Abstract: A vehicle steering apparatus having a variable gear ratio unit arranged midway along a steering transmission system for connecting a steering wheel and a tire to change a transmission ratio upon driving a motor includes a connecting unit for stopping actuation of the variable gear ratio unit in accordance with an external signal to connect the input side of the variable gear ratio unit which is connected to the steering wheel to the output side of the variable gear ratio unit which is connected to the tire. Even if a reverse input acts from a tire side during traveling, the relationship between the steering amount of the steering wheel and the turning amount of the tire can be kept unchanged.

Abstract: In an electric power steering device, a rotating member is screwed onto a rack, which meshes with a pinion rotated by steering manipulation, via a screw mechanism. The rotation of a motor for generating steering assistance force is transmitted to the rotating member via a gear mechanism. The vehicle is turned by longitudinal movement of the rack caused by rotation of the pinion. The steering assistance force is applied in the longitudinal direction of the rack by driving the rotating member by means of the motor. The gear ratio of the gear mechanism is set such that the speed of rotation of the rotating member is equal to or greater than the speed of rotation of the motor.

Abstract: A housing assembly for an electrical device (such as an electronic circuit) is disclosed in which a support member is provided in a compartment to physically divide a componentry sensitive to such radiation. In a preferred embodiment, an electric power-assisted steering system is disclosed of the kind in which an electric motor (12) is connected through a gearbox to an output shaft operatively connected to a steering column of the vehicle and in which a one-piece housing (1) is provided which defines two discrete compartments (2, 3). A first compartment (3) is adapted to house the motor and the gearbox, and a second compartment (2) is adapted to house a motor control circuit and a motor drive circuit, a support member (21) being adapted to provide a physical banner between the two circuits. The one-piece housing (1) is advantageous in that it reduces the number of potential openings through which electromagnetic radiation may pass compared with providing multiple housings.

Abstract: A hydraulic power steering gear (10) for a vehicle comprises first and second valve members (40 and 42) which are disposed coaxial to one another and which are relatively rotatable about a first axis (38) to selectively port hydraulic fluid. The first valve member (40) has an associated axial bore (170). The axial bore (170) has a second axis (174) which extends parallel to the first axis (38). The second valve member (42) includes a cam surface (128). A plunger (200) is disposed in the axial bore (170) for movement along the second axis (174). The plunger has a detent surface (208). Springs (240) bias the plunger (200) axially toward the second valve member (42). A detent roller (220) acts between the first and second valve members (40 and 42). The detent roller (220) is located in the cam surface (128) and in the detent surface (208) in a neutral condition to provide a physically perceptible indication to a driver of the vehicle of operation between the neutral condition and an actuated condition.

Abstract: A rack guide (30) in a rack and pinion steering gear housing (12) comprises a cylindrical structure having a peripheral wall (42), an end wall (52), and an inner wall (71). The peripheral wall (42) has an outer surface (40) with a contour complementary to an inner surface (44) of the housing (12). The end wall (52) has a rack guide surface (54) configured to engage the rack (14) in line contact along a first straight line (57) parallel to the longitudinal axis (17) of the rack (14). The inner wall (71) has a linear configuration adjoining the end wall (52) along a second straight line (101) parallel to the first straight line (57).

Abstract: A position servo system exemplified by a power-assisted steering system in which a power-driven continuously-variable-ratio transmission ("CVT") of the variable-ratio-epicyclic type, and particularly of the toroidal-race rolling-traction type, is arranged coaxially with the wheel or other rotary actuating member and the steering or other driven mechanism, and delivers an output to augment the steering effort in response to an error between the positions of the actuating member and the steering mechanism. Mechanisms described to prevent interference with the normal manual connection between the actuating member and the steering mechanism should the CVT cease to rotate, and on occasions when the normal sense of operation is reverse and the steering mechanism tends to steer the actuating member. Mechanisms are also described, where the CVT is of the toroidal-race type, to ensure quality between the forces exerted on the steering mechanism by all its connections with the CVT.

