HK1074662A - Hydraulic dampers with pressure regulated control valve and remote pressure adjustment - Google Patents

Description

Hydraulic damper with pressure regulating control valve and remote pressure regulation

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Technical Field

The present invention relates to hydraulic dampers that may be used alone or as part of a shock absorber, front fork or other suspension system.

Background

Dampers are used in conventional shock absorbers, front forks and other suspension systems to cushion or absorb shocks or forces applied to the suspension system. For example, conventional dampers include a tubular housing defining a sealed chamber. An incompressible hydraulic fluid is disposed within the cavity of the housing. One end of the piston rod on which the piston is seated is also disposed in the cavity. A bore extends through the piston such that the piston can slide within the chamber of the housing as hydraulic fluid passes through the bore.

When a compressive force is applied to the damper, such as when a car with a shock absorber strikes a bump, the force then attempts to drive the piston rod into the cavity of the housing. This force is partially absorbed by using it to compress the hydraulic fluid passing through the orifice. When a rebound force is applied to the damper, for example by applying a spring, the damper adjusts the rebound force to return the piston rod to its original position by requiring a return flow of hydraulic fluid through a hole in the piston.

While conventional dampers provide a suspension system with some degree of damping, conventional dampers have significant drawbacks. For example, the damping characteristics of conventional dampers are associated with a continuous restriction of hydraulic fluid flow through the bore extending through the piston. Since this variable does not vary along the stroke of the piston rod, the damping properties are substantially constant independent of the applied force or the position of the piston rod. As a result, minimal damping performance is achieved. That is, what is needed in the art is a damper for a suspension system that automatically adjusts the damping characteristics throughout the range of piston motion to effectively cushion based on changing operating and road conditions.

While attempts have been made to make adjustable dampers, such dampers are less effective, difficult and expensive to manufacture, and have less optional adjustment permitted based on the needs of the use and conditions.

Drawings

Various embodiments of the present invention will be described below with reference to the accompanying drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope.

FIG. 1 is a cross-sectional side view of an embodiment of a damper;

FIG. 2 is an exploded perspective view of the distal end of the piston rod of the damper depicted in FIG. 1;

FIG. 3 is an enlarged cross-sectional side view of the assembly shown in FIG. 2 in an assembled state;

FIG. 4 is a cross-sectional side view of the damper shown in FIG. 1 with the control valve in an open state;

FIG. 5 is a cross-sectional side view of the damper shown in FIG. 4 with the piston rod fully advanced into the housing;

FIG. 6 is a cross-sectional side view of the damper shown in FIG. 5 with the piston rod fully advanced into the housing;

FIG. 7 is a cross-sectional side view of the damper shown in FIG. 6 with the piston rod retracted out of the housing;

FIG. 8 is a cross-sectional side view of a spring biasing a floating piston on the distal end of the damper shown in FIG. 1;

FIG. 9 is a cross-sectional side view of a balloon disposed on the distal end of the damper shown in FIG. 1;

FIG. 10 is a cross-sectional side view of a deformable diaphragm disposed at an end of the damper shown in FIG. 1;

FIG. 11 is a boundary line between hydraulic fluid and compressible gas disposed on the distal end of the damper shown in FIG. 1;

FIG. 12 is a cross-sectional side view of an alternative embodiment having an adjustable piston;

FIG. 13 is a cross-sectional side view of the damper shown in FIG. 12 with the adjustment piston moved to a second position;

FIG. 14 is a schematic view of a remote pressure regulated damping system;

FIG. 15 is a cross-sectional side view of an alternative embodiment of a damper having a fixed control valve assembly;

figure 16 is a cross-sectional side view of the damper shown in figure 15 with the piston rod moved into the housing;

FIG. 17 is a cross-sectional side view of the damper shown in FIG. 16 with the piston rod fully advanced into the housing;

FIG. 18 is a cross-sectional side view of the damper shown in FIG. 17 with the piston retracted out of the housing;

FIG. 19 is a cross-sectional side view of a dual tube damper;

FIG. 20 is a cross-sectional side view of the dual tube damper shown in FIG. 19 with the piston rod fully advanced into the inner tube;

FIG. 21 is a perspective view of a shock absorber;

FIG. 22 is a front elevational view of the shock absorber illustrated in FIG. 21;

FIG. 23 is a side view of the shock absorber shown in FIG. 21;

FIG. 24 is a cross-sectional side view of the shock absorber shown in FIG. 21;

FIG. 25 is a cross-sectional side view of the shock absorber shown in FIG. 24 taken along line 25-25;

FIG. 26 is an enlarged cross-sectional side view of a second end of the stem (stem) of the shock absorber shown in FIG. 24;

FIG. 27 is an enlarged cross-sectional side view of the gas capacity regulator assembly of the shock absorber shown in FIG. 24;

FIG. 28 is a cross-sectional side view of an alternative embodiment of a damper having a base valve assembly;

FIG. 29 is an enlarged cross-sectional side view of the base valve assembly illustrated in FIG. 28;

FIG. 30 is a cross-sectional side view of the damper shown in FIG. 28 with the piston rod advanced into the housing;

FIG. 31 is a cross-sectional side view of the damper shown in FIG. 30 with the piston rod retracted from the housing;

FIG. 32 is a cross-sectional side view of the alternative embodiment of the damper shown in FIG. 28 with the floating piston replaced by a deformable diaphragm;

FIG. 33 is a cross-sectional side view of the alternative embodiment of the damper shown in FIG. 28 with the floating piston replaced by an alternative base valve assembly;

FIG. 34 is a heightwise cross-sectional side view of a front wheel fork having a case incorporating the damper of the present invention;

FIG. 35 is a heightwise cross-sectional side view of the front fork illustrated in FIG. 34 with the piston rod advanced into the upper tube;

FIG. 36 is a heightwise cross-sectional side view of the front fork illustrated in FIG. 34 with the cartridge removed;

FIG. 37 is a heightwise cross-sectional side view of the front fork illustrated in FIG. 34 with the piston rod advanced into the upper tube;

FIG. 38 is a heightwise cross-sectional side view of the front fork illustrated in FIG. 36 with the piston rod advanced into the upper tube;

FIG. 39 is a cross-sectional side elevational view of the front fork with the fixed base valve in the upper tube; and

FIG. 40 is a side elevational view in cross section of the front fork illustrated in FIG. 39 with the piston rod retracted from the upper tube.

Detailed Description

The present invention relates to hydraulic dampers that may be used alone or as part of a shock absorber, front fork or other suspension system. Such dampers may be used in connection with all types of vehicles or machinery where control of suspension movements and/or vibrations is required. Examples of vehicles in which dampers may be used include bicycles, electric vehicles, automobiles, ground moving vehicles, snowmobiles, airplanes, and the like.

One embodiment of a damper 10 incorporating features of the present invention is depicted in FIG. 1. Damper 10 includes a housing 12 having an inner surface 14 bounding a cavity 16. Housing 12 includes a cylindrical sidewall 18 extending between a proximal end 20 and an opposite distal end 22. An end wall 24 is formed on distal end 22 of side wall 18. A bracket 30 having an aperture 32 extending therethrough is formed in end wall 24 to selectively couple damper 10 to a structure. In alternative embodiments, the bracket 30 may be replaced by any conventional attachment structure.

A cap 26 is removably threaded or otherwise connected to the proximal end 20 of the sidewall 18. The cover 26 has a passageway 28 extending centrally therethrough to communicate with the chamber 16. Piston rod 34 is slidably disposed within channel 28 to extend to and from chamber 16. Piston rod 34 has an outer surface 36 extending between a proximal end 37 (fig. 2) and an opposite distal end 38. An annular seal 40 extends between cap 26 and piston rod 34 to effectively seal the connection so that piston rod 34 is free to slide relative to housing 12.

Piston rod 34 includes a base rod 42 and a bolt 44. As shown in fig. 2, the base stem 42 includes an outer surface 45 extending between a proximal end 46 and an opposite distal end 48. Distal end 48 terminates at a distal face 50. A generally L-shaped channel 52 (see fig. 3) extends from distal face 50 to outer surface 45 at distal end 48.

The bolt 44 includes a shaft 56 having a proximal end 58 and an opposite distal end 60. The proximal end 58 of the shaft 56 terminates at a proximal face 64. As shown in fig. 2 and 3, distal end 60 of shaft 56 terminates at distal face 66. The head 70 projects circumferentially and radially outwardly from the shaft 56 at the distal end 60. The head 70 also has a proximal face 72 and an opposite distal face 74. The distal face 74 of the head 70 is closely spaced from the distal face 66 of the shaft 56. A passage 78 extends through shaft 56 from distal face 66 to proximal face 64. A plurality of radially spaced ports 79 extend from the channel 78 to the distal face 74 of the head 70. A nozzle 80 having an opening 82 extending therethrough is removably threaded into passage 78 at distal face 66 of shaft 56. As will be described in greater detail below, the nozzle 80 may be replaced with other nozzles having different sized openings. Alternatively, the nozzle 80 may be replaced with a plug so that the only access to the passage 78 is through the through port 79 at the distal end 60 of the shaft 56.

