Expansible Chamber Type Volumetric Responsive Measuring Device In Series With Or Driven By Output Motor Operates The Motor Controller Patents (Class 60/384)
  • Patent number: 4359866
    Abstract: Axially spaced and aligned longitudinal distributor grooves are formed in the radially outer surface of a thin-walled tubular valve element in angularly spaced relation to internal grooving of the valve element for conducting pressurized fluid and establishing a torsional coupling in a hydrostatic controller associated with a power steering system. Obliquely orientated bores in the valve housing establish fluid communication between the longitudinal grooves adjacent opposite axial ends of the housing and axial passages in the housing.
    Type: Grant
    Filed: April 2, 1980
    Date of Patent: November 23, 1982
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventor: Werner Tischer
  • Patent number: 4356759
    Abstract: A hydraulic control system of a transport vehicle, wherein the flow of hydraulic fluid from the source of pressure is fed to the servomotor through a control hydraulic circuit which incorporates a fluid directional control device mechanically linked to a steering unit of a transport vehicle, a number of hydraulic lines and at least one throttle regulator, and through the actuating hydraulic circuit which incorporates a number of hydraulic lines, a throttle regulator and a discrete-type three-position fluid directional control device controlled by a pressure of the fluid flows admitted along the hydraulic lines communicated with the fluid directional control device of the control hydraulic circuit.
    Type: Grant
    Filed: March 14, 1978
    Date of Patent: November 2, 1982
    Inventors: Boris A. Ljubimov, Evgeny N. Chervyakov, Jury I. Sudakov, Valery Y. Obidin, Iraida S. Pogorelova, Grigory E. Ogy, Leonid A. Vainshtein, Lazar A. Pann
  • Patent number: 4355505
    Abstract: Axially spaced distributor grooves externally formed on a rotatable controller valve element conduct pressurized fluid to a servomotor in response to axial displacement of the valve element within a housing enclosing pressurized spaces to which opposite axial ends of the valve element are exposed. Flow of the pressurized fluid through the grooves is controlled by slide valve surfaces on the valve element axially between the pressurized spaces and the grooves.
    Type: Grant
    Filed: April 2, 1980
    Date of Patent: October 26, 1982
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventors: Karl-Heinz Liebert, Werner Tischer
  • Patent number: 4354350
    Abstract: In a steering control valve device of the kind utilizing a metering pump and a torsional stress means for returning the flow control valve sleeve to a neutral position, there is provided a coupling sleeve between the manually operable steering spindle and the valve sleeve. Such coupling sleeve is for the purpose of providing an intermediate actuating member between the steering spindle and the valve sleeve to overcome errors in alignment and other disadvantages which can occur in conventional constructions where the steering spindle directly actuates the valve sleeve wherein rotation of the steering spindle effects axial shift of the valve sleeve for flow control purposes. The invention is particularly advantageous where the means of translating rotary motion of the steering spindle to axial movement of the valve sleeve is effected by threaded coaction.
    Type: Grant
    Filed: May 7, 1980
    Date of Patent: October 19, 1982
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Werner Tischer, Karl-Heinz Liebert
  • Patent number: 4345614
    Abstract: The invention relates to hydraulic steering apparatus of the type having valve gear for selectively directing pressurized fluid to and from opposite sides of a servomotor connected to vehicle wheels to be steered. This type of steering apparatus only requires pressurized fluid when actuated and may provide an auxiliary circuit with pressured fluid at times when it is not being actuated. Priority valves give priority to the steering apparatus. During extended intervals when pressured fluid is supplied to an auxiliary circuit, parts of the steering apparatus are subjected to substantial cooling. Then when the priority valve diverts hot pressurized fluid from the auxiliary circuit to the cooled steering apparatus the temperature differential causes an adverse effect on the steering apparatus by creating a tendency for binding of parts due to the unequal expansion of valve sleeves.
    Type: Grant
    Filed: August 18, 1980
    Date of Patent: August 24, 1982
    Assignee: Danfoss A/S
    Inventors: Niels G. Karlberg, Poul H. H. Pedersen
  • Patent number: 4344283
    Abstract: An auxiliary steering flow control device having known features of a rotatable steering spindle which initially effects axial shift of a valve sleeve through a torsional stressing device acting on a pair of compressibly arched leaf springs longitudinally disposed on the axis of the steering spindle and carried in a holder within the steering spindle. The leaf springs have contiguous contacting arched surfaces on the steering spindle axis and the arched configuration effects a back to back pretensing that augments the potential energy that can be stored in the springs, particularly in arched surface contiguity with each other.
