Note: Descriptions are shown in the official language in which they were submitted.
CA 02168489 2002-08-14
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9 BACKGROUND
Several trailer hitch designs are known that both extend axially and pivot
1 1 horizontally. Such trailer hitches allow a user to back a tow vehicle to a
position where
12 the hitch ball is near the trailer's hitch mechanism and then extend and
pivot the hitch
13 ball so that it is immediately adjacent to the trailer's hitch mechanism.
This allows the
14 user to position the tow vehicle with less accuracy, and saves the time and
labor of
repeated attempts.
16 A typical type of known extendible trailer hitch provides a telescopically
17 extendible arm having the hitch ball attached to the rearward end. The arm
extends
18 radially from a retracted "travel" position within a tubular receiver to an
extended
19 position that is prevented from further extension by some type of keeper or
latch
structure.
21 Similarly, pivot mechanisms are known that allow the user to pivot the
hitch
22 arm so that it may be pointed directly at the trailer's hitch mechanism.
This allows the
23 user to position the hitch ball accurately within a somewhat semicircular
region having
24 a radius of approximately six inches.
2 5 Once the hitch is attached, the user pulls forward with the tow vehicle,
2 6 straightening angle between the tow vehicle's hitch mechanism and the
trailer's hitch
27 mechanism. Structures are known which then change state, thereby preventing
further
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1 pivoting by the pivot mechanism. The user then reverses the tow vehicle,
thereby
2 retracting the extendible arm. The user then activates a locking mechanism
which
3 prevents extension, and retains the arm in the retracted, "travel" position.
4 Unfortunately, the structures known that automatically engage to prevent
S further pivoting generally depend on spring-loaded bolts that snap the bolt
into a hole
6 when that hole pivots into the path of the bolt. Such spring loaded belts
are often not
7 entirely effective. They are prone to freezing, binding, and the degradation
of the spring.
8 As a result, the bolt frequently fails to advance, and the pivoting
mechanism continues to
9 pivot. The user must then, by trial and error, stop the tow vehicle when the
trailer is
straight, and attempt to engage the bolt. Moreover, such bolts tend to be
difficult to
1 1 retract against the bias of the spring. One hand must be used to retract
the bolt, and the
12 other hand must be used to pivot the extendible arm, thereby preventing the
bolt from
13 immediately returning to its locked position. Generally, the bolt is
difficult to retract,
14 since the spring is often over-sized in an attempt to prevent freezing,
binding, and
degradation over time.
16 Another problem facing a driver attempting to hitch a trailer, is that the
trailer
17 hitch is often too high or too low to properly be connected to the trailer
hitch
18 mechanism. This is a failure by the hitch mechanism to compensate for the
height
19 differences between 2- and 4-wheel drive vehicles, cars and trucks, etc.
This can
result in an unbalanced, unsafe driving condition. Moreover, it is frequently
the case
21 that different trailers require a hitch ball at different heights, and a
hitch ball that has
22 been adjusted for a first: trailer might not operate safely with a second
trailer that is
2 3 often towed by the same t:ow vehicle.
24 What is needed is. an adjustably extensible trailer hitch mechanism that
allows a
user to extend an arm supporting a hitch ball in a telescopic manner, and then
to pivot
26 that arm to locate it immediately adjacent to the trailer hitch mechanism.
The hitch
27 mechanism must also allow the user to easily adjust the height of the hitch
ball to
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1 accommodate smaller utility and golf cait trailers, mid-sized boat trailers,
and larger
2 recreational vehicle trailers. The vertical adjustment must also compensate
for the
3 height of the tow vehinle, which can vary from tall 4-wheel drive trucks to
much
4 smaller cars. The hitch mechanism must also provide structures that
automatically
prevent unwanted pivoting of the hitch that are more reliable, simpler, easier
to
6 operate, and less expensive to manufacturer than the presently known
structures.
7
8 SUMMARY
9 The present invention is directed to an apparatus that satisfies the above
needs. A
novel adjustably extensible trailer hitch assembly is provided that extends
radially
1 1 from a retracted "travel" position to an extended position in which the
hitch ball may be
12 positioned adjacent to a trailer's hitch mechanism. A pivot mechanism is
provided that
13 allows the arm supporting the hitch ball to pivot side-to-side in the
horizontal plane so
14 that the hitch ball may be correctly positioned. A U-lock pin is provided,
which
replaces conventional spring-loaded bolt structures, and prevents pivoting
when locked.
