US3779396A - Hydraulic buffers - Google Patents

Hydraulic buffers Download PDF

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Publication number
US3779396A
US3779396A US00239668A US3779396DA US3779396A US 3779396 A US3779396 A US 3779396A US 00239668 A US00239668 A US 00239668A US 3779396D A US3779396D A US 3779396DA US 3779396 A US3779396 A US 3779396A
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US
United States
Prior art keywords
piston
cylinder
buffer
annular
sleeve
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
US00239668A
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English (en)
Inventor
E Zielinski
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.)
Rheinmetall Industrie AG
Original Assignee
Rheinmetall GmbH
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 Rheinmetall GmbH filed Critical Rheinmetall GmbH
Application granted granted Critical
Publication of US3779396A publication Critical patent/US3779396A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61G—COUPLINGS; DRAUGHT AND BUFFING APPLIANCES
    • B61G9/00—Draw-gear
    • B61G9/04—Draw-gear combined with buffing appliances
    • B61G9/08—Draw-gear combined with buffing appliances with fluid springs or fluid shock-absorbers; Combinations thereof

Definitions

  • ABSTRACT A hydraulic buffer device of the type in which a piston is slidable in a cylinder and has a throttle aperture which is controlled by a regulating pin whose cross section varies along its length.
  • the throttle aperture is closable by a valve member which is spring loaded into theclosing position. On rapid entry of the piston into the cylinder the valve member-is unsealed and a relatively low resistance to piston travel is afforded.
  • valve cone is located at one end of a sleeve guided on a cylindrical section of the regulating pin, the other end of which sleeve forms an annular cylinder chamber with a section of lesser diameter adjoining the cylindrical section, the wall of which chamber has a throttle bore.
  • the closing speed of the valve cone is determined according to the dimensions of the throttle bore, in that the pressure fluid located in the cylinder chamber has to be pushed through the throttle bore by the force of the valve spring.
  • the load characteristic of the closing spring of the valve cone is in this case appropriately arranged so that in the case of low entry speeds depending on the buffer stroke an approximately constant buffer force results.
  • a force pattern of this type results in the buffer force of the mechanical spring increasing as the piston enters the buffer, whereas the spring force of the closing spring of the pressure limiting valve is reduced and thus due to the opening of the valve the fluid pressure in the buffer cylinder is reduced.
  • FIGS. 1-3 show a buffer and draw gear device for central buffer couplings with one embodiment of hydraulic buffer device according to the invention shown in longitudinal section, in various positions.
  • FIGS. 4 and 5 show the hydraulic buffer device in various positions of the buffer piston in longitudinal section as a partial section of FIG. 1 on an enlarged scale.
  • FIG. 3 shows a mechanical hydraulic buffer and draw gear device in the starting position
  • FIG. 1 shows the device in the pushing position in the case of impact
  • FIG. 2 shows it in the pulling position
  • the reference numeral 1 indicates the housing of the buffer and draw gear device forming a closed unit.
  • the housing consists of the cup-shaped part In receiving the hydraulic part, an adjoining sleeve 1b and a support sleeve 1c serving for supporting the mechanical spring.
  • the unit is rigidly secured to a carriage on the longitudinal central axis thereof.
  • a moving part 2 of the device is located in the housing.
  • the device has, at its end projecting from the housing, a coupling part 3 for the flexible attachment of the central buffer coupling and, at its other end, a piston rod 4a with a buffer piston 4, which projects into a hydraulic cylinder 5 formed in the cup-shaped part la.
  • the mechanical spring mechanism comprises two annular spring columns 6 and 7 arranged concentrically around the moving part 2.
  • the outer annular spring column 6 is fixed between an annular flange 3 secured to the movable part 2 of the device and a shoulder 9 of a sleeve 10 movable relative to the movable part 2.
  • the inner annular spring column 7 is fixed between an annular flange 11 secured to the sleeve 10 and a collar 12 of a sleeve 13, which is slidably guided on a boss 14, which is located on a removable end wall 15 of the cylinder.
  • a regulating pin 17 is secured in an end wall 16 of the cylinder opposite the piston 41 and extends through a central throttle aperture 18 in the piston into a hollow piston rod 4a.
  • the regulating pin has, firstly, a section 19 of tapering diameter, a cylindrical section 20 of greater diameter and a cylindrical section 21 of lesser diameter.
