GB2206856A

GB2206856A - Towing bracket adapter

Info

Publication number: GB2206856A
Application number: GB08806619A
Authority: GB
Inventors: Stuart Fraser
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-20
Filing date: 1988-03-21
Publication date: 1989-01-18
Also published as: GB8706647D0; GB8806619D0

Abstract

The invention relates to an adapter for fitting between a towing vehicle and the ball part 1, 2 of a ball-and-socket joint of that vehicle. The adapter comprises generally a box section 9 for fitting to the towing vehicle, a U-shaped channel 10 for fitting to a ball joint and a damping mechanism eg springs 17 which acts upon both the box and the channel to damp any motion therebetween. Markings can be provided on the relatively moveable parts of the adapter which, when aligned, indicate that a trailer hitched to the coupling is properly balanced. The spring loading of the adapter helps to reduce pitch being transferred from the trailer to the towing vehicle - often a cause of travel sickness. <IMAGE>

Description

IMPROVED TOWING BRACKET This invention relates to an improved towing bracket.

Conventional towing brackets are fixed to a solid part of the towing vehicle by means of a pair of bolts. Although this method of fixing has the advantage of being very simple it has a number of inherent disadvantages.

Firstly, when the towed vehicle (which may be a trailer, horsebox, caravan or any other single axled vehicle) is connected to the towing vehicle the operator does not have any accurate indication of whether the towed vehicle is- balanced about its axle. If, for example, a caravan has much more weight behind its axle than in front then, when connected to the towing vehicle, it would tend to lift the rear wheels of the towing vehicle. This could easily lead to a dangerous situation and especially so for rear wheel drive only vehicles.

Secondly, the towing vehicle and the towed vehicle do not act as a rigid structure but can turn with respect to each other, to a limited degree, about the ball and socket joint of the towing bracket. When one vehicle is i motion on an uneven surface the occupants can experience a slightly bumpy ride, but when the two vehicles are connected together the bumping of the towed vehicle often aggravates the bumping of the towing vehicle so that the occupants thereof experience travel sickness. Even if both vehicles are double-axled occupants of the towing vehicle can still experience travel sickness due to the different effects of the suspension systems of the vehicles.

It is an object of the present invention to provide an indication of a non-balanced towed vehicle, to help prevent and/or reduce travel sickness for at least some of the occupants of the towed and towing vehicles, but, to retain a simple towing bracket construction.

According to the present invention a towing bracket adapter comprises a vehicle connecting member, capable of being fixed to one vehicle, and a bracket connector member, capable of being fixed to a towing bracket, the adapter bracket and connector being connected together by means of a resilient mechanical damping mechanism.

The vehicle connecting member preferably comprises a box construction. Such a box construction may be manufactured from a corrosion resistant material, such as stainless steel or a weatherproof enamel coated mild steel. The bracket connecting member preferably comprises a generally U-shaped channel located within the box construction.

The mechanical damping mechanism preferably comprises an opposing spring arrangement acting between the vehicle connecting member and the bracket connecting member so that both components have a tendency to move towards a balanced or no-load position.

The towing bracket adapter preferably incorporates a locking means whereby the vehicle connecting member can be locked in a fixed position relative to the bracket connector member. The locking means preferably operates upon the bracket connector so that it is maintained in a "no unbalanced load" position.

The locking means is preferably operable by means of a simple two-position switch or lever located near to (or upon) the top surface of the towing bracket adapter.

A towing bracket in accordance with the inventions will now be described, by way of example only, with reference to the accompanying drawing in which: Figure 1 is a front view of a towing bracket adapter; Figure 2 is a side view of the adapter of Figure 1; Figure 3 is a rear view of the towing bracket adapter of Figure 1; Figure 4 is a cross-sectional side view of the towing bracket adapter of Figure 1; and, Figure 5 is a perspective view of a component of the adapter of Figure 4.

A conventional towing bracket 1 comprises a partspherical ball 2 and a vertically arranged rectangular fixing plate 3 joined by an upright L-shaped connecting member 4. The towing bracket 1 is conventionally manufactured as an ordinary steel casting. In conventional use the towing bracket is fitted directly to a solid part of the rear of a towing vehicle by means of a pair of bolts 5, each passing through a respective hole 6 formed through the fixing plate 3 and a co-operating hole formed in the said solid part of the towing vehicle, and a pair of nuts 7.

