PLATE-FORME ELEVATRICE AUTOPROPULSEE ET SURBAISSEE POUR TRAVAUX EN HAUTEUR

VEHICULAR LOW PROFILE SELF PROPELLED AERIAL WORK PLATFORM

Abrégé anglais

A VEHICULAR LOW PROFILE SELF PROPELLED
AERIAL WORK PLATFORM
Abstract
A vehicular low profile self propelled aerial work
platform assembly having a turntable positioned in a
horizontal plane in close proximity to the axles of the
vehicle. A parallelogram linkage is provided between a
superstructure support frame carried by the turntable and a
riser frame assembly to which one end of a telescopic boom
assembly is pivotally connected, the aerial work platform
being mounted on the outermost end of the telescopic boom
assembly. A counterweight is detachably connected to the
support frame and is formed with a trough aligned with a
similar trough provided in the support frame, the
parallelogram linkage includes a pair of tubular arms
which extend through the troughs when the work platform is
in the lowermost position. When in the lowermost position,
the height of the pivotal connection of the telescopic boom
assembly to the riser frame assembly is approximately eight
feet allowing the assembly to be employed in warehouses and
manufacturing plants having low and narrow doorways and
aisles. The support frame and parallelogram linkage are
symmetrical with respect to the centerline of the machine
to thereby distribute stresses equally through the machine.
When in the elevated position, the superstructure support
frame, parallelogram linkage, and counterweight are
positioned within the wheelbase of the vehicle to thereby
provide a zero tailswing.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A vehicular low profile self propelled aerial work
platform comprising a vehicle chassis, a turntable mounted on
said vehicle chassis and positioned in a horizontal plane in
close proximity to the axles of the vehicle, a superstructure
support frame mounted on said turntable, said superstructure
support frame including a pair of closely spaced side walls, a
pair of substantially parallel arms extending into the space
between said side walls, each arm having one end pivotally
connected to said side walls, a riser frame assembly, the
opposite end of each arm being pivotally connected to said
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 said first lift cylinder being
operably connected to one of said arms, a telescopic boom
assembly and associated work platform pivotally connected to
said riser assembly, a second lift cylinder operatively
connected between said riser frame assembly and said telescopic
boom assembly for luffing said boom assembly, the
superstructure side walls, parallel arms and riser frame
assembly providing a parallelogram linkage assembly, whereby
upon actuation of said 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 said side walls, a
trough formed in said counterweight, said trough being aligned
with the space between said 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.
2. A vehicular low profile self propelled aerial work
platform according to Claim 1, wherein the superstructure
support frame, parallel arms, riser frame assembly and tele-

scopic boom assembly are constructed and arranged 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 arms and superstructure side
walls.
3. A vehicular low profile self propelled aerial work
platform according to Claim 1, wherein, when the machine is in
the elevated position, the riser frame assembly, parallel arms,
superstructure support frame and counterweight are all
positioned within the wheel base of the vehicle, to thereby
provide a zero tailswing.
4. A vehicular low profile self propelled aerial work
platform according to Claim 1, wherein the arms are of tubular
construction and are disposed substantially in a vertical plane
with respect to each other.
5. A vehicular low profile self propelled aerial work
platform according to Claim 4, wherein the first lift is
operatively connected to the upper arm.
6. A vehicular low profile self propelled aerial work
platform according to Claim 5, wherein portions of the top and
bottom walls of the lower arm are cut-away to provide openings
to accommodate the first lift cylinder during the railing and
lowering of the arms.
7. A vehicular low profile self propelled aerial work
platform according to Claim 4, wherein the pivotal connec-
tion of the arms to the side walls of the superstructure
support frame are vertically aligned and positioned beneath
said telescopic boom assembly when in the negative angle
position.
8. A vehicular low profile self propelled aerial work
platform according to Claim 7, wherein the parallel arms are
slightly inclined when in the lowered position to thereby be
positioned in a lifting mode as soon as the first lift cylinder
is actuated.
9. A vehicular low profile self propelled aerial work
platform according to Claim 1 wherein the arms and riser frame
assembly are constructed and arranged to provide an elevated
pivot connection for the telescopic boom assembly, whereby the

