Abstract: An axial piston machine includes a housing, an actuating piston, and a closing screw. The housing includes a cylinder bore, a recess, and a fluid channel. An end of the bore open to an outside of the housing has an internal thread. The recess is located in a region of the internal thread, and is deeper than a thread depth of the internal thread so that a floor region of the recess is free from thread turns. The piston is linearly moveable in the cylinder bore, and is configured to adjust a displacement volume of the machine. The screw is screwed into the internal thread so as to form a closed chamber between the piston and the screw. The fluid channel opens into the floor region of the recess, and is fluidically connected to the cylinder chamber.

Abstract: A pneumatic cylinder having internal hydraulic dampening device for cushioning the motion of a pneumatic piston (44) at its end of stroke. The hydraulic device includes a pair of hydraulic pistons (50, 52) cooperating with a pair of hydraulic cylinders to form a pair of hydraulic chambers (58, 64), which communicate with each other by a restricted flow passage (74). When the pneumatic piston nears its end of stroke, one of the hydraulic pistons is moved to compress the corresponding hydraulic chamber, forcing hydraulic fluid through the restricted flow passage, to the other hydraulic chamber. The flow of hydraulic fluid through the restricted flow passage slows the pneumatic piston, thereby cushioning the end of stroke motion. The restricted flow passage can include a plurality of flow passages which are sequentially closed by pins (136, 138, 140, 142) connected to one of the hydraulic pistons, as the hydraulic piston moves, to vary the restriction in the flow passage.

Abstract: A composite hydraulic cylinder apparatus which has a pneumatic cylinder mechanism, a braking oil hydraulic cylinder mechanism associated concentrically with the pneumatic cylinder mechanism, an oil passage for communicating between the front chamber and the rear chamber of the oil hydraulic cylinder mechanism, and a control valve provided in the oil passage for controlling the flow of the oil. Thus, the apparatus provides high positioning accuracy, a large holding force, economy and small size as a movable element control system, and can be applied as a buffer for the movable element.

Abstract: A cushioning mechanism in a pneumatic cylinder utilizing a supplied air pressure, and a method of cushioning a piston in the pneumatic cylinder. Cushioning chambers are provided at opposite ends of a cylinder body of the pneumatic cylinder. Respective differential pressure valves and relief valves are provided between each of the cushioning chambers and an air supply. A cushioning member is disposed between each cushioning chamber and a cylinder bore. Air supplied under pressure from the air supply is stored in one of the cushioning chambers. When the piston is displaced to push the cushioning member, the air in the cushioning chamber is compressed to cushion the piston. As the cushioning member is moved a prescribed interval, the cushioning chamber is vented to atmosphere.

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 cylinder driving system comprising balance cylinders communicated to an accumlator for supporting a load under balanced state, a drive cylinder of a small diameter connected by way of a switching control device to an air source for driving the load with reduced air consumption and a speed controller provided either to the balance cylinders or to the drive cylinder for switching the load driving speed between high and low speeds.

Abstract: A pumping unit for removing oil or the like from a well. The unit comprises a tower, a sump at the bottom of the tower and a reservoir at an elevation above the sump. A liquid, such as oil or water, is pumped from the sump up to the reservoir. A wheel is mounted at the top of the tower above the reservoir for rotation, and a line extends over the wheel for attachment at one end to a polished rod load outside the tower and at its other end to a receptacle inside the tower serving as a counter weight for the polished rod load.