US3787019A - Supporting element of adjustable length - Google Patents

Supporting element of adjustable length Download PDF

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Publication number
US3787019A
US3787019A US00240646A US3787019DA US3787019A US 3787019 A US3787019 A US 3787019A US 00240646 A US00240646 A US 00240646A US 3787019D A US3787019D A US 3787019DA US 3787019 A US3787019 A US 3787019A
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United States
Prior art keywords
chamber
plunger
recess
axially
liquid
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
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US00240646A
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English (en)
Inventor
H Freitag
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.)
Stabilus Industrie und Handels GmbH
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Stabilus Industrie und Handels GmbH
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Publication of US3787019A publication Critical patent/US3787019A/en
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    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
    • A47C3/20—Chairs or stools with vertically-adjustable seats
    • A47C3/30—Chairs or stools with vertically-adjustable seats with vertically-acting fluid cylinder
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47B—TABLES; DESKS; OFFICE FURNITURE; CABINETS; DRAWERS; GENERAL DETAILS OF FURNITURE
    • A47B9/00—Tables with tops of variable height
    • A47B9/10—Tables with tops of variable height with vertically-acting fluid cylinder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
    • B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
    • B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
    • B60N2/04—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the whole seat being movable
    • B60N2/16—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the whole seat being movable height-adjustable
    • B60N2/1635—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the whole seat being movable height-adjustable characterised by the drive mechanism
    • B60N2/1665—Hydraulic or pneumatic actuation

