AU2004237841A1 - Weight distributing hitch assembly - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: DRAW-TITE, INC.

Invention Title: WEIGHT DISTRIBUTING HITCH ASSEMBLY The following statement is a full description of this invention, including the best method of performing it known to

US:

0 a o WEIGHT DISTRIBUTING HITCH ASSEMBLY 00 BACKGROUND OF THE INVENTION The present invention relates to a vehicle hitch assembly, and more particularly o to hitch assembly that transmits and distributes a part of the load from the trailer to the a front and rear wheels of the towing vehicle.

Hitch assemblies for more evenly distributing the tongue weight of a trailer over the front and rear axles of a towing vehicle are well known in the art. A typical hitch assembly includes a hitch bar for receipt in a receiver mounted to the vehicle and a ball mount head for mounting on the hitch bar at a selected tilt angle. A pair of spring bars are.mounted at their proximal ends to the ball mount head. The distal ends of these spring bars are connected by cooperating lift units and chains to the frame of the trailer.

A typical lift unit incorporates a body that is mounted to the trailer frame, a pivoting chain hook, and a safety clip for securing the chain hook in an operative position. As is known in the art, the amount of leveling or load transfer to the front axle of the vehicle is adjusted by engaging different links of the chains with the chain hooks of the lift units.

While such an arrangement is effective for its intended purpose, the lift units must be properly mounted to the trailer frame and the proper chain links engaged in the chain hooks in order to provide proper operation and a desired distribution of weight.

While relatively simple, these procedures require some time to complete and may be difficult to accomplish. Moreover, this arrangement may interfere with side mounted tongue jacks typically found on lightweight trailers.

Accordingly, it is desirable to provide a weight distributing hitch assembly

-IA-

02 0 allowing greater ease and convenience of installation and operation. This is particularly o true with respect to the connection of the distal end of the spring bars to the trailer frame in order to provide the weight distributing action.

SUMMARY OF THE INVENTION According to one aspect of the present. invention, there is provided a weight distributing trailer hitch assembly comprising: 00 a hitch head capable of interconnecting a vehicle hitch and a trailer frame; en a single spring bar connected at its proximal end to said hitch head and extending rearwardly therefrom wherein said spring bar defines a jack accessible area o whereby said spring bar does not interfere with a trailer jack connected to said trailer frame; and a lift assembly supported by said trailer frame and capable of supporting said spring bar during engagement.

According to a further aspect of the present invention, there is provided a weight distributing trailer hitch assembly comprising: a shank for connection with a vehicle hitch; a hitch head connected to said shank, said hitch head including means for connecting to a trailer frame; a single spring bar connected at its proximal end to said hitch head and extending rearwardly therefrom wherein said spring bar defines a jack accessible area so that said spring bar does not interfere with a trailer jack connected to said trailer frame; and a lift assembly connected to said trailer frame and capable of supporting said spring bar during engagement.

According to a further aspect of the present invention, there is provided a single spring bar for use in a weight-distributing trailer hitch assembly interconnecting a trailer frame and a trailer hitch, said single spring bar comprising: an end segment for connection to said weight-distributing trailer hitch assembly; a cantilever segment extending rearwardly from said end segment wherein a portion of said cantilever segment defines ajack accessible area whereby said cantilever segment does not interfere with a trailer jack connected to said trailer frame.

