Abstract: A hydraulic drive system for a spreader used to distribute a road surface treatment material, such as sand or salt, across a road surface. The hydraulic drive system enables the use of pressure-compensated proportional control valves in series relationship with the auger and spinner motors, by the provision of small restricted flow passages across the outlets of the valves.

Abstract: A hydraulic drive system for a spreader used to distribute a road surface treatment material, such as sand or salt, across a road surface. The hydraulic drive system enables the use of pressure-compensated proportional control valves in series relationship with the auger and spinner motors, by the provision of small restricted flow passages across the outlets of the valves.

Abstract: This invention generally concerns electronically controlled hydraulic valves for use in electro-hydraulically controlled transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator. The cage tank ports 52 return fluid from the valve 20 to a tank from where fluid circulates back to the pump. Main spool 112 controls fluid flow between cage clutch ports 54 and cage pump ports 56 or cage tank ports 52. An electro-magnetically operated pilot valve regulates fluid pressure applied to a control pressure surface 138. A feedback pressure passage 126, having feedback restriction orifice 128, restrains the rate fluid flows between the cage clutch ports 54 and the feedback pressure surface 114.

Abstract: The technical field of the invention generally concerns electronically controlled hydraulic valves adapted for use in electro-hydraulically controlled automotive transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and by cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator, such as that for an automotive clutch. The cage clutch ports 54 supply the fluid at a pressure that is proportional to an electrical control signal applied to a solenoid coil 252 of the valve 20. The cage tank ports 52 return fluid from the valve 20 to a tank from which the fluid circulates back to the pump. Located in the cage 42 is a main spool 112 that is movable laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the cage clutch ports 54 and either the cage pump ports 56 or the cage tank ports 52.

Abstract: This invention generally concerns electronically controlled hydraulic valves for use in electro-hydraulically controlled transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator. The cage tank ports 52 return fluid from the valve 20 to a tank from where fluid circulates back to the pump. Main spool 112 controls fluid flow between cage clutch ports 54 and cage pump ports 56 or cage tank ports 52. An electromagnetically operated pilot valve regulates fluid pressure applied to a control pressure surface 138. A feedback pressure passage 126, having a feedback restriction orifice 128, restrains the rate fluid flows between the cage clutch ports 54 and the feedback pressure surface 114.

Abstract: A control valve and a method of controlling fluid flow include an input device which provides an input for moving a primary valve member an amount which is a function of the input, thereby opening flow pathways through the valve. The control valve is connected to a mechanical feedback mechanism which moves a feedback valve member an amount which is a function of the movement of a device to which the fluid flow is directed, such as a hydraulic actuator. Movement of the actuator to a desired position causes the second valve member to be moved to such a position that, in combination with the first valve member, the flow pathways through the valve are closed. The actuator is thereby moved to and maintained at the desired position without the need for the electronics feedback sensor used in prior art systems to sense actuator position.

Abstract: A solenoid valve includes an armature having two permanent magnets axially spaced apart with a steel spacer therebetween. The permanent magnets act as magnetic flux diodes to reduce or prevent undesired forces on the armature due to parasitic magnetic flux. The magnets have stepped outer ends which, in conjunction with pole pieces having corresponding stepped pole piece ends, concentrate magnetic flux to increase the magnetic force on the armature.

Abstract: The technical field of the invention generally concerns electronically controlled hydraulic valves adapted for use in electro-hydraulically controlled automotive transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and by cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator, such as that for an automotive clutch. The cage clutch ports 54 supply the fluid at a pressure that is proportional to an electrical control signal applied to a solenoid coil 252 of the valve 20. The cage tank ports 52 return fluid from the valve 20 to a tank from which the fluid circulates back to the pump. Located in the cage 42 is a main spool 112 that is movable laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the cage clutch ports 54 and either the cage pump ports 56 or the cage tank ports 52.

Abstract: This invention generally concerns electronically controlled hydraulic valves for use in electro-hydraulically controlled transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator. The cage tank ports 52 return fluid from the valve 20 to a tank from where fluid circulates back to the pump. Main spool 112 controls fluid flow between cage clutch ports 54 and cage pump ports 56 or cage tank ports 52. An electro-magnetically operated pilot valve regulates fluid pressure applied to a control pressure surface 138. A feedback pressure passage 126, having a feedback restriction orifice 128, restrains the rate fluid flows between the cage clutch ports 54 and the feedback pressure surface 114.

