Abstract: A hydraulic steering assist assembly is provided for a vehicle with a mechanical steering assembly operable by a user to steer the vehicle. The hydraulic steering assist assembly includes a hydraulic actuator adapted to be coupled to the mechanical steering assembly and has a first side and a second side. A bi-directional hydraulic pump is placed in fluid communication with the first side and the second side of the hydraulic actuator. The hydraulic steering assist assembly further includes a valve in fluid communication with the first side and the second side of the hydraulic actuator, and a control system for controlling the bi-directional hydraulic pump and the valve. The bi-directional hydraulic pump provides a pressurized fluid to the hydraulic actuator, which applies a force on the mechanical steering assembly to assist steering the vehicle. The valve can act as a steering damper.

Abstract: A steering control system includes a steering circuit, a primary control circuit and a redundant control circuit. The primary control circuit includes primary proportional control valves, and a primary pilot valve having a thermal bleed of pilot fluid to warm the primary pilot valve when not operating to control the steering circuit. The redundant control circuit includes secondary proportional control valves, and a pressure reducing valve having a thermal bleed orifice allowing fluid flow to warm the pressure reducing valve when not operating to control the steering circuit. The thermal bleeds may also flow past the proportional control valves to raise their temperatures. The circuits of the steering control system are contained in a single valve group housing.

Abstract: A fluid controller includes a first fluid meter defining a first plurality of volume chambers and a second fluid meter defining a second plurality of volume chambers. A selector assembly, disposed between the first fluid meter and the second fluid meter, includes a selector plate defining a bore and a selector valve disposed in the bore. The selector valve is adapted for rotational movement between a first position and a second position and includes a first face and an oppositely disposed second face. The selector valve defines a plurality of thru-passages that extend axially through the first and second faces and that is adapted to provide fluid communication between the first and second volume chambers in the first position. The selector valve defines a groove disposed on the second face. The groove recirculates fluid from the second plurality of volume chambers when the selector valve is in the second position.

Abstract: A personal care article (20) has a longitudinal-direction (22), a relatively shorter, lateral cross-direction (24), a first end-section (72), a second end-section (72a), and an intermediate-section (76) which is contiguous with and interposed between the first end-section (72) and the second end-section (72a). The article includes a liquid permeable topsheet layer (26), and a backsheet layer (28) which is operatively connected to the topsheet layer (26). The article has been folded about a first, supplemental-fold-region (64) and a second, supplemental-fold-region (66) to provide a preliminary-folded article (82). The preliminary-folded article has been operatively enclosed in a wrap member (98), and the preliminary-folded article and wrap member have been folded along a composite-fold-region (96a) to provide a composite-folded, wrapped-article (114).

Abstract: A hydraulic steering system (1) with a supply connection arrangement, having a high-pressure connection (P) and a low-pressure connection (T), and with a working connection arrangement (L, R), a directional valve (2) and a metering pump unit (3, 4) being arranged between the supply connection arrangement and the working connection arrangement, the metering pump arrangement having at least two hydraulically parallel-connected and mechanically parallel-operated metering pumps (3, 4) with a shut-off valve (6) in a hydraulic connection between the two metering pumps (3, 4), said shut-off valve (6) having a return spring (16) and a first control inlet (15) that is connected with the high-pressure connection (P).

Abstract: A hydraulic steering system for a tractor is provided which can be operated in a conventional steering mode or in a fast steering mode. In conventional steering mode, a conventional steering wheel and steering motor direct pressurized oil to the steerable wheels for selecting the turning direction, the turning angle, and the speed with which the turning angle is achieved. In fast steering mode, a fast-turning valve is controlled by the operator to direct oil directly to the steerable wheels, thereby by-passing the steering motor. The conventional steering wheel and steering motor continue however to control the steering operation.

Abstract: A method of controlling a power steering system having an adjusting mechanism for adjusting at least one vehicle wheel, a drive means to provide steering assistance, a steering wheel and a position sensor, comprises the following steps: it is determined whether the adjusting mechanism is approaching an end position; if it is found that the adjusting mechanism is approaching the end position, then the drive means is controlled in such a way that it provides a diminishing steering assistance.

