Note: Descriptions are shown in the official language in which they were submitted.
CA 02627562 2008-04-21
PORTABLE AERIAL PLATFORM
FIELD OF THE IIWENTION
The present invention relates to a retractable aerial platform mountable on a
vehicle for
supporting a person or materials.
BACKGROUND OF THE INVENTION
In the oil and construction industries, it is often necessary to provide
aerial platforms to
elevate worlcmen above ground level in outdoor and indoor locations to permit
repairs to
elevated structures or to lift materials to elevated sites. Safety measures
and fall protection are
required for such oilfield site servicing and construction environments.
Several prior art aerial platforms exist; hawever, they tend to be extremely
heavy, bulky
and complex, making the aerial platforms difficult to operate, store, lift,
transport, assemble or
disassemble. Prior art aerial platforms often include inadequate bracing or
guardrails, unsafe
access or other structural flaws, often contrary to occupational health and
safety regulatory
requirements. What is needed is an improved aerial platform which mitigates
the disadvantages
of the prior art.
SUNIlVIARY OF THE INVENTION
The present invention is directed to a retractable aerial platform. In one
aspect of the
invention, the invention comprises a vertically and horizontally-controlled,
retractable aerial
platform mountable on a vehicle having a substantially horizontal bed with a
longitudinal axis,
the aerial platform comprising:
a) a base mounted on the bed;
b) at least one support arm having a first end and a second end, the first end
being
attached to the base;
CA 02627562 2008-04-21
c) a first support member pivotally attached to the second end of the at least
one
support arm, the first support member being movable between a closed position
wherein it rests in a plane that is substantially parallel to the bed, and an
open
position wherein it rests in a substantially vertical orientation in a plane
that is
perpendicular to the bed;
d) a second support member pivotally attached to the first support member, the
second support member being movable between a closed position wherein it rests
in a'plane that is substantially parallel to the first support member, and an
open
position wherein it rests in a substantially horizontal plane perpendicular to
the
first support member when in its open vertical position, and perpendicular to
the
longitudinal axis of the bed, wherein the second support member is movable
along the length of the first support member;
e) a platform mounted on the second support member, wherein the platform is
movable along the length of the second support member; and
f) actuation means for moving the first and second support members between the
open and closed positions, for moving the second support member along the
length of the first support member and for moving the platform along the
length
of the second support member.
In one embodiment, the platform fiu-ther comprises a collapsible frame mounted
on the
platform moveable between a first collapsed position wherein the frame is
substantially parallel
to the platform and a second erect upright position. In one embodiment, the
base comprises first
and second spaced leg members which extend downwardly from the base for
attachment to the
bed. In one embodiment, the first support member comprises a frame having
first and second
spaced parallel side members reinforced by crossbeams, and a lifting member
moveable
longitudinally between the first and second side members, the second support
member being
pivotally attached to the lifting member.
In one embodiment, the first support member further comprises a plurality of
spaced
parallel rollers arranged in pairs within the first and second side members
for lowering or raising
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CA 02627562 2008-04-21
the lifting member longitudinally between the first and second side members.
In one
embodiment, the first support member further comprises a chain-based system
for lowering or
raising the lifting member longitudinally between the first and second side
members.
In one embodiment, the collapsible frame comprises side rails positioned on
the edges of
the platform and extending vertically, and hand rails and crossbeams extending
horizontally to
connect the opposite side rails.
In one embodiment, the actuation means is selected from a hydraulic system, an
electric
system, or a hydraulic and electric based system. In one embodiment, the
actuation means for
moving the first and second support members between open and closed positions
comprises a
hydraulic cylinder having a piston rod, the hydraulic cylinder being pivotally
mounted to the
base and the piston rod being pivotally mounted to the first support member.
In one
embodiment, the actuation means for moving the platform along the length of
the second support
member comprises an electric actuator driven by an electric motor to extend or
retract the
platform horizontally along the second support member away from or towards the
first support
member. In one embodiment, the electric actuator comprises a worm gear.
In one embodiment, the actuation means for moving the second support member
along
the length of the first support member comprises an electric motor positioned
on the first support
member and associated with gears to drive a cable-driven system to enable
vertical upward and
downward movement of the lifting member. In one embodiment, the cable-driven
system
comprises upper and lower roller bushings at the ends of the first support
member, a spring
within the upper end of the lifting member, cable mmni.ng from the gears to
the lower roller
bushing and connected to the spring, and cable running from the gears to the
upper roller bushing
and connected to the lower end of the lifting member.
