Abstract: A water turbine powered electrical generation system is disclosed. The generation system includes a water-driven turbine completely submerged below a flowing water source. The flowing water source rotates the turbine, which is coupled to an electrical generator. The electrical generator generates electrical power for distribution away from the electrical generation system. The electrical generation system may be located on a floating or submersible platform.

Abstract: A dual hydraulic oscillator for the reciprocating cutter of an agricultural machine is provided. The dual oscillator has two pistons reciprocating in opposite directions and a single pilot valve, with resynchronization performed twice per cycle of the oscillator. Also provided is a single or dual hydraulic oscillator comprising a cylinder having first and second opposed ends. A reversing pilot valve is provided for controlling flow of pressurized fluid to at least one of the first and second cylinder ends. The pilot valve includes first and second pilot passages for controlling the reversing operation of the pilot valve. A piston reciprocates between first and second positions in the cylinder. The piston has an inner bore. The bore has first and second circumferential logic grooves. An inner logic mechanism is slidably received in the bore.

Abstract: A method and apparatus for controlling an agricultural harvester having a cut crop receiving header coupled to a hydraulic cylinder. The header applies a force against the ground that is adjusted by applying pressure to the cylinder. Proportional raise and lower valves control the pressure in the cylinder. A pressure signal representing cylinder pressure is received. The difference between the measured pressure and the setpoint is used to compute input signals, which are transmitted to the valves. Cylinder pressure is maintained substantially at a setpoint, the setpoint being adjustable in response to varying terrain. The setpoint is set to a first value in falling terrain and a second value in rising terrain. At the top of a hill, the setpoint is reduced below the first value until ground contact is regained, and the pressure is recharged above the second value.

Abstract: A method and apparatus for controlling an agricultural harvester having a cut crop receiving header coupled to a hydraulic cylinder. The header applies a force against the ground that is adjusted by applying pressure to the cylinder. A first proportional valve is fluidly coupled to the cylinder, and responds to a first input signal by increasing pressure in the cylinder to a setpoint value, when the pressure is less than the setpoint. A second proportional valve is also fluidly coupled to the cylinder, and responds to a second input signal by reducing pressure in the cylinder to the setpoint pressure value, when the pressure is greater than the setpoint. A pressure signal representing cylinder pressure is received. The difference between the measured pressure and the setpoint is used to compute the first and second input signals, which are transmitted to the valves.

Abstract: A hydraulic control system in which the flow of hydraulic fluid to and from cylinders on either side of a piston is controlled by normally closed check valves that are opened whenever a control valve is not in its neutral state. Float check valves respectively in series with the check valves and the check valves are opened when the control valve is in a neutral state by pressure from one of the cylinders so as to permit the load to move freely in response to external forces applied to it. A normally closed check valve is provided in which load sense pressures drive it open and pressure from a cylinder is balanced out. A cross check valve is such that the ratio of the areas for driving it open to the area for keeping it shut are at least 35:1.

Abstract: A car-carrying trailer having hydraulic cylinders for moving ramps has a single movable manually activated control unit and a single transmission link coupled to the control for controlling substantially all of the cylinders within the trailer. Data is received from the control unit and processed to determine the position of the ramps within the trailer and to produce control signals. Hydraulic cylinders move the ramps in accordance with the control signals. Position sensors transmit feedback to the processor and permit automatic termination of movement of the ramps to prevent damage to the cars. A vehicle is loaded onto the trailer and ramps within the trailer are adjusted until optimum ramp positions are obtained. Further in accordance with the invention sequence number is associated with the optimum ramp positions and the ramp positions are saved in a memory. At a later time, when the vehicle is to be loaded again, a sequence of ramp positions may be accessed.