16 An adjustable bracket a~embly is provided that allows the hitch ball to be
adjusted
17 vertically, so that tow vehicles and trailers of different heights may be
accommodated.
18 The adjustably extensible trailer hitch assembly of the present invention
19 provides:
( a ) A top plate assembly. The top plate assembly provides a bumper
21 attachment plate having hdes sized to be bolted to the hde pattern
22 found ;as standard equipment in many vehicle bumpers. An extension
23 plate its rearwardly directed and supports a U-lock pin retaining
24 ~ brackevt. A U-shaped bracket is supported by the lower side of the
bumper attachment plate. A vertically oriented pivot bolt is
2 6 supported by centrally located bolt holes in the attachment plate and
2 7 the bottom plate of the U-shaped bracket
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1 ' ( b) A hitch receiver. The hitch receiver is a square
tube having rounded
2 corners that pivots in a horizontal plane on
the vertical pivot bolt
3 within the U-shaped bracket of the top plate
assembly.
4 (c) A hitch extension arm. The hitch extension arm
is incrementally
smaller in cross-section than the hitch receiver,
and slides axially
6 within the hitch receiver. An elongate pivot
bolt opening allows the
7 hitch extension arm to pivot in a horizontal
plane about the pivot bolt.
8 Because the pivot bolt opening is elongate, the
hitch extension arm
9 also is. able to slide axially within the hitch
receiver.
(d) An extension arm end plate. The rearward end
of the extension arm
1 carries; an extension arm end plate that is vertically
1 oriented. The
12 plate provides an array of four bolt holes, typically
consisting of two
13 columns and two rows.
14 (e) A ball mount bracket. A ball mount bracket provides
a vertically
oriented attachment plate and a horizontally
oriented hitch ball
16 support plate. The attachment plate typically
provides eight bolt
17 holes ~amayed in two columns that allow attachment
to the extension
18 arm end plate in four distinct positions. Each
position corresponds to
19 a distiinct elevation of the hitch ball, thereby
permitting vertical
adjustment of the hitch ball support plate and
the hitch ball.
21 ( f ) A U-lock pin, carried by the U-lock pin retaining
bracket of the top
22 plate assembly. The U-lock pin pivots between
an upward position
23 which allows the hitch receiver and hitch extension
arm to pivot, and
24 a lower position that prevents such pivoting
movement. Gravity tends
to bia<.; the U-lock pin to the lower position,
causing the U-lock pin to
26 fall to the lower position when the hitch receiver
and the hitch
27 extension arm are perpendicular to the bumper
attachment plate of
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1 the top plate assembly.
2 ( g) A locking pin. A locking pin prevents axially extending movement by
3 the hitch extension arm within the hitch receiver. The locking pin
4 also prevents rotation of the U-lock pin.
S
6 It is therefore a primary advantage of the present invention to provide a
novel
7 adjustably extensible trailer hitch assembly that allows the user to attach
a trailer
8 hitch to the hitch ball of a tow vehicle more easily, and which prevents
repeated trial-
9 and-error attempts to correctly position the tow vehicle.
Another advantage of the present invention is to provide a novel adjustably
11 extensible trailer hitch assembly that allows a user to adjustably extend
the arm
12 supporting the hitch ball to a position closer to the trailer's hitch
assembly.
13 Another advantage of the present invention is to provide an adjustably
extensible
14 trailer hitch assembly that may be pivoted in the horizontal plane about a
vertical bolt
to better position the hitch ball next to the trailer hitch assembly.
16 Another advantage of the present invention is to provide an adjustably
extensible
17 trailer hitch assembly having a hitch ball that is vertically adjustable to
accommodate
18 trailers having trailer hitch assemblies of various heights, and to
accommodate tow
19 vehicles of different heights, such as two- and four-wheel drive vehicles.
