Did You Know...
...that one person who claimed to be the inventor of the television is Russian emigre Vladimir Zworykin? In 1929 David Sarnoff, founder of RCA, asked Zworykin what it would take to develop TV for commercial use. He said: a year and a half and $100,000. In reality, it took 20 years and $50 million! Before his death in 1982 at the age of 92, Zworykin said of his invention: "The technique is wonderful. It is beyond my expectations. But the programs! I would never let my children even come close to this thing."
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| Number | Title | Issue Date |
| 6030183 | Variable margin pressure control A variable margin pressure control for a variable displacement load sensing pump comprises a body having a bore therein and a valve spool slidably disposed in the bore defining a chamber in continuous communication with a discharge passage in the body. Th... | 02/29/2000 |
| 5927072 | Load sense hydraulic system A load sense hydraulic system includes a pilot operated on/off valve disposed within a signal line which communicates a dynamic load sense signal from a steering control valve to a pressure controller of a load sensing pump. Upon actuating a brake valve o... | 07/27/1999 |
| 5907991 | Quick drop valve control The present quick drop valve control provides both quick drop and float functions by moving a quick drop valve to a position interconnecting the drop and lift sides of a pair of lift cylinders when a directional control valve reaches a predefined position... | 06/01/1999 |
| 5876185 | Load sensing pump control for a variable displacement pump A variable displacement pump has a discharge passage and a displacement controller disposed to decrease pump displacement in response to an increasing pressure signal and to increase pump displacement in response to a decreasing pressure signal. A load se... | 03/02/1999 |
| 5875631 | Control system for a hydrostatic transmission A hydrostatic transmission has a pair of overcenter variable displacement pumps, each having a flow control element controlled by a double acting actuator to control direction and flow rate of the pump. Fluid pressure in first and second chambers of each ... | 03/02/1999 |
| 5800130 | Pressure control system for a variable displacement hydraulic pump A displacement control valve includes a valve element having a first operative position communicating a displacement controller of a variable displacement hydraulic pump with a tank for increasing the pump displacement and a second operative position comm... | 09/01/1998 |
| 5709368 | Hydraulic control valve for fluid metering and cylinder protection A hydraulic control valve for minimizing fluid leakage from a load actuating cylinder and for protecting the cylinder from damage has a composite valve body with a poppet slidably disposed in a bore and biased to the closed position. A pilot spool, contro... | 01/20/1998 |
| 5682955 | Blade control system for an earthmoving blade A blade control system includes a directional control valve, a fluid regeneration valve and a selector valve for selectively controlling fluid flow between a pump and first and second hydraulic cylinders and between the cylinders. With the valves position... | 11/04/1997 |
| 5673606 | Swash plate actuating device for axial piston pumps and motors A swash plate actuating device for an axial piston unit has a swash plate tiltably mounted within the housing. A pair of axially aligned actuating chambers defined in the housing slidably receive the opposite ends of an elongate actuator and are disposed ... | 10/07/1997 |
| 5666807 | Oil processor circuit Oil coolers are commonly used in hydraulic systems for maintaining oil below a preselected temperature under normal operating conditions. The subject oil cooler circuit includes a pilot operated valve disposed in a conduit connecting the hydraulic system ... | 09/16/1997 |
| 5645263 | Pilot valve for a flow amplyifying poppet valve A flow amplifying poppet valve has a main poppet for controlling fluid flow from an inlet port to an outlet port of a main fluid passage. The position of the main poppet is controlled by controlling the pressure in a first control chamber adjacent the mai... | 07/08/1997 |
| 5626070 | Control logic for a multiple use hydraulic system A control logic for a multiple use hydraulic system includes a selector switch having a first position connecting a battery to a treadle switch operable to energize a solenoid pilot valve for communicating pilot fluid to an end of a first directional cont... | 05/06/1997 |
