Note: Descriptions are shown in the official language in which they were submitted.
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A VEHICULAR LOW PROFILE SELF PROPELLED
AERIAL WORK PLATFORM
Backqround of the Invention
Various vehicular self propelled aerial work
platforms have been proposed wherein a pedestal or housing
is mounted on a turntable carried by a vehicle. A boom
assembly, having a work platform mounted on its outer end,
is either pivotally connected directly to the pedestal or
through suitable linkage. While these known mobile aerial
work platforms have been generally satisfactory for their
intended purposes, they have been characterized by their
size and reach capabilities thereby precluding their use in
relatively small work areas, such as, in warehouses and
manufacturing plants having low and narrow doorways and
narrow aisles, but requiring high working heights.
After considerable research and experimentation,
the vehicular self propelled work platform of the present
invention has been devised having a low profile and a
narrow width so that it can be maneuvered through low and
: narrow doorways and aisles in warehouses and manufacturing
plants.
The vehicular low profile self propelled aerial
work platform in accordance with one embodiment of the
present invention comprises a vehicle chassis, a turntable
- mounted on the vehicle chassis and positioned in a
: 30 horizontal plane in close proximity to the axles of the
vehicle, a superstructure support frame mounted on the
turntable, the superstructure support frame including a
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pair of closely spaced side walls, a pair of substantially
parallel arms extending into the space between the side
walls, each arm having one end pivotally connected to the
side walls, a riser frame assembly, the opposite end of
each arm being pivotally connected to the riser assembly,
a first lift cylinder positioned in the space between the
side walls and having one end pivotally connected thereto,
the opposite end of the first lift cylinder being operably
connected to one of the arms, a telescopic boom assembly
and associated work platform pivotally connected to the
riser assembly, a second lift cylinder operatively
connected between the riser frame assembly and the
telescopic boom assembly for luffing the boom assembly, the
superstructure side walls, parallel arms and riser frame
assembly providing a parallelogram linkage assembly,
whereby upon actuation of the fir6t lift cylinder the
parallel arms and riser frame assembly are moved in a
vertical plane, a counterweight connected to one end of the
superstructure support frame and extending transversely to
the side walls, a trough formed in the counterweight, the
trough being aligned with the space between the side walls,
whereby the parallel arms extend between the superstructure
side walls and through the counterweight trough when the
first and second lift cylinders are retracted to move the
riser frame assembly and telescopic boom assembly to the
lowermost position wherein the boom assembly is lowered to
a negative angle, whereby the vehicle and associate boom
assembly can be easily maneuvered through low and narrow
doorways and aisles in warehouses and manufacturing plants.
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In a particularly preferred form, the support
frame, tubular arms, riser frame assembly and pivotal
connection of the telescopic boom to the riser frame
assembly are constructed and arranged to be symmetrical
with respect to the centerline of the machine whereby load
stresses are equally distributed from the telescopic boom
to the riser assembly through the tubular arms
superstructure side walls and turntable to the chassis.
When in the elevated position, the riser frame assembly,
tubular arms, superstructure support frame and
counterweight are positioned within the wheelbase of the
vehicle, to thereby provide a zero tailswing; that is, no
component extends beyond the wheels of the vehicle during
the sluing of the superstructure and the telescopic boom
assembly.
