AU2013221947B2 - Trailer hitch shock dampening system - Google Patents

Description

1 2013221947 27 Aug 2013

TITLE

TRAILER HITCH SHOCK DAMPENING SYSTEM FIELD OF THE INVENTION 5 This invention relates generally to a trailer hitch shock dampening system, and in particular to a trailer hitch shock dampening system for reducing vibrations and forces transmitted to a vehicle when a trailer is being towed.

10 BACKGROUND OF THE INVENTION A common problem when towing a trailer or a caravan behind a vehicle is that vibrations and forces, caused generally by accelerations, decelerations, or uneven road surfaces, are transmitted through the trailer hitch to the vehicle, such that the vibrations and forces become 15 uncomfortable for the driver and passengers of the vehicle. This problem is often exacerbated when towing heavy loads or under severe braking, and may cause the vehicle to lurch, making driving the vehicle more difficult and potentially dangerous.

Various prior art systems have been developed that are integrated 20 into a trailer or trailer hitch in order to reduce the effects described above, and thus provide a smoother ride in the vehicle.

Some systems utilise a gas filled shock absorber coupled between the vehicle and the trailer in order to absorb the vibrations. However, the level of absorption is generally fixed by the shock absorber, and thus cannot be 25 adjusted to suit different road conditions and different loads.

In order to overcome this problem, other systems have been developed that utilise an air cushion to absorb the shocks. A level of absorption may be varied by pumping air into the air cushion, or releasing air from the air cushion. 30 In one such air cushion system, a sleeve is mounted to a frame of the trailer, nearest to the towing vehicle, and an arm is pivotally connected to the sleeve. A proximal end of the arm is coupled to the towing vehicle, using a 2 2013221947 27 Aug 2013 hitch coupling. A distal end of the arm sandwiches the air cushion between it and a cross member of the trailer. Vibrations and forces applied to the trailer hitch cause the arm to pivot, such that the vibrations and forces are absorbed by the air cushion. However, a problem with this solution is that it is 5 integrated into the trailer, and requires modification of a standard trailer frame.

Bolt-on dampening systems, which do not require modification of a standard trailer frame, have also been developed. However, such systems generally include obtrusive elements that either interfere with hitching the 10 trailer or reduce the amount of ground clearance of the vehicle.

There is therefore a need for an improved trailer hitch shock dampening system.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the 15 prior art forms part of the common general knowledge in Australia or elsewhere.

OBJECT OF THE INVENTION

It is an object, of some embodiments of the present invention, to 20 provide consumers with improvements and advantages over the above described prior art, and/or overcome and alleviate one or more of the above described disadvantages of the prior art, and/or provide a useful commercial choice.

25 SUMMARY OF THE INVENTION

In one form, although not necessarily the only or broadest form, the invention resides in a trailer hitch shock dampening system including: a base defining a longitudinal axis and a pivot axis substantially perpendicular to the longitudinal axis; 30 an arm pivotally connected to the base about the pivot axis, the arm including a first end and a second end; a coupling connected to the first end of the arm; and 2013221947 27 Aug 2013 3 a dampener mounted between the base and the second end of the arm; wherein the coupling, pivot axis and dampener are positioned substantially along the longitudinal axis. 5 Preferably the longitudinal axis is substantially orthogonal to an operating axis of the dampener.

Preferably, the dampener is an air cushion.

Suitably, the base includes a first end and a second end. Preferably, the dampener is mounted between the second end of the arm and the 10 second end of the base.

Optionally, the coupling is bolted to the arm. Alternatively, the coupling is integral with the arm.

Preferably, the arm includes a protrusion to accommodate the dampener. Preferably the protrusion is located at a second end of the arm. 15 Optionally, the base includes a protrusion.

Optionally, the base and the arm have a U shaped cross section.

Preferably, the cross section of the base is smaller than the cross section of the arm. Preferably, opposing side walls of the base fit inside opposing side walls of the arm. 20 Preferably, bearings are positioned between each side wall of the base and each side wall of the arm.

Preferably, the base includes pivot holes formed in the side walls of the base.

Preferably, captive nuts are positioned on an inside of the side walls. 25 Preferably, the captive nuts align with the pivot holes formed in the side walls of the base.

Preferably, the arm is pivotally connected to the base using bolts.

Preferably, the arm includes a tongue for mounting the dampener.

