Abstract: A hydraulic valve having a hollow valve body configured with a supply port and a supply port. The hollow valve body has several different internal diameters. An elongate spool is reciprocally received in the body and has a large diameter annular spool ring oriented adjacent a sensing land inside the hollow body forming a gap with a sensing land to cause a pressure drop across the gap in response to a flow of fluid from the pressure port through the gap to the control port. A servomotor reciprocally drives the spool lengthwise of the valve body against a spring force. When flow of fluid occurs in response to servomotor movement of the spool, the pressure drop across the gap combined with the spring force determines a pressure balanced location to which the spool is moved.

Abstract: A sequentially operated hydraulic valve for regulating a hydraulic fluid pressure from a single pressurized hydraulic fluid source to two different regulated pressures controlled by a single linear spring and by varying the position of end of the spring relative to the other end of the spring.

Abstract: A hydraulic valve having a hollow valve body configured with a supply port and a supply port. The hollow valve body has several different internal diameters. An elongate spool is reciprocally received in the body and has a large diameter annular spool ring oriented adjacent a sensing land inside the hollow body forming a gap with a sensing land to cause a pressure drop across the gap in response to a flow of fluid from the pressure port through the gap to the control port. A servomotor reciprocally drives the spool lengthwise of the valve body against a spring force. When flow of fluid occurs in response to servomotor movement of the spool, the pressure drop across the gap combined with the spring force determines a pressure balanced location to which the spool is moved.

Abstract: A steering system and method are described for a vehicle having steerable wheels, with steering of the wheels controlled, at least in part, by a valve assembly. A ground speed of the vehicle may be determined. Whether a steering command is being provided to a valve assembly may also be determined. An operational pressure at the valve assembly may be determined with a pressure sensor. A threshold pressure may be determined based upon the ground speed and/or whether a steering command is currently being provided. The operational pressure may then be compared with the operational pressure, and steering control with the valve assembly disabled based upon the comparison.

Abstract: A sequentially operated hydraulic valve for regulating a hydraulic fluid pressure from a single pressurized hydraulic fluid source to two different regulated pressures controlled by a single linear spring and by varying the position of end of the spring relative to the other end of the spring.

Abstract: A proportional pressure control valve which includes an electric first stage pilot having a single outlet port configured to provide a variable pressurized hydraulic fluid to the outlet port and at a pressure that is proportional to an electric input signal and which is variable between first and second values and further includes a second stage hydraulic valve which has a spool reciprocally moveable in a bore between first and second positions indicative of a full ON and a full OFF condition. A fluid isolation chamber is oriented in the bore and in a region between a control port and a tank port in the fluid pathway therebetween. The interior wall of the bore and the first and second diameter regions on the spool are configured to always provide a controlled volume fluid flow rate between the control port and the fluid isolation chamber.

Abstract: A pilot valve having a sleeve with a central hole therethrough and a first undercut region in an exterior surface thereof which includes a further passageway. A spool is reciprocally mounted in the further passageway for movement between first and second positions. A first end of the spool and a second undercut region thereon has a radially outwardly extending flange larger in diameter than a diameter of the central hole. A spring is provided for continually urging the flange toward a first position thereof in engagement with a first end of the sleeve to effect a closing off of the communication between the second undercut region and the passageway. A second end of the spool defines a nozzle orifice and opposes an end of the armature member configured to selectively move toward and away from the nozzle orifice to control a level of pressure at the control port.

Abstract: A pressure control valve having an electric first stage pilot with a single pilot outlet port and providing a variable pressurized hydraulic fluid to the pilot outlet port and at a pressure that is proportional to an electric input signal variable between first and second values. A second stage hydraulic valve is provided which has a valve body with a spool reciprocally movable in a bore. A first end of the bore is coupled to the aforesaid pilot outlet port. A spring abutment is provided in the bore at a second end remote from the first end, and a spring is oriented between and abuts the spring abutment and one end of the spool remote from the pilot outlet port for urging the spool to oppose the pressurized hydraulic fluid at the pilot outlet port.

Abstract: A gas flow control valve for quietly regulating the flow of a gas. The valve includes first and second coaxially oriented elongate tubes of magnetic material and an elongate sleeve of nonmagnetic material coaxially connecting the tubes. An electric coil assembly is disposed around the sleeve. A cover of magnetic material is provided around the coil and is in contact with the tubes. A nozzle opening is disposed within the first tube and has a valve seat encircling the nozzle opening. An elongate armature is axially slidably disposed within the sleeve and the first and second tubes and is moveable between first and second positions. The armature has a first end with an elastomeric seal member which abuts the valve seat when the armature is in the first position thereof to block the flow of gas. The armature further includes a gas flow passageway extending axially to a second end thereof. An elastically yieldable member is provided for continually urging the armature toward the first position thereof.

Abstract: Variable discharge and energy recovery is produced by an adjustable spool in fluid communication with the outlet chamber for adjustably providing pressurized fluid from the outlet chamber to selected portions of the demeshing area of the intermeshing teeth to vary the discharge flow of the pump and the amount of energy recovery. This results in maintaining a positive pressure in selected portions of the demeshing area as well as equalizing the pressure in the selected areas to the pressure in the outlet chamber. The adjustable spool also controls the connection between the inlet chamber and the demeshing area to vary the energy recovery.