Another advantage of the present invention is to provide an adjustably
extensible
21 trailer hitch assembly having a U-lock pin assembly that allows the hitch
extension arm
22 to pivot when the U-lock pin is in an upper position, but that prevents
pivotal movement
23 when the U-lock pin is in a lower position. The U-lock pin automatically
moves to the
24 lower position when the Bitch extension arm is perpendicular to the top
plate assembly.
2 S A still further advantage of the present invention is to provide an
adjustably
26 extensible trailer hitch assembly having a locking pin that prevents
extension of the
27 adjustable arm when the trailer hitch is in travel position, and that also
prevents the U-
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216~4~9
1 lock pin from moving to a position where rotation is allowed
2 '
DRAWINGS
These and other features" aspects, and advantages of the present invention
will
4 become better understood with regard to the following description, appended
claims, and
accompanying drawings ~rohere:
FIG. 1 is a perspective view of a version of the invention having the hitch
extension arm
retracted fully into the hitch receiver;
8 FIG. 2 is a perspective view of a version of the invention having the hitch
extension arm
9 fully extended;
FIG. 3 is a perspective view of a version of the invention having the hitch
extension arm
1 1 fully extended and rotated to the right;
12 FIG. 4 is a perspective view of a version of the invention having the hitch
extension arm
13 fully extended and rotated to the left;
14 FIG. 5 is a cross-sectional view of the top plate assembly, along the 5-5
lines of FIG. 7;
1 S FIG. 6 is a side view of the top plate assembly;
16 FIG. 7 is a top view of they top plate assembly;
17 FIG. 8 is a side view of the hitch receiver;
18 FIG. 9 is an end view of the hitch receiver;
19 FIG. 10 is a top view of the hitch receiver;
FIG. 11 A is a perspectives view of the hitch extension arm, the extension arm
end plate,
21 and the ball mount bracket showing the hitch ball support plate fully
elevated;
2 2 FIG. 11 B is a perspectives view of the hitch extension arm, the extension
arm end plate,
23 and the ball mount bracket showing the hitch ball support plate partly
elevated;
24 FIG. 11C is a perspective view of'the hitch extension arm, the extension
arm end plate,
and the ball mount bracket showing the hitch ball support plate partly
lowered;
26 FIG. 11 D is a perspective view of the hitch extension amp, the extension
arm end plate,
~ and the ball mount bracket showing the hitch ball support plate fully
lowered;
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i FIG. 12 is a side view of the hitch extension arm, the extension arm end
plate, and the
2 ball mount bracket;
3 FIG. 13 is an end view of the hitch extension arm, the extension arm end
plate, and the
4 ball mount bracket;
FIG. 14 is a top view of the hitch extension arm, the extension arm end plate,
and the
6 ball mount bracket; and
7 FIG. 15 is an end view of the extension arm end plate with the ball mount
bracket
8 removed.
9
DESCRIPTION
1 1 Referring in particular to FIG. 1, an adjustably extensible trailer hitch
12 assembly 10 constructed in accordance with the principles of the invention
is seen. The
13 trailer hitch provides a top plate assembly 20 that attaches to the bolt
pattern that is
14 standard on most bumpers. The l:op plate assembly 20 pivotably carries a
hitch receiver
60 that is pivotably in a horizontal plane about a vertical pivot bolt 190. A
hitch
16 extension arm 90 is carried within the hitch receiver 60, and telescopes
axially
17 between a retracted "travel position" and an extended position that may be
adjusted to
18 position the hitch ball immediately adjacent to the hitch of a trailer to
be towed. An
19 extension arm end plate 110 having a plurality of bolt holes is carried by
the end of the
extension arm 90. A ball mount bracket 130 having a matrix of bolt holes is
attachable
21 to the extension arm end plate in a variety of manners, each corresponding
to a different
22 hitch ball elevation. A U-lock pin 150, carried by the top plate assembly
20 is
2 3 manually moved to an upper position that allows the hitch receiver 60 and
the hitch
24 extension arm 90 to pivot. After attaching the trailer, the driver pulls
forward a short
2 S distance, which allows the hitch receiver to straighten, causing the U-
lock pin 150 to
2 6 fall due to gravity to a lower position, which prevents pivoting by the
hitch receiver.