    Type: Grant
    Filed: May 7, 1980
    Date of Patent: August 17, 1982
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Karl-Heinz Liebert, Werner Tischer, Christoph Deppenbrock
  • Patent number: 4336687
    Abstract: A load sensing controller is disclosed of the type which may be used in a hydrostatic power steering system. The controller housing includes a valving arrangement (29) and a fluid meter (31), through which fluid is delivered to a steering cylinder (15). A controller housing (63) defines a load signal port (25) which is connected to a load sensing flow control valve (39) to vary the rate of fluid delivery to the controller. During normal operation, a steering load signal is sensed downstream of a variable flow control orifice (131) and communicated through a shuttle valve assembly (151) to the load signal port (25). When the steering cylinder is subjected to an overrunning load, an increased load signal is sensed upstream of a variable orifice (136) and the shuttle valve assembly communicates this increased load signal to the load signal port to increase the rate of fluid delivery to the controller to prevent cavitation.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: June 29, 1982
    Assignee: Eaton Corporation
    Inventor: David F. Morgan
  • Patent number: 4311171
    Abstract: A hydrostatic steering controller including a pair of valve members which are relatively movable in opposite directions from a neutral position to a pair of operating positions to control flow between a fluid pressure source and a hydraulic steering motor. In each of the operating positions the valve members include interfacing surfaces which define part of a first passage directing high pressure fluid to the steering motor and a second passage directing low pressure fluid from the steering motor to a reservoir. The interfacing surfaces of the valve members create a pressure dam between the first and second passages when the valve members are relatively moved by a predetermined amount away from the neutral position and to an operating position. The pressure dam minimizes leakage between the first and second passages. The pressure dam is created in a pressure dam groove formed in a surface of one of the valve members.
    Type: Grant
    Filed: September 22, 1978
    Date of Patent: January 19, 1982
    Assignee: TRW Inc.
    Inventor: Maurice P. Roberts
  • Patent number: 4297845
    Abstract: The invention relates to a hydrostatic control unit of the metering type utilized for some automotive type power steering systems. The control unit has a valving section with inlet and outlet ports connectable to a pump and a tank and two working ports connectable to opposite sides of a bidirectional servomotor which is connectable to wheel steering linkage. A metering motor controlled by the valving section supplies and exhausts metered fluid to and from the servomotor through the two working ports of the valving section. The valving section has a single movable slide element cooperable with a stationary housing member. A gearing unit which may be of the planetary type is provided having two inputs and one output with the two inputs being connectable to the vehicle steering wheel and the metering motor input shaft and the output being connectable to the slide valve element.
    Type: Grant
    Filed: November 26, 1979
    Date of Patent: November 3, 1981
    Assignee: Danfoss A/S
    Inventor: Erik Kyster
  • Patent number: 4290738
    Abstract: A torsion rod is provided with articulated connections at opposite ends to transmit torque between a steering spindle and the universal shaft coupling of a pump rotor in a steering control valve. The end of the torsion rod coupled to the universal shaft is received in a bore that terminates close to the driven end of the universal shaft engaged with the pump rotor, the articulated connection to the torsion rod being located at said terminal end of the bore.
    Type: Grant
    Filed: September 10, 1979
    Date of Patent: September 22, 1981
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Karl-Heinz Liebert, Werner Tischer
  • Patent number: 4286684
    Abstract: PCT No. PCT/US80/00228 Sec. 371 Date Mar. 3, 1980 Sec. 102(e) Date Mar. 3, 1980 PCT Filed Mar. 3, 1980A hydraulic servo steering system (10) for vehicles has a steering valve (24) for directing fluid to steering cylinders (16,17) in response to pilot fluid directed to one end of the steering valve (24) from a hand metering unit (31). A servo cylinder (19) directs a volume of fluid to the other end of the steering valve (24) sufficient for returning the steering valve (24) to its centered position in response to turning of the vehicle. A pair of pilot operated check valves (53,54) positioned in the lines (51,52) between the servo cylinder (19) and the steering valve (24) are opened in response to fluid pressure being established in the lines (51,52) by a means (71). Should one of the lines (51,52) rupture, the resultant drop in fluid pressure in the lines (51,52) causes the check valves (53,54) to close thereby isolating the steering valve (24) from the ruptured lines (51,52).
    Type: Grant
    Filed: March 3, 1980
    Date of Patent: September 1, 1981
    Assignee: Caterpillar Tractor Co.