Abstract: The technical field of the invention generally concerns electronically controlled hydraulic valves adapted for use in electro-hydraulically controlled automotive transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and by cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator, such as that for an automotive clutch. The cage clutch ports 54 supply the fluid at a pressure that is proportional to an electrical control signal applied to a solenoid coil 252 of the valve 20. The cage tank ports 52 return fluid from the valve 20 to a tank from which the fluid circulates back to the pump. Located in the cage 42 is a main spool 112 that is movable laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the cage clutch ports 54 and either the cage pump ports 56 or the cage tank ports 52.

Abstract: The technical field of the invention generally concerns electronically controlled hydraulic valves adapted for use in electro-hydraulically controlled automotive transmissions. The proportional pressure control valve 20 includes a hollow cage 42 pierced by cage tank ports 52, cage clutch ports 54, and by cage pump ports 56. The cage pump ports 56 receive fluid from a pump. The cage clutch ports 54 supply fluid to a hydraulic actuator, such as that for an automotive clutch. The cage clutch ports 54. supply the fluid at a pressure that is proportional to an electrical control signal applied to a solenoid coil 252 of the valve 20. The cage tank ports 52 return fluid from the valve 20 to a tank from which the fluid circulates back to the pump. Located in the cage 42 is a main spool 112 that is movable laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the cage clutch ports 54 and either the cage pump ports 56 or the cage tank ports 52.

Abstract: The technical field of the invention generally concerns electronically controlled valves for use in electro-hydraulically controlled transmissions. The valve 20 includes a hollow cage 42 pierced by tank ports 52, clutch ports 54, and by pump ports 56. The pump ports 56 receive fluid from a pump. The clutch ports 54 supply fluid to a hydraulic actuator. The cage clutch ports 54 supply fluid at a pressure that is proportional to an electrical control signal applied to a coil 252 of the valve 20. The tank ports 52 return fluid from the valve 20 to a tank. Located in the cage 42 is a main spool 112 that moves laterally relative to the cage 42 for controlling a flow of hydraulic fluid between the clutch ports 54 and either the pump ports 56 or the tank ports 52. An electro-magnetically operated pilot valve regulates a control pressure of fluid applied to a control pressure surface 138 at one end of the main spool 112.

Abstract: A control system for a mobile planting apparatus which permits discrete plant spacing to be determined and maintained independent of any wheel rotation on the planting apparatus or towing apparatus is disclosed, having: (1) a ground speed sensor wherein the rate of movement relative to the ground is determined independent of wheel rotation of the planting apparatus or towing apparatus; (2) an input/display device for inputting desired linear plant spacing; (3) a variable speed motor for mechanically driving seed metering devices on the planting apparatus at varying rates independent of any wheel rotation of the planting apparatus or towing apparatus, wherein the motor changes speeds in response to an electronic signal; (4) a programmable control circuit communicating electronically with the input/display device and ground speed sensor, wherein the programmable control circuit: (a) determines the number of seeds to be dispensed per linear unit of distance traveled based upon the desired spacing received from t

Abstract: An apparatus and method for detecting a leak in a closed, fluid transfer system, specifically a hydraulic system, by comparing the actual rate of fluid level change in the fluid reservoir to the rate of fluid level change computed from the rate of flow and capacity of the system wherein an actual rate of level change in excess of the computed change indicates leakage from the system. An apparatus for determining direction of flow through a conduit and method using the apparatus in which a magnet on a piston slidably engaged inside a valve body is caused to move thereby causing a variance in a measured inductance indicating the direction the piston has moved.

Abstract: An electrically controlled, proportional, pressure relief valve (100/200) used to control the maximum allowable pressure in a hydraulic line (3), whose pressure is used to control, for example, the relative up-and-down positioning and speed of movement of a combine header (1) on an agricultural combine, in which the effective maximum pressure of the pilot valve of the relief valve is controlled by a solenoid (113/213). The distal tip of the armature (114/214) of the solenoid bears against a movement and force translating drive pin (112/212), which in turn bears against a ball (110; FIG. 2) or a poppet pin (210; FIG. 3). The effective maximum pressure permitted by the relief valve is linearly varied by the applied voltage/current to the solenoid coil (115/215).

Abstract: A proportional fluid flow control hydraulic valve including a valve body in which a by-pass flow passage leads from an inlet port to a by-pass outlet port. A valve chamber is arranged between the inlet port and a regulated flow outlet port and the by-pass outlet port. The by-pass flow passage includes an annular auxiliary flow channel which extends in bypassing relationship around the valve chamber. A valve member movably mounted in the valve chamber has valve ports therein for controlling fluid flow from the inlet port and the auxiliary fluid flow channel past the valve member to the regulated flow passage. In one form, the valve member is normally disposed in balanced hydraulic equilibrium in the valve chamber to prevent fluid flow from the inlet port through the auxiliary fluid flow channel and the valve ports in the valve member into the valve chamber and thence into the regulated flow passage.