GB2159234A - Hydraulic damper with adjustable bypass - Google Patents

Hydraulic damper with adjustable bypass Download PDF

Info

Publication number
GB2159234A
GB2159234A GB08511312A GB8511312A GB2159234A GB 2159234 A GB2159234 A GB 2159234A GB 08511312 A GB08511312 A GB 08511312A GB 8511312 A GB8511312 A GB 8511312A GB 2159234 A GB2159234 A GB 2159234A
Authority
GB
United Kingdom
Prior art keywords
damper
bypass
compensating chamber
passage
bypass passage
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.)
Granted
Application number
GB08511312A
Other versions
GB2159234B (en
GB8511312D0 (en
Inventor
Hubert Beck
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.)
ZF Boge GmbH
Original Assignee
Boge 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 Boge GmbH filed Critical Boge GmbH
Publication of GB8511312D0 publication Critical patent/GB8511312D0/en
Publication of GB2159234A publication Critical patent/GB2159234A/en
Application granted granted Critical
Publication of GB2159234B publication Critical patent/GB2159234B/en
Expired legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32Details
    • F16F9/44Means on or in the damper for manual or non-automatic adjustment; such means combined with temperature correction
    • F16F9/46Means on or in the damper for manual or non-automatic adjustment; such means combined with temperature correction allowing control from a distance, i.e. location of means for control input being remote from site of valves, e.g. on damper external wall
    • F16F9/466Throttling control, i.e. regulation of flow passage geometry

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

An adjustable hydraulic damper comprises a cylinder 3 divided by a damping piston 2 into upper and lower working chambers 4 and 5. A bypass valve 10 is provided in the region of the base 12 of the damper and damps vibrations in parallel with a throttle member 6 in the piston. The bypass valve 10 regulates the cross-sectional area of a bypass passage 14, 11 which connects the upper working chamber 4 with the surrounding compensating chamber 9. The provision of the valve 10 in the region of the base 12 of the damper enables the damper to be used not only as a vibration damper but also as a wheel-locating suspension strut and as a suspension strut cartridge. The valve 10 may be adjusted electromagnetically. There may be a plurality of tubular passages 14 passing through the compensating chamber 9, each controlled by a valve in the base. The bypass passage may instead be annular and surround the inner or outer cylinder. <IMAGE>

