U.S. patent application number 11/958149 was filed with the patent office on 2008-05-08 for hydraulic dampers with pressure regulated control valve.
This patent application is currently assigned to Turner Technology Group. Invention is credited to Roy A. Turner.
Application Number | 20080106012 11/958149 |
Document ID | / |
Family ID | 29712021 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080106012 |
Kind Code |
A1 |
Turner; Roy A. |
May 8, 2008 |
HYDRAULIC DAMPERS WITH PRESSURE REGULATED CONTROL VALVE
Abstract
A suspension damper includes a housing bounding a main chamber.
A hydraulic fluid is disposed within the main chamber. A piston rod
is selectively movable between an advanced position wherein a
portion of the piston rod is advanced into the main chamber and a
retracted position wherein the portion of the piston rod is
retracted from the main chamber, wherein as the piston rod is moved
a fluid pressure of the hydraulic fluid within the main chamber
progressively increases and a portion of the hydraulic fluid passes
through a passage within the housing. A control valve is at least
partially disposed within the main chamber, the control valve being
moved by the fluid pressure of the hydraulic fluid so as to
progressively restrict the flow of the hydraulic fluid through the
passage as the fluid pressure of the hydraulic fluid within the
main chamber progressively increases.
Inventors: |
Turner; Roy A.;
(Victorville, CA) |
Correspondence
Address: |
WORKMAN NYDEGGER
60 EAST SOUTH TEMPLE
1000 EAGLE GATE TOWER
SALT LAKE CITY
UT
84111
US
|
Assignee: |
Turner Technology Group
Victorville
CA
|
Family ID: |
29712021 |
Appl. No.: |
11/958149 |
Filed: |
December 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11228284 |
Sep 15, 2005 |
7308976 |
|
|
11958149 |
Dec 17, 2007 |
|
|
|
10449722 |
May 29, 2003 |
6978872 |
|
|
11228284 |
Sep 15, 2005 |
|
|
|
60384369 |
May 29, 2002 |
|
|
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Current U.S.
Class: |
267/64.15 |
Current CPC
Class: |
F16F 9/066 20130101;
F16F 9/5126 20130101; B60G 2202/154 20130101; F16F 9/512 20130101;
B60G 17/0424 20130101; F16F 9/46 20130101; B60G 2400/5182 20130101;
B60G 17/08 20130101; B60G 2500/10 20130101; F16F 9/064
20130101 |
Class at
Publication: |
267/064.15 |
International
Class: |
F16F 9/50 20060101
F16F009/50 |
Claims
1. A suspension damper comprising: a housing bounding a main
chamber; hydraulic fluid disposed within the main chamber; a piston
rod selectively movable between an advanced position wherein a
portion of the piston rod is advanced into the main chamber and a
retracted position wherein the portion of the piston rod is
retracted from the main chamber, wherein as the piston rod is moved
from the retracted position to the advanced position a fluid
pressure of the hydraulic fluid within the main chamber
progressively increases and a portion of the hydraulic fluid passes
through a passage within the housing; and a control valve at least
partially disposed within the main chamber, the control valve being
moved by the fluid pressure of the hydraulic fluid so as to
progressively restrict the flow of the hydraulic fluid through the
passage as the fluid pressure of the hydraulic fluid within the
main chamber progressively increases, the control valve being
mechanically separated from the piston rod.
2. The suspension damper as recited in claim 1, further comprising
a stationary piston rigidly secured to or integrally formed with
the housing, the stationary piston at least partially bounding the
passage through which the hydraulic fluid flows.
3. The suspension damper as recited in claim 1, further comprising
a resilient force pushing against the control valve in opposition
to the fluid pressure of the hydraulic fluid acting against the
control valve.
4. The suspension damper as recited in claim 1, further comprising
a spring biased against the control valve so as to produce a
resilient force acting against the control valve in opposition to
the fluid pressure acting against the control valve.
5. The suspension damper as recited in claim 1, further comprising
a compressed gas pushing against the control valve so as to produce
a resilient force acting against the control valve in opposition to
the fluid pressure acting against the control valve.
6. The suspension damper as recited in claim 1, wherein the control
valve is mechanically separated from the piston rod so that
movement of the piston rod does not directly move the control valve
but rather movement of the piston rod moves the control valve as a
result of changing the fluid pressure of the hydraulic fluid.
7. The suspension damper as recited in claim 1, wherein the control
valve is longitudinally spaced apart from the piston rod so that
the control valve does not encircle the piston rod.
8. The suspension damper as recited in claim 1, further comprising
a valve guide disposed adjacent to the control valve so that a
valve compartment is at least partially formed between the control
valve and the valve guide, the valve compartment being sealed from
the hydraulic fluid, a gas being disposed within the valve
compartment.
9. The suspension damper as recited in claim 1, further comprising
a barrier disposed within the main chamber that divides the main
chamber into a relative first chamber and a relative second
chamber, the barrier preventing the transfer of fluids or gasses
between the first chamber and the second chamber but enabling the
transfer of pressure between the first chamber and the second
chamber, a portion of the piston rod being disposed within the
first chamber.
10. The suspension damper as recited in claim 9, wherein the
barrier comprises a floating piston.
11. The suspension damper as recited in claim 9, wherein the
barrier comprises a bladder.
12. The suspension damper as recited in claim 9, further comprising
a gas valve mounted on the housing for selectively putting a gas
into or withdrawing a gas from the second chamber.
13. The suspension damper as recited in claim 9, further comprising
means for selectively adjusting the size of the second chamber.
14. The suspension damper as recited in claim 1, wherein the
housing comprises: a primary housing bounding a primary chamber; a
secondary housing spaced apart from the primary housing, the
secondary housing bounding a secondary chamber; and a fluid pathway
fluid coupling the primary chamber to the secondary chamber.
15. The suspension damper as recited in claim 14, wherein the
piston rod is partially disposed within the primary chamber and the
control valve is at least partially disposed within the fluid
pathway or the secondary chamber.
16. A suspension damper comprising: a housing comprising: a primary
housing bounding a primary chamber; a secondary housing bounding a
secondary chamber, the secondary housing being spaced apart from
the primary housing; and a fluid pathway extending between the
primary chamber and the secondary chamber; hydraulic fluid disposed
within at least a portion of the primary chamber, the secondary
chamber, and the fluid pathway; a piston rod coupled to the primary
housing and selectively movable between an advanced position
wherein a portion of the piston rod is advanced into the primary
chamber and a retracted position wherein the portion of the piston
rod is retracted from the primary chamber, wherein as the piston
rod is moved from the retracted position to the advanced position a
fluid pressure of the hydraulic fluid within the housing
progressively increases and a portion of the hydraulic fluid passes
through a passage within the housing; and a control valve at least
partially disposed within the secondary chamber or the fluid
pathway, the control valve being moved by the fluid pressure of the
hydraulic fluid so as to progressively restrict the flow of the
hydraulic fluid through the passage as the fluid pressure of the
hydraulic fluid within the housing progressively increases.
17. The suspension damper as recited in claim 16, wherein the
housing comprises a piggy back housing having a substantially
U-shaped configuration, a stem extending from the primary housing
to the secondary housing and bounding the fluid path.
18. The suspension damper as recited in claim 16, wherein the
primary housing has a central longitudinal axis and the secondary
housing has a central longitudinal axis that is offset from the
central longitudinal axis of the primary housing.
19. The suspension damper as recited in claim 16, further
comprising a stationary piston rigidly secured to or integrally
formed with the housing, the stationary piston at least partially
bounding the passage through which the hydraulic fluid flows.
20. The suspension damper as recited in claim 16, further
comprising a spring resiliently biased against the control valve in
opposition to the fluid pressure of the hydraulic fluid acting
against the control valve.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 11/228,284, filed Sep. 15, 2005, which is a
continuation of patent application Ser. No. 10/449,722, filed May
29, 2003, which claims the benefit to U.S. Provisional Application
Ser. No. 60/384,369, filed on May 29, 2002, which are incorporated
herein by specific reference.
BACKGROUND OF THE INVENTION
[0002] 1. The Field of the Invention
[0003] The present invention relates to hydraulic dampers which can
be used independently or as part of a shock absorber, front fork or
other suspension system.
[0004] 2. The Relevant Technology
[0005] Dampers are used in conventional shock absorbers, front
forks, and other suspension systems to dampen or absorb an impact
or force applied to the suspension system. For example, a
conventional damper includes a tubular housing bounding a sealed
chamber. An incompressible hydraulic fluid is disposed within the
chamber of the housing. One end of a piston rod having a piston
mounted thereon is also disposed within the chamber. Orifices
extend through the piston so that the piston can slide within the
chamber of the housing as the hydraulic fluid passes through the
orifices.
[0006] When a compressive force is applied to the damper, such as
when an automobile having shock absorbers hits a bump, the force
seeks to drive the piston rod into the chamber of the housing. The
damper partially absorbs this force by using the force to compress
the hydraulic fluid through orifices. When a rebound force is
applied to the damper, such as through the application of a spring,
the damper again regulates the rebound force by requiring the
hydraulic fluid to pass back through the orifices in the piston in
order for the piston rod to return to its original position.