boom pivot connection extends approximately eight feet above
the ground when the riser frame assembly is lowered to move the
boom assembly to the negative angle position, and extends
approximately fifteen feet above the ground when the riser
frame assembly is moved to the elevated position.
10. A vehicular low profile self propelled aerial
work platform according to Claim 8, in which the parallel arms
and telescopic boom assembly are inclined in the same
direction toward the front of the vehicle when said telescopic
boom assembly is in the negative angle position.
11. A vehicular low profile self propelled aerial
work platform according to Claim 1, wherein said pair of
parallel arms, first lift cylinder, riser frame assembly,
second lift cylinder, and telescopic boom assembly are
symmetrically positioned in a common vertical plane.
12. A vehicular low profile self propelled aerial
work platform according to Claim 11, in which said telescopic
boom assembly, said second lift cylinder and said pair of
parallel arms are respectively positioned one above the other
when in the lowered position.
13. A vehicular low profile self propelled aerial
work platform according to Claim 7, in which said turntable
having a centerline of rotation on said vehicle chassis, and
the pivotal connections of the arms to the side walls of the
superstructure support frame being on the same side of the
turntable centerline of rotation as the work platform on the
end of the telescopic boom assembly.
14. A vehicular low profile self propelled aerial
work platform according to Claim 7, in which the pivotal
connection of the arms to said riser frame assembly are
vertically aligned, and the pivot connection of said
telescopic boom assembly to said riser assembly being
positioned above and vertically aligned with the pivotal
connections of the arms to said riser frame assembly.
15. A vehicular low profile self propelled aerial
work platform according to Claim 14, and said second lift
cylinder pivotally connected to said riser frame assembly at a
position between the pivotal connections of the arms and the

pivot connection of said telescopic boom assembly to said riser
assembly.
16. A vehicular low profile self propelled aerial
work platform according to Claim 1, wherein the pair of
substantially parallel arms are positioned in substantially
horizontal planes above and in close proximity to the plane of
said turntable, and said second lift cylinder positioned in a
substantially horizontal plane above and in close proximity to
the horizontal planes of said arms in the retracted position of
the machine with the telescopic boom assembly in a negative
angle position.
17. A vehicular low profile self propelled aerial
work platform according to Claim 16, and the pivotal
connection of the telescopic boom assembly to said riser frame
assembly positioned above the pivotal connection of said second
lift cylinder to said riser frame assembly, and in vertical
alignment with the pivotal connections of the arms to said
riser frame assembly.

18. A vehicular low profile self propelled
aerial work platform comprising a vehicle chassis, a
turntable mounted on said vehicle chassis, a superstructure
support frame mounted on said turntable, said
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
said side walls, a riser frame assembly, the opposite end
of each arm being pivotally connected to said riser
assembly, a first lift cylinder positioned in the space
between the side walls and having one end pivotally
connected to said superstructure support frame, the
opposite end of said first lift cylinder being operably
connected to one of said arms, a telescopic boom assembly
and associated work platform pivotally connected to said
riser assembly, said telescopic boom assembly and said pair
of parallel arms symmetrically positioned about a common
vertical plane, a second lift cylinder operatively
connected between said riser frame assembly and said
telescopic boom assembly for luffing said boom assembly,
the superstructure side walls, parallel arms and riser
frame assembly providing a parallelogram linkage assembly,
whereby upon actuation of said 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
said side walls, a trough extending through said
counterweight, said trough being aligned with the space
between said 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.
19. A vehicular low profile self propelled
aerial work platform according to claim 1 or 18, wherein
said pair of substantially parallel arms extend into the
space between said side walls.
20. A vehicular low profile self propelled
aerial work platform according to claim 1 or 18, wherein
said pair of substantially 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.
21. A vehicular low profile self propelled
aerial work platform according to claim 18, wherein the
superstructure support frame, parallel arms, riser frame
assembly and telescopic boom assembly are constructed and
arranged 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 arms
and superstructure side walls.
22. A vehicular low profile self propelled
aerial work platform according to claim 18, wherein, when
the machine is in the elevated position, the riser frame
11