One or more deformable metal spring shims 84 are mounted to distal face 74 of head 70 to surround shaft 56 and cover the opening to port 79. Shim 84 is held in place by a C-clip 86, which C-clip 86 mates with a groove on shaft 56 at the distal end of shim 84. In an alternative embodiment, the C-clip 86 may be replaced with a washer. The nozzle 80 may then be formed with an outwardly projecting flange at the end. Nozzle 80 is threaded into passage 78 and the flange biases the washer against shim 84 to secure shim 84 in place.

During assembly, distal end 58 of bolt 44 is threaded into distal end 48 of base rod 42 such that passages 52 and 78 are in fluid communication. The combination of passages 52 and 78 is referred to herein as rebound passages 88. In an alternative embodiment, it is understood that the base rod 42 and the bolt 44 may be integrally formed as a single component. Further, the bolt 44 may be replaced with a nut that is threaded onto the distal end of the base rod 42.

As shown in fig. 2, main piston 102, control valve assembly 100 and stop plate 174 are mounted to distal end 38 of piston rod 34. Control valve assembly 100 includes a valve guide 104 and a control valve 106. The master piston 102 has a generally disc-like structure with a proximal face 108, an opposing distal face 110, and a peripheral side 112 extending therebetween. A groove 113 is formed on the peripheral side 112 to receive an annular seal 114 (fig. 3). In the depicted embodiment, the seal 114 includes a deformable O-ring 96, the O-ring 96 biasing the annular band 98 outward. The band 98 typically comprises teflon. Other conventional sealing structures may also be used. It will be noted that in several other views of the piston shown, the annular seal is not shown in the peripheral groove. This helps to make the view clearer. It will be appreciated that in use a seal is provided in each peripheral groove.

A plurality of spaced apart, elongated pressure ports 118 extend through main piston 102 from proximal face 108 to distal face 110. Pressure ports 118 extend from the center of master piston 102 at a substantially constant radius. An elongated shallow pocket 120 is provided on proximal face 108 between each adjacent pressure port 118. Each pocket extends along a radial axis aligned with the center of the master piston 102. Extending from distal face 110 of master piston 102 to each pocket 120 is a corresponding rebound port 122. Rebound ports 122 are disposed radially inward of pressure ports 118. A central opening 116 also extends through the main piston 102.

In the assembled state shown in fig. 3, piston rod 34 passes through central opening 116 of main piston 102 such that main piston 102 surrounds and projects radially outwardly from piston rod 34 adjacent head 70. Seal 114 is biased in sealing engagement against inner surface 14 of side wall 18 to enable main piston 102 to slide freely as piston rod 34 moves within chamber portion 16.

In one embodiment of the present invention, means are provided to enable fluid flow from proximal face 108 through rebound ports 122 to distal face 110 while preventing fluid flow from distal face 110 to proximal face 108. By way of example and not limitation, a plurality of stacked shims 124 surround piston rod 34 and bias distal face 110 of main piston 102. Stacked shims 124 cover the distal opening to rebound ports 122, but not the opening to compression ports 118. A washer 126 is disposed between the head 70 and the stacked shims 124 to provide space for the outer diameter of the stacked shims 124 to flex distally. Such that fluid may be transmitted through rebound ports 122 in a distal direction by flexed shims 124, but is prevented from being transmitted in a proximal direction through rebound ports 122 due to shims 124. Such shims act as one type of one-way check valve during compression movement of piston rod 34 and as a pressure sensitive valve during rebound movement of piston rod 34. That is, the greater the fluid pressure against shims 124 during a rebound stroke, the more shims 124 flex and rebound ports 122 open.

In an alternative embodiment of the means for flowing fluid back to the ejection port 122, it is understood that the shim 124 may be replaced by any alternative one-way check valve design. For example, deformable shims 124 may be replaced with solid washers or flaps that are spring biased against distal face 110 over rebound ports 122. One such example will be described below with reference to fig. 29. It is noted that the various elements and alternative designs disclosed herein incorporate a deformable shim that acts as a one-way check valve. It will be appreciated that each such shim is intended to have a corresponding means of enabling fluid flow in a selected direction, and that such shims may be replaced with alternative one-way check valve designs as discussed above.

As shown in fig. 2, valve guide 104 includes an annular base 130 having a proximal face 132 and an opposing distal face 134. An annular stem 136 projects from distal face 132. Stem 136 has an outer diameter less than the outer diameter of base 130. A central opening 138 extends through stem 136 and base 130. In the assembled state shown in fig. 3, piston rod 34 passes through central opening 138 such that distal face 134 of valve guide 104 rests on proximal face 108 of main piston 102. Valve guide 104 only partially covers pockets 120 such that rebound ports 122 remain in fluid communication with pockets 120. It will be noted that valve guide 104 is locked in place by clamping between a shoulder 181 formed on piston rod 34 and main piston 102. In alternative embodiments, it is understood that the valve guide 104 may be directly fixed to or integrally formed with the master piston 102.

As shown in fig. 2 and 3, control valve 106 has an annular peripheral side 144 that extends between an annular distal face 146 and an annular proximal face 148. Distal face 146 has a surface area that is less than the surface area of proximal face 148. In one embodiment, the aspect ratio of the surface area of distal face 146 to the surface area of proximal face 148 is between about.3 and.6, with about 3 to about.4 being more preferred. In general, the control valve 106 includes an annular collar 150 having an inner surface 152. An annular flange 154 projects radially inwardly from the inner surface 152 of the proximally located collar 150. Flange 154 has a proximal face 155 terminating at an inner surface 157. A central opening 156 extends through collar 150 and flange 154.

In the assembled state, piston rod 34 is slidably received in central opening 156 such that control valve 106 slidably mates with valve guide 104. In particular, in the position depicted in fig. 3, the collar 150 of the control valve 106 surrounds the base 130 of the valve guide 104. An annular groove 158 is formed on the inner surface 152 of the collar 150 and receives an annular first seal 160. First seal 158 biases base 130 of valve guide 104 to form a slidable sealing engagement between collar 150 and base 130.

Flange 154 of control valve 106 surrounds stem 136 of valve guide 104. An annular groove 162 is formed on the inner surface of flange 154 and receives an annular second seal 164. Second seal 164 biases stem 136 of valve guide 104 to form a slidable sealing engagement between flanges 154 and 136. It must be noted that in the other several views showing the control valve assembly 100, the first seal 160 and the second seal 164 are not shown in their respective grooves. This helps to make the view clearer. However, it will be appreciated that in use, the seals 160 and 164 are disposed in corresponding grooves in each control valve assembly 100.

An annular groove 166 is also formed on the inner surface of the control valve 106 between the first and second seals 158, 164. The slot partially circumscribes a valve chamber 170 formed between control valve 106 and valve guide 104, and is sealed by first seal 158 and second seal 164. Disposed within valve cavity 170 is a compressed gas such as air. In one embodiment, air is trapped within valve cavity 170 at a first pressure, i.e., air pressure, above control valve 106 is received over valve guide 104. In alternative embodiments, it is understood that a resilient compression member, such as a spring or compressible material, may also be disposed within valve cavity 170 to bias between valve guide 104 and control valve 106.

As shown in fig. 2, the annular brake plate 174 has a distal side 176 and an opposing proximal side 178. A central opening 180 and a plurality of radially spaced ports 182 extend through the stop plate 174 between the opposing sides 176 and 178. As shown in fig. 3, the distal end 48 of the base stem 42 passes through the central opening 180 such that the stop plate 174 is captured between the shoulder 181 of the base stem 42 and the valve guide 104.

The stop plate 174 serves as a stop for the control valve assembly 100. In particular, the control valve assembly 100 operates in different states between the open and closed positions. In the closed position shown in fig. 3, distal face 146 of control valve 106 biases against proximal face 108 of main piston 102 to cover the proximal opening to compression port 118. However, a portion of the pockets 120 of the master piston 102 are not covered by the control valve 106 or the valve guide 104 such that open fluid communication is provided to the rebound ports 122 to the pockets 120. As described in detail below, it may be noted that when control valve 106 is in the closed position, valve chamber 170 collapses to have a first volume.

As shown in fig. 4, control valve assembly 100 is in a fully open position. In this configuration, control valve 106 slides proximally relative to valve guide 104 such that proximal face 148 of control valve 106 is biased against stop plate 174, thereby limiting further proximal movement of control valve 106. In this open position, control valve 106 is disengaged from main piston 102 such that fluid is free to pass through compression port 118 and fluid passage 167 formed between control valve 106 and main piston 102. It may also be noted that in the open position, distal face 155 of flange 154 of control valve 106 is spaced from proximal face 132 of base 130 of valve guide 104, thereby expanding valve chamber 170 to have a second volume greater than the first volume. The pressure in valve chamber 170 is greater in the collapsed state than in the expanded state. As such, the pressure within valve chamber 170 has a natural tendency to urge control valve 106 into the open position under a force corresponding to the relative pressure within valve chamber 170.

