US3801239A - Controller for fluid operated device - Google Patents

Controller for fluid operated device Download PDF

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Publication number
US3801239A
US3801239A US00240418A US3801239DA US3801239A US 3801239 A US3801239 A US 3801239A US 00240418 A US00240418 A US 00240418A US 3801239D A US3801239D A US 3801239DA US 3801239 A US3801239 A US 3801239A
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United States
Prior art keywords
externally toothed
fluid
controller
toothed member
pressure
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Expired - Lifetime
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US00240418A
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English (en)
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B Larson
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Eaton Corp
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Eaton Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
    • B62D5/09—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by means for actuating valves
    • B62D5/093—Telemotor driven by steering wheel movement
    • B62D5/097—Telemotor driven by steering wheel movement gerotor type

Definitions

  • a controller for a fluid pressure operated device has a section for metering control fluid through the controller to the pressure operated device.
  • the meter section [52] 418/61 60/384 180/792 R of the controller is enclosed in a pressurizable hous- [51] Int.
  • the present invention relates generally to controllers for fluid pressure operated devices such as hydrostatic steering systems, where a mechanical input signal is converted to a mechanical output signal solely by the metering of pressurized hydraulic fluid without a mechanical interconnection between the input and the output. More specifically, this invention relates to a controller of the above general type having means for preventing slip between input and output and for creating a travel limit stop.
  • I travel limit slip a phenomena which may be called I travel limit slip.
  • the cylinder attached to the vehicle wheels reaches the end of its stroke, the steerable vehicle wheels have reached the limit of their travel.
  • the rate of steering wheel rotation at this position is known as travel limit slip rate and is measured in revolutions per minute of the steering wheel.
  • the controller is generally of the type shown in U. S. Reissue Pat. No. 25,126 entitled Controller for Fluid Pressure Operated Devices, issued Feb. 20, 1962 to Lynn L. Charlson and assigned to the assignee of the present invention.
  • Travel limit slip rate may be defined as the rate in RPMs at which the steering wheel of a totally hydraulic steering system will continue to rotate after the mechanical portions of the steered wheels have reached the limits of travel. This phenomenon occurs primarily because of the failure of a totally hydraulic steering system to provide a direct mechanical connection between the steering wheel and the steered wheels of the vehicle.
  • the primary purposes for this invention are to reduce leakage in the meter section of a controller, to provide a travel limit stop in controllers for fluid pressure operated devices and to extend the operating pressures for such controllers.
  • the meter section of the controller is enclosed in a pressurizable housing. With the meter thus enclosed, the external surfaces of the metering section can be subjected to full system pressure by allowing pressure from one of the pockets of the meter displacement element to communicate with the interior chamber of the housing.
  • the increase of fluid pressure due to bottoming of the steering cylinder may be used to provide a frictional braking force resisting further movement of the meter element to provide a travel limit stop.
  • Another object of the present invention is to provide a fluid controller having a metering portion for meter-' ing control fluid to the fluid operated device and wherein the cotroller has means for both radially and axially pressure biasing the metering elements into engagement and wherein the biasing pressure is substantially equal to or greater than the control fluid pressure and acts through differential pressure areas to create a biasing force for accomplishing the above-stated pur pose.