BRIEF DESCRIPTION OF THE DRAWINGS The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred o embodiment. The drawings that accompany the detailed description can be briefly described as follows: Figure I A is a side view of a vehicle weight distributing hitch assembly .4 according to an embodiment of the present invention; 00 Figure 1 B is an expanded top view of the vehicle weight distributing hitch assembly illustrated in Figure IlA; .4 10 Figure 10C is a side view of a lift assembly engaged with the spring bar; o Figure 2A is a side view of another embodiment of a vehicle weight distributing hitch assembly according to an embodiment of the present invention; Figure 28 is an expanded top view of the vehicle weight distributing hitch assembly illustrated in Figure 2A; Figure 3A is an expanded view of a lift assembly according to an embodiment of the present invention; Figure 3B is a top view of the lift assembly illustrated in Figure 3A; Figure 4 is an expanded view of a hanger assembly according to an embodiment of the present invention; Figure 5 is an expanded view of the lift assembly illustrated in Figure 3 detailing operation of the hanger assembly and lever assembly; Figure 6A is an expanded view of another lift assembly according to an embodiment of the present invention detailing operation of the hanger assembly and lever assembly; Figure 6B is a top view of the lift assembly illustrated in Figure 6A; Figure 7 is an expanded view of another hanger assembly according to an embodiment of the present invention; Figure 8 is an expanded view of another hanger assembly according to an embodiment of the present invention; Figure 9A is an expanded view of another lift assembly utilizing the hanger assembly illustrated in Figure 8; Figure 9B is an expanded view of the lift assembly base illustrated in Figure 9A; Figure 10 is a side view of the lift assembly illustrated in Figure 9A attached to a trailer; Figure I1I is an expanded view of another embodiment of a lever assembly for use with the lift assembly illustrated in Figure 9A; -4 0 Figure 12 is an expanded view of yet another hanger assembly according to an U embodiment of the present invention; Figure 13 is an expanded view of another lift assembly utilizing the hanger o assembly illustrated in Figure 12; Figure 14 is an expanded top view of the lever assembly illustrated in Figure 13; __Figure 15 is an expanded view of yet another ,eefassembly according to an embodiment of the present invention; 00 Fgr 6 sa xaddve fapvtfrtelvrasml fFgr Figure 16A is an expanded view of ane pivot for the lever assembly of gr Figure o Figure 17 is an expanded view of another lift assembly utilizing the lever assembly illustrated in Figure DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1IA illustrates a weight distributing hitch assembly 10 for attachment to a vehicle 12. The hitch assembly 10 generally includes a shank 14, head 16, spring bar 34 and lift assembly 20. The shank 14 is sized to have exterior dimensions for mating engagement within a female hitch end 22 mounted to the vehicle 12. Preferably, a hitch pin 15 or the like retains the shank 14 within the female hitch end 22.

The head 16 is preferably adjustable relative to the shank 14. Ap ertures 24 through the shank 14 correspond with apertures 25 through the head 16 to receive fasteners 26 such as bolts 26. The height of the head 16 is adjusted relative to the shank 14 to align the trailer frame 28 of the trailer 30 with the female hitch end 22. Once the.

head 16 is adjusted to the desired height along the shank 14, the fasteners 26 are inserted through the apertures 24 to retain the head 16 to the shank 14.

The head 16 further includes a vertical pivot 32 to receive a spring bar 34. The spring bar 34 is preferably an elongated cantilever spring member that is detachably and pivotally mounted adjacent a hitch ball socket assembly 36 mounted to the trailer frame 28. The trailer frame 28 is connected to a towing ball 38 or the like which is mounted to the head 16. The specific attachment of the hitch ball socket assembly 36 and towing ball 38 forms no part of the present invention and it should be understood that many arrangements will benefit from the present invention.

As will be futrther described below, the lift assembly 20 includes a hanger assembly 42 which engages a cantilevered segment 44 of the spring bar 34. The spring bar 34 is preferably L-shaped such that the cantilevered segment 44 is substantially perpendicular to a mount segment 45 which engages the vertical pivot 32. The cantilevered segment 44 and the mount segment 45 are located within a common plane 0 (Figure iB), however, as described in another embodiment (Figures 2A, and 2B) a portion of the cantilevered. segment 44 can extend from the common plane to benefit other trailer frame configurations.

o The hanger assembly 42 is movable by the lift assembly 20, to engage the cantilevered segment 44 of the spring bar 34 and drive the spring bar 34 from its free state (shown in phantom at F) to a loaded state L. As the spring bar 34 is preferably manufactured of a resilient material such as steel, the spring bar 34 will resist the loaded 00 state L and will attempt to return to its free state F. In its loaded state L, the spring bar Cfl 34 transfers a part of the load from the trailer 30 to the towing vehicle 12 and serves to .4 10 distribute the hitch load to the wheels 46 of the towing vehicle 12 as well as to the o trailer wheels 48.

Referring to Figure lB, the lift assembly 20 is preferably removably mountable to the trailer frame 28 by a clamp 40 or the like. The lift assembly 20 is preferably mounted above the frame members 50 of the trailer frame 28 and the spring bar 34 extends below the frame members 50 relative to the ground 51 (Figure IA). By locating the lift assembly 20 above the trailer frame 28 and the spring bar 34 below, only a small position retaining clamp such as clamp 40 is required to retain the lift assembly 20. The lift assembly 20 can thereby be rapidly installed and disconnected to be conveniently stored when the hitch is not in use.