Abstract: An electric power assisting steering apparatus comprises a housing, a motor mounted on the housing to generate auxiliary steering power in a rotating shaft, an output shaft to transmit the steering power for steering the wheels, a bearing for supporting the output shaft to be freely rotatable, and a worm gear mechanism having a worm connected to the rotating shaft and a worm wheel connected to the output shaft, to transmit the auxiliary steering power of the motor to the output shaft. An elastic body is provided between at least one of the rotating shaft and the housing and the bearing, so that when a tooth surface of the worm and that of the worm wheel are brought into contact with each other, the rotating shaft is moved in at least one of the axial direction and the radial direction relative to the housing by deforming the elastic body.

Abstract: A power rack and pinion steering gear (10) includes a rack (66), a pinion (54) meshing with the rack, and a power steering hydraulic motor (31) for moving the rack. The steering gear (10) includes first and second relatively rotatable valve members (40, 42) which control hydraulic fluid pressure in the hydraulic motor (31) and thereby control rack movement. A rotatable input shaft (50) is connected with the first valve part (40), the first valve part rotating upon rotation of the input shaft. A torsion bar (51) is connected between and acts between the input shaft (50) and the pinion (54). The steering gear (10) includes means, such as a rotatable fastener (56), for connecting the pinion (54) to the second valve (42) part to cause the pinion and the second valve part to rotate together. The fastener (56) is operable to rotate the second valve part (42) relative to the pinion (54) and the first valve part (40) while the torsion bar (51) is connected to the input shaft (50).

Abstract: An assembly for turning steerable wheels of a vehicle upon manual rotation of a steering wheel (12) includes a steering member (14) which is axially movable to effect turning movement of the steerable vehicle wheels. A housing surrounds at least a portion of the steering member (14). A ball nut drive (38) located within the housing is drivingly connected to a thread portion (26) of the steering member (14). An electric assist motor (36) located within the housing is drivingly connected to the ball nut drive (38). A fluid or lubricant (68) is located within the housing and damps movement of the steering member (14).

Abstract: A servo valve for a power assisted steering gear for producing an auxiliary steering force corresponding to twist between an input member and an output member which are connected to each other by a torsion bar is disclosed. There is provided a sleeve member surrounding a torsion bar and having first and second ends. The first end is prevented from being rotated with respect to the torsion bar. The second end is provided with an opening extending along the radius of the sleeve member. A plunger-containing hole extending in the radial direction is formed in an intermediate part between opposite ends of the torsion bar, and plungers are contained in the containing hole which are movable forward and backward. The plungers are urged forward by a helical compression spring interposed between the plungers. Each of the urged plungers is engaged with an edge of the opening serving as a holding arrangement, to increase the torsional rigidity of the torsion bar at the time when the valve is neutral.

Abstract: A rack-pinion type power steering apparatus includes a cylindrical stub shaft, a torsion bar, a pinion shaft, a rotor, and a sleeve. The stub shaft rotates in a steering body upon a steering operation. The torsion bar has one end fixed at one end of the stub shaft and extends through the stub shaft toward the other end of the stub shaft. The pinion shaft is pivotally connected to the other end of the torsion bar. The rotor is arranged to cover the torsion bar from the stub shaft along an extending direction of the torsion bar. The sleeve has one end integrally connected to the pinion shaft, extends from the pinion shaft along the stub shaft, and is arranged around the rotor to constitute a rotary type channel selector valve between the rotor and the sleeve. The pinion shaft is axially supported by the steering body at two end portions of the sleeve.

Abstract: In conventional power steering apparatus, a motor and a reducing device of this motor were set in a laterally projecting state with respect to the steering axis, which posed a problem of poor mountability. Harmonic drive reducer, which is composed of wave generator, flexspline, and circular spline, and print motor for driving it are coaxially arranged with respect to a serial steering axis connecting steering input shaft with steering output shaft.

Abstract: A centering compensator for resisting movement of the steerable wheels of a vehicle to either side of a selected center position, and for returning them to this center position after each such movement. The apparatus includes a cam follower member connected to the steerable wheels for movement therewith and arranged to engage the cam surface of a cam ring having one or more static rotational positions relative to its housing mounted on the vehicle frame. The cam surface has a centering depression and the follower member is carried by an arm member extending laterally from a centering shaft mounted for rotational movement relative to the cam ring. An actuator assembly applies a resilient biasing force to the follower arm for pressing the follower member into the centering depression in response to fluid pressure in a piston and cylinder assembly. The center position may be varied either locally or remotely by changing the static rotational position of the cam ring or the length of a centering shaft linkage.