  • the diameter of the throttle aperture 18 is such that a narrow annular clearance remains between it and the periphery of the cylindrical section 20 (FIGS. 4 and 5).
  • a sleeve 22 of substantially greater length than that of the section is guided on the cylindrical section 20, which sleeve has at one end a valve cone 23 and at its other end a shoulder 25 guided on the section 21 of lesser diameter forming an annular cylinder chamber 24.
  • a throttle bore 26 is provided in the wall of the cylinder chamber.
  • the sleeve 22 with the valve cone 23 is supported against a spring washer 28 by a coil spring 27 acting as a closing spring, which spring washer 28 is attached to the end of the cylindrical section 21 of the regulating pin.
  • the closing speed of the valve 23 depends on the load characteristic of the closing spring and the cross section of the throttle bore 26 in the wall of the cylinder chamber 24.
  • valve cone 23 forms a pressure limiting valve for the pressure fluid located in the hydraulic cylinder 5, which can pass when the valve is open through the throttle aperture 18 and through bores 29 located in the piston 4 to the other side of the piston, the cylinder space being connected by way of apertures 30 to a compensating chamber 31 surrounding the cylinder.
  • a bore 33 closed by a resilient valve plate 32 is also provided in the front end of the piston.
  • the compensating chamber 31 does not work as a hydropneumatic pressure reservoir, its function is solely to receive the fluid displaced by the piston rod at the time of the pushing stroke or to supply the additional amount of fluid required at the time of the pulling stroke and to compensate for changes in volume caused by heating.
  • FIG. 3 shows the device in the starting position. This position corresponds to the position of the buffer piston illustrated on a larger scale in the lower half of FIG. 4.
  • FIG. 2 shows the extreme position at the time of the greatest tensile load. During the travel of a railway train the device will adopt a position corresponding approximately to FIG. 3 and FIG. 5 at the bottom.
  • the spring mechanism assumes the position shown in FIG. 1 and in FIG. 5 at the top. Since, in this case, the buffer piston 4 enters the cylinder at a comparatively low speed, sufficient time remains for the pressure fluid located in the cylinder chamber 24 to be displaced through the throttle bore 26 under the action of the force of the closing spring 27, so that the throttle opening 18 remains closed by the valve cone 23. In this way the mechanical spring mechanism is, as it were, locked during travel and at the time of braking the train, so that during these operating conditions the buffer and draw gear device has a high initial stressing force.
  • the buffer piston In the case of greater dynamic loads, as they occur with impacts, the buffer piston is inserted into the cylinder at a comparatively greater speed (FIG. 1).
  • the valve cone 23 actuated by its closing spring 27 is not able to follow the rapid movement of the piston, since for this the fluid located in the cylinder chamber 24 must be pushed out through the throttle bore 26. In consequence and aided by the pressure build-up in front of the piston 4, the valve opens, so that the fluid can pass unhindered through the throttle aperture 18 to the other side of the piston.
  • the hydraulic buffer device has a lower resistance so that even with impacts between lighter carriages no greater acceleration or deceleration values occur.
  • Hydraulic buffer device comprising: a cylinder, a piston slidable in said cylinder, a throttle aperture provided in said piston, a regulating pin for varying the available cross-section of said throttle aperture, said regulating pin being provided with a cross-section which varies in the longitudinal direction of said cylinder, a sleeve guided on a cylindrical section of said regulating pin, a slidably guided annular valve member disposed on one end of said sleeve, an annular cylinder chamber formed by the other end of said sleeve, said annular cylinder chamber being provided with a section of a lesser diameter adjoining the guide end of said sleeve, spring means for biasing said annular member to close said throttle aperture in said piston, and a throttle bore provided in a wall of said annular cylinder chamber for determining the closing speed of said annular valve member.
  • Hydraulic buffer device further comprising: a mechanical buffer and draw gear device, wherein the load characteristics of said spring means and said mechanical buffer are selected to achieve an approximately constant buffer force.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
  • Actuator (AREA)
US00239668A 1971-04-17 1972-03-30 Hydraulic buffers Expired - Lifetime US3779396A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2118655A DE2118655C2 (de) 1971-04-17 1971-04-17 Zug- und Stoßvorrichtung für Mittelpufferkupplungen von Schienenfahrzeugen