Returning to fig. 1, floating piston 184 is slidably disposed within cavity 16 at the distal end of piston rod 34. Floating piston 184 has a peripheral side 186 extending between a distal face 188 and an opposite proximal face 190. A seal 192 is disposed on the peripheral side 186. Seal 192 biases inner surface 14 of sidewall 18 of housing 12 in sealing engagement to allow floating piston 184 to selectively slide within cavity 16, but substantially excludes fluid or gas from passing through or around floating piston 184.

Floating piston 184 divides chamber 16 into a distal compartment 196 and a proximal compartment 198. Chambers 196 and 198 each change relative size as floating piston 184 slides within cavity 16. A chamber disposed in distal compartment 196 compresses a gas, such as air, while a hydraulic fluid is disposed in proximal compartment 198. As used in the claims and the specification, the term "hydraulic fluid" is intended to include all types of fluid that can transmit hydraulic pressure. While hydraulic fluids are generally considered to be incompressible, it is understood that hydraulic fluids may emulsify or have entrained gas, thereby making them somewhat compressible.

The gas in proximal compartment 196 is set at a second pressure that is less than the first pressure of the gas within valve chamber 170. Accordingly, in the rest position shown in fig. 1, in which piston rod 34 is withdrawn from chamber 16, control valve 106 is in the closed position. That is, the pressure in distal compartment 196 is transmitted through the hydraulic fluid within floating piston 184 and proximal compartment cavity 198 to collapse valve cavity 170 and move valve guide 106 to the closed position.

In summary, control valve 106 closes due to the reactive forces exerted by the hydraulic fluid on distal side 134 of valve guide 104 and on proximal face 148 of control valve 106. Although not required, it has been empirically determined that if the surface area of the distal side 134 of the valve guide 104 is at least 50% over the chamber, preferably at least 60%, and more preferably 70% over the surface area of the proximal face 148 of the control valve 106, the control valve assembly 100 operates more efficiently under applied pressure to move between the open and closed positions.

During operation, when a force is applied to proximal end 37 of piston rod 34 that is greater than the force holding control valve assembly 100 in the closed position, piston rod 34 with main piston 102 and control valve assembly 100 begins to move distally within chamber 16. In particular, as shown in fig. 4, as piston rod 34 moves distally within bore 16, hydraulic fluid in proximal compartment 198 passes through compression port 118 and pushes distal face 146 of control valve 106, thereby causing control valve 106 to slide at least partially to the open position.

Control valve assembly 100 measures the flow rate of hydraulic fluid through compression port 118 during advancement of main piston 102. The extent to which control valve 106 slides distally depends in part on the speed and magnitude of the force applied to piston rod 34. For example, if a large force is rapidly applied to piston rod 34, i.e., a sharp-speed bump force, control valve assembly 100 rapidly moves to the fully open position due to the high pressure generated in proximal chamber 198 and applied to distal face 146 of control valve 106. Hydraulic fluid is thus free to pass through compression ports 118 and around control valve 106, thereby allowing piston rod 34 to be quickly and easily advanced with chamber 16. In this way, the impact of the initial force on piston rod 34 is quickly absorbed by the movement of piston rod 34. In contrast, if a small force is gradually applied to piston rod 34, control valve 106 is only partially moved to the open position such that flow passage 167 remains partially restricted. This restriction of flow passage 167 reduces the flow of hydraulic fluid through compression ports 118, which reduces the movement of master piston 102 within chamber 16.

As shown in fig. 5, as more piston rod 34 enters proximal compartment 198, piston rod 34 displaces a corresponding volume of hydraulic fluid therein. Since the hydraulic fluid is not significantly compressed, the hydraulic fluid causes floating piston 184 to slide distally and compress the gas with distal compartment 196. As the gas pressure increases in distal compartment 196 and the fluid pressure increases in proximal compartment 198, the fluid pressure begins to collapse valve chamber 170, thereby moving control valve 106 to the closed position. When control valve 106 is moved to the closed position, the constriction of flow passage 167 makes it more difficult for hydraulic fluid to pass through. Accordingly, the further piston rod 34 is advanced into cavity 16, the greater the resistance applied to piston rod 34.

As shown in fig. 6, piston rod 34 moves further into chamber 16 as control valve assembly 100 returns to the closed position. This occurs when a sufficient length of piston rod 34 enters proximal compartment 198 such that hydraulic fluid pressure tends to move control valve assembly 100 into the closed position, thereby precluding fluid from passing through compression ports 118, greater than the external force applied to piston rod 34, which tends to cause hydraulic fluid to move the control valve into the open position.

As will be seen below, in alternative embodiments, the volume of distal compartment 196 and the initial pressure therein may optionally be adjusted. The initial pressure and the volume of distal compartment 196 have some effect on damping. For example, by increasing an initial pressure within distal compartment 196, an increased force is initially applied by the hydraulic fluid to maintain control valve assembly 100 in the closed position. As such, a greater force needs to be applied to piston rod 34 to initially move control valve assembly 100 to the open position.

In addition, as piston rod 34 is moved into proximal compartment 198, having a higher initial pressure within distal compartment 196 causes control valve assembly 100 to close earlier. That is, the gas pressure in distal compartment 196, and thus the hydraulic fluid pressure within proximal compartment 198, increases exponentially as the volume of distal compartment 198 is compressed. The increase in pressure is based on the compression ratio of distal compartment 198, i.e., the compression ratio of the initial volume of distal compartment 198 and the final volume of distal compartment 198 as piston rod 34 is advanced into cavity 16. For example, if the starting volume of distal compartment 198 is 100cc and the final volume is 25cc, the compression ratio is 4: 1. As a result, the gas pressure in the final volume, and thus the hydraulic fluid pressure, is 4 times the gas pressure in the initial volume. Pressure continues to increase exponentially as the volume of distal compartment 198 decreases through compression.

It will be appreciated that the initial volume of distal compartment 198 may be adjusted individually from the initial pressure therein to achieve the damping properties, respectively. For example, in a first embodiment, the initial volume of distal compartment 198 may be 100cc, while the initial volume in a second embodiment is 75 cc. Assuming that the initial gas pressure in each embodiment is the same, the same initial force is applied to the control valve 100, as described above. However, for the same movement of piston rod 34 in each embodiment, the compression ratio is greater for the second embodiment because the initial volume is smaller. Thus, the rate of increase in pressure and the resulting damping force are greater in the second embodiment relative to the first embodiment.

In view of the foregoing, during the compression movement of the main piston 102, an almost infinite combination of pressures may be applied to the control valve assembly 100 due to: the movement of piston rod 34 and the resulting pressure change within chamber 16; the resulting varying impact load and resulting pressure within the chamber on each side of the master piston 102; and the pressure variably generated across the stroke of piston rod 34 on distal face 134 of valve guide 104 and on distal face 148 of control valve 106.

The resulting measurement of hydraulic fluid flowing through pressure port 118 on main piston 102 by control valve assembly 110 during compression movement of main piston 102 thus produces a damping effect: position sensitivity as a result of the position of piston rod 34 within proximal lumen 138; variable position and load sensitivity depending on the position of master piston 102, the speed/force of the impact input, and the pressure within distal compartment 196; and adjustable in position and/or load by varying the pressure and volume within distal compartment 196.

As shown in fig. 7, during rebound when piston rod 34 is withdrawn from chamber 16, the pressure exerted by the hydraulic fluid keeps control valve assembly 100 closed, thereby preventing hydraulic fluid, now adjacent control valve 106, from passing through compression ports 118. Instead, hydraulic fluid flows through one of three rebound paths. In the first path, hydraulic fluid enters rebound channel 88 on the proximal side of brake plate 174, passes through piston rod 34 centrally along rebound channel 88, and then exits through distally flexing shim 84. In the second rebound path, hydraulic fluid within the rebound passages 88 flows not out of the through ports 78 but out of the through nozzles 80. In the third rebound path, hydraulic fluid is transmitted around the exterior of the control valve 106 and into the pocket 120 of the master piston 102. The hydraulic fluid then exits through rebound ports 122 by distally flexing shims 124.

By adjusting the stiffness and/or number of shims 84, 124 and the size of openings 82 in nozzle 80, hydraulic fluid may flow through one, two, or all three rebound paths simultaneously. For example, by making shim 124 stiffer than shim 84, hydraulic fluid flows through nozzle 80 with only a small spring-back force. At higher rebound forces, hydraulic fluid may flow through the first and second rebound paths or through all three rebound paths.

The rebound force typically generated by the opposing spring is generally greatest when piston rod 34 is fully inserted into cavity 16 (fig. 6) and begins to move in the rebound direction. In this way, all of the rebound path may initially be used as piston rod 34 to begin retraction. However, as piston rod 34 continues to move in the rebound direction, one or more rebound paths may close, thereby slowing rebound as piston rod 34 approaches the fully retracted position. As will be discussed below with respect to alternative embodiments, rebound passages 88 can also be optionally restricted or closed to allow manual operation of hydraulic fluid based on operating parameters.