[0007] Although conventional dampers impart some degree of damping
to suspension systems, conventional dampers have significant
shortcomings. For example, the damping properties of conventional
dampers are directly related to the constant restriction of the
hydraulic fluid flow through the orifices extending through the
piston. As this variable does not change along the stroke of the
piston rod, the damping properties are substantially constant
independent of the force applied or the position of the piston rod.
As a result, minimum damping performance is achieved. That is, what
is needed in the art are dampers for suspension systems that can
automatically adjust the damping characteristics throughout the
range of piston movement to more efficiently dampen based on
changing operating and road conditions.
[0008] Although attempts have been made to produce adjustable
dampers, such dampers have had minimal effectiveness, are difficult
and expensive to produce, and permit minimal selective adjustment
based on use and condition requirements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various embodiments of the present invention will now be
discussed with reference to the appended 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.
[0010] FIG. 1 is a cross sectional side view of one embodiment of a
damper;
[0011] FIG. 2 is an exploded perspective view the distal end of the
piston rod of the damper depicted in FIG. 1;
[0012] FIG. 3 is an enlarged cross sectional side view of the
components shown in FIG. 2 in an assembled state;
[0013] FIG. 4 is a cross sectional side view of the damper shown in
FIG. 1 with the control valve in an open state;
[0014] FIG. 5 is a cross sectional side view of the damper shown in
FIG. 4 with the piston rod being advanced into the housing;
[0015] FIG. 6 is a cross sectional side view of the damper shown in
FIG. 5 with the piston rod fully advanced into the housing;
[0016] FIG. 7 is a cross sectional side view of the damper shown in
FIG. 6 with the piston rod being retracted out of the housing;
[0017] FIG. 8 is a cross sectional side view of a spring biased
against the floating piston at the distal end of the damper shown
in FIG. 1;
[0018] FIG. 9 is a cross sectional side view of an inflated bladder
disposed at the distal end of the damper shown in FIG. 1;
[0019] FIG. 10 is a cross sectional side view of a flexible
diaphragm disposed at the distal end of the damper shown in FIG.
1;
[0020] FIG. 11 is a cross sectional side view of a boundary line
between a hydraulic fluid and a compressible gas disposed at the
distal end of the damper shown in FIG. 1;
[0021] FIG. 12 is a cross sectional side view of an alternative
embodiment of a damper having an adjusting piston;
[0022] FIG. 13 is a cross sectional side view of the damper shown
in FIG. 12 with the adjusting piston moved to a second
position;
[0023] FIG. 14 is a schematic representation of a remote pressure
regulated dampening system;
[0024] FIG. 15 is a cross sectional side view of an alternative
embodiment of a damper having a fixed control valve assembly;
[0025] FIG. 16 is a cross sectional side view of the damper shown
in FIG. 15 with the piston rod being advanced into the housing
thereof;
[0026] FIG. 17 is a cross sectional side view of the damper shown
in FIG. 16 with the piston rod being fully advanced into the
housing;
[0027] FIG. 18 is a cross sectional side view of the damper shown
in FIG. 17 with the piston rod being retracted out of the
housing;
[0028] FIG. 19 is a cross sectional side view of a twin tube
damper;
[0029] FIG. 20 is a cross sectional side view of the twin tube
damper shown in FIG. 19 with the piston rod being advanced into the
inner tube thereof;
[0030] FIG. 21 is a perspective view of a shock absorber;
[0031] FIG. 22 is an elevated front view of the shock absorber
shown in FIG. 21;
[0032] FIG. 23 is a an elevated side view of the shock absorber
shown in FIG. 21;
[0033] FIG. 24 is a cross sectional side view of the shock absorber
shown in FIG. 21;
[0034] FIG. 25 is a cross sectional view of the shock absorber
shown in FIG. 24 taken along section lines 25-25;
[0035] FIG. 26 is an enlarged cross sectional side view of the
second end of the stem of the shock absorber shown in FIG. 24;
[0036] FIG. 27 is an enlarged cross sectional side view of the gas
volume adjuster assembly of the shock absorber shown in FIG.
24;
[0037] FIG. 28 is a cross sectional side view of an alternative
embodiment of a damper having a base valve assembly;
[0038] FIG. 29 is an enlarged cross sectional side view of the base
valve assembly shown in FIG. 28;
[0039] FIG. 30 is a cross sectional side view of the damper shown
in FIG. 28 with the piston rod being advanced in the housing
thereof;
[0040] FIG. 31 is a cross sectional side view of the damper shown
in FIG. 30 with the piston rod being retracted from the
housing;
[0041] FIG. 32 is a cross sectional side view of an alternative
embodiment of the damper shown in FIG. 28 with the floating piston
being replaced by a flexible diaphragm;
[0042] FIG. 33 is a cross sectional side view of an alternative
embodiment of the damper shown in FIG. 28 with the base valve
assembly being replaced by an alternative base valve assembly;
[0043] FIG. 34 is an elevated cross sectional side view of a front
fork with a cartridge incorporating a damper of the present
invention;
[0044] FIG. 35 is an elevated cross sectional side view of the
front fork shown in FIG. 34 with the piston rod being advanced into
the upper tube thereof;
[0045] FIG. 36 is an elevated cross sectional side view of the
front fork shown in FIG. 34 with the cartridge removed,
[0046] FIG. 37 is an elevated cross sectional side view of the
front fork shown in FIG. 36 with the piston rod being advanced into
the upper tube thereof;
[0047] FIG. 38 is an elevated cross sectional side view of the
front fork shown in FIG. 36 with the piston rod being retracted
from the upper tube thereof;
[0048] FIG. 39 is an elevated cross sectional side view of a front
fork having a fixed base valve in the upper tube; and
[0049] FIG. 40 is an elevated cross sectional side view of the
front fork shown in FIG. 39 with the piston rod being retracted
from the upper tube thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] The present invention relates to hydraulic dampers which can
be used independently or as part of a shock absorber, front fork or
other suspension system. Such dampers can be used in association
with all types of vehicles or mechanical apparatus where it is
desired to control suspension movement and/or vibration. Examples
of vehicles on which the dampers can be used include bicycles,
motorcycles, automobiles, all terrain vehicles, snowmobiles,
airplanes, and the like.
[0051] Depicted in FIG. 1 is one embodiment of a damper 10
incorporating features of the present invention. Damper 10
comprises a housing 12 having an interior surface 14 bounding a
chamber 16. Housing 12 comprises a cylindrical sidewall 18 that
extends between a proximal end 20 and an opposing distal end 22. An
end wall 24 is formed at distal end 22 of sidewall 18. A bracket 30
having a hole 32 extending therethrough is formed on end wall 24
for selectively attaching damper 10 to a structure. In alternative
embodiments, bracket 30 can be replaced with any conventional
attachment structure.
[0052] A cap 26 is removably threaded or otherwise attached onto
proximal end 20 of sidewall 18. Cap 26 has a passageway 28
centrally extending therethrough so as to communicate with chamber
16. A piston rod 34 is slideably disposed within passageway 28 so
as to extend into and outside of chamber 16. Piston rod 34 has an
exterior surface 36 extending between a proximal end 37 (FIG. 2)
and an opposing distal end 38. An annular seal 40 extends between
cap 26 and piston rod 34 so as to effect a sealed connection that
enables piston rod 34 to freely slide relative to housing 12.
[0053] Piston rod 34 comprises a base rod 42 and a bolt 44. As
depicted in FIG. 2, base rod 42 comprises an exterior surface 45
extending between a proximal end 46 and an opposing distal end 48.
Distal end 48 terminates at a distal end face 50. A substantially
L-shaped channel 52 (see also FIG. 3) extends from distal end face
50 to exterior surface 45 at distal end 48.
[0054] Bolt 44 comprises a shaft 56 having a proximal end 58 and an
opposing distal end 60. Proximal end 58 of shaft 56 terminates at a
proximal end face 64. As depicted in FIGS. 2 and 3, distal end 60
of shaft 56 terminates at a distal end face 66. Encircling and
radially outwardly projecting from shaft 56 at distal end 60 is a
head 70. Head 70 also has a proximal end face 72 and an opposing
distal end face 74. Distal end face 74 of head 70 is spaced
proximal of distal end face 66 of shaft 56. A channel 78 extends
through shaft 56 from distal end face 66 to proximal end face 64. A
plurality of radially spaced apart ports 79 extend from channel 78
to distal end face 74 of head 70. Removably threaded into channel
78 at distal end face 66 of shaft 56 is a jet 80 having an opening
82 extending therethrough. For reasons as will be discussed below
in greater detail, jet 80 can be replaced with other jets having
different sized openings. Alternatively, jet 80 can be replaced
with a plug so that the only access to channel 78 at distal end 60
of shaft 56 is through ports 79.
[0055] One or more flexible metal spring shims 84 are mounted on
distal end face 74 of head 70 so as to encircle shaft 56 and cover
the openings to ports 79. Shims 84 are secured in place by a C-clip
86 mating with a groove on shaft 56 distal of shims 84. In an
alternative embodiment, C-clip 86 can be replaced with a washer.