    Inventor: Lawrance F. Berg
  • Patent number: 4270349
    Abstract: The distributing device of a vehicle hydraulic control system comprises a distributor connected via hydraulic lines to a servomotor, a pump and a tank, the control member of the distributor being mechanically connected with the steering drive shaft, and further includes a hydraulic machine connected via hydraulic lines with the hydraulic distributor, the rotary member of this machine being adapted to vary the volume of the working chambers and being mechanically connected with the actuating member of the hydraulic distributor and with the steering drive shaft, the steering drive shaft being rotatable relative to the rotary member of the hydraulic machine within an angular play value providing for the preset displacement of the control member of the hydraulic distributor.
    Type: Grant
    Filed: March 14, 1978
    Date of Patent: June 2, 1981
    Inventors: Boris A. Ljubimov, Evgeny N. Chervyakov, Jury I. Sudakov, Iraida S. Pogorelova, Petr Y. Pritsker, Igor I. Kandrusev, Zilek B. Liberfarb
  • Patent number: 4266464
    Abstract: The invention relates to hydraulic control apparatus for a servomotor of the type utilized for vehicle steering systems. Such apparatus has a control circuit controlled by a manually operated device such as a steering wheel and a power circuit connected between the servomotor and a power source such as a hydraulic pump. The power circuit includes resetting apparatus for throttling the return flow branch in a manner so that forces applied to the servomotor in the same direction as actuation are absorbed with a minimum of reactionary movement by the valves on the return flow side of the apparatus.
    Type: Grant
    Filed: June 5, 1978
    Date of Patent: May 12, 1981
    Assignee: Danfoss A/S
    Inventors: Johannes V. Baatrup, Thorkild Christensen, Tage Christiansen, Svend E. Thomsen
  • Patent number: 4253540
    Abstract: PCT No. PCT/US79/00920 Sec. 371 Date Oct. 29, 1979 Sec. 102(e) Date Oct. 29, 1979 PCT Filed Oct. 29, 1979A steering system (36) for vehicles (10) in which a device (90) is provided for circulating fluid through the system when operating in a cold environment. The system includes a hand metering unit (58) which is connected to opposite ends of a pilot operated steering valve (42) through a pair of pilot lines (60,62). A pressure reducing valve (94) maintains a continuous flow of fluid to the pilot lines (60,62) at a first predetermined pressure level. A pressure responsive valve (94) positioned between the hand metering unit (58) and a reservoir (40) intermittently passes pilot control fluid, returned to the hand metering unit (58) from the pilot actuation of the steering valve (42), to the reservoir (40) in response to the pressure of such returned fluid reaching a second slightly higher predetermined pressure level such as occurs when the fluid in the system is cold.
    Type: Grant
    Filed: October 29, 1979
    Date of Patent: March 3, 1981
    Assignee: Caterpillar Tractor Co.
    Inventor: Lawrance F. Berg
  • Patent number: 4232708
    Abstract: A controller for controlling fluid flow from a source to a motor, such as the steering motor of a motor vehicle. The controller includes a metering section and a control valve section comprising a stacked assembly of plate valve members which control flow and, along with the metering section, define the outer periphery of the controller, and minimize the need for complex cast housing members. The controller is compact and yet is constructed to respond to an input signal from an input shaft to direct needed flow from the source to the primary steering motor, and excess flow to an auxiliary motor. The controller is also characterized by a unique spring centering mechanism which applies a spring centering force to the assembly of plate valve members. Additionally, the controller is characterized by a special seal arrangement for resisting leakage of high pressure fluid about the input shaft, and by structure for forming pressure dams to resisting leakage of metered fluid.
    Type: Grant
    Filed: June 25, 1979
    Date of Patent: November 11, 1980
    Assignee: TRW Inc.
    Inventor: Laurence L. Miller
  • Patent number: 4221159
    Abstract: A control valve assembly having relatively displaceable valve elements through which control passages establish fluid flow paths to a steering servomotor for supply of metered fluid to the pressurized side of the servomotor and exhaust of fluid from the contracting side to an internal low pressure space in the valve assembly. The control passages in the valve elements are protectively located between supply passages under full pump pressure to prevent loss of fluid as a result of leakage from the control passages.
