Note: Descriptions are shown in the official language in which they were submitted.
CA 02292486 1999-12-17
DETACHABLE TRUCK-MOUNTED LOADING DEVICE
BACKGROUND OF THE INVENTION
Storage compartments for tricks and trailers are generally raised well above
ground level
and require either an elevated loading platform or some type of loading device
to transfer freight to
and from a raised floor in the truck storage compartment. A typical loading
device is a fork lift
track or the like that is located at the loading or unloading site. When the
truck is transported to a
remote location for unloading or loading freight, it is necessary to have a
forklift truck or loading
dock at that location as well. It is expensive and sometimes not possible to
have a loading device at
every location where freight is to be loaded or unloaded. Conventional tail
gate mounted lifts are
expensive and are difficult and time consuming to mount on a truck and are not
easily movable from
one truck to another.
An object of the present invention is to provide a detachable truck-mounted
loading
device that can be easily mounted and dismounted from the interior of a
storage compartment of a
truck so that freight can be loaded or unloaded at any location.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, a detachable truck-mounted loading
device for
loading and unloading freight .from an elevated storage compartment in a truck
comprises a base
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that is removably mountable on the floor of a tn~ek storage compartment in a
predetermined
mounting position. A lift mechanism is movably mounted on. the base for
movement between
extended and retracted positions, wherein the lift mechanism is positioned
outside and inside the
storage compartment, respectively. The lift mechanism has a vertically movable
lift member and a
drive mechanism that reciprocates the lift member upwardly and downwardly
between raised and
lowered positions, the lowered position generally being at ground level below
the floor. The lift
member extends outwardly through a storage compartment access opening so as to
be vertically
movable between its raised and lowered positions when the lift mechanism is in
its extended
position. The lift mechmism is positioned in its raised position inside the
storage compartment
when the lift mechanism is in its retracted position.
In the preferred practice of the present invention, the lift mechanism is
pivotally mounted
on the base for rotation about a vertical axis. The lift mechanism rotates
through air angle of at least
90° in moving between extended and retracted positions. Freight can
easily be loaded on the lift
member when the lift member is positioned inside the truck, and freight can
easily be transferred to
the ground or other lowered position outside the truck by rotating the lift
mechanism to its extended
position and tlzen lowering the lift mechanism.
When the lift mechanism is in its retracted position, the lift mechanism is
entirely within
the storage compartment of the truck so as to permit any doors of the truck to
be closed and to
protect the lift mechanism from exposure to the elements.
The loading device can be detached from one truck and moved to another truck
o.r
Location as the. need arises by releasing fasteners that are used to mount the
device to this truck
storage compartment.
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The loading device can be installed or removed from a truck in a short period
of time.
The entire mechanism is placed in a. corner of a truck adjacent an access
opening and is fastened to
the floor with as few as two bolts. The hydraulic lift mechanism can be
powered by a gas engine or
a battery powered electric motor. When batteries are used, the batteries can
be recharged with a
S separate charger or by the charging system of the truck.
Desirably the lift mechanism has a fork assembly or a platform which serves as
the lift
member. The fork assembly or platform folds up against the lift mechanism in
order to allow room
to load and unload the truck with a forklift or pallet jack. When folded down
and lowered to the
tnGCk floor level, the lift member can be loaded or unloaded.
The mechansm includes a control mechanism that permits the load to be lifted
and
swung out the back of the truck, then lowered to the ground level, or loaded
from ground level up
into the truck. The control meclianism desirably is an electronic push button
control when the
mechanism is powered electrically and is a lever operated valve mechanism when
gas engine
powered hydraulics are used.
The entire truck loading device is mounted inside the truck storage
compartment when in
its retracted position. Thus, the unit can be installed in trucks with swing
or overhead doors, and the
mechanism is not exposed to elements of the road when the truck is operated.
An advantage of the present invention is that the truck contains its own
loading and
unloading mechanism at all times and is not handicapped by having to load or
unload freight from a
remote location where a forklift or loading dock is unavailable. Further, the
expense of separate
loading and unloading devices at each loading site is avoided. Also, with the
mechanism being
bolted to the truck flour, the entire mechanism easily can be moved from truck
to truck as the need
arses.