Abstract: Hydraulic steering arrangement (15) with a steering handwheel (2), which is connected with a manual. pump (3), a pump (18) supplying hydraulic fluid, a steering motor (12) and a steering valve (15) arranged between pump (18) and steering motor (12) and having a valve element (20) steering the flow of hydraulic fluid between the pump (18) and the steering motor (12), the valve element (20) being displaceable by hydraulic pressures originating from the manual pump. In such a steering arrangement it is wanted to create the opportunity of implementing various functions, without having to abandon the ordinary hydraulic control. For this purpose, the valve element (20) has an additional drive (31).

Abstract: A hydraulic valve apparatus is for controlling pressurized fluid flow to at least a pair of coupled hydraulic actuators in response to operator signals. The valve apparatus comprises a main body having main ports communicating selectively with a fluid supply and fluid return, body ports to communicate with the actuators, and a scavenge port to communicate with the return. Each actuator communicates with two control valves and one scavenge valve on the valve body to control fluid flow relative to the actuators. Control devices cooperate with the control and scavenge valves of each actuator so as to actuate the respective valves simultaneously. The control devices maintain the two related control valves in the same phase with respect to each other, but in an opposite phase to the respective scavenge valve.

Abstract: A full hydraulic type steering control system is provided with a steering control valve for outputting a flow of a pressurized discharge fluid of a hydraulic pump in proportion to an amount of steering at a steering wheel, and a directional control valve for delivering the pressurized discharge fluid of the hydraulic pump into a steering control cylinder, with the output flow of pressurized fluid of the steering control valve being switched as a pilot fluid pressure. The directional control valve comprises a spool adapted to be slidably inserted in a spool bore of a valve body.

Abstract: 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 steering wheel. However, should an electrical malfunction occur, rotation of the steering wheel beyond the normal operating range causes a steering control member to mechanically move an armature of the proportional valves through a spring to provide mechanical/hydraulic steering. Making the armatures of the proportional valves responsive to a mechanical input through the springs provides a simple, cost effective mechanical/hydraulic backup for the primary electrohydraulic steering control.

Abstract: A lock valve apparatus and a hydraulic system incorporating a lock valve apparatus including a lock valve body with a bore, a first port, a second port, a third port and a fourth port. There is a spool valve with a valve spool reciprocatingly received in the bore. The spool valve, a first one-way valve and a second one-way valve normally prevent fluid flowing between the ports. The first one-way valve and passageways in the valve permit a fluid flow from the first port to the third port when the first port is pressurized. The second one-way valve and passageways in the spool valve body permit a fluid flow from the second port to the fourth port when the second port is pressurized. The spool valve is shifted to align passageways, including a first annular passageway, between the spool and the bore to permit a return flow of fluid from the fourth port to the second port when the first port is pressurized. The first annular passageway receives pressurized fluid from the fourth port.

Abstract: A fluid power apparatus is connected to a pressurized fluid supply and a conventional helm pump controlled by the helm of a vessel to shift the rudder. The apparatus comprises an actuator cylinder connectable to the rudder, and a servo cylinder and a main valve connected to the helm pump to pass fluid therebetween and between the actuator cylinder. The actuator cylinder and servo cylinder have respective bodies and piston rods, and portions of the servo cylinder and actuator cylinder are connected together for concurrent simultaneous movement along respective longitudinal axes. Valve shifting structure is responsive to a change in fluid signal from the helm pump applied to the servo apparatus. Fluid diverting structure is responsive to a threshold supply pressure so as to actuate the valve to stop flow of supply fluid when supply pressure drops below the threshold pressure.

Abstract: A power steering apparatus for a marine craft includes an actuator assembly including a hydraulic steering actuator. The steering actuator is operatively connected to the tiller of the craft. A hydraulic servo actuator is mounted on the steering actuator. The servo actuator is permitted limited axial displacement relative to the steering actuator. The servo actuator is operatively connected to the steering actuator. A servo valve is mounted on the actuator assembly and has ports for receiving pressurized hydraulic fluid. The servo valve is hydraulically connected to the steering actuator. A member operatively connects the servo valve to the servo actuator. Displacement of the servo actuator opens the valve to provide pressurized hydraulic fluid to the steering actuator. The steering actuator includes a steering cylinder, a piston reciprocatingly received in the cylinder, a piston rod connected to the piston and end fittings on each end of the cylinder.

