Field of the Invention
The present invention relates to a method for dampening the shocks with an
apparatus having automatic ride control system.
More particularly the present invention relates to an apparatus with a hydraulic
system which have the improved ride control system.
Still more particularly, this present invention also relates to an apparatus having
a dampening the shocks in a construction industry vehicle with front end loader.
Background of the invention
It is well known in the art that when a machine, such as a wheel loader, backhoe
loader, with a loaded bucket is driven there is always the possibility that the
machine will lope or bounce due to the weight of the loaded bucket reacting to \ ,
the machine encountering rough terrain or other obstacles. In order to help
reduce or eliminate this lope or bounce it is know to use accumulators that are
sel.ectively connected to the lift actuators. With the accumulator connected to
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the loaded end of the lift actuator pressure fluctuations in the actuators is
absorbed thus offsetting changing forces acting on the tires of the machine. It is
the changing forces acting on the tires of the machine that produces the lope or
bounce. In order to maintain a pre-charge in the accumulator equal to the
pressure in the loaded end of the actuators, it is known to connect the
accumulator, during normal use, to the loaded end of the lift actuators by
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connecting a conduit there between-;The conduit normally has a valve, having
an orifice, that is selectable moved to dispose the orifice within the conduit
when the machine is not operating in the ride control mode. It has been found
that during some situations that the pressure in the accumulator may not be
equal to the pressure in the loaded end of the lift actuator when the ride control
is activated. The pressure not being equalized could allow the load to "drop"
slightly or "jump" thus adding to the problem of machine bounce or subjecting
the machine to a "jolt" Furthermore, it has been found that in previous systems,
the ride control is always functional, once activated, even though operating
conditions would be better if the ride control were turned off.
Various types of off-road or construction vehicles are used to perform functions
such as leveling, digging, material handling, trenching, plowing, etc. These
operations are typically accomplished with the use of a hydraulically operated
bucket, backhoe or other implement. These implements include a plurality of
linkages translationally supported and rotationally supported, and are moved
relative to the supports by hydraulic cylinders or motors. As a result of the type
of work these machines are used to perform (i.e. job site work) these machines
are often required to travel on roads between job sites. Accordingly, it is
important that the vehicle travel at reasonably high speeds. However, due to the
overhanging of the implements supported on the vehicle, vehicle bouncing,
pitching or oscillation occurs at speeds satisfactory for road travel.
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The known US Patent No.5733095 states that in machines having a bucket that
is capable of carrying a load of material, it is well know that when the machine
is traveling over rough terrain or encounters other obstacles the machine may
bounce or the operator may be subjected to a jolt due to a change in force acting
on the lift actuator. Accumulators have been connected to the loaded end of the
lift actuator to cushion or dampen the sudden changes in the forces. When the
machine is used without the accumulator connected to the lift actuator a
pressure balancing valve mechanism is provided to maintain a pre-charge in the
accumulator greater than or equal to the pressure in the head end of the lift
actuator when the ride control come.s on. In order to ensure that the pressure in ,
the accumulator is always equal to the pressure in the head end of the lift
actuator when ride control comes on, the accumulator is selectively connected
to the implement pump or the reservoir. When in a manual mode the ride
control is turned off when a tilt lever is moved to tilt the bucket, and when in a
automatic mode the ride control is turned off when the machine is being
operated below a predetermined ground speed.
The·known US Patent No. 5897287 desctibes··a control system for improving
the roadability of a wheeled excavator is disclosed herein. The excavator is the
tY!Jeincluding an implement such as a bucket or backhoe which is moved
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relative to the excavator by hydraulic actuators. Hydraulic fluid is applied to the
actuators via electronic valves which are controlled by an electronic controller.
Based upon acceleration of the vehicle, the electronic controller controls the
electronic valve to maintain fluid pressure in the actuator or the acceleration
substantially constant. Additionally the controller can be configured to maintain
the average position of the implement generally constant. By controlling the
pressure in the hydraulic actuator, the undesirable bouncing or pitching of the
excavator can be reduced when the vehicle is traveling at road or loading
speeds.