assembly, parallel arms, superstructure support frame and
counterweight are all positioned within the wheel base of
the vehicle, to thereby provide a zero tailswing.
23. A vehicular low profile self propelled
aerial work platform according to claim 18, wherein the
arms are of tubular construction and are disposed
substantially in a vertical plane with respect to each
other.
24. A vehicular low profile self propelled
aerial work platform according to claim 23, wherein the
first lift is operatively connected to the upper arm.
25. A vehicular low profile self propelled
aerial work platform according to claim 24, wherein
portions of the top and bottom walls of the lower arm are
cut-away to provide openings to accommodate the first lift
cylinder during the raising and lowering of the arms.
26. A vehicular low profile self propelled
aerial work platform according to claim 23, wherein the
pivotal connection of the arms to the side walls of the
superstructure support frame are vertically aligned and
positioned beneath said telescopic boom assembly when in
the negative angle position.
27. A vehicular low profile self propelled
aerial work platform according to claim 26, wherein the
parallel arms are slightly inclined when in the lowered
position to thereby be positioned in a lifting mode as soon
as the first lift cylinder is actuated.
12

28. A vehicular low profile self propelled
aerial work platform according to claim 18, wherein the
arms and riser frame assembly are constructed and arranged
to provide an elevated pivot connection for the telescopic
boom assembly, whereby the boom pivot connection extends
approximately eight feet above the ground when the riser
frame assembly is lowered to move the boom assembly to the
negative angle position, and extends approximately fifteen
feet above the ground when the riser frame assembly is
moved to the elevated position.
29. A vehicular low profile self propelled
aerial work platform according to claim 27, in which the
parallel arms and telescopic boom assembly are inclined in
the same direction toward the front of the vehicle when
said telescopic boom assembly is in the negative angle
position.
30. A vehicular low profile self propelled
aerial work platform according to claim 18, wherein said
pair of parallel arms, first lift cylinder, riser frame
assembly, second lift cylinder, and telescopic boom
assembly are symmetrically positioned in a common vertical
plane.
31. A vehicular low profile self propelled
aerial work platform according to claim 30, in which said
telescopic boom assembly, said second lift cylinder and
said pair of parallel arms are respectively positioned one
above the other when in the lowered position.
32. A vehicular low profile self propelled
13

aerial work platform according to claim 26, in which said
turntable has a centerline of rotation on said vehicle
chassis, and the pivotal connections of the arms to the
side walls of the superstructure support frame being on the
same side of the turntable centerline of rotation as the
work platform on the end of the telescopic boom assembly.
33. A vehicular low profile self propelled
aerial work platform according to claim 26, in which the
pivotal connections of the arms to said riser frame assembly
are vertically aligned, and the pivot connection of said
telescopic boom assembly to said riser assembly being
positioned above and vertically aligned with the pivotal
connections of the arms to said riser frame assembly.
34. A vehicular low profile self propelled
aerial work platform according to claim 33, and said second
lift cylinder pivotally connected to said riser frame
assembly at a position between the pivotal connections of
the arms and the pivot connection of said telescopic boom
assembly to said riser assembly.
35. A vehicular low profile self propelled
aerial work platform according to claim 18, wherein the
pair of substantially parallel arms are positioned in
substantially horizontal planes above and in close
proximity to the plane of said turntable, and said second
lift cylinder positioned in a substantially horizontal
plane above and in close proximity to the horizontal planes
of said arms in the retracted position of the machine with
the telescopic boom assembly in a negative angle position.
14

36. A vehicular low profile self propelled
aerial work platform according to claim 35, and the pivotal
connection of the telescopic boom assembly to said riser
frame assembly positioned above the pivotal connection of
said second lift cylinder to said riser frame assembly, and
in vertical alignment with the pivotal connections of the
arms to said riser frame assembly.

Description

129Z957
-- 1 --
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
3b

~292957
2 --
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.

lZ9Z9S7
- 2a -
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

' lZgZ957
- 2b -
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
.~ '

~Z9Z957
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

:129Z9S7
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

12~Z95~
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.

Dessin représentatif