Description

SPECIFICATION An adjustable hydraulic damper This invention relates to an adjustable hydraulic damper comprising a cylinder divided by a damping piston on a piston rod into upper and lower working chambers filled with damping fluid, the piston being provided with throttle means for damping vibrations, a compensating chamber formed between the cylinder and an outer tube, the lower working chamber being connected to the compensating chamber through at least one flow connection and the upper working chamber being connected to the compensating chamber through a bypass passage, and a bypass valve provided in the bypass passage which regulates the crosssectional area of the bypass passage so as to control the damping in parallel with the throttle means.
Dampers are already known (e.g. DE-OS 32 31 739), in which the damping force can be altered by a bypass valve in a bypass connection and which is mounted on the cylinder or on the piston rod guide. Such a bypass valve regulates the change in cross-sectional area of the bypass connection either in accordance with pressure or electromagnetically. Such an arrangement has the drawback that it can only be used in dampers which have no additional helical spring. For reasons of available space, when a pressure connection or a control valve is required to be used outside the outer tube, such a construction can no longer be employed. This applies for example to spring strut suspension units with helical springs, dampers with helical springs and cartridges for incorporation in suspension struts.
Moreover such a construction is likewise not capable of being used in dampers in which an additional protective tube is needed.
However, even when the bypass valve is provided within the helical spring, in the region of the piston rod guide, and for the greater part above the spring plate, such dampers only have a limited use.
Furthermore dampers are known (e.g. DE OS 29 11 768) in which a bypass valve is arranged within a hollow piston rod. In this case a solenoid is provided in the upper part of the piston rod, within which an armature is axially movable and an electromagnetically actuated control slide cooperates with bypass bores in the piston rod. The drawback of this arrangement is the necessarily high cost of construction which requires connecting pipes, armatures, a diaphragm and its mounting.
Also it is usually necessary to employ different valve systems in series and a long tension rod is required within the hollow piston rod. The machining steps necessary for arranging the controllable bypass valve within the piston rod result in a weakening of this piston rod so that only under special circumstances can wheellocating forces be handled. Moreover the axial dimensions of the damper are usually increased by the provision of the bypass valve within the piston rod.
The aim of the invention is therefore to provide a variable damping force in a damper by the use of a bypass connection of such a design that can be employed both in a vibration damper and in a wheel-locating suspension strut and also in a suspension strut cartridge, the bypass valve being a standard component which not only can be mounted readily but also can be replaced in the built-in assembly and which can be removed from a defective damper for re-use in a newly provided damper without having to take into account assembly or modification problems.
According to the invention there is provided an adjustable hydraulic damper which comprises a cylinder divided by a damping piston on a piston rod into upper and lower working chambers filled with damping fluid, the piston being provided with throttle means for damping vibrations, a compensating chamber formed between the cylinder and an outer tube, the lower working chamber being connected to the compensating chamber through a flow connection and the upper working chamber being connected to the compensating chamber through a bypass passage which opens into the compensating chamber in the region of the base of the damper, and a bypass valve provided in the region of the base of the damper which regulates the crosssectional area of the bypass passage so as to control the damping in parallel with the throttle means.
An important feature of the invention is that the bypass valve is mounted in the lower part of the damper so that the damper can be used in circumstances when only a narrow space is available. Therefore a damper in accordance with the invention can be used as a damper with a coil spring, as a wheel-locating suspension strut and also as a cartridge for replacement in a suspension strut. When the damper is used in wheel-locating suspension struts there is no weakening of the piston rod guide assembly which has to be taken into account.
In a preferred embodiment of the invention the bypass passage comprises a tubular connection which extends through the compensating chamber. In this arrangement a conventional vibration damper which has a compensating chamber may be used with a tubular connection of either a flexible or a rigid type which extends from the upper part of the damper, namely the upper working chamber, into the lower part of the damper, preferably its base. Then, in the base of the damper, the tubular connection leads into a flow passage in which the bypass valve is provided.
In an alternative embodiment of the invention the bypass passage is coaxial with and disposed outside the working cylinder. In such an embodiment the damper has rotational symmetry and the bypass passage is of annular cross-section so that a large volume of damping fluid can flow through the bypass passage. The coaxial bypass passage may conveniently be formed between the outer tube and a tube surrounding the outer tube and be connected to the compensating chamber through a bore provided in the outer tube.
Thus in a two-tube damper an additional third tube does not have to be provided to form the bypass passage.
Preferably, a plurality of bypass valves are provided, distributed circumferentially around the damper in the region of its base. With a single bypass passage of large cross-sectional area and the provision of several bypass valves which together regulate the area of that passage it is possible to regulate a large fluid flow. In such an arrangement there may be provided two valves, or three valves spaced apart at 120 or indeed, according to the space available, more than three valves.
Instead of a single bypass passage opening into the compensating chamber, a plurality of individual passages may be provided which open into the compensating chamber from the bypass passage, the cross-sectional area of each individual passage being regulated by a respective bypass valve.
In order to achieve a large degree of interchangeability, a simple mounting and utilisation of standard components, the or each bypass valve may be secured to the damper by means of a screw-threaded connection.
This allows employment of bypass valves of the same kind to be used which ensure constant regulation of the bypass for a given bore. In this manner the dimensions of the cross-sectional area of the bypass are only dependent upon the type of damper or suspension strut. When the damper is used in a spring strut cartridge the bypass valve can be unscrewed from outside so that subsequently the inner components of the suspension strut can be removed and after the insertion of an appropriate cartridge and the subsequent screw ing-in of the bypass valve, the operation of the strut is restored.
A particularly advantageous construction of the bypass passage and disposition of the bypass valve is achieved when the bypass valve is screwed into the base substantially at right angles to the longitudinal central axis of the damper.
Preferably, the or each bypass valve is controlled by an electromagnet. Conveniently, an armature of the electromagnet acts on a movable control slide of the bypass valve.
This arrangement is particularly suitable for when control of the bypass valve is remote from the bypass passage. In this case the control slide may be a component of the damper and be matched to the corresponding cross-sectional area of the passage, or in different versions of dampers the electromagnet together with the control slide may form a unit which can be inserted into a damper of the same version.