Abstract: Hydraulic steering arrangement, comprising a first hydraulic pump connected to a steering wheel, a piston cylinder device hydraulically coupled to the first hydraulic pump and arranged for connection to a steering mechanism, a second hydraulic pump and a second piston cylinder device hydraulically coupled via a servo valve to the second hydraulic pump. The second piston cylinder device is connected to the steering mechanism. The servo valve has an actuating element which is affected by the first piston cylinder device to activate the second piston cylinder device, and which comprises a tubular element limitedly displaceable relative to the servo valve housing. A guide (20) is axially displaceably mounted in the tubular element (13) and is joined to the piston cylinder devices (5, 17).

Abstract: A lock valve for marine hydraulic steering systems includes a valve body with a spool valve reciprocatingly received in a bore therein. A first port and a second port of the valve are connected to a manual pump. A third port and fourth port are connected to a double acting hydraulic cylinder connected to a rudder or steerable motor. There are valves within the lock valve which normally prevent fluid flowing between the ports so the steering system remains in a fixed position when the helm is released. Fluid can flow from the first port to the third port when the first port is pressurized. A return flow of fluid from the fourth port to the second port is permitted only when the first port is pressurized. When the second port is pressurized, fluid can flow the second port to the fourth port. A return flow of fluid from the third port to the first port is permitted only when the second port is pressurized.

Abstract: A fluid power apparatus is connected to a pressurized fluid supply and a conventional helm pump controlled by the helm of a vessel to shift the rudder. The apparatus comprises an actuator cylinder connectable to the rudder, and a servo cylinder and a main valve connected to the helm pump to pass fluid therebetween and between the actuator cylinder. The actuator cylinder and servo cylinder have respective bodies and piston rods, and portions of the servo cylinder and actuator cylinder are connected together for concurrent simultaneous movement along respective longitudinal axes. Valve shifting structure is responsive to a change in fluid signal from the helm pump applied to the servo apparatus. Fluid diverting structure is responsive to a threshold supply pressure so as to actuate the valve to stop flow of supply fluid when supply pressure drops below the threshold pressure.

Abstract: A hydrostatic power steering device is disclosed, which may be either a fluid controller (15) or a torque generator 111. The device is of the type including a housing (19;135) defining a fluid inlet port (29;113) and a return port (31;115). The device includes valve means (36;171) defining a neutral position and a first operating position. The device includes a gerotor mechanism (23;143) for imparting follow-up movement to the valve means in response to fluid flow through the gerotor, and a follow-up mechanism (49,51;183,185) transmits the follow-up movement to the valve means. The valve means defines a return fluid region (87,89,31g;205,197,157) which comprises part of the main fluid path. The return fluid region is isolated from the follow-up means and from the interior of the valving.

Abstract: A rear wheel steering hydraulic cylinder is arranged in a rear wheel steering apparatus to steer rear wheels to the right and left. When a front wheel steering angle detected by a front wheel steering angle sensor exceeds a predetermined value, the hydraulic cylinder is actuated to steer the rear wheels in a direction opposite to that of the front wheels. When the rear wheel steering angle detected by a rear wheel steering angle sensor is changed in response to the front wheel steering angle, the hydraulic cylinder is not activated, thereby not steering the rear wheels.

Abstract: In addition to a conventional steering system for steering a vehicle through the front wheels in accordance with an angular displacement of the steering wheel, the vehicle is equipped with a negative feedback steering control system which steers the vehicle through the front or rear wheels in accordance with an instantaneous yaw rate of the vehicle. The feedback system has a vehicle behavior sensor for sensing the yaw rate, and an control circuit which determines an actual quantity which is equal to the yaw rate or a linear combination of the yaw rate and the time derivative of the yaw rate and a reference quantity which is a function of the angular displacement and the vehicle speed, so designed as to be approximately equal to the yaw rate if there is no disturbance. The control circuit produces a feedback signal proportional to a difference between the actual quantity multiplied by a first coefficient and the reference quantity multipled by a second coefficient.

Abstract: A power steering system having a hydraulic motor driven by fluid flow from a hand operated pump and a main pump. The hand pump provides input to a control valve which amplifies fluid flow to the hydraulic motor, with fluid from the main pump, in proportion to the flow rate through the hand pump. The degree of amplification is controlled by ports within the control valve which also serve to communicate hand generated fluid pressure to the hydraulic motor. The hand pump will also allow delivery of hand generated fluid pressure to the hydraulic motor in the event of a main hydraulic pump failure.