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These and other features and advantages of the present invention are described
in detail
and apparent frolil the preferred embodiment of the present invention
described in detail below and
show~~ in the appended drawings.
BRIEF DESCRIPTION OF
THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a perspective view of the rear end of a storage compartment iii a
track, showing the
manner in which the loading device of the present invention is mounted in the
truck, with the lift
mechanism being shown in its retracted position.
FIG. 2 is a perspective view of the loading device of FIG. 1, with the lift
mechanism being
shown in its extended and raised position.
FIG. 3 is a vi ew of the loading device of FIG. 2, with the Lift member being
shown in its
extended and lowered positions.
FIG. 4 is a view of the loading device FIG. 3 showing a pallet being mounted
on the lift
member in its extended and lowered positions.
- FIG. 5 is a perspective view of the loading device of FIGS. 1-4 with a
wheeled rack
mechanism being shown mounted on forks of the lift mechanism.
FIG. G is a side elevational view of the loading device showing the lift
mechanism in its
raised and extended positions.
FIG. 7 is an end elevational view of the loading device of the present
invention taken from
the end of the truck.
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F'IG. 8 is a fragmentary el.evational view showing the folding mechanism of
the loading
device, whereby the fork loader can be folded inwardly against the liFt
mechanism.
FIG. 9 is a sectional view taken along lines IX-1X of FIG. 8.
FIG. 10 is a fragmentary side elevational view showing the track mechanism
whereby the
lift member is raised or lowered in the left mechanism by wheels that ride on
a verl:ical track.
FIG. 11 is a fragmentary and partially schematic side elevational view showing
the manner
in which the lift member is raised or lowered by a hydraulic drive member
operating through a
chain drive mechanism.
FIG. 12 is a sectional plan view taken along lines XII - XII of FIG. 6,
showing the manner
lU in which the lift mechanism is pivotally mounted on the base and rotated by
a hydraulic drive
mechanism.
FIG. 13 is a fragmentary side elevational view showing the one embodiment of
an
attaclunent mechanism for mounting lifting forks on a transverse fork support
member.
FIG. 14 is a fragmentary perspective view of a second embodiment of an
attachment
mechanism for mounting lifting forks on the transverse fork support member.
FIG. I S is a side elevational view of the attachment mechanism of FIG. 14.
F1G. 16 is a view taken along lines I6-16 of FIG. 15.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings, a detachable truck mounted loading device 10 is
shown in
FIGS. 1-5 in various stages of operation, mounted at a roar corner of a
storage compartment 14 of a
truck 16. The storage compartment includes a floor 18, side walls 20, and a
top 22. An access
opening 24 is provided at the rear end of the thick adjacent a rear edge 26 of
the floor. The access
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opening can be enclosed by an overhead door 28 or by swinging doors {not
shown), which are
conventional. The rear edge 26 of the track and the floor 18 of the track are
positioned above the
ground 30, with the ground rcpresentuig a lowered position below the level of
the floor of the
storage compartment.
S Referring to FIG. 2, loading device 10 comprises a base 32 that is mounted
by suitable
fasteners shown as bolts 34 to the floor of the. storage compartment. The
fasteners are releasable to
mount and dismount the loading device from the storage compactmelit of the
truck. Base 32
comprises a flat plate 31 mounted on rails 33 that abut the floor at the
corner of the storage
compartment. A cross member 35 extends between the rails under the lift
mechanism. The ends of
rails 33 extend rearwardly from the plate. Bolts 34 extend through opening in
the exposed ends of
each plate and then through openings in the floor 18 of the truck. A
reinforcing plate 39 is
positioned on the underside of the floor. The bolts extend through openings in
the reinforcing plate
and are secured in position by nuts 41. The end of each rail 33 has a number
of available openings
43 in it {FIG. I 2) so the bolts can be positioned to miss contact with one of
the truck floor support
members 45 that generally are positioned under a truck floor (FIG. 6). With
this fastening method,
two bolts we all that is necessary to mount the lift in place. The lift can
thus be mounted and
removed in minutes.
A lift mechanism 36 is mounted on the base 32 by means of a vertical pivot
shaft 38
extending upwardly from the base. The loading mechanism is laterally rotatable
about the axis of
the vertical pivot shaft. The loading mechanism comprises a fxed support frame
40 that includes
side rails 42 at the bottom of the frame and cross members 44 and 45 extending
across the side rails.
