Land vehicles – Wheeled – Running gear
Reexamination Certificate
2001-01-12
2002-12-03
Dickson, Paul N. (Department: 3616)
Land vehicles
Wheeled
Running gear
C280S080100, C280S043000
Reexamination Certificate
active
06488297
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a suspension device of an industrial vehicle and, more particularly, to a suspension device for a reach type forklift.
FIG. 17
illustrates a suspension device for a reach type forklift, which is disclosed in Japanese Unexamined Patent Publication No. 8-164722.
FIG. 17
is rear view of a forklift. The suspension device suspends a rear wheel
183
and a caster
184
such that the rear wheel
183
and the caster
184
move vertically relative to the vehicle body. The rear wheel
183
functions as a driving wheel and a steered wheel.
A cab
180
is located at the rear right of the body. An operator stands in the cab
180
. A control panel
181
is located in the front of the cab
180
. A steering wheel
182
is located to the left of the cab
180
. The rear wheel
183
is steered in accordance with manipulation of the steering wheel
182
. The rear wheel
183
, or the driving wheel, is located to the left of the cab
180
. The caster
184
is located below a bottom plate
180
a
of the cab
180
.
The suspension device includes a parallel linkage
188
. The parallel linkage
188
includes a support link
191
, an upper link
192
, a lower link
193
and a caster link
194
. The support link
191
includes a horizontal support base
191
a
and an arm
191
b
, which extends downward from one end of the support base
191
. A drive unit
187
for supporting the driving wheel
183
is attached to the support base
191
a
. The drive unit
187
includes a drive motor
185
and a gear housing
186
. The gear housing
186
has gears for transmitting rotation of the drive motor
185
to the driving wheel
183
. The caster
184
is attached to the distal end of the caster link
194
.
One end of the upper link
192
is coupled to the vehicle body by a shaft
195
. The other end,of the upper link
192
is coupled to the support base
191
a
by a shaft
197
. One end of the lower link
193
is coupled to the lower end of the arm
191
b
by a shaft
198
. The other end of the lower link
193
is coupled to the vehicle body by a shaft
196
. The proximal end of the caster link
194
is coupled to the shaft
196
. The axes of the shafts
195
to
198
are the vertexes of an imaginary parallelogram.
The shafts
195
,
196
are fixed to the vehicle body. In other words, the shafts
195
,
196
are fulcrums of the linkage
188
. The parallel linkage
188
is moved about the shafts
195
,
196
in accordance with the load acting on the driving wheel
183
and the caster
184
. The shafts
195
,
196
function as fulcrums. As a result, the driving wheel
183
and the caster
184
are moved in opposite directions.
A lift mechanism (not shown) for carrying loads is located in the front portion of the vehicle body. A reach cylinder
110
is located at the lower part of the body in the center of the lateral direction. The reach cylinder
110
moves the lift mechanism forward and-rearward. The reach cylinder
110
extends in the longitudinal direction of the vehicle body and intersects the lower link
193
.
The cab
180
is preferably wide for permitting an operator to easily manipulate the forklift (width is the left-right dimension of FIG.
17
). However, in the forklift shown in
FIG. 17
, the arm
191
b
of the support link
191
is located to the right of the drive unit
187
. That is, the arm
191
b
is located between the drive unit
187
and the cab
180
. Accordingly, the width of the cab
180
is reduced by an amount corresponding the size of the arm
191
b.
The width of the vehicle may be increased to increase the width of the cab
180
. However, increasing the width of the vehicle hinders loading and unloading in small spaces.
The lower link
193
is located below the bottom plate
180
a
of the cab
180
. The reach cylinder
110
is located below the lower link
193
and is transverse to the lower link
193
. Therefore, a relatively large space is required below the bottom plate
180
a
for the lower link
193
and the reach cylinder
110
. To permit the lower link
193
move vertically, space for the lower link
193
to move must be provided. Accordingly, the bottom,plate
180
a
must be located at a relatively raised position.
However, raising the bottom plate
180
a
makes it harder for an operator to get on and off the vehicle. Operators frequently get on and off reach type forklifts. The bottom plate
180
a
, which is raised to a relatively high position, thus lowers efficiency and increases operator fatigue.
Japanese Unexamined Patent Publication No. 8-156544 discloses a suspension device that is similar to the device of FIG.
17
. The device of the publication No. 8-156544 does not include a parallel linkage. However, like the device of
FIG. 17
, elements that form the suspension are located between the cab and the drive unit. Therefore, the width of the cab is limited.
SUMMARY OF THE INVENTION
Accordingly, it an objective of the present invention to provide a suspension device that increases the width of the cab of a vehicle without increasing the width of the vehicle body of the vehicle.
Another objective of the present invention is to provide a suspension device that lowers the bottom plate of the cab.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a suspension device for an industrial vehicle is provided. The vehicle has a driving wheel and a coasting wheel, which are laterally spaced apart. The suspension device suspends the driving wheel and the coasting wheel relative to a vehicle body. A cab is located at a side of the vehicle body and above the coasting wheel. The suspension device includes a coasting wheel support, a drive unit, a drive unit support and a coupler. The coasting wheel support supports the coasting wheel such that the coasting wheel moves upward and downward relative to the vehicle body. The driving wheel is attached to the drive unit. The drive unit support supports the drive unit such that the drive unit moves upward and downward relative to the vehicle body. The coupler is located in the vehicle body. The drive unit support is coupled to the coupler such that the drive unit support moves relative to the vehicle body. The coupler is located at a position other than a position that is lateral of the drive unit.
The present invention provides another suspension device for an industrial vehicle. The vehicle has a driving wheel and a coasting wheel, which are laterally spaced apart. The suspension device suspends the driving wheel and the coasting wheel relative to a vehicle body. The suspension device includes a coasting wheel support, a drive unit, a drive unit support and an interlock mechanism. The coasting wheel support supports the coasting wheel such that the coasting wheel moves upward and downward relative to the vehicle body. The driving wheel is attached to the drive unit. The drive unit support supports the drive unit such that the drive unit moves upward and downward relative to the vehicle body. The interlock mechanism interlocks the drive unit support with the coasting wheel support such that the driving wheel and the coasting wheel move in opposite directions. The interlock mechanism includes a rotatable shaft that extends in the lateral direction of the vehicle body. Load acting on the driving wheel and load acting on the coasting wheel are applied to the shaft as opposing torsional forces. The shaft rotates such that the torsion applied to the shaft by the driving wheel and the torsion applied to the shaft by the coasting wheel are balanced, and the driving wheel and the coasting wheel move in opposite directions.
The present invention further provides another suspension device for an industrial vehicle. The vehicle has a driving wheel and a coasting wheel, which are laterally spaced apart. The suspension device suspends the driving wheel and the coasting wheel relative to a vehicle body. The vehicle includes a cab located at a side of the vehicle body and above the coasting wheel. The vehicle also includes a carrier for carr
Dickson Paul N.
Fleming Faye M.
Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
Morgan & Finnegan , LLP
LandOfFree
Suspension device of industrial vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Suspension device of industrial vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suspension device of industrial vehicle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2991050