  • Another object of the present invention is to provide an improved controller for fluid pressure operated devices wherein the controller has a metering section which measures the volume of fluid flow to the fluid operat ed device and including means operable to apply fluid pressure to the metering section of the controller to prevent leakage between movable and stationary meter surfaces and thereby insure a more precise metering control fluid passing to the fluid pressure operated device.
  • FIG. 1 is a schematic representation of the controller of the present invention disposed in a hydraulic circuit.
  • the present invention is preferably used in hydrostatic steering system to provide a better position reference between a steering wheel of the vehicle and the steered wheels of the vehicle to thereby eliminate travel limit slip and provide a travel limit stop in a hydraulic steering system without the necessity of a mechanical interconnection between the steering wheel and the steered vehicle wheels.
  • the controller is indicated in its entirety by the numeral 10 and, for the purpose of the present'example, is illustrated in FIG. 1 as used in a power steering mechanism of the vehicle (not shown).
  • the controller 10 has a housing or body structure 12 having an inlet 13 to which is connected a conduit 14 to which fluid under pressure is introduced to the controller 10 from a suitable source, such as a pump 15 that is connected to a reservoir or tank 16 by conduit 17.
  • the casing 12 is further provided with an outlet 18 for return of fluid to the tank or reservoir 16 through a conduit 19 suitably connected to the outlet 18.
  • the casing 12 has a pair of ports 20 and 21 to which the respective conduits 22 and 23 are connected, these conduits lead to opposite ends of a hydraulic cylinder 24 having mounted for axial reciprocatory movement therein a piston equipped plunger rod 25.
  • the plunger rod 25 is adapted to be connected to a steering link 26 of the vehicle (not shown), by means of the usual bell crank 27 and rigid link 28.
  • the steering linkage 26 is connected to the steerable wheels 29 in the usual manner.
  • the housing or body structure 12 comprises a tubular section 30 for defining the inlet and outlet 13 and 18 respectively and the ports 20 and 21.
  • a pressure relief valve 31 is provided between conduits l4 and 19. The relief valve setting is approximately three times as high as normal system working pressure of the controller 10.
  • the primary valve element 41 is cylindrical in form and hollow for the greater part of its length, to thereby define a recess or passage 48 which extends inwardly from the end thereof adjacent the end plate 32. As can be seen in FIG. 2, bore 48 is open to annular groove 40a associated with outlet port 18 and is thus always exposed to return or low pressure.
  • the valve 41 is nestingly received within the follow up valve element 42 and is concentric therewith.
  • One end of the primary valve element 41 is in substantially abutting relationship with the plate 32, the opposite end of the valve element abuttingly engages a trust bearing 44 mounted in the housing 30 and is supported by an end retainer 45.
  • the primary valve element 41 has a splined recess 50 at one end thereof.
  • a control shaft 52 (see FIG.
  • a suitable control elements such as a steerng wheel 54 or the like as shown in FIG. 1.
  • the primary valve element 41 is coupled to the follow up valve element 42 for limited rotary movement in opposite direction with respect to the follow up element 42, and for common rotary movement with the follow up valve element 42.
  • Means for thus coupling the valve elements together comprises a transverse drive pin 56 which extends radially through a pair of diameterically opposed circumferentially extending slots 58 (see FIG. 5) in the primary valve element 41.
  • the opposite ends of the drive pin 56 are snugly received in diameterically opposed aperatures 60 in the follow up valve element 42.
  • a plurality of resilient leaf springs 62 which extend radially through aligned opposed notches 64 and 66 in the primary and follow up valve elements 41 and 42 respectively are provided.
  • a series of grooves and flow passages 41a and 42a are provided in elements 41 and 42 to enable the elements 41 and 42 to control flow of fluid through the controller.
  • the internally toothed member 34 comprises the stator of a meter which measures control fluid to the fluid pressure operated device.
  • the rotor of the meter comprises an externally toothed member 70 having a less number of teeth 72 than the internally toothed member 34.
  • the externally toothed member 70 is adapted to rotate on its own axis and partake of orbital movement about an axis of the member 34.