In another embodiment, the platform further comprises a control unit selected
from a
portable hand control unit, a vehicle positioned control unit, or a ground
level control unit.
In a further embodiment, the platform is grated or comprises a metal floor
grille or lattice.
In a further embodiment, the platform furrher comprises two opposing end
members and two
opposing lateral members attached to the platform and frame to form an
enclosure. In yet a
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CA 02627562 2008-04-21
further embodiment, the support arm is branched forming a"v" shape, the apex
of the v being
pivotally attached to the first support member.
In one aspect of the invention, it comprises a retractable aerial platform
mountable on a
substantially horizontal surface, the aerial platform comprising:
a) a base mounted on the horizontal surface;
b) at least one support arm having a first end and a second end, the first end
being
attached to the base;
c) a first support member pivotally attached to the second end of the at least
one
support arm, the first support member being movable between a closed position
wherein it rests in a plane that is substantially parallel to the horizontal
surface,
and an open position wherein it rests in a substantially vertical orientation
in a
plane that is perpendicular to the horizontal surface;
d) a second support member pivotally attached to the first support member, the
second support member being movable between a closed position wherein it rests
in a plane that is substantially parallel to the first support member, and an
open
position wherein it rests in a substantially horizontal plane perpendicular to
the
first support member in its open vertical position, wherein the second support
member is movable along the length of the first support member;
e) a platform mounted on the second support member, wherein the platform is
movable along the length of the second support member; and
f) actuation means for moving the first and second support members between the
open and closed positions, for moving the second support member along the
length of the first support member and for moving the platform along the
length
of the second support member.
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CA 02627562 2008-04-21
BRIEF DESCRIPTION OF THE DRAWYNGS
The invention will now be described by way of an exemplary embodiment with
reference
to the accompanying simplified, diagrammatic, not-to-scale drawings.
Figure 1 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention in the closed position when installed on
the bed of a
vehicle.
Figure 2 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention.
Figure 3 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention.
Figure 4 is a diagrammatic representation of a side view of a retractable
aerial platform of
one embodiment of the present invention.
Figure 5 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention.
Figure 6 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention.
Figure 7 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention.
Figure 8 is a diagrammatic representation of a top view of a retractable
aerial platform of
one embodiment of the present invention.
Figure 8a is an enlarged view of a partially cut away section of a retractable
aerial
platform of Figure 8, showing the detail of an attachment means.
Figure 8b is an enlarged view of a partially cut away section of a retractable
platform of
Figure 8, showing the detail of an attachment means.
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CA 02627562 2008-04-21
Figure 9 is a diagrammatic representation of a retractable aerial platform of
one
embodiment of the present invention.
Figure 10 is a diagrammatic representation of one embodiment of the present
invention
mounted to horizontal surface.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides for a retractable aerial platform. When
describing the
present invention, all terms not defined herein have their common art-
recognized meanings. To
the extent that the following description is of a specific embodiment or a
particular use of the
invention, it is intended to be illustrative only, and not limiting of the
claimed invention. The
following description is intended to cover all alternatives, modifications and
equivalents that are
included in the spirit and scope of the invention, as defined in the appended
claims.
"Horizontal" means a plane that is substantially parallel to the plane of the
horizon.
"Vertical" means a plane that is perpendicular to the horizontal plane.
The invention will now be described having regard to the accompanying Figures.
The
retractable aerial platform (1) is shown generally in Figure 1 to include a
base (10), at least one
support arm (12), a first support member (14), a second support member (16), a
platform (18), a
frame (20), and actuation means (22). Figure 1 shows the retractable aerial
platform (1) mounted
onto the bed (2) of a commercial or other motor vehicle (3), for example, a
truck, a pick-up
truck, a half-ton truck, a three-quarter-ton truck, or a one-ton truck. In one
embodiment, the
vehicle (3) is a half-ton truck or a three-quarter-ton truck.
