US3347043A - Master cylinder construction affording automatic re-phasing of master and slave cylinders - Google Patents

Master cylinder construction affording automatic re-phasing of master and slave cylinders Download PDF

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Publication number
US3347043A
US3347043A US509113A US50911365A US3347043A US 3347043 A US3347043 A US 3347043A US 509113 A US509113 A US 509113A US 50911365 A US50911365 A US 50911365A US 3347043 A US3347043 A US 3347043A
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United States
Prior art keywords
cylinder
piston
chamber
master
fluid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US509113A
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English (en)
Inventor
Freese Evans Glenn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cessna Aircraft Co
Original Assignee
Cessna Aircraft Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cessna Aircraft Co filed Critical Cessna Aircraft Co
Priority to US509113A priority Critical patent/US3347043A/en
Priority to GB16044/66A priority patent/GB1082140A/en
Priority to SE5177/66A priority patent/SE324106B/xx
Priority to DE19661550709 priority patent/DE1550709A1/de
Application granted granted Critical
Publication of US3347043A publication Critical patent/US3347043A/en
Priority to US05/504,179 priority patent/USRE28695E/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/22—Synchronisation of the movement of two or more servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/003—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors with multiple outputs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/005—With rotary or crank input
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/06—Details
    • F15B7/08—Input units; Master units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/06—Details
    • F15B7/10—Compensation of the liquid content in a system