As illustrated in Figure lB, the spring bar 34 is substantially straight and runs substantially parallel to a longitudinal axis 55 defined by the trailer frame 28. Although an A-frame type trailer frame is illustrated in the disclosed embodiment, it should be realized that many trailers will benefit from the present invention. Preferably, the hanger assembly 42 extends through an opening 53 in the lift assembly 20 base 52 to engage the cantilevered segment 44 of the spring bar 34 (Figure IC).

Referring to Figure 2A another trailer frame 28 is illustrated. The trailer frame 28 includes a cent er-mounted trailer tongue jack 6. The components of the weight distributing hitch assembly 10 are otherwise substantially similar to the embodiment of Figure IJA, IDB and identical numerals are used.

Refer-ring to Figure 2B, the center-mounted trailer tongue jack 6 is located along a longitudinal axis 55 defined by the trailer frame 28. The spring bar 34 is preferably bent to clear the center-mounted trailer tongue jack 6. Accordingly, with only the substitution of spring bar 34 another trailer framne 28 configuration will benefit from the present 'invention.

Referring to Figure 3A, one embodiment of the lift assembly 20 is illustrated.

The lift assembly 20 is removably mounted to a frame member 50 of the trailer frame 28 by the clamp 40. A lever assembly 54 mounts the hanger assembly 42 to the lift 0 assembly 20 base 52. The lever assembly 54 includes a handle 57 which drives a camn o 56 about a pivot 58. The pivot 58 includes an axle pin 60 such as a bolt which passes through the cam $6 and the base 52 (Figure 3B).

o Referring to Figure 4, the hanger assembly 42 includes a wire form 62 whic~h retains a threaded fastener 64 such as a nut. The threaded fastener 64 is preferably fixed to the wire forn 62 by welding or the like. The threaded fastener 64 receives a threaded rod 66 which is attached to a hook 68. The hook 68 is adjustable for length by 00 threading the threaded rod 66 into the threaded fastener 64. Accordingly, rather small en incremental adjustments can be made in the position of the hook relative to the lift N 10 assembly 20 (Figure 1) for the leveling requirements of different tow vehicles and

,'I

o trailer combinations.

N Referring to Figure 5, operation of the lift assembly 20 is illustrated. Lever assembly 54 is fixed to cam 56. By moving the lever assembly 54 in the direction of a rrow R, the cam 56 moves about pivot 58. The wire form 62 is engaged with the camn 56, the hanger assembly 42 is driven from a disengaged position D to an engaged position E. Accordingly, the spring bar 3 4 (Figure IlA) is moved from its free state F to its loaded state L. Moreover, the lever assembly 54 and cain 56 supplies mechanical advantage to assist a user during tensioning of the spring bar 34.

To install the weight distributing hitch assembly 10 the user lowers the trailer frame 28 onto the head 16 (Figure IA). The user installs the spring bar 34 into the vertical pivot 32 on the head 16 and lowers the adjustable hanger assembly 42 on the lift mechanism 20 by rotating the lever assembly 54 per Figure 5. The consumer swings the spring bar 34 under the trailer frame 28 and places it in the adjustable hanger assembly 42. The user raises the adjustable hanger assembly 42 by rotating the lever assembly 54. The consumer is then ready to tow. The adjustable hook 68 may be raised or lowered via threaded rod 66 and hex nut 64 (Figure 4) for the leveling requirements of different tow vehicles and trailer combinations.

Referring to Figure 6A, another embodiment of the lift assembly 20 is illustrated. The lift assembly 20 includes a lever assembly 70 which mounts the hanger assembly 42 with a crank 72. The crank 72 is driven by a handle 74 to rotate the crank about a pivot 76. The pivot 76 includes an axle pin 60 such as a bolt which passes through the crank 72 and base 52 (Figure 6B). The crank 72 preferably includes a support pin 75 which supports the wireform 62 of the hanger assembly 42. The crank 72 rotates about the pivot 76 to again supply a mechanical advantage to drive the hanger assembly 42 from a disengaged position D to an engaged position E.

