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| United States Patent | 3976209 |
| Link to this page | http://www.wikipatents.com/3976209.html |
| Inventor(s) | Burton; Edward E. (19418 Lemarsh St., Northridge, CA 91324) |
| Abstract | A folding loading ramp for attachment to the end gate of pickup trucks. The
ramp is of such a construction so that it may fold up with the tailgate,
take up minimal additional space, and not interfere with the normal use of
the end gate of the truck. The ramp includes a number of foldable ramp
members which are hinged to make a convenient ramp for hard to load items,
such as garden tractors, motorcycles, snowmobiles, etc. Added support is
given to the ramp by a supporting mechanism which folds within the ramp
members when not in use. The supporting mechanism reinforces the ramp by
virtue of its structure rather than by contact with the ground. This
allows folding of the support mechanism within the ramp members for space
saving and provides support when the loading ramp is used with a loading
dock. A combination handle and locking mechanism allows for positioning
the ramp as a space extension for the vehicle bed and pulling the ramp to
an extended position from the folded position. |
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Title Information  |
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Drawing from US Patent 3976209 |
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Pick-up truck loading ramp |
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| Publication Date |
August 24, 1976 |
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| Filing Date |
August 9, 1974 |
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Title Information  |
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Description  |
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BACKGROUND OF THE INVENTION
This invention relates to a device for loading cargo onto the bed of a
truck and more particularly relates to a foldable ramp attached to the
tail gate of a pickup truck.
The loading and unloading of bulky or heavy objects from a vehicle for
purposes of delivery to the consumer or use at another location by the
owner presents many problems. Frequently, the weight and size of the
object is sufficiently great that at least two persons are required to
lift it to the bed of the transferring vehicle and, on many occasions,
normal loading is completely impossible. Even with sufficient manpower,
constant threat of injury hinders operations. As a result, costs and
schedule are detrimentally effected.
Different types of loading devices have been proposed to alleviate these
problems. Such devices include lift trucks and hoists. However, these
devices are extremely expensive to purchase and are not justified unless a
high volume of heavy merchandise is being moved by a particular vehicle.
Consequently, loading ramps adopted to form an inclined surface from the
ground to the bed of the vehicle over which the goods may be moved have
been proposed. U.S. Pat. Nos. 3,339,968 to Hall and 3,352,440 to Wilson
disclose such ramps which are attached to the truck tail gate.
However, these ramps have also been unsuccessful in that they do not
combine the previsions of being foldable with sufficient structural
qualities to withstand heavy loads. By being foldable space was conserved,
but at the expense of load bearing capabilities, especially at the hinge
between the ramp members.
U.S. Pat. No. 2,727,781 realized this problem and provides a plurality of
pivotable legs for support at the hinge. However, this approach only
supports the hinge and not the two ramp members. Further, this device is
impractical as a plurality of hinged legs is expensive and requires extra
space for the legs when folded. This device requires the legs to touch the
ground for support. If the ramp is elevated as when receiving items from a
loading dock, blocks must be placed under the legs. This requires time in
finding the blocks and placing them under the legs and is not at all safe.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an
efficient, practical, versatile, and inexpensive foldable ramp for the
loading or unloading of bulky or heavy objects from a vehicle.
It is another object of the present invention to provide means for
reinforcing the loading ramp when the ramp is extended into loading or
unloading position which supports the hinge between the ramp members and
the ramp members.
It is yet another object of the present invention to provide a means for
reinforcing the loading ramp when the ramp is extended into loading or
unloading position which is foldable and adds support by virtue of its
structure and connection to the ramp members and hinge rather than by
contact with the ground.
It is still another object of the present invention to provide a ramp which
is safely and adequately reinforced when extended from the truck bed to
the ground or from the truck bed to a dock.
An additional object of this invention is to provide a device of the type
described which is capable of serving as a truck bed space extension in a
simple manner as well as a loading and unloading ramp.
Further, another object is to provide a reinforced loading ramp where no
extra space is required for the reinforcing means when the loading ramp is
folded.
Briefly, in accordance with the invention, there is provided a pickup truck
loading ramp having two foldable ramp members. A connecting means is
provided for pivotally connecting one of the ramp members to the truck and
gate. Another connecting means pivotally connects the ramp members to one
another. A foldable supporting means is connected to the latter connecting
means and the ramp members when the ramp members are extended to the
loading or unloading position. The supporting means provides reinforcement
by its structure and connections.