Abstract: An improved fluid controller (17) is disclosed of the type for use in a load sensing hydrostatic steering system. The system includes a load sensing priority flow control valve (15) of the type which operates on a dynamic load signal. The controller includes a spool valve (95) and a sleeve valve (97) which cooperate to define a plurality of orifices including a main variable flow control orifice (71) and a variable orifice (75) through which fluid flows from the return side of a steering cylinder (19) to the return port (25) of the controller. A variable drain orifice (76) communicates between the main flow path, downstream of the main orifice (71) and the return port (25). As the controller valving moves from its neutral position toward an operating position, the orifice (75) begins to open at least as soon as the main orifice (71) and reaches a predetermined flow area before the main orifice (71) reaches that predetermined flow area.

Abstract: The invention relates to a steering control unit for a bidirectional servomotor which is connectable to steerable wheels. A steering wheel controlled quantity setting unit of a known type has ports connectable to a pump and a return tank and two control ports through which metered quantities of fluid flow to opposite sides of the servomotor and to other parts of the apparatus for actuating the servomotor. A directional control valve for selectivity directing pressurized fluid from a power circuit to opposite sides of the servomotor is controlled by a control circuit containing the setting unit. A utility valve having pressure regulating and control and power valve capabilities is provided. In cases wherein the quantity setting apparatus is remotely located from the regulating valve the length of the signal channels add to the reaction time.

Abstract: An improved hydraulic control valve is disclosed for providing the metering of fluid to a steering arrangement such as that normally employed on a motorized vehicle. The steering arrangement includes a piston-cylinder assembly, a main pump for supplying pressurized fluid from a fluid reservoir to the control valve and a control pump connected to the control valve which is actuated by a manually operated steering mechanism. The improved control valve includes a housing having an elongated bore formed therein. Movably positioned within the bore is a valve spool which has at least three annular grooves formed thereon separated by a pair of lands. The valve spool also contains a longitudinal bore formed therein which intersects a transverse bore which opens into the centrally positioned annular groove. The valve spool cooperates with the elongated bore to form control pressure chambers at each end thereof.

Abstract: A hydraulic power steering system has a steering valve which operates in accordance with steering input signals generated by a steering wheel operated metering pump and follow-up signals generated by a pair of follow-up cylinders to effect a desired turn. The steering valve acts in response to a relatively large signal, representing a desired sharp or full turn, to interrupt or block the follow-up signal whereby sharp turns may be accomplished without requiring as many turns of the steering wheel as would be necessary if follow-up flow were nullifying the input signal.

Abstract: A hydrostatic power steering control system with variable feedback compensation employing a unique compensating valve. The steering control system includes first and second hydraulic cylinders, each having two internal chambers denoted as head and feedback chambers. A piston is movably retained in each of the cylinders and is attached to a piston rod which extends outwards. The pair of piston rods are connected to a pair of steerable wheels by a mechanical linkage. Fluid contained in a reservoir is pressurized by a supply pump and is selectively passed to a head chamber of one of the cylinders by a control valve. The control valve is actuated by pressure differences in two interconnected fluid passages which connect to the feedback chambers of the two cylinders. A pressure difference in these passages is created by manually operating a steering wheel which actuates a metering pump positioned across the fluid passages.

Abstract: A hydrostatic power steering system with constant volume feedback compensation including first and second steering cylinders. Each cylinder has a housing containing a piston with an attached piston rod extending through one end of the housing. The pistons and piston rods form a head chamber and two feedback chambers within each of the cylinders. The outer ends of the piston rods are connected to a pair of steerable wheels and also to each other by a mechanical link which allows the piston rods to move simultaneously. A control valve is also present which selectively controls the passage of a pressurized fluid from a supply source to a head chamber of either of the cylinders. The cylinders, which have their feedback chambers fluidly connected together, are manually operated by a steering wheel which actuates a metering pump connected across the fluid passages.

Abstract: In a pressure compensated steering valve, the effect of an input steering signal is cancelled by connecting the spool valve actuator to the reservoir. A shiftable spool valve is acted upon by end cap actuators, which are in turn controlled by a hand pump that is operated by a steering wheel. The spool valve is provided with internal passageways which place the pressurized end cap actuator in restricted fluid communication with the reservoir in order to cancel the effect of the input steering signal at a predetermined rate.

