Tow bar apparatus

CROSS-REFERENCE TO RELATED APPLICATIONS

This application for a utility patent is a continuation-in-part of a previously filed utility patent, now abandoned, having the application Ser. No. 09/302,543, filed Apr. 30, 1999.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to tow bars, and more particularly to a tow bar apparatus that allows the towed vehicle a great range of motion relative to the towing vehicle white still providing a strong connection between the two vehicles.

2. Description of Related Art

Tow bars that bolt directly onto a towing vehicle for towing a towed vehicle also well known in the prior art. Examples of such tow bars are shown in Parent, U.S. Pat. No. 5,765,851, and Johnson, U.S. RE Pat. No. 35,482, which are described in greater detail below. While these tow bars are superior to a ball hitch, these tow bars are both bulky and relatively expensive to manufacture. To provide the flexibility necessary to allow the towed vehicle a range of motion relative to the towing vehicle, most prior art tow bars include three hinged connections, one hinge providing flexibility in the horizontal plane, a second hinge providing flexibility in the vertical plane, and a third hinge that provides a pivotal point for twisting. While these hinges are functional, they are also weak points in the tow bar that could break under rigorous conditions.

It is also known to substitute at least one of the hinged connections with a ball-and-socket connection. Examples of this are shown in R. E. Moore, U.S. Pat. No. 2,139,970 and J. E. Powell, U.S. Pat. No. 1,185,435. Moore teaches a tow bar that uses three ball-and-socket connections similar to the present invention; however, Moore does not teach ball-and-socket connections that are similar to the present invention. In Moore, the ball-and-socket connections are designed to be permanent, and the sockets are removably attachable to the vehicles. This is not a structurally reliable configuration. The novel ball-and-socket connections disclosed in the present invention enable the tow bar to be even stronger and more reliable than prior art tow bars, and yet still easily removable when not in use.

Powell teaches a similar tow bar that only uses a single ball-and-socket connection. Powell suffers from the same disadvantages as Moore, and does not provide the strength required in combination with the easy disconnection of the ball-and-socket connection. W. W. Cushman, U.S. Pat. No. 2,916,301, teaches warehouse tractors and the like and has for its primary object to so modify the pusher plate on such vehicles that the latter may be readily connected together as a train and be pulled to and from the place of work by a leading vehicle. While Cushman teaches the use of a pair of bars that terminate in hemispheres that can be joined to form a single unit, the hemispheres of Cushman are not positioned within a ball-and socket connection. In Cushman, the hemispheres are part of a jack mechanism that merely push against a half-socket for the purposes of depressing the drawbar tongue and raising the tractor. Cushman does not teach the combination of two hemispheres within a complete socket to form a ball-and-socket connection that can withstand both pushing and pulling forces.

W. La Hodny, U.S. Pat. No. 2,071,883, teaches a ball-and-socket connection that is somewhat similar to the present invention; however, this reference is in the field of rear view mirrors. To the extend Hodney is instructive of the present invention, it would not be obvious to apply the teachings of this field to the field of towing vehicles. Rear view mirrors must be adjustable in all three dimensions, but they do not have to be very strong. Designs that might be highly adjustable, and functional for rear view mirrors, would not often be capable of withstand the rigorous pushing and pulling strains that are placed on a tow bar apparatus.

Parent, U.S. Pat. No. 5,765,851, teaches a storable self-aligning towing assembly which allows universal pivoting about three axes between a towing vehicle and a towed vehicle. The towing assembly is self-supporting. A hitching member is releasably attached to a towing vehicle at a first end of the hitching member; a first yoke member is pivotally attached to a second end of the hitching member such that the first yoke member pivots about a first axis which is generally horizontal and is normal an extended longitudinal axis of the hitching member; a second yoke member is connected to the first yoke member such that the second yoke member is free to rotate with respect to the first yoke member about an axis that is generally parallel to an extended longitudinal axis of the hitching member; a towed vehicle attachment means is releasably attached at a first end to a towed vehicle; the towed vehicle attachment means is pivotally attached to the second yoke member such that the second yoke member pivots with respect to the towed vehicle attachment means about a second axis which is generally vertical axis and is normal to the extended longitudinal axis of the hitching member. The configuration allows the towing assembly to pivot from a towing position to a storage position on the rear of the towing vehicle. A latching mechanism secures the self-aligning towing assembly in the storage position on the rear of the towing vehicle. The self-aligning towing assembly may be further converted into a shipping position.