As described above, a compressible gas is sealed within distal compartment 196 such that piston rod 34 is transferred into cavity 16 by compression of the gas and at least partially controls the operation of control valve assembly 100 by creating a varying pressure thereon. It will be appreciated that there are many alternative ways of achieving these same functions.

For example, as shown in fig. 8, a resiliently compressible member 246 is disposed within distal compartment side 196. Member 246 extends between floating piston 184 and distal end wall 24. Although member 246 is shown as a coil spring, in alternative embodiments member 246 may comprise other forms of mechanical springs or blocks of resiliently compressible material such as rubber or polymeric foam. As hydraulic pressure increases in proximal cavity 198, floating piston 184 slides distal resilient compression member 246. In this regard, the compression spring 246 acts similarly to compressed gas.

In addition to or independently filling distal compartment 196 with a gas under pressure, it is understood that member 246 may be used. Where member 246 is used independently to provide compression resistance, distal compartment 196 need not be sealed closed within housing 12. For example, an opening depicted by dashed line 248 may be formed through distal end wall 24. Opening 248 facilitates proper displacement of floating piston 184. In other embodiments, it is understood that member 246 need not be disposed within chamber 16, but may be disposed outside chamber 16. For example, a rod may extend from floating piston 184 through distal end wall 24, exiting distal end wall 24, which is connected to component 246 outside of housing 12.

In an alternative embodiment, further shown in fig. 9, a deformable balloon 250 is disposed within the distal end of lumen 16. Bladder 250 communicates with the exterior of the housing through an injection valve 252, such as a Scharder inflation valve. The fill valve 252 allows the bladder 250 to be selectively inflated with gas to a desired pressure. It is noted that bladder 250 may be used with floating piston 184 or separately. That is, floating piston 184 may be eliminated such that hydraulic fluid bears directly against inflated bladder 250 to compress bladder 250. In this embodiment, balloon 250 defines distal compartment 196. Bladder 250 may also be filled with a resilient compressible material such as rubber or polymeric foam.

As shown in fig. 10, the floating piston 184 is replaced by a deformable diaphragm 254. Diaphragm 254 is mounted to inner surface 14 of sidewall 18 of housing 12 to divide chamber 16 into distal compartment 196 and proximal compartment 198. Fill valve 256 is formed in sidewall 18 and allows distal compartment 196 to be filled with compressed gas to a desired pressure. Again, as piston rod 34 is advanced into cavity 16, the hydraulic fluid presses against diaphragm 254 to cause it to flex distally, thereby causing gas within distal compartment 196.

It is understood that in other embodiments, a different mechanical barrier is not required. For example, as shown in fig. 11, the cavity 16 is filled with a gas 260, such as air, and a hydraulic fluid 262. A boundary line 264 is formed therebetween. As piston rod 34 enters chamber 16, hydraulic fluid 262 compresses air 260. However, in some uses, this embodiment does not allow the gas and hydraulic fluid to mix or emulsify well within the chamber 16 and reduce operational attributes.

A number of different damper embodiments are described below, wherein like components are identified with like reference numerals. In one embodiment of the present invention, means are provided for selectively adjusting the size of distal compartment 196. By way of example, shown in fig. 12 is a damper 210. Damper 210 is substantially identical to damper 10, except that damper 210 includes an adjusting piston 212 disposed within chamber 16 at the distal end of floating piston 184. The adjustment piston 212 includes a periphery 214 having a seal 216 formed thereon. The seal 216 is biased in sealing engagement against the inner surface 14 of the sidewall 18 of the housing 12 such that the adjustment piston 212 selectively slides within the cavity 16 without allowing fluid to pass therethrough or around.

A sleeve 218 is centrally mounted on the adjustment piston 212. The sleeve 218 has a threaded bore 220 that is open to the distal end. In an alternative embodiment, it is understood that threaded bore 220 may be formed directly in the distal face of adjustment piston 212.

A handle 222 is mounted to the housing 12. The handle 222 has a first end with an enlarged head 224 formed thereon. The head 224 is partially exposed to the exterior of the housing 12 to allow for optional, manual rotation of the head 224. A threaded shaft 226 is formed at an opposite second end of the handle 22. A threaded shaft 226 is threadably engaged with the bore 220 on the piston 212. Accordingly, as shown in fig. 12, 13, adjustment piston 212 is selectively advanced and retracted within the distal end of lumen 16 by selecting an optional rotatable head 224 of handle 22.

In this embodiment, distal compartment 196 is defined between adjustment piston 212 and floating piston 184. Distal compartment 196 becomes smaller by manually pushing adjustment piston 212 toward floating piston 184. By making distal compartment 196 smaller, the air pressure may increase therein, the rate at which the pressure increases in proximal compartment 198 increases as floating piston 184 moves distally. Alternative embodiments of the means for selectively adjusting the distal compartment are described below.

Fill valve 228 is also mounted to housing 12 to communicate with distal compartment 196. As previously mentioned, the fill valve 228 may comprise a conventional air valve such as used on a vehicle or bicycle tire. Thus fill valve 228 may be used to increase or decrease the pressure of gas within distal compartment 196. For example, air may be added or removed from distal compartment 196 to selectively increase or decrease the air pressure therein. Again, as previously described, air pressure affects the operation of control valve 100 and the movement of piston rod 34. Accordingly, adjusting the piston 212 and the fill valve 228 allows an end user to selectively adjust the damping properties of the damper 210 based on current or desired operating parameters.

In one embodiment of the present invention, a fluid pressure for regulating hydraulic fluid within proximal chamber 198 of damper 10 is provided. By way of example, and not limitation, one embodiment of a pressure regulated damping system 232 is depicted in FIG. 14. The damping system 232 includes means for providing compressed air. Examples of such means include a gas source 234, which may include a compressor or tank holding compressed gas. Damping system 232 further includes a pressure regulator 235 and one or more dampers 10. One port 238 is disposed in fluid communication with distal compartment 196 of each damper 10. The supply tube 240 provides gas communication between the gas source 234 and the pressure regulator 235. In turn, a supply line 242, such as a tube or any other form of conduit, provides gaseous communication between pressure regulator 235 and distal compartment 196 of each damper 10 through port 238.

Regulator 235 can be manually, electronically, and/or computer controlled to selectively or automatically independently regulate pressure within distal compartment 196 of each damper 10 as the operating environment of damper 10 changes. By increasing the pressure in distal compartment 196, a pressure differential is transmitted across floating piston 184 to increase the fluid pressure of the hydraulic fluid within proximal compartment 198. In turn, increasing the hydraulic fluid pressure regulates the operation of the control valve 100, which adjusts the damping properties of the damper 10. It is understood that the actuator 235 may have a different configuration and be constructed from a plurality of separate components.

As one example of use, one or more dampers 10 may be incorporated into a bumper in an automobile or any other type of vehicle. Rapid remote adjustment of hydraulic fluid pressure can be used to provide optimum suspension performance as road and operating conditions change, e.g., straight versus curved, on-road versus off-road, acceleration versus braking. It will be appreciated that optimum performance will be achieved by simultaneously and individually adjusting the hydraulic fluid pressure in each damper 10 on the vehicle.

To facilitate automatic damping adjustment, one or more sensors 243, such as gyroscopic sensors or other motion sensitive sensors, may be mounted to the vehicle and in electrical communication with a Central Processing Unit (CPU) 244. CPU 244 may be separate from or form a part of regulator 235. Based on input from one or more sensors 243, CPU 244 may control regulator 235 to adjust the air pressure and resulting hydraulic fluid pressure in one or more dampers 10 on the vehicle accordingly.

As an alternative to automatic adjustment, a manual input mechanism 245, such as a switch or control panel, may be electrically connected to CPU 244. The inputs provided to manual input mechanism 245 may be used to set the hydraulic fluid in each damper 10 to a predetermined valve.

The use of pneumatic pressure is merely one example of a fluid pressure for remotely adjusting the hydraulic fluid within proximal chamber 198 of damper 10. As an alternative embodiment, the spring 246 of FIG. 8 may be disposed between the floating piston 184 and the adjusting piston 212 of FIG. 12. In turn, a motor or other form of gear mechanism is connected to the handle 222 of FIG. 12. The central processing unit 244 is electrically connected to the motor such that, based on a sensor or manual input signal, the motor adjusts the compression of the spring 246 to remotely adjust the hydraulic fluid pressure within the damper 10.

It will be appreciated that a variety of different systems may be used to remotely adjust the fluid pressure of the hydraulic fluid within the damper 10 by alternatively adjusting the pressure applied to the floating piston 184 or one of the alternative methods discussed herein.

In view of the foregoing, the suspension of a vehicle may be controlled by providing a vehicle having a suspension system including at least one pressure-regulated damper; and automatically or optionally during operation of the vehicle, transferring gas to or extracting gas from the at least one damper to automatically or optionally control suspension performance properties of the at least one damper. Such suspension control may be performed during movement of the vehicle.

Similarly, suspension control may be achieved by automatically or optionally varying the fluid pressure of the hydraulic fluid within the at least one damper during operation of the vehicle to automatically or optionally control suspension performance properties of the at least one damper, the automatic or optional variation based on automatic sensor signals or manual input signals.