Abstract: A steering control with a hydraulic follow-up wherein a movable valve member of a control valve is automatically brought back to a nonsteering disposition as a result of the movement of the device being steered to the desired steering position. Movement of the device is effected by a pair of steering cylinders. Control of the movable valve member is effected by a variable volume storage device which receives hydraulic fluid from the control valve and returns the fluid to the control valve as a function of the relationship of the steering mechanism and device to be steered.

Abstract: The invention relates to a hydraulic control unit for a servomotor of the type used for vehicle steering systems. The unit has a control circuit with a power operated pump and a hand operated metering motor and an operating circuit with a power operated pump. The two circuits intersect upstream from the servomotor. A pressure comparison, throttling and proportioning valve is disposed between the outlets of the two pumps of the control and operating circuits. The proportioning valve is controlled by a differential pressure applied by the pumps and a spring which supplements the operating pump pressure. In the normal operating mode the proportioning valve allows a minor fractional flow of the pressurized fluid generated by the control pump to flow through the valve to the operating circuit.

Abstract: An hydraulic reservoir for a dual circuit braking system of the kind comprising a container divided into two chambers by a partition provided with a hole at an intermediate height, and a fluid level sensor located in one chamber, in which the chambers are sealed from each other in use apart from the hole in the partition, and one of the chambers is sealed against atmosphere by sealing means which can be released to allow leveling of the fluid during filling.

Abstract: Dual double acting servomotors hydraulically pressurized are provided wherein the pistons have shunt valve means actuatable at limit of movement of the pistons to shunt high pressure fluid at one side of the piston to the low pressure side of the piston then being exhausted. This results in relieving the stress otherwise effected against steering mechanism limit stops by continued application of high pressure feed to the pressurized chamber. The system encompasses steering control and shunt circuit valve means automatically actuated by differential pressures so as to direct pressure and exhaust flow selectively to and from the chambers of the respective cylinders from an engine driven pump and a manual metering pump for operating the steered wheels of heavy duty vehicles and which valve means effects bypassing of the engine driven pump pressure feed directly to one servomotor while feeding the combined pressures of that pump and the metering pump to the other.

Abstract: A hydraulic control circuit for the steering system of an articulated vehicle is provided having a first pump means for delivering fluid under pressure and directional control valve means in fluid communication with the first pump means for controlling the direction of flow of the pressurized fluid. A second pump means, responsive to a steering input signal, develops an output indicative of a desired change in vehicle direction. An actuator means is connected to the directional control valve means for controlling the position of the directional control valve means, and said actuator means is in fluid communication with the second pump means so as to receive the output therefrom. A feedback means is placed in fluid communication with the actuator means for developing a feedback signal to counteract the effect of the second pump output, and a means is placed in fluid communication with the feedback means for varying the feedback signal to thereby vary the rate of counteracting the second pump output.

Abstract: A hydrostatic servomechanism adapted for controlling the direction of vehicles and selfpropelled machines. The servomechanism has a power circuit including a servopump, a distributor with reset mechanism, and a servomotor and a control circuit with a measuring pump connected through the control branches to the reset mechanism of the distributor and actuated by means of a command element, for example a vehicle steering wheel. The invention provides a simple reliable servomechanism with an artificial feedback simulator, non-sensitive to various harmful effects, providing a relatively stable and easily selectable gear ratio between the input and output parts of the servomechanism. The feedback simulator comprises a flow meter, a power circuit, and a controllable throttle means mechanically connected to the flow meter, the feedback simulator being incorporated between the control branches of the control circuit.

Abstract: A lock valve for marine hydraulic steering systems includes a valve body with a spool valve reciprocatingly received in a bore therein. A first port and a second port of the valve are connected to a manual pump. A third port and fourth port are connected to a double acting hydraulic cylinder connected to a rudder or steerable motor. There are valves within the lock valve which normally prevent fluid flowing between the ports so the steering system remains in a fixed position when the helm is released. Fluid can flow from the first port to the third port when the first port is pressurized. A return flow of fluid from the fourth port to the second port is permitted only when the first port is pressurized. When the second port is pressurized, fluid can flow the second port to the fourth port. A return flow of fluid from the third port to the first port is permitted only when the second port is pressurized.