Abstract:
A protective device for use with a tow-bar having a towing hitch coupling. The protective device includes a substantially T-shaped member. The leg of the T is adapted to be coupled to the towing hitch coupling and the head of the T extends rearwardly of the towing vehicle past any rearwardly projecting components of the vehicle.

Description:
FIELD OF THE INVENTION 
   This invention relates to improvements to tow-bars and in particular relates to an additional component that can be used with a conventional tow-bar. 
   BACKGROUND OF THE INVENTION 
   Many vehicles such as cars and four wheel drives are these days fitted with tow-bars. 
   Conventional tow-bars comprise a bar that is mounted to the rear of the towing vehicle through a number of mounting points to distribute the towing load. The bar is a sturdy steel construction and is coupled to a towing hitch that includes an upstanding tow-ball that is adapted to fit on a towing socket that is provided on the vehicle that is to be towed. The ball and socket means of attachment is the most common means of attaching a trailer to a tow-bar. However to allow the vehicle to turn relative to the trailer it is important that there is space between the rear of the vehicle and the tow-ball, thus towing hitches have the effect of causing the tow-ball to project rearwardly of the vehicle. This rearward projection of the tow-ball is potentially hazardous both in terms of the damage that it can cause to a vehicle that may make a slow speed collision with the rear of the vehicle and the damage it does to pedestrians&#39; legs as they walk behind the vehicle and do not see the tow-ball which is comparatively close to the ground. Many pedestrians have severely bruised their shins in this manner. 
   Many towing hitches can be removed from the tow-bar by either removal of a locking pin that holds the hitches in position or unbolting the towing hitch from the bar. The problem with removing the towing hitch is that most tow-bars also include an electrical socket into which a plug from the trailer can be inserted to enable the trailer to display turning, tail and stop lights. If the towing hitch is removed from the tow-bar and a vehicle was to make a slow speed collision with a towing vehicle, the electrical socket, because it often projects rearwardly of the vehicle, takes the full impact of the load and thus is easily damaged. 
   SUMMARY OF THE INVENTION 
   It is these issues that have brought about the present invention. 
   In accordance with the present invention there is provided a protective device for use with a tow-bar having a bar and a towing hitch coupling, the protective device comprising a substantially T-shaped member whereby the leg of the T is to be coupled to the towing hitch coupling, and the head of the T extends rearwardly of the towing vehicle past any rearwardly projecting components of the vehicle. 
   The T piece preferably comprises a post welded to a metal plate with the plane of the plate perpendicular to the longitudinal axis of the post. The post including means to facilitate attachment to a tow-bar. The post is preferably of square cross-section and is adapted to be a sliding fit within the interior of a coupling bracket welded to the towing bar. Apertures are positioned across the post to accommodate a locking pin that extends through the bracket on the towing bar and through the apertures on the post of the T-shaped member. The head of the T-shaped member may be asymmetrically mounted to the post. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: 
       FIG. 1  is a schematic illustration of a conventional prior art tow-bar and towing hitch, 
       FIG. 2  is a schematic illustration of a towing bar with the towing hitch removed and replaced by a protective device in accordance with one embodiment of the invention, 
       FIG. 3  is a perspective view of the protective device, 
       FIGS. 4   a  and  4   b  show the device in two mounting positions, and 
       FIGS. 5   a  and  5   b  show the device at two different heights. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In  FIG. 1 , the conventional layout of a tow-bar T and towing hitch H is schematically illustrated. This is the prior art assembly that is frequently used on vehicle such as four wheel drive vehicles. 
   The tow-bar T of such vehicles comprises a sturdy steel bracket assembly (not shown) that is bolted to the chassis of the vehicle V in a number of spaced positions in order to distribute the towing load across the rear of the vehicle. A towing hitch H is attached to the towing bar T via a towing hitch coupling to project rearwardly of the vehicle for attachment to the trailer or the vehicle that is to be towed. The towing hitch coupling is illustrated as bracket B which is usually in the form of an elongate steel tube with a square or rectangular interior. The towing hitch H has a similarly profiled square post P that is a sliding fit within the interior of the bracket B. An aperture A extends through the walls of the bracket B and the towing hitch H and a large pin (not shown) extends through the apertures to hold the assembly together. Various means can be positioned on the end of the locking pin to prevent removal including keyed locks. 
   The projecting end of the post is then welded to an L-shaped plate L that projects rearwardly and has bolted to it a conventional tow-ball S. The distance between the tow-ball S and the rear of the vehicle V is selected to allow the vehicle to turn relative to the trailer without the trailer fouling the rear of the vehicle V. 
   Trailers are usually by law required to include a lighting system, namely tail lights, stop lights and turning lights. It is thus usual for trailers to have a plug that can be coupled to a socket E mounted on the rear of the vehicle to effect transfer of the vehicle&#39;s lighting to the trailer. The usual position of the electrical socket E is such that if the towing hitch H is removed from the tow-bar T in situations where the vehicle is not used for towing, the most rearwardly projecting component of the vehicle is the electrical socket E which leaves the socket E very vulnerable to damage especially during parking. 
   The invention as illustrated in  FIGS. 2  to  5  essentially comprise a device  10  that can replace the towing hitch H when not required to protect the electrical socket E and other componentry at the rear of the vehicle V. The device  10  is essentially a protector that is adapted to be attached to the tow-bar T in the same manner as the towing hitch H. 
   Thus, the protector  10  comprises a square shaped post  11  that is adapted to be a sliding fit within the female bracket B that is part of the tow-bar T. If the bracket B of the towing hitch H happens to not be in the form of an elongate square tube, post  11  can be modified in shape to a corresponding construction to the bracket thereby enabling coupling of the protective device  10  and bracket B. 
   The post  11  has apertures  20 ,  21  and  22  extending laterally across the post to accommodate a locking pin (not shown) in exactly the same manner shown in FIG.  1 . The post  11  is welded to a rectangular steel plate  14  and the mounting is such that the plane of the steel plate  14  is rearward of the furthest projection of the vehicle V. Thus, should a vehicle V carrying the protector  10  be involved in small contact during parking or from collision with a vehicle from the rear, the collision would occur first with the plate  14  thereby protecting the potentially vulnerable electrical socket E and rear bumper bar R of the vehicle and minimising damage to the front of the rear vehicle. 
   The size of the plate  14  is sufficient to take small impact loads and although a planar rectangular plate is illustrated in  FIG. 2  it is understood that other profiles are envisaged including plates that present a convexly curved surface. 
   In  FIGS. 3  to  5  the device  10  has a series of three pairs  20 ,  21 ,  22  of holes along the post so that as shown in  FIGS. 4   a  and  4   b  the degree of protection of the plate  14  can vary depending on which pair of holes is selected to locate the pin. 
   The plate  14  is also asymmetrically located on the post to allow, as shown in  FIGS. 5   a  and  5   b , selection of the height of the plate  14  relative to the vehicle. The device may also be coupled to the bracket B in more than one orientation as shown in  FIGS. 5   a  and  5   b  vertical inversion of the direction of the device  10  alters to the effective height of the plate  14 . 
   It is also understood that whilst the protector is preferably constructed of mild steel it can be chrome plated, painted or galvanised. The protector could also be made of reinforced plastics or reinforced fiberglass products with the inherent strength to resist low speed, low impact loads. 
   Although a locking pin is the preferred way of attaching the protector to the tow-bar it is understood that other forms of attachment are also envisaged including bolting the assembly to the tow-bar.