Definitions

  • a master cylinder construction embodying my inven tion is illustrated and described herein associated with a single slave cylinder.
  • both master and slave cylinders are simultaneously performing useful work at widely separated locations, it is often required that the pistons and rods of the two cylinders start their movement simultaneously, travel at substantially the same velocity, travel the same distance, and reach the ends of their respective strokes at substantially the same time. This is true, for instance, when two such cylinders are connected to raise and lower the respective opposite ends of the reel on a combine or other harvester.
  • Such coordinated action of the cylinders is required in order to maintain the elongated reel in a level position throughout the raising and lowering operation.
  • the difliculty of maintaining such coordinated action over an extended period of weeks is primarily due to uneven wear of the working parts of the two working cylinders, particularly the hydraulic fluid seals. Seal wear causes leakage, and due to this leakage the piston and rod of one cylinder may not complete its travel to the full end of its permitted stroke in either direction, resulting in a progressive shortening of the length of its stroke. In other words the pistons and rods of the two cylinders get out of phase.
  • Another important object of the invention is to provide a master cylinder construction which automatically provides a relief against over pressurization of one cylinder due to the fact that the piston of that cylinder reaches the end of its permitted stroke prior to the time the piston of an associated cylinder reaches the end of its permitted stroke.
  • Another object is to provide a master cylinder construction which accomplishes the above described results without the use of poppet valves, manual valves, etc., which are commonly used to accomplish re-phasing of associated working cylinders, whether they are connected in series or in parallel.
  • An additional object of the invention is to provide a double acting working cylinder construction which provides relief against internal over pressurization of the cylinder at both ends of the piston stroke in case the control valve directing pressure fluid to either end of the cylinder is not closed just prior to or at approximately the instant the piston reaches the end of its stroke in either direction.
  • FIG. 1 is a central longitudinal sectional view through a hydraulic working cylinder embodying my invention, shown connected in series to an associated hydraulic slave cylinder, the hydraulic system for actuating both cylinders being shown schematically, the respective pistons and rods of both cylinders being shown at the inner ends of their permitted strokes;
  • FIG. 2 is a view similar to FIG. 1, with the respective pistons and rods of both cylinders being shown at the outer ends of their permitted strokes;
  • FIG. 3 is a fragmentary view of a portion of the cylinder shown in the lower part of FIG. 2, and includes optional check valves which are not included in the other drawing figures, yet which constitute a part of my invention.
  • a cylinder construction which embodies my invention is shown in the lower portion of FIG. 1, and is designated as a whole by the numeral 10.
  • cylinder 10 is shown connected in series to a slave cylinder 11 by means-of a conduit 12.
  • Cylinder 10 will be referred to herein as a master cylinder, although it should be understood that this cylinder may be used in any hydraulic system as a double acting working cylinder, completely disassociated from any slave cylinder.
  • master cylinder 10 includes a barrel 13 having a fixed head 14 at one of its ends and a removable piston rod bearing 15 at its other end.
  • Bearing 15 carries seals 16 and 17.
  • the head 14 and the inner end 18 of bearing 15 serve as travel limit stops for a piston 19.
  • Barrel 13 is provided with relatively large longitudinally spaced ports 20 and 21, and a pair of respectively associated fluid escape orifices 22 and 23. Port 20 and orifice 22 both communicate with a conduit attachment fitting 24, while port 21 and orifice 23 both communicate with a similar conduit fitting 25.
  • Piston 19 carries an integral stop 26, and is connected to a reciprocable rod 27. Piston 19 is provided with a central annular groove 28 which seats an annular wall seal 29, adjacent annular lands 30 and 31 which are of a diameter to fit the barrel wall snugly, grooves 32 and 33, and outside lands 34 and 35. Piston 19, of course, divides the interior of barrel 13 into two pressure fluid chambers 36 and 37.
  • port 21 is located outside seal 29 and openly communicates with chamber 37.
  • escape orifice 23 is located inside seal 29. If fluid pressure in chamber 36 is higher than in fitting 25 and chamber 37, fluid can leak past land 34, through orifice 23 and into fitting 25. Leakage of fluid through orifice 23 in the opposite direction, due to the existence of a higher pressure in fitting 25 than in chamber 36, is inconsequential.
  • master cylinder fitting 25 is connected by conduit 12 to a port 38 in a wall of single acting slave cylinder 11.
  • Port 33 communicates with a pressure chamber 39, within which a combination piston and rod is reciprocable
  • the chambers 37 and 39 have equal volume capacities, regardless of the permitted length of stroke of the piston rods 27 and 40.
  • a piston rod seal 41 normally preventsleakage from slave cylinder chamber 39 as the rod reciprocates.
  • a snap ring 42 is seated in an annular groove near the inner end of rod 40, and serves as a stop to limit outward movement of the rod in its cylinder. Inward movement of rod 40 is limited by contact of the inner end of the rod with an inwardly projecting abutment 43, integral with the cylinder end wall.
  • control valve 46 can be adjusted to its FIG. 2 condition, which connects master chamber 36 to a system reservoir 49, and allows both pistons to simultaneously start their inward travel under the influence of their respective loads.
  • slave cylinder piston 40 reaches the inner end of its stroke before master piston 19 has completed its stroke, and a void is created in chamber 37 as piston 19 continues to the end of its stroke, that void is filled through escape orifice 22 by pressure fluid from the pump before either piston again starts its outward travel during the next cycle.
  • the pistons and rods of the two cylinders are thus re-phased at each of the ends of their respective strokes.
  • FIG. 3 Construction 0perationFl G. 3
  • the washer type check valves 50 and 51 are useful in reventing uneven extension or retraction of the two piston rods 27 and 40 in case .rod 27 is loaded much more heavily than rod 40.
  • check valve 50 prevents pressure fluid from traveling through escape orifice 22, chamber 37, and to slave chamber 39, and moving pistonv 40 outward while master piston 27 remains stationary under its heavier load.
  • checkv valve 51 prevents fluid from being forced from slave cylinder chamber 39 through escape orifice 23 and conduit 44 to reservoir. Rod 40 is thus prevented from moving inward in its cylinder under its greater load, while the pressure build upin master chamber 36 temporarily prevents rod 27 from moving inward under its lighter load. Uneven retraction or extension of the unequally loaded piston rods is thus prevented.
  • a hydraulic actuator assembly comprising:
  • a piston having limited reciprocable movement within the cylinder, and dividing the cylinder into first and second chambers;
  • a first fluid escape orifice through a wall of the cylinder located to afford restricted exterior communication with the second chamber only when the piston is at one end of its permitted stroke;
  • a second fluid escape orifice through a wall of the cylinder located to afford restricted exterior communication with the first chamber only when the piston is at the other end of its permitted stroke.
  • fluid conducting means affording communication exterior of the cylinder between each of said ports and the respectively adjacent fluid, escape orifice.
  • a hydraulic actuator which includes an elongated cylinder and a piston having limited reciprocatory move ment therein, and which divides the cylinder into first and second chambers, said cylinder including separate means for conducting fluid into and from the respective chambers, the improvement in such an actuator which Comprises:
  • a second fluid escape orifice through a wall of the cylinder located to aflord restricted egress of fluid from said first chamber when the piston has moved to a position to reduce said second chamber to minimum volume capacity.
  • a hydraulic actuator assembly comprising:
  • first and second longitudinally spaced fluid escape orifices through the cylinder wall communicating respectively with the first and second inlet and outlet fittings, one orifice adjacent each of said ports, the longitudinal spacing between the orifices being less than the longitudinal spacing between said ports, and the fittings, ports and orifices being in substantial longitudinal alignment along the cylinder wall;
  • annular seal or packing carried by the piston for sealing between the piston and the internal wall of the cylinder, and for thus dividing the cylinder into first and second fluid pressure chambers