In a preferred construction the control slide is movable in a stepped bore in the same axial direction as the armature during energisation of the electromagnet. Preferably the armature acts on the control slide against the bias of a return spring. The return spring is arranged to keep the bypass passage permanently open when the electromagnet is not energised.
When the magnet is energised the bypass passage is closed by the control slide and on de-energisation of the magnet the spring acts to dispiace both the control slide and also the armature of the electromagnet in the axial direction to open the bypass passage.
Several embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings:- in which Figure 1 is a sectional view of the lower part of a vibration damper in accordance with the invention; Figure 2 is a section on the line ll-ll of Figure 1; Figure 3 is a part sectional view of the whole of the damper shown in Figure 1; Figure 4 is a part sectional view of a damper similar to that of Figures 1 to 3 but which has been modified to form a wheellocating suspension strut; Figure 5 is a part sectional view of a damper similar to that of Figures 1 to 3 but which has been modified to form a suspension strut unit or cartridge; Figure 6 is a sectional view of the lower part of another vibration damper similar to that of Figure 1 but which has three bypass valves;; Figure 7 is a section on the line VII-VII of Figure 6; Figure 8 is a sectional view of the lower part of a further damper similar to that of Figures 6 and 7; Figure 9 is section on the lines IX-IX of Figure 8; and Figure 10 is a sectional view of yet another damper in accordance with the invention.
The hydraulic damper illustrated in Figures 1 to 3 comprises a working cylinder 3 and a damping piston 2 secured on the end of a piston rod 1. The damping piston 2 divides the interior of the working cylinder 3 into an upper working chamber 4 and a lower working chamber 5. The damping piston 2 has throttle members 6 which act to damp vibrations. Attachment means 22 and 29 at the top and bottom of the damper are provided to secure the damper in the vehicle. As the piston rod 1 works in the cylinder 3 it displaces damping fluid from the lower chamber 5 through a base valve 7 into a compensating chamber 9. The compensating chamber 9 is formed by the working cylinder 3 and a surrounding tube 8.
The upper working chamber 4 is connected to the compensating chamber 9 through a bypass passage which comprises a tubular connection 14 extending within the compensating chamber 9, and a passage 11 in the base 1 2 of the damper which opens into the compensating chamber. An electromagnetically controlled bypass valve 10 provided in the passage 11 has a control slide 1 3 which regulates the cross-sectional area of the passage 11 so as to either open or close the bypass from the upper working chamber 4 through the tubular connection 14 and the passage 11 to the compensating chamber 9.
The bypass valve 10 comprises an electromagnet 1 9 with an integrated coil and an armature 20 of magnetic material, both of which are secured to the base 1 2 of the damper by means of a screw-threaded connection 23. The bypass valve 10 is arranged approximately at right angles to the longitudinal central axis 1 7 of the damper. The armature acts on the control slide 1 3 against the bias of a return spring 21 which produces a permanent force in a direction towards the open position of the valve 1 0. The passage 11 is sealed off from atmosphere by an O-ring 24 and a ball 25 pressed into the passage 11. The electromagnet 1 9 is connected to a supply of electric current by the connection 26.
The outer tube 8 is secured to an extension of the base 1 2 by a mechanical connection 27 and is sealed off by a seal 28. The mechanical connection 27 comprises regions distributed around the periphery of the outer tube 8 which are partially deformed inwardly.
In the standard damper shown in Figure 3 the lower attachment point 22 and the upper attachment point 29 are not suitable for locating a wheel. As shown the tubular connection 14 comprises a pipe which leads from the upper working chamber 4 into the passage 11 in the base 12.
In Figure 4 there is illustrated a wheellocating suspension strut in which, in contrast to the damper of Figure 3, an additional lug 30 is provided, for attaching the strut to an axle limb. The outer tube 8 is connected at its upper region to a spring abutment plate 31 serving as a lower abutment for a coil spring.
This type of wheel-locating spring strut is a normal component of a McPherson suspension. In this embodiment there is also a tubular connection 1 4 from the upper working chamber 4 through the passage 11 to the compensating chamber 9. The control slide of the bypass valve is slidable within a stepped bore 32 and is acted on by the separate armature 20 of the electromagnet 19 against the bias of the return spring 21. A connecting pin 33 is provided for attaching the strut to the vehicle frame.
Figure 5 shows a wheel-locating suspension strut in which an exterior tube 34 is provided with a screwthreaded cap 35, the interior of which receives a subsequently inserted cartridge. This cartridge for subsequent insertion is in the form of a complete damper similar to that of Figures 1 to 3 and which comprises the piston rod 1, the damper piston 2, the working cylinder 3 and the outer tube 8.
These components can be replaced in the event of wear so that the exterior tube 34, the spring abutment plate 31, the lug 30 and the limb of the axle secured to it can remain mounted in the vehicle. This replacement is achieved by unscrewing the bypass valve 10 so that axial access is then given to the cartridge. Otherwise the wheel-locating suspension strut is equivalent to that of Figure 4.
When a defective damper is to be replaced, the electromagnet, complete with its coil and armature and the connection 26 can be used with the replacement damper.
Figures 6 and 7 show a damper which permits large volume exchange and in which variable control is achieved by the use of three bypass valves 10. These bypass valves 10 are disposed at an angle of 1 20 degrees to each other in the base 1 2 of the damper and control the volume of fluid which can flow through the tubular connection and the passage 11 into the compensating chamber 9. As shown in Figure 7 the end of each individual control slide 1 3 is conical, the angle of the cone being 120 in each case so that when all three magnets 1 9 are energised the bypass passage is closed and, by controlling a single electromagnet 1 9 or two of them in parallel, the passage 11 is only partially opened.The parallel energisation of the individual bypass valves 10 enables the damping system to react rapidly and gives the system a wide degree of variability.
Figures 8 and 9 show a damper in which the volume of damping fluid entering the compensating chamber 9 is controlled by three bypass valves 10, each of which regulates the cross-sectional area of respective individual passage 36 which opens into the compensating chamber 9. These individual passages 36 could be of the same diameter or, as shown in Figure 9, they could have different diameters so that by different control of the electromagnets 1 9 different cross-sectional areas for flow can be obtained. The cross-sectional areas for flow can be matched and controlled in accordance with the prevailing driving conditions with the aid of appropriate electronics. However the provision of such electronics is not an essential requirement for the operation of the actual damper.
In Figure 10 a two-tube damper is illustrated as a further alternative. A large-volume bypass passage coaxial with and disposed outside the working cylinder 3 is formed between the outer tube 8 and an additional tube 1 5 surrounding the outer tube 8. The damping medium flows from the upper working chamber 4 through a transverse bore 37 into the annular bypass connection 14 and from there through a bore 16 in the outer tube 8 into the compensating chamber 9. The passage 11 of Figures 1 to 9 is equivalent to the bore 1 6 and the armature 20 of the electromagnet 1 9 acts on the control slide 1 3 of the bypass valve which regulates the cross-sectional area of the bore 16.