Johnson, U.S. Re. Pat. No. 35,482, teaches a towing hitch including a frame having a forward portion selectively connected to the receiver hitch of a towing vehicle, and a rearward portion having a pair of elongated bars pivotally connected thereto for removable connection to a vehicle to be towed. Each bar has a pivot arm connected to the rearward end thereof, said pivot arms and bars all to the rearward end thereof, said pivot arms and bars all pivotal within a single plane, so that the pivot arms may be folded into a storage position adjacent and parallel to the bars. Selective locking apparatus permits the pivot arms to be extended to a towing position aligned with the bars and locked in the towing position. The bars are pivotally connected to a pivot block which is pivotally mounted to the forward portion of the frame, so as to permit the pivot block, and attached bars and arms to pivot from a generally horizontal position to a generally vertical storage position. The pivot block is mounted on a rotatable yoke, such that the bars and pivot arms are rotatable, as a unit, along an axis parallel to the direction which a vehicle is being towed.

Hobrath, U.S. Pat. No. 5,909,887, teaches a sulky for a self propelled lawn mower, the sulky being interconnected by a pivot frame and a horizontal pivot to the mower frame, and a vertical pivot between the sulky frame and wheels in order to retain the operator in a constant position in respect to the mower under all operator conditions.

The prior art teaches tow bars with flexibility between the towed and towing vehicle. However, the prior art does not teach a tow bar having three ball-and-socket connections that allow a towed vehicle a great range of motion relative to the towing vehicle, while still providing a strong connection that will not break even under rigorous towing and braking conditions. The prior art does not teach the use of two hemispheres that join within a socket to form a ball-and-socket connection. The prior art also does not teach a pair of socket members that enable a removable ball-and-socket connection between the tow bar and the towed vehicle. The present invention fulfills these needs and provides further related advantages as described in the following summary.

SUMMARY OF THE INVENTION

The present invention teaches certain benefits in construction and use which give rise to the objectives described below.

The present invention provides a tow bar apparatus that allows a towing vehicle to tow a towed vehicle. The tow bar apparatus includes a hitch member, a pair of tow bars, and a pair of socket members. The hitch member is adapted to engage a tow bar receiver of the towing vehicle. The pair of socket members are adapted to be attached to the towed vehicle. Each of the pair of tow bars includes a plate ball member at a first end for pivotally engaging one of the pair of socket members. Each of the pair of tow bars further includes a second end, the second ends of the pair of tow bars being joined to form a hitch ball member that pivotably and rotatably engages the hitch member.

A primary objective of the present invention is to provide a tow bar apparatus having advantages not taught by the prior art.

Another objective is to provide a tow bar apparatus that allows the towed vehicle a great range of motion relative to the towing vehicle, without weakening the strength of the tow bar.

A further objective is to provide a tow bar apparatus that includes a pair of tow bars, each of the pair of tow bars having a hemisphere at a second end, the two hemispheres being joined within a hitch socket member to form a ball-and-socket connection.

A further objective is to provide a tow bar apparatus that includes a pair of socket members that enable a removable ball-and-socket connection between the tow bar and the towed vehicle.

Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings illustrate the present invention. In such drawings:

FIG. 1

is a perspective view of the preferred embodiment of the present invention;

FIG. 2

is an exploded perspective view of a pair of tow bars;

FIG. 3

is a sectional view thereof taken along line

3

—

3

in

FIG. 1

, showing a hitch member in phantom after it has pivoted vertically with respect to the tow bar;

FIG. 4

is a sectional view thereof taken along line

3

—

3

in

FIG. 1

, showing the hitch member and the tow bar in phantom after they have pivoted vertically with respect to a plate socket member;

FIG. 5

is a top plan view of the invention showing the hitch member in phantom after it has pivoted horizontally with respect to the tow bar;

FIG. 6

is a perspective, partially exploded view of a tow plate having a pair of socket members, each of the pair of socket members including a top bearing element and a bottom bearing element;

FIG. 7

is a perspective view of a first alternative embodiment of one of the pair of tow bars,

FIG. 8

is a perspective view of a second alternative embodiment of one of the pair of tow bars,

FIG. 9

is a front perspective view of an alternative embodiment of the hitch member; and

FIG. 10

is an exploded rear perspective view thereof.