Publications (1)

Publication Number Publication Date
US3779396A true US3779396A (en) 1973-12-18

Family

ID=5804966

Family Applications (1)

Application Number Title Priority Date Filing Date
US00239668A Expired - Lifetime US3779396A (en) 1971-04-17 1972-03-30 Hydraulic buffers

Country Status (11)

Country Link
US (1) US3779396A (fr)
BE (1) BE782077A (fr)
CH (1) CH536741A (fr)
DD (1) DD95866A5 (fr)
DE (1) DE2118655C2 (fr)
ES (1) ES400944A1 (fr)
FR (1) FR2136331A5 (fr)
IT (1) IT952194B (fr)
NL (1) NL175892C (fr)
PL (1) PL71171B1 (fr)
SU (1) SU459881A3 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6047839A (en) * 1998-02-03 2000-04-11 Huggins; Russell J. Rail car buffer
US20130228079A1 (en) * 2010-11-11 2013-09-05 Koninklijke Philips Electronics N.V. Food steamer

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE545569C2 (en) * 2021-12-21 2023-10-24 Dellner Couplers Ab Damper arrangement for a railway coupler comprising a damper and a plurality of elastomeric elements, and a railway coupler

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3139989A (en) * 1960-04-27 1964-07-07 Opee Ltd Buffers and draw-gear for railways, tramways and like vehicles
US3160285A (en) * 1960-08-30 1964-12-08 Gloucester Railway Carriage Draft and/or buffing gear for railway vehicles
US3164263A (en) * 1962-08-27 1965-01-05 Railway Transport Inst Draft gear for automatic couplers of railway rolling stock
US3400833A (en) * 1966-04-22 1968-09-10 Acf Ind Inc Railway car cushioning device
US3411635A (en) * 1966-04-01 1968-11-19 Acf Ind Inc Railway car cushioning device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3139989A (en) * 1960-04-27 1964-07-07 Opee Ltd Buffers and draw-gear for railways, tramways and like vehicles
US3160285A (en) * 1960-08-30 1964-12-08 Gloucester Railway Carriage Draft and/or buffing gear for railway vehicles
US3164263A (en) * 1962-08-27 1965-01-05 Railway Transport Inst Draft gear for automatic couplers of railway rolling stock
US3411635A (en) * 1966-04-01 1968-11-19 Acf Ind Inc Railway car cushioning device
US3400833A (en) * 1966-04-22 1968-09-10 Acf Ind Inc Railway car cushioning device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6047839A (en) * 1998-02-03 2000-04-11 Huggins; Russell J. Rail car buffer
US20130228079A1 (en) * 2010-11-11 2013-09-05 Koninklijke Philips Electronics N.V. Food steamer
US10524604B2 (en) * 2010-11-11 2020-01-07 Koninklijke Philips N.V. Food steamer

Also Published As

Publication number Publication date
SU459881A3 (ru) 1975-02-05
DD95866A5 (fr) 1973-02-20
NL175892C (nl) 1985-01-16
BE782077A (fr) 1972-07-31
IT952194B (it) 1973-07-20
FR2136331A5 (fr) 1972-12-22
NL7203151A (fr) 1972-10-19
PL71171B1 (fr) 1974-04-30
NL175892B (nl) 1984-08-16
DE2118655A1 (de) 1972-10-26
ES400944A1 (es) 1975-09-01
CH536741A (de) 1973-05-15
DE2118655C2 (de) 1986-06-05

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