Claims (9)

1. An adjustable hydraulic damper comprising a cylinder divided by a damping piston on a piston rod into upper and lower working chambers filled with damping fluid, the piston being provided with throttle means for damping vibrations, a compensating chamber formed between the cylinder and an outer tube, the lower working chamber being connected to the compensating chamber through a flow connection and the upper working chamber being connected to the compensating chamber through a bypass passage which opens into the a compensating chamber in the region of the base of the damper, and a bypass valve provided in the region of the base of the damper which regulates the crosssectional area of the bypass passage so as to control the damping in parallel with the throttle means.
2. A damper according to Claim 1, in which the bypass passage comprises a tubular connection which extends through the compensating chamber.
3. A damper according to Claim 1, in which the bypass passage is co-axial with and disposed outside the working cylinder.
4. A damper according to Claim 3, in which the coaxial bypass passage is formed between the outer tube and a tube surrounding the outer tube, and a bore provided in the outer tube opens into the compensating chamber from the bypass passage.
5. A damper according to any of the preceding claims, in which a plurality of bypass valves are provided, distributed circumferencially around the damper in the region of its base.
6. A damper according to Claim 5, in which the plurality of bypass valves together regulate the cross-sectional area of a single passage which opens into the compensating chamber from the bypass passage.
7. A damper according to Claim 5, in which a plurality of individual passages open into the compensating chamber from the bypass passage, the cross-sectional area of each individual passage being regulated by a respective bypass valve.
8. A damper according to any of the preceding claims, in which the or each bypass valve is secured to the damper by means of a screw-threaded connection.
9. An adjustable hydraulic damper substantially as described herein with reference to and as illustrated by the accompanying drawing.
9. A damper according to Claim 8 in which the or each bypass valve is screwed into the base substantially at right angles to the longitudinal central axis of the damper.
10. A damper according to any of the preceding claims, in which the or each bypass valve is controlled by an electromagnet.
11. A damper according to Claim 10, in which an armature of the electromagnet acts on a movable control slide of the bypass valve.
12. A damper according to Claim 11, in which the armature acts on the control slide against the bias of a return spring.
1 3. An adjustable hydraulic damper substantially as described herein with reference to and as illustrated by Figures 1 to 3 of the accompanying drawings.
14. An adjustable hydraulic damper according to Claim 1 3 but modified to form a wheellocating suspension strut substantially as described herein with reference to and as illustrated by Figure 4 of the accompanying drawings.
1 5. An adjustable hydraulic damper according to Claim 1 3 but modified to form a suspension strut unit or cartridge substantially as described herein with reference to and as illustrated by Figure 5 of the accompanying drawings.
1 6. An adjustable hydraulic damper substantially as described herein with reference to and as illustrated by Figures 6 and 7 of the accompanying drawings.
1 7. An adjustable hydraulic damper substantially as described herein with reference to and as illustrated by Figures 8 and 9 of the accompanying drawings.
1 8 An adjustable hydraulic damper substantially as described herein with reference to and as illustrated by Figure 10 of the accompanying drawings.
CLAIMS Amendments to the claims have been filed, and have the following effect: Claims 1-4,6, 9, and 13-18 above have been deleted or textually amended.
New or textualiy amended claims have been filed as follows: Claims 5, 7, 8 and 10-12 above have been re-numbered as 3, 4, 5, 6, 7 and 8 and their appendancies corrected.
1. An adjustable hydraulic damper comprising a cylinder divided by a damping piston on a piston rod into upper and lower working chambers filled with damping fluid, the piston being provided with throttle means for damping vibrations, a compensating chamber formed between the cylinder and an outer tube, the lower working chamber being connected to the compensating chamber through a flow connection and the upper working chamber being connected to the compensating chamber through a bypass passage which is disposed outside the compensating chamber and is formed between the outer tube and a tube surrounding the outer tube, and through at least one passage which leads from the bypass passage and opens into the compensating chamber in the region of the base of the damper, and at least one bypass valve provided in the region of the base of the damper which regulates the cross-sectional area of the passage which opens into the compensating chamber so as to control the damping in parallel with the throttle means.
2. A damper according to Claim 1, in which the or each passage which leads from the bypass passage and opens into the compensating chamber comprises a bore provided in the outer tube.
GB08511312A 1984-05-17 1985-05-03 Hydraulic damper with adjustable bypass Expired GB2159234B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19843418262 DE3418262A1 (en) 1984-05-17 1984-05-17 HYDRAULIC, ADJUSTABLE SHOCK ABSORBER

