Abstract: Provided is a driving apparatus capable of effectively preventing impact at the stroke end in the hydraulic cylinder. The driving apparatus includes a hydraulic pump, a cylinder control valve, an operation member, a drive command input unit inputting a cylinder drive command corresponding to a cylinder operation applied to the operation member to the cylinder control valve, a cylinder stroke detection unit, a cylinder drive command restriction unit restricting the cylinder drive command in response to the cylinder stroke to stop a piston of a hydraulic cylinder before the stroke end.

Abstract: A method for the supply of compressed air of a compressed-air consumer having two fluidically separate, kinematically coupled working areas, wherein each of the working areas is assigned to a valve arrangement which can be independently controlled and can be configured between a blocking position, a first functional position for a fluidically communicating connection to a fluid course and a second functional position for a fluidically communicating connection to a fluid sink and wherein each of the two valve arrangements is configured individually depending on a predefinable movement task for the compressed-air consumer and depending, on at least two pressure values from the following group: supply pressure, first working area pressure, second working area pressure, discharge pressure, for a provision of a predefinable developing for a fluid mass flow or for a provision of a predefinable developing for a fluid pressure in the respective working area or for a provision of a predefinable developing of a valve c

Abstract: A control device for a work machine on a construction vehicle is provided so that a bucket cylinder is stopped at a target position, with high accuracy achieved in a bucket cylinder length, and with chock held down to a low level. A bucket cylinder length detection section refereces a cylinder length detection table on the basis of a boom angle and a bell crank angle, thereby detecting a bucket cylinder length. A bucket attitude control section controls the bucket cylinder length so that a target position will be reached. Feedback control is performed until a set value which is set short of a target value is reached. After the bucket cylinder length reaches the set value, open loop control is performed until the target value is reached.

Abstract: According to one aspect of the invention, a fluidic actuator and a control system for the fluidic actuator may be provided. A first component of the actuator may have two openings interconnected by a passageway. A second component may be moveably housed within the passageway and divide the passageway into two portions. A fluid delivery system may be connected to the two openings. The fluid delivery system may supply a first pressure of fluid to the first portion of the passageway causing the second component to move within the passageway at a first speed. When the second component is in a selected position within the passageway, the fluid delivery system may reduce the pressure of the fluid, causing a reduction in speed of the second component. The fluidic actuator may be used in a wafer processing system.

Abstract: According to one aspect of the invention, a fluidic actuator and a control system for the fluidic actuator may be provided. A first component of the actuator may have two openings interconnected by a passageway. A second component may be moveably housed within the passageway and divide the passageway into two portions. A fluid delivery system may be connected to the two openings. The fluid delivery system may supply a first pressure of fluid to the first portion of the passageway causing the second component to move within the passageway at a first speed. When the second component is in a selected position within the passageway, the fluid delivery system may reduce the pressure of the fluid, causing a reduction in speed of the second component. The fluidic actuator may be used in a wafer processing system.

Abstract: The present invention relates to a method for attenuating the motion of hydraulic cylinders of mobile work machinery, in particular of hydraulic excavators, in which prior to the hydraulic cylinder reaching one of the limits of travel, its motion speed is reduced, and the hydraulic cylinder is moved to the respective limit of travel at reduced speed; wherein for the purpose of reducing the speed, the inflow to, and/or the outflow from, the hydraulic cylinder are/is throttled by a flow control device. According to the invention, the method is characterized by, prior to the respective limit of travel being reached, the motion speed of the hydraulic cylinder is registered, and the point in time when throttling commences is changed depending on the registered motion speed.

Abstract: A position control system is used for controlling a fluid operated cylinder having at least one fluid chamber defined by a piston located within a housing for movement between first and second end limits of travel. The system includes at least two electrically actuated proportional flow control valves connected to each port of the cylinder for selectively and proportionally controlling fluid flow into and out of the at least one chamber. At least one pressure sensor is provided for measuring fluid pressure with respect to each chamber. At least one discrete position sensor is located adjacent a midpoint of the cylinder for sensing a discrete centered position of the piston. A controller includes a program and is operably connected for controlling actuation of the at least two valves in response to pressure measured by the at least one pressure sensor and location measured by the at least one position sensor.

