Class / Patent application number | Description | Number of patent applications / Date published |
060462000 | With externally operable multiwasy valve means directing flow to a stroke device | 17 |
20100058753 | VALVE ASSEMBLY FOR AN ACTUATING DEVICE - A valve assembly for controlling the flow of pressurized fluid supplied to an actuating cylinder having a piston driven by the pressurized fluid along a stroke path therewithin, the pressurized fluid being applied to alternative driving sides of the piston. The valve assembly comprises a first and a second valve pistons, which cooperate to block the supply of pressurized fluid to the current driving side of the piston when the piston reaches the end of its stroke path, thereby limiting the pressure of the pressurized fluid supplied to the driving side to a level reduced compared to a pressure level applied to drive said piston. If a leak occurs within the actuating cylinder at the end of the stroke path of the piston, it will be at the reduced pressurized fluid pressure. | 03-11-2010 |
20110056195 | INFINITELY-VARIABLE, HYDRO-MECHANICAL TRANSMISSION USING FIXED DISPLACEMENT PUMPS AND MOTORS - This invention consists of two or more fixed displacement hydraulic pump/motors mounted on a common input shaft hydraulically connected to two or more fixed hydraulic pump/motors mounted on a common output shaft. The relative displacements of the pump/motors are chosen such that by selectively activating the individual pump/motors, the transmission ratio can be changed in the case when the input devices and acting as pumps driving the output devices as motors (conversely when driving the vehicle in reverse). Further, a hydraulic accumulator and reservoir are attached in a manner that allows the pressurized fluid to augment the flow produce by the input pumps in order to increase the transmission ratio. Similarly, the transmission ratio can also be reduced by causing the input pumps to pump fluid into the accumulator at the same time they are pumping fluid through the output motors. The transmission also contains a single speed all mechanical by-pass for use when cruising and an input reduction gear to increase the torque and power capacity of the transmission. | 03-10-2011 |
20110289912 | ELECTRO-HYDRAULIC ACTUATOR - An electro-hydraulic actuator (EHA) includes a hydraulic circuit having a plurality of pressure compensated flow control valves for allowing a maximum flow rate through the fluid conduits regardless of the loads imparted on the actuator. In one embodiment of the EHA, a plurality of combination manual override/thermal expansion valves that simplify the manufacture of the EHA. | 12-01-2011 |
20120279212 | CONTROL ARRANGEMENT - A control arrangement for use in a hydraulic control system including a control valve having at least two movable elements. The control arrangement is configured to control the positions of the two movable elements such that fluid from a common fluid pressure source is applied to both of the control surfaces of an actuator to drive the actuator. In an embodiment, the control surfaces have different effective areas. | 11-08-2012 |
20130047598 | Hydraulic Control Device for Work Vehicle - A hydraulic control device for a work vehicle includes: a hydraulic pump that supplies pressure oil; an arm drive actuator that drives, with pressure oil supplied from the hydraulic pump, an arm attached to the work vehicle so as to swing the arm; a bucket drive actuator that drives, with pressure oil supplied from the hydraulic pump, a bucket attached to a front end of the arm, so as to swing the bucket; an arm drive pressure oil control valve that controls drive of the arm drive actuator by controlling pressure oil supplied from the hydraulic pump to the arm drive actuator; a bucket drive pressure oil control valve that controls drive of the bucket drive actuator by controlling pressure oil supplied from the hydraulic pump to the bucket drive actuator; an arm operation unit that controls the arm drive pressure oil control valve; a bucket operation unit that controls the bucket drive pressure oil control valve; an operating state detection unit that detects operating states of the arm drive actuator and the bucket drive actuator; and a flow control valve that restricts pressure oil to be supplied to the arm drive actuator as combined operation of the arm drive actuator and the bucket drive actuator is detected via the operating state detection unit. | 02-28-2013 |
20130152575 | HYDRAULIC DRIVING APPARATUS FOR WORKING MACHINE - Provided is a hydraulic driving apparatus for a working machine, preventing an excessive decrease in pressure on a meter-in side and moving a load at a stable speed in a lowering direction. The apparatus comprises: a hydraulic pump; a hydraulic actuator; a manipulation device; a working hydraulic circuit including a meter-in flow passage and a meter-out flow passage; a control valve for changing a state of supply of hydraulic fluid to drive the hydraulic actuator at a speed designated by the manipulation device; a meter-in flow adjuster and a meter-out flow adjuster adapted to adjust a meter-in flow rate and meter-in flow rate respectively to respective value corresponding to the speed designated by the manipulation device; and a relief valve. The meter-in and meter-out flow adjusters have respective flow adjustment characteristics such that the meter-in flow rate is greater than the meter-out flow rate. | 06-20-2013 |