| 5611199 | Two stage electrohydraulic pressure control valve A two-stage electrohydraulic pressure control valve modulatably controls engagement of a spring applied, pressure released brake when electrical power directed thereto is suddenly lost. The control valve includes a shutdown valve mechanism between a pilot... | 03/18/1997 |
| 5593285 | Hydraulic axial piston unit with multiple valve plates An axial piston hydraulic unit has a valve plate assembly positioned between a head and a rotatable cylinder barrel. The assembly includes a pair of valve plates stacked together to function as a single valve plate. The valve plate assembly defines a rest... | 01/14/1997 |
| 5581881 | Method of making a cylinder barrel having ceramic bore liners A cylinder barrel includes a casting having a plurality of ceramic bore liners cast in situ within the casting. The cylinder barrel is made by positioning the ceramic bore liners at predetermined locations within a casting mold and pouring a molten ferrou... | 12/10/1996 |
| 5568759 | Hydraulic circuit having dual electrohydraulic control valves A three position four way directional control valve having a single spool is typically used for controlling fluid flow from a pump to a cylinder and from the motor to a tank. The present invention includes a pair of electrohydraulic control valves with on... | 10/29/1996 |
| 5568762 | Stabilizing device for variable displacement axial piston pumps A piston for a variable displacement axial piston hydraulic pump has a vibration absorber disposed within a chamber of the piston. The vibration absorber includes a vibration absorber mass suspended between a pair of springs. The vibration absorber offset... | 10/29/1996 |
| 5567123 | Pump displacement control for a variable displacement pump A pump displacement control for a variable displacement pump includes a torque control valve disposed between a variable torque limiter and a force applying device disposed in axial alignment within a common bore. A sleeve and a valve spool are movable re... | 10/22/1996 |
| 5564905 | Displacement control for a variable displacement axial piston pump A variable displacement axial piston hydraulic unit includes a flat port plate disposed between a stationery head and a rotatable cylinder barrel. An arcuate actuator piston extends from the port plate and is slidably disposed within an arcuate pocket in ... | 10/15/1996 |
| 5562125 | Two stage electrohydraulic pressure control valve A two stage electrohydraulic pressure control valve includes a pilot stage for providing regulated pressure at lower flows to a larger main stage that handles the higher control flows to and from a pressure applied clutch or pressure released brake. The r... | 10/08/1996 |
| 5562424 | Pump displacement control for a variable displacement pump A pump displacement control for a variable displacement pump includes a torque control valve serially disposed between a remotely controllable displacement control valve and a variable torque limiter in axial alignment within a common bore. A displacement... | 10/08/1996 |
| 5554007 | Variable displacement axial piston hydraulic unit A variable displacement axial piston hydraulic unit includes first and second control pockets individually disposed between first and second arcuate shaped fluid passages, a first electrohydraulic valve for controlling fluid flow between the first control... | 09/10/1996 |
| 5546847 | Hydraulic cylinder snubbing arrangement A hydraulic cylinder snubbing arrangement includes a pilot operated control valve having a predetermined snubbing position at which flow exhausted from a hydraulic cylinder actuating chamber must pass through a plurality of flow restricting orifices in a ... | 08/20/1996 |
| 5540050 | Hydraulic system providing a positive actuator force Hydraulically actuated grapple tongs mounted to a log skidder are useful, for example, in gripping a bunch of logs that are being dragged from one site to another. Maintaining a grip on the logs during the dragging operation with known hydraulic systems g... | 07/30/1996 |
| 5528977 | Retention mechanism for a cage of a swashplate bearing A flexible retention mechanism for maintaining a positional relationship between a bearing cage of an arcuate roller bearing assembly and a swashplate supported by the bearing assembly includes a flexible retainer connected to the bearing cage and having ... | 06/25/1996 |
| 5520262 | Electrohydraulic steering system An electrohydraulic steering system has a three position pilot operated directional valve disposed between a variable displacement pump and a pair of steer cylinders. The directional valve controls the direction of fluid flow from the pump to the steer cy... | 05/28/1996 |