Cross member 45 is centrally located and is attached to vertical pivot shaft
38. The support frame is
mounted on wheels 46 and 48, with the wheels being oriented for rotation in an
arcuate path around
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the axis of pivot shaft 38. The support frame is rotated by means of a double
acting hydraulic
cylinder 50 (FIG. I2) pivotally attached to base 32 at one end by a connector
52. Output shaft 54 is
pivotally attached at an outer end by a connector 56 to the support frame at a
position spaced apart
from the axis of pivot shaft 38, desirably at an end of cross member 45.
Actuation of the hydraulic
cylinder SO rotates the support frame for moving the lift mechanism between
its extended and
retracted positions.
A pair of U-shaped channels GO are attached to forward ends of side rails 42,
with the U-
shaped channels each facing outwardly in opposite sideways directions.
A vertically movable lift frame 62 comprising a pair of spaced vertical rails
64
interconnected by cross member 66 is mounted for vertical movement along the U-
shaped interior
of channel 60 by means of a pair of vertically-spaced wheels 68 and 70. Each
pair of wheels is
mounted on a vertical mounting plate 72, which is turn mounted to a horizontal
frame member 74
and 76 at the upper and lower ends of the mounting plate. The horizontal frame
members extend
outwardly and join vertical rails 64. Cross members 78 and 80 hold the frame
members and
1 S mounting plates and wheels in position.
As shown in FIGS. 2 and 3, movable lift frame 62 can moved from a raised
position
shown in FIG. 2 to a lowered position shown in FIG. 3 when the lift mechanism
is rotated to its
extended position wherein movable lift frame 62 protrudes outwardly through
access opening 24.
Channel members 60 form a vertical track for the upward and downward movement
of the movable
frame.
At a lower end of the movable lift frame, a load supporting mechanism, such as
a
platform (not shown) or a fork assembly 92, is mounted on a pivot frame 82,
with the pivot frame
being attached by a pivot rod 84 to the lower end of movable lift frame 62.
Pivot frame 82
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comprises an outwardly extending beam 86 which is attached at an Timer end to
pivot rod 84. A
vertically extending ann 88 extends upwardly from the inner end of beam 86 to
an angular
reinforcing member 90 that extends downwardly and outwardly from the upper end
of ann 88 to
beam 86.
The lifting mechanism, such as fork assembly 92, can be attached to beam 86.
In the
illustrated embodiments, the fork assembly includes a pair of forks 94 that
are removably attached
to the beam by releasable brackets. In FIG. 13, a~~ L-shaped arm 96 is mounted
on an iraier end of
fork 94 to form a C-shaped bracket that f is over the rectangular beam.
Fasteners 98 extend
downwardly through outer ends of the C-shaped bracket and screw into threaded
sleeves mounted
on the inner ends of the forks to hold the lifting forks on the beam. These
fittings can be released
for removal and replacement of the lifting forks. The lifting forks can be
replaced by a flat platform
or other suitable lifting device that may be attached to the support beam 86
in a manner similar to
lifting forks 94.
A preferred fork assembly mounting bracket 150 is shown in FIGS. 14-16.
Mounting
bracket 150 comprises a flat plate 152 welded to the top of the inner end of
fork 94. The plate is
wider than the fork, and openings 154 are formed in edges of the plate that
extend past the fork. A
pair of U-bolts 156 fit over the beam 86 on each side of fork 94 and fit
through the openings 154.
Nuts 158 thread on the ends of the U-bolts to lock the fork in a desired
location on the beam 86.
As shovv~l in FIGS. 4 and 5, fork assembly 92 can be used to support a pallet
100, a rack
102, a pallet jack, or any other type of load support.
The manner in which the lift member (which includes the movable frame and
forks or
platform at the bottom of the frame) is raised or lowered in the lift
mechanism is illustrated in FIG.