The know Japan Patent No. 2000-309953 describes the suppressing of these
vibrations, a bottom pressure chamber of a boom cylinder and an accumulator
are brought into communication with each other during traveling to have
pressure fluctuations in the bottdm ~pressure chamber absorbed in the
accumulator, and during digging work with a bucket, on the other hand, the
communication with the accumulator is cut off to prevent the absorption of
digging force in the accumulator. As a conventional technique of this sort,
reference can be made to.
According to the known US Patent No. 5992146, a variable rate ride control
system adapted for use on a machine having a frame with a lift mechanism
operative through an actuator to raise a bucket relative to the frame, the actuator
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having first and second ports and operative to raise and lower the bucket in
response to pressurized fluid being selectively directed to and from the
respective ports thereof from a fluid circuit having a directional control valve
that is connected to a source of pressurized fluid and a reservoir, and an
accumulator arrangement connected to the first port of the actuator, the variable
rate ride control system comprising: a first valve mechanism operatively
disposed in a fluid conduit between the accumulator arrangement and the first
port of the actuator, the first valve mechanism has a spring biased end and a
pressure responsive end and is movable from a spring biased first position at
which communication is controllably permitted from the accumulator
arrangement to the first port of the actuator towards a second position at which
there is open communication there through; a flow restriction mechanism
disposed in the fluid conduit between the first valve mechanism and the first
port of the actuator;
a first signal conduit connected to the fluid conduit at a point between the flow
restriction mechanism and the first port of the actuator and to the pressure
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responsive end of the first valve mechanism; a second signal conduit connected
to the fluid conduit at a point between the flow restriction mechanism and the
first valve mechanism and the spring biased end of the first valve mechanism; a
pilot valve mechanism operatively disposed in the first signal conduit and
operative to selectively control fluid flow through the first signal conduit, the
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pilot valve mechanism is movable between a spring biased first position at
which the flow through the first signal conduit is blocked and a second position
at which the flow there through is open, the pilot valve mechanism is movable
to the second position in response to receipt of an external signal.
The other known invention which disclosed on US Patent No. 6357230, states
that a hydraulic ride control system'is disclosed and adapted to control the ride
of a machine having a load, The ride control includes an accumulator
arrangement that is selectively connected with the actuator that is carrying the
load to provide a cushion ride during traveling and to enable the pressure in the
accumulator arrangement to be maintained substantially the same as the
pressure in the actuator when raising:the;Joad and to permit the pressure in the
accumulator arrangement to be lowered to that of the pressure in the actuator in
the event the load is lessened. The ride control system also provides an
arrangement that permits the accumulator arrangement to be bled down
whenever the machine becomes disabled or when the machine is shut off.
According to the known US Patent no.2010024411, a hydraulic system for a
mobile machine having an implement is disclosed, The hydraulic system may
have a hydraulic actuator configured to'1l.10Vethe implement, a storage device
configured to store pressurized fluid, and a valve operable to fluidly
communicate the storage device with the hydraulic actuator. The hydraulic
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system may also have a sensor associated with the mobile machine to generate a
signal indicative of a speed of the mobile machine, and a controller, in
communication with the valve and the sensor. The controller may be configured
to compare the speed of the mobile machine to a set point and to determine an
amount of time elapsed while the speed of the mobile machine exceeds the set
point. The controller may further be configured to selectively operate the valve
to fluidly communicate the storage device with the actuator based on the
el~psed amount of time and the speed to cushion movement of the implement.
The other known European Patent No. 1657213 states that a hydraulic system
for a wheeled loader having a loader arm assembly, which is connected to the
wheeled loader at a first end and carries a working implement at a second end,
and which loader arm is movable between raised and lowered positions by
means of a hydraulic cylinder, wherein a hydraulic accumulator means is
connected to the hydraulic cylinder to provide a suspension arrangement for the
hydraulic cylinder. Each chamber of the hydraulic cylinder is connected to a
~~~ection valve means via conduits adapted to supply fluid under pressure to
ratse or lower the loader arm assembly. The hydraulic system is provided with a
number of valves for preventing any unintentional downward movement of the
lift arm assembly due to a sudden loss of pressure in the supply conduit or a
slow leak through the selection valve means.; The 'invention further relates to a
wheeled loader provided with such a hydraulic system.