    Type: Grant
    Filed: November 2, 1978
    Date of Patent: September 9, 1980
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventor: Karl-Heinz Liebert
  • Patent number: 4176520
    Abstract: A drive system is provided for driving the pump rod of a deep well pump. The drive system includes a lift cylinder having a piston movable therein connected to the pump rod of the well pump. The lift cylinder piston is driven by fluid pressure provided from a motor having a piston slidable within a cylinder. The motor piston is driven by fluid pressure provided by a pump. A control valve is operated in response to the movement of the lift piston to control the flow of fluid from the pump to the motor. A pressure relief valve is connected between the pump and the motor and diverts fluid pumped by the pump from the motor when the fluid pressure between the pump and the motor exceeds a predetermined level. A vent is provided in the lift cylinder above the piston to permit the free movement of the lift cylinder piston during operation and to accommodate movement of the lift piston caused by expansion of fluid and gases in the system.
    Type: Grant
    Filed: February 27, 1978
    Date of Patent: December 4, 1979
    Inventor: James B. Horton
  • Patent number: 4174612
    Abstract: The invention provides a pressure flow control valve for a booster steering system which effects an extended traverse of movement of concentric coacting valve sleeves relative to each other by a combined axial and rotary movement of the inner sleeve in order to smooth out the flow under control in pressurizing a servomotor, thus achieving an improved, or flatter, regulation curve characteristic, wherein a safe road reaction resistance to steering is effected, and wherein undesirable pressure fluctuations in the system are minimized as compared with prior art valving to reduce compressional vibration in the hydraulic system.
    Type: Grant
    Filed: March 24, 1978
    Date of Patent: November 20, 1979
    Assignee: Zahnradfabrik Friedrichshafen AG
    Inventor: Karl-Heinz Liebert
  • Patent number: 4159723
    Abstract: The invention relates to a vehicle steering control device of the type having a housing, inner and outer rotary slide members disposed in a bore of the housing and forming a reversing switch. The housing has inlet and outlet ports and two motor ports. Four axially adjacent spaced grooves being in the interface between the bore of the housing and the outer rotary slide member with the first and fourth grooves being connected to the inlet and outlet ports and second and third grooves being connected to the two motor ports. A steering shaft is connectable to the inner rotary slide member and a measuring motor which, on actuation of the control device, is connected to the inlet port to cause the outer rotary slide member to follow the inner rotary slide member.
    Type: Grant
    Filed: February 3, 1978
    Date of Patent: July 3, 1979
    Assignee: Danfoss A/S
    Inventors: Johannes V. Baatrup, Ivar Rasmussen
  • Patent number: 4144712
    Abstract: The invention relates to a power steering system of the metering type. Units of this type most commonly utilize gerotor type gear sets for the metering operation. During emergency operation when pressurized operating fluid is not available from a pump, steering is accomplished by operating the metering motor with the steering wheel which provides a pumping function for manually creating pressurized fluid. A problem with this type of unit is that a substantial amount of manual exertion is required to steer the vehicle under these conditions. Control units of this type have a universal drive between the rotatable valve thereof and the inner gerotor gear which has a combination rotating and orbiting movement. In this invention the universal drive has two main sections with a lost motion emergency device between the opposite ends.
    Type: Grant
    Filed: August 12, 1977
    Date of Patent: March 20, 1979
    Assignee: Danfoss A/S
    Inventor: Paul E. Termansen
  • Patent number: 4109679
    Abstract: A controller for fluid pressure operated devices such as power steering systems. The controller is of the type having a primary, rotatable valve member and a follow-up valve member and including a fluid meter having a metering member coupled to the follow-up valve member. The valving defines a central reference plane perpendicular to the axis of rotation of the valving, the primary valve member defining a pair of meter grooves oppositely and equally disposed about the plane. The follow-up valve defines pressure porting adjacent the plane and connected to the fluid inlet port.
    Type: Grant
    Filed: January 24, 1977
    Date of Patent: August 29, 1978
    Assignee: Eaton Corporation
    Inventor: Oliver W. Johnson
  • Patent number: 4103561
    Abstract: A method and apparatus for reducing shock loads to an operator of a vehicle during turning movement is disclosed herein. The method consists of increasing the mass of an actuator connected to a control element which controls flow of hydraulic fluid to a fluid motor that produces turning movement for the vehicle. The increased mass is spaced from the fixed rotational axis for the actuator which results in an increased moment of inertia for the actuator that resists acceleration and deceleration of the actuator thereby resisting rapid changes in turning movements for the vehicle.