DETAILED DESCRIPTION OF THE INVENTION

The above-described drawing figures illustrate the invention, a tow bar apparatus

10

for use by a towing vehicle

12

to tow a towed vehicle

16

. As shown in

FIG. 1

, the tow bar apparatus

10

includes a hitch member

20

, a pair of socket members

60

, and a pair of tow bars

110

. The hitch member

20

is adapted to engage a tow bar receiver

14

of the towing vehicle

12

. The pair of socket members

60

is adapted to be attached to the towed vehicle

16

. Each of the pair of tow bars

110

includes a plate ball member

114

at a first end

112

for pivotally engaging one of the pair of socket members

60

. Each of the pair of tow bars

110

further includes a second end

116

, the second ends

116

of the pair of tow bars

110

being joined to form a hitch ball member

120

that pivotably and rotatably engages the hitch member

20

.

Hitch Member

As shown in

FIG. 1

, the hitch member

20

includes a hitching portion

22

and a hitch socket member

24

. The hitching portion

22

is shaped to slidably engage a tow bar receiver

14

of the towing vehicle

12

so that a hitch locking bolt (not shown) can be used to lock the hitching portion

22

to the tow bar receiver

14

of the towing vehicle

12

. This hitching mechanism is well known in the art, and is disclosed in greater detail in Johnson, U.S. Re. 35,482, and Parent, U.S. Pat. No. 5,765,851, hereby incorporated by reference. While the hitching portion

22

illustrated in

FIG. 1

is the preferred embodiment, those skilled in the art can modify the hitching portion

22

to connect the hitch member

20

to the towing vehicle

12

in a variety of ways, including but not limited to the following: a trailer-hitch shape to connect to a ball hitch, well known in the prior art; a locking mechanism as shown in Moore, U.S. Pat. No. 2,139,970, and Hawkins, U.S. Pat. No. 3,000,652, hereby incorporated by reference; and directly connecting the hitch ember

20

to the towing vehicle

12

by welding, bolting, or equivalent means. It is preferred, however, that the hitch member

20

be readily removable from the towing vehicle

12

so that he tow bar apparatus

10

can readily be removed from the towing vehicle

12

when not in use.

Hitch Socket Member

As shown in

FIG. 1

, the hitch socket member

24

is shaped to form a ball-and-socket relationship with the second end

116

of each of the pair of tow bars

110

, as described in greater detail below. As shown in

FIG. 3

, to enable this relationship the hitch socket member

24

includes a hitch socket peripheral lip

26

that defines a hitch socket central aperture

28

that communicates with a hitch socket internal chamber

30

of the hitch socket member

24

. As shown in

FIGS. 3-5

, the hitch socket member

24

allows the hitch ball member

120

a wide range of motion in yaw, pitch, and roll axes.

In a first embodiment, as shown in

FIG. 1

, the hitch socket member

24

is formed in two steel parts that are welded, bolted, or otherwise fastened together around the hitch ball member

120

. In this embodiment, the hitch socket member

24

functions to contain the hitch ball member

120

, so it is important that the hitch socket central aperture

28

be smaller than the hitch ball member

120

. The hitch ball member

120

is inserted into the hitch socket internal chamber

30

during the manufacture of the hitch socket member

24

. It is preferred that a plastic component be included to prevent metal-to-metal contact within the connection.

Either the hitch socket member

24

or the hitch ball member

120

can be constructed of high strength plastic, or a separate insert can be used, as described below.

In a second embodiment, as. shown in

FIGS. 9 and 10

, the hitch socket member

24

further includes a hitch socket top aperture

32

, a top socket bearing element

34

, and a bottom socket bearing element

36

. The top and bottom socket bearing elements

34

and

36

perform the function of contacting and containing the hitch ball member

120

, so it is possible for the hitch socket central aperture

28

to be larger than the hitch ball member

120

. The top and bottom socket bearing elements

34

and

36

are inserted into the hitch socket internal chamber

30

through the hitch socket top aperture

32

, as described below.

The top and bottom socket bearing elements

34

and

36

have top and bottom hitch socket outside surfaces

38

and

39

, respectively, together shaped to fit within the hitch socket internal chamber

30

of the hitch socket member

24

. The top and bottom socket bearing elements

34

and

36

further have top and bottom hitch socket inside bearing surfaces

40

and

41

, respectively, that are together shaped to provide a bearing surface around at least part of a hitch ball member

120

. The top and bottom hitch socket inside bearing surfaces

40

and

41

are preferably concave and extend around enough of the hitch ball member

120

far enough to securely lock the hitch ball member

120

within the hitch socket member

24

with enough strength to withstand the rigors of towing. The top and bottom socket bearing elements

34

and

36

preferably further provide top and bottom socket bearing slots

42

and

43

, respectively, that together enable each of the pair of tow bars

110

, but not the hitch ball member

120

, to escape from within the hitch socket internal chamber

30

.