  • the members 34 and 70 are so arranged that the teeth thereof move into and out of intermeshing engagement and define expanding and contracting fluid chambers 74 during rotary and orbital movement of the member 70.
  • Drive shaft means are provided to drivingly connect follow up valve element 42 for rotation in synchronism with the externally toothed member 70.
  • This driving connection is accomplished by means of a splined bore 76 in member 70 which drivingly engages a splined end 82 of member 80 and pin 56 which is drivingly engaged by a slot 84 in the other end of drive member 80.
  • Drive member 80 passes through the end wall 32 by a clearance bore 32a therein. This clearance is necessary in order to allow end 82 of shaft 80 to partake of orbital movement with member 70.
  • a cylindrical spacer block 77 is provided to fill most of the remaining axial distance of splined bore 76.
  • the splined teeth of bore 76 are thus open to bore 48 and are thus likewise always exposed to the return or low pressure at groove 40a.
  • One advantage of this type of structure in the present invention is that subsequent pressurization of the external surfaces of the metering mechanism will have no effect on the valve mechanism.
  • a retaining ring 102 engaging a groove 104 of the housing 12 and a'seal 106 are provided to maintain the casing 100 in engagement with the housing 12 and to prevent leakage therefrom.
  • the retaining ring 102 is inserted through a slot 107 in the casing 100 and fed along the groove 104 until it reaches the other end of slot 107. 7
  • one end of the splined bore 76 in the externally toothed member 70 is sealed by a plate 108 across the end thereof to prevent pressurized hydraulic fluid from leaking from the expanding and contracting chambers 74 into the splined bore 76 which as previously stated is normally at outlet pressure.
  • the splined bore 76 could be made a blind recess to accomplish the same result.
  • the only resistance to rotation of the steering wheel that the operator can detect at this time is the resistance of springs 62 to relative rotation of the valve members 41, 42.
  • pressurized fluid is acting within the chambers 74 to drive member 80 and follow up valve element 42 to close off the flow.
  • the pressurized fluid in order to rotate the member 70, the pressurized fluid must overcome all frictional forces within the controller as well as the steering load at the wheels 29.
  • relief valve pressure is reached in the system, the operator can only sense the resistance of springs 62 to rotation of the steering wheel.
  • the pump 15 will supply what ever pressure is needed to cause movement of member 70 up to the relief valve pressure.
  • the hydraulic imbalance necessary to reduce the clearance between the externally toothed member 70 of the meter and the surface and provide the aforementioned braking action is created by the difference in end areas of the externally toothed member 70 exposed to pressure.
  • This pressure imbalance results in a predictable axial force being applied to the externally toothed member 70 to cause frictional and sealing engagement with end plate 32 at surface 90.
  • the axial force is defined by the pressure times the area of the splined hole 76 in the center of the externally toothed member 70 of the meter.
  • This force or thrust load creates a certain frictional drag at this interface 90 which results in reducing the travel limit slip rate to near at any system pressure above approximately 500 PSI.
  • This frictional drag is not noticable to the operator except at either end of the steering cylinder stroke.
  • the hydraulic pressure differential across the meter element to overcome this frictional drag is inversely proportional to meter element displacement per revolution.
  • Pressurization of the casing 100 further acts radially upon the external surface of the internally toothed member 34 to prevent radial deformation thereof which further increases the efficiency of this device as a fluid memter by decreasing fluid leakage losses.
  • This version of the high pressure controller design does not require controlled deflection of the end cap 36. Oil is admitted under pressure through a center hole 110 in the end cap 36 to pressurize casing 100. It is felt the pressure admitted into the casing at this point will have less fluctuation with respect to variations of pressure within the meter element.
  • sealing of the bore in the externally toothed member may be eliminated by providing a different fluid flow path for pressurization of the casing 100.