Shown in fig. 15 is an additional alternative embodiment of a damper 270 incorporating features of the present invention. Damper 270 includes a housing 12 defining a cavity 16. Cavity 16 is separated by floating piston 184 into a distal compartment 196 and a proximal compartment 198, which contain compressed air and hydraulic fluid, respectively. Again, floating piston 184 may be replaced with any of the alternatives previously described.

A piston rod 272 slidably extends to the proximal end of the housing 12. The piston rod 272 includes a base rod 278 and a bolt 280. Bolt 280 is threaded onto the distal face of base rod 278 to secure master piston 102 therebetween. A seal 114 is mounted to the periphery of the main piston 102 and forms a slidable sealing biased fit against the inner surface 14 of the side wall 18.

A first shim 282 is secured between enlarged head 281 of bolt 280 and distal face 110 of piston 274. First shim 282 biases distal face 110 of piston 274 to cover the distal opening to rebound ports 122. Second shim 284 is disposed between the distal end of base rod 278 and proximal face 108 of piston 274. Second shim 284 biases proximal face 108 of piston 274 to cover the proximal opening of compression port 118. However, second shim 284 covers only a portion of pocket 120 leading to rebound port 122. As previously discussed with respect to shims 124 in FIG. 3, shims 282 and 284 act as one-way check valves that control the direction of flow through rebound ports 122 and compression ports 118, respectively. The alternatives discussed previously with respect to shims 124 may also be applied to shims 282,284, as well as the deformable shims disclosed in other embodiments of the present invention.

In contrast to damper 10, in which control valve assembly 100 is mounted to a movable piston rod, in this embodiment control valve assembly 100 is mounted to an auxiliary piston 274 disposed within proximal chamber 198 between piston rod 272 and floating piston 184. The secondary piston 274 has a similar structure to the primary piston 102, and as such like reference numerals are used to identify like components. It should be noted, however, that the auxiliary piston 274 and the control valve assembly 100 are rotated 180 degrees relative to the corresponding structure in the damper 100. In this way, the proximal and distal orientations become reversed.

The auxiliary piston 274 is held in place by clips 292 which are received in slots on the inner surface of the side wall 18 to bias the opposite sides of the auxiliary piston 274. In an alternative embodiment, the clips 292 may be further separated from each other to allow some sliding of the auxiliary piston 274 in the longitudinal direction. In further embodiments, the secondary piston 274 may be integrally formed with the housing 12 to eliminate the need for the seal 114 and the clip 292. Shaft 288 extends through auxiliary piston 274 and controls valve assembly 100 to secure the two components together. Shim 124 biases against proximal face 110 of secondary piston 274 and is secured thereto by head 290 of shaft 288 and washer 126. A stop plate 174 is mounted on the distal end of shaft 288 to control the distal movement of the control valve 106. The combination of the auxiliary piston 274, the control valve 100 and the brake plate secured together by the shaft 288 is referred to herein as a base valve 286.

As shown in fig. 16, as piston rod 272 enters distal compartment 198 of cavity 16, the hydraulic fluid causes second shim 184 to flex proximally to allow the hydraulic fluid to pass through compression ports 118 of main piston 102. At the same time, the hydraulic fluid also moves the control valve 106 of the control valve assembly 100 into an at least partially open state such that the hydraulic fluid may pass through the compression portion 118 of the auxiliary piston 274. The hydraulic fluid then pushes floating piston 184 distally, thereby compressing the gas within distal compartment 196.

As shown in FIG. 17, when the compression movement of piston rod 272 stops within chamber 16, the fluid pressure within proximal chamber 198 collapses valve chamber 170, thereby moving control valve 106 into the closed position. As shown in fig. 18, during a rebound stroke, hydraulic fluid is transmitted through second piston 274 by flowing through pockets 120 and out through rebound ports 122 by proximally flexing shims 124. Similarly, hydraulic fluid flows out through rebound ports 122 by passing through pockets 120 through main piston 102 and by distally flexing shims 282.

Shown in fig. 19 is an additional embodiment of a damper 300. Damper 300 includes a double tube housing 302. In particular, the housing 302 includes a distal cover 304 and an opposing proximal cover 306. An outer tube 308 extends between caps 302 and 304 and is secured thereto. Disposed within outer tube 308 is inner tube 310, which also extends between opposing caps 304 and 306. Inner tube 310 has an inner surface 312 defining an inner chamber 314. An outer chamber 316 is defined between the outer surface of the inner tube 310 and the inner surface of the outer tube 308. Inner chamber 314 communicates with outer chamber 316 through port 318.

The inner chamber 314 is filled with hydraulic fluid. An inflatable bladder 320 is disposed within the outer chamber 316. The bladder 320 is optionally inflated through an injection valve 322 projecting through the outer tube 308. Base valve 286 is disposed within the distal end of inner chamber 314 as previously described with respect to damper 270 in fig. 15-18. However, in this embodiment, shaft 288 is used to secure base valve 286 directly to distal cap 304. It is understood that alternative mounting methods may be used to secure the base valve 286 within the inner tube 310. As with damper 270, already discussed, a piston rod 272 having a main piston 102 is slidably disposed within inner chamber 314.

As shown in fig. 20, damper 300 operates similarly to damper 270. In particular, as the piston rod enters the interior chamber 314, the control valve 106 moves to the open position and hydraulic fluid flows through the compression ports 118 on the main piston 102 and the auxiliary piston 274. As fluid flows past the auxiliary piston 274, hydraulic fluid enters the outer chamber 316 through the port 318, which compresses the bladder 320 at the port 318. The hydraulic fluid continues to compress the bladder 320 until the piston rod 272 is withdrawn. During retraction, hydraulic fluid flows back through the main piston 102 and the auxiliary piston 274 in substantially the same manner as the opposing damper 270 described above. In an alternative embodiment, it is understood that the bladder 320 may be replaced by a floating piston surrounding the inner tube 310 and sliding within the outer chamber 316. In yet another alternative embodiment, the damper 320 may be inverted and the bladder 320 may be removed. In this embodiment, a gas, such as air, is trapped within the outer chamber 316. The hydraulic fluid directly contacts the gas, such as described above with respect to FIG. 11, to optionally compress the gas.

As shown in fig. 21 is one embodiment of a buffer 350 that incorporates features of the present invention. As shown in fig. 22 and 23, the damper 350 includes a piggyback housing 352 including a primary tube 354, a secondary tube 356, and a stem 358 extending therebetween. As shown in fig. 24, the primary tube 354 has an inner surface 430 defining a primary cavity 432, while the secondary tube 256 has an inner surface 437 defining a secondary cavity 438. Returning to fig. 22 and 23, stem 358 has a generally U-shaped configuration extending between a first end 359 and an opposite second end 361. Opening 357 extends through stem 358 at first end 359 for selective attachment to the structure.

The main tube 354 has an outer surface 360 extending between a distal end 362 and an opposite proximal end 364. Distal end 362 of primary tube 354 is threaded into first end 359 of stem 358. Proximal end cap 366 is threaded into proximal end 364 of parent tube 360. An annular distal spring retention collar 368 is adjustably threaded onto distal end 362 of primary tube 360.

The piston rod 370 has a distal end 372 (fig. 24) and an opposite proximal end 374. A bracket 376 having an opening 378 extending therefrom is threaded onto the proximal end 374 of the piston rod 370. An annular proximal spring retention collar 380 is mounted to the bracket 376. A coil spring 382 extends between the distal spring retention collar 368 and the proximal spring retention collar 380. The tension on spring 382 is optionally adjustable by adjusting distal spring retention collar 368 along the length of primary tube 354.

A bottom-out cushion (bottom-out cushion)382 surrounds the spring rods 370 between the proximal end cap 366 and the proximal spring retention collar 380. The pad 382 is made of a resiliently deformable material such as rubber or a polymeric foam material.

As shown in FIG. 24, the piston rod 370 includes a tubular base rod 384 and the bolt 44, as previously discussed with respect to the damper 10. The base rod 384 has an inner surface 390 defining a channel 392 that extends longitudinally between the distal end 386 and an opposite proximal end 388. The bolt 44 is threaded onto the distal end 386 of the base rod 384. A port 394 extends through base rod 384 to provide fluid communication between primary chamber 432 of main tube 354 and passage 178. Pin 396 is slidably disposed within channel 392 of base rod 384. The pin 396 has a tapered front end 398 disposed on the distal end. The forward end 398 is configured to complementarily fit within the proximal opening of the passage 78 of the bolt 44. As a result, pin 396 may be used to selectively restrict or close fluid communication between primary cavity 432 and passage 78 by advancing or retracting pin 396 within base rod 384.