As shown in

FIG. 10

, the bottom socket bearing element

36

is first inserted into the hitch socket internal chamber

30

through the hitch socket top aperture

32

, the bottom socket bearing element

36

resting upon a bottom surface

58

of the hitch socket member

24

. The hitch ball member

120

is inserted through the hitch socket central aperture

28

and into the hitch socket internal chamber

30

, the hitch ball member

120

being positioned on the bottom hitch socket inside bearing surface

41

. The top socket bearing element

34

is then inserted into the hitch socket internal chamber

30

through the hitch socket top aperture

32

, the top socket bearing element

34

being positioned on top of the hitch ball member

120

such that the top hitch socket inside bearing surface

40

contacts and contains the hitch ball member

120

.

Finally, a locking plate

50

is positioned over the hitch socket top aperture

32

to lock the hitch ball member

120

and the top and bottom socket bearing elements

34

and

36

in place. The locking plate is preferably a steel disk shaped to fit within the hitch socket top aperture

32

where it is locked in place with a plurality of locking bolts

52

. Various alternative embodiments, of course, can be devised. The embodiments used on the pair of socket members

60

, such as the cap portion

80

, are illustrative of various embodiments that may be employed and which should be considered equivalent to the present invention.

In the preferred embodiment, the locking plate

50

includes a means for compressing the top and bottom socket bearing elements

34

and

36

against the hitch ball member

120

. The means for compressing is preferably an adjustable compression plate

54

positioned between the locking plate

50

and the top socket bearing element

34

. An adjustment bolt

56

is preferably positioned through, and threadedly engaged with, an adjustment bolt aperture

57

of the locking plate

50

, such that the adjustment bolt

56

depresses the compression plate

54

when tightened.

It is, of course, equivalent to reverse the location of the compression plate

54

within the hitch socket member

24

, such that the compression plate

54

is located between the bottom surface

58

and the bottom socket bearing element

36

. Those skilled in the art can also devise countless equivalent screws, levers, and other mechanisms to compress the top and bottom socket bearing elements

34

and

36

against the hitch ball member

120

as described herein, and these alternative embodiments should be considered within the scope of the described claims.

In the second embodiment of the hitch socket member

24

, the preferred embodiment, the hitch socket central aperture

28

must be larger than the hitch ball member

120

to allow the insertion described above. In this embodiment, the top and bottom socket bearing elements

34

and

36

must contain the hitch ball member

120

.

In a third embodiment of the hitch socket member

24

(not shown), the hitch ball member

120

is inserted into the hitch socket internal chamber

30

through the hitch socket top aperture

32

.

This embodiment is similar to the pair of socket elements

60

described below. In this embodiment, the hitch socket top aperture

32

must communicate with the hitch socket central aperture

28

to enable insertion. The benefit of this embodiment is that the hitch socket central aperture

28

can be smaller than the hitch ball member

120

, so that the hitch socket member

24

functions to assure that the hitch ball member

120

does not escape through the hitch socket central aperture

28

.

Pair of Tow Bars

As shown in

FIG. 1

, the tow bar apparatus

10

includes a pair of tow bars

110

for connecting the hitch member

20

to the pair of socket members

60

. In a first embodiment, as shown in

FIG. 2

, each of the pair of tow bars

110

is an elongate bar having a first end

112

and a second end

116

. The pair of tow bars

110

must be rigid and strong enough to withstand the rigors of towing. The pair of tow bars

110

are preferably constructed of steel or similar high-strength material.

As shown in

FIG. 2

, the first end

112

of each of the pair of tow bars

110

has a plate ball member

114

, preferably a steel ball such as is commonly used in ball-and-socket joints. In an alternative embodiment, however, the plate ball member

114

might be constructed of hard plastic, in which case the top and bottom bearing elements

90

and

92

are not required. In yet another alternative embodiment, however, the first end

112

might have another mechanism for attaching the pair of tow bars

110

to the towed vehicle

16

, the mechanisms including any of the mechanisms shown in the prior art listed above and incorporated by reference.