Definitions

  • ABSTRACT A normally upright, telescopically adjustable, supporting element, such as a leg for a stool, has a cylinder whose cavity is axially divided into two chambers by a partition.
  • the lower chamber is liquid-filled, the upper chamber contains liquid under the pressure of a gas cushion, and the two chambers may be connected by a valve in the partition.
  • the position of a plunger axially projecting from the lower chamber is generally determined by the amount of non-compressible liquid in the lower chamber, but limited axial movement is made possible by a gas cell partly bounded by the plunger and otherwise by a sealing member separating the gas in the cell from the liquid in the lower chamber.
  • This invention relates to telescopically adjustable supporting elements, and particularly to improvements in a supporting element whose principal elements are a cylinder partly filled with liquid and a plunger axially projecting from the cylinder.
  • a basic object of this invention is the provision of a supporting element of variable length which resiliently resists axial stress with a force independent of the effective length of the element, and thus permits the length of the element under a fixed load to be set with great precision prior to loading.
  • Another object is the provision of such a resilient support which is of simple and rugged construction and thus capable of long, reliable service while permitting manufacture at low cost.
  • the invention provides a supporting element in which the cavity of a cylinder is axially divided into two chambers by a fixed partition.
  • a valve operatively interposed between'the chambers may be moved between an open position and a closed position by an operating mechanism accessible outside the cylinder cavity.
  • a first one of the chambers contains an amount of gas under super-atmospheric pressure and a first body of liquid in pressure-transmitting relationship.
  • a plunger is axially movable in the cylinder and has respective terminal portions in the second chamber and outside the cylinder. Yieldably resilient means bias the plunger outward of the cylinder. Although a second body of liquid fills the remainder of the second chamber and communicates with the first body only in the open position of the valve, the yieldably resilient means permit limited movement of the plunger inward of the second chamber when the valve is in its closed position.
  • FlG. 1 shows an adjustable stool leg of the invention in fragmentary elevational section
  • FlGS. 2 and 3 show modifications of the device of FIG. 1 in respective corresponding views.
  • the radial top wall of the cylinder 12 is formed by a fixed plug 114 projecting outward of the cylinder and externally threaded over much of its projecting length for assembly with the seat of thestool by means of a suitable connector, not shown.
  • a rod 13 passes axially through a central bore in the plug 14 and carries a seal ing ring 23 in the bore.
  • a transverse bar 13a permits the end portion of the rod 13,accessible outside the cavity of the cylinder 12, to be moved axially.
  • the cylinder cavity is divided axially into an upper chamber and a lower chamber by a partition 10 held in a fixed axial position between two internal shoulders of the cylinder wall corresponding to rolled, circumferential grooves 18 on the outer cylinder face.
  • the partition 10 is sealed to the cylinder 12 by a ring 19.
  • a central bore in the partition 10 receives the lower end portion of the rod 13 with ample clearance, but a resilient ring 20 partly retained in a circumferential groove of the rod forms a valve which closes the conduit in the partition 10 when in the illustrated position and seals the two chambers of the cylinder cavity from each other.
  • the lower cylinder chamber is provided with a piston 8 which is axially movable and divides the chamber into two compartments 5, 9 communicating through throttling passages 15 in the piston 8 and as completely filled with another body of liquid as is possible. Any gas that may be present initially in the lower cylinder chamber ultimately makes its way to the gas 22 in the upper chamber.
  • the piston 8 is axially fastened on the tubular upper end of the plunger 11 between two integral shoulders of the latter.
  • the cylindrical, blind bore of the plunger 1 is sealed from the liquid in the upper compartment 9 of the lower cylinder chamber by a cylindrical plug 7 carrying a resilient sealing ring 17 to retain a body of highly compressed gas in the cell 6 axially bounded in the plunger bore by the plug '7 and the closed end of the bore.
  • the plug 7 is normally held by the gas in the cell 6 against a spring washer 16 which prevents ejection of the plug from the plunger 1.
  • the length of the illustrated support element when free from an applied load is precisely determined by the combined amount of incompressible liquid in the compartments 5,9.
  • the plug 7 abuts against the washer l6, and the plunger 1 cannot be pulled outward of the cylinder by a force not capable of causing cavitation in the liquid below the partition 10..
  • the latter amount controls the overall length of the element. if this length is to be changed, the valve ring 20 is moved to its open position by means of its operating rod 13, and liquid is permitted to flow downward through the partition 10 under the pressure of the gas 22, or is forced to flow upward through the partition under a compressive, external force applied to the cylinder 12 and the plunger 1. Too sudden a length change is prevented by the reduced flow section of the throttling passages 15.