Jet 80 can then be formed with an outwardly projecting flange at
the end thereof. As jet 80 is screwed into channel 78, the flange
biases the washer against the shims 84 so as to secure shims 84 in
place.
[0056] During assembly, proximal end 58 of bolt 44 is threaded into
distal end 48 of base rod 42 so that channels 52 and 78 are in
fluid communication. The combination of channels 52 and 78 are
herein referred to as rebound channel 88. In alternative
embodiments, it is appreciated that base rod 42 and bolt 44 can be
integrally formed as a single member. Furthermore, bolt 44 can be
replaced with a nut that threads onto the distal end of base rod
42.
[0057] Depicted in FIG. 2, mounted on distal end 38 of piston rod
34 is a main piston 102, a control valve assembly 100, and a stop
plate 174. Control valve assembly 100 comprises a valve guide 104
and a control valve 106. Main piston 102 has a substantially
circular disk shape configuration with a proximal face 108, an
opposing distal face 110, and a peripheral side 112 extending
therebetween. A groove 113 is formed on peripheral side 110 so as
to receive an annular seal 114 (FIG. 3). In the embodiment
depicted, seal 114 comprises a flexible o-ring 96 that outwardly
biases an annular band 98. Band 98 is typically comprised of
Teflon. Other conventional seal configurations can also be used. It
is noted that in several of the other drawings showing pistons, the
annular seal has been not been shown in the peripheral groove. This
was done so as to help clarify the drawings. It is appreciated that
in use, however, a seal is disposed within each peripheral
groove.
[0058] 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 at a substantially constant
radius from the center of main piston 102. Disposed on proximal
face 108 between each adjacent pressure port 118 is an elongated
shallow pocket 120. Each pocket extends along a radial axis aligned
with the center of main piston 102. Extending from distal face 110
of main 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 though main
piston 102.
[0059] In the assembled state depicted in FIG. 3, piston rod 34 is
passed though central opening 116 of main piston 102 so that main
piston 102 encircles and radially outwardly projects from piston
rod 34 proximal of head 70. Seal 114 is biased in sealed engagement
against interior surface 14 of sidewall 18 so as to enable main
piston 102 to freely slide within chamber 16 as piston rod 34 is
moved within chamber 16.
[0060] In one embodiment of the present invention means are
provided for enabling fluid flow through rebound port 122 from
proximal face 108 to distal face 110 while precluding fluid flow
from distal face 110 to proximal face 108. By way of example and
not by limitation, a plurality of stacked shims 124 encircle piston
rod 34 and bias against distal face 110 of main piston 102. Stacked
shims 124 cover the distal opening to rebound ports 122 but do not
cover the openings to compression ports 118. A washer 126 is
disposed between head 70 and stacked shims 124 so as to provide
space for the outer perimeter of stacked shims 124 to flex
distally. Fluid can thus travel in a distal direction through
rebound ports 122 by flexing shims 124, but is precluded from
traveling in a proximal direction through rebound ports 122 as a
result of shims 124. Shims 124 thus act as a type of one-way check
valve during compressive movement of piston rod 34 and pressure
sensitive valves during the rebound movement of piston rod 34. That
is, the greater the fluid pressure against shims 124 during the
rebound stroke, the farther shims 124 flex and the more rebound
ports 122 are opened.
[0061] In alternative embodiments of the means for enabling fluid
flow through rebound port 122, it is appreciated that shims 124 can
be replaced with any number of alternative one-way check valve
designs. For example, flexible shims 124 can be replaced with a
solid washer or hinged flaps that are biased against distal face
110 over rebound ports 122 by a spring. One such example is
discussed below with regard to FIG. 29. It is noted that there are
a number of different elements and alternative designs disclosed
herein which incorporate flexible shims as a one-way check valve.
It is appreciated that each such use of shims is intended to have a
corresponding means for enabling fluid flow in a select direction
and that such shims can be replaced with alternative one-way check
valve designs as discussed above.
[0062] Depicted in FIG. 2, valve guide 104 comprises an annular
base 130 having a proximal face 132 and an opposing distal face
134. Projecting from distal face 132 is an annular stem 136. Stem
136 has an outer diameter smaller than the outer diameter of base
130. A central opening 138 extends through both stem 136 and base
130. In the assembled state depicted in FIG. 3, piston rod 34 is
passed through central opening 138 so that distal face 134 of valve
guide 104 rests against proximal face 108 of main piston 102. Valve
guide 104 only partially covers pockets 120 so that fluid
communication is still made with rebound ports 122 though pockets
120. It is noted that valve guide 104 is locked in place by being
clamped between a shoulder 181 formed on piston rod 34 and main
piston 102. In alternative embodiments, it is appreciated that
valve guide 104 can be directly secured to or integrally formed
with main piston 102.
[0063] Depicted in FIGS. 2 and 3, control valve 106 has an annular
peripheral side 144 extending between an annular distal face 146
and an annular proximal face 148. Distal face 146 has a surface
area smaller 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 in a range between
about 0.3 to about 0.6 with about 0.3 to about 0.4 being more
preferred. In general, control valve 106 comprises an annular
collar 150 having an interior surface 152. An annular flange 154
radially inwardly projects from interior surface 152 of collar 150
at a proximal end thereof. Flange 154 has a proximal face 155 that
terminates at an interior surface 157. A central opening 156
extends through both collar 150 and flange 154.
[0064] In the assembled state, piston rod 34 is slideably received
within central opening 156 so that control valve 106 slideably
mates with valve guide 104. Specifically, in the position depicted
in FIG. 3, collar 150 of control valve 106 encircles base 130 of
valve guide 104. An annular groove 158 is formed on interior
surface 152 of collar 150 and receives an annular first seal 160.
First seal 160 biases against base 130 of valve guide 104 so as to
form a slideable sealed engagement between collar 150 and base
130.
[0065] Flange 154 of control valve 106 encircles stem 136 of valve
guide 104. An annular groove 162 is formed on interior surface 157
of flange 154 and receives an annular second seal 164. Second seal
164 biases against stem 136 of valve guide 104 so as to form a
slideable sealed engagement between flange 154 and stem 136. It is
noted that in several of the other drawings showing control valve
assembly 100, first seal 160 and second seal 164 are not shown in
their corresponding grooves. This was done so as to help clarify
the drawings. It is appreciated that in use, however, seals 160 and
164 are disposed within their corresponding grooves in each control
valve assembly 100.
[0066] An annular groove 166 is also formed on the interior surface
of control valve 106 between first seal 158 and second seal 164. In
part, groove 166 bounds a valve chamber 170 formed between control
valve 106 and valve guide 104 and which is sealed closed by first
seal 158 and second seal 164. Disposed within valve chamber 170 is
a compressible gas such as air. In one embodiment, as control valve
106 is received over valve guide 104, air is captured within valve
chamber 170 at a first pressure, i.e., atmospheric pressure. In
alternative embodiments, it is appreciated that a resiliently
compressible member such as a spring or compressible material can
also be disposed within valve chamber 170 so as to bias between
valve guide 104 and control valve 106.
[0067] As depicted in FIG. 2, annular stop plate 174 has a distal
side 176 and an opposing proximal side 178. A central opening 180
and a plurality of radially spaced apart ports 182 extend through
stop plate 174 between opposing sides 176 and 178. As depicted in
FIG. 3, distal end 48 of base rod 42 is passed through central
opening 180 such that stop plate 174 is captured between a shoulder
181 of base rod 42 and valve guide 104.
[0068] Stop plate 174 functions as a stop for control valve
assembly 100. Specifically, control valve assembly 100 operates at
various states between an open position and a closed position. In
the closed position depicted in FIG. 3, distal face 146 of control
valve 106 biases against proximal face 108 of main piston 102 so as
to cover the proximal openings to compression ports 118. However, a
portion of pockets 120 on main piston 102 are not covered by
control valve 106 or valve guide 104 so that open fluid
communication is provided to rebound ports 122 through pockets 120.
As discussed below in greater detail, it is also noted that when
control valve 106 is in the closed position, valve chamber 170 is
collapsed so as to have a first volume.
[0069] Depicted in FIG. 4, control valve assembly 100 is in the
fully open position. In this configuration, control valve 106 has
slid proximally relative to valve guide 104 so that proximal face
148 of control valve 106 is biased against stop plate 174, thereby
stopping further proximal movement of control valve 106. In this
open position, control valve 106 is spaced apart from main piston
102 so that fluid is free to travel through the compression ports
118 and through a flow channel 167 formed between control valve 106
and main piston 102. It is also noted that in the open position,
distal face 155 of flange 154 of control valve 106 is spaced apart
from proximal face 132 of base 130 of valve guide 104, thereby
expanding valve chamber 170 so as to have a second volume that is
lager 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 the natural tendency to
push control valve 106 into the open position under a force
corresponding to the relative pressure within valve chamber
170.
[0070] Returning to FIG. 1, slideably disposed within chamber 16
distal of piston rod 34 is a floating piston 184. Floating piston
184 has a peripheral side 186 that extends between a distal face
188 and an opposing proximal face 190. A seal 192 is disposed on
peripheral side 186. Seal 192 biases in sealed engagement against
interior surface 14 of sidewall 18 of housing 12 so as to enable
floating piston 184 to selectively slide within chamber 16 but
substantially precluding fluid or gas from passing through or
around floating piston 184.
