Note: Descriptions are shown in the official language in which they were submitted.
CA 02464240 2004-04-13
42206-0001
HEIGHT-~I3JUSTA~LE TIaAILEII. HITCH
BAC.t~OROUIV~D ~F THE INVEI~I~TIC)N
Field of Invention
[0001] This invention relates to the field of transportation and more
particularly to a
vehicle accessory for towing and maneuvering 1-railers.
Description of the Related Prior Art
[0002] As those in the art will appreciate, the towing of a trailer by a
towing vehicle
such as a pick-up tmek involves fixably mounting a hitch ball to a supporting
structure of
the towing vehicle, such as to a rear bumper of the vehicle. Conventional
hitch balls have
a spherical head portion, a flange portion with a threaded stem, and a neck
portion
spacing the head portion above the flange portion. A typical mounting, such as
is
presently found on some light pick-up trucks, includes a hole formed in a
shelf portion of
the rear bumper for receiving the stem, which is fastened by a nut that
threadingly
engages the stem. Alternately, a rearwag°dly extending rectangular
socket is formed in the
hitch mount for receiving a rectangular hitch shank. The shank may have formed
therein
a hole for receiving the stem of the ball, but more commonly a flange such as
described
above is welded to the shank in offset relation thereto. 'fhe shank is
typically fixedly
retained in the socket by a clevis pin or bolt fastener that engages aligned
transverse
openings of the shank and the socket.
[0003] Several trailer hitches provide for vertical adjustment of the trailer
hitch ball
relative to the towing vehicle to accommodate different towed vehicles and/or
different
loadings of the towed and/or towing vehicle. See, for example, U.S. 4,033,601
to Lindahl
et al., which discloses a hitch ball which can be physically removed fr~m the
mount and
repositioned vertically within a limited range. U.S. 4,103.,32 to Sheppard,
Jr., discloses
a hitch which is able to adjust the vertical offset within a limited range
while the towed
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vehicle is already coupled to the ball. This hitch includes a mounting plate
for vertically
oriented attachment to the trailer hitch of the towing vehicle, a slide plate
.moveable up
and down with respect to the mounting plate by means of a jack screw, and a
tongue
projecting rearwardly from the slide plate for receiving the ball. The
arrangement is
problematic because the hitch is awkward to use in that a separate device is
required for
turning the jackscrew. US 6,663,133 to l~osenlund overcomes this deficiency by
providing, among other things, a crank for manually tumin,g the jackscrew.
However, like
the prior art, this device is focused on providing sufficient clearance for
various towed
vehicles having widely varying loads to ensure that the towed vehicle does not
strike the
ground when in motion. The range of motion provided is also restricted to the
small
vertical range required to manage the clearance problem.
[0004] As will also be appreciated by those in the art, i;here are numerous
devices for
easily and quickly aligning the tongue and hitch of a trailer with the ball on
a towing
vehicle, and for lifting the tongue and hitch on and off the ball. U.S.
5,882,029 to
Kennedy for example discloses a trailer hitch alignment and lifting device
which
comprises a vertical post on or connected to the towing vehicle in front of
and in close
proximity to the ball. The post has a pivotal arm which can rotate from a
vertical position
to a rearwardly inclined position. The post has a cable guide at or near its
top surface.
The pivotal arm also has a cable guide at or near its top surface. The cable
guides are for
receiving and guiding a cable connected to a winch on the tongue of the
trailer. The
tongue of the trailer also has a cable guide in front of the winch near the
front end of the
tongue. The winch in combination with the pivotal arm allows for some vertical
movement of the trailer to facilitate aligmnent and placement onto the ball.
[0005] Although the above devices work adequately for their intended purposes,
they
do not provide for a trailer hitch which facilitates easy unloading and
loading of a trailer
attached thereto. The prior art does disclose various tilting trailers which
assist loading
and unloading activities. U.S. 5,924,836 to Kelly for example, provides a
trailer with a
bed in which the rear section of the trailer can be rotated downwardly with
respect to the
front to form a ramp. However, it would be preferable to have a universal
trailer hitch
which could assist with loading and unloading such that a.ny utility trailer
could be used.