The base (10) is sized so as to be fully accommodated within the side walls of
the bed
(2), but with minimal intrusion to allow space for other equipment within the
bed (2). In one
embodiment, the base (10) takes up 30% of the bed (2), with 70% of the bed (2)
available for
other equipment. The base (10) comprises first and second spaced leg members
(24, 26) which
extend downwardly from the base (10) and are secured to the bed (2) and frame
(4) of the vehicle
(3) by suitable attachment means including, for example, brackets (28, 30) or
screws, to allow
the retractable platform (1) to be installed or released from the bed (2) and
frame (4) of the
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CA 02627562 2008-04-21
vehicle (3). It will be understood by those skilled in the art that if
desired, the retractable aerial
platform (1) can be permanently attached to the bed (2) by welding or other
known techniques if
the vehicle (3) is to be used regularly or solely in elevated working
environments. The base (10)
can be formed of any suitable material, although for strength and to withstand
cold and adverse
field conditions, the base (10) may be formed of aluminum or steel.
The support arm (12) has first and second ends (32, 34), of which the first
end (32) is
attached to the base (10) and the second end (34) is pivotally attached to the
first support
member (14). In one embodiment, there is at least one support arm (12). In one
embodiment,
there are two support arms (12), one on each side of the base (10), as shown
in Figure 8. In one
embodiment, the support arm (12) is branched and formed in the shape of a "V,"
with the ends
(32) of the "V" attached to the base (10) by welding, and the apex of the "V"
having a pivot (36)
formed thereon for attachment to the first support member (14). The support
arm (10) can be
formed of any suitable material including, for example, aluminum or steel. The
first support
member (14) is pivotally attached to the second end (34) of the support arm
(12), so as to be
movable between a closed position wherein it rests in a plane that is
substantially parallel to the
bed (2) (as shown in Figure 1), and an open position wherein it rests in a
substantially vertical
orientation in a plane that is perpendicular to the bed (2) (as shown in
Figures 2-7 and 9). The
first support member (14) comprises a frame (38) having first and second
spaced parallel side
members (40) which may be reinforced by crossbeams (42). In one embodiment,
the first and
second parallel side members (40) may be provided with cushioned bumpers along
their outer
lengths or full-length side rubber stoppers to cushion the first support
member (14) from other
components (i.e., preventing damage) as the retractable platform is moved into
the closed
position.
The first support member (14) includes a lifting member (44) which is moveable
longitudinally between the first and second side members (40) which remain
stationary during
the movement of the lifting member (44). In order to lower or raise the
lifting member (44), the
first support member (14) includes a plurality of spaced parallel rollers (46)
arranged in pairs
within the first and second side members (40). The first support member (14)
can be formed of
any suitable material including, for example, aluminum or steel. The rollers
(46) can be formed
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CA 02627562 2008-04-21
of any suitable material including, for example, metal or polymers such as,
for example,
neoprene. It will be appreciated by those skilled in the art that a chain-
based system could also
be used to lower or raise the lifting member (44).
The second support member (16) is pivotally attached to the lifting member
(44) of the
first support member (14), and is moveable between a closed position wherein
it rests in a plane
that is substantially parallel to the bed (2) (as shown in Figure 1), and an
open position wherein it
rests in a substantially horizontal plane parallel to the bed (2) and
perpendicular to the
longitudinal axis of the bed (2) (as shown in Figure 5) and perpendicular to
the first support
member (14) when in its open vertical plane. As the second support member (16)
is pivotally
attached by a pivot (48) to the lifting member (44), it is moveable along the
length of the first
support member (14), as shown in Figures 2 and 3 which illustrate its
transition between the
closed and open positions. The second support member (16) can be formed of any
suitable
material including, for example, aluminum or steel.
The platform (18) is mounted on the second support member (16) by suitable
attachment
means including, for example, a hinge or an axel bolt (48), as shown in
Figures 8a and 8b. The
platform (18) is moveable in two directions, namely horizontally back and
forth along the length
of the second support member (16) so as to extend outwardly from or retract
towards the first
support member (14), and vertically up or down due to attachment of the second
support member
(16) to the lifting member (44). In one embodiment, the platform (18) is
moveable three to five
feet horizontally and two to ten feet vertically. The platform (18) can be
formed of any suitable
material including, for example, aluminum, steel or wood. Workmen are
generally prohibited
from working on platforms covered with snow, ice or accumulated debris except
to remove the
hazards. In one embodiment, the platform (18) is grated or comprises a metal
floor grille or
lattice to provide a slip-resistant surface, improving tread grip and safety
during normal or
adverse conditions.