Other objects and advantages of the invention will become apparent upon
reading the following detailed description and upon reference to the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the loading ramp attached to the tail gate
of a pickup truck and in the extended position from the truck bed to the
ground;
FIG. 2 is a fragmentary sectional view of the loading ramp of FIG. 1 taken
in the direction of arrows 2--2 of FIG. 1;
FIG. 3 is a sectional view of two ramp members in the folded position;
FIG. 4 is a fragmentary bottom plan view taken in the direction of arrows
4--4 of FIG. 2 of the loading ramp and illustrating the supporting
mechanism;
FIG. 5 is a fragmentary sectional view of the connection of the supporting
mechanism to the ramp members and internal structural details of the ramp
members taken in the direction of arrows 5--5 of FIG. 2;
FIG. 6 is a detail perspective view of the handle-locking mechanism with
the handle in the recessed position as shown by the broken line and in the
extended position by the solid line;
FIGS. 7a, 7b, 7c, and 7d illustrate various positions of the loading ramp
relative to the truck bed;
FIG. 8 is a fragmentary sectional view of the handle-locking mechanism
employed in the locking position taken in the direction of arrows 8--8 of
Figure 7c.
While the invention will be described in connection with the preferred
embodiment, it will be understood that it is not intended to limit the
invention to those embodiments. On the contrary, it is intended to cover
all alternatives, modifications, and equivalents that may be included
within the spirit and scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION OF THE INVENTION
Turning first to FIG. 1, there is shown an example of carrying out the
invention, wherein a loading ramp, generally indicated at 10, is connected
to the end gate 12 of a pick up truck 14. The loading ramp 10 is
illustrated in the extended position for loading or unloading articles
from the truck bed 16 to the ground.
A pair of chain 18 attached to side panels 20 and end gate 12 normally
restrain the pivotal movement of the end gate 12 to a position parallel to
the bed 16. When this is the case, chain extensions 22 can be added to
chains 18 by attaching each of the hooks 19 at the end of chains 18 to a
link of chain extension 22, and the hook 21 at the end of each of the
extensions 22 to a link 23 attached to end gate 12 so that end gate 12
will be oriented angularly downward at this extended position.
Loading ramp 10 typically includes upper and lower members 24 and 26
respectively. Upper ramp member 24 is pivotally attached to another ramp
member 28 by a hinge 29. Ramp member 28 is secured to the inner surface of
the end gate 12 by any suitable means such as bolts (not shown).
Preferably, the length and width of ramp member 28 are approximately the
same as end gate 12 so that ramp member 28 substantially covers the entire
surface area of end gate 12 to allow handling of the widest possible
loads. A handle 30 is provided within a recess 32 in lower ramp member 26
for ease in pulling the ramp 10 to an extended position from the folded or
closed position. Handle 30 as will later be explained also functions as a
locking member with a lateral slot 34 in ramp member 24 for utilizing the
ramp 10 as a truck bed space extension.
Referring now to FIGS. 2 and 3, ramp members 24 and 26 are pivotally
connected to each other by a hinge 40. The hinge 40 and members 24 and 26
are reinforced by one or more supporting mechanisms generally indicated at
50. Supporting mechanism 50 comprises four longitudinal struts 51, 52, 53,
and 54 and a central strut 55. Struts 51 and 54 are pivotally joined at 56
while struts 53 and 54 are pivotally joined at 58. Struts 51 and 54 are
pivotally connected to ramp members 24 and 26 respectively by hings 60. A
joint 62 pivotally connects struts 52 and 53. The central strut 55 is
fixedly connected to joint 62 and hinge 40. In the extended position as
shown, support means 50 forms a truss. Forces applied to ramp members 24
and 26 anywhere along the length of the truss or to hinge 40 are supported
by the truss. The applied forces are internally distributed to the struts
of the truss and the ramp members 24 and 26 by the truss structure. The
applied forces are thereby absorbed or supported by the truss with each of
the elements in tension or compression depending on the direction,
location, and amount of the applied forces.
The support means 50 can be folded in the direction shown by arrows 61 and
64 by application of a transverse force, i.e., perpendicular to the
extended longitudinal struts, to the joints 56 and 58 or longitudinal
struts and inward rotation of ramp members 24 and 26. A longitudinal
groove 70 is provided in both ramp members 24 and 26 for each supporting
member 50. Thus, as shown in FIG. 3, when ramp members 24 and 26 are in
the folded position, the support mechanism is folded within ramp members
24 and 26 with the bulk of the support means 50 within grooves 70 so that
little or no additional space is taken up by the ramp 10 due to the
support means 50 when the ramp is the folded position.
