Did You Know...
...that power steering was invented by independent inventor Francis W. Davis? As chief engineer in the 1920s of the truck division of the Pierce Arrow Motor Car Company, he saw how hard it was to steer heavy vehicles. So that he would be able to keep the profits from his future invention, Davis left his job, rented a small engineering shop in Waltham, Mass., and developed a hydraulic power steering system that led to power steering.
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| Number | Title | Issue Date |
| 8356479 | Hydrostatic travel drive having two hydraulic motors The invention relates to a hydrostatic drive having one hydraulic pump unit (3) and at least one first hydraulic motor unit (14) and a second hydraulic motor unit (15). The first hydraulic motor unit (14) and the second hydraulic motor un... | 01/22/2013 |
| 8347621 | Method of operating a fluid-working machine and a fluid-working machine The present invention provides a method of controlling a fluid working machine (12) having a plurality of working cylinders (14) having pistons (16) therein and arranged to drive a shaft (18), in which said cylinders are supplied with pre... | 01/08/2013 |
| 7921642 | Inertial body drive system A pressure selector valve (13) is provided between a hydraulic motor (1) and a directional control valve (5) to connect one of the main conduits (4A), (4B) on a high pressure side to a high pressure conduit (14) while connec... | 04/12/2011 |
| 7913491 | Hydraulic flow control system and method Apparatus and methods are provided for controlling a double-acting hydraulic cylinder during a load-induced rod-extending operation. The apparatus includes a activation circuit and valve for providing a flow path from a pump to the cylinder head end; a flow regenera... | 03/29/2011 |
| 7900446 | Hydrostatic drive with rotational speed limitation The invention related to a hydrostatic drive comprising a hydraulic pump (3) which is driven by a drive machine (2) and pumps into at least one first working line (4), and a pressure line (18) in which a feed quantity dependent on the spe... | 03/08/2011 |
| 7818968 | Hydraulic control device of construction machine A hydraulic control device of construction machine is provided with a control valve lying between a hydraulic pump and a hydraulic actuator for opening and closing a meter-in control flow path, and a flow rate control valve lying between a pump discharge line on the... | 10/26/2010 |
| 7818967 | Method for controlling a crane actuator The invention relates to a method and an apparatus for controlling an actuator (7, 8) of a crane by control means (10) in a situation where the lifting power of the actuator (7, 8) of the crane is increased temporarily by an auxiliary valve arra... | 10/26/2010 |
| 7640735 | Auxiliary pump for hydrostatic transmission An auxiliary pump assembly for a hydrostatic transmission that operates at a reduced pressure when the auxiliary circuit is not in use, and operates at an increased pressure when the auxiliary circuit is in use, thereby reducing the heat generated by the auxiliary p... | 01/05/2010 |
| 7594396 | Hydraulic controller for working machine A hydraulic controller for working machine according to the present invention, which presupposes an electronic control system where an integrated bleed-off valve common to hydraulic actuators is used for bleed-off control and the bleed-off valve is controlled by the... | 09/29/2009 |
| 7530226 | Access method and apparatus that limit motion according to load and position A hydraulic drive system for an access apparatus and a method of access is presented. The hydraulic drive system may include a hydraulic power unit, a hydraulic cylinder and a subsystem for limiting motion of the access system according to the position of and/or loa... | 05/12/2009 |
| 7523610 | Neutral valve structure There is provided a neutral valve structure applied to at least one of a pair of operation fluid lines in an HST, including: a valve body slidable in the axis line direction so as to take a closing position where the corresponding operation fluid line is liquid-tigh... | 04/28/2009 |
| 7513111 | Shock valve for hydraulic device A shock valve assembly for a hydraulic system includes a fluid path extending between a first port and a second port with a shock valve disposed in the fluid path to normally block fluid flow through the fluid path between the first and second ports. The shock valve... | 04/07/2009 |
| 7469537 | Hydraulic transaxle and hydraulically driven vehicle A hydraulic transaxle comprises: an axle; a hydraulic pump driven by a prime mover; a hydraulic motor fluidly connected to the hydraulic pump so as to drive the axle; a bypass fluid circuit bypassing between suction and delivery ports of the hydraulic motor; a bypas... | 12/30/2008 |