Abstract: Method for manufacturing a electrohydraulic valve, a solenoid operated valve assembly, formed of a ferromagnetic end stop section and body section, an orifice section and a sleeve section of low magnetically permeable material. The sleeve section has an inner chamber with a centrally disposed portion of reduced diameter. Each of the sections is completely finished before assembly so that no further finishing operations are required. Predetermined sections are selected and a valve assembly is assembled by threading one end of the sleeve section to the end stop section and the other end to the body section. The orifice section is threaded to the body section to form a completed valve assembly.

Abstract: A single stage solenoid operated valve assembly of the cartridge type having a reversing flow orifice assembly with a side port, bottom port and an orifice. A poppet is adapted to seat in and close the orifice for controlling fluid flow between the side and bottom ports. A transverse flow passage provides fluid communication between the side port and the orifice and a pair of longitudinal flow passages provide fluid communication between the bottom port and a chamber above the poppet. An axis normal to the longitudinal axis of both longitudinal flow passages is also normal to the axis of the transverse flow passage. In this way pressure over the poppet is provided when fluid pressure is applied to the bottom port and pressure under the poppet is provided when fluid pressure is applied to the side port.

Abstract: A proportional follower spool valve system having a main spool slidable between end chambers maintained at substantially return pressure. First fluid connections are controlled by the main spool and they are effective to control output fluid flow in accordance with the position of the main spool. A pilot spool is slidable within an inner passage of the main spool. A first and a second driving chamber is formed by the main spool each having a driving area substantially less than the largest cross-sectional solid area of the main spool. Second fluid connections are controlled by the pilot spool for admitting fluid under pressure (1) to the first chamber when the pilot spool moves in a first direction away from the first chamber and (2) to the second chamber when the pilot spool moves in a second direction away from the second chamber. Each of the first and second driving chambers are disposed between a respective end chamber and a passage for return pressure.

Abstract: A solenoid having a high degree of proportionality. A stationary pole is disposed within an electromagnetic coil and forms part of a flux path. An armature slides into and out of a bore of the pole and forms another part of the flux path. The armature has walls which define an axial recess formed in the armature face adjacent the pole. The armature walls have a cross-sectional thickness which decreases in a direction toward the bore. The walls of the pole bore have a cross-sectional thickness which decreases in a direction toward the armature. An air gap is formed between the decreasing thickness pole bore walls and armature walls which air gap remains substantially constant in the radial dimension as the armature slides.

Abstract: A solenoid operated valve assembly formed of a ferromagnetic end stop section and body section, an orifice section and a sleeve section of low magnetically permeable material. The sleeve section has an inner chamber with a centrally disposed portion of reduced diameter. Each of the sections is completely finished before assembly so that no further finishing operations are required. Predetermined sections are selected and a valve assembly is assembled by threading one end of the sleeve section to the end stop section and the other end to the body section. The orifice section is threaded to the body section to form a completed valve assembly.

Abstract: A reel speed valve assembly for controlling the speed of a combine reel including a double acting compensator valve, a proportional controller valve, a relief valve, a load sense valve, and a manually adjustable controller valve may be operated as either a closed or open center valve and may be located at any position in a stack with minimal adjustment to manufacturing procedures.

Abstract: A dashpot assembly has a movable cylindrical element mounted within a housing. The movable element has a chamber with a first opening for restricting flow of fluid into the chamber and a second opening for permitting rapid flow of fluid out of the chamber. An enlarged head is disposed inside the chamber and is coupled to a poppet with a spring coupled between the poppet and the movable element. When the poppet moves in a direction away from the movable element, the enlarged head closes the second opening and pulls the element. Fluid then flows into the chamber only through the restricted first opening, thereby damping the rate of movement of the poppet. When the poppet moves in a direction toward the movable element, the enlarged head opens the second opening and the spring is effective to move the element in the same direction; fluid flows unrestricted through the second opening, thereby permitting an undamped movement of the poppet.

