US3418888A - Hydraulic actuator with internal dashpot - Google Patents

Hydraulic actuator with internal dashpot Download PDF

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Publication number
US3418888A
US3418888A US633975A US63397567A US3418888A US 3418888 A US3418888 A US 3418888A US 633975 A US633975 A US 633975A US 63397567 A US63397567 A US 63397567A US 3418888 A US3418888 A US 3418888A
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US
United States
Prior art keywords
cylinder
bore
plug
dashpot
piston
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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
US633975A
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English (en)
Inventor
Jacques H Mercier
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.)
NORMAND TRUST 420 LEXINGTON AVE NEW YORK NY 10170 A NY STATE OF TRUST
NORMAND TRUST
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Individual
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Publication of US3418888A publication Critical patent/US3418888A/en
Assigned to NORMAND TRUST THE reassignment NORMAND TRUST THE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: MERCIER, JACQUES H.
Assigned to NORMAND TRUST, THE 420 LEXINGTON AVE., NEW YORK, NY 10170 A NY STATE OF TRUST reassignment NORMAND TRUST, THE 420 LEXINGTON AVE., NEW YORK, NY 10170 A NY STATE OF TRUST ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: MERCIER, JACQUES, H.
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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
    • F15B15/223—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston with a piston extension or piston recess which completely seals the main fluid outlet as the piston approaches its end position

