Abstract: A hydraulic actuator assembly for a push-type die closing unit of an injection molding machine which has a central, internally bypassable power piston, lateral cylinders for rapid opening travel and a rearward stationary plunger for rapid closing travel, the lateral travel cylinders and the pressure spaces of the power cylinder creating a differential effect under which a small external flow volume of pressurized fluid is required from the pump to produce rapid opening and closing travel while a much larger internal flow volume passes through a flow connection between the cylinders. A program-controlled proportional-response throttle valve in this flow connection gives an accurate and steady control over the travel speeds, especially during deceleration. The throttle valve also makes it possible to obtain a forcible initial die opening movement.

Abstract: A vane-type rotary actuator in which a disc like seal member made of an elastic material with a hole provided in the middle thereof is pressed in place in contact with a flange surface. With seal material thus somewhat deformed in the radial direction thereof, pressure required for sealing is generated at the inner surface of a cylinder and the outer surface of a shaft cylinder.

Abstract: A sequencing valve mechanism utilized to control a pneumatic or hydraulic pressure medium from an on/off type pressure source to a two-chambered pneumatic or hydraulic appliance is disclosed. A pawl on a ratchet arm is driven around a ratchet island by the alternate application and withdrawal of pressure to the sequencing device. The ratchet arm is pivotally attached to a valve control arm which regulates a valve so as to control the output of a pressure source. The shapes of the ratchet island portions are such that two alternate applications and withdrawals of pressure are required for the pawl to complete one cycle about the island and, thereby, actuate the valve to different output positions only on alternate applications of pressure to the sequencing device.

Abstract: A hydraulic drive system for civil engineering and construction machinery in which at least first and second hydraulic circuits having at least first and second hydraulic pumps, respectively, are provided for driving a plurality of actuators such as left and right travelling actuators, a boom actuator and an arm actuator. The first circuit includes a first travelling directional control valve for one of the left and right travelling actuators located downstream of a first boom directional control valve for the boom actuator and a first arm directional control valve for the arm actuator that the latter to receive a hydraulic fluid supply from the first pump by taking priority over the first travelling valve.

Abstract: A self-leveling series type hydraulic system with a float position including boom and bucket valves which separately control boom and bucket cylinders and a flow divider valve positioned in the exhaust flow path from the rod end of the boom cylinder. The flow divider valve in one position splits the flow sending a portion of it to the cap end of the bucket cylinder so as to maintain the bucket in a level condition during raising of the boom with the remaining flow returning to the control valve downstream of the boom valve whereby the bucket valve can be separately actuated concurrent with the boom valve and supplied with oil so as to override the self-leveling function if desired. The flow divider valve having a second position which bypasses all of the flow from the boom cylinder to reservoir when the boom control valve is in a float position.

Abstract: A porting and ducting arrangement for a pair of adjacent hollow cylinders includes respective pluralities of passages extending longitudinally in the walls of the cylinders. Each passage is provided with a port in communication with the interior of the associated cylinder. Plural recesses in the end of the cylinders or in a cover are each in communication with a separate passage or group of passages when the cover is applied to the cylinders. There are a pair of such recesses thereby associated with each cylinder and at least one recess of each pair is in communication with a recess of the other pair via duct means in the cover. Gasket means is retained between the cylinders and the cover to seal each recess of each pair of recesses with respect to the other recess of the pair.

Abstract: Separate branch conduits extend from a common pump to two fluid power operated systems. One of the branch conduits supplies a relatively low volume of fluid through a pilot flow conduit to a steering control valve in one of the systems to adjust its operating pressure when the steering control valve is displaced from its neutral position. The other branch conduit delivers pressurized fluid directly to the steering control valve on a priority basis. A pressure regulating valve connected between the other branch conduit and the pilot flow conduit isolates the steering system from a higher pressure in the other fluid power operated system and adjusts the operating pressure in the steering system to meet steering load demands.

Abstract: A continuously variable transmission (2) is constructed utilizing a constant displacement pump (4) of fixed fluid power stroke, rather than a variable displacement pump with a variable pump stroke. A fluid motor (14) is driven by the pump and has an output stroke. Means (22) are provided for varying the output stroke without varying the input power stroke.

Abstract: Pipe thrust-jacking apparatus includes a pressure ring 5 which is advanceable by a plurality of hydraulic rams 3. The rams are controlled by hydraulic control means having a plurality of hydraulic control valves 19. Each control valve is associated with a respective hydraulic ram, and is connected to a first input line and to a second input line. Each of the first input lines is connected to a respective hydraulic fluid feed line 9, and each of the second input lines 17 is connected to a common hydraulic fluid supply line 11 and to an auxiliary pump P2. The common supply line is connected to all of the feed lines. Means 12,15 are provided for selectively connecting each of the hydraulic control valves to its first input line and/or its second input line.

Abstract: A blow-out preventer for attachment with a tubular member of a well for containing well pressures within the well as needed, having a body adapted to receive a ram body mounted therein for movement between an open and closed position. The preventer further includes an actuator body member mounted with the body adjacent the ram bore and having urging means therewith for urging the ram body between such open and closed positions and alignment means with the actuator body member and the ram body for ensuring proper alignment and positioning of the ram body with respect to the ram bore and the axial bore of the tubular member. The actuator body member has fastening means that fits into connecting means in the preventer body. The two bodies are secured by securing means installed in said connection means and engaging said fastening means.