The second ends

116

of the pair of tow bars

110

are joined together to form a hitch ball member

120

. The hitch ball member

120

is shaped to be pivotally and rotatably engaged within the hitch socket internal chamber

30

of the hitch socket member

24

such that each of the pair of tow bars

110

extends out of the hitch socket internal chamber

30

through the hitch socket central aperture

28

but the hitch ball member

120

is locked within the hitch socket internal chamber

30

by either the hitch socket peripheral lip

26

or the top and bottom socket bearing elements

34

and

36

.

The second end

116

of each of the pair of tow bars

110

preferably includes a hemisphere

118

, the hemispheres

118

of the pair of tow bars

110

interlocking to form the hitch ball member

120

. The hitch ball member

120

is preferably pivotally and rotatably engaged between the top and bottom socket bearing elements

34

and

36

within the hitch socket internal chamber

30

, as described above, such that each of the pair of tow bars

110

extends through the hitch socket central aperture

28

. While it is preferred that the pair of tow bars

110

each include a hemisphere

118

that is half of a sphere, for purposes of this application this term includes the various alternative shapes that together form a generally round hitch ball member

120

that is capable of forming a functional ball and socket connection with the hitch socket member

24

.

As shown in

FIGS. 2-5

, the hitch ball member

120

preferably further includes a pivot pin

122

that pivotally locks the two hemispheres

118

together. This construction allows the pair of tow bars

110

to pivot with respect to each other, thereby enabling the tow bar apparatus

10

to collapse when not in use for easier storage, and then fold back open for use. The pivot pin

122

also prevents the two hemispheres

118

from sliding against each other and potentially enabling the hitch ball member

120

to escape from the hitch socket member

24

.

Pair of Socket Members

The first end of each of the pair of tow bars

110

includes a means for removably engaging the first end

112

of each of the pair of tow bars

110

to the towed vehicle

16

. As shown in

FIG. 1

, the means for removably engaging is preferably the pair of socket members

60

. Each of the pair of socket members

60

is adapted to be attached to the towed vehicle

16

for providing an attachment point for the pair of tow bars

110

to the towed vehicle

16

.

As shown in FIGS.

1

and

3

-

5

, each of the pair of socket members

60

preferably includes a base portion

62

having a sidewall

70

shaped to define an internal chamber

72

and a top aperture

64

that is shaped to removably receive the plate ball member

114

of one of the pair of tow bars

110

. The sidewall

70

further defines a bar slot

66

. The bar slot

66

preferably extends from the top aperture

64

into the sidewall

70

, the bar slot

66

being shaped to receive the one of the pair of tow bars

110

when the plate ball member

114

is inserted into the internal chamber

72

. The bar slot

66

is preferably smaller than the diameter of the plate ball member

114

to prevent the escape of the plate ball member

114

through the bar slot

66

; however, if a bearing element similar to the top and bottom socket bearing elements

34

and

36

is used, it is possible for the bar slot

66

to have a larger diameter than the plate ball member

114

.

Bearing Elements

Each of the pair of socket members

60

preferably includes one of a pair of plastic bearing elements. Each of the plastic bearing elements has an outside surface and a contoured inside surface. The outside surface is shaped to fit securely within the internal chamber

72

of one of the pair of socket members

60

. The contoured inside surface is shaped to provide a bearing surface for the plate ball member

114

when it is positioned within the internal chamber

72

. It is important that the outside surface fit relatively securely against the socket member

60

because the plastic of the plastic bearing element is typically not strong enough to contain the plate ball member

114

by itself, but requires the underlying support provided by the socket member

60

. It is important that the contoured inside surface securely engage the plate ball member

114

so that the plate ball member

114

does not slip out of the socket member

60

. While it is possible to design a single plastic bearing element that will functionally support the plate ball member

114

, it is preferred that the plastic bearing element be constructed of two parts so that they can be assembled around the plate ball member

114

for the tightest fit.

As shown in

FIG. 6

, each of the plastic bearing elements preferably includes a top bearing element

90

and a bottom bearing element

92

. The top bearing element

90

has a top contoured inside surface

94

and the bottom bearing element

92

has a bottom contoured inside surface

96

, the top and bottom contoured inside surfaces

94

and

96

cooperating to provide a bearing surface around the plate ball member

114

when it is positioned within the internal chamber

72

. The top bearing element

90

has a top outside surface

98

and the bottom bearing element

92

has a bottom outside surface

100

, the top and bottom outside surfaces

98

and

100

cooperating to fit securely within the internal chamber

72

. The top and bottom bearing elements

90

and

92

preferably provide top and bottom bearing slots

102

and

103

, respectively, that together enable the tow bar

110

but not the plate ball member

114

to escape from within the top and bottom contoured inside surfaces

94

and

96

.