Abstract: An electric power steering unit comprises a rack-shaft 2 to be coupled to the guiding wheels of a vehicle, a housing A for slidably containing the rack-shaft 2 and holding therein a coupling section 6 for causing the teeth of the rack-shaft 2 to engage those of a pinion arranged on the steering column 5 linked to the steering handle of the vehicle and an electric motor 1 coaxially arranged around the rack-shaft 2, which the rotary force is transmitted to the rack-shaft 2 by way of a ball screw mechanism 3 as the steering assisting power. A nut section 19 of the ball-screw mechanism 3 is rotatably supported by a housing B separately formed from the housing A, in a state of supporting the armature shaft 11 of the electric motor 1. The rack-shaft 2 is axially movable and supported by two points of support, one at the coupling section and the other at the nut section supported by the housing B.

Abstract: A torsion element (1) for a steering valve is provided. The torsion element (1) comprises a torsionally elastic rod member (2) having axially opposite first and second end areas (3, 4) which are rotatable relative to one another. The rod member (2) has a circumferentially spaced plurality of radially and axially extending indentations (10) adjacent the second end area. A generally tubular, torsionally stiff sleeve member (6) encircles the rod member (2) and is fixedly attached to the first end area (4) of the rod member. The sleeve member (6) includes a circumferentially spaced plurality of radially and axially extending grooves (9) which align with and radially overlie the plurality of indentations (10) in a neutral steering condition. The sleeve member (6) further includes a circumferentially spaced plurality of radial slots (7).

Abstract: A rack-and-pinion steering system has a rack which is toothed on two sides and cooperates with two pinions. At least one of the pinions can be axially translated in dependence on forces acting between the rack and that pinion. This axial translation controls a clutch arrangement so that a servomotor continuously rotating in one direction can in each case be nonpositively coupled to one of the pinions or uncoupled from both pinions.

Abstract: In a motor operated power steering device, a drive shaft accommodation hole in a housing communicates with a opening for fitting a steering assistance power generation motor. In the accommodation hole, a drive shaft, which is driven by the motor, is supported by rolling bearings at two separate points along the axial direction. A steering shaft is linked to a driven gear which meshes with a driving gear provided around the outer circumference of the drive shaft. Around the outer circumference of the drive shaft, there is a ring shaped preload applying member, the outer circumference of which has a male threaded section. The preload applying member is screwed into a female threaded hole, which is concentric with the accommodation hole, in between the motor and the rolling bearing closest to the motor, so that it is able to apply preload along the axial direction to both rolling bearings.

Abstract: A rack-and-pinion steering or control system with a servomotor, especially an electric motor, which can be coupled to the rack by way of a mechanical transmission and runs continuously in one direction is provided. The rack is designed over a certain area as a screw which interacts with a recirculating ball sleeve which can be driven in two directions of rotation by the motor. To control the direction of rotation, use is made of normally disengaged clutches which can be controlled as a function of a small displacement of the recirculating ball sleeve.

Abstract: A power steering gear including a spool shaft, a pinion head, a torsion bar between the spool shaft and the pinion head, and a rotary detent which resists twisting of the torsion bar including an annular first ball seat rotatable as a unit with a pinion head end of the torsion bar, an annular second ball seat facing the first ball seat, a plurality of detent notches in the first and second ball seats facing each other in pairs, a plurality of detent balls between the facing pairs of detent notches, a plain cylindrical sleeve around the torsion bar rigidly connected at a first end thereof to the second ball seat, a pair of radial abutments on the torsion bar near a spool shaft end thereof, and a pair of cantilever springs at a second end of the cylindrical sleeve having lateral deflection strokes perpendicular to a longitudinal centerline of the torsion bar and ramps which resiliently capture therebetween the radial abutments.