-7- 0Referring to Figure 7 another embodiment of a hanger assembly 78 is o illustrated. A fonined or stamped hook 80 is welded to a hex nut 82 and an eye bolt 84 is threaded into the hex nut 82.

o Referring to Figure 8 another embodiment of a hanger assembly 86 is illustrated. A U-shaped bracket 88 engages the cantilevered segment 44. A fastener passes through an aperture 92 in the U-shaped bracket 88 and is retained by a hex nut 94. The fastener 90 engages a length of chain 96. Although the fastener 90 is engaged 00 with an end link 98 of the chain 96 it should be realized that the fastener 90 can be engaged with any link 98 to thereby adjust the load placed on the cantilevered segment 44.

o) Referring to Figure 9A, another embodiment of a lift assembly 100 is illustrated.

The lift assembly 100 mounts a lever assembly 102 which mounts the hanger assembly 86. The lever assembly 102 includes a pivot 104 and retention hook 106. Preferably, a U-shaped bracket 10 8 is attached to a handle 1 10. The retention hook 106 is located between the legs of the U-shaped bracket 108 while the pivot 104 extends from the exterior of the U-shaped bracket 108. The retention hook 106 is offset from the pivot 104 such that the retention hook 106 is cammed about the pivot 104 to again supply a mechanical advantage to drive the hammer assembly 86 from a disengaged position D to an engaged position E.

Preferably, the lift assembly 100 includes a base 112 which provides a plurality of slots 114 to receive the pivot 104 (Figure 9B). The slots 114 are located along a ramped surface 118 of the base 112 to provide an adjustab le lift range H between the disengaged position D) and engaged position E. The pivot 104 includes an axle pin 116 that fits within the slots 114. By locating the axle pin 116 in one of the slots 114 of the left assembly 100, adjustment of the lift range between the disengaged position D and engaged position E is provided.

In addition, a plurality of clamp mounting apertures 120 are preferably located along the length of the base 112. -The clamp mounting apertures 120 receive a clamp 122 such as a U-bolt which is engageable with a frame member 50. In addition to allowing the lift assembly 100 to be removably mounted to a fr-ame member 50, clamp mounting apertures 120 simplify the attachment of the lift assembly 100 to multiple types of trailer frames. In use, the lift assembly 100 is located in the desired position along the frame members 50 and the clamp 122 is engaged with the appropriate clamp mounting apertures 120. Moreover, by adjusting the mounting location of the lift assembly 100 relative to the frame members 50 and along the trailer axis 55 (Figure additional adjustment of the lift range between the disengaged position D and 0 engaged position E is provided. Flexibility is also provided in fitting around trailer o frame obstructions.

By moving the lever assembly 102 in the direction of arrow R, the retentioni o hook 106 moves about the pivot 104. The chain 96 is engaged with the retention hook 106 and the hanger assembly 86 is driven from a disengaged position D to an engaged position E. Accordingly, the spring bar 34 (Figure 10) is moved from its free state F to its loaded state L. As described above, by adjusting the lift assembly 100 along the 00 framne members 50, by locating the pivot in one of the slots 114, by engaging the Cfl retention hook 106 and fastener 92 in the links 98 in the chain 96, multiple adjustments to the lift range H for multiple types of trailers 38 are provided and flexibility in fitting o around obstructions on various trailer frames.

Referring to Figure 11, another embodiment of a lever assembly 124 is illustrated. The lever assembly 124 is a one-piece casting including a retention hook 126 attached to a handle 128. The retention hook 126 is located between the legs of a U-shaped pivot 130 which includes integrally cast pivot pins 132.

Referring to Figure 12 another embodiment of a hanger assembly 134 is illustrated. The hanger assembly 134 includes a coupler 136 having a threaded fastener 138 attached at each end. One threaded fastener 138 receives an eye-bolt 140 while the threaded J-hook can thereby be adjusted by adjusting the threaded hex nut 172 along the threaded J-hook 170.

Referring to Figure 16B, another embodiment of the hanger axle 166 is illustrated. The hanger axle 166 is a cylinder having an aperture 168 located therethrough to receive the threaded J-hook 170.

The threaded I-hook 170 engages the hanger assembly 86 described in Figure 8.

Preferably, hanger axle 166 is rotatably retained in the lever assembly 164 between a pair of plates 174 such that the banger axle is free to rotate on the circular pivots 167.

Each plate 174 further includes a pivot 176.