27 Reversing the direction of the tow vehicle for a short distance causes the
extension arm
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1 90 to retract into the hitch receiver 60, thereby returning the hitch to the
travel
2 position. The hitch extension arm 90 may then be locked to the hitch
receiver 60 ~to
3 prevent axial movement by means of a locking bolt 170. Locking bolt 170 also
prevents
4 movement of the U-lock pin into the upper position.
The top plate asr~embly 20 provides a bumper attachment plate 21 having a left
6 bolt hole 22, a right Ibolt hole 23, and a pivot bolt hole 24. In the
preferred
7 embodiment, the bumper attachnnent plate 21 is 4 inches by 11 inches, and is
made of
8 3/8 inch thick steel plate. An upper surface 25 and a lower surface 26 are
seen in FIG.
9 5. The pivot bolt hole 24 is 3/4 inch in diameter, and is centrally located.
The left and
right bolt holes 22, 23 are 5/8 inch in diameter, and have centers that are
located 1.5
11 inches from the mid-points of the 4 inch sides.
12 An extension platy 27 is 2.5 inches wide and extends 3 inches outwardly
from the
13 center of attachment plate 21, as seen in FIG. 7. The extension plate
provides a right
14 edge 28, a left edge 29, and a rear edge 30. An upper surface 31 and a
lower surface 32
are seen in FIG. 6.
16 A U-lock pin retaining bracket 33 is seen in FIGS. 1 and 6. The retaining
17 bracket 33 is saddle shaped, and provides a forward edge 34 and a rearward
edge 35. A
18 left end opening 36 and .a right end opening 37 allow the U-lock pin 150 to
protrude, as
19 will be seen. A channel 38 extends between the openings 36, 37. In the
preferred
embodiment, the retaining bracket 33 is made of a curved piece of steel plate
having a .
21 height of 1 inch and a length of .?.5 inches, and a thickness of 1 /8 inch.
The retaining
22 bracket 33 is typically attached to the upper scxface 31 of the extension
plate 27 by
2 3 welding.
24 A U-shaped bracket 39 is carried by the lower surface 26 of the bumper
2 5 attachment plate 21. The U-shaped bracket 39 is formed from a sheet of
steel that is
26 approximately 12 inches by 4 inches and 3/8 inch thick. Left and right
bends 44, 45
27 cause the sheet of steel to assume U-shaped appearance. A left upper edge
40 and a right
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1 upper edge 41 are welded to the lower surface 26 of plate 21. Vertically
'oriented left
2 and right sides 42, 43 support a bottom plate 46. As seen in FIG. 5, the
bottom plate 46
3 provides an upper surface 47 that supports the hitch receiver 60, and an
oppositely
4 directed tower surface 48. The distance from the upper surface 47 of the
bottom plate
46 of the U-shaped bracket 39 to the lower surface 26 of the bumper attachment
plate
6 21 is typically about 2 5/8 inches. A pivot bolt hole 49 is centrally
located, and is
7 typically 3/4 inch in sizes to correspond with the upper pivot bolt hole 24
in the bumper
8 attachment plate 21. Left and right safety chain holes 50 and 51 allow the
user to attach
9 the standard S-hook or similar type of safety chain attachment structures.
The pivot bolt 190 is carried by the pivot bolt hole 24 in the bumper
attachment
1 1 plate 21 of the top plate assembly 20 and also pivot bolt hole 49 in the
bottom plate 46
12 of the U-gaped bracket 39 of the top plate assembly 20. The pivot bolt 190
is typically
13 a 3/4 inch bolt, and allows both the hitch receiver 60 and the hitch
extension arm 90 to
14 pivot in a horizontal plate about the bolt.
1 S A hitch receiver 60 having a tube-like body 61 and a collar 72 is
pivotally
16 carried by the pivot bolt 190 in the top plate assembly 20. The body 61
provides an
17 open forward end 62 and an open rearward end 63. The body 61 is hollow, and
a channel
18 71 runs the length of they body. The body has an upper surface 64 having a
hole 65 for
19 the pivot bolt 190 and a tower surface 66 having a similar pivot bolt hole
67. Side
surfaces 68 have holes 69 which carry the locking bolt 170. The collar
provides an
21 outer surface 73, a forward surface 74, and a rearward surface 75, as seen
in FIG. 10.