Publications (3)

Publication Number Publication Date
GB8511312D0 GB8511312D0 (en) 1985-06-12
GB2159234A true GB2159234A (en) 1985-11-27
GB2159234B GB2159234B (en) 1987-07-29

Family

ID=6236064

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08511312A Expired GB2159234B (en) 1984-05-17 1985-05-03 Hydraulic damper with adjustable bypass

Country Status (7)

Country Link
JP (1) JPS60260732A (en)
BR (1) BR8501823A (en)
DE (1) DE3418262A1 (en)
ES (1) ES8606597A1 (en)
FR (1) FR2564549A1 (en)
GB (1) GB2159234B (en)
IT (2) IT1183616B (en)

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0202941A2 (en) * 1985-05-23 1986-11-26 Enidine Incorporated Adjustable double-acting damper
EP0241677A1 (en) * 1986-04-12 1987-10-21 Körber Ag Damper with adjustable damping characteristics
EP0277259A1 (en) * 1985-11-25 1988-08-10 AlliedSignal Inc. A variable rate shock absorber
US4854429A (en) * 1987-12-18 1989-08-08 Casey Gary L Variable rate shock absorber and system therefor
FR2636697A1 (en) * 1988-09-17 1990-03-23 Fichtel & Sachs Ag SINGLE-TUBE VIBRATION DAMPER WITH MODIFIABLE DAMPING FORCE
EP0530886A1 (en) * 1991-09-03 1993-03-10 General Motors Corporation Low-level damping valve and method for a semi-active hydraulic damper
EP0601982A1 (en) * 1992-12-09 1994-06-15 Öhlins Racing Ab Device relating to a shock absorber
DE19706683A1 (en) * 1997-02-20 1998-07-16 Mannesmann Sachs Ag Oscillation dampener has piston and dampening medium passages fitted
US6135250A (en) * 1997-06-04 2000-10-24 Mannesmann Sachs Ag Hydropneumatic vibration damper of variable damping force
NL1015989C2 (en) * 2000-08-22 2002-02-25 Koni Bv Rotation damper with valve.
WO2009066155A1 (en) * 2007-11-19 2009-05-28 Magneti Marelli Copaf Companhia Fabricadora De Peças Hydraulic variable shock absorber with flow control valve
CN101915280A (en) * 2010-08-11 2010-12-15 太原科技大学 Stepless damping-force adjustable shock absorber
CN101070888B (en) * 2007-06-05 2011-08-31 浙江中兴减震器制造有限公司 Structure-improved automobile shock absorber
US11162555B2 (en) 2008-08-25 2021-11-02 Fox Factory, Inc. Methods and apparatus for suspension lock out and signal generation
US11168758B2 (en) 2009-01-07 2021-11-09 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11173765B2 (en) 2009-01-07 2021-11-16 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11279198B2 (en) 2009-10-13 2022-03-22 Fox Factory, Inc. Methods and apparatus for controlling a fluid damper
US11279199B2 (en) 2012-01-25 2022-03-22 Fox Factory, Inc. Suspension damper with by-pass valves
US11299233B2 (en) 2009-01-07 2022-04-12 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11306798B2 (en) 2008-05-09 2022-04-19 Fox Factory, Inc. Position sensitive suspension damping with an active valve
US11408482B2 (en) 2009-01-07 2022-08-09 Fox Factory, Inc. Bypass for a suspension damper
US11472252B2 (en) 2016-04-08 2022-10-18 Fox Factory, Inc. Electronic compression and rebound control
US11499601B2 (en) 2009-01-07 2022-11-15 Fox Factory, Inc. Remotely operated bypass for a suspension damper
US11549565B2 (en) 2009-01-07 2023-01-10 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11619278B2 (en) 2009-03-19 2023-04-04 Fox Factory, Inc. Methods and apparatus for suspension adjustment
US11629774B2 (en) 2012-05-10 2023-04-18 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11708878B2 (en) 2010-01-20 2023-07-25 Fox Factory, Inc. Remotely operated bypass for a suspension damper
US11897571B2 (en) 2008-11-25 2024-02-13 Fox Factory, Inc. Seat post
US11958328B2 (en) 2011-09-12 2024-04-16 Fox Factory, Inc. Methods and apparatus for suspension set up
US12044286B2 (en) 2009-01-07 2024-07-23 Fox Factory, Inc. Compression isolator for a suspension damper
US12103349B2 (en) 2009-03-19 2024-10-01 Fox Factory, Inc. Methods and apparatus for selective spring pre-load adjustment
US12122205B2 (en) 2018-11-28 2024-10-22 Fox Factory, Inc. Active valve for an internal bypass

