive system for cells for fused salt electrolytic production of aluminum is supplied with compressed air via a compressed air network with compressor and compressed air reservoir. It comprises at least one working cylinder with piston and piston rod, a slide valve situated after the junction from the compressed air network, compressed air pipes and a microprocessor. During the thrust movement in the normal work cycle, the working cylinder forms a circuit together with a 5/2 channeling valve, a 3/2 channeling valve and the related compressed air pipelines; the said circuit is fed compressed air via a pressure reducing valve and the compressed air pipeline running from it. By briefly switching over the 5/2 channeling valve normal pressure can be employed and the positive chamber of the working cylinder evacuated, as a result of which the thrusting force supplied by the system can be greatly increased.

Abstract: The drive system for cells for fused salt electrolytic production of aluminum is supplied with compressed air via a compressed air network with compressor and compressed air reservoir. It comprises at least one working cylinder with piston and piston rod, a slide valve situated after the junction from the compressed air network, compressed air pipes and a microprocessor. During the thrust movement in the normal work cycle, the working cylinder forms a circuit together with a 5/2 channeling valve, a 3/2 channeling valve and the related compressed air pipelines; the said circuit is fed compressed air via a pressure reducing valve and the compressed air pipeline running from it. By briefly switching over the 5/2 channeling valve normal pressure can be employed and the positive chamber of the working cylinder evacuated, as a result of which the thrusting force supplied by the system can be greatly increased.

Abstract: Initiation of piston movement in a fluid actuator and sustained piston movement at a controlled rate are achieved by control of servo pressure in the actuator.

Abstract: A fast opening valve apparatus includes an electronic sensing circuit to determine when a positional error signal exceeds a predetermined reference value corresponding to an opening rate reference value. The sensing circuit provides a fast open command signal which is applied to a solenoid valve which is hydraulically coupled in parallel with a control servo valve. The control servo valve hydraulically couples a primary source of hydraulic fluid under pressure to a valve actuator which is mechanically coupled to a valve stem of an associated steam valve desired to be controlled. The activated solenoid valve opens a supplemental hydraulic fluid path between the valve actuator and the primary source of hydraulic fluid. To ensure an adequate hydraulic fluid pressure at the input of the servo valve and solenoid valve, an auxiliary source of hydraulic fluid under pressure may be coupled upstream of the servo valve and solenoid valve.

Abstract: This invention relates to direct acting rotary actuator cylinders wherein the linear motion of the piston is directly converted to angular motion by a means completely enclosed within the cylinder, which means comprises a slidable partitioning body engaging the circular cylindrical cavity in the cylinder in an air-tight sliding relationship and a circular cylindrical rod coaxially and rotatably disposed in said circular cylindrical cavity having a mid-section with a noncircular cross section of a diametrical dimension greater than the diameter of said circular cylindrical rod.

Abstract: The operator of a lift truck or other load supporting vehicle (11) having a tiltable mast (12, 12a) is alerted as the mast (12, 12a) tilts beyond a predetermined orientation by a temporarily slowing of the rate of tilting movement. Return motion of the mast (12, 12a) may be unimpeded. The operator is reliably made aware when the mast (12, 12a) reaches a predetermined limit but may continue the tilting motion when that is necessary for such purposes as traveling the vehicle (11) under overhead obstructions. In systems where the mast (12, 12a) is tilted by fluid motors (20, 20a), the automatic tilt speed reduction may be realized with a valve (33, 33a) which temporarily introduces a one way flow restriction (49) into the fluid flow path (28, 28a) between the motors (20, 20a) and pressurized fluid source (27, 27a), the valve (33, 33a) being actuated by inclination sensing mechanism (23, 23a).

Abstract: An improved fluid actuating device for an electric switching apparatus such as a high-voltage power circuit breaker or the like includes an actuator for actuating the electric switching apparatus. The actuator has a cylinder and a differential piston movable in the cylinder between first and second end-positions corresponding to the open and closed positions of the switching apparatus. The differential piston has two end-faces for receiving fluid pressure force. One of the two end-faces has a surface area greater than the other one of the two end-faces. A high-pressure fluid supply supplies fluid to the two end-faces and a valve alternately interrupts and passes the fluid from the fluid supply to the one end-face whereby the differential piston is caused to move from the first end-position to the second end-position when the valve passes fluid to act upon the one end-face of the piston.