Abstract: Variable discharge and energy recovery is produced by an adjustable spool in fluid communication with the outlet chamber for adjustably providing pressurized fluid from the outlet chamber to selected portions of the demeshing area of the intermeshing teeth to vary the discharge flow of the pump and the amount of energy recovery. This results in maintaining a positive pressure in selected portions of the demeshing area as well as equalizing the pressure in the selected areas to the pressure in the outlet chamber.

Abstract: A flow control and load check valve in a spool valve between a first power core (20) and the motor ports (22,24,26) for controlling the flow therebetween as a function of the differential pressure of the first power core and the inlet pressure. A piston (66) responsive to said two pressure positions a sleeve (76) to determine the flow rate. The sleeve (76) also serves as a load check.

Abstract: A hydraulic control system having a supply of low pressure hydraulic fluid and a hydraulic pump having a fluid inlet and a fluid outlet through which fluid is delivered at a high operating pressure when the pump is pumping at its capacity. A valve is placed in fluid communication with the supply of hydraulic fluid and the pump fluid inlet for permitting fluid communication between the supply of hydraulic fluid and the pump fluid inlet when in one mode of operation and for substantially preventing fluid communication between the supply of hydraulic fluid and the pump fluid when in a second mode of operation. A control means prevents the valve from assuming its second mode of operation until the magnitude of the pressure at the pump fluid outlet is below a predetermined pressure. The predetermined pressure is set to be substantially below the pump operating pressure.

Abstract: A mechanical detent for engaging a valve spool having a linear element wire spring positioned transverse to the valve spool for engaging circumferential grooves in the spool. The linear element spring includes a single wire spring having a triangular or square shape, or alternatively, one or more non-integral straight wire springs. Extensions of the linear element spring extend a distance away from the spool that is greater than the spring wire diameter. The extensions allow the spring to be movable out of the groove, while still permitting a small diameter spring wire.

Abstract: An improved control valve for double-acting piston and cylinder asemblies is disclosed in which pressure for actuating a regeneration valve to direct hydraulic fluid from the contracting side of the piston to the expanding side, is controlled by a cylindrical check valve apparatus (86-112) which surrounds the valve plunger and controls the pressure of fluid flowing from the contracting side to the reservoir.

Abstract: An improved gear pump or motor includes seal plates (30, 32) having a lubrication channel (48, 50) communicating between the shaft bearings (18, 20, 22, 24) and the low pressure side of the zone (62) where the gear teeth (58, 60) intermesh. Lubricant flow is directed first through one bearing on one side of the pump and then back through a separate channel (54, 56) to the other bearing on the same side of the pump. Placement of the lubrication channels on the low pressure side of the pump where the volume between intermeshing teeth is increasing and the pressure between the teeth is below inlet pressure ensures that flow reversals in the bearings and lubricant aeration are avoided; and renders bearing flow rate less sensitive to pressure, so that relatively large flow channels may be used in the wear plate.

Abstract: An electrical connector has a body of molded insulating material for fixedly holding a plurality of electrical conductors in the body. The connector body has openings with axial and radial passageways provided for axially or radially inserting or removing the conductors. A plurality of hinges are integral with the body and adjacent each opening for enlarging the adjacent opening in order to easily insert or remove conductors. The body is resiliently held in place by means of a seal disposed against an end wall of the body. Two or more elongated tabs are disposed opposite from one another and integral with an outer wall of the body for manipulating the outer wall to easily insert or remove the electrical connector from an electrical connector cavity.

Abstract: A system for providing auxiliary power comprises a primary circuit including a primary pump, an output line for providing primary power, and a return line. An auxiliary circuit includes an auxiliary pump, an output line for providing the auxiliary power and a return line. The auxiliary circuit also includes a valve for controlling fluid flow in the output and return line of the auxiliary circuit. A reservoir is connected to the primary return line and to the auxiliary return line. A controlled leakage apparatus for cooling the auxiliary pump is connected to the auxiliary circuit, the reservoir and the primary circuit, and in response to a predetermined output in the primary circuit directs a portion of auxiliary output fluid to the reservoir. Approximately all of the auxiliary output fluid is directed to the auxiliary output line when the primary circuit provides less than the predetermined output.

Abstract: A system for providing auxiliary power comprises a primary circuit including a primary pump, an output line for providing primary power, and a return line. An auxiliary circuit includes an auxiliary pump, an output line for providing the auxiliary power and a return line. The auxiliary circuit also includes a valve for controlling fluid flow in the output and return line of the auxiliary circuit. A reservoir is connected to the primary return line and to the auxiliary return line. A controlled leakage apparatus for cooling the auxiliary pump is connected to the auxiliary circuit, the reservoir and the primary circuit, and in response to a predetermined pressure in the primary circuit directs a portion of auxiliary output fluid to the reservoir. Approximately all of the auxiliary output fluid is directed to the auxiliary output line when the primary circuit provides less than the predetermined pressure.