  • the piston 8 also guides the plunger 1 and the plug 7 on the plunger during their joint axial movement.
  • the valve ring is returned manually to the illustrated, closed position as soon as the element has reached the desired increased or decreased length.
  • the pressures of the gas 22 in the first cylinder chamher and of the gas in the cell 6 are chosen so that the plug 7 remains in the illustrated position of abutment against the spring washer 16 when the valve ring 20 is in its open position, that is, the force exerted by the gas in the cell 6 on the plunger 1 and tending to shift the plunger outward of the cylinder 12 must always be greater than the corresponding force of the gas 22 transmitted to the plunger by-the liqud ll. Under these conditions, the volume of the cell 6 remains constant at its maximum value while the valve in the partition 10 is open during adjustment of element length, and the adjusted length is not changed after closing of the valve by volume changes of the cell 6.
  • the modified stool leg shown in H6. 2 is identical with that described above in detail with reference to FIG. 1 except as specifically stated hereinbelow.
  • a coaxial split ring 29 partly received in a groove of the plunger 1' abuts against a shock absorbing ring 27 on the piston 8' in the illustrated relative position of piston and plunger, and a shock absorbing pad 28 on the bottom of the cupshaped container 24 in the cell 6' reduces noise when the plunger 1' moves to the non-illustrated terminal position of its stroke relative to the container 24.
  • the conduit in the partition 10 is opened, and the plunger 1' is pushed inward of the cylinder 12 at a rate controlled by the resistance of the passages 15 to downward flow of liquid.
  • the gas 22 is compressed to admit additional liquid to the upper chamber Of the cylinder 12, but no significant displacement of the plunger 1' relative to the container 24 can occur, and the unloaded length of the element after the closing of the valve in the partition 16 is the same as the length was at the moment of valve closing under an applied load.
  • the supporting element illustrated in H6. 3 is identical with that described with reference to FIG. 2 except for the devices in the upper end of the cylinder 12.
  • the partition 10' and the externally threaded plug 14", not significantly different from the partition it) and the plug 14, are integrally connected by a coaxial tube 30.
  • Several radial bores 31 in the tube 30 adjacent the partition 10' connect the portion of the upper cylinder chamber filled with liquid ill to an annular chamber 33 about a reduced portion 34 of the valve operating rod 13".
  • the chamber in the illustrated position of the rod, the chamber is axially bounded by conically flaring parts 32, 32a of the rod and sealed by resilient rings 23, 2% closely adjacent the conical parts, the ring acting as a valve which, in the illustrated position, blocks the flow of liquid between the two cylinder chambers through the bores 31, only one being seen in the drawing, and the annular chamber 33.
  • FIG. 3 operates in the same manner as described above with reference to FIG. 2.
  • a supporting element of adjustable length comprising, in combination:
  • a cylinder member having an axis and defining a sealed cavity therein;
  • valve means operatively interposed between said chambers and movable between respective open and closed positions in which said valve means connects said chambers and seals said chambers from each other;
  • valve operating means accessible outside said cavity for moving said valve means between said positions thereof;
  • said plunger member having respective axially terminal portions in said second chamber and outside said cylinder;
  • yieldably resilient means in said second chamber opposing movement of said plunger member inward of said second chamber with a second force substantially greater than said first force when said valve means is in the closed position thereof.
  • said yieldably resilient means include a sealing member movable relative to said plunger member and defining therewith a cell, and a body of gas sealed from said second body of liquid in said cell by said sealing member.
  • sealing member is formed with a recess therein, the axi-. ally terminal portion of said plunger member being received in said recess for movement inward and outward of said recess, a portion of said recess constituting said cell.
  • said guide means include a piston member axially movable in said second chamber and dividing the same into two compartments, said piston member being formed with a throttling passage connecting said compartments,said plunger member engaging said piston member.
  • sealing member is fixedly mounted on said piston member and formed with a recess therein, the axially terminal portion of said plunger member being received in said recess for movement inward and outward of said recess, a portion of said recess constituting said cell.
  • valve operating means include a rod member elongated in the direction of said axis and having respective longitudinal portions outside said cavity, in said first chamber, and in said conduit, sealing means interposed between said rod member and said cylinder member permitting axial movement of said rod member inward and outward of said cavity, said valve means including a valve member mounted on said rod member for movement therewith and sealing said conduit in the closed position of said valve means.