In one embodiment, a spring adjustment is included to control the descent of
the second
support member (16) from its closed position to its open position. The spring
adjustment is
dependent upon factors such as, for example, the combined platform weight and
the second
support member weight. In one embodiment, the spring adjustment ranges from
about 85-100
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CA 02627562 2008-04-21
degrees. Figures 8a and 8b illustrate the spring (50) through which the axel
bolt (48) extends to
attach the platform (18) to the second support member (16). As the second
support member (16)
descends into its open position, the spring (50) is gradually co`mpressed
allowing the second
support member (16) to descend in a controlled manner.
A frame (20) is mounted on the platform (18) by suitable attachment means
including, for
example, screws or bolts. The frame (20) is constructed from any suitable
material such as
aluminum or steel. The frame (20) includes side rails (52) positioned on the
edges of the
platform (18) and extending vertically. Hand rails (54) and crossbeams (56)
for barring a fall
extend horizontally to connect opposite side rails (52). In one embodiment,
two opposing end
members (58) and two opposing lateral members (60) are attached to the
platform (18) and frame
(20) to form an enclosure commonly referred to as a "toe board" in the art at
the base of the
platform (18), providing additional fall protection. In one embodiment, the
frame (20) is
collapsible into a closed position as shown in Figures 1-5, and erectable into
an upright position
as shown in Figures 6-9. Use of a collapsible frame (20) pre-mounted to the
platform (18)
affords convenience; however, it will be appreciated by those skilled in the
art that a non-
collapsible frame could be readily attached and released from the platform
(18).
The retractable aerial platform (1) includes actuation means (22) for driving
the
movement of the first and second support members (14, 16) between their open
and closed
positions, for moving the second support member along the length of the first
support member,
and for moving the platform (18) on the second support member (16). In one
embodiment, the
actuation means (22) comprises a combination hydraulic and electric based
system. In one
embodiment, the actuation means (22) comprises a 12V DC hydraulic and electric
based system.
In one embodiment, the actuation means comprises a hydraulic system. In one
embodiment, the
actuation means comprises an electric system.
The operation of hydraulic cylinders is commonly known to those skilled in the
art and
will not be discussed in detail. Briefly, a hydraulic pump, powered by an
appropriate power
source, drives oil to the hydraulic cylinder which converts the energy
transferred to the oil by the
pump to a mechanical output, namely the linear thrust of a piston rod. Where
power
requirements for the retractable platform (1) or any component thereof is
described, one skilled
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CA 02627562 2008-04-21
in the art will realize that any suitable power source may be used, including,
without limitation,
the vehicle's electrical system, rechargeable and non-rechargeable batteries,
self-contained power
units, or other appropriate sources.
In one embodiment, the actuation means for moving the first and second support
members (14,16) between their open and closed positions (22) comprises a
hydraulic cylinder
(62) having a piston rod (64). The hydraulic cylinder (62) is double-acting,
namely able to
control a load in two directions. The hydraulic cylinder (62) is pivotally
mounted at one end (66)
on a pivot (68) secured to the base (10) by suitable attachment means
including, for example, a
bracket (70). The piston rod (64) is pivotally mounted to the first support
member (14) to
provide sufficient output force to extend or retract the fiust and second
support members (14, 16)
between their open and closed positions.
In one embodiment, an electric actuator (72) driven by an electric motor is
used to extend
or retract the platform (18) horizontally along the second support member (16)
away from or
towards the first support member (14) respectively. In one embodiment, the
electric actuator
(72) comprises a worm gear consisting of a shaft with screw thread (the worm)
which meshes
with a toothed wheel (the worm wheel) to convert rotary motion into linear
motion, thereby
extending or retracting the platform (18) horizontally along the second
support member (16)
away from or towards the first support member (14) respectively.