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4310341C1 (en) * 1993-03-31 1994-08-25 Bilstein August Gmbh Co Kg Controllable vibration damper for motor vehicles
DE4424432C2 (en) * 1994-07-12 1998-04-16 Mannesmann Sachs Ag Vibration damper, especially shock absorber, with variable damping force
JP3583361B2 (en) * 1999-12-07 2004-11-04 ツェットエフ ザックス アクチエンゲゼルシャフト Vibration damper with adjustable damping force
DE102012220157A1 (en) * 2012-11-06 2014-06-26 Zf Friedrichshafen Ag Vibration damper has electrically operable control valve arrangement that is provided in housing, and cap that is enclosed in control valve arrangement of housing
DE102017222232A1 (en) 2017-12-08 2019-06-13 Zf Friedrichshafen Ag Vibration damper with adjustable damping force

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB942328A (en) * 1960-12-01 1963-11-20 Armstrong Patents Co Ltd Improvements in or relating to adjustable hydraulic shock absorbers
GB1021877A (en) * 1963-12-18 1966-03-09 Armstrong Patents Co Ltd Improvements in or relating to adjustable hydraulic shock absorbers
GB1185074A (en) * 1966-04-16 1970-03-18 Fichtel & Sachs Ag Improvements in or relating to Oscillation Dampers
US3532194A (en) * 1968-11-25 1970-10-06 Gen Motors Corp Shock absorber with variable damping
GB1222806A (en) * 1968-04-11 1971-02-17 Arie Adrianus De Koning Improvements in or relating to hydraulic telescopic shock absorbers
GB1354385A (en) * 1971-11-16 1974-06-05 Armstrong Patents Co Ltd Telescopic hydraulic shock absorbers
GB1491208A (en) * 1973-11-21 1977-11-09 Oleo Int Holdings Ltd Liquid dampers

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB813703A (en) * 1956-05-17 1959-05-21 Armstrong Patents Co Ltd Improvements in or relating to hydraulic shock absorbers for vehicle suspension
DE1405781B1 (en) * 1960-12-01 1970-06-18 Armstrong Patents Co Ltd Electrically remote controllable hydraulic shock absorbers, especially for land vehicles
BE686322A (en) * 1965-09-03 1967-02-15
JPS5514337A (en) * 1978-07-14 1980-01-31 Honda Motor Co Ltd Oil hydraulic damper for vehicle
DE2911768C2 (en) * 1979-03-26 1983-01-20 F & O Electronic Systems GmbH & Co, 6901 Neckarsteinach Adjustable shock absorbers, in particular for motor vehicles
DE3231739A1 (en) * 1982-08-26 1984-03-01 Fichtel & Sachs Ag, 8720 Schweinfurt TWO TUBE VIBRATION DAMPER OR SHOCK ABSORBER WITH VARIABLE DAMPING FORCE