11. A hydraulic cylinder 106, which can be a single or double acting hydraulic
cylinder (a double
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acting cylinder enhances the lowering rate of the lift), is mounted at a lower
end 107 to support
frame 40 and includes an extendable output shaft 108 that extends from an
upper end of the cylinder
to an upper end 110, which is attached to cross member 112 extending between
channels 60. A pair
of sprockets 114 are mounted to cross member 112 for rotation about an axis
parallel to cross
member 112 on opposite sides of hydraulic cylinder shaft 108. Chains 116
extend over the
sprockets and are attached at one end 1 I8 to the movable frame and at another
end 120 to a cross
member 122 of fixed support farm 40. When output shaft 108 is extended and
retracted, the output
shaft bears against the chain (which is a link chain), and causes movable
frame 62 to be raised and
lowered, raising and lowering the lift mechanism between raised and lowered
positions. The chain
has the effect of doubling the travel of the drive mechanism, with the lift
mechanism moving twice
as far as the extendable output shaft as the extendable output shaft is raised
and lowered. This is an
important feature of the present invention, because it makes it possible to
lift a load with a hydraulic
cylinder that is half as long as a cylinder would have to be without the chain
drive mechanism .
Another important feature of the present invention is the fact that the load
supporting
members of the lift mechanism can be pivoted upwardly against the support
frame and moved out of
the way for storage purposes. This construction is shown in FIGS. 8 and 9. The
lift member is
shown in a folded position in FIG.1.
Referring to FIGS. 8 and 9, angular member 90 has a stop member 120 extending
inwardly toward member G4 at an upper end thereof. A mating stop member 122
extends ourlvardly
from the side of member 64 so as to be opposed to member 120. Stop members 120
and 122 have
mating beveled surfaces that engage and draw members 90 and 64 inwardly toward
each other as
fork support beam 86 is pivoted downwardly to a horizontal position.
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Stop members 120 and 122 thus securely hold the beam 86 in a horizontal
position.
When desired, the lifting mechanism can be pivoted upwardly about the axis of
pivot rod 84 until
the support beam SG is substantially vertical. This permits the lifting device
to occupy less space in
the back of the truck when the device is not in use and also permits other
types of loading devices
such as a fork lift truck to load things on to the truck at a position
adjacent to the lifting device of
the present invention.
The hydraulic cylinders of the present invention can be powered by a hydraulic
pump 114
mounted on the support frame. A gas engine or battery powered electric motor
can be provided to
operate the hydraulic pmnp. The batteries can be charged by a charger or can
be connected to the
electrical system of the truck.
While the two bolt mounting mechanism is all that is required to hold the lift
in place for
even heavy loads, for very heavy loads, it is also possible to employ
counterweights 130 in the form
of steel blocks or the like on the support frame on the opposite side of the
pivot axis from the lifting
mechanism. Also, counterweights 134 may be placed on the base plate 32 on the
side opposite the
lift mechanism. These counterweights can be steel blocks or the like. The
counterweights will hold
the lift mechanism in position and minimize the tendency of the lifting
mechanism to tip outwardly
when a heavy load is placed on the lift mechanism. However, the bolts alone
are generally
satisfactory. This makes the available truck load higher and makes it easier
to install and remove
the lift.
In operation, a lifting device is stored in the position in FIG. 1. The fork
assembly is then
pivoted down and the lift mechanism pivoted outwardly to the position shown in
FIG. 2. The lift
member can then be lowered as shown in FIG. 3 for purposes of loading or
unloading freight from
the truck storage compartment.
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The loading device can be detaclied from one truck and installed in another
simply by
releasing fasteners 34 that hold the base to the floor of the truck. The whole
loading device can be
moved from the truck to a new location. The loading device preferably is
mounted on a truck but
could of course be mounted on a loading platform or other location.
The entire operation is controlled by a control panel 140 mounted in a
convenient
location on the support frame. The control panel can be a push button operated
electrical panel,
which controls an electrically operated lift, or it can be control levers for
operating a valve control
system of the type that can be used with a gas engine powered system. The push
buttons or levers
will control the extension and retraction of the lift mechalusm and the
raising and lowering of the
lU liil member. The fork or platform assembly is folded manually.
It should be understood the foregoing embodiment is merely exemplary of the
preferred
practice of the present invention and that various changes in the arrangements
and details of
construction of the embodiment disclosed herein may be made without departing
from the spirit and
scope of the present invention.
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