[0071] Floating piston 184 divides chamber 16 into a distal
compartment 196 and a proximal compartment 198. Compartments 196
and 198 each change in relative size as floating piston 184 slides
within chamber 16. Disposed within distal compartment 196 is a
compressible gas, such as air, while disposed within proximal
compartment 198 is a hydraulic fluid. As used in the specification
and appended claims, the term "hydraulic fluid" is intended to
include all types of fluids that can be used to transfer hydraulic
pressures. Although hydraulic fluids are generally considered as
being substantially non-compressible, it is appreciated that
hydraulic fluids can be emulsified or have entrained gas, thereby
making them slightly compressible.
[0072] The gas within distal compartment 196 is disposed at a
second pressure that is greater than the first pressure of the gas
within valve chamber 170. Accordingly, in the static position shown
in FIG. 1 with piston rod 34 retracted out of chamber 16, control
valve 106 is in the closed position. That is, the pressure within
distal compartment 196 is transferred through floating piston 184
and the hydraulic fluid within proximal compartment 198 so to
collapse valve chamber 170 and move valve guide 106 into the closed
position.
[0073] In general, control valve 106 is closed because of the
opposing forces applied 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
control valve assembly 100 more effectively operates under the
applied pressures to move between the open and closed positions if
the surface area of distal side 134 of valve guide 104 is at least
50%, preferably at least 60% and more preferably at least 70% of
the surface area of proximal face 148 of control valve 106.
[0074] During operation, when a force is applied to proximal end 37
of piston rod 34 which is greater than the force which is
maintaining control valve assembly 100 in the closed position,
piston rod 34 with main piston 102 and control valve assembly 100
begin to move distally within chamber 16. Specifically, as depicted
in FIG. 4, as piston rod 34 moves distally within chamber 16, the
hydraulic fluid within proximal compartment 198 travels through
compression ports 118 and pushes against distal face 146 of control
valve 106, thereby causing control valve 106 to at least partially
slide into the open position.
[0075] Control valve assembly 100 meters the flow of hydraulic
fluid through compression ports 118 during the advancement of main
piston 102. The extent to which control valve 106 slides distally
in part depends on the rate 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., sharp hi-speed bump force, control valve
assembly 100 is quickly moved to the fully open position as a
result of the high pressures that are produced in proximal
compartment 198 and applied to distal face 146 of control valve
106. The hydraulic fluid can thus freely travel through compression
ports 118 and around control valve 106, thereby allowing piston rod
34 to rapidly and easily advance within chamber 16. As such, the
impact of the initial force on piston rod 34 is quickly absorbed by
movement of piston rod 34. In contrast, if a gradual small force is
applied to piston rod 34, control valve 106 is only partially moved
to the open position so that flow passageway 167 remains partially
constricted. This constriction of flow passageway 167 decreases the
flow of hydraulic fluid through compression ports 118 and thus
slows of movement of main piston 102 within chamber 16.
[0076] As depicted in FIG. 5, as more of piston rod 34 enters
proximal compartment 198, piston rod 34 displaces a corresponding
volume of the hydraulic fluid therein. Because the hydraulic fluid
does not significantly compress, the hydraulic fluid causes
floating piston 184 to slide distally and compress the gas with
distal compartment 196. As the gas pressure increases within distal
compartment 196, the fluid pressure within proximal compartment 198
increases and the fluid pressure begins to collapse valve chamber
170, thereby moving control valve 106 into the closed position. As
control valve 106 moves into the closed position, flow channel 167
constricts making it more difficult for the hydraulic fluid to pass
therethrough. Accordingly, the farther piston rod 34 advances into
chamber 16, the greater the resistance force that is applied
against piston rod 34.
[0077] As depicted in FIG. 6, piston rod 34 is stopped from further
advancement into chamber 16 when control valve assembly 100 returns
to the closed position. This occurs when a sufficient length of
piston rod 34 has entered proximal compartment 198 such that the
hydraulic fluid pressure tending to move control valve assembly 100
into the closed position, thereby precluding fluid travel through
compression ports 118, is greater than the external force applied
to piston rod 34 which tends to cause the hydraulic fluid to move
the control valve into the open position.
[0078] As will be discussed below, in alternative embodiments the
initial pressure within and the volume of distal compartment 196
can be selectively adjusted. The initial pressure and volume of
distal compartment 196 has a number of effects on the damping. For
example, by increasing the initial pressure within distal
compartment 196, increased force is initially applied by the
hydraulic fluid to maintain control valve assembly 100 in the
closed position. As such, greater force to piston rod 34 is
required to initially move control valve assembly 100 into the open
position.
[0079] Furthermore, having a higher initial pressure within distal
compartment 196 causes control valve assembly 100 to close earlier
as piston rod 34 is advanced into proximal compartment 198. That
is, the gas pressure within distal compartment 196, and thus also
the hydraulic fluid pressure within proximal compartment 198,
increases exponentially as the volume of distal compartment 196 is
compressed. The increase in pressure is based on the compression
ratio of distal compartment 196, i.e., the starting volume of
distal compartment 196 versus the final volume of distal
compartment 196 when piston rod 34 is advanced into chamber 16. For
example, if the starting volume of distal compartment 196 is 100 cc
and the final volume is 25 cc, the compression ratio is 4:1. As a
result, the gas pressure and thus also the hydraulic fluid pressure
in the final volume is four times the gas pressure in the starting
volume. The pressure continues to increase exponentially as the
volume of distal compartment 196 decreases by compression.
[0080] It is also appreciated that the starting volume of distal
compartment 196 can be adjusted separately from the initial
pressure therein so as to separately effect the damping properties.
For example, in a first embodiment the initial volume of distal
compartment 196 can be 100 cc while in a second embodiment the
initial volume can be 75 cc. Assuming the starting gas pressure in
each embodiment is the same, the same initial force is applied to
control valve 100 as discussed above. However, for the same
advancement of piston rod 34 in each of the embodiments, the
compression ratio for the second embodiment is greater because the
initial volume is smaller. As such, the rate of pressure increase
and resulting damping force is greater for the second embodiment
relative to the first embodiment.
[0081] In view of the foregoing, during a compressive movement of
main piston 102, a virtually infinite combination of pressures can
be applied to control valve assembly 100 as a result of:
displacement of piston rod 34 and the resulting pressure changes
within chamber 16; varying bump loads and resulting pressures that
are generated within the chambers on each side of main piston 102;
and the resulting pressures that are variably generated upon distal
face 134 of valve guide 104 and proximal face 148 of control valve
106 through out the stroke of piston rod 34.
[0082] The resulting metering of hydraulic fluid flow through
pressure ports 118 on main piston 102 by control valve assembly 110
during a compressive movement of main piston 102 thus produces
damping effects which are: position sensitive as a result of the
position of piston rod 34 within proximal compartment 198; variable
position and load sensitive depending on the position of main
piston 102, speed/force of the bump input, and pressure within the
distal compartment 196; and position and/or load adjustable, by
varying the volume and force of the pressure within distal
compartment 196.
[0083] Depicted in FIG. 7, during rebound when piston rod 34 is
being drawn out of chamber 16, the pressure applied by the
hydraulic fluid keeps control valve assembly 100 closed, thereby
preventing the hydraulic fluid that is now proximal of control
valve 106 from passing through compression ports 118. Rather, the
hydraulic fluid flows through one of possibly three rebound paths.
In a first path, the hydraulic fluid enters rebound channel 88
proximal of stop plate 174, travels centrally through piston rod 34
along rebound channel 88, and then travels out through ports 79 by
distally flexing shims 84. In a second rebound path, rather then
traveling out through ports 79, the hydraulic fluid within rebound
channel 88 travels out through jet 80. In the third rebound path,
the hydraulic fluid travels around the exterior of control valve
106 and enters pockets 120 of main piston 102. The hydraulic fluid
then travels out through rebound ports 122 by distally flexing
shims 124.
[0084] By adjusting the stiffness and/or number of shims 84, 124
and the size of opening 82 in jet 80, the hydraulic fluid can
simultaneously flow through one, two, or all three of the rebound
paths. For example, by having shims 124 stiffer than shims 84, the
hydraulic fluid may flow only through jet 80 at low rebound forces.
At a higher rebound force, the hydraulic fluid may flow through
both the first and second rebound path or through all three rebound
paths.
[0085] The rebound force, typically produced by an opposing spring,
is generally greatest when piston rod 34 is fully inserted into
chamber 16 (FIG. 6) and initially begins to move in the rebound
direction. As such, all of the rebound paths may initially be used
as piston rod 34 begins to retract. However, as piston rod 34
continues to move in the rebound direction, one or more of the
rebound paths may close off, thereby slowing the rebound as piston
rod 34 approaches the fully retracted position. As will be
discussed below with regard to alternative embodiments, rebound
channel 88 can also be selectively restricted or closed so as to
enable manual control of the hydraulic fluid therethrough based on
operating parameters.