Cap Portion

Each of the pair of socket members

60

preferably includes a means for blocking the top aperture

64

to prevent the plate ball member

114

from escaping from the internal chamber

72

. As shown in

FIGS. 1 and 6

, the means for blocking the top aperture

64

preferably includes a pair of cap portions

80

, each of the pair of cap portions

80

being shaped to fit over and block the top aperture

64

to removably lock the plate ball member

114

within the one of the pair of socket members

60

.

Each of the pair of cap portions

80

includes a means for locking each of the pair of cap portion

80

onto one of the pair of socket members

60

. The means for locking is preferably at least one locking pin

68

that fits through the sidewall

70

and into the cap portion

80

; however, those skilled in the art can devise alternative pins, screws, locking arms, and hinges to removably attach the cap portion

80

to the sidewall

70

.

Each of the pair of cap portions

80

preferably includes an annular flange

84

that extends downwardly from the cap portion

80

to cover the top aperture

64

and fit snugly around the sidewall

70

. The annular flange

84

not only serves to position the cap portion

80

on the socket member

60

, it also serves to removably close the top of the bar slot

66

, thereby providing additional structural integrity to the socket member

60

.

The pair of socket members

60

are preferably operably positioned and laterally spaced by a tow plate

86

. The tow plate

86

is adapted to be fixedly attached to the towed vehicle

16

, preferably by fastening the tow plate

86

to the towed vehicle

16

with bolts, or by welding the tow plate

86

to the undercarriage of the towed vehicle

16

. The tow plate

86

, which must be rigid and strong, is preferably constructed of steel.

Means for Adjusting the Length of the Pair of Tow Bars

The tow bar apparatus preferably further includes a means for adjusting the length of each of the pair of tow bars

110

. Each of the pair of tow bars

110

preferably includes a first portion

124

forming the first end

112

of the tow bar

110

, and a second portion

126

forming the second end

116

of the tow bar

110

. The first portion

124

is telescopically engaged with the second portion

126

. The first and second portions

124

and

126

preferably include a means for preventing disengagement between the first portion

124

and the second portion

126

; and wherein the means for adjusting the length of each of the pair of tow bars

110

includes a locking element

132

that removably engages both the first and second portions

124

and

126

to prevent movement of the first portion

124

with respect to the second portion

126

.

As shown in

FIG. 7

, the means for preventing disengagement is preferably a first shim

128

in the first portion

124

and a second shim

130

in the second portion

126

, the first shim

128

lockingly engaging the second shim

130

to prevent the first portion

124

from sliding out of the second portion

126

. The means for adjusting the length of each of the pair of tow bars

110

preferably includes a pivot point

134

fixedly attached to the second portion

126

, the locking element

132

being pivotally attached to the pivot point

134

for pivoting the locking element

132

between a locked position, in which the locking element

132

lockingly engages a locking notch

136

of the first portion

124

, and an unlocked position in which the locking element

132

does not engage the locking notch

136

. The pivot point

134

preferably further includes a pivot locking pin

138

that engages a pin bore

139

adjacent the pivot point

134

to lock the an locking element

132

in the locked position. Obviously, these elements can be reversed, or substituted with equivalent mechanisms, and such equivalent designs should be considered within the scope of the claims described below.

In an alternative embodiment, as shown in

FIG. 8

, the means for adjusting the length of each of the pair of tow bars

110

is provided by a pair of position locking bolts

140

than lockingly engage each of the first portion

124

and the second portion

126

. Obviously, combinations of these features, as well as a variety of locking arms, locking bolts, spring loaded pins, and other mechanisms can be devised by those skilled in the art, and such modifications should be considered equivalent to the structures described herein.

As shown in

FIGS. 9 and 10

, the hitching portion

22

is preferably pivotally connected to the hitch socket member

24

with a means for pivoting the hitching portion

22

with respect to the hitch socket member

24

. The means for pivoting is preferably provided by a hitch member pivot bolt that pivotally locks the hitching portion

22

between a pair of pivot flanges

152

that extend forward of the hitch socket member. Each of the pair of pivot flanges

152

further includes a curved slot

154

shaped to slidably receive a positioning and locking bolt

156

that can be used to removably lock the hitching portion

22

at a given angle with respect to the hitch socket member

24

.

While the invention has been described with reference to at least one preferred embodiment, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with the appended claims.