Preferably, the base includes a tongue for mounting the dampener. 30 Preferably, the dampener is mounted between the tongue of the arm and the tongue of the base. 4 2013221947 27 Aug 2013 BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will be described with reference to the accompanying drawings in which: FIG 1 illustrates a side view of a trailer hitch shock dampening system 5 mounted between a trailer and a vehicle; FIG 2 illustrates a front perspective view of the system of FIG 1 in isolation; FIG 3 illustrates a partially assembled bottom perspective view of the system of FIG 2; 10 FIG 4 illustrates a dismantled side view of the system of FIG 2; FIG 5 illustrates an assembled side view of the system of FIG 2; and FIG 6 illustrates a close-up front perspective view of the system of FIG 2 mounted to the trailer.

15 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Elements of the invention are illustrated in concise outline form in the drawings, showing only those specific details that are necessary to understanding the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of 20 ordinary skill in the art in light of the present description.

In this patent specification, adjectives such as first and second, left and right, front and back, top and bottom, etc., are used solely to define one element from another element without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such 25 as “comprises” or “includes” are not used to define an exclusive set of elements or method steps. Rather, such words merely define a minimum set of elements or method steps included in a particular embodiment of the present invention. It will be appreciated that the invention may be implemented in a variety of ways, and that this description is given by way of 30 example only. FIG 1 illustrates a side view of a trailer hitch shock dampening system 100 mounted to a trailer 200 which is towed by a vehicle 300. The system 5 2013221947 27 Aug 2013 100 absorbs vibrations and forces transmitted through the road or by relative accelerations between the trailer 200 and vehicle 300 caused by braking or cornering, and reduces the effects felt by a driver of the vehicle 300. Although FIG 1 shows that the system 100 is mounted to a trailer 200, it 5 should be appreciated that the present invention may be applied to any other suitable towed vehicle such as a caravan. FIG 2 illustrates a front perspective view of the system 100 of FIG 1 in isolation, FIG 3 illustrates a partially assembled bottom perspective view of the system 100 of FIG 2, FIG 4 illustrates a dismantled side view of the 10 system of FIG 2 and FIG 5 illustrates an assembled side view of the system of FIG 2. As shown in FIGs 2-5, the system 100 includes a base 110, an arm 120, a coupling 130 and a dampener 140.

Referring to FIGs 2 - 5, the base 110 includes a first end 110a and a second end110b. Similarly, the arm 120 includes a first end 120a and a 15 second end 120b. The base 110 and the arm 120 are made from a generally U shaped metal channel. A cross-section of the base 110 is narrower than a cross section of the arm 120 such that opposing side walls 110c of the base 110 fit inside opposing side walls 120c of the arm 120.

The base 110 includes mounting holes 111 positioned in a bottom 20 surface 110d to allow the system 100 to be mounted to a frame of the trailer 200 using, for example, a suitable nut and bolt arrangement.

The arm 120 also includes mounting holes (not visible) positioned in a top surface 120d which line up with corresponding holes in a plate 131 of the coupling 130. The coupling 130 is mounted to the arm 120 using suitable 25 nuts 132 and bolts 133 placed through the mounting holes and the plate 131, such that a connection to the vehicle 300 is located adjacent the first end 120a of the arm 120. It should also be appreciated that that coupling 130 may be mounted to the arm 120 using any other suitable method such as welding. In addition, the arm 120 and the coupling 130 may be integrally 30 formed.

The base 110 includes pivot holes 112 formed in the side walls 110c of the base 110. Captive nuts 113 are positioned on an inside of the side 6 2013221947 27 Aug 2013 walls 110c. The captive nuts 113 align with the pivot holes 112 formed in the side walls 110a of the base 110.

The arm 120 also includes pivot holes 121 formed in the side walls 120c, which correspond with the pivot holes 112 formed in the side walls 5 110c of the base 110 when the base 110 is mounted inside the arm 120.

The arm 120 is pivotally connected to the base 110 using bolts 102 which pass through each of the pivot holes 121, 112 to define a pivot axis and engage the captive nuts 113 in the base 110. In one embodiment, bearings 101 are positioned between each side wall 110c of the base 110 10 and each side wall 120c of the arm 120. However it should be appreciated that any suitable arrangement may be used to pivotally mount the arm 120 to the base 110, depending on a type of base 110 or arm 120 used. In addition, although the base 110 and the arm 120 are U-shaped, it should be appreciated that the base 110 and the arm 120 may form any suitable shape 15 in order to pivotally connect the base 110 to the arm 120.

The coupling 130 is a standard coupling in order to connect the trailer 200 to a towing hitch of the vehicle 300. In the embodiment shown in the figures, the coupling 130 is a gooseneck coupling thus it is able to rotate in two orthogonal axes. However, it should be appreciated that any suitable 20 coupling 130 may be used, such as a ball and socket coupling, which has more limited rotational abilities.