Abstract: An expansion device for converting changes in fluid pressure to displacement of a moving machine part or converting displacement of a moving part to changes in fluid pressure, the device featuring a first flexible expansion chamber wall at least partially defining a first expansion chamber region, a first rigid member having a convex surface supporting the chamber wall, a second rigid member having a concave surface facing the convex surface and movably mounted relative to the first rigid member to cause, when the first and second rigid members move together, the wall to fold over so that a portion of the wall's inner surface changes from an expanded concave shape to a convex shape adjacent to the first member, and a displacement connector attached to one of the first and second rigid members for connection to a moving machine part.

Abstract: A combined brake cylinder/air reservoir device in which a relatively small, tubular-shaped piston in a positioning chamber is connected to a larger power piston having an application chamber on one side and a release chamber on the other side in which air is stored in place of separate reservoirs. A replaceable cylinder liner is provided to receive different-sized power pistons. During a brake application, the power piston enters the cylinder liner and is displaced from the liner during brake release to provide free air flow between the application and release chambers and thereby facilitate piston return movement by means of a return spring. A dynamic pressure seal between the application chamber and positioning chamber engages the outer periphery of the tubular-shaped small piston, while a smaller diameter dynamic pressure seal between the release chamber and atmosphere engages the inner periphery of the tubular-shaped small piston.

Abstract: A fluid servo actuator control/damping mechanism and method which utilize and combine the functions of an electro-mechanically driven servo valve to achieve ram or actuator fluid flow and load control even after loss of fluid power as well as the main ram position control function under normal operating conditions.

Abstract: A pressure fluid cylinder without a piston rod and of the kind having a slotted cylinder tube (1) and a piston displaceable therein, said piston being connected to a movement transfer device, which extends radially through the slot. The slot is sealed axially on each side of the piston by means of internal and external sealing strips (31,32) consisting of a flexible sealing band (37, 38) as well as retention means (44,45) extending into the slot and securing a releasable mechanical engagement with each other or, by friction, with the side walls of the slot.

Abstract: A wheel cylinder assembly has telescoping brake actuating pistons with a brake pressure proportioner in the larger actuating piston to proportion brake actuating pressure.

Abstract: An assistor for reducing stepping force of a clutch pedal, in which a push rod is inserted into an assistor casing freely movably in the axial direction, a casing outside end of the rod is interconnected to a clutch pedal, a casing inside portion of the rod is provided with a piston which divides the casing into first and second chambers, the first chamber intercommunicates with atmosphere, the second chamber intercommunicates freely changeably with atmosphere and a negative pressure source through a change-over valve mechanism, and the piston is interlocked with the change-over valve mechanism through the means of a negative-pressure setting spring so that negative pressure for reducing stepping force can be fed into the second chamber according to a shifted length of the rod.

Abstract: A hydropneumatic suspension unit includes a large diameter flanged road arm spindle which is bolted to the vehicle hull; a road arm has one end rotatably mounted on the road arm spindle and another end mounting a road wheel; a barrier fluid sealed piston is reciprocated relative to a road arm bore to seal an in-arm mechanically operated pneumatic spring which has a gas volume trapped by the barrier fluid sealed piston to support the sprung mass of the vehicle; the sealed piston is defined by a pair of spaced seals and an oil chamber which has an oil charge therein pressurized by preload spring on the piston to displace the oil barrier to both lubricate and preload the pair of spaced seals as the piston is dynamically operated to vary gas compression and produce a resultant pressure on the piston to counteract vertical forces on the road wheel.

Abstract: A hydraulic ram for use as an advance ram in mining operations has a plurality of permanent magnets embedded in its piston rod. At least one sensor is associated with a guide bush fixed to the piston rod end of the cylinder of the ram. The or each sensor is accommodated within a respective pocket formed in the guide bush. The pocket(s) can be closed off by a detachable closure member.

Abstract: An air driven diaphragm pump having an actuator valve for converting a source of compressed air into a reciprocating drive. The actuator valve includes a valve piston for alternately directing air to one side or the other of the pumps, a control rod fixed to the reciprocating elements of the pump and means for shifting the valve piston responsive to the position of the control rod. An axially spaced bifurcated inlet is employed to provide additional energy to the shifting of the valve piston. The valve piston also is arranged to cover vent ports as a mechanism for closing off all compressed air under stalled conditions of the pump.

Abstract: An oscillator is proposed which comprises a pair of cylinders having a common, circular-cylindrical outer wall (100) and two sealingly guided pistons (120, 122) each having one piston rod (121, 123), which are likewise guided in a sealing manner to the outside through the closure walls of the cylinder. The cylinder is divided by the pistons (120, 122) into outer chambers (124, 125) and inner chambers combined into one common chamber (126). The chamber (126) is filled with fluid. The outer chambers (124, 125) have two openings (102, 103) offset from one another by 180.degree.. A control cylinder (101) having axially offset, oppositely disposed holes (104, 105, 106, 107) connects the outer chambers in alternation with an annular high-pressure chamber (113, 115) and an equalization chamber (114) whenever the control cylinder (101) is rotated. The two pistons (120, 122) thereby execute movements in common toward the left or right, respectively.