Bracket 376 has a distal face 410 with a bore 412 recessed therein. The channel 400 extends across the bracket 376 to intersect the aperture 412. Bracket 376 is threaded onto base rod 384 such that pin 396 extends downwardly through hole 412 and partially into passage 400. An adjuster 414 is adjustably disposed within the channel 400. The adjuster 414 includes a shaft 416 having a distal portion 418 threadably positioned within the channel 400 of a bracket 376, a substantially frustoconical transition portion 420, and a substantially cylindrical central portion 422 formed therebetween. The adjuster 414 also includes an optional removable handle 424. Alternate rotation of the handle 424 advances and retracts the adjuster 414 within the channel 400. As adjuster 414 is advanced within passage 400, frustoconical transition portion 420 biases the distal end of pin 396, causing pin 396 to advance toward bolt 44, thereby restricting or closing the proximal opening to passage 78. Conversely, when the adjuster 414 is withdrawn, the pin 396 is lowered, thereby opening the fluid path to the channel 78. An optional adjustment system may also be used to move pin 396.

The main piston 102, control valve assembly 100 and stop plate 174 are mounted to the distal end of piston rod 370. These components are substantially the same as previously discussed with respect to damper 10 and operate in the same manner. The only difference is that control valve assembly 100 of the embodiment shown in fig. 24 has a slightly different configuration of valve cavity 170. This is due to the different slots formed on the valve guide 104 and the control valve 106.

Threaded bore 446 is formed at first end 359 of stem 358. Distal end 362 of primary tube 360 is threaded within bore 446. Threaded sleeve 450 protrudes from end surface 451 on second end 361 of stem 358. The distal end of the auxiliary tube 356 is connected to a threaded sleeve 450. Alternative connection methods may also be used to secure the primary tube 360 and the secondary tube 356 to the backpack housing 352, including the use of a single piece forged or cast assembly that includes all of the aforementioned components.

Stem 358 is configured to provide fluid communication between primary chamber 432 of primary tube 360 and secondary chamber 438 of secondary tube 356. In particular, transition passage 448 communicates with bore 446 at first end 359 of stem 358. As shown in fig. 25, first valve chamber 452 and second valve chamber 454 are each bored into stem 358 from second end 361 toward first end 359. First passage 456 extends from first valve chamber 452 to transition passage 448, while second passage 458 extends from second valve chamber 454 to transition passage 448. Bore 460 intersects first valve cavity 452 and extends to end face 451 at second end 361 of stem 358. Bore 462 transversely intersects second valve chamber 454 and central bore 453 to provide fluid communication therebetween. A plug 463 is secured into the opening of bore 462 to prevent fluid from escaping therefrom.

First valve 466 is adjustably disposed within first valve chamber 452. The first valve 466 includes a head 468 having a slot 470 formed on an end to selectively receive a tool for rotating the first valve 466. First valve 466 also has a central body 472 with threads that engage the inner wall of first valve chamber 452. One or more seals 474 surround body 472 and provide sealing engagement with the inner wall of first valve chamber 452. A shaft 474 having a tapered nose 476 projects from the body 472. The tapered nose 476 is configured to selectively engage the opening to the first passage 456. Accordingly, by selectively rotating first valve 466, shaft 474 advances or retracts to selectively restrict or open the opening to first passage 456.

A second valve 480 is adjustably disposed within second valve chamber 454. Similar to the first valve 466, the second valve 480 includes a head 468, a threaded body 466, and a seal 474. Piston 482 is movably disposed in second valve chamber 454 opening to second passageway 458. A spring 484 extends between body 456 and plunger 482 to bias the plunger against opening to second passage 458. Rod 486 extends from piston 482 and passes centrally through spring 484 and freely into the end formed in main body 466. When piston 482 is pushed back, rod 486 is free to retract within main body 466.

By advancing the second valve 480 within the second valve chamber 454, the spring 484 is compressed, thereby providing a greater biasing force against the piston 482. Second passageway 458 is such as to open when a sufficient force is applied to piston 482 to overcome the applied spring force. Accordingly, by selectively adjusting the first valve 466 and the second valve 480, the damping properties may be adjusted for operational adjustments.

Returning to fig. 24, a floating piston 490 may be movably disposed within the second chamber 438. Floating piston 490 divides the enclosed area defined by primary tube 354, secondary tube 356, and stem 358 into a proximal compartment 492 and a distal compartment 493. Again, proximal compartment 492 is filled with hydraulic fluid while distal compartment 493 is filled with compressed air. Other alternative embodiments as previously described may be used in place of or in conjunction with the float valve 490 and the compressible air.

Returning to FIG. 26, a tubular bolt 508 having an enlarged head 509 is threaded into central opening 453 at second end 361 of stem 358. Tubular bolt 508 has an inner surface 510 defining a passage 512. Central opening 453 and passage 512 provide fluid communication between second valve chamber 454 and second chamber 438. Alternative attachment methods may be used in place of bolts 508.

A stationary piston having a similar construction to the piston 102 discussed with respect to damper 10 surrounds the bolt 508 and biases against the inner surface of the sleeve 450. Fixed piston 494 has a proximal face 496 and an opposite distal face 498. Extending between surfaces 496 and 498 are a plurality of damping ports 500 radially separated from one another. A plurality of radially separated pockets 502 are recessed on proximal face 496. Compression ports 504 extend from distal face 498 to each pocket 502.

First shim 514 surrounds bolt 508 and biases proximal face 496. First shim 514 covers the proximal opening of damping port 500, but covers only a portion of pocket 502. Washer 516 surrounds bolt 508 and is disposed between shim 514 of stem 358 and end surface 451. Washer 516 provides a gap between end surface 451 and first shim 514 such that first shim 414 can flex proximally during operation.

Second shim 518 includes bolt 508 and biases against distal face 498 of fixed piston 494. Second shim 518 covers the distal opening of compression port 504, but covers only a portion of the distal opening of damping port 500. Washer 520 is disposed between bolt hole 509 and second shim 518 to allow second shim 518 to flex distally during operation. As previously mentioned, bore 460 extends between first valve chamber and end face 451 of stem 358. Thus, hydraulic fluid flowing through the bore 460 must pass through the fixed passage 494 as it enters the secondary chamber 438.

As shown in fig. 24, a volume adjuster assembly 520 is threaded into the distal end of the auxiliary tube 356. As shown in fig. 27, the volume adjuster assembly 520 includes an annular sleeve 522 having an inner surface 528 and an outer surface 526. The sleeve 522 is threaded onto the distal end of the auxiliary tube 356. Tubular stem 530 is adjustably threaded to sleeve 522. Stem 530 has a proximal end 532 and a distal end 534. Mounted on proximal end 532 of stem 530 to surround and project radially outward therefrom is a piston 536. Piston 536 is secured to stem 530 by a clamp 538 mounted to stem 530 adjacent piston 356. The piston 536 projects outwardly in slidable engagement with respect to the inner surface of the auxiliary tube 356. By selectively rotating stem 530 relative to sleeve 522, stem 530, and thus piston 536, is advanced or retracted relative to sleeve 522. Thus by advancing stem 530 and piston 536, distal compartment 493 becomes smaller. In turn, the rate at which gas is compressed within distal compartment 493, i.e., the compression ratio, is increased.

Chamber 540 is recessed on distal face 541 of stem 530. Channel 542 runs from cavity 540 to proximal end surface 544 of stem 530. Located within cavity 540 in communication with passage 542 is an injection valve 546 through which pressurized gas may be supplied to distal compartment 493. One example of a valve 546 is a Schrader inflation valve. Thus, fill valve 546 may be used to selectively regulate gas pressure within distal compartment 493, thereby regulating the associated damping properties.

It will be appreciated that the buffer 350 operates using similar principles as other embodiments.

Shown in fig. 28 is an additional alternative embodiment of damper 550. Damper 550 has a backpack housing 552 comprising a primary housing 554, a secondary housing 556, and a tubular stem 558 extending therebetween. A sealed tube or other conduit may be substituted for stem 558 to establish fluid communication between primary housing 554 and secondary housing 556. Primary housing 554 is similar to housing 12 discussed above with respect to damper 10, except for connecting stem 558. In addition, as discussed for damper 10, piston rod 34, having main piston 102, control valve assembly 100 and brake plate 174 mounted therebetween, is connected to primary housing 554. Like parts between dampers 550 and 10 are thus identified with like reference numerals.

Secondary housing 556 includes a tubular, cylindrical sidewall 560 extending between a proximal end 562 and an opposite distal end 564. The proximal end terminates at a proximal end wall 563. Volume adjuster assembly 520 is threadably disposed within distal end 564 of secondary housing 556 as previously described with respect to fig. 25. Alternative methods of connecting the volume adjuster assembly 520 may be used. Side wall 560 has an inner surface 566 that defines a secondary chamber 568 extending between proximal end wall 563 and piston 536 of volume adjuster assembly 520. Tubular stem 558 defines a channel 576 extending between primary chamber 16 and secondary chamber 568. Primary chamber 16, secondary chamber 568 and channel 576 of stem 558 combine to form a unitary chamber 578.

Retaining wall 570 projects inwardly from sidewall 560 at distal end 562 of second housing 556. A floating piston 574 is slidably disposed within secondary chamber 568 at the distal portion of retaining wall 570. The floating piston 574 divides the entire cavity 578 into a proximal chamber 580 and a distal chamber 582. Proximal chamber 580 is filled with hydraulic fluid while distal chamber 582 is filled with compressed gas.