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
US509113A 1965-11-22 1965-11-22 Master cylinder construction affording automatic re-phasing of master and slave cylinders Expired - Lifetime US3347043A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US509113A US3347043A (en) 1965-11-22 1965-11-22 Master cylinder construction affording automatic re-phasing of master and slave cylinders
GB16044/66A GB1082140A (en) 1965-11-22 1966-04-12 Improved hydraulic actuator
SE5177/66A SE324106B (enrdf_load_stackoverflow) 1965-11-22 1966-04-15
DE19661550709 DE1550709A1 (de) 1965-11-22 1966-09-29 Hydraulischer Antrieb
US05/504,179 USRE28695E (en) 1965-11-22 1974-09-09 Master cylinder construction affording automatic re-phasing of master and slavecylinders

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US509113A US3347043A (en) 1965-11-22 1965-11-22 Master cylinder construction affording automatic re-phasing of master and slave cylinders

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/504,179 Reissue USRE28695E (en) 1965-11-22 1974-09-09 Master cylinder construction affording automatic re-phasing of master and slavecylinders

Publications (1)

Publication Number Publication Date
US3347043A true US3347043A (en) 1967-10-17

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US509113A Expired - Lifetime US3347043A (en) 1965-11-22 1965-11-22 Master cylinder construction affording automatic re-phasing of master and slave cylinders

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US (1) US3347043A (enrdf_load_stackoverflow)
DE (1) DE1550709A1 (enrdf_load_stackoverflow)
GB (1) GB1082140A (enrdf_load_stackoverflow)
SE (1) SE324106B (enrdf_load_stackoverflow)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3462986A (en) * 1967-10-26 1969-08-26 Rockwell Standard Co Brake actuator
US3475904A (en) * 1967-06-26 1969-11-04 Penn Controls Heat motor utilizing expansible fluid for driving a piston
US3650182A (en) * 1969-09-17 1972-03-21 Cessna Aircraft Co Closure for fluid pressure vessel
US3665816A (en) * 1970-11-10 1972-05-30 James C Caudle Power cylinder construction
US3812942A (en) * 1971-06-12 1974-05-28 Bosch Gmbh Robert Hydraulic system
US3832852A (en) * 1972-10-20 1974-09-03 Cessna Aircraft Co Construction affording automatic synchronizing of master and slave fluid power cylinders
USRE28695E (en) * 1965-11-22 1976-01-27 The Cessna Aircraft Company Master cylinder construction affording automatic re-phasing of master and slavecylinders
US4164122A (en) * 1977-09-19 1979-08-14 International Harvester Company Cylinder construction affording automatic re-phasing of master and slave cylinders
US20020170785A1 (en) * 2001-04-27 2002-11-21 Stockmann Thomas H. Hydraulic platform lift incorporating positive displacement valve, and positive displacement valve for hydraulic platform lift
US20080053351A1 (en) * 2006-08-31 2008-03-06 Bettin Leonard A Front Fold Planter Lift and Fold Hydraulic Control System
US11131330B1 (en) * 2020-03-30 2021-09-28 Caterpillar Inc. Crimp retained hydraulic cylinder head and cap