Abstract: A closed center programmed valve system having a load sense fluid source for control of the raising and lowering of load means by a raise and a lower normally closed two stage valve assembly. Each of the second stages of the valve assemblies has a poppet with a parabolic contour which is dimensioned to provide substantially linear flow rate change for minimized shock when the respective valve is actuated to the valve closed state. The load sense for the load means is taken from the outlet of the raise second stage without the requirement of a separate actuated valve or land with a load sense signal being applied to the fluid source during the time the raise valve assembly is actuated to the valve open state.

Abstract: A dashpot assembly has a movable cylindrical element mounted within a housing. The movable element has a chamber with a first opening for restricting flow of fluid into the chamber and a second opening for permitting rapid flow of fluid out of the chamber. An enlarged head is disposed inside the chamber and is coupled to a poppet with a spring coupled between the poppet and the movable element. When the poppet moves in a direction away from the movable element, the enlarged head closes the second opening and pulls the element. Fluid then flows into the chamber only through the restricted first opening, thereby damping the rate of movement of the poppet. When the poppet moves in a direction toward the movable element, the enlarged head opens the second opening and the spring is effective to move the element in the same direction; fluid flows unrestricted through the second opening, thereby permitting an undamped movement of the poppet.

Abstract: A hydraulic oscillator in which a piston reciprocates between first and second positions in a cylinder. A reversing pilot valve controls fluid flow to ends of the cylinder and flow through first and second pilot passages control the reversing operation of the pilot valve. The cylinder has a pilot channel or groove coupled to a pilot supply line. The piston has (1) a first logic channel for fluidly coupling the pilot channel and first pilot passage as the piston approaches the second position and (2) a second logic channel for fluidly coupling the pilot channel and second pilot passage as the piston approaches the first position thereby to alternately reverse the pilot valve and produce the reciprocation of the piston.

Abstract: A programmed valve system for positioning control having a first two stage valve assembly operable for raising a load and a second two stage valve assembly for lowering the load. Each of the second stages has a poppet with a parabolic contour which is dimensioned with orifice parameters to provide substantially linear flow rate change for minimized shock when one of the second stage poppets closes and the other opens. In the raise assembly, the pilot stage outlet orifice has a cross-sectional area substantially larger than that of the inlet orifice so that the second stage poppet opens much more rapidly than the closing thereof thereby to minimize overshoot when the pilot stage is actuated to the open position.

Abstract: A closed center programmed valve system having a load sense fluid source for control of the raising and lowering of load means by a raise and a lower normally closed two stage valve assembly. Each of the second stages of the valve assemblies has a poppet with a parabolic control which is dimensioned to provide substantially linear flow rate change for minimized shock when the respective valve is actuated to the valve closed state. The load sense for the load means is taken from the outlet of the raise second stage without the requirement of a separate actuated valve or land with a load sense signal being applied to the fluid source during the time the raise valve assembly is actuated to the valve open state.

Abstract: A valve system for an unbalanced load having a first two stage valve assembly operable for raising the load and a second two stage valve assembly for lowering the load. Each of the second stages has a poppet with a parabolic contour which is dimensioned with orifice parameters to provide substantially linear flow rate change when the second stage poppet moves for substantially zero flow jerk. In addition, the raise valve assembly has a pilot line coupled directly to the load so that high pressure oil is instantly available to actuate the second stage poppet. The lower valve assembly has a dashpot to decrease the rate of opening of that second stage poppet.

Abstract: A feathering valve system for modulating the fluid inflow to a selected one of first and second chambers of a movable biased assembly. A controller is electrically coupled to a first and second solenoid operated pilot valve assemblies for selectively (1) maintaining the pilot valve assemblies in a valve closed state without bleed flow through the pilot orifices or (2) supplying a predetermined value electrical signal to either, but not both, of the valve assemblies for actuating one of the assemblies to an open position related to the value of the signal. Fluid under a substantially constant pilot pressure is applied under the poppets of both valve assemblies. Fluid flow is taken from above the poppet of an actuated valve assembly to a respective chamber whereby the movable assembly moves to a position which is a function of the actuating signal value.