  • FIG. 4 like elements previously designated with respect toFIG. 2 are shown in FIG. 4 by the same numeral with a prime attached.
  • the bore 76' of the externally toothed member 70 may be left open and the plate 108 eliminated. This is because pressurized fluid flow for pressurization of casing 100' is accomplished by an alternate method.
  • Internally toothed member 34 is provided with a notch or groove I communicating between one of the expanding or contracting fluid chambers and the interior of casing 100'.
  • the plate member 36 must be designed to be controllably deflected by working pres sure within the controller.
  • a differential force acts on plate member 36.
  • This differential force controllably deflects plate 36' inwardly to urge both the externally and internally toothed member into substantial sealing engagement with the surfaces 90 and 92' thereby eliminatingor reducing leakages.
  • the radial pressure within the casing 100' would likewise act on the external peripheral surface of internally toothed member 34 to eliminate distortion of externally toothed member 34 caused by pressurization of the chambers 74'.
  • a further advantage of either of the aforementioned embodiments is that if the hydraulic pump 15 should fail, resulting in a loss of control fluid pressure, the frictional braking force acting on member at surfaces and 92' will also be released. The importance of this is that when pump failure occurs, the operator must exert enough force on the steering wheel to'cause the metering portion to pump fluid for steering the vehicle. Thus, elimination of the added friction at surfaces 90 or 90 and 92 makes iteasier for the operator to control the vehicle during such an emergency.
  • said means for applying a braking force to said movable member comprising means for pressure bias-' ing one of the ends of said externally toothed member into frictional engagement with one of said end walls including said movable member having a bore extending axially therethrough, said bore normally being exposed to a pressure which is substantially below the pressure in said fluid chambers, means for sealing said bore to prevent flow therethrough, and a leakage clearance between one of said end surfaces and the adjacent end wall whereby one of said end surfaces may be exposed to pressure in said fluid chambers.
  • said means for pressurizing said casing includes passage means extending from said leakage clearance through one of said end walls to the interior of said casing.
  • a controller for a fluid operated device comprising a housing, a first portion of said housing having an internally toothed member and a pair of axially spaced fixed end walls defining a chamber,
  • valve means disposed in the valve chamber and operable to feed an exhaust pressurized fluid through said expanding and contracting volume chambers upon movement thereof,
  • said drive means connecting said valve means for follow up movement in synchronism with one of the movements of said externally toothed member, said drive means including a shaft having a splined end received in and drivingly engaging the splined bore of said externally toothed member,
  • said externally toothed member having a counterbored recess in one end surface thereof surrounding said splined bore, a plate member disposed in said recess and sealing said splined bore to prevent fluid leakage therethrough and to provide a continuous end surface extending across one end of said externally toothed member, the distance between said fixed end walls of said housing being slightly greater than the width of said externally toothed member to enable one of the end surfaces of said externally toothed member to be entirely exposed to fluid pressure in the expanding and contracting volume chambers, and means in said housing for directly exposing at least a portion of the other end surface of said externally toothed member to a relatively lower fluid pressure to provide a resultant axial force acting on said externally toothed member andurging said externally toothed member into y 12 sealing engagement with one of said end walls.
  • a controller for a fluid pressure operated device comprising a housing, a firstportion of said housing having an internally toothed member and a pair of axially spaced end walls defining a pressurizable metering chamber,
  • an externally toothed member disposed in said chamber for rotational and orbital movement about an axis thereof, the teeth of said members interengaging to form expanding and contracting volume chambers during relative movement therebetween,