In one embodiment, an electric motor (74) is positioned on the first support
member (14)
to drive a cable-driven system to enable vertical upward and downward movement
of the lifting
member (44). The first support member (14) includes upper and lower roller
bushings (76, 78) at
its ends. Gears (80) associated with the electric motor (74) drive the roller
bushings (76, 78),
along which stainless steel cable (not shown) is run. Cable runs from the
gears (80) to the upper
roller bushing (76) and extends to connect to the lower end of the lifting
member (44). Cable
also runs from the gears (80) to the lower roller bushing (78) and extends to
a spring (82) within
the lifting member (44). For moving the lifting member (44) vertically
upwards, the gears (80)
drive the upper roller bushing (76) and the cable pulls upwardly to elevate
the lifting member
(44). The lower roller bushing (78) meanwhile turns passively during this
movement. For
moving the lifting member (44) vertically downwards, the gears (80) drive the
lower roller
CA 02627562 2008-04-21
bushing (78) and the cable pulls downwardly via the spring to lower the
lifting member (44).
The upper roller bushing (76) meanwhile turns passively during this movement.
In one embodiment, a single portable hand control unit controls all operating
functions;
for example, while standing on the platform, the workman can safely and
conveniently raise or
lower the platform at the desired height, or extend or retract the platform to
the desired extension
distance. Additional control units can be provided in the vehicle, the vehicle
bed, or on ground
level to provide safety overrides or master or emergency shut-offs. A main key
disconnect
switch can be also provided to prevent unauthorized use.
In operation, the retractable aerial platform (1) is installed within the bed
(2) of the
vehicle (3), with the first and second support members (14, 16) in the closed
position, and the
frame (20) in the collapsed position as shown in Figure 1. The vehicle (3) is
driven to the
desired worksite and maneuvered into position adjacent the elevated structure
or site. As shown
in Figure 2, the aerial platform (1) is elevated into a full upright position
using the control unit.
If desired, electric or manual levelers (not shown) may be lowered prior to
operating the aerial
platform (1) to minimize truck roll. As shown in Figures 3 and 4, the lifting
member (44) is
electrically lowered short of ground level. The platform (18) naturally folds
down to provide
easy and safe access, as shown in Figure 5. The workman can then erect the
frame (20) from a
collapsible to a fully interlocked and upright position (shown in Figure 6) by
pulling upwardly
on the hand rails (54). The workman can then stand upon the platform (18).
Using the single
portable control unit or assistance from other workmen operating control units
in the vehicle or
at ground level, the workman can adjust the height (as shown in Figures 6 and
7) and extension
distance (as shown in Figure 9) of the platform (18) to begin work funetions.
Once the work has been completed, the lifting member (44) is lowered short of
ground
level. In one embodiment, the platform (18) is safely lowered by multiple
stops and starts. In
one embodiment, a gear drive brake is included to avoid back drive or slippage
on momentum as
the platform (18) is lowered. The workman can then exit the platform (18) and
fold the frame
(20) into the platform base (18) (Figure 5). The lifting member (44) is raised
to nest between the
rollers (46) in preparation for closing (Figure 2). The aerial platform (1) is
then lowered into its
closed position within the bed (2) of the vehicle (3). The platform (18)
automatically drops back
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to rest on top of the first support member (14) (Figure 1).
The embodiment of the invention described above is directed to a retractable
aerial
platform (1) that is mountable on the bed (2) of a vehicle. However, one
skilled in the art will
understand that the retractable aerial platform (1) of the present invention
is not restricted to
vehicle mounting and it can be mounted to any stable and substantially
horizontal surface that
will support the weight of the apparatus. Figure 10 depicts an embodiment
where the retractable
aerial platform is mounted to a horizontal surface.(5).
The present invention is advantageous over designs of the prior art.
Importantly, there is
provided a vertically and horizontally-controlled retractable aerial platform
which allows the
workman to adjust both the height and extension distance of the platform so
that work funetions
can be readily performed. The aerial platform is portable, compact and
suitable for use in a
variety of commercial vehicles. The aerial platform features safety and fall
protection by
inclusion of hand rails, side rails and crossbeams within the frame; a slip-
resistant platform
surface; and a single portable hand control unit operable by a workrnan on the
platform. The
aerial platform is constructed of durable materials which can withstand heavy
industrial and cold
winter environments. Minimal handling is required since both assembly and
disassembly of the
aerial platform are electrically or hydraulically operated, or by a
combination of both.
As will be apparent to those skilled in the art, various modifications,
adaptations and
variations of the foregoing specific disclosure can be made without departing
from the scope of
the invention claimed herein.
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