Abstract: In an injection molding machine of the type comprising an injection cylinder, a feedback circuit for feeding back the oil in the rear chamber of the injection cylinder into the front chamber thereof and a booster cylinder, a pressure oil accumulator is connected to the booster cylinder through a valve for supplying pressurized oil for actuating the booster cylinder. A check valve is connected in parallel with the valve. When water hammer occurs at the end of the injection stroke the check valve opens to absorb the energy of water hammer by the accumulator.

Abstract: This invention is directed to fluid actuated apparatus for automatically restricting the flow of fluid in conduits leading to and/or from fluid actuated cylinder means for causing pivotal movement of a member, such as the turret carrying the boom and bucket of a backhoe, so that the speed of pivotal movement of the member is rapid during one portion of its pivotal movement but is automatically reduced during a predetermined portion of its subsequent pivotal movement, thereby minimizing failures of the components of the member and the fluid system and improving the braking action for reducing the speed of pivotal movement of the member. In one embodiment, both the flow of fluid to the operative fluid actuated cylinder and the flow of fluid from the inoperative fluid actuated cylinder are restricted substantially simultaneously by fluid restricting means so that the linear velocities of the rods of both cylinders are reduced substantially simultaneously by the fluid restricting means.

Abstract: An arrangement for controlling a hydraulic motor having a movable member with opposite faces to be impinged by pressure fluid, in which first valve means serve to direct pressure fluid against a respective one of the opposite faces to thus control the direction of movement of the movable member, and in which second valve means connected in a hydraulic circuit with the first valve means serve to control the speed of the motor in connection with control means actuated by the movable member for controlling the change of the speed dependent on the position of this member.

Abstract: A hydraulically actuated control valve normally includes a hydraulic cylinder which has an internal piston connected through a shaft to the actuating mechanism in the control valve. Ports are provided on each side of the piston through which fluid flows to move the piston axially inside the cylinder. The piston can be controlled electrically by an electro-hydraulic servo-controlled valve which includes an electrical input, a mechanical feedback input, and first and second outputs. The outputs are connected to the two ports in the cylinder, a mechanical feedback is coupled to the shaft and the mechanical feedback input of the control valve, and an electrical circuit is coupled to the electrical input of the servo-controlled valve to signal the hydraulic portion of the valve to either move the shaft in a manner to close the valve or move the shaft in a manner to open the valve.

Abstract: A method of injecting a molten material such as molten metal or plasticizing resin under pressure and an apparatus performing the same wherein the piston speed of a cylinder for injecting the molten material is made to decrease before the mold cavity is filled up to the full with the molten material, thereby peak pressure generated in the molten material filled up to the full being eliminated and further pressure vibration occurred in a pressurized oil being obviated.

Abstract: A motor driven by a pressurized fluid medium for operating an impact tool in a linear direction adapted for metal stamping and high velocity milling comprising a housing and a piston unit. The latter comprises a drive piston, a piston rod and a tool. In addition, the motor includes a kinetic energy absorbing device comprising a hydraulic fluid chamber and a retard piston which is rigidly connected to said piston unit and arranged to reciprocate in said fluid chamber. The retard piston retards the piston unit at the end of the strokes only and is freely passed by hydraulic fluid during the working stroke. Cup-shaped means are provided to restrict said by-pass flow of hydraulic fluid at the end of the strokes and thereby protect the motor from excessive stresses during no-load conditions.

Abstract: Apparatus for controlling the stroke of the movable member in a high pressure hydraulic machine, such as a hydraulic press, to permit the member to be positioned to an accuracy of 0.0005 inch and held at such position for a preselected time. The movable member is coupled to a piston movable within a cylinder which receives pressurized fluid. An adjustable threaded rod and nut arrangement is movable by movement of the piston within the cylinder, and an extension of the rod carries an actuating device for sequentially operating a first and then second valve. Operation of the first valve greatly reduces the speed of the movable member and operation of the second valve stops the movable member at its exact predetermined position. An adjustable time delay is coupled with the output from the second valve to maintain the movable member at such position for a preselected time thus maintaining the pressure on the article being formed in the machine.