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The prior art discloses at least two such trailer hitches. U.S. 4,929,028 to
Underwood
discloses a hitch apparatus which may be conveniently mounted to a vehicle for
use in
hitching a trailer and for lifting one end of the trailer with respect to the
vehicle. It uses
an hydraulic mechanism for extending and contracting an hydraulic cylinder
from a
stowed position to an extended position. U.S. 6,155,588 discloses a hitch
apparatus which
incorporates a pair of pneumatic shocks to allow a main body assembly to
rotate from a
contracted to an extended position. )3oth of these devices have relatively
restricted range
of vertical motion and utilize parts which cannot be readily replaced or
repaired without
the assistance of a professional.
[0006) It is therefore an object of the present invention to provide an
adjustable trailer
hitch which overcomes the deficiencies of the prior art. It is also an object
of this
invention to provide a self contained hitch apparatus which can be readily
attached to a
conventional pick-up truck without major modification of the vehicle frame.
Another
object of the invention is to provide a hitch apparatus which has a wide
vertical range of
motion. It is still another object of this invention to provide a hitch
apparatus which can
be installed, operated and maintained by a vehicle owner having limited
technical
knowledge.
SUMMARY ~F THE INVENTION
[0007] The above objects are provided by an adjustable trailer hitch which
allows the
hitch ball to be easily raised from a lowered position to a raised position.
The hitch ball is
attached to a receiver assembly which slides vertically in a guide. The guide
includes a
tail piece which can be inserted into a standard socket extending from the
towing vehicle.
At the top of the guide is positioned a winch, the cable from which is
attached to the
receiver assembly.
[0008] In accordance with one aspect of the invention there is provided a
height-
adjustable trailer hitch for a towing vehicle to facilitate loading and
unloading of a towed
vehicle coupled to the height-adjustable trailer hitch comprising: a main unit
vertically
mounted to the towing vehicle, the main unit comprising a vertically oriented
guide; a
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receiver assembly adapted to slide along the vertically oriented guide; and a
lifting
mechanism fixed to the main unit and removably coupled to the receiver
assembly for
guiding the receiver assembly along the vertically oriented guide, wherein the
receiver
assembly can be vertically adjusted from a first position for towing the towed
vehicle to a
second position for tilting the towed vehicle.
[0009) Preferably, the lifting mechanism is a winch having a retrievable cable
extending therefrom, the cable is coupled to the receiver assembly, and the
winch is
releasably attached to a mounting plate extending from the main unit.
[00010) More preferably, the main unit comprises an elongate hollow tube
having a slot
formed therein and a tail piece for removable attaclunent to the towing
vehicle.
[00011 ) Even more preferably, the receiver assembly is positioned inside the
elongate
hollow tube and the receiver assembly further comprises a socket extending
perpendicularly from the slot for receiving a hitch ball assembly.
[00012) In accordance with a second aspect of the invention, there is provided
a height-
adjustable trailer hitch for a towing vehicle to facilitate loading and
unloading of a trailer
coupled to said height-adjustable trailer hitch comprising: means for
vertically guiding
said trailer from a towing position to a tilting position, the means for
vertically guiding
mounted to the towing vehicle; means for receiving the towed vehicle, the
means for
receiving adapted to slide along the means for vertically guiding; and means
for lifting
the means for receiving, the means for lifting fixed to the means for
vertically guiding
and removably coupled to the means for receiving, wherein said means for
lifting is
adapted to direct said means for receiving along a vertically oriented slot
formed in said
means for vertically guiding,
[00013] The advantage of the present invention is now readily apparent. Using
the
adjustable trailer hitch, it is possible to easily raise the ball on a towing
vehicle from a
towing position to a loading/unloading position by simply engaging the winch.