20130167522 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE - A circuit for driving a hydraulic cylinder of a construction machine includes: a hydraulic pump; a tank; a control valve; a bottom side line; a rod side line; a quick return circuit having a branch line branched off from the bottom side line and led to the tank and a quick return valve which allows hydraulic fluid to be flowed through the branch line only when the control valve is switched to a contraction driving position; and a recycling circuit which supplies a part of return fluid discharged from a bottom side fluid chamber to a rod side fluid chamber of the hydraulic cylinder. The recycling circuit allows the hydraulic fluid to be flowed only from the bottom side fluid chamber into the rod side fluid chamber of the hydraulic cylinder only when the hydraulic cylinder is switched to the contraction driving position. | 07-04-2013 |
20130219877 | System and Method for Calibrating Hydraulic Valves - A system and method for calibrating an electronically actuatable hydraulic valve in a work machine may include at least one supply valve and at least one drain valve to be calibrated and a bypass valve in fluid communication with a pump and a fluid source. The at least one supply valve and the at least one drain valve may be calibrated by opening the at least one supply valve and the at least one drain valve, closing the bypass valve, setting the pump to a desired flow output, determining a first current command for the at least one supply valve corresponding to a first target pressure parameter and determining a second current command for the at least one drain valve corresponding to a second target pressure parameter. | 08-29-2013 |
20130312403 | HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE HAVING ELECTRONIC HYDRAULIC PUMP - The present disclosure relates to a hydraulic system for a construction machine having an electronic hydraulic pump, and more particularly, to a hydraulic system which temporarily drives the construction machine when an operation of an electronic control unit controlling an electronic hydraulic pump is abnormal, particularly, when the electronic control unit is not able to perform a control because an operative amount of a joystick input to the electronic control unit is not normally transmitted to the electronic control unit. | 11-28-2013 |
20140013737 | Hydraulic System - An hydraulic system for an autonomous multi-set pipeline isolation tool comprising an hydraulic piston; a pump for operating the pistons; an accumulator between each of the hydraulic pistons and the pump; and means for operating the pump. The system also comprises a manifold operable to control the flow of fluid in fluid pipelines to control the operation of the pistons which actuate gripping and sealing means of the autonomous multi-set pipeline isolation tool. The hydraulic system further comprises a controller comprising a number of operational modules which are positioned on a single printed circuit board. The advantage of this is that the size of the hydraulic system may be minimised thereby enabling use of the system within a pipeline having an inner diameter of the order of 0.15 m (6″) and upwards. The manifold of the hydraulic system is also provided with a triple fail safe redundancy mechanism. | 01-16-2014 |
20150300380 | LIFTING DEVICE - An electromagnetic switching valve, for which the maximum opening is set to be small, is disposed on piping between a lift cylinder and a hydraulic pump motor. A pilot check valve, for which the maximum opening is set to be larger than the electromagnetic switching valve, is disposed on piping, different from the piping, between the lift cylinder and the hydraulic pump motor. In addition, during lowering operations, first, the electromagnetic switching valve is opened, and then after the same is opened, the pilot check valve is opened after a prescribed time has passed. Thus, the shock generated when lowering an object to be raised/lowered is reduced and a fork is operated quickly. | 10-22-2015 |
060463000 | Sensor of external condition controls valve | 6 |
20100313556 | CONSTRUCTION EQUIPMENT HAVING ELECTRIC CONTROL LEVER - Construction equipment having an electric control lever is provided, which can intercept a control signal applied to a flow control valve when trouble occurs in the electric control lever or a control unit. The construction equipment includes an electric control lever outputting a manipulation signal in proportion to a manipulation amount, a manipulation locking lever outputting a manipulation signal for control in preference to the manipulation signal when an error occurs in the manipulation signal, an electronic flow control valve installed in a flow path between the hydraulic pump and the hydraulic actuator and shifted, by signal pressure input in proportion to the manipulation signal, to control a start, a stop, and a direction change of the hydraulic actuator, a control unit having an operation unit operating a control signal that corresponds to the manipulation signal, and a current driving unit controlling current so that a current value corresponding to the control signal can be applied to the electronic flow control valve, and a power control unit intercepting current applied from the current driving unit to the electronic flow control valve when the manipulation locking lever is manipulated in a state where trouble has occurred in the electric control lever or the control unit. | 12-16-2010 |