22 In the preferred embodiment, the body 61 of the hitch receiver is made of
square
23 tubing having rounded cixners 70 and 2.5 inch sides. The length of the body
61 is 8
24 inches. The upper and lower pivot bolt holes 65, 67 are 3/4 inches in
diameter and
2 S have centers 2 inches from the forward end 62. The left and right locking
pin holes 69
26 are 5/8 inches in diameter and have centers 2.5 inches from the rearward
end 63. The
27 collar 72 is formed from a 10 inch long, 5/8 inch wide piece of 5/16 inch
thick steel
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1 that is wrapped hot around the rearward 63 of the body 61 and welded into
place.
2 The hitch extension arm 90 is pivotally carried by the pivot bolt 190, and
is
3 slidably carried inside the hitch receiver 60. The hitch extension arm 90 is
formed of
4 square steel tubing having rounded corners 94. A forward end 91 is open,
while a
similar rearward end 92 is attached to the extension arm end plate 110. An
interior
6 channel 93 runs the length of the tube. The upper surface 95 and the lower
surface 97
7 provides similar elongates pivot bolt openings 96, 98 that allow the
extension arm to
8 pivot about the pivot bolt 190. The elongate nature of the pivot bolt
openings 96, 98
9 allow the extension arm 90 to slide within the hitch receiver 60. The side
surfaces 99
each have a locking pin hole 100 which is sized to match the locking bolt 170.
11 In the preferred embodiment, the hitch extension arm is 15 inches long, and
is
12 made from square 1 /4 inch thick tubing having 2 inch sides and rounded
comers. The
13 elongate pivot bolt openings 96, 98 are typically about 7 inches long, to
allow the hitch
14 extension arm 90 to travel 7 inches within the hitch receiver. Locking pin
holes 100
are typically 5/8 inch in diameter, and have centers that are 3.5 inches from
the
16 rearward end 92 of the arm 90. When the extension arm is perpendicular to
the
17 bumper attachment plate. 21, and fully extended, pivoting the extension arm
will rotate
18 the hitch ball through a distance of approximately 8 inches to either the
left or right.
19 This distance is primarily a function of the length of the arm 90 and the
dimensions of
the top plate assembly 2Ci.
21 The extension arrn end plate 110 is attached to the rearvvard end 92 of the
hitch
22 extension arm 90 by means of welded connection. The end plate 110 provides
a forward
23 surface 112, a rearward surface 'I 13, and a perimeter surface 114, as seen
in FIGS. 11
24 - 15. y A matrix of adjustment holes 115 is provided, typically arrayed in
a left column
2 5 116 and a right column 117.
26 In the preferred embodiment, the extension arm end plate 110 is 5 inches
27 horizontally and approximately 4.25 inches vertically, as seen in FIGS. 12
and 13.
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' 1 Eight adjustment holes 'I 15 are typically provided, each suitable for 3/8
or 1 /2 inch
2 bolts.
3 The ball mount bracket 130 is fastened to the extension arm end plate 110 by
4 means of fastening hardavare 1 18, typically including 3/8 or 1 /2 inch
diameter bolts or
other suitable fastener. The ball mount bracket 130 provides a vertically
oriented
6 attachment plate 131 and a horizontally oriented hitch ball support plate
138, separated
7 by a rounded 90 degree lr~end 137, as seen in FIG. 1 1.
8 The attachment plate 131 provides an end edge 132 and left and right side
edges
9 133. A matrix of adjustnnent holes 134 sized and arranged to complement the
matrix of
holes 115 on the extension arm end plate 110 is provided, typically arrayed in
a first
1 1 column 135 and a second column 136. The ball mount bracket 130 may be
oriented with
12 the hitch ball support plate 138 located above attachment plate 131, as
seen in FIGS.
13 11 A and 11 B. Alternatively, the ball mount bracket 130 may be oriented
with the hitch
14 ball support plate 138 lo~:ated below the attachment plate 131, as seen in
FIG. 11 C and
11 D. In practice, this usually means that the extension arm 90, the extension
arm end
16 plate 110, and the ball mount bracket 130 are removed as a unit from the
hitch
17 receiver 60 after removing the pivot bolt 190 and replaced after a 180
degree rotation.