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB942328A (en) * 1960-12-01 1963-11-20 Armstrong Patents Co Ltd Improvements in or relating to adjustable hydraulic shock absorbers
GB1021877A (en) * 1963-12-18 1966-03-09 Armstrong Patents Co Ltd Improvements in or relating to adjustable hydraulic shock absorbers
GB1185074A (en) * 1966-04-16 1970-03-18 Fichtel & Sachs Ag Improvements in or relating to Oscillation Dampers
GB1222806A (en) * 1968-04-11 1971-02-17 Arie Adrianus De Koning Improvements in or relating to hydraulic telescopic shock absorbers
US3532194A (en) * 1968-11-25 1970-10-06 Gen Motors Corp Shock absorber with variable damping
GB1354385A (en) * 1971-11-16 1974-06-05 Armstrong Patents Co Ltd Telescopic hydraulic shock absorbers
GB1491208A (en) * 1973-11-21 1977-11-09 Oleo Int Holdings Ltd Liquid dampers

Cited By (53)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0202941A2 (en) * 1985-05-23 1986-11-26 Enidine Incorporated Adjustable double-acting damper
EP0202941A3 (en) * 1985-05-23 1987-06-24 Enidine Incorporated Adjustable double-acting damper
EP0277259A1 (en) * 1985-11-25 1988-08-10 AlliedSignal Inc. A variable rate shock absorber
EP0241677A1 (en) * 1986-04-12 1987-10-21 Körber Ag Damper with adjustable damping characteristics
US4854429A (en) * 1987-12-18 1989-08-08 Casey Gary L Variable rate shock absorber and system therefor
FR2636697A1 (en) * 1988-09-17 1990-03-23 Fichtel & Sachs Ag SINGLE-TUBE VIBRATION DAMPER WITH MODIFIABLE DAMPING FORCE
EP0530886A1 (en) * 1991-09-03 1993-03-10 General Motors Corporation Low-level damping valve and method for a semi-active hydraulic damper
EP0601982A1 (en) * 1992-12-09 1994-06-15 Öhlins Racing Ab Device relating to a shock absorber
US5460355A (en) * 1992-12-09 1995-10-24 Yamaha Motor Co., Ltd. Adjustable shock absorber
EP0816711A2 (en) * 1992-12-09 1998-01-07 Öhlins Racing Ab Adjustable piston type shock absorber
EP0816711A3 (en) * 1992-12-09 1999-02-03 Öhlins Racing Ab Adjustable piston type shock absorber
DE19706683A1 (en) * 1997-02-20 1998-07-16 Mannesmann Sachs Ag Oscillation dampener has piston and dampening medium passages fitted
US6135250A (en) * 1997-06-04 2000-10-24 Mannesmann Sachs Ag Hydropneumatic vibration damper of variable damping force
DE19815214B4 (en) * 1997-06-04 2007-07-05 Zf Sachs Ag Steam force variable hydro-pneumatic vibration damper
WO2002016183A1 (en) * 2000-08-22 2002-02-28 Koni B.V. Rotation damper with valve
CN1296243C (en) * 2000-08-22 2007-01-24 康尼公司 Rotation damper with valve
US7469776B2 (en) * 2000-08-22 2008-12-30 Koni B.V. Rotation damper with valve
NL1015989C2 (en) * 2000-08-22 2002-02-25 Koni Bv Rotation damper with valve.
CN101070888B (en) * 2007-06-05 2011-08-31 浙江中兴减震器制造有限公司 Structure-improved automobile shock absorber
US8292047B2 (en) 2007-11-19 2012-10-23 Magneti Marelli Cofap Companhia Fabricadora De Pecas Hydraulic variable shock absorber with flow control valve
CN102187115A (en) * 2007-11-19 2011-09-14 玛涅蒂玛瑞利可发普零部件制造公司 Hydraulic variable shock absorber with flow control valve
WO2009066155A1 (en) * 2007-11-19 2009-05-28 Magneti Marelli Copaf Companhia Fabricadora De Peças Hydraulic variable shock absorber with flow control valve
CN102187115B (en) * 2007-11-19 2014-06-04 玛涅蒂玛瑞利可发普零部件制造公司 Hydraulic variable shock absorber with flow control valve
US11306798B2 (en) 2008-05-09 2022-04-19 Fox Factory, Inc. Position sensitive suspension damping with an active valve
US11162555B2 (en) 2008-08-25 2021-11-02 Fox Factory, Inc. Methods and apparatus for suspension lock out and signal generation
US11897571B2 (en) 2008-11-25 2024-02-13 Fox Factory, Inc. Seat post
US11173765B2 (en) 2009-01-07 2021-11-16 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11794543B2 (en) 2009-01-07 2023-10-24 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11890908B2 (en) 2009-01-07 2024-02-06 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11299233B2 (en) 2009-01-07 2022-04-12 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11168758B2 (en) 2009-01-07 2021-11-09 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11408482B2 (en) 2009-01-07 2022-08-09 Fox Factory, Inc. Bypass for a suspension damper
US12091122B2 (en) 2009-01-07 2024-09-17 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11499601B2 (en) 2009-01-07 2022-11-15 Fox Factory, Inc. Remotely operated bypass for a suspension damper
US11549565B2 (en) 2009-01-07 2023-01-10 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11976706B2 (en) 2009-01-07 2024-05-07 Fox Factory, Inc. Remotely operated bypass for a suspension damper
US12044286B2 (en) 2009-01-07 2024-07-23 Fox Factory, Inc. Compression isolator for a suspension damper
US11660924B2 (en) 2009-01-07 2023-05-30 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11866120B2 (en) 2009-01-07 2024-01-09 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11619278B2 (en) 2009-03-19 2023-04-04 Fox Factory, Inc. Methods and apparatus for suspension adjustment
US12103349B2 (en) 2009-03-19 2024-10-01 Fox Factory, Inc. Methods and apparatus for selective spring pre-load adjustment
US11920655B2 (en) 2009-03-19 2024-03-05 Fox Factory, Inc. Methods and apparatus for suspension adjustment
US12005755B2 (en) 2009-10-13 2024-06-11 Fox Factory, Inc. Methods and apparatus for controlling a fluid damper
US11279198B2 (en) 2009-10-13 2022-03-22 Fox Factory, Inc. Methods and apparatus for controlling a fluid damper
US11708878B2 (en) 2010-01-20 2023-07-25 Fox Factory, Inc. Remotely operated bypass for a suspension damper
CN101915280A (en) * 2010-08-11 2010-12-15 太原科技大学 Stepless damping-force adjustable shock absorber
US11958328B2 (en) 2011-09-12 2024-04-16 Fox Factory, Inc. Methods and apparatus for suspension set up
US11760150B2 (en) 2012-01-25 2023-09-19 Fox Factory, Inc. Suspension damper with by-pass valves
US11279199B2 (en) 2012-01-25 2022-03-22 Fox Factory, Inc. Suspension damper with by-pass valves
US12038062B2 (en) 2012-05-10 2024-07-16 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11629774B2 (en) 2012-05-10 2023-04-18 Fox Factory, Inc. Method and apparatus for an adjustable damper
US11472252B2 (en) 2016-04-08 2022-10-18 Fox Factory, Inc. Electronic compression and rebound control
US12122205B2 (en) 2018-11-28 2024-10-22 Fox Factory, Inc. Active valve for an internal bypass