Referring to Figure 17, another embodiment of a lift assembly 178 including the hanger assembly 86 of Figure 8 and the lever assembly 164 of Figure 15. The lift assembly 178 includes a base 180 which mounts the lever assembly 164 at pivot 176.

The hanger axle 166 pivots between the plates 174 such that the hanger assembly 86 pivots thereon during rotation of the lever assembly 164. The pivot 176 is offset from the hanger axle 166 such that the hanger axle 166 and attached hanger assembly 86 is carnmed about the pivot 176 to supply a mechanical advantage to drive the hanger assembly 86 from a disengaged position D to an engaged position E. Moreover, as the hanger axle 166 pivots during operation of the lever assembly 164, the hanger assembly 86 chain 96 of Figure 8 is prevented from becoming tangled.

c-i Although, particular sub-assemblies such as the bent and straight spring bars, lever assemblies, lift assemblies, hanger assemblies, and such may be illustrated in particular embodiments as associated with certain other sub-assemblies, it will be O realized that other combinations will benefit from the teachings of the present invention.

The foregoing description is exemplary rather than defined by the limitations within. Many modifications and variations of the present invention are possible in light 00 of the above teachings. The preferred embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be O understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word "comprises" has a corresponding meaning.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in -the art, in Australia or any other country.

The entire disclosure in the complete specification of our Australian patent Application No.45982/CO is by this cross-reference incorporated into the present specification.

Claims (10)

1. 2. The weight distributing trailer hitch assembly of claim 1 wherein said jack accessible area is defined by at least a portion of said spring bar extending laterally from a preceding portion of said spring bar.
2. 3. The weight distributing trailer hitch assembly of claim 2 wherein the laterally extending portion of said spring bar extends at an angle from the preceding portion of said spring bar.
3. 4. The weight distributing trailer hitch assembly of claim 3 wherein the angle between the laterally extending portion of said spring bar and the preceding portion of said spring bar is obtuse. A weight distributing trailer hitch assembly comprising: a shank for connection with a vehicle hitch: a hitch head connected to said shank, said hitch head including means for connecting to a trailer frame; a single spring bar connected at its proximal end to said *hitch head and extending rearwardly therefrom wherein said spring bar defines a jack accessible area so that said spring bar does not interfere with a trailer jack connected to said trailer frame; and a lift assembly connected to said trailer frame and capable of supporting said spring bar during engagement.
4. 6. The hitch assembly of claim 5 wherein said hitch head is connected to said shank in a vertically adjustable manner. 11
5. 7. The hitch assembly of claim 6 wherein said spring bar is removably o connected to said hitch head. O 8. The hitch assembly of claim 7 wherein said trailer frame comprises an A-frame having a first and a second trailer frame member.
6. 9. The hitch assembly of claim 8 wherein a base member spans said first 00 and second trailer frame members and said lift assembly is mounted thereon. 10 10. The hitch assembly of claim 9 wherein said base member is removably O o connected to said first frame member.
7. 11. A single spring bar for use in a weight-distributing trailer hitch assembly interconnecting a trailer frame and a trailer hitch, said single spring bar comprising: an end segment for connection to said weight-distributing trailer hitch assembly; a cantilever segment extending rearwardly from said end segment wherein a portion of said cantilever segment defines a jack accessible area whereby said cantilever segment does not interfere with a trailer jack connected to said trailer frame.
8. 12. The spring bar of claim 11 wherein said jack accessible area is defined by at least a portion of said cantilever segment extending laterally from a preceding portion of said cantilever segment.
9. 13. The spring bar of claim 12 wherein the laterally extending portion of said cantilever segment extends at an angle from the preceding portion of said cantilever segment.
10. 14. The spring bar of claim 13 wherein the angle between the laterally extending portion of said cantilever segment and the preceding portion of said cantilever segment is obtuse. A hitch assembly as claimed in any one of claims 1 to 10, and substantially as herein described with reference to the accompanying drawings. -12 o 16. A spring bar as claimed in any one of claims 11 to 14, and substantially as herein described with reference to the accompanying drawings. O Dated this 10th day of December 2004 DRAW-TITE. INC. By their Patent Attorneys 0 0 GRIFFITH HACK Cfl Fellows Institute of Patent and 10 Trade Mark Attorneys of Australia 0 0 ci