18 The hitch ball is then installed in the proper orientation.
19 The hitch ball support plate 138 provides a hitch ball bolt hole 139 which
will
rigidly support any type ~of hitch ball, typically from 1 7/8 inch to 2.5
inch, although a
21 2 inch hitch ball is standard.
22 In the preferred embodiment, the ball mount bracket 130 is formed of steel
plate
23 having a width of 5 inches and length prior to the formation of bend 137 of
24 approximately 8.5 inches.. After bend 137 is made, the attachment plate 131
has a
height of approximately 4.5 inches and the hitch ball support plate extends
26 approximately 4 inches from the extension arm end plate 110.
27 A U-lock pin 150 is carried by the U-lock pin retaining bracket 33 of the
top
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1 plate assembly 20. The U-lock pin is rotatable from an upper position, seen
in FIG. 3,
2 to a lower position, seen in FIG. 1. In the lower position, where the pin
150 is biased by
3 gravity, the hitch receivE~r 60 is prevented from pivoting on the pivot bolt
190. When
4 the U-lock pin is held in the upper position, a user may pivot the hitch
receiver about
the pivot bolt. Once the hitch receiver is pivoted, the upper surface 64 of
the hitch
6 receiver supports the U-lock pin, as long as the hitch receiver is not
perpendicular to
7 the long side of the bunnper attachment plate Z 1. As seen in FIG. 1, when
the hitch
8 receiver 60 is perpendicular to the bumper attachment plate, the U-lock pin
falls to the
9 lower position, preventirna the hitch receiver from pivoting. As seen in
FIG. 3, when the
hitch receiver is not perpendicular to the attachment plate, the U-lock pin is
in the
1 1 raised position, supported by the hitch receiver. As seen by a comparison
of FIGS. 1 and
12 3, the U-lock pin 150 rotates freely in bracket 33. A middle section 151 is
13 approximately the length of the rear edge 30 of the extension plate 27.
Left and right
14 bends 153, 155 and associated left and right segments 152, 154 are seen in
FIGS. 5 and
6.
16 In the preferred embodiment, the middle section 151 is approximately 2.5
17 inches in length. Left ;and right segments 152, 154 are approximately 2
inches in
18 length, and the the U-lock pin is approximately 5/8 inch in diameter.
19 The locking bolt '170 is carried by the locking pin holes 69 in the hitch
receiver
60 and by the locking pin holes 100 in the side surfaces 99 of the hitch
extension arm
21 90. When the locking bolt 170 is inserted through these holes, movement of
the hitch
22 extension arm 90 relative to the hitch receiver 60 is prevented. However,
when the
23 locking bolt 170 is removed, the hitch extension arm 90 may move axially
within the
24 hitch receiver 60 a distance equal to the length of the elongate pivot bolt
openings 96,
2 5 98 in the hitch extension arm. Additionally, when the locking bolt 170 is
inserted, the
26 U-lock pin 150 is prevented from rotating out of is lower position, where
pivoting of
27 the hitch receiver is prevented.
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1 The locking bolt 170 provides a straight body 171, a bent end 172, and a
tapered
2 point 173. The tapered point is adjacent to a pin hole 175 used to secure
locking pin
3 180. An optional annular recess 174 prevents unwanted movement of the
locking pin
4 180. The bent end 17i'. is bent to prevent its passage into the holes 69,
100. The
tapered point 173 allows easier insertion of the bolt 170 into holes 69, 100.
6 In the preferred embodiment, the locking bolt 170 is typically 5 to 6 inches
in
7 length and 5/8 inches in diameter. The straight body 171 is approximately
3.5 inches
8 long, while the bend end 172 is approximately 2 inches long.
9 As seen in FIG. 1, the locking pin 180 is inserted into the hole 175, and
prevents
the locking bolt 170 from falling out due to vibration during travel.
1 1 Prior to use, the user should adjust the elevation of the hitch ball bolt
hole 139
12 to the appropriate level. This may be done by releasing the fasteners 118
holding the
13 extension arm end plate 110 to the ball mount bracket 130 and repositioning
the ball
14 mount bracket. In some instances, it is easier to release the pivot bolt
190, and rotate
the hitch extension arm 90 by 180 degrees. Therefore, it can be seen that the
left
16 column of adjustment holes 116 may be attached to either the first or
second column of
17 adjustment holes 134, 1 36 of the ball mount bracket 130, depending on the
need. As a
18 result, the right column of adjustment holes 117 will be attached to either
the second or
19 first column of adjustment holes 136, 134. The hitch ball must then be
installed right
side up. .