[0086] As discussed above, the compressible gas is sealed within
distal compartment 196 so as to enable piston rod 34 to travel into
chamber 16 through the compression of the gas and to at least
partially control the operation of control valve assembly 100 by
producing variable pressure thereon. It is appreciated, however,
that there are a number of alternative ways in which these same
functions can be achieved.
[0087] For example, depicted in FIG. 8 a resiliently compressible
member 246 is disposed within distal compartment 196. Member 246
extends between floating piston 184 and distal end wall 24.
Although member 246 is shown as being a coiled spring, in
alternative embodiments member 246 can comprise other forms of
mechanical springs or blocks of resiliently compressible material
such as rubber or polymeric foam. As the hydraulic pressure
increases in proximal chamber 198, floating piston 184 slides
distally resiliently compressing member 246. In this regard,
compressed member 246 functions similar to the compressed gas.
[0088] It is appreciated that member 246 can be used in addition to
or independent of filling distal compartment 196 with a gas at
elevated pressure. Where member 246 is independently used to
provide the compressive resistance, distal compartment 196 need not
be sealed closed within housing 12. For example an opening depicted
by dashed lines 248 can be formed through distal end wall 24.
Opening 248 facilitates proper placement of floating piston 184. In
other embodiments, it is appreciated that member 246 need not be
disposed within chamber 16 but can be disposed outside of chamber
16. For example, a rod can extend from floating piston 184 through
distal end wall 24 where it connects with member 246 outside of
housing 12.
[0089] In another alternative embodiment depicted in FIG. 9, a
flexible bladder 250 is disposed within the distal end of chamber
16. Bladder 250 communicates with the exterior of housing 12
through a fill valve 252 such as Schrader charge valve. Fill valve
252 enables bladder 250 to be selectively inflated with gas to a
desired pressure. It is noted that bladder 250 can be used in
association with or independent of floating piston 184. That is,
floating piston 184 can be eliminated so that the hydraulic fluid
directly bears against inflated bladder 250 so as to compress
bladder 250. In this embodiment, bladder 250 bounds distal
compartment 196. Bladder 250 can also be filled with resiliently
compressible material such as rubber or polymeric foam.
[0090] Depicted in FIG. 10, floating piston 184 is replaced with a
flexible diaphragm 254. Diaphragm 254 is mounted to interior
surface 14 of sidewall 18 of housing 12 so as to divide chamber 16
into distal compartment 196 and proximal compartment 198. A fill
valve 256 is formed on sidewall 18 and enables distal compartment
196 to be filled with a compressible gas to a desired pressure.
Again, as piston rod 34 is advanced into chamber 16, the hydraulic
fluid presses against diaphragm 254 causing it to flex distally,
thereby compressing the gas within distal compartment 196.
[0091] It is appreciated that in other embodiments no mechanical
barriers are required. For example, depicted in FIG. 11 chamber 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 gas 260. In some uses,
however, this embodiment is less desirable as the gas and hydraulic
fluid can mix or emulsify within chamber 16 and diminish operating
properties.
[0092] Set forth below are a number of alternative embodiments of
dampers wherein like elements are identified by like reference
characters. In one embodiment of the present invention means are
provided for selectively adjusting the size of distal compartment
196. By way of example, depicted 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 distal
of floating piston 184. Adjusting piston 212 includes a peripheral
side 214 having a seal 216 formed thereat. Seal 216 is biased in
sealed engagement against interior surface 14 of sidewall 18 of
housing 12 so as to enable adjusting piston 212 to selectively
slide within chamber 16 without allowing fluid to pass through or
around.
[0093] Centrally mounted on adjusting piston 212 is a sleeve 218.
Sleeve 218 has a threaded bore 220 which opens distally. In
alternative embodiments, it is appreciated that threaded bore 220
can be formed directly on the distal face of adjusting piston
212.
[0094] Mounted on housing 12 is a knob 222. Knob 222 has a first
end with an enlarged head 224 formed thereat. Head 224 is at least
partially exposed outside of housing 12 so as to enable selective,
manual rotation of head 224. A threaded shaft 226 is formed at an
opposing second end of knob 222. Threaded shaft 226 is threadedly
engaged with bore 220 on piston 212. Accordingly, as depicted in
FIGS. 12 and 13, by selectively rotating head 224 of knob 222,
adjusting piston 212 is selectively advanced and retracted within
the distal end of chamber 16.
[0095] In this embodiment, distal compartment 196 is bounded
between adjusting piston 212 and floating piston 184. By manually
advancing adjusting piston 212 toward floating piston 184, distal
compartment 196 becomes smaller. By making distal compartment 196
smaller, the gas pressure can be increased therein and the rate at
which the pressure increases within proximal compartment 198 as
floating piston 184 moves distally increases. Alternative
embodiments of the means for selectively adjusting the size of
distal compartment are discussed below.
[0096] Also mounted on housing 12 so as to communicate with distal
compartment 196 is a fill valve 228. As previously discussed, fill
valve 228 can comprise a conventional air valve such as used on car
and bike tires. Fill valve 228 can thus be used to selectively
increase or decreases the gas pressure within distal compartment
196. For example, air can be added to or removed from distal
compartment 196 so as to selectively increase or decrease the gas
pressure therein. Again, as previously discussed, the gas pressure
affects the operation of control valve 100 and thus the movement of
piston rod 34. Accordingly, adjusting piston 212 and fill valve 228
enable an end user to selectively adjust dampening properties of
damper 210 based on current or expected operating parameters.
[0097] In one embodiment of the present invention, means are
provided for remotely adjusting the fluid pressure of the hydraulic
fluid within proximal compartment 198 of damper 10. By way of
example and not by limitation, depicted in FIG. 14 is one
embodiment of a pressure regulated damping system 232. Dampening
system 232 includes means for providing a compressed gas. Examples
of such means includes air source 234 which can comprise a
compressor or tank holding compressed gas. Damping system 232
further comprises a pressure regulator 235 and one or more of
dampers 10. A port 238 is provided in gas communication with distal
compartment 196 of each damper 10. Supply lines 240 provide gas
communication between air source 234 and pressure regulator 235. In
turn, supply lines 242, such as tubes or any other form of conduit,
provide gas communication between pressure regulator 235 and distal
compartment 196 of each damper 10 by way of port 238.
[0098] Regulator 235 can be manually, electronically, and/or
computer controlled so as to selectively or automatically adjust
the pressure independently within distal compartment 196 of each
damper 10 as the operating environment for dampers 10 change. By
increasing the pressure in distal compartment 196, the pressure
differential is transferred through floating piston 184 so as to
increase the fluid pressure of the hydraulic fluid within proximal
compartment 198. In turn, increasing the hydraulic fluid pressure
adjusts the operation of control valve 100 and thus the damping
properties of damper 10. It is appreciated that regulator 235 can
come in a variety of different configurations and can be comprised
of multiple discrete components.
[0099] As one example of use, one or more dampers 10 can be
incorporated into the shock absorbers of an automobile or any other
type of vehicle. As road and operating conditions change, for
example, straight versus curvy, on-road versus off-road,
accelerating versus breaking, the rapid remote adjustment of the
hydraulic fluid pressure can be used to provide optimum suspension
performance. It is appreciated that optimum performance will often
be obtain by simultaneously separately adjusting the hydraulic
fluid pressure in each of dampers 10 on a vehicle.
[0100] To facilitate automatic damping adjustment, one or more
sensors 243, such as a gyroscopic sensor or other movement
sensitive sensors, can be mounted on the vehicle and in electrical
communication with a central processing unit (CPU) 244. CPU 244 may
be separate from or form a portion of regulator 235. Based on
inputs from the one or more sensors 243, CPU 244 can control
regulator 235 so as to accordingly adjust the gas pressure and
resulting hydraulic fluid pressure in one or more of dampers 10 on
the vehicle.
[0101] As an alternative to automatic adjustment, a manual input
mechanism 245, such as a switch or control panel, can be
electrically coupled with CPU 244. Inputs provided to manual input
mechanism 245 can be used to set the hydraulic fluid pressure in
each of dampers 10 to a predefined valve.
[0102] The use of gas pressure is only one example of the means for
remotely adjusting the fluid pressure of the hydraulic fluid within
proximal compartment 198 of damper 10. As an alternative
embodiment, spring 246 of FIG. 8 can be disposed between floating
piston 184 and adjusting piston 212 of FIG. 12. In turn, a motor or
other form of gear mechanism is attached knob 222 in FIG. 12.
Central processing unit 244 is electrically coupled with the motor
such that based on sensor or manual input signals the motor adjusts
the compression on spring 246 so as to remotely adjust the
hydraulic fluid pressure in dampers 10.
[0103] It is appreciated that there are a variety of different
systems that can be used to remotely adjust the fluid pressure of
the hydraulic fluid within dampers 10 by selectively adjusting the
pressure applied to floating piston 184 or one of the alternatives
discussed thereto.
[0104] In view of the foregoing the suspension of a vehicle can be
controlled by providing a vehicle having a suspension system
including at least one pressure regulated damper; and automatically
or selectively delivering a gas to or withdrawing a gas from the at
least one damper during operation of the vehicle so as to
automatically or selectively control suspension performance
properties of the at least one damper. Such suspension control can
be performed during movement of the vehicle.