Definitions

  • the present invention relates to a hydraulic actuator including a cylinder and piston with damping at the end of a stroke, and more particularly to an actuator in which the cylinder has a fluid port adjacent one end thereof and in which the piston is movable toward such end and defines a chamber with respect thereto in communication with the said fluid port, with dashport means to restrict such communication when the piston is moved adjacent said end of the cylinder.
  • the dashpot means are generally provided in the end of the cylinder.
  • the dashpot means comprises a separate member adapted to be placed inside the cylinder against one end of the latter, the member having an axial bore into which a terminal projection of the piston is adapted to move, communication means with a large cross section being provided between the cylinder chamber and the fluid port provided in the cylinder adjacent said end thereof, prior to movement of the terminal projection into the bore of said member and communication means with a small cross section when said projection has entered said bore.
  • means are provided substantially to suspend the dashpot eflect as soon as the piston moves in the opposite direction even while the projection is still in the bore of the dashpot member in order to avoid any unnecessary slowdown in operation.
  • FIG. 1 is a general schematic view of an actuator to which the invention is applied;
  • FIG. 2 is a view on a larger scale of one end of the actuator, in a longitudinal section along the line IIII of FIG. 3,
  • FIG. 3 is a corresponding view in cross section along the line 1IIIII of FIG. 2;
  • FIG. 4 shows a one-way valve of the device in a section along the line IVIV of FIG. 3;
  • FIG. 5 is a perspective view of a split bushing retainer for the dashpot member
  • FIG. 6 is a perspective exploded view illustrating the mounting of the dashpot member
  • FIG. 7 is a fragmentary view, similar to FIG. 2, but concerning a variant of the retainer for the dashpot member.
  • a threaded sleeve 17 is secured as by welding to the side Wall 11 of the cylinder 10 adjacent end plug 12 and is designed to receive a pipe line (not shown).
  • the side wall 11 of the cylinder 10 has an opening 18 defining a fluid port aligned with the vbore of sleeve 17.
  • a piston 19 is slidingly mounted in the cylinder 10 and has encompassing seal rings 20.
  • a piston rod 21 secured to piston 19 extends through the opposite end 10' of the cylinder.
  • the portion of the cylinder 10 between plug 12 and piston 19 defines a chamber 22 in communication with the sleeve 17, dashpot means being provided to restrict such communication when the piston 19 is moved to the immediate proximity of the plug 12.
  • such dashpot means comprises a member 23 shown in a perspective view in FIG. 6, which is separate from the cylinder 10 and which is adapted to be placed inside the latter against the plug 12.
  • the member 23 is in the form of a cylindrical plug having one end wall 25 against plug 12 and the other end Wall 24 forming a wall of chamber 22.
  • the outer surface 26 of the plug is of diameter such that it can be fit without much play in the bore of the cylinder 10.
  • the outer surface 26 has an annular groove adjacent end wall 24 in which a seal ring 27 is positioned.
  • the member 23 has an internal bore having two portions 28, 29 with different diameters, the portion 28 adjacent the end wall 24 having a smaller diameter than the portion 29 adjacent end wall 25.
  • the bore portions 28, 29 are designed to receive at the end of the inner stroke of the piston 19, an axial terminal projection 30 of the latter, which is engaged with minimum clearance in the smaller diameter portion 28, while an inter-communication space 31 is provided by the larger diameter portion 29.
  • the member 23 has a radial bore 32 with a large cross section which extends between the internal bore of member 23 and its periphery 26 and which is of enlarged diameter as at 33 at its outer end, preferably of the same diameter as the opening 18 in the wall 11.
  • a resilient bushing 34 split as at 35 is forced into the opening 18 and enlarged diameter portion 33 resiliently to lock member 23 in the cylinder 10.
  • the bore of bushing 34 defines a fluid passage 36 of the same diameter as the bore 32.
  • a port 47 is provided in the side wall 11 aligned with the bore 46 and receives a plug 48 forming a drain plug.
  • end closure plug 12 provided with the car 13 is independent of the dashpost member 23. Consequently, identical plugs 12 with cars 13 can be provided, and it is merely necessary to form the portion 15 with a desired diameter as by a cut-oil lathe, to give it a diameter corresponding to each cylinder. The result is a simplification and considerable economy in manufacture.
  • the arrangement is similar to that described above with reference to FIGS. 1 to 6, but the retainer for the member 23 is not a bushing but a hollow plug 50 which is screwed into the sleeve 17 and provides a passage 51 for the fluid.
  • a hydraulic deevice comprising a cylinder having opposed closed ends, a piston slidably mounted in said cylinder and defining a chamber with respect to one of said closed ends, a piston rod secured to said piston and extending axially of said cylinder through the other end thereof, said cylinder having a fluid port in the wall thereof adjacent said first end, a plug positioned in said cylinder adjacent the first end of the latter, said plug having an axial bore, said bore having longitudinally aligned small diameter and large diameter ortions, the
  • said plug having a radial passageway aligned at its outer end with said fluid port and in communication therewith and aligned at its inner end with the enlarged diameter portion of said bore, said plug having an additional radial passageway having its inner end in communication with the enlarged diameter portion of said bore, and having an additional passageway in communication at one end with said last named radial passageway and at its other end with said chamber, said additional passageway and said associated radial passageway being of smaller diameter than the radial passageway in communication with said fluid port, said piston having an axial extension on the side thereof adjacent said chamber, said extension being of diameter substantially equal to the small diameter portion of said bore in said plug whereby when said piston has moved adjacent said first end of said cylinder and said extension has moved into said small diameter portion of said bore, communication between said chamber and said fluid port will be solely through said additional passageway and associated radial passageway to provide a dashpot action, said radial passageway in said plug aligned with said fluid

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Damping Devices (AREA)
US633975A 1966-04-27 1967-04-26 Hydraulic actuator with internal dashpot Expired - Lifetime US3418888A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR59342A FR1483936A (fr) 1966-04-27 1966-04-27 Dispositif de cylindre et piston avec amortissement en fin de course

Publications (1)

Publication Number Publication Date
US3418888A true US3418888A (en) 1968-12-31

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ID=8607266

Family Applications (1)

Application Number Title Priority Date Filing Date
US633975A Expired - Lifetime US3418888A (en) 1966-04-27 1967-04-26 Hydraulic actuator with internal dashpot

Country Status (3)