20130239560 | HYDRAULIC PUMP CONTROL SYSTEM FOR CONSTRUCTION MACHINERY - Disclosed is a hydraulic pump control system for minimising flow loss by optimally limiting the discharge flow volume of the hydraulic pump when an upper swivel body is made to swivel abruptly. The hydraulic pump control system according to the present invention comprises: a swivel motor which is connected to a hydraulic pump; a control spool for the swivel motor, which controls the hydraulic fluid supplied to the swivel motor during switch back by means of a control signal for a remote control valve; an orifice which is provided on the furthest downstream side of a centre bypass pathway; a regulator which controls the angle of inclination of the swash plate of the hydraulic pump; a swivel operation signal detection means which detects a swivel operation signal output from the remote control valve; an electronic proportional pressure reducing valve which outputs a secondary pressure proportional to the detection signal of the swivel operation signal detection means; and a shuttle valve of which the input sides are respectively coupled to the orifice and the electronic proportional pressure reducing valve, and the output side is coupled to the regulator. | 09-19-2013 |
20140245732 | Proportional directional control valve, and hydraulic circuit and hydropneumatic suspension system having such a valve - The invention relates to a proportional directional control valve for controlling a hydraulic consumer, having a housing with a pressure port, a tank port, and first and second working ports. A control element is movably mounted in the housing. A single actuator is provided for moving the control element, which, in dependence on its position relative to the housing, enables different flow paths between the ports. The control element, starting from a first switching position in which both working ports are connected to the tank port, is movable by the actuator via a second switching position that follows the first switching position, to a third switching position that follows the second switching position. It is possible, by moving the control element from the first switching position into the third switching position, to successively disconnect the two working ports from the tank port and connect them to the pressure port. | 09-04-2014 |
20140305117 | POWER CYLINDER AND CONSTRUCTION MACHINE OR LIFTING GEAR - The invention relates to a power cylinder comprising a piston-in-cylinder unit having at least one pressure connection, an integral valve arrangement for controlling the pressure volume flow from the pressure connection into the cylinder space and an integrated control and/or regulation unit for actuating the valve arrangement. | 10-16-2014 |
20150292184 | LIQUID-PRESSURE CONTROL DEVICE - A liquid-pressure control device includes a switching valve, a manipulation valve, a first back pressure output mechanism, and a second shuttle valve. When a manipulation lever is manipulated, the manipulation valve outputs a first output pressure corresponding to a manipulation amount of the manipulation lever. When a predetermined operation state is satisfied, the first back pressure output mechanism outputs a first back pressure. The first output pressure is input as a first pilot pressure to the switching valve, and the first back pressure is input as a second pilot pressure to the switching valve. The switching valve supplies a liquid pressure to a boom cylinder at a flow rate corresponding to a differential pressure between the first and second pilot pressures. | 10-15-2015 |
20150376870 | Hydraulic Apparatus Based on Confluence Control Mode - A hydraulic apparatus based on a confluence control mode includes a load sensing unit provided with first and second reversing valves, and a throttle governing unit provided with a fourth reversing valve. A confluence valve and a one-way valve, which communicate with the load sensing unit and the throttle governing unit, are arranged on a parallel oil path arranged in parallel with the fourth reversing valve. The confluence valve includes a confluence channel that controls opening and closing of the parallel oil path to shunt fluid of the throttle governing unit to the load sensing unit. A first pilot pressure acting on the first reversing valve and a second pilot pressure acting on the second reversing valve act on the confluence valve independently or simultaneously to change a position of the confluence channel, thus implementing reversing of the confluence valve. | 12-31-2015 |