Hydraulic line coupling apparatus for hydraulic shock absorber

An apparatus for coupling two hydraulic transmission lines to one another is disclosed. The apparatus comprises a first coupling member and a second coupling member. The first coupling member comprises a body having first and second passages. The first passage extends from the connection to the first line to the second passage. A plug is movably positioned in the first passage for selectively opening and closing the first passage between the first line and the second passage. A first and second passage similarly extends through the second coupling member, and a plug is movably positioned in the first passage for selectively opening and closing the first passage between the second line and the second passage. The first and second coupling members are selectively joinable via a sleeve extending between the second passages thereof.

FIELD OF THE INVENTION 
The present invention relates to a hydraulic shock system of the type used 
with a vehicle, the system including coupling apparatus for readily 
coupling and uncoupling components of the system. 
BACKGROUND OF THE INVENTION 
Hydraulic shock absorber systems are common on automobiles and other 
vehicles. These systems generally comprise an oil-filled shock absorber 
mounted between the suspension of each wheel of the vehicle and the 
vehicle frame. A hydraulic supply is centrally located between two or more 
of the shock absorbers. The hydraulic supply is connected to the shock 
absorbers via tubes or lines which carry hydraulic oil. 
During vehicle assembly, the hydraulic system is generally assembled 
separate from the vehicle on which it is ultimately installed. In this 
process, the entire hydraulic system is assembled and filled with oil. The 
system is checked for leaks and the damping is adjusted. 
The assembled system is then transported to the vehicle assembly line and 
installed onto the vehicle. Due to the overall size of the system, 
transporting and installing the system is difficult and requires a great 
many workers. As one attempt at solving the installation problems 
associated with these systems, it is possible to disassemble the system 
and reassemble it on the vehicle. This also has numerous disadvantages. 
First, the oil must be drained from the system upon disassembly and be 
replaced once the system is reassembled on the vehicle. Once the system is 
installed on the vehicle, however, it is difficult to refill the system 
with oil as access to the system is often obstructed by other components 
of the vehicle. In addition, leaks are often created during the 
disassembly/reassembly process. 
Another problem associated with the present systems is that, after 
installation of the system on the vehicle, later repair is difficult and 
costly. The same problems which render disassembly of the system for 
installation on the vehicle undesirable make it difficult to repair 
individual components of the system later. 
A hydraulic shock system which includes coupling apparatus designed for 
individual component coupling and uncoupling is desirable. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a coupling apparatus is provided 
for coupling hydraulic oil transmission lines. The coupling apparatus 
allows a user to selectively couple and uncouple the lines. The coupling 
apparatus allows for uncoupling of the lines while the fluid is retained 
within the lines. 
The coupling apparatus includes a first coupling member attached to a first 
hydraulic oil transmission line and a second coupling member attached to a 
second hydraulic oil transmission line. The first coupling member 
comprises a body having a passage therethrough, a first end of which is in 
communication with the first line. A second passage extends from the first 
passage through the body. A valve is provided for selectively closing the 
first passage between the connection to the first line and the second 
passage. 
The second coupling member comprises a similar body having a first passage 
therethrough, a first end of which is in communication with said second 
line. A second passage extends from the first passage through the body. A 
valve is provided for selectively opening and closing the first passage 
between the connection of the second line and the second passage. The 
first and second coupling members are coupled and uncoupled by guiding a 
sleeve into and out of the second passages of the first and second 
coupling members. 
In accordance with a further aspect of the present invention, coupling 
apparatus is provided which allows a user to selectively couple and 
uncouple a hydraulic oil transmission line to a shock absorber without 
removing the oil in the line or shock absorber. 
The shock absorber has a piston rod extending therefrom. The piston rod has 
a passage therethrough extending from a first end of the rod to an oil 
filled chamber in the shock absorber. The rod includes valve means for 
selectively opening and closing the passage. 
A coupling member has a first section and a second section, the first 
section having a chamber therein in which the first end of the rod is 
positioned. The second section has a passage therethrough, the passage 
extending from the chamber in the first section to the hydraulic oil 
transmission line. Valve means are provided for selectively opening and 
closing the passage in the second section between the chamber in the first 
section and the line. 