| 7454905 | Clutch mechanism of hydrostatic continuously variable transmission A clutch mechanism for a hydrostatic continuously variable transmission has a hydraulic circuit including a high pressure oil path for feeding working oil from a hydraulic pump to a hydraulic motor and a low pressure oil path for feeding working oil from the hydraul... | 11/25/2008 |
| 7430861 | Shift controlled bypass orifice for hydrostatic transmission A shift controlled bypass orifice for a hydrostatic transmission includes a pump valve body with high pressure ports through which hydraulic fluid flows between a pump and a motor, a bypass orifice extending between the high pressure ports and the outside of the pum... | 10/07/2008 |
| 7373222 | Decentralized energy demand management A decentralized load management and control system and method are provided herein. A plurality of loads in a system are associated with a multitude of respective networked load controllers. If energy demand exceeds optimum limits in operation then the networked load... | 05/13/2008 |
| 7367371 | Inflation circuit, in particular for a tire mounted on a wheel, and corresponding wheel An automatic inflation and deflation circuit for a tube (3) is produced with a single compressed fluid supply conduit (5). The inflation results from subjecting a non-return valve (VA) in series on the conduit to excess pressure. Deflation is provided ... | 05/06/2008 |
| 7363759 | Hydraulic transaxle apparatus for a four-wheel-drive vehicle and four-wheel-drive vehicle using the apparatus An articulated vehicle with a working device has a first frame having a prime mover mounted thereon and supporting a first transaxle apparatus. The first transaxle apparatus includes an input shaft receiving power from the prime mover, a pair of first axles, and a h... | 04/29/2008 |
| 7360358 | Bypass mechanism for a hydraulic drive apparatus A bypass mechanism for a hydraulic apparatus is provided, where a rotatable hydraulic component such as a motor cylinder block is disposed on a running surface and in fluid communication with a closed hydraulic circuit. The hydraulic component is drivingly engaged t... | 04/22/2008 |
| 7350616 | Power steering pump having electronic bypass control A power steering pump comprises a housing that includes a bore, a fluid discharge port that supplies pumped fluid into the bore, and a fluid bypass port for recycling excess fluid to the pumping elements. The pump outlet is at one end of the bore. A flow control val... | 04/01/2008 |
| 7337869 | Hydraulic hybrid vehicle with integrated hydraulic drive module and four-wheel-drive, and method of operation thereof A vehicle includes an integrated drive module coupled to an axle thereof. The module includes a hydraulic motor configured to provide motive power at an output shaft, and a differential for distributing the motive power to right and left portions of the axle. The hy... | 03/04/2008 |
| 7331175 | Hydraulic system having area controlled bypass The present disclosure is directed to a hydraulic system having a first source of pressurized fluid and at least one fluid actuator. The hydraulic system further includes a first valve disposed between the first source and the at least one fluid actuator. The first ... | 02/19/2008 |
| 7325398 | Closed circuit energy recovery system for a work implement A closed circuit hydraulic system includes a fluid reservoir, a hydraulic cylinder having a cylinder rod, a bidirectional variable displacement hydraulic pump that pumps fluid to either extend or retract the cylinder rod on demand, a flow control valve for relieving... | 02/05/2008 |
| 7322373 | High accuracy low leakage valve for high pressure applications A high pressure valve assembly (10) comprising a valve sleeve (14) and a valve body (16) slidably mounted in the valve sleeve (14) is disclosed, the valve body (16) and valve sleeve (14) each having first ends (18, 56... | 01/29/2008 |
| 7320577 | Dual pump transmission A dual pump apparatus for use on a vehicle or industrial application having a housing in which a pair of hydraulic pumps are mounted, having a cooling fan mounted on the primary or secondary input shaft on the opposite side of the pulley used to engage the prime mov... | 01/22/2008 |
| 7320217 | Load controller for hydrostatic transmission in work vehicles Disclosed is a load controller for use in a hydrostatic transmission for a work vehicle. Power supplied from an engine is branched to drive an implement system and a traveling system. The hydrostatic transmission connects, in an oil-hydraulic closed circuit, an oil-... | 01/22/2008 |