In the
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loading/unloading position the rear end of a towed vehicle {e.g. trailer) is
near the ground
to facilitate movement of a payload on or off the towed vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[00014] A better understanding of the invention will be obtained by
considering the
detailed description below, with reference to the following drawings in which:
Figure 1 depicts the present invention in assembled form;
Figure 2 depicts the main unit of the present invention;
Figure 3 depicts the receiver assembly of the present invention;
Figure 4 depicts the upper end of the present invention in assembled form
showing a
detailed view of the winch;
Figure 5 depicts the lower end of the present invention in assembled form with
a ball
hitch assembly attached to the receiver assembly of Figure 3;
Figure 6 depicts a cross-section of Figure 5 about the line A-A;
Figure 7 depicts a vehicle with the present invention attached thereto in the
tow position;
and
Figure 8 depicts the present a vehicle with the present invention attached
thereto in the
loading/unloading position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[00015] Referring to Figure l, there is depicted a perspective view of the
present
invention. The height-adjustable trailer hitch (shown generally at 10)
comprises main
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unit 12, receiver assembly 14 and lifting mechanism 16. Figure 2 highlights
main unit 12
which further comprises vertically oriented guide 18, and tailpiece 20
reinforced with
opposing gussets 21. Opposing apertures 22 are formed in the lower end of main
unit 12,
while another set of opposing apertures 24 are formed in tailpiece 20. Figure
3 depicts
receiver assembly 14 which includes main body 26 and socket 28 extending
perpendicularly therefrom. Formed in main body 26 and socket 28 are opposing
sets of
apertures 30, 32 and aperture 34. The purpose of opposing apertures 22, 24,
30, 32 and
aperture 34 will be described in relation to Figure 5. Figure 4 highlights
winch 38 which
is bolted to mounting plate 40 with bolts 42. As shown in the drawing,
mounting plate 40
is ~~elded to the upper end of vertically oriented guide I8. As will be
appreciated by
those in the art, winch 38 is manually wound using crank handle 41 and
includes a locking
mechanism 39 to prevent winch 38 from unwinding. As will also be appreciated
by those
in the art, although winch 38 shown in Figure 4 is of the manual type, winch
38 could
also be of the powered type (e.g. an electric winch which runs off the towing
vehicles
power supply) and such variation is meant to be included v~~ithin the scope of
the
invention.
[00416] Figure 5 depicts the Iower end of the height-adjustable txailer hitch
10 with a
ball hitch assembly (shown generally at 42) attached to receiver assembly 14.
As can be
seen, removable locking pin 46 extends through opposing apertures 22 and 30
and is
retained by a clip 47 (see Figure 6) to lock receiver assembly 14 in the
towing position.
Bolt 48 extends through aperture 34. Cable 50 extends from winch 38 along
vertically
oriented guide I8 and is secured to bolt 48 as more clearly shown in the cross-
sectional
view of Figure 6. Ball hitch assembly 44 comprises shank 52 which mates with
socket 28
and offset flange 54 to which hitch ball 56 is attached as is well known in
the art. A bore
(not shown) axially aligned with opposing apertures 32 receives retaining pin
58 (secured
by retaining clip 60) to ensure that shank 52 remains seated in socket 28.
[00017] Figure 6 is a cross-sectional view of Figure 5 about line A-A. As can
be seen in
the drawing, locking pin 46 (secured by clip 4 7) extends through vertically
oriented guide
18 and main body 26 to secure receiver assembly 14. As can also be seen, bolt
48 extends
through main body 26 and has attached thereto cable 50. With locking pin 46
removed,
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tension applied to cable 50 will cause receiver assembly 14 (along with hitch
ball
assembly 44) to move vertically along vertically oriented guide 18.
[00018] In a preferred embodiment, vertically oriented guide 18 is constructed
of an
elongate hollow square tube measuring 4"x 4°', 3/16" in thickness and
40°' long.