Base valve 586 is disposed between retaining wall 570 and proximal end wall 563 of secondary housing 556. Depicted in fig. 29 is an enlarged cross-sectional view of seat valve 586. As depicted therein, base valve 586 is an auxiliary piston 584 having compression ports 118 and rebound ports 122 extending therethrough. Tubular shaft 583 extends through auxiliary piston 584 and beyond the proximal face. Washer 585 encircles shaft 583 to cover the opening to rebound ports 122 while leaving the opening to compression ports 118 open. A retaining flange 587 is threaded onto the proximal end of the shaft 583. A spring 588 extends between retaining flange 587 and washer 585 to bias washer 585 against the opening to rebound ports 583. Washer 585 and spring 588 function as a one-way check valve to regulate fluid flow through rebound ports 122 and are an alternative embodiment to the deformable shims as discussed above for the other embodiments.

The control valve 100 is disposed opposite the distal face of the auxiliary piston 584 and surrounds the tubular shaft 583. The control valve 100 controls the fluid flow through the compression port 118 in substantially the same manner as discussed in the other embodiments. That is, based on the force of the fluid and the pressure of the hydraulic pressure flowing through compression ports 118, control valve 100 moves to some extent between the open position shown in fig. 30 and the closed position shown in fig. 31. However, similar to the prior embodiment, the control valve 100 may be selectively adjusted by application of a spring force.

In particular, collar 589 is inserted into secondary housing 556. Collar 589 surrounds tubular shaft 583 such that an annular spring cavity 591 is formed therebetween. Disposed within spring cavity 591 is an annular first biasing plate 592 disposed against control valve 106 and an annular second biasing plate 593 disposed against portion collar 589. A spring 594 extends between biasing plates 592 and 593 to bias first biasing plate 592 against control valve 106. Posts 595 extend from second bias plate 593 to end cap 596. End cap 596 is configured such that rotation of end cap 596 causes posts 595 to advance into spring cavity 591, thereby further compressing spring 594. As spring 594 is compressed, a greater force is applied to control valve 106, thereby changing operation.

To allow hydraulic fluid to reach the distal side of the control valve 100, a fluid passageway 597 extends through the shaft 583 and communicates with the spring cavity 591 and the cavity 581. A port 598 is formed on the first bias plate 592 such that hydraulic fluid directly contacts the control valve assembly 100. The hydraulic fluid thus assists in the opening and closing of control valve assembly 100 of base valve 586 based on the pressure of the hydraulic fluid. To selectively control the flow of hydraulic fluid into and out of spring cavity 519 and cavity 581, a pin 599 is threaded into fluid passage 597 to selectively restrict fluid passage 597.

Fig. 30 shows the flow path of hydraulic fluid as piston rod 34 advances into chamber 16. Fig. 31 shows the flow path of hydraulic fluid as piston rod 34 is withdrawn from chamber 16.

Shown in fig. 32 is a damper 600 that is substantially identical to damper 550. Damper 600 differs from damper 550 in that floating piston 574 is replaced by a deformable diaphragm 602.

Depicted in fig. 33 is an additional alternative embodiment of damper 610 similar to damper 550. Damper 610 differs from damper 550 in that base valve 586, which contains control valve 100, is replaced with a conventional base valve 612, which does not include control valve 100.

As depicted in fig. 34 and 35 is one embodiment of an inventive damper that can be incorporated into the front fork of a bicycle, electric vehicle, or the like. In particular, fig. 34 depicts a front fork 630 having an upper tube 632 slidably received in a lower tube 634. A spring 633 is provided in the lower tube 634 to resiliently bias the upper tube 632. The spring 633 provides a return force to the damper and can be placed in different positions. Alternative methods of generating the resiliency may be used, such as compressed gas, microcellular foam, and the like. Disposed within upper tube 632 is a tubular cartridge 636 that defines a cavity 638. Tubular piston rod 640 has a proximal end 642 that rests on the base floor of lower tube 634 and an opposite distal end 644 that slidably extends upwardly through upper tube 632 and cartridge 636. The main piston 102, control valve 100 and the cartridge stop plate 174 are mounted within the cavity 638 of the distal end 644 of the piston rod 640 as previously discussed in fig. 1-7.

Rebound channel 88 is also formed on piston rod 640 to extend between opposite ends of main piston 102 as disclosed with respect to damper 10. However, in contrast to rebound channel 88 of damper 10, adjustment pin 641 having a tapered leading end is disposed within piston rod 640 in the embodiment depicted in FIG. 34. That is, by selecting a rotating adjustment pin 641 outside of lower tube 634, pin 641 can be adjusted to selectively restrict the flow of hydraulic fluid through rebound channel 88. In part, the slower the flow of hydraulic fluid through rebound passages, the slower the rebound of piston rod 640.

A hollow sleeve 646 is threaded into the distal end of cartridge 636. In turn, an end plug 648 having a stem 650 projecting from it within chamber 638 adjacent to it is threaded into sleeve 646. A first piston 652 surrounds and is slidably disposed on stem 650. First piston 652 forms a sealing engagement with stem 650 and cartridge 636. In this manner, first piston 652 forms a barrier that divides chamber 638 into a relatively proximal chamber 654 and a relatively distal chamber 656. Proximal chamber 654 is filled with hydraulic fluid while distal chamber 656 is filled with a compressed gas, such as air.

A second piston 660 is mounted opposite end plug 648 to also enclose stem 650. Second piston 660 is also in sealing engagement with stem 650 and cartridge 636. By rotating end plug 648, second piston 660 is advanced into distal chamber 656, effectively reducing the size of distal chamber 656. This also increases the pressure within proximal lumen 654 and distal lumen 656 and the compression ratio within distal lumen 656.

The fill valve 662 is mounted to the end plug 648. A passageway 664 extends from fill valve 662 through end plug 648 to distal chamber 656. As such, fill valve 662 may be used to selectively adjust the pressure and volume of gas within distal chamber 656.

Finally, although not required, base valve piston 668 is rigidly disposed within proximal chamber 654 between first piston 652 and piston rod 640. Base valve piston 668 is sealed against cartridge 636 and is substantially identical in construction to main piston 102 except for being solid. In particular, base valve piston 668 has compression ports 118 and rebound ports 122 extending therethrough. Deformable shims 670 and 672 are installed on opposite sides of base valve piston 668 as discussed in other embodiments to control the flow of hydraulic fluid through compression ports 118 and rebound ports 122, respectively. Base valve piston 668 thus further controls the flow of hydraulic fluid and the delivery of pressure which in part controls the damping properties.

Fig. 35 shows front fork 630 with piston rod 640 advanced into cavity 638.

The use of cartridge 636 as described above with respect to front fork 630 is relatively easy to manufacture and assemble. The use of cartridge 636 also allows the damper of the present invention to be retrofitted into existing forks. Fig. 36 depicts a front fork 676. Front fork 676 is identical to front fork 630 except that cartridge 636 is removed. Fig. 37 shows front fork 676 with piston rod 640 advanced into chamber 638, while fig. 38 shows front fork 676 with piston rod 640 withdrawn from chamber 638.

It is to be understood that all of the various damping structures disclosed herein may be incorporated into a front fork. As described in further examples, fig. 39 and 40 depict the front fork 680 where the control valve 100 has moved from the master piston 102 to the base valve piston 668. This system is similar to the damper discussed with reference to fig. 15-18.

The damper of the present invention discussed above provides automatic adjustment of the damping properties based on operating conditions, thereby optimizing damping. Different embodiments provide different optional manual damping adjustments and/or remote damping adjustments. Such adjustability allows the damper to be used effectively in different settings and in a variety of different vehicles or other systems. The design of the damper also facilitates manufacturing and assembly.

The present invention may be embodied in various forms without departing from the spirit thereof. For example, a number of examples are disclosed herein having different features for controlling damping properties. However, it is understood that different features may be mixed and matched to form different other unique assemblies. Accordingly, the described embodiments are to be considered in all respects only as illustrative and not restrictive. Therefore, the scope of the invention is specifically defined by the claims and their equivalents.

Claims (49)

1. A suspension system comprising

At least one damper, the at least one damper comprising:

a housing defining a main cavity;

an obstruction disposed in the main chamber dividing the main chamber into first and second opposing chambers, the obstruction preventing transmission of fluid or gas between the first and second chambers but allowing transmission of a pressure differential between the first and second chambers

A piston rod having a first end slidably disposed in the first cavity of the housing and an opposite second end disposed outside the first cavity;

a main piston disposed on a first end of the piston rod within the first chamber of the housing to slidably engage the housing in generally sealing engagement, the main piston having a first side and an opposing second side with a compression port extending therebetween;

a hydraulic fluid disposed in the first chamber, the hydraulic fluid having a fluid pressure; and

a control valve assembly disposed in the first chamber, the control valve assembly defining a sealed valve chamber, the control valve assembly being movable between a first position in which the valve chamber is compressed to a first volume and a second position in which the valve chamber is expanded to a second volume, the second volume being greater than the first volume; and

means for remotely adjusting the fluid pressure of the hydraulic fluid in the first chamber of the at least one damper.