As can best be seen in FIGS. 2 and 5, ramp members 24 and 26 have a top
skin 80 and a bottom skin 82 which can be of any suitable material such as
steel or aluminum affixed together as by welding. The loading surface of
members 24, 26, and 28 is optimally covered by an anti-skid material such
as a Deck-Tread paint to prevent load slippage. Members 24 and 26 are
hollow between the top skin 80 and bottom skin 82 to minimize weight and
cost. A foam material 84 such as styrofoam is preferably fitted within the
hollow portions to increase compressive strength of the ramp while not
significantly increasing weight or cost of the ramp 10. The top skin 80
also forms the ends of members 24 and 26. The top skin 80 continues on the
bottom of the ramp members 24 and 26 for a distance corresponding to the
length of hinge 40, then upward to the top of ramps 24 and 26 where it is
flanged at 86 and affixed.
The grooves 70 are formed by a longitudinal hat section 86 which also
constitutes the bottom skin 82. The indented portion 70 of the hat section
86 constitutes the groove 70. Hat section 86 is suitably affixed to
another longitudinal hat section 90 which is secured to top skin 80. Hinge
60 is mounted over a spacer 92 to allow for a cylindrical pin 96 in the
hinge 60. Hinge 60 is suitably secured to hat section 86 as by spot
welding. Ramp member 28 is preferably completely hollow and optimally is
filled with a foam.
FIGS. 6 and 8 illustrate the handle-locking mechanism of the present
invention. The handle 30 is a standard T-handle which is pivotally
connected by a hinge 100 to the top skin 80 within recess 32 of ramp
member 26. Hinge 100 is rotatively mounted within an aperture 102 in
recess 32 which extends through member 26 by being connected to a flanged
end 103 of a bar 104 in aperture 102, the bar 102 also having another
flanged end 106. The flanged ends 103 and 106 are positioned on both sides
of aperture 102. Fixedly attached to flanged end 106 is rod 108 with a
detent 110.
Handle 30 can be withdrawn from recess 32 when it is desired to pull the
ramp 10 to an extended position. For locking ramp members 24 and 26
together, detent 110 is placed longitudinally within longitudinal slot 34
and rotated by handle 30 so that the detent 110 prevents separation of
ramp members 24 and 26 by catching on the underside of bottom skin 82 of
member 24. For unlocking, the handle 30 is rotated until detent 110 is
aligned with longitudinal slot 34 and it can thereby be removed. As handle
30 is within a recess 32 and uses a slot 34 in member 24 for locking, no
additional storage space is required when the ramp 10 is in the folded
position.
OPERATION
The versatility and operation of the present invention are illustrated in
FIGS. 1, 7a, 7b, 7c, and 7d. FIG. 7a shows the ramp 10 in the closed or
folded position. The only extra storage space used is the thickness of
members 24, 26, and 28. The ramp 10 can be extended from the folded
position to the ground by lowering tail gate 12, unlocking ramp members 24
and 26 using handle 30, and rotating the ramp members 24 and 26 outward
using handle 30. This procedure is reversed for moving the ramp 10 to the
closed position. FIG. 7b shows the position of ramp 10 when the end gate
12 is down for the purpose of space extension of bed 16. In this position
ramp member 26 is folded inward after tail gate 12 has been lowered. FIG.
7c shows the use of the ramp as a space extension for bed 16 beyond the
end gate 12. For this position, the ramp member 26 is rotated outward
after the end gate 12 is lowered with the members 24 and 26 retained in a
locked position by detent 110. FIG. 7d shows the ramp 10 used with a
loading dock 120. Ramp 10 is simply fully extended and then lifted to rest
on loading block 122 of loading dock 120. In this position the ramp
members 24 and 26 and hinge 40 are still reinforced by the supporting
means 50.
Thus, it is apparent that there has been provided, in accordance with the
invention, a truck loading ramp that fully satisfies the objects, aims,
and advantages set forth above. While the invention has been described in
conjunction with specific embodiments thereof, it is evident that many
alternatives, modifications, and variations will be apparent to those
skilled in the art. Accordingly, it is intended to embrace all such
alternatives, modifications, and variations as fall within the spirit and
scope of the appended claims.
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Description  |
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