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Another known US Patent No. 5473990 states that a ride vehicle for used in an
amusement attraction. The ride vehicle mounts a structure upon a hydraulicallyactuated
motion base, so that the passenger holding structure may be articulated
about one or more axes as the vehicle moves. Thus, this "simulator ride" carries
passengers through three-dimensional scenery and articulates the passenger
holding structure in synchronism with motions of the ride vehicle, the motions
of moving show sets, which are external to the vehicle, sound, projection and
other effects. The ride vehicle! is ,programmably-controlled, and derives
electrical power from a track mounted power bus to drive vehicle hydraulics,
which drive motion base actuation, steering and vehicle velocity. The hydraulic
control system uses an electric pump to charge a high-pressure accumulator
with hydraulic power from a 480-volt power supply, a manifold to regulate the
supply of hydraulic energy to motion base and steering actuators and a
hydraulic motor, and a low-pressure accumulator that aids in regenerative
braking. Using these elements, the computerized vehicle-control system
controls the hydraulically-actuated elements to provide synchronized motions of
the vehicle and passenger holding structure, and other special effects, in
accordance with a selected one of a plurality of ride programs.
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As is known well, the ride control system is used to dampen shocks due to
weight overhang of front bucket by absorbing the pressure shocks in an
accumulator.
In the known damping system, the shocks are absorbed in the accumulator after
manual switching 'ON' the valves to direct the oil path to accumulator during
travelling or the mechanism is based on speed sensing that means the Ride
Control System gets switched automatically 'ON' if the speed of vehicle exceeds
the normal working speed. The ride control system remains inactive below that
speed.
The main disadvantage of the above systems is that either the system is operator
dependent or it remains inactive at low speeds even if the vehicle is travelling.
The operator can still experience shocks if vehicle is moving at slow speeds and
travelling through rough terrains, or speed breakers.
It has therefore been long felt need to develop method for dampening the shocks
with an apparatus having automatic ride control system by switching logic
which not only avoids the disadvantages mentioned above but is cheaper and
more economical to make.
According to present invention an automatic system has been developed which
senses the movement of Loader Le,\e~~o 4e~lde when to electrically disconnect
I ~ ' ••, '.
the accumulator from the hydraulic circuit to make the ride control system
inactive.
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None of these known patents, however alone or in combination, disclose the
present invention which is novel in nature.
Summary of the invention
A:cordingly an object of the present invention which relates a method for
dampening the shocks with an apparatus having automatic ride control system.
The present invention also relates to an apparatus with a hydraulic system which
have the improved ride control system. More particularly, this present invention
also relates to an apparatus having a dampening the shocks in a construction
industry vehicle with front end loader.
We shall now describe the invention with reference to accompanying drawings
which are given by way of illustration but does not restrict the scope of present
invention.
Brief description of the accompanying drawings
Fig 1 and 2 shows the working of the ,ride control system;
Fig 3 shows the arrangement of loader lever,
Fig 4 shows switches off the solenoids,
Detailed description of the invention with accompanying drawings
According to the present invention there is provided method for dampening the
shocks with an apparatus having automatic ride control system by switching
logic comprises the ride control system solenoids, Sl and S2, are switched ON,
the piston end of the lift ram gets. connected to the accumulator through the
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spool connected to solenoid S1 and the rod end of the lift ram gets connected to
the tank through the spool connected to solenoid S2 facilitating absorption of
shocks inside the accumulator the oil present in the piston end is free to move
the accumulator membrane up and down in the absence of pressure from the rod
end, the solenoids are switched off, the accumulator and tank line are cut-off
from the system and the ride control system stops working.
The ride control system remain inactive during normal working applications
such as loading and dozing.
The switching of the ride control system can be achieved based on speed or
manually.