| 7320272 | Hydraulic system The present application relates to a hydraulic system having a hydraulic supply, a consumer and having a control valve, which is in communication with the consumer by means of a first line and a second line, it being possible for the control valve to be switched int... | 01/22/2008 |
| 7318386 | Power assist steering apparatus and method responsive to volume flow of fluid An apparatus and method for providing power assisted steering for a marine craft having a manually operable steering pump and a hydraulic steering actuator. A powered hydraulic pump is hydraulically connected between the manually operable pump and the actuator. Hydr... | 01/15/2008 |
| 7316114 | Valve for a hydraulic drive apparatus An improved valve for use in a hydrostatic drive apparatus for a vehicle such as a zero turn vehicle. For each hydraulic drive system in the vehicle, a valve is located between the high and low pressure sides of the closed hydraulic circuit connecting the hydraulic ... | 01/08/2008 |
| 7308789 | Hydraulic cylinder suspension method The present invention discloses a hydraulic cylinder suspension method for actively controlling shock-induced vibration when a hydraulic cylinder in a construction vehicle makes a sudden stop, the method comprising the steps of: determining whether the hydraulic cyl... | 12/18/2007 |
| 7305914 | Hydraulic actuator control valve An actuator includes a piston within a cylinder, the cylinder having a first fluid port in communication with an open side of the piston, and a second fluid port in communication with a shaft side of the piston. The piston travels in a first direction, toward the sh... | 12/11/2007 |
| 7302799 | Drive system for a vehicle The invention proposes a drive system for a vehicle, in particular for a tracked vehicle, having a drive machine and at least one load, which is mechanically coupled to an output drive of the drive machine, at least one control means being associated with the at lea... | 12/04/2007 |
| 7302798 | Hydraulic system, reservoir and pump suction enhancer for motor vehicle A hydraulic system for a motor vehicle is provided with a pump suction enhancer includes a body section defining a small chamber, a venturi tube passage exposed to the small chamber at an inner end thereof and connected to the suction port of the oil pump, and a noz... | 12/04/2007 |
| 7287375 | Hydraulic control device and industrial vehicle with hydraulic control device A main spool is located in a bypass line connecting a pump line to a return line. The main spool moves in an axial direction according to the pressure in a spring chamber and the pressure in a pilot chamber, thereby adjusting the opening degree of the bypass line. A... | 10/30/2007 |
| 7284563 | Surge relief apparatus and method A surge relief apparatus for sensing, tracking and responding to pressure changes in a flow system. The apparatus includes a fluid storage tank that is in fluid communication with the flow system. The apparatus also includes a control valve that is connected to the ... | 10/23/2007 |
| 7275371 | Bypass for a hydraulic device A bypass mechanism is provided for use in a hydrostatic transmission, to enable the user to open or close a valve between the two pressure sides of the hydraulic circuit of the transmission. An electrical mechanism is positioned to open or close the valve based on a... | 10/02/2007 |
| 7275368 | Fan revolution speed control method The invention is a fan revolution control method for controlling a pump-motor system, by controlling the fan revolution speed of a cooling fan adapted to be rotated by a fan motor to cool cooling target fluids. The pump-motor system drives the fan motor by a hydraul... | 10/02/2007 |
| 7263829 | Pump A hydraulic pump apparatus having an internal sump formed by a housing having an internal portion and an end cap secured to the housing. A rotatable cylinder block is located in the sump and driven by an input shaft extending into the housing. The pump apparatus als... | 09/04/2007 |
| 7251933 | Flow rate control device for power steering Provided are a hydraulic pump 7, an electromagnetic flow rate control valve 2 that controls the flow rate of hydraulic oil supplied from the hydraulic pump 7 to a power steering device PS, and a pressure compensating valve 4 that maintain... | 08/07/2007 |
| 7240486 | Electro-hydraulic system for fan driving and brake charging An electro-hydraulic system for a machine may include a brake charging system including at least one accumulator. A fan drive system may include a fan and a fan motor. A fluid source may be in communication with the brake charging system and the fan drive system. Th... | 07/10/2007 |