Abstract: An electrically operated power steering apparatus has a housing, a pinion rotatably supported in the housing, the pinion being adapted to be connected to a steering shaft, a rack shaft axially movably disposed in the housing and held in mesh with the pinion, an electric motor disposed coaxially around the rack in the housing, and a ball-and-nut mechanism disposed on the rack shaft in the housing for transmitting a torque produced by the electric motor as an axial displacement to the rack shaft. The electric motor has a stator fixedly mounted in the housing and a rotor rotatably supported in the housing by a pair of bearings mounted on respective opposite ends of the rotor, the ball-and-nut mechanism being coupled to the rotor. A rack guide is disposed in the housing behind the pinion remotely from the ball-and-nut mechanism and held in sliding contact with the rack shaft. The rack shaft is axially slidably supported in the housing by the ball-and-nut mechanism and the rack guide.

Abstract: An electric assist steering system (10) comprises a steering torque sensor (110) and an electric assist variable reluctance motor (26) operatively connected to a steering member (20). A motor control signal is provided in response to a value of the torque signal for control of the assist motor. A motor velocity sensor (200) senses velocity of the power assist motor and a vehicle speed sensor (119) senses the vehicle speed. A control circuit (220, 210, 142) modifies the motor control signal in response to the sensed motor velocity and the sensed vehicle speed signal so as to provide non-linear damping of the motor for vehicle yaw rate control.

Abstract: The present invention provides an electric power steering apparatus in which it is decided whether or not steering torque is in a predetermined drive inhibition area, and when the term in which the decision result is logically inconsistent with driving instruction for the motor in accordance with the steering torque is shorter than a predetermined period of time, a timer is reset to drive the motor. As a result, the compensation of the inertia of said motor can be controlled even when the steering torque is small. Further, in the electric power steering apparatus, the timer is also reset to drive the motor when the steering torque is in a dead zone and a driving current for the motor is smaller than a predetermined value. As a result, the drive of the motor can be controlled also when a steering wheel is returned to its initial position.

Abstract: In an auxiliary power steering intended especially for motor vehicles, a pinion (2) positioned in a steering housing (1) engages a steering rack (9). A steering valve (14) that is used to control the pressure medium for the auxiliary power steering provides two inlet-seat valves (15, 16) and two outlet-seat valves (17, 18) whose closing bodies (20, 21, 35, 36) can be shifted in the axial direction by a rotary movement of a steering spindle. Closing bodies (20, 21) of inlet-seat valves (15, 16) can be biased in the closing direction by the force of pressure springs (22, 23). In the process, pressure springs (22, 23) bias the closing bodies (20, 21) of inlet-seat valves (15, 16) only if the particular outlet-seat valves (17, 18) are in their neutral position. Each pressure spring (22, 23)--when steering valve (14) is in the neutral position--keeps closing body (20, 21) of the particular inlet-seat valve (15, 16) resting against a valve seat (26, 27) that is fixed on the housing.

Abstract: A power transmission device, having a frictional face and a pressure member pressed to the frictional face, is provided between the rotary shaft of a motor and a reducing mechanism of an electric power steering device, so that the power transmission is achieved utilizing a frictional force generated between the frictional face and the pressure member, before the output torque of the motor is amplified by the reducing mechanism. Consequently the power transmission device can be made simple and compact in configuration, as it is not necessary to increase the pressing force of the pressure member nor to increase the area of the frictional face.

Abstract: A torsion bar device includes a torsion bar having a torsional portion, an upper connecting portion associated with an input shaft, and a lower connecting portion associated with an output shaft; a first cylinder for encompassing the torsional portion, one end of the first cylinder being connected to one of the upper and lower connecting portions, and the other end of the first cylinder extending in the longitudinal direction of the torsion bar to the other connecting portion of the torsion bar; a second cylinder for encompassing and being connected to the other one of the upper and lower connecting portions of the torsion bar; a first supporting member for supporting the torsion bar at the other end of the first cylinder in a circumferential direction of the torsion bar; a second supporting member for supporting the torsion bar in the circumferential direction at a portion of the second cylinder where the second supporting member is aligned with the first supporting member; and an elastic member for elastica