[0105] Likewise, suspension control can be obtained by
automatically or selectively altering the fluid pressure of the
hydraulic fluid within the at least one damper during operation of
the vehicle so as to automatically or selectively control
suspension performance properties of the at least one damper, the
automatic or selective altering of the fluid pressure being based
on automatic sensor signals or manual input signals.
[0106] Depicted in FIG. 15 is another alternative embodiment of a
damper 270 incorporating features of the present invention. Damper
270 includes housing 12 bounding chamber 16. Chamber 16 is divided
by floating piston 184 into distal compartment 196 and proximal
compartment 198 which contain a compressed gas and hydraulic fluid,
respectively. Again, floating piston 184 can be replaced with any
of the alternatives as previously discussed.
[0107] A piston rod 272 slideably extends into the proximal end of
housing 12. Piston rod 272 includes a base rod 278 and a bolt 280.
Bolt 280 is screwed onto the distal end face of base rod 278 so as
to secure main piston 102 therebetween. Seal 114 is mounted on the
peripheral side of main piston 102 and forms a slideable sealed
biased engagement against interior surface 14 of sidewall 18.
[0108] Secured between an enlarged head 281 of bolt 280 and distal
face 110 of piston 102 is a first shim 282. First shim 282 is
biased against distal face 110 of piston 102 so as to cover the
distal openings to rebound ports 122. A second shim 284 is disposed
between the distal end of base rod 278 and proximal face 108 of
piston 102. Second shim 284 is biased against proximal face 108 of
piston 274 so as to cover the proximal openings of compression
ports 118. However, second shim 284 only covers a portion of
pockets 120 leading to rebound ports 122. As previously discussed
with regard to shims 124 in FIG. 3, shims 282 and 284 function as
one-way check valves which control the direction of flow through
rebound ports 122 and compression ports 118, respectively. The
alternatives as previously discussed with regard to shims 124 are
also applicable to shims 282, 284, and the flexible shims disclosed
in other embodiments of the present invention.
[0109] In contrast to damper 10 wherein control valve assembly 100
is mounted to the moveable piston rod, in the present embodiment
control valve assembly 100 is mounted on a secondary piston 274
disposed within proximal compartment 198 between piston rod 272 and
floating piston 184. Secondary piston 274 has the same
configuration as main piston 102 and thus like reference characters
are used to identify like elements. It is noted, however, that
secondary piston 274 and control valve assembly 100 are rotated
180.degree. relative to the corresponding structures in damper 10.
As such, the proximal and distal orientations are reversed relative
thereto.
[0110] Secondary piston 274 is secured in place by clips 292 which
are received in grooves on interior surface 14 of sidewall 18 so as
to bias against opposing sides of secondary piston 274. In
alternative embodiments, clips 292 can be further spaced apart to
allow some longitudinal sliding of secondary piston 274. In yet
other embodiments, secondary piston 274 can be integrally formed
with housing 12 so as to eliminate the need for seal 114 and clips
292. A shaft 288 extends through secondary piston 274 and control
valve assembly 100 so as to secure the two elements together. Shims
124 bias against proximal face 110 of secondary piston 274 and are
secured thereat by a head 290 of shaft 288 and washer 126. Stop
plate 174 is mounted at the distal end of shaft 288 to control the
distal movement of control valve 106. The combination of secondary
piston 274, control valve 100 and stop plate 174 secured together
by shaft 288 is herein referred to as base valve 286.
[0111] As depicted in FIG. 16, as piston rod 272 advances into
distal compartment 198 of chamber 16, the hydraulic fluid causes
second shims 284 to proximally flex allowing the hydraulic fluid to
travel through compression ports 118 of main piston 102.
Simultaneously, the hydraulic fluid also moves control valve 106 of
control valve assembly 100 into an at least partially open state so
that the hydraulic fluid can pass through compression ports 118 of
secondary piston 274. The hydraulic fluid then pushes floating
piston 184 distally, thereby compressing the gas within distal
compartment 196.
[0112] Depicted in FIG. 17, when the compressive movement of piston
rod 272 has stopped within chamber 16, the fluid pressure within
proximal compartment 198 collapses valve chamber 170, thereby
moving control valve 106 into the closed position. As depicted in
FIG. 18, during the rebound stroke the hydraulic fluid travels
through secondary piston 274 by flowing through pockets 120 and out
through rebound ports 122 by proximally flexing shims 124.
Similarly, the hydraulic fluid travels through main piston 102 by
traveling through pockets 120 and out through rebound ports 122 by
distally flexing shims 282.
[0113] Depicted in FIG. 19 is another alternative embodiment of a
damper 300. Damper 300 includes a double tube housing 302.
Specifically, housing 302 comprises a distal cap 304 and an
opposing proximal cap 306. Extending between caps 304 and 306 and
secured thereto is an outer tube 308. Disposed within outer tube
308 is an inner tube 310 which also extends between opposing caps
304 and 306. Inner tube 310 has an interior surface 312 that bounds
an inner compartment 314. Bounded between the exterior surface of
inner tube 310 and the interior surface of outer tube 308 is an
outer compartment 316. Inner compartment 314 communicates with
outer compartment 316 through a port 318.
[0114] Inner compartment 314 is filled with a hydraulic fluid.
Disposed within outer compartment 316 is an inflatable bladder 320.
Bladder 320 is selectively inflated through a fill valve 322
projecting through outer tube 308. Disposed within the distal end
of inner compartment 314 is base valve 286 as previously discussed
with regard to damper 270 in FIGS. 15-18. In this embodiment,
however, shaft 288 is used to secure base valve 286 directly to
distal end cap 304. It is appreciated that alternative mounting
methods can be used to secure base valve 286 within inner tube 310.
Piston rod 272 with main piston 102, as also discussed with damper
270, are slideably disposed within inner compartment 314.
[0115] As depicted in FIG. 20, damper 300 operates similar to
damper 270. Specifically, as piston rod advances into inner
compartment 314, control valve 106 moves to the open position and
the hydraulic fluid travels through compression ports 118 on both
main piston 102 and secondary piston 274. As the fluid passes
secondary piston 274, the hydraulic fluid enters outer compartment
316 thorough port 318 where it compresses bladder 320. The
hydraulic fluid continues to compress bladder 320 until piston rod
272 is retracted. During retraction, the hydraulic fluid flows back
through main piston 102 and secondary piston 274 in substantially
the same ways as previously discussed with regard to damper 270. In
an alternative embodiment, it is appreciated that bladder 320 can
be replaced with a floating piston which encircles inner tube 310
and slides within outer compartment 316. In yet another
alternative, damper 320 can be inverted and bladder 320 removed. In
this embodiment, a gas, such as air, is trapped within outer
compartment 316. The hydraulic fluid directly contacts the gas,
such as previously discussed with regard to FIG. 11, so as to
selectively compress the gas.
[0116] Depicted in FIG. 21 is one embodiment of shock absorber 350
incorporating features of the present invention. As depicted in
FIGS. 22 and 23, shock absorber 350 comprises a piggy-back housing
352 which includes a primary tube 354, a secondary tube 356 and a
stem 358 extending therebetween. As depicted in FIG. 24 primary
tube 354 has an interior surface 430 bounding a primary chamber 432
while secondary tube 356 has an interior surface 437 bounding a
secondary chamber 438. Returning to FIGS. 22 and 23, stem 358 has a
substantially U-shaped configuration that extends between a first
end 359 and an opposing second end 361. An opening 357 extends
through stem 358 at first end 359 for selective attachment to a
structure.
[0117] Primary tube 354 has an exterior surface 360 extending
between a distal end 362 and an opposing proximal end 364. Distal
end 362 of primary tube 354 is threaded into first end 359 of stem
358. A proximal end cap 366 is threaded into proximal end 364 of
primary tube 360. Adjustably threaded onto distal end 362 of
primary tube 360 is an annular distal spring retention collar
368.
[0118] A piston rod 370 has a distal end 372 (FIG. 24) and an
opposing proximal end 374. A bracket 376 having an opening 378
extending therethrough is threaded onto proximal end 374 of piston
rod 370. Positioned on bracket 376 is an annular proximal spring
retention collar 380. A coiled spring 382 extends between distal
spring retention collar 368 and proximal spring retention collar
380. The tension on spring 382 is selectively adjusted by adjusting
distal spring retention collar 368 along the length of primary tube
354.
[0119] Encircling piston rod 370 between proximal end cap 366 and
proximal spring retention collar 380 is a bottom-out cushion 382.
Cushion 382 is made of a resiliently flexible material such as
rubber or polymeric foam.
