Abstract: A high-pressure valve assembly is provided. The high-pressure aerator valve assembly includes an outer housing with front and back ends terminating a central passageway; a movable valve member having a one-piece unitary metal construction slidably engaged within the central passageway in the outer housing, the valve member having an enlarged head termination sealing the front end of the passageway. The assembly also includes a spring-loaded spring guide member also having a one-piece unitary metal construction which is fixed within the central passageway in the outer housing intermediate the front and back end and a wave spring having a predetermined spring constant for supplying spring tension to keep the moveable valve member sealed. Also included are operational sensors which include a linear shaft displacement counter for counting the number of times the valve member opens and closes; a vibration sensor, or accelerometer, for measuring vibration, a temperature sensor and/or an air pressure sensor.

Abstract: A sanitary high pressure valve assembly is provided. The valve assembly includes an inlet adaptor for admitting pressurized gas into a sanitary central passageway for release into a storage vessel containing granular material for the purpose of aiding flow of the granular material from the storage vessel. The valve assembly also includes an isolation chamber for housing serviceable parts that are isolated from the sanitary central passageway.

Abstract: A high-pressure valve assembly is provided. The high-pressure aerator valve assembly includes an outer housing with front and back ends terminating a central passageway; a movable valve member having a one-piece unitary metal construction slidably engaged within the central passageway in the outer housing, the valve member having an enlarged head termination sealing the front end of the passageway. The assembly also includes a spring-loaded spring guide member also having a one-piece unitary metal construction which is fixed within the central passageway in the outer housing intermediate the front and back end and a wave spring having a predetermined spring constant for supplying spring tension to keep the moveable valve member sealed. Also included are operational sensors which include a linear shaft displacement counter for counting the number of times the valve member opens and closes; a vibration sensor, or accelerometer, for measuring vibration, a temperature sensor and/or an air pressure sensor.

Abstract: A sanitary high pressure valve assembly is provided. The valve assembly includes an inlet adaptor for admitting pressurized gas into a sanitary central passageway for release into a storage vessel containing granular material for the purpose of aiding flow of the granular material from the storage vessel. The valve assembly also includes an isolation chamber for housing serviceable parts that are isolated from the sanitary central passageway.

Abstract: A sanitary high pressure valve assembly is provided. The valve assembly includes an inlet adaptor for admitting pressurized gas into a sanitary central passageway for release into a storage vessel containing granular material for the purpose of aiding flow of the granular material from the storage vessel. The valve assembly also includes an isolation chamber for housing serviceable parts that are isolated from the sanitary central passageway.

Abstract: A sanitary high pressure valve assembly is provided. The valve assembly includes an inlet adaptor for admitting pressurized gas into a sanitary central passageway for release into a storage vessel containing granular material for the purpose of aiding flow of the granular material from the storage vessel. The valve assembly also includes an isolation chamber for housing serviceable parts that are isolated from the sanitary central passageway.

Abstract: The invention relates to a device for correcting error in temperature readings caused by thermocouple-to-extension wire ambient temperature fluctuations. The device creates an isothermal mass which raises the temperature of terminals to higher than ambient temperature. The isothermal mass consists of a self heating thermistor surrounded by thermal conductive epoxy inside an isothermal mass which contains the terminals. The isothermal mass is enclosed within insulating discs using a closure casing to complete the assembly. Using these higher than ambient temperature terminals for the connection between a thermocouple and extension wires, any error due to ambient temperature fluctuations is minimized.

Abstract: A method and control system for an agricultural harvester having a frame and a cut crop receiving header coupled to a hydraulic cylinder. The header has a cutter pivotably mounted on its bottom. The header has a height relative to the frame that is adjusted by applying fluid under pressure to the cylinder. A first control valve is fluidly coupled to the cylinder and responsive to a first input signal for increasing fluid pressure in the cylinder to raise the header. A second control valve is fluidly coupled to the cylinder and responsive to a second input signal for reducing fluid pressure in the cylinder to lower the header. An electrical flex angle signal is produced, representing a flex angle between the bottom of the header and the cutter. A plurality of local maximum and minimum values of the flex angle signal are measured as the cutter passes over respective maxima and minima of a height of the ground relative to the frame. The local maximum and minimum values are identified and stored.

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. 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: Mass flow of a fluid flowing in a conduit is detected by mounting an active device in thermal contact with an external wall of the conduit, the active device being characterized by a positive temperature coefficient of resistance of at least 10%/.degree.C. for a range of temperatures, driving the active device to operate within the temperature range, and detecting mass flow based on the resistance of the active device. In another aspect, a passive temperature sensor is arranged to sense the temperature of the fluid at one position along the conduit, the passive temperature sensor being substantially non-self-heating, an active device is positioned to exchange heat at another position along the conduit, the conduit having a resistance dependent on temperature, and mass flow is detected based on signals from the active device and from the sensor.

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 safety circuit for a silicon controlled rectifier controller of the type wherein the current delivered to a load is determined by controlling the firing angle of the silicon controlled rectifiers. The safety circuit is capable of sensing a shorted condition in the silicon controlled rectifiers and automatically disconnecting the load from the AC mains in the event of such a short circuit condition. Load current is sampled at a time in the cycle where it is expected to be zero. If at the sampling time a non-zero condition is detected, a relay is made to operate to actuate a circuit breaker or to perform other desired functions.

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 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 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 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.