Vertically oriented guide 18 includes a slot 2 5/8"x 36" along the length of
the tube which
enables receiver assembly 14 with its protruding socket 28 to travel up and
down the
tube. Tailpiece 20 comprises a hollow square tube measuring 2'°x 2",
1/4" in thickness
and 11" long which is welded to the Lower end of vertically oriented guide 18
and
reinforced with gusset 21. Tailpiece 20 also includes opposing apertures 24,
measuring
41/64" in diameter which are drilled 2 1/2" from the distal end, to enable
tailpiece 20 to
be pinned into a standard 2" receiver hitch 62 of towing vehicle 64 (see
Figure 7).
Opposing apertures 22 measure 41/64" in diameter and are positioned 8" from
the bottom
of vertically oriented guide 18. Main body 26 of receiver assembly 14 is
constructed of
hollow square tube measuring 31/2"x 31/2", 1/4" in thickness and 10" long.
Socket 28 is
constructed of seamless hollow square tube measuring 2 1/2"x 2 1/2" which
extends
through main body 26 to the back wall and is welded in place. Main body 26 has
opposing apertures 30 measuring 41/64" in diameter which are positioned 2 1/4"
from the
top to allow locking pin 46 to be inserted through both opposing apertures 22
and 30,
thereby locking receiver assembly 14 in the towing position. Aperture 34 of
main body
26 measures 1/2" in diameter and is positioned 3" from the top. Reinforcement
ridge 36
is constructed of a 3/4" long piece of hollow square tube measuring 3"x3",
which is 1/4"
in thickness and welded over the end of socket 28. Mounting plate 40 is a 6"x
4" steel
plate, 1/4 in thickness and is welded to the top of main unit 12. V~inch 38
with a 1400 lb
rating and 3/16" aircraft cable 50 is attached to mounting plate 40 with 3/8"
bolts 42 and
nylock nuts. fable 50 with a thimble and crimped end is attached to receiver
assembly
14 with 1/2" bolt 48 (secured by a flat washer and nylock nut) which extends
through
aperture 34. Vertically oriented guide 18 also includes a further pair of
opposing
apertures (not shown) 16" up from the tow point for other possible uses.
[00019] Referring to Figures 7 and 8, in operation tailpiece 20 of height-
adjustable
trailer hitch 10 is secured to receiver hitch 62 which is rigidly attached to
the rear of
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towing vehicle 64. As previously described in relation to Figures 5 and 6,
cable 50
extending from winch 38 is attached to bolt 48 which is coupled to receiver
assembly 14.
When towed vehicle 64 is being pulled, receiver assembly 14 (with ball hitch
assembly
44 attached thereto) is secured at the lower end of vertically oriented guide
18 with
locking pin 46. When loading or unloading of towed vehicle 64 is desired,
locking pin 46
is removed and winch 48 is engaged using crank handle 41. Tension applied to
cable 50
causes receiver assembly 14 (along with hitch ball assembly 44) to move
vertically along
vertically oriented guide 18. When the desired height is reached by winding
crank handle
41 of winch 38, locking mechanism 39 is engaged. Figure 8 depicts towed
vehicle 66 in a
tilted position which facilitates loading and unloading of a payload (not
shown) by
minimizing the vertical distance over the payload must be moved.
[00020] Although various exemplary embodiments of the invention have been
disclosed,
it should be apparent to those skilled in the art that various changes and
modifications can
be made which will achieve some of the advantages of tl~e invention without
departing
from the true scope of the invention. For example, winch 40 could be
positioned along
the back plate of vertically oriented guide 18 with cable 50 extending over
the top of
vertically oriented guide 18 to facilitate lifting of receiver assembly 14.
Alternately,
tailpiece 20 could be reconfigured for mounting to vehicles not equipped with
a standard
2" receiver hitch. Additionally, hitch ball assembly 44 could be reconfigured
to
accommodate trailers with other coupling mechanisms.
[00021 ] A person understanding this invention may now conceive of alternative
structures and embodiments or variations of the above all of which are
intended to fall
within the scope of the invention as defined in the claims that follow.
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