In the present invention (as illustrated in Figure 2), a stainless steel or mild steel towing bracket adapter 8 is fitted between the conventional towing bracket 1 and the towing vehicle (not shown). Such a towing bracket adapter 8 generally comprises a vehicle connector member 9, for fixing to the vehicle, a bracket connector member 10, for fixing to the conventional towing bracket, and a mechanical damping means fitted between the two connector members 9 and 10.

The vehicle connector member 9 comprises a stainless steel or mild steel box 11, having an external height, width and depth of approximately 150 mm, 210 mm and 50 mm respectively, with a horizontal letter-box opening 19, the height of which is approximately 90 mm, located at mid-height in its front face.

Half way up each side wall of the box 11 is engraved a horizontal marker line 12.

In certain cases the adapter can be manufactured from a weatherproof enamel-coated mild steel.

The letter-box opening 19 is closed on the front side by means of a rectangular stainless steel or mild steel plate 18 which abuts the front face of the housing 9 and which has a pair of vertically arranged short side walls 20 embracing the side walls of the housing 9. Hrlf way up each side of the side walls 20 is engraved or marked a horizontal marker line 21. Thus when the towing bracket is in either a no-load condition or a balanced load condition (as illustrated by Figure 1) the two pairs of marker lines will align exactly.It will of course be appreciated that the invention is not limited to a mere indication of whether the towed vehicle is "balanced" or "unbalanced", but it is also envisaged that an acceptable error indication could also be provided for by means of at least a pair of marker lines 12 and a marker line 21, or even a solid marker area 21 and a marker line 12.

The box 11 is fixed to the towing vehicle by means of a pair of bolts 22, the shaft of each of which passes through a clearance hole 23 formed through the rear portion of the box 11, and a further clearance hole formed in a solid part at the rear of the towing vehicle.

The bracket connector member 10, as seen in Figures 3 and 4 comprises a U-shaped steel channel 13, which may be rust resistant, capable of moving relatively to the box 11, in a vertical direction only with the mouth of the channel opening in a rearward direction. The channel 13 is fitted to the conventional towing bracket 1 by means of a pair of bolts 5, the shaft of each of which passes through a clearance hole 14 in the vertical wall of the channel 13.

A pair of vertically oriented spring-retaining rods 15 are fitted through a pair of axially aligned holes 16 formedjthrough the two horizontal flanges of the channel 13. As seen in Figure 4 the retaining rod 15 passes through the channel section and is in contact with the top and bottom face of the box 11 so that a pair of helical compression springs 17 can be fitted around the rod one above the channel section and one below the channel section. These springs are arranged to be in compression when fitted to the housing 9.

The invention is not limited to this particular type of spring arrangement since many other arrangements of different types of springs can be arranged to perform the same function within the scope of the invention.

In the present embodiment a single pair of springs are used in an attempt to minimise the material and the manufacturing costs. However, the invention also includes within its scope two or more laterally spaced such pairs of springs.

It will be appreciated that the balanced load position of the towing bracket adapter will occur when the compression of the upper spring is equal to compression of the lower spring.

The channel 13 has two pairs'of wide notches 24 formed one pair on each free end of its flanges. The purpose of these notches 24 is to allow the U-shaped channel 10 to move over the heads of both the securing bolts 22.

Thus, in use, the towing bracket adapter 8 is secured to a solid portion of a rear part of the towing vehicle (not shown). The towing bracket 1 is then secured to the towing bracket adapter 8 and the towed vehicle secured, by known means, to the towing bracket 1.

The marker lines on the side of the adapter are checked and, if they are outside of the acceptable limit, the weight distribution of the towed vehicle altered until the marker lines are aligned to within the acceptable limit.

The box 11 could be manufactured with a completely open front (as opposed to a mere letter box opening) and this would have the advantage of using less material and, in consequence, reduce the cost. However, such a construction would be disadvantageous as an unbalanced load could expose a narrow opening between the closure plate 18 and the box 11 and, upon sudden balancing of the load, any fingers or the like placed in the narrow opening could be severed. It is therefore desirable that the letter box type opening shown in Figure 4 is incorporated into a towing bracket adapter constructed in accordance with the present invention.