Abstract: An electrically operated power steering apparatus in a motor vehicle has a steering system for steering the motor vehicle, a steering torque detector for detecting a manual steering torque applied to the steering system, and an electric motor for generating an assistive torque to be transmitted as a steering assistive force to the steering system. An actual assistive torque detector detects an actual assistive steering torque which is actually transmitted from the electric motor to the steering system. A controller has at least a target assistive torque generator for generating a target value for an assistive torque to be generated by the electric motor depending on the manual steering torque detected by the steering torque detector, and generates a control signal based on the difference between the actual assistive steering torque detected by the actual assistive torque detector and the target value generated by the target assistive torque generator.

Abstract: A hydraulic power rack and pinion steering gear (10) includes a valve housing (32) and a hydraulic ram (20). The steering gear (10) further includes a composite plastic supporting body (12) which contains both the valve housing (32) and the hydraulic ram (20). The composite plastic supporting body (12) is formed of a high temperature thermoplastic binder material which is reinforced with glass fibers.

Abstract: A mechanism for supplying power assistance to the steering column of a vehicle is arranged to operate in response to signals indicating that power assistance is required, and therefore has periods in which it is inoperative and periods in which it is operative, all while the vehicle is in motion. The mechanism comprises a motor driving a speed reducing mechanism which is coupled to the steering column. The mechanism includes an epicyclic gear train, the planet wheel carrier of which is fitted around the steering column, the epicyclic gear train being driven by the power assistance motor. The outer crown of the epicyclic gear train is mounted so as to be free to rotate about the steering column, but when power assistance is required the outer crown is prevented from rotating by means of a releasable blocking or braking means actuated by an electro-magnet, thus causing the planet wheel carrier to rotate the steering column.

Abstract: An automotive power steering gear has a pair of permanent magnet driving discs supported on a housing of the steering gear and continuously rotated in opposite directions corresponding to right and left turn rotation of an output shaft of the steering gear. A soft, magnetically permeable driving disc is supported on the housing between the driving discs for rotation and for bodily shiftable movement toward and away from respective ones of the driving discs. The driven disc is drivingly connected to the output shaft of the steering gear. When steering effort is applied at a steering wheel connected to an input shaft of the steering gear, a cam and follower apparatus bodily shifts the driven disc toward the one of the driving discs rotating in the direction corresponding to the direction of the applied effort. The rotating magnetic flux field of the driving disc intercepts the driven disc and induces thereon a magnetic steering assist torque in the direction of the applied effort.

Abstract: An electric power steering apparatus includes a gear wheel on a driven side having a gear portion on one side surface thereof on a steering shaft and a pinion to be laterally meshed with a gear portion of the gear wheel on a shaft capable of transmitting a rotational driving force from an electric motor. The gear wheel and the pinion constitute a gear mechanism for transmitting a rotational force as a gear pair with non-parallel, non-intersecting axes. The gear wheel is axially supported on the steering shaft so as to be coupled in only a rotational direction and movable in an axial direction of the shaft. A biasing unit is provided on the other side of the gear wheel opposite to a portion of the pinion to be meshed with the gear portion and laterally urges the gear wheel toward the pinion.

Abstract: Apparatus for controlling the steerable wheels of a power-assisted steering unit of a vehicle in which an angle detector is connected to the power assist unit and to a power controller. An abnormality detector is arranged between the steering shaft of the steering wheel and an output shaft of the angle detector to detect an abnormal state based on relative displacement of the steering shaft and the output shaft of the angle detector to produce a signal which is sent to the power controller. The steering shaft is controlled by the power controller to avoid the abnormal state based on the signal from the abnormality detector, a control signal from an electronic control unit based on steering angle of the wheels and a signal from a sensor detecting steering angle of the steering wheel.

Abstract: In a hydraulic pressure switch mechanism connected between a steering shaft and a rack, an input shaft is covered with a balance sleeve, to form a sealing portion. The balance sleeve is covered with a valve outer spool, thereby forming a variable orifice. The hydraulic pressure switch mechanism requires no valve inner spool. The hydraulic pressure switch mechanism has a small and simple structure and provides secure hydraulic pressure control, thus contributing to reduction in manufacturing cost.