| 5515768 | Slipper holddown device for an axial piston pump An axial piston hydraulic device includes a holddown device for maintaining the slippers swivably connected to pistons in sliding contacting with a cam surface of a swashplate. The holddown device also includes a nested wave spring disposed to resiliently... | 05/14/1996 |
| 5513958 | Accumulator charging valve An accumulator charging valve has a first valve spool determining a cut-in pressure level at which fluid from a pump is directed to an accumulator and a second valve spool determining the cut-out pressure level at which fluid is no longer directed to the ... | 05/07/1996 |
| 5511457 | Steering control system for an autonomous machine A steering control system for an autonomous machine has a manual steering control valve for directing fluid from a pump to either a head end chamber or a rod end chamber of a hydraulic steering actuator. In one embodiment, an electrically actuated steerin... | 04/30/1996 |
| 5509513 | Bidirectional snubber for a hydraulic suspension cylinder An end-of-stroke bidirectional snubber for a suspension cylinder includes an elongate snubber element having a first flow regulating end portion co-acting with an annular edge for gradually restricting fluid flow from a head end chamber as the piston appr... | 04/23/1996 |
| 5497692 | Electrohydraulic steering system An electrohydraulic steering system has a pair of proportional valves for controlling displacement of a steering valve for normal steering functions. The proportional valves are selectively energized by a position sensor in response to rotation of a steer... | 03/12/1996 |
| 5493860 | Method for flushing a closed loop hydraulic system A method of flushing a closed loop hydraulic system utilizes a pair of adapters temporarily disposed between a drive motor and a pair of hoses during the flushing procedure. The adapters block communication between the hoses and the motor and cover the in... | 02/27/1996 |
| 5471837 | Hydraulic system using multiple substantially identical valve assemblies A hydraulic control system is designed to permit the use of a plurality of small substantially identical existing valve assemblies in place of a lesser number of larger valve assemblies. In one embodiment, a first pair of variable displacement load sensin... | 12/05/1995 |
| 5421545 | Poppet valve with force feedback control A force feedback popper valve has a valve element for controlling fluid flow from an inlet port to an outlet port. A meter-in orifice communicates pressurized fluid from the inlet port to a control chamber above the valve element. A pilot valve provides a... | 06/06/1995 |
| 5415076 | Hydraulic system having a combined meter-out and regeneration valve assembly Fluid regeneration circuits are useful for filling expanding sides of a hydraulic cylinder with fluid being exhausted from the other side. The currently available circuits pass the excess fluid not needed for filling the expanded side of the cylinder thro... | 05/16/1995 |
| 5413030 | Self-energizing snubber for a hydraulic motor Snubbers are useful in dampening inertia loads at the end of stroke movement of a hydraulic motor. The known snubbers usually restrict fluid flow therethrough in the non-snubbing mode thereby slowing the response of the motor in the opposite direction. Th... | 05/09/1995 |
| 5406878 | Swashplate actuating device for axial piston pumps and motors Transmitting actuating forces from an actuator to a swashplate of an axial piston unit through a pin extending from a lever of the swashplate induces torsional stresses in the lever. The present invention overcomes this problem by securing a lever to a sw... | 04/18/1995 |
| 5395519 | Filter device for a hydraulic system Filter devices are useful in hydraulic systems for removing contaminants or foreign particles from the oil in the hydraulic system. One of the problems encountered with such filters is that they are subjected to high pressure drops thereacross when the oi... | 03/07/1995 |
| 5390584 | Follow up mechanism for a swashplate bearing A follow up mechanism for maintaining a timed positional relationship between a bearing cage of an arcuate roller bearing assembly and a swashplate supported by the bearing assembly includes a flexural elastic link pivotally connected to the bearing cage ... | 02/21/1995 |
| 5383391 | Cradle bearing arrangement for axial piston hydraulic devices Arcuate bearings are useful, for example, in pivotally supporting a cradle swashplate of axial piston variable displacement hydraulic devices. The bearings of known hydraulic devices have either been a pair of laterally spaced roller bearings assembly or ... | 01/24/1995 |