2. A suspension system as recited in claim 1, wherein the control valve assembly is configured such that the control valve assembly substantially blocks the compression port on the main piston when the control valve assembly is in the first position and the compression port is substantially unobstructed when the control valve assembly is in the second position.

3. A suspension system as recited in claim 1, wherein the control valve assembly is aligned in a compression port on the master piston such that when the master piston is advanced to the first chamber, the control valve assembly is at least partially moved to the second position, causing hydraulic fluid to pass through the compression port.

4. A suspension system as recited in claim 1, wherein the sealed valve chamber of the control valve contains a gas at a first pressure.

5. A suspension system as recited in claim 4, wherein the compressible gas is disposed within a second chamber, the gas within the second chamber being at a second pressure that is greater than the first pressure within the valve chamber of the control valve assembly.

6. A suspension system as set forth in claim 5 wherein said means for remotely adjusting the fluid pressure of the hydraulic fluid in the first chamber of said at least one damper includes:

means for providing a compressed gas;

a conduit extending from the means for providing compressed gas in fluid communication to a second chamber of at least one damper;

a regulator configured to automatically or alternatively regulate a pressure of the compressed gas within the second chamber.

7. A suspension system according to claim 6, wherein the means for providing compressed gas comprises a compressor or a compressed gas cartridge.

8. A suspension system as recited in claim 6, further comprising at least one sensor or variable switch in electrical communication with the regulator.

9. A suspension system as recited in claim 1, further comprising a spring disposed within the second chamber and biasing the obstruction.

10. A suspension system as set forth in claim 9 wherein said means for remotely adjusting the fluid pressure of the hydraulic fluid in the first chamber of said at least one damper includes:

means for compressing the spring within the second chamber; and

a central processing unit in electrical communication with the means for compressing the spring.

11. A suspension system as recited in claim 10, further comprising at least one sensor or variable switch in electrical communication with the central processing unit.

12. The suspension system of claim 1, wherein the obstruction comprises a floating piston.

13. A suspension system as recited in claim 1, wherein the obstruction includes an inflatable bladder disposed within the main chamber of the housing, the bladder defining a second chamber.

14. A suspension system as recited in claim 1, wherein the barrier comprises a deformable diaphragm mounted to the housing within the main cavity.

15. The suspension system of claim 14, wherein the housing comprises:

an inner sidewall defining an interior cavity; and

an outer sidewall surrounding the inner sidewall, an outer cavity formed between the inner sidewall and the outer sidewall in fluid communication with the inner cavity, the inner cavity and the outer cavity combining to form a main cavity.

16. A suspension system as recited in claim 15, wherein the master piston and the control valve are disposed within the internal cavity.

17. A suspension system as recited in claim 15, wherein the barrier comprises an inflatable bladder disposed within an outer cavity of the housing.

18. The suspension system of claim 1, wherein the housing comprises:

a primary housing defining a primary cavity;

a secondary shell separate from the primary cavity, the secondary shell defining a secondary cavity, the combined primary and secondary shells forming a main cavity; and

a tubular stem fluidly communicating the primary and secondary lumens.

19. A suspension system as recited in claim 18, wherein the master piston and the control valve assembly are disposed within the primary chamber.

20. A suspension system as recited in claim 18, wherein the master piston is disposed within a primary chamber and the control valve assembly is disposed within a secondary chamber.

21. A suspension system as recited in claim 18, wherein the obstruction is disposed within a secondary cavity of the housing.

22. A suspension system as recited in claim 18, further comprising a gas valve mounted on the secondary housing.

23. A suspension system as recited in claim 1, further comprising means for selectively adjusting a size of the second chamber.

24. A suspension system as set forth in claim 23 wherein the means for selectively adjusting the size of the second chamber includes an adjustable piston defining a portion of the second chamber, the adjustable piston selectively movable into the second chamber effective to reduce the size of the second chamber.

25. A suspension system as recited in claim 1, wherein the control valve assembly includes a control valve slidably disposed on a valve guide, the sealed valve chamber being formed between the control valve and the valve guide.

26. A suspension system as recited in claim 25, wherein the control valve has a first surface and an opposing second surface, each having a surface area, the aspect ratio of the surface of the first surface to the surface area of the second surface being in the range of about 0.2 to about 0.6.

27. A suspension system as recited in claim 1, wherein at least a portion of the control valve assembly is secured to or formed integrally with the primary piston.

28. The suspension system of claim 1, further comprising:

a rebound port extending between a first side and an opposite second side of the master piston; and

means for causing fluid to flow through the rebound ports from the first side to the second side of the master piston while preventing fluid from flowing from the second side to the first side of the master piston.

29. A suspension system as recited in claim 28, wherein the means for causing fluid to flow through the rebound ports comprises a deformable shim mounted to the second side of the master piston to cover the rebound ports thereon.

30. A suspension system as set forth in claim 1 further comprising an auxiliary piston disposed within the first chamber between the piston rod and the obstruction, the auxiliary piston having a first side and an opposite second side with the compression port extending therebetween.

31. A suspension system according to claim 30, wherein the auxiliary piston is rigidly connected to the housing.

32. A suspension system as recited in claim 30, wherein the control valve assembly is mounted to or adjacent the auxiliary piston such that the control valve assembly substantially blocks the compression port on the auxiliary piston when the control valve is in the first position and the compression port is substantially unobstructed when the control valve is in the second position.

33. A suspension system as recited in claim 30, further comprising:

a rebound port extending between a first side and an opposite second side of the auxiliary piston; and

means for causing fluid to flow through the rebound port from the second side to the first side of the auxiliary piston while preventing fluid from flowing from the first side to the second side of the auxiliary piston.

34. A suspension system as recited in claim 1, further comprising a rebound channel extending through the piston rod between a first opening formed in the piston rod on one side of the main piston and a second opening formed in the piston rod on an opposite side of the main piston.

35. A suspension system as recited in claim 34, further comprising a flow adjustment pin movably disposed within at least a portion of the rebound channel.

36. A suspension system as recited in claim 32, further comprising means for allowing fluid to flow through the rebound channel from the first opening to the second opening while preventing fluid from flowing from the second opening to the first opening.

37. A suspension system according to claim 1, wherein the piston rod comprises a rod body having a bolt attached thereto, the bolt extending through the main piston.

38. The suspension system of claim 1, wherein the main piston and valve guide assembly each encircle a piston rod.

39. The suspension system of claim 1, further comprising a brake plate mounted on the piston rod, the control valve assembly biasing the brake plate when the control valve assembly is in the second position.

40. A suspension system as set forth in claim 39 wherein said brake plate includes a first side and an opposing second side with an opening extending between the first side and the opposing second side.

41. A suspension system as set forth in claim 1 wherein said at least one damper comprises a portion of a shock absorber.

42. A suspension system as set forth in claim 1 wherein said at least one damper comprises a portion of a front fork.

43. The suspension system of claim 1, further comprising

A plurality of dampers; and

apparatus for automatically adjusting a fluid pressure of a hydraulic fluid within a first chamber of the at least one damper based on an automatic sensor signal or a manual input signal, the apparatus comprising:

means for delivering compressed gas to the second chamber of each of the plurality of dampers;

a central processing unit configured to independently control a gas pressure in the second chamber to each of the plurality of dampers.

44. A method of controlling a vehicle suspension, comprising:

providing a vehicle having a suspension system including at least one pressure-regulated damper; and

gas is automatically or alternatively delivered to or withdrawn from the at least one damper during vehicle operation to automatically or alternatively control suspension performance characteristics of the at least one damper.

45. The method of claim 44, wherein the suspension system includes a first pressure-regulated damper and a second pressure-regulated damper, the method further comprising controlling the delivery of gas to or extraction of gas from the first and second dampers, respectively, during operation of the vehicle.

46. The method of claim 44, wherein the transfer of gas to or extraction of gas from the at least one damper is performed during movement of the vehicle.

47. A method of controlling a vehicle suspension, comprising:

providing a vehicle having a suspension system including at least one damper, the damper comprising: a housing defining a cavity; a hydraulic fluid disposed in the cavity, the hydraulic fluid having a fluid pressure; a control valve assembly disposed in the chamber, the control valve assembly defining a sealed valve chamber, the control valve assembly being movable between a first position in which the valve chamber is compressed to a first volume and a second position in which the valve chamber is expanded to a second volume, the second volume being greater than the first volume; the control valve collapses to a first position due to fluid pressure exerted by the hydraulic fluid, an

Automatically or alternatively delivering gas to or withdrawing gas from the at least one damper during operation of the vehicle to automatically or alternatively control suspension performance characteristics of the at least one damper, the automatic or alternative change in fluid pressure being based on an automatic sensor signal or a manual input signal.

48. The method of claim 47, wherein the suspension system includes first and second dampers, the method further comprising controlling fluid pressure changes of the hydraulic fluid in the first and second dampers during operation of the vehicle, respectively.

49. The method of claim 47, wherein the automatic or optional change in fluid pressure of the hydraulic fluid in the at least one damper is made during movement of the vehicle.