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)
  • Fluid-Pressure Circuits (AREA)
US00240418A 1972-04-03 1972-04-03 Controller for fluid operated device Expired - Lifetime US3801239A (en)

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Application Number Priority Date Filing Date Title
US24041872A 1972-04-03 1972-04-03

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US3801239A true US3801239A (en) 1974-04-02

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US00240418A Expired - Lifetime US3801239A (en) 1972-04-03 1972-04-03 Controller for fluid operated device

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US (1) US3801239A (en:Method)
JP (1) JPS4913581A (en:Method)
CA (1) CA978833A (en:Method)
DE (1) DE2316085A1 (en:Method)
FR (1) FR2178995B1 (en:Method)
GB (2) GB1434841A (en:Method)
IT (1) IT982678B (en:Method)

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3960470A (en) * 1975-03-17 1976-06-01 Trw Inc. Hydraulic motor brake
US4116588A (en) * 1976-06-22 1978-09-26 Lucas Industries Limited Fluid pump
US4144712A (en) * 1976-08-19 1979-03-20 Danfoss A/S Hydraulic steering device
US4381905A (en) * 1979-08-28 1983-05-03 Danfoss A/S Hydraulic torque amplifier, particularly for steering devices
US4597725A (en) * 1982-11-24 1986-07-01 Danfoss A/S Rotary piston machine with parallel internal axes
EP0480431A1 (en) * 1990-10-11 1992-04-15 Eaton Corporation Controller with reduced travel limit slip
JP2721920B2 (ja) 1988-10-03 1998-03-04 イートン コーポレーション ステアリングホイールに用いる流体コントローラ
US5762536A (en) * 1996-04-26 1998-06-09 Lam Research Corporation Sensors for a linear polisher
EP0937628A2 (en) 1998-02-23 1999-08-25 Eaton Corporation Hydrostatic power steering system having reduced wheel slip
US6030194A (en) * 1998-01-23 2000-02-29 Eaton Corporation Gerotor motor and improved valve drive and brake assembly therefor
US6071102A (en) * 1997-05-28 2000-06-06 Eaton Corporation Floating seal for sealed star gerotor
US20030217550A1 (en) * 2002-05-27 2003-11-27 Ognibene S.P.A. Hydrostatic power steering device for fast steering
US20040088557A1 (en) * 2002-07-09 2004-05-06 Kaleidescape, A Corporation Secure presentation of media streams in response to encrypted digital content
US20090218161A1 (en) * 2008-02-28 2009-09-03 Eaton Corporation Control Valve Assembly for Electro-Hydraulic Steering System
EP2127998A1 (en) 2008-05-30 2009-12-02 Sauer-Danfoss Holding ApS Hydraulic steering unit
US20110197983A1 (en) * 2008-05-02 2011-08-18 Eaton Corporation Isolation Valve for a Load-Reaction Steering System
US8572104B2 (en) 2003-04-18 2013-10-29 Kaleidescape, Inc. Sales of collections excluding those already purchased
US9506785B2 (en) 2013-03-15 2016-11-29 Rain Bird Corporation Remote flow rate measuring
US10473494B2 (en) 2017-10-24 2019-11-12 Rain Bird Corporation Flow sensor
US10634538B2 (en) 2016-07-13 2020-04-28 Rain Bird Corporation Flow sensor
US11623684B2 (en) * 2020-03-10 2023-04-11 Danfoss Power Solutions Aps Hydraulic steering unit
US11662242B2 (en) 2018-12-31 2023-05-30 Rain Bird Corporation Flow sensor gauge
US11878748B2 (en) 2020-03-10 2024-01-23 Danfoss Power Solutions Aps Fluid controller, in particular as part of a hydraulic steering unit
US12012160B2 (en) 2020-03-10 2024-06-18 Danfoss Power Solutions Aps Fluid controller, in particular as part of a hydraulic steering unit

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3895888A (en) * 1973-10-19 1975-07-22 Trw Inc Hydrostatic control unit
GB2134054B (en) * 1983-01-31 1986-05-29 Mo N Proizv Ob Str Dorozh Mash Hydraulic power steering assembly
DE3504993A1 (de) * 1985-02-14 1986-08-14 Danfoss A/S, Nordborg Steuergeraet fuer hydrostatische hilfskraftlenkeinrichtungen

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2962973A (en) * 1958-07-23 1960-12-06 Vickers Inc Power transmission
US2984215A (en) * 1958-11-25 1961-05-16 Controller for fluid pressure operated devices
US3240158A (en) * 1962-05-08 1966-03-15 Robert W Brundage Hydraulic pump or motor
US3385057A (en) * 1964-08-25 1968-05-28 Trw Inc Hydraulic controller
US3404634A (en) * 1966-09-16 1968-10-08 Eaton Yale & Towne Pump
US3452543A (en) * 1967-11-06 1969-07-01 Trw Inc Hydrostatic device
US3616882A (en) * 1970-02-05 1971-11-02 Trw Inc Hydraulic motor-pump assembly with built-in brake

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2962973A (en) * 1958-07-23 1960-12-06 Vickers Inc Power transmission
US2984215A (en) * 1958-11-25 1961-05-16 Controller for fluid pressure operated devices
US3240158A (en) * 1962-05-08 1966-03-15 Robert W Brundage Hydraulic pump or motor
US3385057A (en) * 1964-08-25 1968-05-28 Trw Inc Hydraulic controller
US3404634A (en) * 1966-09-16 1968-10-08 Eaton Yale & Towne Pump
US3452543A (en) * 1967-11-06 1969-07-01 Trw Inc Hydrostatic device
US3616882A (en) * 1970-02-05 1971-11-02 Trw Inc Hydraulic motor-pump assembly with built-in brake