[0120] As depicted in FIG. 24, piston rod 370 includes a tubular
base rod 384 and bolt 44 as previously discussed with regard to
damper 10. Base rod 384 has an interior surface 390 bounding a
channel 392 that longitudinally extends between a distal end 386
and an opposing proximal end 388. Bolt 44 is threaded onto distal
end 386 of base rod 384 so that channel 78 of bolt 44 is in fluid
communication with channel 392 of base rod 384. A port 394 extends
through base rod 384 so as to provide fluid communication between
primary chamber 432 of primary tube 354 and channel 78. A pin 396
is slideably disposed within channel 392 of base rod 384. Pin 396
has a tapered nose 398 disposed at the distal end thereof. Nose 398
is configured to complementary fit within the proximal opening of
channel 78 of bolt 44. As a result, pin 396 can be used to
selectively restrict or close off fluid communication between
primary chamber 432 and channel 78 by advancing and retracting pin
396 within base rod 384.
[0121] Bracket 376 has a distal end face 410 having a bore 412
recessed thereon. A passageway 400 transversely extends across
bracket 376 so as to intersect with bore 412. Bracket 376 is
screwed onto base rod 384 such that pin 396 extends down through
bore 412 and partially into passageway 400. A regulator 414 is
adjustably disposed within passageway 400. Regulator 414 includes a
shaft 416 having a distal portion 418 in threaded engagement within
passageway 400 of bracket 376, a substantially frustoconical
transition portion 420, and a substantially cylindrical central
portion 422 formed therebetween. Regulator 414 also includes a
selectively removable knob 424. Selective rotation of knob 424
advances and retracts regulator 414 within passageway 400. As
regulator 414 is advanced within passageway 400, frustoconical
transition portion 420 biases against the distal end of pin 396
causing pin 396 to advance toward bolt 44, thereby restricting or
closing off the proximal opening to channel 78. In turn, as
regulator 414 is retracted, pin 396 is lowered, thereby opening the
flow path to channel 78. Alternative adjustment systems may also be
used to move pin 396.
[0122] Mounted on the distal end of piston rod 370 is main piston
102, control valve assembly 100, and stop plate 174. These elements
are substantially the same as previously discussed with regard to
damper 10 and operate in the same manner. The only distinction is
that control valve assembly 100 of the embodiment shown in FIG. 24
has a slightly different configured valve chamber 170. This is due
to different grooves formed on valve guide 104 and control valve
106.
[0123] Formed at first end 359 of stem 358 is a threaded bore 446.
Distal end 362 of primary tube 360 is threaded within bore 446. A
threaded sleeve 450 projects from an end face 451 at second end 361
of stem 358. A threaded central bore 453 is formed on end face 451.
The distal end of secondary tube 356 is coupled with threaded
sleeve 450. Alternative attachment methods may also be used to
secure primary tube 360 and secondary tube 356 to piggy back
housing 352, including use of a 1-piece forged or cast assembly
which includes all of the aforementioned parts.
[0124] Stem 358 is configured to provide fluid communication
between primary chamber 432 of primary tube 360 and secondary
chamber 438 of secondary tube 356. Specifically, a transition
channel 448 communicates with bore 446 at first end 359 of stem
358. As depicted in FIG. 25, a first valve chamber 452 and a second
valve chamber 454 are each bored into stem 358 from second end 361
toward first end 359. A first pathway 456 extends from first valve
chamber 452 to transition channel 448 while a second pathway 458
extends from second valve chamber 454 to transition channel 448. A
bore 460 intersects with first valve chamber 452 and extends to end
face 451 at second end 361 of stem 358. A bore 462 transversely
intersects with both second valve chamber 454 and central bore 453
so as to provide fluid communication therebetween. A plug 463 is
secured in the opening of bore 462 to prevent fluid from escaping
thereat.
[0125] A first valve 466 is adjustably disposed within first valve
chamber 452. First valve 466 comprises a head 468 having a socket
470 formed on the end thereof to selectively receive a tool for
rotating first valve 466. First valve 466 also has a central body
472 having threads thereon that engage with the inner wall of first
valve chamber 452. One or more seals 474 encircle body 472 and
provide sealed engagement with the inner wall of first valve
chamber 452. Projecting from body 472 is a shaft 474 having a
tapered nose 476. Tapered nose 476 is configured to selectively
engage with the opening to first pathway 456. Accordingly, by
selectively rotating first valve 466, shaft 474 advances or
retracts so as to selectively restrict or open the opening to first
pathway 456.
[0126] A second valve 480 is adjustably disposed within second
valve chamber 454. Similar to first valve 466, second valve 480
comprises head 468, threaded body 472, and seal 474. A piston 482
is movably disposed within second valve chamber 454 at the opening
to second pathway 458. A spring 484 extends between body 472 and
piston 482 so as to bias piston 482 against the opening to second
pathway 458. A rod 486 extends from piston 482, centrally through
spring 484, and freely into a channel 487 formed in the end of body
472. As piston 482 is pushed back, rod 486 is free to retract
within body 472.
[0127] By advancing second valve 480 within second valve chamber
454, spring 484 is compressed, thereby providing greater biasing
force against piston 482. Second pathway 458 is thus only open when
sufficient force is applied to piston 482 to overcome the applied
spring force. Accordingly, by selectively adjusting first valve 466
and second valve 480, dampening properties can be adjusted for
operating conditions.
[0128] Returning to FIG. 24, movably disposed within secondary
chamber 438 is a floating piston 490. Floating piston 490 divides
the enclosed area bounded 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 a
hydraulic fluid while distal compartment 493 is filled with a
compressible gas. Other alternatives as previously discussed can
also be used to replace or use in conjunction with floating valve
490 and the compressible gas.
[0129] Turning 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 interior surface 510 bounding a
channel 512. Central opening 453 and channel 512 provide fluid
communication between second valve chamber 454 and secondary
chamber 438. Alternative attachment methods may be used in place of
bolt 508.
[0130] Encircling bolt 508 and biased against the interior surface
of sleeve 450 is a fixed piston 494 having a configuration similar
to piston 102 as discussed with damper 10. Fixed piston 494 has a
proximal face 496 and an opposing distal face 498. Extending
between faces 496 and 498 are a plurality of radially spaced apart
damping ports 500. A plurality of radially spaced apart pockets 502
are recessed on proximal face 496. A compression port 504 extends
from distal face 498 to each pocket 502.
[0131] A first shim 514 encircles bolt 508 and biases against
proximal face 496. First shim 514 covers the proximal opening of
damping ports 500 but only covers a portion of pockets 502. A
washer 516 encircles bolt 508 and is disposed between shim 514 and
end face 451 of stem 358. Washer 516 provides spacing between end
face 451 and first shim 514 so that first shim 514 can flex
proximal during operation.
[0132] A second shim 518 encircles bolt 508 and biases against
distal face 498 of fixed piston 494. Second shim 518 covers the
distal opening of compression ports 504 but only covers a portion
of the distal openings of damping ports 500. A washer 520 is
disposed between bolt head 509 and second shim 518 to enable 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. As such, the hydraulic fluid passing through
bore 460 must necessarily pass through fixed piston 494 as it
enters secondary chamber 438.
[0133] Depicted in FIG. 24, threaded into the distal end of
secondary tube 356 is a volume adjuster assembly 520. Depicted in
FIG. 27, volume adjuster assembly 520 comprises an annular sleeve
522 having an interior surface 528 and an exterior surface 526.
Sleeve 522 is threaded into the distal end of secondary tube 356.
Adjustably threaded into sleeve 522 is a tubular stem 530. Stem 530
has a proximal end 532 and a distal end 534. Mounted on proximal
end 532 of stem 530 so as to encircle and radially outwardly
project therefrom is a piston 536. Piston 536 is secured to stem
530 by a clip 538 mounted on stem 530 proximal of piston 536.
Piston 536 outwardly projects so as to seal in slideable engagement
against interior surface 437 of secondary tube 356. Distal
compartment 493 is bounded between floating piston 490 and piston
536. By selectively rotating stem 530 relative to sleeve 522, stem
530 and thus piston 536 advance or retract relative to sleeve 522.
Thus by advancing stem 530 and piston 536, distal compartment 493
becomes smaller. In turn the rate at which the gas compresses,
i.e., the compression ratio, within distal compartment 493
increases.
[0134] A cavity 540 is recessed on a distal end face 541 of stem
530. A passageway 542 extends from cavity 540 to a proximal end
face 544 of stem 530. Positioned within cavity 540 in communication
with passageway 542 is a fill valve 546 through which pressured gas
can be fed into distal compartment 493. One example of valve 546 is
a Schrader charge valve. Thus, fill valve 546 can be used to
selectively adjust the gas pressure within distal compartment 493,
thereby adjusting the related dampening properties.
[0135] It is appreciated that shock absorber 350 operates using the
same principals as discussed in detail with regard to the other
embodiments.
[0136] Depicted in FIG. 28 is another alternative embodiment of a
damper 550. Damper 550 has a piggy-back housing 552 comprising a
primary housing 554, a secondary housing 556, and a tubular stem
558 extending therebetween. A sealed hose, pipe, or other conduit
may be substituted for stem 558 for establishing fluid
communication between primary housing 554 and secondary housing
556. Primary housing 554 is the same as housing 12 previously
discussed with regard to damper 10 except for the attachment of
stem 558. Furthermore, as also discussed with damper 10, coupled
with primary housing 554 is piston rod 34 having a main piston 102,
control valve assembly 100, and stop plate 174 mounted thereon. As
such like elements between damper 550 and damper 10 are identified
by like reference characters.