Further objects, features, and advantages of the present invention over the 
prior art will become apparent from the detailed description of the 
drawings which follows, when considered with the attached figures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1(a) illustrates a coupling apparatus 30 in accordance with the 
present invention utilized in a hydraulic shock absorber system 20. The 
system 20 described with the coupling apparatus 30 herein is for 
illustration only, it being understood that the coupling apparatus 30 has 
utility in numerous other systems varying from that illustrated in FIG. 1 
and described herein. 
In general, the system 20 of the type utilized on a vehicle includes at 
least one hydraulic shock absorber 22, a hydraulic oil pressure 
regulator/supply 24, and a hydraulic oil transmission line extending 
between each shock absorber and the hydraulic pressure regulator. 
Normally, these transmission lines comprise a first line 26 extending from 
the shock 22 and a second line 28 extending from the regulator 24. In 
accordance with the present invention, a coupling apparatus 30 is provided 
for sealingly coupling these lines 26,28 and for uncoupling the lines 
without the need for removing the oil in the system. 
FIG. 1(b) illustrates the hydraulic shock absorber 22 utilized in the 
system 20. These types of shocks 22 are well known to those skilled in the 
art. The shock 22 has an outer cylindrical housing 32 having an end for 
connection to the suspension assembly of a wheel of a vehicle. The shock 
22 includes a piston rod 34 having a piston head 35 at one end positioned 
in the housing 32, and a second end extending beyond the housing for 
connection to the frame of a vehicle. The piston head 35 divides the 
interior of the housing 32 into a first oil chamber 36 and a second oil 
chamber 38. The first and second oil chambers 36,38 communicate through a 
constricted passage 40 extending through the piston head 35. The first 
line 26 extends from the shock 22, the line 26 in communication with the 
second oil chamber 38. 
FIG. 1(c) illustrates the hydraulic pressure regulator/supply 24 utilized 
in the system 20. The hydraulic pressure regulator/supply 24 is of the 
type well known to those skilled in the art. The regulator 24 comprises a 
housing 42 defining an interior chamber. A first piston 44 is positioned 
within the housing 42. The first piston 44 divides the interior chamber of 
the housing 42 into an air chamber 46 and a first oil chamber 48. A second 
piston 50 is positioned within the first oil chamber 48. The second piston 
50 is attached to the first piston 44 so that the first and second pistons 
44,50 move together. The second piston 50 defines therebehind a second oil 
chamber 52. A constricted passage 54 extends through the second piston 50 
such that the first and second oil chambers 48,52 are in communication 
with one another. 
One hydraulic line 28 corresponding to one shock 22 is mounted in 
communication with the first oil chamber 48. A second hydraulic line 28 
corresponding to another shock 22 is mounted in communication with the 
second oil chamber 50. 
FIG. 1(a) illustrates a common hydraulic shock absorber system 20 
arrangement for a vehicle, in which a first shock 22 is mounted at one 
side of the vehicle between the suspension assembly of a wheel and the 
frame of the vehicle, and a second shock 22 is mounted at the opposite 
side of the vehicle between the suspension assembly of an opposite wheel 
and the frame of the vehicle. In this arrangement, there are thus left and 
right shock absorbers corresponding to left and right wheels of the 
vehicle. 
The hydraulic regulator 24 is generally mounted between the shock absorbers 
22 to the frame of the vehicle. The second lines 28 extend from the 
hydraulic pressure regulator 24 in opposite directions towards the shocks 
22. The first lines 26 extending from each shock 22 engage a respective 
second line 28 such that a continuous hydraulic oil pathway is formed 
between the hydraulic pressure regulator 24 and each shock 22. 
Most commonly, the transmission lines 28 extending from the hydraulic 
pressure regulator 24 are constructed of metal tubing. These lines 28 are 
connected to the frame of the vehicle by one or more brackets 56. The 
transmission lines 26 connected to the shocks 22 normally comprise 
flexible high strength hose. 