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3960470A (en) * 1975-03-17 1976-06-01 Trw Inc. Hydraulic motor brake
US4116588A (en) * 1976-06-22 1978-09-26 Lucas Industries Limited Fluid pump
US4144712A (en) * 1976-08-19 1979-03-20 Danfoss A/S Hydraulic steering device
US4381905A (en) * 1979-08-28 1983-05-03 Danfoss A/S Hydraulic torque amplifier, particularly for steering devices
US4597725A (en) * 1982-11-24 1986-07-01 Danfoss A/S Rotary piston machine with parallel internal axes
JP2721920B2 (ja) 1988-10-03 1998-03-04 イートン コーポレーション ステアリングホイールに用いる流体コントローラ
US5136844A (en) * 1990-10-11 1992-08-11 Eaton Corportaion Controller with reduced travel limit slip
EP0480431A1 (en) * 1990-10-11 1992-04-15 Eaton Corporation Controller with reduced travel limit slip
JP3180141B2 (ja) 1990-10-11 2001-06-25 イートン コーポレーション トラベルリミットスリップ低減用コントローラ
US5762536A (en) * 1996-04-26 1998-06-09 Lam Research Corporation Sensors for a linear polisher
US6071102A (en) * 1997-05-28 2000-06-06 Eaton Corporation Floating seal for sealed star gerotor
US6030194A (en) * 1998-01-23 2000-02-29 Eaton Corporation Gerotor motor and improved valve drive and brake assembly therefor
EP0937628A2 (en) 1998-02-23 1999-08-25 Eaton Corporation Hydrostatic power steering system having reduced wheel slip
US5960694A (en) * 1998-02-23 1999-10-05 Eaton Corporation Hydrostatic power steering system having reduced wheel slip
US6863147B2 (en) * 2002-05-27 2005-03-08 Ognibene S.P.A. Hydrostatic power steering device for fast steering
US20030217550A1 (en) * 2002-05-27 2003-11-27 Ognibene S.P.A. Hydrostatic power steering device for fast steering
US7702101B2 (en) * 2002-07-09 2010-04-20 Kaleidescape, Inc. Secure presentation of media streams in response to encrypted digital content
US20040088557A1 (en) * 2002-07-09 2004-05-06 Kaleidescape, A Corporation Secure presentation of media streams in response to encrypted digital content
US8572104B2 (en) 2003-04-18 2013-10-29 Kaleidescape, Inc. Sales of collections excluding those already purchased
US7984785B2 (en) 2008-02-28 2011-07-26 Eaton Corporation Control valve assembly for electro-hydraulic steering system
US20090218161A1 (en) * 2008-02-28 2009-09-03 Eaton Corporation Control Valve Assembly for Electro-Hydraulic Steering System
US8651225B2 (en) 2008-02-28 2014-02-18 Eaton Corporation Control valve assembly for electro-hydraulic steering system
US20110197983A1 (en) * 2008-05-02 2011-08-18 Eaton Corporation Isolation Valve for a Load-Reaction Steering System
US8272471B2 (en) 2008-05-02 2012-09-25 Eaton Corporation Isolation valve for a load-reaction steering system
EP2127998A1 (en) 2008-05-30 2009-12-02 Sauer-Danfoss Holding ApS Hydraulic steering unit
US9506785B2 (en) 2013-03-15 2016-11-29 Rain Bird Corporation Remote flow rate measuring
US10634538B2 (en) 2016-07-13 2020-04-28 Rain Bird Corporation Flow sensor
US10473494B2 (en) 2017-10-24 2019-11-12 Rain Bird Corporation Flow sensor
US11662242B2 (en) 2018-12-31 2023-05-30 Rain Bird Corporation Flow sensor gauge
US11623684B2 (en) * 2020-03-10 2023-04-11 Danfoss Power Solutions Aps Hydraulic steering unit
US11878748B2 (en) 2020-03-10 2024-01-23 Danfoss Power Solutions Aps Fluid controller, in particular as part of a hydraulic steering unit
US12012160B2 (en) 2020-03-10 2024-06-18 Danfoss Power Solutions Aps Fluid controller, in particular as part of a hydraulic steering unit

Also Published As

Publication number Publication date
FR2178995A1 (en:Method) 1973-11-16
CA978833A (en) 1975-12-02
GB1434841A (en) 1976-05-05
DE2316085A1 (de) 1973-10-11
FR2178995B1 (en:Method) 1977-04-29
GB1434842A (en) 1976-05-05
IT982678B (it) 1974-10-21
JPS4913581A (en:Method) 1974-02-06

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