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4208980A1 (de) * 1992-03-20 1993-09-23 Rexroth Mannesmann Gmbh Hydraulische antriebsvorrichtung mit einem zylinder

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2312337A (en) * 1940-01-29 1943-03-02 Leigh E Hughes Hydraulic well pump
US2539720A (en) * 1948-09-10 1951-01-30 John C Bender Fluid motor with valve disk and cushioning means
US2591793A (en) * 1945-11-28 1952-04-08 Dubois Maurice Odile Device for adjusting the return travel of fluid actuated means
US2766590A (en) * 1951-10-18 1956-10-16 Ford Motor Co Fluid pressure system for motivating a reciprocating load
US2882685A (en) * 1956-07-02 1959-04-21 Gleason Works Hydraulic motion transmitting system
US2997849A (en) * 1959-05-28 1961-08-29 Outboard Marine Corp Self-purging hydraulic control device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2312337A (en) * 1940-01-29 1943-03-02 Leigh E Hughes Hydraulic well pump
US2591793A (en) * 1945-11-28 1952-04-08 Dubois Maurice Odile Device for adjusting the return travel of fluid actuated means
US2539720A (en) * 1948-09-10 1951-01-30 John C Bender Fluid motor with valve disk and cushioning means
US2766590A (en) * 1951-10-18 1956-10-16 Ford Motor Co Fluid pressure system for motivating a reciprocating load
US2882685A (en) * 1956-07-02 1959-04-21 Gleason Works Hydraulic motion transmitting system
US2997849A (en) * 1959-05-28 1961-08-29 Outboard Marine Corp Self-purging hydraulic control device

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE28695E (en) * 1965-11-22 1976-01-27 The Cessna Aircraft Company Master cylinder construction affording automatic re-phasing of master and slavecylinders
US3475904A (en) * 1967-06-26 1969-11-04 Penn Controls Heat motor utilizing expansible fluid for driving a piston
US3462986A (en) * 1967-10-26 1969-08-26 Rockwell Standard Co Brake actuator
US3650182A (en) * 1969-09-17 1972-03-21 Cessna Aircraft Co Closure for fluid pressure vessel
US3665816A (en) * 1970-11-10 1972-05-30 James C Caudle Power cylinder construction
US3812942A (en) * 1971-06-12 1974-05-28 Bosch Gmbh Robert Hydraulic system
US3832852A (en) * 1972-10-20 1974-09-03 Cessna Aircraft Co Construction affording automatic synchronizing of master and slave fluid power cylinders
US4164122A (en) * 1977-09-19 1979-08-14 International Harvester Company Cylinder construction affording automatic re-phasing of master and slave cylinders
US20020170785A1 (en) * 2001-04-27 2002-11-21 Stockmann Thomas H. Hydraulic platform lift incorporating positive displacement valve, and positive displacement valve for hydraulic platform lift
US7299897B2 (en) 2001-04-27 2007-11-27 Saf-Holland Equipment Limited Hydraulic platform lift incorporating positive displacement valve, and positive displacement valve for hydraulic platform lift
US20080053351A1 (en) * 2006-08-31 2008-03-06 Bettin Leonard A Front Fold Planter Lift and Fold Hydraulic Control System
US7469648B2 (en) 2006-08-31 2008-12-30 Cnh America, Llc Front fold planter lift and fold hydraulic control system
US11131330B1 (en) * 2020-03-30 2021-09-28 Caterpillar Inc. Crimp retained hydraulic cylinder head and cap

Also Published As

Publication number Publication date
DE1550709A1 (de) 1970-09-17
GB1082140A (en) 1967-09-06
SE324106B (enrdf_load_stackoverflow) 1970-05-19

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