As stated above, a coupling apparatus 30 is provided in accordance with the 
present invention for coupling and uncoupling the first and second 
hydraulic oil transmission lines 26,28. As best illustrated in FIGS. 2 and 
3, the coupling apparatus 30 comprises a first coupling member 58 attached 
to the free end of each first line 26 (i.e. opposite its connection to the 
shock 22) and a second coupling member 60 attached to the free end of each 
second line 28 (i.e. the end of the line 28 opposite its connection to the 
hydraulic regulator 24). The first and second coupling members 58,60 are 
designed for interengagement so that a continuous oil pathway is formed 
through the lines 26,28 between the shock 22 and the hydraulic pressure 
regulator 24. 
The second coupling member 60 includes a generally cylindrical body 62 
having a first outwardly extending flange 64 and a second outwardly 
extending flange 66. The first and second flanges 64,66 are generally 
flat. The first flange 64 is adapted for use in attaching the first and 
second coupling members 58,60 to one another via a bolt 68. The second 
flange 66 is adapted for mounting the member 60 to a vehicle frame member 
72 via a similar bolt 70. 
An elongate passage 74 extends through the body 66 of the second coupling 
member 60 from one end to the other. As illustrated in FIG. 3, the second 
line 28 is mounted in communication with the passage 74 at one end of the 
member 60. 
The second coupling member 60 includes valve means for selectively opening 
and closing the passage 74. Preferably, the valve means comprises a plug 
76 positioned within the passage 74 at the end opposite the line 28. The 
plug 76 includes a threaded portion for engagement with threads on the 
body 66 within the passage 74. Opposite its threaded end, the plug 76 has 
a reduced diameter section leading to a tapered end 78. The tapered end 78 
is configured for abutment against a shoulder 80 formed by a reduced 
diameter section of the passage 74. The threaded end of the plug 76 
includes a recess 84 for engagement by a tool. The recess 84 may be 
hexagonal in shape for engagement with an Allen wrench or similar tool. 
The plug 76 is adapted for movement inside of the member 60 along the 
passage 74. A locking ring 82 is positioned within the passage 74 for 
preventing removal of the plug 76 from the member 60. FIG. 3 illustrates 
the plug 76 in a retracted or open position. As also illustrated therein 
in dotted lines, the plug 76 may be screwed forward into a closed position 
in which its tapered end 78 engages the shoulder 80 and obscures the 
passage 74. 
When the plug 76 is moved to its open position, a chamber 86 exists in the 
member 60. During use of the system 20, this chamber 86 fills with 
hydraulic oil. Oil is prevented from leaking from the chamber 86 past the 
plug 76 with an "O"-ring 88. 
An end cap 90 covers the end of the body 66 of the member 60 when the plug 
76 is in its open position. The end cap 90 includes an outwardly extending 
flange 92 for abutment against the end of the body 66 of the member 60. In 
addition, the cap 90 includes a downwardly extending flange 94 for fitting 
into the recess 84 of the plug 76. The distance "d" by which the cap 90 
engages the plug 76 is less than the maximum travel distance of the plug 
76 in the passage 74. In this fashion, when the plug 76 is in its closed 
position, the cap 90 will not engage the plug 76 and can not be placed 
over the end of the body 66. 
The second member 60 includes a bore 96 extending generally perpendicular 
to the first passage 74 through the body 66. When the plug 76 is in its 
open position, this bore 96 is in communication with the chamber 86 and 
the line 28. 
The first coupling member 58 is substantially similar to the second member 
60. As illustrated in FIG. 2, the first member 58 includes a generally 
cylindrical body 98. A flange 100 extends from the body 98. The flange 100 
is adapted for engagement with the flange 64 of the second member 58 via 
the bolt 68 described above. 
The first coupling member 58 includes a passage 74 therethrough, a plug 76, 
an end cap 90, a locking ring 82, a recess 84 in the end of the plug, a 
tapered plug end 78, a shoulder 80, and an "O"-ring 88. The first 
hydraulic line 26 engages the end of the coupling member 58 opposite the 
plug 76 and is in communication with the passage 74. 
As illustrated, the first and second coupling members 58,60 are arranged 
such that the first and second hydraulic lines 26,28 extend therefrom 
parallel to, but on opposite ends 180 degrees from one another. While this 
arrangement is preferred, the first and second coupling members 58,60 
could be designed to engage one another in other orientations, such as 
where the lines 26,28 enter the same side or are oriented perpendicular to 
one another. 
When the plug 76 of the first coupling member 58 is in its open position, 
there is formed in the member 58 a chamber 101. A bleed passage 102 
extends from the passage 74 in the first coupling member 58 through the 
body 98. A screw 104 is positioned in the bleed passage 102 for 
selectively opening and closing the passage 102. 
A bore 106 is provided opposite the bleed passage 102. The bore 106 extends 
through the body 98 of the first member 58 from the passage 74 and 
generally perpendicular to the passage. The bore 106 is in communication 
with the first passage 74 such that a hydraulic oil passage is provided 
from the bore 106 to the chamber 101, down the first passage 74, and into 
the first transmission line 26 when the plug 76 is in its open position. 
The bore 106 is positioned in the body 98 such that it aligns with the 
bore 96 in the second coupling member 60. 
A connecting sleeve 108 extends between the bore 106 in the first coupling 
member 58 and the bore 96 in the second coupling member 60 when the two 
members 58,60 are joined. Preferably, one end of the sleeve 108 is 
press-fit into the bore 96 in the body 66 of the second coupling member 
60. The opposite end of the sleeve 108 is designed to slide into the bore 
106 in the first coupling member 58. Another "O"-ring 110 is positioned in 
this bore 106 for preventing leakage between the body 98 and the sleeve 
108 when the first and second coupling members 58,60 engage one another. 
The coupling apparatus 30 of the present invention allows the first and 
second transmission lines 26,28 to be coupled and uncoupled from one 
another. Assembly of a complete hydraulic system utilizing the coupling 
apparatus 30 of in accordance with the present invention is as follows. 
First, all of the components of the system 20 are assembled. The first line 
26 extending from each shock 22 is coupled to the second line 28 extending 
from the hydraulic pressure regulator 24. In this process, the first 
coupling member 58 is pressed downwardly such that the sleeve 108 extends 
upwardly into the bore 108 past the "O"-ring 110. The bolt 68 is utilized 
to maintain the two members 58,69 coupled to one another. 
Hydraulic oil is filled into the system 20 and the system bled to remove 
air therefrom. When oil is filled into the system 20, the plugs 76 are 
moved to their open positions. With the plugs 76 in their open position, 
oil passes from the first to the second line 26,28 or vice versa through a 
continuous passage through the first and second coupling members 58,60. 
The passage through the first coupling member 58 comprises the passage 74, 
the chamber 101 and the bore 106. The passage through the second coupling 
member 60 comprises the passage 74, the chamber 86 and the bore 96. Once 
filled, the system 20 may then be checked for leaks and the damping 
adjusted. 
Advantageously, the system 20 may then be disassembled for transport and 
then reassembled without removing the oil from the system. The coupling 
assembly 30 allows for separation of the shocks absorbers 22 from the 
hydraulic pressure regulator 24. In order to uncouple the first line 26 
from the second line 28, the plug 76 in the second coupling member 60 is 
screwed inwardly until it closes off the passage 74 when the tapered end 
78 abuts the shoulder 80. Next, the plug 76 in the first coupling member 
58 is screwed inwardly until it closes of the similar passage 
therethrough. At that time, the two coupling member 58,60 may be separated 
without needing to remove the oil from the system 20. 
Each component of the system 20 is then transported and installed onto the 
vehicle. Once the system 20 has been broken into components, a single 
worker can easily transport and install the system 20. The second 
transmission lines 28 are attached to the vehicle using the brackets 56 
described above, and the second coupling members 60 are attached to the 
vehicle with the bolts 70. The shocks 22 are installed onto the vehicle. 
Once the individual components have been installed, the lines 26,28 are 
recoupled with the coupling apparatus 30 of the present invention. The 
first and second coupling members 58,60 are coupled as described above. 
Next, the plug 76 in the second coupling member 60 is screwed backwardly 
into its retracted or open position. Hydraulic oil expands into the 
chamber 86 and up through the bore 96 and sleeve 108. As some air likely 
remains in this portion of the system, the bleed screw 104 is opened until 
the air is relieved. This step is accomplished before the plug 76 in the 
first coupling member 58 is opened. Once all the air is bled off, this 
plug 76 is moved to its open position. 
FIGS. 4-8 illustrate a coupling apparatus 130 in accordance with a second 
aspect of the present invention. This coupling apparatus 130 is adapted 
for use in coupling a hydraulic line to a hydraulic shock absorber. This 
aspect of the present invention may be used with a system 20 including the 
coupling apparatus 30 disclosed above. Alternatively, the coupling 
apparatus 130 may be used in a system which does not include the coupling 
apparatus 30 disclosed above. By way of illustration, the coupling 
apparatus 130 is described as utilized with a system 20 as described above 
and illustrated in FIG. 1(a). 
As illustrated in FIG. 4, the shock 22 has an elongate, generally 
cylindrical outer housing 132 having a hollow interior. The shock absorber 
22 includes a rod 136 having a first end extending out of the housing 132 
and a second end having a piston head 138 thereon positioned within the 
interior of the housing. The piston head 138 divides the interior into a 
first chamber 134 and a second chamber 140. 
A first end of the shock 22 is adapted for connection to the suspension 
assembly of a wheel of a vehicle. A second end of the shock 22 is adapted 
for connection to a vehicle mounting 142. The first end of the rod 136 
extends through a passage 144 in the mounting 142. The rod 136 is 
maintained in engagement with the mounting 142 via a nut 146. A coil 
spring 148 extends about the top portion of the shock 22. 
A passage 150 extends through the length of the rod 136. The passage 150 
communicates, at one end, with the second chamber 140. Two cross-bores 158 
extend perpendicular to one another and the length of the rod 136 near the 
top end of the rod 136. The bores 158 communicate with the passage 150. 
Valve means are provided for selectively opening and closing the passage 
150 in the rod 136. Preferably, this valve means comprises a plug 160 
extending into the passage 150 at the top end of the rod 136. The plug 160 
is threaded at one end for engagement of threads in the passage 150 of the 
rod 136, whereby the plug 160 may be screwed in and out of the rod 136 
along the passage 150. A locking ring 162 prevents the plug 160 from being 
removed from the rod 136. An "O"-ring 164 serves as a seal between the 
plug 160 and the rod 136 within the passage 150. 
The plug 160 has a reduced diameter section in relation to the passage 150 
and then a tapered end 166 opposite its threaded end. The tapered end 166 
is designed to engage a shoulder 170 formed by a reduced diameter section 
of the passage 150 within the rod 136. 
In accordance with the present invention, a coupling member 152 is provided 
for coupling the first line 26 in communication with the passage 150 
through the rod 136 of the shock 22. As illustrated in FIGS. 5-8, the 
coupling member 152 has a first generally cylindrical section 154 and a 
second generally cylindrical section 156 extending therefrom. 
As best illustrated in FIG. 7, the first section 154 has a hollow interior 
which accepts the end of the rod 136 in which the plug 160 is positioned. 
The coupling member 152 is secured onto the rod 136 via a screw 172 which 
extends transversely through the coupling member 152 and engages a 
recessed area 174 in the outer surface of the rod 136. 
The hollow interior of the first section 154 includes an enlarged section 
or chamber 176. When the plug 160 is in the position illustrated in FIG. 
7, the passage 150 within the rod 136 is in communication with the chamber 
176 via the cross-bores 158. 
First and second "O"-rings 178,180 are positioned within the coupling 
member 152 for engagement of the outer surface of the rod 136 for 
preventing leakage. A bleed screw 182 extends into a bleed passage in 
communication with the chamber 176. 
An end cap 184 is provided for covering the otherwise open end of the first 
section 154 of the coupling member 152 at the plug 160. The end cap 184 
includes an outwardly extending flange 186 and another section for 
extension into a recess 188 in the end of the plug 160. This recess 188 is 
preferably hexagonal in shape for engagement with an Allen wrench or 
similar tool. As with the caps 90 described above, this cap 184 is 
preferably designed such that it will not engage the plug 160 when the 
plug is screwed inwardly to its closed position. 
The second section 156 of the coupling member 152 extends as a branch off 
of the first section 154. As illustrated in FIG. 7, the second section 154 
has a passage 190 extending therethrough, the passage 190 in alignment 
with the chamber 176 within the first section 154. 
The second section 156 includes valve means for selectively opening and 
closing the passage 190 therethrough. Preferably, this means comprises a 
plug 192 positioned in the passage 190 of the second section 156. The plug 
192 has a first end which is threaded for engagement with threads within 
the second section 156. Opposite its threaded end, the plug 192 has a 
reduced diameter section and a tapered end 194. The tapered end 194 of the 
plug 192 is designed for engagement with a shoulder 196 extending into the 
passage 190. 
An "O"-ring 198 is positioned on the outside surface of the plug 192 for 
sealing the plug 192 within the passage 190. The threaded end of the plug 
192 includes a recessed area 200. The recessed area 200 is preferably 
hexagonal in shape for engagement with an Allen wrench. A locking ring 202 
is positioned near the end of the passage 190, preventing removal of the 
plug 192 from the second section 156. A cap 204 similar to the cap 184 
described previously is utilized to cover the open end of the second 
section 156 when the plug 192 is in its open position. 
When the plug 192 is in its retracted or open position, a chamber 206 
exists in the second section 156. The first transmission line 26 
communicates with the chamber 206 through a port 208 in the second section 
156. Preferably, a fitting 210 is positioned on the end of the 
transmission line 26 and engages the port 208. 
As illustrated in FIG. 7, when the plugs 160,192 are in their retracted or 
open positions, a hydraulic oil flow path is formed from the first 
transmission line 26 to the second chamber 140 within the shock 22. This 
flow path extends from the line 26, through the port 208 into the chamber 
206 in the second section 156 of the coupling member 152, into the chamber 
176 of the first section 154 of the coupling member 152, and through the 
cross-bores 158 and along the passage 150 in the rod 136 to the chamber 
140. 
Advantageously, the coupling apparatus 130 of the present invention allows 
the first transmission line 26 to be easily connected and disconnected 
from the shock 22 without the need to drain the oil from the line or the 
shock. To separate the line 26 from the shock 22, the plug 160 in the 
first section 154 of the coupling member 152 is screwed inwardly until its 
tapered end 166 engages the shoulder 170, closing off the passage 150 
through the rod 136. At this time, oil is prevented from leaking from the 
shock 22. Next, the plug 192 in the second section 156 of the coupling 
member 152 is screwed inwardly until its tapered end 194 engages the 
shoulder 196. At this time, oil is prevented from flowing through the line 
26 and out of the coupling member 152. The coupling member 152 is 
separated from the shock 22 by removing the screw 174 and then lifting the 
coupling member 152 upwardly off of the rod 136 of the shock 22. 
Coupling of the line 26 to the shock 22 is generally in the reverse order 
of disassembly. First, the first section 154 of the coupling member 152 is 
pushed downwardly over the top end of the rod 136 and affixed thereto 
utilizing the screw 174. The plug 192 in the second section 156 of the 
coupling member 152 is then unscrewed. The bleed screw 182 is then opened 
to bleed any air out of the system. The plug 160 in the first section 154 
of the coupling member 152 is then unscrewed. Once the plugs 160,192 are 
in their unscrewed or open positions as illustrated in FIG. 7, the caps 
184,204 may be reinstalled. 
It will be understood that the above described arrangements of apparatus 
and the method therefrom are merely illustrative of applications of the 
principles of this invention and many other embodiments and modifications 
may be made without departing from the spirit and scope of the invention 
as defined in the claims.