Abstract: A power-assist device for an automotive steering system employs an easy-to-assemble hydraulic pressure control valve to compensate for differential forces on opposite sides of an actuating piston in an unbalanced hydraulic cylinder. The piston divides the cylinder into first and second working chambers which are each connected to a hydraulic pump and a return reservoir via first and second spool valves, respectively. The spool valves are actuated axially by a torsion bar connected to the stub shaft of the steering column, so that they reciprocate axially within bores through the valve body as the steering wheel is turned back and forth. Lands on the spool valves oppose slightly larger lands the bores to define orifices which control the rates of hydraulic supply and drain to and from the working chambers of the cylinder.

Abstract: In a valve assembly of a power steering device, the center line of a cylindrical bore of a valve sleeve intersects the center line of a radially extending pin hole in the valve sleeve and is displaced from the center line of the valve assembly toward the side of the sleeve opposite to the pin hole. The valve sleeve is thicker at its periphery adjacent to the pin hole, thereby increasing the engagement length of a drive pin with the pin hole. Consequently, the pressure-receiving area of the pin hole is increased, and the unit area engagement force of the valve sleeve is thus reduced. The bending moment on the drive pin is also reduced, which adds to the durability of the drive pin. Since a bearing stress is thus reduced, a driver never feels unexpected reaction, due to wear, applied to a steering wheel while the driver is manually turning the steering wheel.

Abstract: A hydraulic cylinder assembly for a steering axle includes a cylinder having a piston disposed therein for selective axial movement. The piston is connected to a steering rod which extends outwardly from the ends of the cylinder. The ends of the steering rod are connected through links to respective knuckle assemblies pivotably mounted on the ends of the steering axle. Movement of the piston within the cylinder causes corresponding axial movement of the steering rod and pivoting of the knuckle assemblies to effect steering. A pair of piston stops are disposed within the cylinder at the ends thereof for limiting the axial movement of the piston. The piston stops are generally annular in shape, having one or more radially inwardly deformed portions provided therein. The deformed portions facilitate the installation of the piston stops into the cylinder during assembly. The axial lengths of the piston stops determine the desired limits for the axial movement of the piston within the cylinder.

Abstract: A servo assisted power steering system for motor vehicles comprising a steering-wheel shaft (2) which is connected via a rotary slide valve (6, 7, 8) and a worm-gear spindle (4) of a steering gear (5). The rotary slide valve controls the pressure impacting on a working piston (15) in a hydraulic power boost device. A power takeoff shaft (20) of an electric motor (21) is connected with the rotary slide (7) of rotary slide valve. In case of a rotary motion of steering-wheel shaft (2), a sensor (22) so activates electric motor (21) that a small counterforce is generated upon rotary slide (7) and that force works against the rotary motion of steering-wheel shaft (2). After completion of the rotary motion of steering-wheel shaft (2), as the steering wheel is let go, rotary slide (7) is moved back all the way into its neutral position by the electric motor.

Abstract: A variable effort power steering gear including detent elements in radial sockets in a pinion head, detent grooves in a stem of a stub shaft, an annular low speed reaction piston on the pinion head engageable on the detent elements when the low speed piston moves in a first direction, and an annular high speed reaction piston on the pinion head engageable on the detent elements when the high speed piston moves in a second direction opposite the first direction. Low and high speed bias springs apply first and second bias forces against the low and high speed reaction pistons. A control effects a fluid pressure gradient across the high speed piston in a low speed range of the steering gear counter to the second bias force so that in the low speed range only the first bias force is operative to urge the detent elements into the detent grooves and in the high speed range both the first and the second bias forces are operative to urge the detent elements into the detent grooves.

Abstract: A variable effort automotive power steering gear including an input or stub shaft, an output shaft or pinion head, a torsion bar between the stub shaft and pinion head defining an open-center position of one relative to the other, and detent reaction apparatus between the stub shaft and pinion head. The detent reaction apparatus includes a radial socket in a cylindrical wall of the pinion head, a detent groove in a stem of the stub shaft in the cylindrical wall, an insert rotatably supported in the radial socket with an eccentric bore offset from the centerline of the radial socket, and a detent element slidably supported in the eccentric bore in the insert and having a spherical end adapted to seat in the detent groove. The spherical end of the detent element is centered in the detent groove by rotating the insert until the detent element is at an innermost radial position.