21' To use the adjustably extensible trailer hitch of the invention, the user
should
22 back a tow vehicle into tlhe area of a trailer to be towed. Due to the
capabilities of the
23 trailer hitch disclosed, it: is not necessary that the hitch ball of the
tow vehicle be
24 positioned exactly. The ~,rser then removes the locking pin 180 and the
locking bolt 170.
2 5 This allows the hitch extension arm to be extended, as needed. The user
then lifts the U-
26 lock pin to a 90 decree or greater angle, as seen in FIG. 3, and pivots and
extends the
27 hitch receiver 60 and hitch extension arm 90 as required to positioned the
hitch ball as
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1 near to the trailer's hitch mechanism as possible. The trailer hitch is then
attached to
2 the hitch ball of the tow vehicle's hitch assembly. If they will reach, the
safety chains
3 are then attached to the safety chain holes 50, 51. The user then drives
forward a short
4 distance. This movement causes the hitch extension arm 90 to become
perpendicular
with the bumper attachment plate 21, which allows gravity to lower the U-lock
pin 150
6 to its lower position, thus preventing further pivoting. The user then may
put blocks
7 behind the trailer's wheels, if desired, and back the tow vehicle so that
the extension
8 arm 90 is retracted fully into the hitch receiver 60. At this point the
locking pin holes
9 69 and 100 are aligned, and the locking bolt 170 and locking pin 180 may be
installed.
If not already done, the safety chains should be attached. The trailer hitch
is now in the
11 travel position.
12 The previously described versions of the present invention have many
13 advantages, including a novel adjustably extensible trailer hitch assembly
that allows
14 the user to attach a trailer hitch t:o the hitch ball of a tow vehicle more
easily, and which
prevents repeated trial-and-error attempts to correctly position the tow
vehicle.
16 Another advantage of the present invention is to provide a novel adjustably
17 extensible trailer hitch assembly that allows a user to adjustably extend
the arm
18 supporting the hitch ball to better position the hitch ball next to the
trailer hitch
19 assembly.
Another advantage of the present invention is to provide an adjustably
extensible
21 trailer hitch assembly that may be pivoted about a vertical bolt to better
position the
22 hitch ball next to the trailer hitch assembly.
23 Another advantage of the present invention is to provide an adjustably
extensible
24 trailer hitch assembly having a hitch ball that is vertically adjustable to
accommodate
trailers having trailer hitch assemblies of various heights, and to
accommodate tow
26 vehicles of different heights, such as two- and four wheel drive vehicles.
27 Another advantage of the present invention is to provide an adjustably
extensible
14
CA 02168489 2002-08-14
1 trailer hitch assembly having a U-lock pin assembly that allows the hitch
extension arm
2 to pivot when the U-lock pin is in an upper position, and where the U-lock
pin moves
:3 automatically by means of gravity to a lower position that prevents pivotal
movement.
4 A still further advantage of the present invention is to provide an
adjustably
!p extensible trailer hitch assembly having a locking pin that prevents
extension of the
G adjustable arm when the trailer hitch is in travel position, and that also
prevents the U-
7 lock pin from moving to a position where rotation is allowed.
8
~) Although the present invention has been described in considerable detail
and with
reference to certain preferred versions, other versions are possible. For
example,
1 ) while the dimensions of the components of the preferred embodiment have
been
12 disclosed, variations in the dimensions are possible, while staying within
the scope and
1 a teachings of the invention. Also, while the bolt patterns disclosed on the
hitch extension
14 arm end plate and the ball mount bracket are preferred, a variety of other
bolt patterns
would be possible. further, the use of bolts to attach the extension arm end
plate to the
16 ball mount bracket is not required, and other fasteners may be substituted.
Therefore,
17 the spirit and scope of the appended claims should not be limited to the
description of the
18 preferred versions disclosed here.
19
27
22
23
24
26
27