An automatic method switches 'ON' the ride control system whenever required
without any human intervention at all speeds and the system uses actuators
present in the loader lever to sense when it is being operated
Accordingly to the present invention there is provided there are many possible
embodiments of this invention. The drawings and description below describe in
detail a preferred embodiment of the invention. It should be understood that the
present disclosure is to be considered of the present invention.
There are many possible embodiments of this invention. The drawings and
description below describe in detail a preferred embodiment of the invention. It
should be understood that the present disclosure is to be considered of the
present invention.
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The principal object of the invention is to provide a method for dampening the
shocks with an apparatus having automatic ride control system.
The other embodiment of the invention is to provide an apparatus with a
hydraulic system have the improved ride contro.! system.
The other embodiment of the invention is to provide an apparatus having a
dampening the shocks in a construction industry vehicle with front end loader.
The other embodiment of the invention is that the loader lever is moving with
respect to the machine chassis, is can be determined that loader of the machine
is being operated and the ride control accumulator needs to be disconnected
from the hydraulic circuit.
The advantages and novel features 9f the invention will become more apparent
from the following detailed description when taken in conjugation with
accompanying drawings and these drawings are illustrative in explaining the
constructional details of the apparatus of the invention. Such drawings are
shown in four sheets.
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The above diagram shows the working of the ride control system. When the ride
control system solenoids, Sl and S2, are switched ON, the piston end of the lift
ram gets connected to the accumulator through the spool connected to solenoid
S1 and the rod end of the lift ram gets connected to the tank through the spool
connected to solenoid S2 as shown in the diagram. These connections facilitate
absorption of shocks inside the accumulator as the oil present in the piston end
is free to move the accumulator membrane up and down in the absence of
pressure from the rod end. When the solenoids are switched off, the
accumulator and tank line are cut-off from the system and the Ride Control
System stops working.
In the current invention it is important that the Ride Control System remain
inactive during normal working applications such as loading and dozing. The
switching of the Ride Control System can be achieved by many means, for
example, based on speed or manually.
Tltis draft proposes an automatic method which switches 'ON' the Ride Control
System whenever required without any human intervention at all speeds. This
system uses actuators present in the loader lever to sense when it is being
operated (Fig 1 and 2).
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The electrical circuit diagram shown above switches OFF the solenoids present
in the ride control system to disable it so that the hydraulic operations of the
machine can occur properly ( Fig 4).
From the foregoing, it will be observed that numerous modifications and
variations can be effected without departing from the true spirit and scope of the
novel concept of the present control system. It will be appreciated that the
present disclosure is intended as an exemplification of the control system, and is
not intended to limit the control system to the specific embodiment illustrated.
The disclosure is intended to cover by the appended claims all such
modifications as fall within the scope of the claims.
In addition to the above claims, it is, added and further claimed that the method
for dampening the shocks with an apparatus having automatic ride control
system by switching logic is original.

WE CLAIM:
1. Method for dampening the shOG~kwsith an apparatus having automatic ride
control system by switching logic comprises the ride control system solenoids,
Sl and S2, are switched ON, the piston end of the lift ram gets connected to the
accumulator through the spool connected to solenoid S1 and the rod end of the
lift ram gets connected to the tank through the spool connected to solenoid S2
facilitating absorption of shocks inside the accumulator the oil present in the
piston end is free to move the accumulator membrane up and down in the
absence of pressure from the rod end, the solenoids are switched off, the
accumulator and tank line are cut-off from the system and the ride control
system stops working.
2. Method for dampening the shocks with an apparatus having automatic
ride control system by switching logic as claimed in claim 1, wherein the ride
control system remain inactive during normal working applications such as
loading and dozing.
3. Method for dampening the shocks with an apparatus having automatic ride
control system by switching logic as claimed in anyone of claims 1 and 2,
wherein the switching of the ride control system can be achieved based on speed
or manually.
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4. Method for dampening the shocks with an apparatus having automatic ride
control system by switching logic as claimed in anyone of claims 1,2 and 3
wherein an automatic method switches 'ON' the ride control system whenever
required without any human intervention at all speeds and the system uses
actuators present in the loader lever to sense when it is being operated.