[0137] Secondary housing 556 comprises a tubular, cylindrical
sidewall 560 extending between a proximal end 562 to an opposing
distal end 564. Proximal end 562 terminates at a proximal end wall
563. Threadedly disposed within distal end 564 of secondary housing
556 is volume adjuster assembly 520 as previously discussed with
regard to FIG. 25. Alternative methods for attaching volume
adjustor assembly 520 can be used. Sidewall 560 has an interior
surface 566 that bounds a secondary chamber 568 extending between
proximal end wall 563 and piston 536 of volume adjuster assembly
520. Tubular stem 558 bounds a channel 576 that extends between
primary chamber 16 and secondary chamber 568. Primary chamber 16,
secondary chamber 568, and channel 576 of stem 558 combine to form
a total chamber 578.
[0138] Inwardly projecting from sidewall 560 at proximal end 562 of
secondary housing 556 is a retaining wall 570. Slideably disposed
within secondary chamber 568 distal of retaining wall 570 is a
floating piston 574. Floating piston 574 divides total chamber 578
into a proximal compartment 580 and a distal compartment 582.
Proximal compartment 580 is filled with a hydraulic fluid while
distal compartment 582 is filled with a compressible gas.
[0139] Disposed between retaining wall 570 and proximal end wall
563 of secondary housing 556 is a base valve 586. Depicted in FIG.
29 is an enlarged cross sectional view of base valve 586. As
depicted therein, base valve 586 comprises a secondary piston 584
having compression ports 118 and rebound ports 122 extending
therethrough. A tubular shaft 583 extends through secondary piston
584 and beyond the proximal face thereof. A washer 585 encircles
shaft 583 so as to cover the openings to rebound ports 122 while
leaving the openings to compression ports 118 open. A retention
collar 587 is threaded onto the proximal end of shaft 583. A spring
588 extends between retention collar 587 and washer 585 so as to
bias washer 585 against the openings to rebound ports 122. Washer
585 and spring 588 function as a one-way check valve to regulate
the fluid flow through rebound ports 122 and are an alternative
embodiment to the flexible shims as discussed in other
embodiments.
[0140] Disposed against the distal face of secondary piston 584 and
encircling tubular shaft 583 is control valve assembly 100. Control
valve assembly 100 controls the fluid flow through compression
ports 118 in substantially the same method of operation as
discussed in the other embodiments. That is, based on the force of
the fluid passing through compression ports 118 and the pressure of
the hydraulic pressure, control valve assembly 100 is moved to some
extent between the open position shown in FIG. 30 and the closed
position shown in FIG. 31. Unlike the prior embodiments, however,
control valve assembly 100 can be selectively adjusted through the
application of a spring force.
[0141] Specifically, a collar 589 is inserted within secondary
housing 556. Collar 589 encircles tubular shaft 583 so that an
annular spring cavity 591 is formed therebetween. Disposed within
spring cavity 591 is an annular first bias plate 592 disposed
against control valve 106 and an annular second bias plate 593
disposed against a portion of collar 589. A spring 594 extends
between bias plates 592 and 593 so as to bias first bias plate 592
against control valve 106. Posts 595 extend from second bias plate
593 to an 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
greater force is applied to control valve 106, thereby altering the
operation thereof.
[0142] To enable the hydraulic fluid to access the distal side of
control valve assembly 100, a fluid path 597 extends through shaft
583 and communicates with spring cavity 591 and chamber 581. Ports
598 are formed on first bias plate 592 so as to enable the
hydraulic fluid to directly contact 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 591 and chamber 581, a pin 599 is
threadedly disposed within fluid path 597 so as to selectively
constrict fluid path 597.
[0143] FIG. 30 shows the flow path of the hydraulic fluid as piston
rod 34 is advanced within primary chamber 16. FIG. 31 shows the
flow path of the hydraulic fluid as piston rod 34 is retracted out
of primary chamber 16.
[0144] Depicted in FIG. 32 is a damper 600 that is substantially
identical to damper 550. Damper 600 is distinguished over damper
550 in that floating piston 574 has been replaced with a flexible
diaphragm 602.
[0145] Depicted in FIG. 33 is another alternative embodiment of a
damper 610 that is similar to damper 550. Damper 610 is
distinguished over damper 550 in that base valve 586 which contains
a control valve assembly 100 has been replaced with a conventional
base valve 612 that does not incorporate a control valve assembly
100.
[0146] Depicted in FIGS. 34 and 35 is one embodiment of how an
inventive damper can be incorporated into a front fork of a
bicycle, motorcycle, or the like. Specifically, depicted in FIG. 34
is a front fork 630 having an upper tube 632 slideably received
within a lower tube 634. Disposed within lower tube 634 so as to
resiliently bias against upper tube 632 is a spring 633. Spring 633
provides the rebound force for the damper and can be positioned at
different locations. Alternative methods of producing a rebounding
force may also be used, i.e., compressed gas, microcellular foam,
and the like. Disposed within upper tube 632 is a tubular cartridge
636 which bounds a chamber 638. A tubular piston rod 640 has a
proximal end 642 mounted on a base floor of lower tube 634 and an
opposing distal end 644 slideably extending up through upper tube
632 and cartridge 636. Mounted within chamber 638 on distal end 644
of piston rod 640 is main piston 102, control valve 100, and stop
plate 174 as previously discussed with regard to damper 10 in FIGS.
1-7.
[0147] Rebound channel 88, as disclosed with regard to damper 10,
is also formed on piston rod 640 so as to extend between opposing
sides of main piston 102. In contrast to rebound channel 88 for
damper 10, however, in the embodiment depicted in FIG. 34 a
regulating pin 641 having a tapered nose is movably disposed within
piston rod 640. That is, by selectively rotating regulating 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
channel 88, the slower the rebound of piston rod 640.
[0148] Screwed into the distal end of cartridge 636 is a hollow
sleeve 646. In turn, screwed into sleeve 646 is an end plug 648
having a stem 650 proximally projecting therefrom within chamber
638. A first piston 652 encircles and is slideably disposed on stem
650. First piston 652 forms a sealed engagement with stem 650 and
cartridge 636. As such, first piston 652 forms a barrier that
divides chamber 638 into a relative proximal chamber 654 and a
relative distal chamber 656. Proximal chamber 654 is filled with a
hydraulic fluid while distal chamber 656 is filled with a
compressible gas such as air.
[0149] Mounted against end plug 648 so as to also encircle stem 650
is a second piston 660. Second piston 660 is also in sealed
engagement with stem 650 and cartridge 636. By rotating end plug
648, second piston 660 advances into distal chamber 656 effectively
decreasing the size of distal chamber 656. This also increases the
pressure within both proximal chamber 654 and distal chamber 656
and the compression ratio within distal chamber 656.
[0150] A fill valve 662 is mounted on end plug 648. A passageway
664 extends through end plug 648 from fill valve 662 to distal
chamber 656. As such, fill valve 662 can be used to selectively
adjust the volume and pressure of gas within distal chamber
656.
[0151] Finally, although not required, a 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, except for having a solid center, has
substantially the same configuration as main piston 102.
Specifically, base valve piston 668 has compression ports 118 and
rebound ports 122 extending therethrough. Flexible shims 670 and
672 are mounted on opposing sides of base valve piston 668, as
previously 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 transfer of pressure which partially
controls the damping properties.
[0152] FIG. 35 shows front fork 630 with piston rod 640 being
advanced into chamber 638.
[0153] The use of cartridge 636 as discussed above with regard to
front fork 630 is for ease in manufacture and assembly. The use of
cartridge 636 also enables the dampers of the present invention to
be retrofit into existing forks. Depicted in FIG. 36, however, is a
front fork 676. Front fork 676 is the same as front fork 630 except
that cartridge 636 has been removed. FIG. 37 shows front fork 676
with piston rod 640 being advanced into chamber 638 while FIG. 38
shows front fork 676 with piston rod 640 being withdrawn from
chamber 638.
[0154] It is appreciated that all of the different damping
configurations disclosed herein can be incorporated in a front
fork. As a further example, depicted in FIGS. 39 and 40 is a front
fork 680 where control valve 100 has been moved from main piston
102 to base valve piston 668. This system operates similar to the
damper discussed with regard to FIGS. 15-18.
[0155] The above discussed dampers of the present invention provide
automatic adjustment of damping properties based on operating
conditions, thereby optimizing damping. Different embodiments
provide for a variety of selective manual damping adjustments
and/or remote damping adjustments. Such adjustability enables the
dampers to be effectively used in a variety of different conditions
and on a variety of different vehicle or other systems. The design
of the dampers also facilitates ease in manufacture and
assembly.
[0156] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. For example, disclosed herein are numerous
examples of different dampers having different features for
controlling damping properties. It is appreciated, however, that
the different features can be mixed and matched so as to form a
variety of other unique assemblies. Accordingly, the described
embodiments are to be considered in all respects only as
illustrative and not restrictive. The scope of the invention is,
therefore, indicated by the appended claims rather than by the
foregoing description. All changes which come within the meaning
and range of equivalency of the claims are to be embraced within
their scope.
* * * * *