Conventionally the towing vehicle and the towed vehicle do not act as a rigid structure but can turn with respect to each other, to a limited degree, about the ball and socket joint. When the two vehicles are in motion on an uneven surface the bumping of the towed vehicle, which will happen a short time after the same bumping of the towing vehicle, can aggravate the bumping of the towing vehicle so that the occupants of the towing vehicle experience travel sickness. Even if both vehicles are double-axled occupants of the towing vehicle can still experience travel sickness.

In the present invention the bumping is transmitted from the towed vehicle to the towing vehicle through a mechanical damping mechanism. Hence, any sudden vertical movement of the towed vehicle will be substantially absorbed by the damping mechanism and comparatively little vertical movement transmitted to the towing vehicle. Clearly then, as the towing vehicle experiences a smoother ride than hitherto, the occupants of the towing vehicle and especially rear seat occupants will experience a much reduced level of travel sickness.

It will also be appreciated that any sudden vertical movement of the towing vehicle will also be absorbed by the damping mechanism and comparatively little vertical movement transmitted to the towed vehicle. This will, of course, have the effect that the towed vehicle, and any occupants thereof, will experience a smoother ride than hitherto. Thus, in this manner, horses travelling in a horsebox, or sheep travelling in a trailer, will arrive at their destination in an improved condition than hitherto.

It should be understood that the invention is not limited to the use of two opposing pairs of helical compression springs, as many other forms of arrangement are acceptable.

It should also be understood that the above embodiment refers to stainless steel only because of its resistance to rust and corrosion. It is envisaged that ordinary steel, or any other metal, or even a non-metal could be used in the construction of a towing bracket adapter in accordance with the present invention.

It should be further appreciated that the towing bracket adapter can be fitted between either the towing bracket and the towed vehicle, or, the towing bracket and the towing vehicle.

In addition, certain embodiments of the invention may be provided with a locking means whereby the vehicle connecting member can be locked in a fixed position relative to the bracket connector member. In one embodiment the lock acts upon the bracket connector so that it is maintained in a "no unbalanced load" position (as shown in Figure 2).

Such a locking means is operated by means of a simple two position switch or lever 25 located near to upon the top surface of the box section.

Also, in the event where only one pair of compression springs are used, the U-shaped bar may be constrained to move in a predetermined path so that it always remains substantially parallel to the top and bottom faces of the box section. Such an arrangement may be achieved by confining the ends of the bar within a vertically oriented channel.

The invention is not restricted to the details of the foregoing embodiment. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification and/or drawings, or to any novel one or any novel combination, of the steps of any method or process disclosed herein.

Claims

1. A towing bracket adapter comprising a vehicle connecting member, capable of being fixed to one vehicle, and a bracket connector member, capable of being fixed to a towing bracket, the adapter and bracket connector being connected together by means of a resilient mechanical damping mechanism.

2. A towing bracket adapter according to Claim 1 wherein the vehicle connecting member comprises generally a box construction.

3. A towing bracket adapter according to Claim 1 or Claim 2 wherein the bracket connector member comprises a generally U-shaped channel.

4. A towing bracket adapter according to Claim 3 wherein the U-shaped channel is located within the box construction.

5. A towing bracket adapter according to any preceding claim wherein the mechanical damping mechanism comprises an opposing spring arrangement acting between the vehicle connecting member and the bracket connecting member so that both components have a tendency to move towards a balanced or no-load position.

6. A towing bracket adapter according to any preceding claim wherein a locking means is provided whereby the vehicle connecting member can be locked in a fixed position relative to the bracket connector member.

7. A towing bracket adapter according to Claim 6 wherein the locking means operates upon the bracket connector so that it is maintained in a "no unbalanced load" position.

8. A towing bracket adapter according to Claim 7 wherein the means is operable by means of a simple twoposition switch or lever located near to (or upon) the top surface of the towing bracket adapter.

9. A towing bracket adapter substantially as hereinbefore described with reference to the accompanying drawings.