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  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
  • Chairs Characterized By Structure (AREA)
  • Tables And Desks Characterized By Structural Shape (AREA)
  • Actuator (AREA)
US00240646A 1971-04-06 1972-04-03 Supporting element of adjustable length Expired - Lifetime US3787019A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19712116699 DE2116699A1 (de) 1971-04-06 1971-04-06 Blockierbares Hubaggregat mit kol benstangenferner Betätigung

Publications (1)

Publication Number Publication Date
US3787019A true US3787019A (en) 1974-01-22

Family

ID=5803988

Family Applications (1)

Application Number Title Priority Date Filing Date
US00240646A Expired - Lifetime US3787019A (en) 1971-04-06 1972-04-03 Supporting element of adjustable length

Country Status (5)

Country Link
US (1) US3787019A (enrdf_load_stackoverflow)
JP (1) JPS5521209B1 (enrdf_load_stackoverflow)
DE (1) DE2116699A1 (enrdf_load_stackoverflow)
FR (1) FR2132491B1 (enrdf_load_stackoverflow)
GB (1) GB1335323A (enrdf_load_stackoverflow)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2546057A1 (de) * 1974-10-14 1976-04-22 Tokico Ltd Verriegelungsvorrichtung in einer gasfeder
US4050684A (en) * 1976-07-19 1977-09-27 Sanders Franklin C Velocity sensitive dual rate shock strut
US4063723A (en) * 1975-09-22 1977-12-20 Fritzmeier Ag Spline element for seat in a vehicle
US4106596A (en) * 1975-11-17 1978-08-15 Firma August Bilstein Hydropneumatic single tube shock absorber, in particular steering shock absorber
US4124202A (en) * 1976-05-28 1978-11-07 Tokico Ltd. Gas spring
US4764083A (en) * 1985-08-19 1988-08-16 Hitachi, Ltd. Discharge ring supporting structure of adjustable-blade axial-flow turbine
US4817898A (en) * 1986-05-15 1989-04-04 Giroflex Entwicklungs Ag Adjusting device, particularly for adjustable chairs
US5024301A (en) * 1990-05-23 1991-06-18 Ford Motor Company Hydraulic rebound stop assembly for a shock absorber
US5133529A (en) * 1989-08-22 1992-07-28 Kayaba Kogyo Kabushiki Kaisha Seat damper
US5195619A (en) * 1991-09-03 1993-03-23 General Motors Corporation Internal accumulator for a hydraulic damper
US5294086A (en) * 1989-03-13 1994-03-15 Lucio Fantini Adjustable oleopneumatic amortized support column, for chairs and armchairs
US5706845A (en) * 1997-02-14 1998-01-13 Beyar; George Walker adapter
GB2371485A (en) * 2001-01-24 2002-07-31 Neumann Benny William Resilient telescopic walking stick
US6471178B1 (en) * 1997-05-21 2002-10-29 Cabex Ag Device for adjusting the length of a support and method for producing same
US20050001132A1 (en) * 2003-06-13 2005-01-06 Machael Jay R. Height adjustment cylinder with non-tapered threaded region
US20100107867A1 (en) * 2008-10-30 2010-05-06 Hyundai Motor Company Lifter for lid of motor vehicle
US20120048482A1 (en) * 2009-04-30 2012-03-01 Libervit Device for blocking a passage
CN105156570A (zh) * 2015-07-20 2015-12-16 常州大学 双杆变节流孔无源单控变阻尼磁流变阻尼器
US10005509B2 (en) * 2016-11-04 2018-06-26 Taiwan Hodaka Industrial Co., Ltd. Bicycle seat cushion lifting and adjusting device
US10202158B2 (en) * 2016-08-31 2019-02-12 Giant Manufacturing Co., Ltd. Adjustable seat tube structure and bicycle

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2441510A1 (fr) * 1978-11-20 1980-06-13 Allinquant J G Dispositif de montage de sieges, notamment de sieges de voitures ou autres vehicules
DE2948081A1 (de) * 1979-11-29 1981-06-04 Stabilus Gmbh, 5400 Koblenz Laengeneinstellbares federelement
DE3410309A1 (de) * 1984-03-21 1985-10-03 Stabilus Gmbh, 5400 Koblenz Kraftveraenderbare gasfeder
DE10302870B3 (de) * 2003-01-28 2004-08-05 Stabilus Gmbh Verstellvorrichtung

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2042443A (en) * 1935-02-04 1936-05-26 Eastman Kodak Co Adjustable supporting pillar or the like
FR1016105A (fr) * 1950-04-07 1952-11-03 Pilier extensible à commande hydraulique, utilisable comme étançon de mine susceptible de supporter de fortes pressions
GB686723A (en) * 1947-05-31 1953-01-28 Christian Marie Lucien Louis B Improvements relating to direct-acting hydraulic shock absorbers for the suspensions of road vehicles
FR1163647A (fr) * 1956-01-28 1958-09-29 Boge Gmbh Amortisseur télescopique monotubulaire hydropneumatique
DE1144544B (de) * 1960-09-21 1963-02-28 Albert Dillenburger Hydropneumatischer Einrohrstossdaempfer, insbesondere fuer Kraftfahrzeuge
US3142156A (en) * 1960-12-22 1964-07-28 Dowty Mining Equipment Ltd Telescopic hydraulic props
US3163262A (en) * 1961-11-07 1964-12-29 Allinquant Fernand Stanislas Hydraulic telescopic shock absorbers
US3388883A (en) * 1965-02-25 1968-06-18 Fichtel & Sachs Ag Hydropneumatic support column of adjustable length
US3656593A (en) * 1968-12-03 1972-04-18 Fritz Bauer Continuously adjustable lifting devices