    Type: Grant
    Filed: March 31, 1977
    Date of Patent: August 1, 1978
    Assignee: J. I. Case Company
    Inventor: Donald C. Baker
  • Patent number: 4096883
    Abstract: A closed-center controller is disclosed, especially of the type utilized in hydrostatic power steering systems. The controller includes valving which, in the neutral position, defines a bypass passage communicating inlet fluid through the interior of the hollow, primary valve member to the tank port of the controller. The bypass passage includes a variable bypass orifice having a maximum flow area in the neutral position of the valving and decreasing to zero as the valving is displaced from the neutral position. The variable bypass orifice permits the passage of just enough fluid, typically in the range of about 0.25 gpm to about 0.5 gpm, to minimize the temperature difference between the controller valving and the remainder of the hydraulic system, thus minimizing the possibility of thermal seizure of the valving within the controller.
    Type: Grant
    Filed: August 24, 1976
    Date of Patent: June 27, 1978
    Assignee: Eaton Corporation
    Inventor: James K. Yip
  • Patent number: 4050474
    Abstract: A controller for fluid pressure operated devices such as power steering systems is provided. The controller is of the type having an inlet for receiving a system fluid flow, an outlet, a pair of control fluid ports for connection to a primary fluid pressure operated device and an auxiliary fluid port for connection to an auxiliary fluid pressure operated device or system. The controller includes a valve means having a primary valve member and a follow-up valve member, the valve members defining a neutral position relative to each other. A fluid meter includes a movable member coupled to the follow-up valve member. The primary and follow-up valve members cooperate with the housing to define a first flow path including the inlet, one of the control fluid ports, the fluid meter, the other of the control fluid ports, and the outlet when the valve members are relatively displaced from the neutral position.
    Type: Grant
    Filed: April 16, 1976
    Date of Patent: September 27, 1977
    Assignee: Eaton Corporation
    Inventor: David F. Morgan
  • Patent number: 4043419
    Abstract: A power steering system is disclosed which selectively controls the flow of fluid to a steering motor and an auxiliary device, and may have as its source of pressurized fluid either a fixed displacement pump, a variable displacement pump, or a load sensing pump. The system includes a steering control valve disposed between the pump and the steering motor, and an externally pilot operated flow control valve, specifically, a priority valve, disposed between the pump and the steering control valve, such that the entire system flow enters the priority valve.
    Type: Grant
    Filed: June 4, 1976
    Date of Patent: August 23, 1977
    Assignee: Eaton Corporation
    Inventors: Bernard J. Larson, Oliver Wendell Johnson, James Kwok-fun Yip
  • Patent number: 4037620
    Abstract: A controller for fluid pressure operated devices such as hydrostatic power steering systems. The controller is of the type having a primary, rotatable valve member and a follow-up valve member, and further comprising a fluid meter including a metering member coupled to the follow-up valve member. The controller is of the 5-port type, having a load signal port for communicating a steering load signal and maintaining a constant pressure drop across the main control orifice of the controller. The primary and follow-up valve members define a central reference plane oriented generally perpendicular to the axes of rotation of the valve members and the various ports and passages defined by the valve members are arranged in somewhat of a mirror image of each other about the reference plane.
    Type: Grant
    Filed: June 23, 1976
    Date of Patent: July 26, 1977
    Assignee: Eaton Corporation
    Inventor: Oliver Wendell Johnson
  • Patent number: 4033377
    Abstract: A controller for fluid pressure operated devices such as power steering systems. The controller is of the type having a primary, rotatable valve member and a follow-up valve member, the valve members defining a neutral position. The follow-up valve member is coupled to the primary valve member for limited movement relative to the neutral position. The controller further comprises a fluid meter including a metering member for measuring the volume of fluid passing therethrough, the metering member being coupled to the follow-up valve member. The controller has an inlet port and first and second control fluid ports which may be connected to the opposite ends of the power steering cylinder.
    Type: Grant
    Filed: April 23, 1976
    Date of Patent: July 5, 1977
    Assignee: Eaton Corporation
    Inventor: Oliver Wendell Johnson
  • Patent number: 4016949
    Abstract: A control valve operated by the steering wheel to selectively connect a variable displacement pump for operating a hydraulic cylinder in each of two directions to steer the vehicle. The hydrostatic system is regenerative in steering of the hydraulic cylinder in one direction since both sides of the hydraulic cylinder are connected to the high pressure input line in steering in one direction. A pilot line is connected to the valve output to sense load pressure and feed back to the compensator of the variable displacement pump to vary the displacement in response to load demands of the hydrostatic system.