Also Published As

Publication number Publication date
JPS60260732A (en) 1985-12-23
ES540676A0 (en) 1986-04-16
FR2564549A1 (en) 1985-11-22
IT8520675A0 (en) 1985-05-13
GB2159234B (en) 1987-07-29
GB8511312D0 (en) 1985-06-12
BR8501823A (en) 1986-04-29
DE3418262C2 (en) 1988-08-04
IT8521797V0 (en) 1985-05-13
ES8606597A1 (en) 1986-04-16
DE3418262A1 (en) 1985-11-21
IT1183616B (en) 1987-10-22

Similar Documents

Publication Publication Date Title
GB2159234A (en) Hydraulic damper with adjustable bypass
US5937975A (en) Vibration damper for a motor vehicle and a vibration damper having a damping valve with adjustable damping force for a motor vehicle
US9810282B2 (en) Damper with digital valve
US5301776A (en) Hydraulic adjustable vibration damper
EP0905408B1 (en) Hydraulic shock absorber
US4973854A (en) Hydraulic shock-absorber and vibration damper with adjustable damping
US5335757A (en) Hydraulic adjustable vibration damper
US5163706A (en) Electro-hydraulic pressure regulating valve assembly for a hydraulic damper
US5163538A (en) Low level damping valve and method for a semi-active hydraulic damper
US4638896A (en) Shock absorbers
US6296092B1 (en) Position-sensitive shock absorber
US5788030A (en) Vibration damper with adjustable damping force
US5067687A (en) Proportional pressure control valve
KR100245765B1 (en) Vibration damper with variable dampimg force
GB2159604A (en) An adjustable hydraulic damper
JPS6179036A (en) Adjustable hydraulic shock absorber
GB1121154A (en) Improvements in or relating to hydraulic shock absorbers, with parallel connected gas springs
CN110486406B (en) Hydraulic damper
EP0774091A1 (en) Linear motor valve
WO2017073218A1 (en) Damper and method for assembling damper
US6135250A (en) Hydropneumatic vibration damper of variable damping force
US11761508B2 (en) Variable-damping hydraulic shock-absorber for a vehicle suspension
US6273224B1 (en) Shock absorber mounted electromagnetically operated damper valve
US6322058B1 (en) Air suspension apparatus
CN112377553B (en) Damper assembly and housing therefor

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee