Land vehicles – Wheeled – Attachment
Reexamination Certificate
2001-01-11
2004-11-02
Lavinder, Jack (Department: 3683)
Land vehicles
Wheeled
Attachment
C267S064160
Reexamination Certificate
active
06811171
ABSTRACT:
RELATED APPLICATIONS
This application is related to Japanese Patent Application No. 2000-002597, filed on Jan. 11, 2000, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to vehicle suspension systems. More particularly, the present invention relates to interrelated multiwheel suspension systems that provide improved damping when a vehicle rolls or pitches and a single wheel encounters a bump.
2. Description of Related Art
Vehicles often comprise suspension systems that smooth operation over uneven or rough terrain. The suspension systems often involve placing a damper between the vehicle and the surface contacting member, such as a wheel. An example of a suspension system used in four-wheel vehicles has been disclosed in Japanese laid open patent application No. HEI-6-62127. Reproduced as
FIGS. 1-3
in the present application are figures that disclose a construction similar to that disclosed in that laid open application.
With reference now to
FIGS. 1-3
, three alternative constructions of a suspension system will be described. The suspension system, indicated generally by the reference numeral
20
, comprises a front left damper
22
, a front right damper
24
, a rear left damper
26
, and a rear right damper
28
. In the illustrated arrangement, each of the dampers is constructed identical to the others. In particular, in the illustrated arrangement, an outer cylinder
30
is divided into an upper chamber
32
and a lower chamber
34
by a piston
36
. The piston
36
is slidably mounted within the inner bore of the outer cylinder
30
. In addition, the piston comprises at least one passage
38
which extends through the body of the piston
36
to place the upper chamber
32
and the lower chamber
34
in fluid communication with each other. A throttle
40
preferably is disposed within the passage
38
to control the flow rate through the passage
38
of fluid from the upper chamber
32
to the lower chamber
34
, and vice versa. Of course, more than one passage can be used and such passages can be configured with valves that limit flow to one direction. Such a configuration allows varying damping rates between the two different directions of piston movement. In the illustrated arrangement, the piston
36
is mounted to a piston rod
42
. One of the piston rods
42
and the cylinder
30
is connected to the vehicle body while the other of the two members is connected to the wheel. In this manner, movement between the wheel and the vehicle body can be controllably damped by movement of the piston
36
within the bore of the outer cylinder
30
.
With continued reference to
FIGS. 1-3
, each of the cylinders
22
,
24
,
26
,
28
is directly interconnected through the use of a pressure regulator
44
.
FIGS. 1-3
illustrate four different arrangements of the pressure regulator
44
and the interconnection between the cylinders
22
,
24
,
26
,
28
. Depending upon the interconnection used, the suspension systems
20
exhibit varying response characteristics to movement of the vehicle.
With reference now to
FIG. 1
, the illustrated pressure regulator
44
generally comprises a pair of parallel lower chambers
46
,
48
. The first lower chamber
46
is defined within a first cylinder
50
, while the second lower chamber
48
is defined within a second cylinder
52
. A first piston
54
subdivides a portion of the first cylinder
50
into the first lower chamber
46
while a second piston
56
subdivides a portion of the chamber or the cylinder
52
into the second lower chamber
48
. The pistons
54
,
56
are connected together with the use of a single connecting rod
58
that ties the pistons
54
,
56
together for movement. In other words, the connecting rod
58
ensures that the pistons
54
,
56
travel together. In the illustrated arrangement, the connecting rod
58
is disposed within a chamber
60
that is defined within the pressure regulator
44
. The chamber
60
preferably is filled with an inert gas. The inert gas exerts a pressure against the pistons
54
,
56
to drive the pistons into a desired equilibrium position. A passage
62
containing a throttle valve extends between the first lower chamber and the second lower chamber
48
. The passage
62
contains the throttle to allow damping to occur when fluid flows from one chamber to the other chamber.
The pressure regulator illustrated in
FIG. 2
has a construction similar to that illustrated in FIG.
1
. However, the pressure regulator
44
illustrated in
FIG. 3
contains two additional chambers
64
,
66
that are interconnected in parallel by two additional throttled passages
68
,
70
. The chambers
64
,
66
are also defined, in part, by a pair of pistons
72
,
74
that are interconnected with the connecting rod
68
.
Functionally, the suspension systems
20
illustrated in
FIGS. 1-3
operate differently depending upon the loads and relative movements of the vehicle. For instance, in the arrangement illustrated in
FIG. 1
, both of the dampers
22
,
26
on the left side of the vehicle are interconnected to a single chamber of the pressure regulator
44
while both of the dampers
24
,
28
on the right side of the vehicle are connected to a second chamber of the pressure regulator
44
. Such a construction results in flow through the throttled passage
62
that extends between the chambers
46
,
48
when the vehicle rolls or otherwise sways laterally. Such flow results from the differing movements of the dampers on the left side of the vehicle and the dampers on the right side of the vehicle. As working oil flows through the throttle passage
62
, the movement of the pistons is further damped by the restriction of the throttled passage. The arrangement illustrated in
FIG. 1
, however, results in little flow between the two chambers through the throttle passage
62
when the vehicle pitches, such as during rapid acceleration or deceleration.
With reference now to the arrangement illustrated in
FIG. 2
, the dampers
22
,
28
and the dampers
24
,
26
are interrelated and are connected to the chambers
46
,
48
, respectively. In other words, the vehicle supported by the suspension system
20
illustrated in
FIG. 2
features cross-related dampers (i.e., left front damper
22
and right rear damper
28
are connected to a single chamber while the right front damper
24
and the left rear damper
26
are connected to a second chamber). This cross-arrangement results in increased damping forces caused by flow through the throttle passage
62
when the vehicle is twisted such as occurs when accelerating or decelerating into a corner or out of a corner. In other words, when the pressure is increased at one corner of the vehicle relative to the other three corners, increased damping results from flow between one of the chambers
46
,
48
into the other of the chambers
46
,
48
of the pressure regulator
44
.
With reference now to
FIG. 3
, each of the dampers
22
,
24
,
26
,
28
is connected to its own chamber
46
,
64
,
66
,
48
, respectively. The adjacent chambers such as
46
,
64
, or
64
,
66
or
66
,
48
are directly interconnected by throttle passages. In this manner, when the vehicle rolls (i.e., rotates about a longitudinally extending axis) differential pressures result within the two chambers associated with the left side of the vehicle as compared to the two chambers associated with the right side of the vehicle. Accordingly, working oil flows through three throttle passages (
68
,
70
,
62
) to equalize the differentials in the oil pressure. Thus, the pressure regulator
44
provides increased damping force during rolling movement of the vehicle body. In addition, with the suspension system
20
illustrated in
FIG. 3
, when the vehicle body pitches (i.e., rotates about a transversely extending axis) working oil passes between the chambers
46
,
64
and
66
,
48
through the throttle passages
68
and
62
. This results in the pressure regulator
44
increasing the avai
Knobbe Martens Olson & Bear LLP
Lavinder Jack
Nguyen Xuan Lan
LandOfFree
Vehicle suspension system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vehicle suspension system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle suspension system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3295514