In accordance with another embodiment of the
present invention there is provided a vehicular low profile
self propelled aerial work platform comprising a vehicle
chassis, a turntable mounted on the vehicle chassis, a
superstructure support frame mounted on the turntable, the
superstructure support frame including a pair of closely
spaced side walls with a space therebetween, a pair of
substantially parallel arms, each arm having one end
extending into the space between and pivotally connected to
the side walls, a riser frame assembly, the opposite end of
each arm being pivotally connected to the riser assembly,
a first lift cylinder positioned in the space between the
side walls and having one end pivotally connected to the
superstructure support frame, the
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opposite end of the first lift cylinder being operably
connected to one of the arms, a telescopic boom assembly
and associated work platform pivotally connected to the
riser assembly, the telescopic boom assembly and the pair
of parallel arms symmetrically positioned about a common
vertical plane, a second lift cylinder operatively
connected between the riser frame assembly and the
telescopic boom assembly for luffing the boom assembly, the
superstructure side walls, parallel arms and riser frame
assembly providing a parallelogram linkage assembly,
whereby upon actuation of the first lift cylinder the
parallel arms and riser frame assembly are moved in a
vertical plane, a counterweight connected to one end of the
superstructure support frame and extending transversely to
the side walls, a trough extending through the
counterweight, the trough being aligned with the space
between the side walls, whereby at least one of the
parallel arms extends between the superstructure side walls
and through the counterweight trough when the first and
second lift cylinders are retracted to move the riser frame
assembly and telescopic boom assembly to the lowermost
position wherein the boom assembly is lowered to a negative
angle, whereby the vehicle and associate boom assembly can
be easily maneuvered through low and narrow doorways and
aisles in warehouses and manufacturing plants.
Brief Description of the Drawinas
Figure 1 is an elevational view of the vehicular
low profile self propelled aerial work platform of the
present invention showing the work platform in different
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working positions:
Figure 2 is a side elevational view of the
vehicle of the present invention showing the telescopic
boom assembly and associated work platform lowered to a
negative angle to provide access to the platform;
Figure 3 is a fragmentary side elevational view
showing the telescopic boom assembly moved to a raised
position relative to the vehicle;
Figure 4 is a fragmentary rear elevational view
taken substantially along line 4-4 of Figure 3; and
Figure 5 is a top plan view, partly in section,
taken substantially along line 5-5 of Figure 3.
~e~cription o~ t~e ~e~ lme~9l~ 1
Referring to the drawings and more particularly
to Figure 1, the vehicular low profile self propelled
aerial work platform of the present invention comprises a
superstructure support frame 1, having a counterweight 2,
mounted on a turntable 3 carried by a vehicle chassis 4.
A pair of substantially parallel tubular arms 5, 6 are each
pivotally connected at one end to the support frame as at
7 and 8, and at the opposite end to a riser frame assembly
9, as at 10 and 11. A telescopic boom assembly 12, having
a work platform 13 mounted on its outermost end, is
pivotally connected to the
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riser frame assembly as at 14. A lower lift cylinder 15 is
connected between the support frame 1 and the tubular arm 5 as
at 16 and 17, respectively, where-by the tubular arms 5 and 6
and riser frame 9 may be raised and lowered with respect to the
vehicle. A boom lift cylinder 18 is similarly connected
between the riser frame assembly as at 19 and the base section
of the telescopic boom assembly 12 as at 20, whereby the
telescopic boom assembly can be raised and lowered with respect
to the riser frame assembly 9, as shown in Figures 1, 2 and 3.
The details of the construction of the machine of the
present invention are illustrated in Figures 3, 4 and 5
wherein it will be seen that, to obtain the low profile
feature, the turntable 3 is positioned in a horizontal plane in
close proximity to the plane of the vehicle axles 21. The
superstructure support frame 1 comprises a pair of closely
spaced side wall.s 22, 23 secured to the turntable 3 and having
a ~ront end wall 24 and a pair of outwardly extending
transverse rear wall8 25 and 26. The detachable counterweight
2 is hooked as at 27 and 28 to the rear walls 25 and 26 and
bolted in place as at 29 and 30. The counterweight 2 is also
provided with lift pins 31 whereby a crane can lift the weight
for connecting it to the superstructure support frame.
As will be seen in Figure 5, the parallel arms 5 and 6
are of tubular or box construction in cross section and are
positioned in the space between the superstructure side walls
22 and 23, the pivotal connections 7 and 8 being vertically
aligned as shown in Figure 3. The space between the side walls
22 and 23 provides a trough 32 aligned with the centerline of
the vehicle chassis 4 and aligned with a similar trough 33
provided in the counterweight 2. By this c~nstruction and
arrangement the parallel arms 5 and 6 are aligned with the
centerline of the vehicle chassis and are received within the
troughs when the machine is lowered, as shown in Figure 2.