Abstract: A positioning system uses a position feedback signal to position and damp a platform. The position feedback signal is input to an electronic controller that provides a plurality of control signal that are used to position the platform and dampen the platform motion.

Abstract: A method of controlling a cylinder apparatus includes the steps of supplying compressed air of a first high pressure to one chamber of a cylinder which is divided into two chambers by a piston, and exhausting air from the other chamber so as to move the piston from the start position at an end portion of one chamber toward an end position at an end portion of the other chamber along the extending direction of the cylinder, and detecting if the position has passed the position of a sensor. In addition, a moving speed of the piston is decreased by supplying air of a second high pressure lower than the first high pressure to the other chamber after an elapse of a predetermined wait time from when the piston has passed the position of the sensor, so that the piston reaches the end position in a shock-free state.

Abstract: The invention relates to a hydraulic pressure booster which can be used to perform servo control of input and output at the preset servo ratio in, for example, a brake booster. In particular, the invention relates to a hydraulic pressure booster, which is designed to reduce the loss stroke of an input shaft in the initial stage of operation. This can be achieved by providing a stopper which directly abuts the input shaft when it is non-operational and which maintains the input shaft at the preset advance position separated from the detent in relation to the power piston.

Abstract: The invention relates to a method and a device for reducing the piston speed in a piston and cylinder assembly (1), as the piston approaches the end position. The piston end position is sensed, and a signal is generated for starting the end position dampening. Dampening is effected in two steps. In the first step (14), a time delay is provided and in the next step (15), the actual braking (retardation) of the piston is effected.The invention also comprises an electronic braking device comprising a dampening activation unit (13) which is connected to transducers (6), a braking delay unit (14) connected to the unit (13) and also to the control lever (5) at issue and a reference signal source, as well as a braking unit (15) connected to the delay unit (14) and adapted, upon activation, to provide a signal (U) to a setting system (3) for controlling the supply of pressure fluid to the piston and cylinder assembly (1).

Abstract: A hydraulic operating apparatus in which a differential piston is used as a drive unit, and in which the differential piston is driven by applying a high pressure fluid on a large piston face side through a hydraulic pressure control device for controlling the hydraulic pressure, and a high pressure fluid always being applied on the small piston face side. The hydraulic operating apparatus is constructed such that a high pressure fluid is applied concurrently on both piston faces when the differential piston stops at its receded position, and a thrust generated due to the difference between the forces applied on the both piston faces is held in check by a holding device acting on the differential piston or its extension. The differential piston is moved forward upon the removal of the holding force of the holding device, and the piston is moved backward upon the removal of the high pressure fluid on the large piston face side.

Abstract: The present system and apparatus for pumping an oil well damps out the stretch and over travel in sucker rod over travel particularly when the rod string approaches its point of reversal of direction either up or down. This is accomplished by decelerating the rate of travel of the rod string and at its end of travel pausing for a time period sufficient to allow rod string oscillations to damp out prior to reversal of rod string direction which due to the long length of the rod string, its weight and the weight of the trapped oil avoids breaking the rod string and the time loss occasioned thereby in both loss of well production and costly replacement of equipment and the time loss resulting therefrom.The present invention also achieves substantial recovery of hi-viscosity oil not recoverable at present by standard recovery procedures. This is accomplished with a sensor positioned to be actuated by the ram of the hydraulic drive.

Abstract: Automated control apparatus for an intermittently extended hydraulic cylinder is disclosed which governs cylinder elongation such that the rate of elongation is essentially constant with respect to time. The control apparatus includes a preset continuously variable timer that regulates the timer interval between sequential length increments of the cylinder. The control apparatus also includes a second timer which is responsive to the timer interval interposed by the first timer and which operates a valve controlling communication of hydraulic fluid between a hydraulic cylinder and a pump. The second timer may be discretely variable so that one of a plurality of predetermined length increments can be selected. Alternatively, the second timer may adjust the time period during which the valve is opened such that successive stages of a telescopic hydraulic cylinder have equal length increments.

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.