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2042443A (en) * 1935-02-04 1936-05-26 Eastman Kodak Co Adjustable supporting pillar or the like
GB686723A (en) * 1947-05-31 1953-01-28 Christian Marie Lucien Louis B Improvements relating to direct-acting hydraulic shock absorbers for the suspensions of road vehicles
FR1016105A (fr) * 1950-04-07 1952-11-03 Pilier extensible à commande hydraulique, utilisable comme étançon de mine susceptible de supporter de fortes pressions
FR1163647A (fr) * 1956-01-28 1958-09-29 Boge Gmbh Amortisseur télescopique monotubulaire hydropneumatique
DE1144544B (de) * 1960-09-21 1963-02-28 Albert Dillenburger Hydropneumatischer Einrohrstossdaempfer, insbesondere fuer Kraftfahrzeuge
US3142156A (en) * 1960-12-22 1964-07-28 Dowty Mining Equipment Ltd Telescopic hydraulic props
US3163262A (en) * 1961-11-07 1964-12-29 Allinquant Fernand Stanislas Hydraulic telescopic shock absorbers
US3388883A (en) * 1965-02-25 1968-06-18 Fichtel & Sachs Ag Hydropneumatic support column of adjustable length
US3656593A (en) * 1968-12-03 1972-04-18 Fritz Bauer Continuously adjustable lifting devices

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2546057A1 (de) * 1974-10-14 1976-04-22 Tokico Ltd Verriegelungsvorrichtung in einer gasfeder
US4063723A (en) * 1975-09-22 1977-12-20 Fritzmeier Ag Spline element for seat in a vehicle
US4106596A (en) * 1975-11-17 1978-08-15 Firma August Bilstein Hydropneumatic single tube shock absorber, in particular steering shock absorber
US4124202A (en) * 1976-05-28 1978-11-07 Tokico Ltd. Gas spring
US4050684A (en) * 1976-07-19 1977-09-27 Sanders Franklin C Velocity sensitive dual rate shock strut
US4764083A (en) * 1985-08-19 1988-08-16 Hitachi, Ltd. Discharge ring supporting structure of adjustable-blade axial-flow turbine
US4817898A (en) * 1986-05-15 1989-04-04 Giroflex Entwicklungs Ag Adjusting device, particularly for adjustable chairs
US5294086A (en) * 1989-03-13 1994-03-15 Lucio Fantini Adjustable oleopneumatic amortized support column, for chairs and armchairs
US5133529A (en) * 1989-08-22 1992-07-28 Kayaba Kogyo Kabushiki Kaisha Seat damper
US5024301A (en) * 1990-05-23 1991-06-18 Ford Motor Company Hydraulic rebound stop assembly for a shock absorber
US5195619A (en) * 1991-09-03 1993-03-23 General Motors Corporation Internal accumulator for a hydraulic damper
US5706845A (en) * 1997-02-14 1998-01-13 Beyar; George Walker adapter
US6471178B1 (en) * 1997-05-21 2002-10-29 Cabex Ag Device for adjusting the length of a support and method for producing same
GB2371485A (en) * 2001-01-24 2002-07-31 Neumann Benny William Resilient telescopic walking stick
US20050001132A1 (en) * 2003-06-13 2005-01-06 Machael Jay R. Height adjustment cylinder with non-tapered threaded region
US20100107867A1 (en) * 2008-10-30 2010-05-06 Hyundai Motor Company Lifter for lid of motor vehicle
US20120048482A1 (en) * 2009-04-30 2012-03-01 Libervit Device for blocking a passage
US9080370B2 (en) * 2009-04-30 2015-07-14 Libervit Device for blocking a passage
CN105156570A (zh) * 2015-07-20 2015-12-16 常州大学 双杆变节流孔无源单控变阻尼磁流变阻尼器
US10202158B2 (en) * 2016-08-31 2019-02-12 Giant Manufacturing Co., Ltd. Adjustable seat tube structure and bicycle
US10005509B2 (en) * 2016-11-04 2018-06-26 Taiwan Hodaka Industrial Co., Ltd. Bicycle seat cushion lifting and adjusting device

Also Published As

Publication number Publication date
FR2132491B1 (enrdf_load_stackoverflow) 1975-06-20
JPS5521209B1 (enrdf_load_stackoverflow) 1980-06-07
FR2132491A1 (enrdf_load_stackoverflow) 1972-11-17
DE2116699A1 (de) 1972-10-26
GB1335323A (en) 1973-10-24

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