Country Link
US (1) US3418888A (de)
DE (1) DE1600539B2 (de)
FR (1) FR1483936A (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5271699U (de) * 1975-11-25 1977-05-28
JPS5276895U (de) * 1975-12-05 1977-06-08
JPS551094U (de) * 1979-06-26 1980-01-07
US4228725A (en) * 1978-06-13 1980-10-21 Kenneth Jai Rotary piston
US4319504A (en) * 1979-03-08 1982-03-16 Rolf Peddinghaus Damping device for abruptly occurring forces in a shear or shear press machine
US4517878A (en) * 1981-10-20 1985-05-21 Hitachi Construction Machinery Co., Ltd. Shock absorbing device for hydraulic cylinder
FR2670248A1 (fr) * 1990-12-05 1992-06-12 Mannesmann Ag Verin a amortissement aux positions d'extremite.
US5357847A (en) * 1991-04-17 1994-10-25 Hytork Actuators Limited Pressure vessels having end closures and retainers
US6571683B2 (en) * 2000-10-13 2003-06-03 Hoerbiger Hydraulik Gmbh Hydraulic cylinder
DE19754352B4 (de) * 1996-12-06 2004-01-29 Smc Corp. Fluiddruckzylinder

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR825812A (fr) * 1937-08-20 1938-03-15 Nat Pneumatic Co Perfectionnements aux moteurs pneumatiques de commande des portes
GB562073A (en) * 1943-02-11 1944-06-16 Automotive Prod Co Ltd Improvements in or relating to fluid pressure cylinders, particularly for hydraulic jacks
USRE24532E (en) * 1958-09-09 Cushioning structure for hydraulic cylinders
US3303746A (en) * 1965-12-29 1967-02-14 Westinghouse Air Brake Co Cushioned cylinder arrangement having a combined check valve and needle valve

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE24532E (en) * 1958-09-09 Cushioning structure for hydraulic cylinders
FR825812A (fr) * 1937-08-20 1938-03-15 Nat Pneumatic Co Perfectionnements aux moteurs pneumatiques de commande des portes
GB562073A (en) * 1943-02-11 1944-06-16 Automotive Prod Co Ltd Improvements in or relating to fluid pressure cylinders, particularly for hydraulic jacks
US3303746A (en) * 1965-12-29 1967-02-14 Westinghouse Air Brake Co Cushioned cylinder arrangement having a combined check valve and needle valve

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5271699U (de) * 1975-11-25 1977-05-28
JPS5276895U (de) * 1975-12-05 1977-06-08
US4228725A (en) * 1978-06-13 1980-10-21 Kenneth Jai Rotary piston
US4319504A (en) * 1979-03-08 1982-03-16 Rolf Peddinghaus Damping device for abruptly occurring forces in a shear or shear press machine
JPS551094U (de) * 1979-06-26 1980-01-07
JPS5842648Y2 (ja) * 1979-06-26 1983-09-27 太陽鉄工株式会社 クツシヨン付油圧シリンダ
US4517878A (en) * 1981-10-20 1985-05-21 Hitachi Construction Machinery Co., Ltd. Shock absorbing device for hydraulic cylinder
FR2670248A1 (fr) * 1990-12-05 1992-06-12 Mannesmann Ag Verin a amortissement aux positions d'extremite.
US5207145A (en) * 1990-12-05 1993-05-04 Mannesmann Aktiengesellschaft Work cylinder, such as the work cylinder of a rodless piston cylinder
US5357847A (en) * 1991-04-17 1994-10-25 Hytork Actuators Limited Pressure vessels having end closures and retainers
DE19754352B4 (de) * 1996-12-06 2004-01-29 Smc Corp. Fluiddruckzylinder
US6571683B2 (en) * 2000-10-13 2003-06-03 Hoerbiger Hydraulik Gmbh Hydraulic cylinder

Also Published As

Publication number Publication date
FR1483936A (fr) 1967-06-09
DE1600539B2 (de) 1977-01-13
DE1600539A1 (de) 1970-04-02

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Legal Events

Date Code Title Description
AS Assignment

Owner name: NORMAND TRUST THE, 420 LXINGTON AVE., NEW YORK, NY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:MERCIER, JACQUES H.;REEL/FRAME:004139/0069

Effective date: 19811030

AS Assignment

Owner name: NORMAND TRUST, THE 420 LEXINGTON AVE., NEW YORK, N

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:MERCIER, JACQUES, H.;REEL/FRAME:004173/0199

Effective date: 19830920