The dampener 140 is preferably an air cushion, and in one embodiment the dampener 140 is cylindrical in shape. As shown in FIG 2, the dampener 140 is mounted such that a first plane X, of a longitudinal axis 25 of the base 110 is substantially orthogonal to an operating axis Y of the dampener 140.

In one embodiment, the dampener 140 is mounted between the second end 110b of the base 110 and the second end 120b of the arm 120. The dampener 140 is held in position using a threaded bolt 141 which 30 passes through a tongue 122 formed in the arm 120 and a tongue 114 formed in the base 110. Thus the dampener is mounted between the tongue formed of the arm and the tongue formed of the base. The bolt 141 is then 7 2013221947 27 Aug 2013 secured with nuts 142 placed on either end of the bolt 141. An advantage of this arrangement is that the dampener 140 does not protrude significantly above the base 110.

In one embodiment, the arm 120 includes a protrusion 123 in order to 5 accommodate a height of the dampener 140. However it should be appreciated that the size of the protrusion 123 will depend on the size of the dampener 140. In addition, or alternatively, the base 100 may include a protrusion for receiving an end of the dampener 140.

The dampener 140 also includes an inflation/deflation device 143 in 10 order to vary the firmness of the dampener 140 depending on a load being carried and/or the road conditions.

In use, the system 100 is secured to an apex 211 of a frame 210 of a trailer 200, as shown in FIG 6, using a suitable nut and bolt arrangement. Alternatively, the system 100 may be mounted to the trailer 200 using any 15 suitable permanent, semi-permanent or quick release mechanism. Once mounted to the trailer 200, a user may vary the firmness of the dampener 140 in order to suit an expected road surface or a type of trailer 200 being towed. The trailer 200 is then connected to a towing hitch of the vehicle 300.

In summary, some advantages of some embodiments of a system of 20 the present invention include: 1) The system absorbs vibrations and forces transmitted through the trailer to the vehicle, and thus provides a smoother ride to persons travelling in the vehicle; 2) Due to the dampening of vibrations and shock forces, the system 25 makes towing generally safer; 3) The system does not protrude excessively in a vertical direction, and thus does not interfere with hitching and unhitching a trailer, and does not limit ground clearance; and 4) The system can be easily removed and mounted to another trailer. 30 The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a 2013221947 27 Aug 2013 8 single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or 5 relatively easily developed by those of ordinary skill in the art. Accordingly, this patent specification is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims (20)

1. Claims:

   1. A trailer hitch shock dampening system for mounting to a trailer, including: a base, adapted to be mounted independently to the trailer, defining a longitudinal axis and a pivot axis substantially perpendicular to the longitudinal axis; an arm pivotally connected to the base about the pivot axis, the arm including a first end and a second end; a coupling connected to the first end of the arm; and a dampener mounted between the base and the second end of the arm; wherein the coupling, pivot axis and dampener are positioned substantially along the longitudinal axis.
2. 2. The dampening system of claim 1, wherein the longitudinal axis is substantially orthogonal to an operating axis of the dampener.
3. 3. The dampening system of claim 1, wherein the dampener is an air cushion.
4. 4. The dampening system of claim 1, wherein a portion of the dampener extends along the longitudinal axis beyond the second end of the base.
5. 5. The dampening system of claim 1, wherein the coupling is bolted to the arm.
6. 6. The dampening system of claim 1, wherein the coupling is integral with the arm.
7. 7. The dampening system of claim 1, wherein the arm includes a protrusion to accommodate the dampener.
8. 8. The dampening system of claim 7, wherein the protrusion is located at a second end of the arm.
9. 9. The dampening system of claim 1, wherein the base includes a protrusion.
10. 10. The dampening system of claim 1, wherein the base and the arm have a U shaped cross section.
11. 11. The dampening system of claim 10, wherein the cross section of the base is smaller than the cross section of the arm.
12. 12. The dampening system of claim 1, wherein opposing side walls of the base fit inside opposing side walls of the arm.
13. 13. The dampening system of claim 12, wherein bearings are positioned between each side wall of the base and each side wall of the arm.
14. 14. The dampening system of claim 12, wherein the base includes pivot holes formed in the side walls of the base.
15. 15. The dampening system of claim 12, wherein captive nuts are positioned on an inside of the side walls of the arm.
16. 16. The dampening system of claim 15, wherein the captive nuts align with the pivot holes formed in the side walls of the base.
17. 17. The dampening system of claim 1, wherein the arm is pivotally connected to the base using bolts.
18. 18. The dampening system of claim 1, wherein the arm includes a tongue for mounting the dampener.
19. 19. The dampening system of claim 1 wherein the base includes a tongue for mounting the dampener.
20. 20. The dampening system of claim 19 wherein the dampener is mounted between a tongue formed of the arm and the tongue formed of the base.