Abstract: A variable effort automotive power steering gear including an input or stub shaft, an output shaft or pinion head, a torsion bar between the stub shaft and pinion head defining an open-center position of one relative to the other, and detent reaction apparatus between the stub shaft and pinion head. The detent reaction apparatus includes a radial socket in a cylindrical wall of the pinion head, a detent groove in a stem of the stub shaft in the cylindrical wall, an insert rotatably supported in the radial socket with an eccentric bore offset from the centerline of the radial socket, and a detent element slidably supported in the eccentric bore in the insert and having a spherical end adapted to seat in the detent groove. The spherical end of the detent element is centered in the detent groove by rotating the insert until the detent element is at an innermost radial position.

Abstract: A steering apparatus capable of changing a steering angle ratio of dirigible road wheels relative to a rotation amount of a steering wheel. The steering apparatus includes an input member arranged to be operatively connected to the steering wheel, a support shaft coaxially arranged with the input member and being interconnected with the input member for relative rotation on aligned axes, an output pinion rotatably mounted on the support shaft and being in mesh with the toothed portion of a rack member for operative connection with the dirigible road wheels, and a differential gear mechanism including an input sun gear mounted on the support shaft at a position adjacent the output pinion, first and second planetary gears respectively in mesh with the input sun gear and the output pinion and being rotatably mounted on a common shaft, and a carrier supporting thereon the common shaft and being arranged to be rotated about the support shaft.

Abstract: A power steering system is provided in which the rack portion of the power piston is strengthened while still shortening the axial length of the power piston associated therewith. This is accomplished by providing a control valve which includes a valve lever received in a power piston of the device which is relatively rotatable with respect to the power piston and moves in an axial direction of the housing with the power piston in response to rotation from an input shaft connected with the steering wheel. The valve lever has an engaging portion which projects outside of the power piston so as to be connected therewith when the valve reciprocates. The reciprocation of the valve will assist in the operation of the power steering unit and provide the power assist. The valve lever has a portion engageable with a pin member received in the valve spool of the control valve so as to reciprocate the control valve.

Abstract: A boat steering assembly (10) having a substantially circular rotary gear (12) engaging an output gear such that the leverage is varied between the output gear (16, 16') and the steering wheel (32). The steering wheel (32) has a shaft gear (28) engaging in idler gear (22) which eccentrically rotates the circular gear (12) about the first axis (14). The eccentrically rotating circular gear (12) engages the output gear (16, 16') having a partially sinusoidal profile thereby automatically varying the distance (i.e., leverage) between the first axis (14) and a point of contact (52) between the circular (12) and output (16, 16') gears.

Abstract: A clutch having an outer ring, an inner shaft mounted in the outer member, a cage interposed between the outer ring and the inner shaft and cam members movably mounted in pockets formed in the cage. A torque-setting elastic member is provided between the cage and one of the outer ring and the inner shaft so that while the torque on the elastic member is smaller than a preset value, they will rotate in unison with some clearance left therebetween in the direction of rotation. When the torque on the elastic member gets larger than the preset value, the elastic member deforms to allow the cage to turn relative to the member engaged therewith. Now, the cam elements are pushed by the cage into engagement with both cam surfaces formed on the inner periphery of the outer member and the other periphery of the inner member, thus bringing the two members into engagement. This input shaft is rotatably mounted in the outer ring by means of two bearings so as to extend through the outer ring.

Abstract: A fluid power assisted rack and pinion steering system includes a steering gear assembly having a valve core, a valve sleeve, and an axially extending torsion bar. The input shaft of the steering gear is formed as the valve core, and one end of the torsion bar is pinned to the input shaft before the valve is balanced. A pinion is connected to and rotates with the valve sleeve, and the other end of the torsion bar is rotationally fixed to the pinion. The pinion has an axially extending tapered bore in which is received a matching tapered portion of the torsion bar. The tapered portion of the torsion bar engages the tapered portion of the bore in the pinion in a rotationally fixed locking engagement. Upon assembly of the steering gear, if the valve is not properly balanced, the tapered connection is easily loosened to adjust the relative angular orientation of the pinion to the torsion bar, and then retightened to again fix the torsion bar to the pinion.