    Type: Grant
    Filed: November 24, 1975
    Date of Patent: April 12, 1977
    Assignee: Allis-Chalmers Corporation
    Inventors: John R. Plate, Charles P. Heisig
  • Patent number: 3960234
    Abstract: A controller for fluid pressure operated devices such as power steering systems is provided. The controller is of the type having an inlet for receiving a system fluid flow, an outlet, a pair of control fluid ports for connection to a primary fluid pressure operated device and an auxiliary fluid port for connection to an auxiliary fluid pressure operated device or system. The controller includes a valve means having a primary valve member and a follow-up valve member, the valve members defining a neutral position relative to each other. A fluid meter includes a movable member coupled to the follow-up valve member. The primary and follow-up valve members cooperate with the housing to define a first flow path including the inlet, one of the control fluid ports, the fluid meter, the other of the control fluid ports, and the outlet when the valve members are relatively displaced from the neutral position.
    Type: Grant
    Filed: September 18, 1974
    Date of Patent: June 1, 1976
    Assignee: Eaton Corporation
    Inventor: David Frederick Morgan
  • Patent number: 3959968
    Abstract: The invention is concerned with an improvement in a fluid controller for a power steering system which includes a housing having a fluid A for connection to the discharge side of a main fluid pump, an outlet for connection to the suction side of the main pump and a pair of ports for connection to the opposite sides of a dual acting hydraulic device such as a balanced cylinder of the power steering system for controlling the flow of pressurized fluid to the device. The controller includes a gear set which serves as a fluid meter or as a manual pump, depending upon the operativeness of the main fluid pump, and a spool valve shiftable axially to control the flow through the inlet, the gear set, the cylinder ports and the outlet. A control shaft is mounted for rotation on the housing responsive to movement of a steering wheel and is coupled to the spool valve for effecting axial shifting of the spool valve in response to rotation of the control shaft.
    Type: Grant
    Filed: April 25, 1975
    Date of Patent: June 1, 1976
    Assignee: Caterpillar Tractor Co.
    Inventor: Jonny R. Greiner
  • Patent number: 3957129
    Abstract: A vehicle steering system comprises a set of steering cylinders which, when actuated, effect vehicle steering. The set of steering cylinders comprises at least two proportionately sized cylinders. The proportionate sizing of the cylinders is determined by the rod-end area to head-end area ratio of the cylinders. A steering control means directs two different flows to the respective cylinders in accordance with the proportionate sizing thereof to effect actuation thereof for steering purposes. One of these flows is directed to the head end of one cylinder and the other flow is directed to the rod end of the other cylinder. The steering control means also receives the return flow from the proportionately sized cylinders.
    Type: Grant
    Filed: February 7, 1974
    Date of Patent: May 18, 1976
    Assignee: TRW Inc.
    Inventor: Jim L. Rau
  • Patent number: RE30992
    Abstract: The present invention relates to a control unit for a vehicle powersteering mechanism comprising a housing having an inlet for connection to a source of fluid under pressure, an outlet for returning hydraulic fluid under pressure to said source, a pair of ports for connection to a hydraulic servomotor the movement of which controls the steering of the dirigible wheels of the vehicle, a hydraulic motor provided with a rotatable element and a follower element in operative combination with a distributor valve means provided with at least one displaceable body, said combination being operable on rotation of a control shaft connected thereto to divert hydraulic fluid flowing from said inlet through said housing to said outlet to one of said ports, and thus to its associated chamber of said servomotor, via said hydraulic motor, the hydraulic fluid being exhausted from the other chamber of the servomotor to said outlet, via said other port.
    Type: Grant
    Filed: November 9, 1979
    Date of Patent: July 13, 1982
    Assignee: Riva Calzoni S.p.A.
    Inventor: Battista Bertanza
  • Patent number: RE31067
    Abstract: A control unit for controlling fluid flow to a fluid motor and for producing a flow proportional to the rate of rotation of an input shaft and for applying a pressure to the fluid motor proportional to the applied torque on the input shaft. The control unit includes a valve means for directing fluid to a fluid motor in response to rotation of the input shaft. The valve means includes a fixed valve part and a movable valve part. The movable valve part is moved to effect actuation of the valve through a gerotor gearset mechanism which also functions to meter the flow of fluid which is directed to the fluid motor.
    Type: Grant
    Filed: July 20, 1977
    Date of Patent: October 26, 1982
    Assignee: TRW Inc.
    Inventor: Maurice P. Roberts