This arrangement also contributes to the low profile feature of
the machine, which has a height of approximately eight and a
half feet when positioned as shown in Figure 2. Machines with
lower maximum work platform heights will have a lower overall
height. While in the lowered position, as shown in Figure 2,
the parallel arms 5 and 6 are slightly inclined in a direction
toward the rear of the vehicle, although they are in
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substantially horizontal planes, and thus are initially
oriented or positioned to move in a lifting mode as soon as the
lift cylinder 15 is actuated as shown in Figure 3.
Since the arms 5 and 6 are of tubular construction, as
S will be seen in Figure 4, a portion of the top and bottom
walls of lower arm 6 are cut-away to form openings 34 and 35,
respectively, to accommodate the lift cylinder 15 and
associated piston rod during the raising and lowering of the
arms.
Referring to Figure 4, the riser frame assembly 9 is
configured as a channel member having a pair of spaced,
parallel side walls 36 and 37 interconnected by a web member
38. Reinforcing plates 39 and 40 are provided on the side
walls 36 and 37 at the pivotal connections 10 and 11 of the
arms 5 and 6. As will be shown in Figure 1, by the
construction and arran~ement of the lift arms 5 and 6 and riser
frame a~sembl~ 9, the telescopic boom as.sembly 12 is provided
with an elevate~ pivot connection 14, on the order of fifteen
feet above the ground, so that the boom 12 can extend over an
ob8truction 41 when the boom is horizontally oriented. This
type of machine is sometimes referred to as an up and over
machine. The riser frame assembly 9 always remains vertically
oriented in all positions of orientation of the machine. ~he
elevated pivot connection 14 also allows for the telescopic
boom assembly 12 and associated work platform 13 to be luffed
and extended to a position shown in phantom in Figure l,
wherein the work platform 13 extends approximately sixty feet
above the ground.
To complete the description of the vehicular, low
profile, self propelled aerial work platform of the present
invention, the telescopic boom assembly comprises a base
section 42 and a telescopic boom section 43, the base section
containing a fluid cylinder 44 fixed to the inner end of the
base section as at 45 and having a piston rod 46 extending into
the telescopic section 43 and fixed thereto as at 47. A master
cylinder 48 is connected between the riser frame assembly 9 and
the inner end of the base section 12, the master cylinder 48
being in fluid communication with a slave cylinder 49 mounted
on the outer end of the telescopic boom section 43 and
connected to the work platform 13 whereby the work platform 13
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is maintained in a horizontal position during the luffing of
the telescopic boom assembly 12, as well known in the art. The
base boom section 42 also contains a carrier track assembly 50
for supporting various power cables and hoses extending
through the telescopic boom assembly to the conventional
controls mounted on the work platform 13, whereby the worker on
the platform can control the maneuvering of the vehicle as well
as the sluing and luffing of the telescopic boom assembly.
The structure is completely symmetrical since the
telescopic boom assembly 12, boom lift cylinder 18, the pair of
parallel arms 5 and 6 and the lower lift cylinder 15 are all
positioned in the same vertical plane aligned with the
centerline of rotation of turntable 3, and aligned with the
centerline of the vehicle chassis in the lowered position of
the machine, so that a load on the work platform 13 and the
weight of machine components do not transmit any torque to the
turntable, a4 is the case in mo8t prior art machines of this
same general type. The geometry of the positioning of the
various structlJral elements in closely adjacent substantially
horizontal planes relative to each other, and the vertical
alignment of the pivot connections of the parallel arms 5 and 6
to the support frame, and the vertical alignment of the pivot
connections of the parallel arms to the riser frame assembly 9,
and vertical alignment with the pivot connec-tion of the
telescopic boom to the riser frame assembly are important
aspects of the invention which provide the low profile
capabilities of the machine in its retracted travel position.
The terms and expressions which have been employed
herein are used as terms of description and not of limitation,
and there is no intention, in the use of such terms and
expressions, of excluding any equivalents of the features shown
and described or portions thereof but it is recognized that
various modifications are possible within the scope of the
invention claimed.