Abstract: A steering gear and system for a vehicle having steerable roadwheels located on more than one axle includes a control module, a rotary motor responsive to signals from the control module for providing power for steering the roadwheels, and a nonreversible gearset powered by the motor for converting rotary motion of the motor into linear motion for steering the roadwheels, with the motor being capable of driving the gearset but with the gearset being incapable of driving the motor in response to force inputs from the roadwheels into the gearset.

Abstract: In a power assistance system for a vehicle steering mechanism fluid pressure providing the assistance is supplied from a pump driven intermittently by an infinitely-variable electric motor. For a rack and pinion mechanism fluid pressure chambers are formed by sealing boots at each end of the rack, and are connected through the pump, which is operative to create a pressure differential between the chambers, and thus across the rack to provide power assistance. The electric motor is energized as required to drive the pump in the appropriate direction, and when the motor and pump are inoperative fluid is allowed to flow freely between the chambers to accommodate fluid displacement as a result of unassisted operation of the steering. The pump is preferably a turbine pump, which allows fluid flow when inoperative. The system provides power assistance efficiently, and relatively cheaply.

Abstract: A steering angle middle point detecting apparatus of the invention is provided with a vehicle speed sensor for detecting vehicle speed, a torque sensor for detecting at regular intervals steering torque to be added to a steering wheel, a steering position detecting means for detecting a steering position of a steering mechanism, a means for comparing a steering torque set value previously set corresponding to the vehicle speed with the steering torque detected by the torque sensor, and a steering angle middle point calculating means for calculating a middle point of a steering angle by using the steering position of the steering mechanism detected by the steering position detecting means when the steering torque is smaller than the steering torque set value, which judges that the vehicle goes straight when the detected steering torque is smaller than the steering torque set value corresponding to the vehicle speed, and judges the steering position at that time to be the middle point of the steering angle.

Abstract: A hydrostatic auxiliary power steering mechanism for motor vehicles is described, in which the steering cylinder power is controlled by a servo mechanism for which a control loop is provided for regulating oil quantity proportional to the turning of the steering wheel. This control loop is connected in parallel to a hand pump driven by the steering wheel. In this way, the transmission ratio of the hand pump can be selected independently of the auxiliary power control loop in such a way that the vehicle remains steerable in all operating conditions. Moreover, there results the possibility of designing the auxiliary power control loop with external feedback in such a way that disturbance variables of a control system comprising the steering valve, the steering cylinders and the steering linkage can be controlled.

Abstract: A power-assist device for an automotive steering system employs spool valves with different external diameters to control the fluid pressure in smaller and larger area chambers of a pressure control valve which controls pressure in an unbalanced cylinder device. The different size of spool valves are disposed within different sizes of bores formed through a housing of the pressure control valve for defining wider fluid path area for introducing larger amount of working fluid into the smaller area chamber in comparison with that for the larger area chamber and narrower fluid path for draining the working fluid in the smaller area chamber for lower drainage rate in comparison with that for the larger area chamber.

Abstract: In a steering gear having a steering correction function for causing a vehicle to correct steering when disturbance acts on a power steering gear or the vehicle, there are provided a connecting portion for connecting the input shaft to output shaft and for detecting the abnormal state; and a releasable portion for a drive unit operation of the steering drive unit interlocked with a connecting operation of the connecting mechanism. In a normally "OFF" (disengagement) state of the clutch, a steering drive control device controls a steering drive unit in accordance with a steering command from a steering control device, and a steering driving force is transmitted from the steering drive unit to the steering device through a transmissional mechanism for the steering driving force, thereby performing steering. However, in an abnormal state, the clutch mechanically detects the abnormal state and is engaged from the "OFF" state to an "ON" (engagement) state to connect the input device and the steering device.