IE20080159A1

IE20080159A1 - A hitch

Info

Publication number: IE20080159A1
Application number: IE20080159A
Authority: IE
Inventors: Paul Roper; Gerry Duggan
Original assignee: Paul Roper; Gerry Duggan
Priority date: 2007-03-02
Filing date: 2008-03-03
Publication date: 2009-09-16
Also published as: IES20080158A2; WO2008107426A3; WO2008107426A2

Abstract

The present invention relates to a for coupling a trailer vehicle having a trailer brake to a towing vehicle, the hitch being mountable on the trailer vehicle and comprising a connector and a winch suitable for winding a cable thereon, the connector being attachable to the free end of the reel of cable, the connector further comprising a pair of interlocking parts, linkable by the cable, and a locking mechanism for releasably locking the pair of interlocking parts together, the pair of interlocking parts comprising a forward part comprising a towing vehicle engagement mechanism for engaging the towing vehicle in a pivotable manner and a fastening apparatus for securing the free end of the cable; and a rearward part, mountable on the trailer vehicle. The hitch further comprises a towing vehicle reverse force relay mechanism and a trailer brake linking mechanism. <Figure 3>

Description

The present invention relates to a hitch for coupling a trailer vehicle to a towing vehicle. In particular, the present invention relates to a for coupling a trailer vehicle having a trailer brake to a towing vehicle, the hitch being mountable on the trailer vehicle and comprising a connector and a winch suitable for winding a cable thereon, the connector being attachable to the free end of the reel of cable, the connector further comprising a pair of interlocking parts, linkable by the cable, and a locking mechanism for releasably locking the pair of interlocking parts together, the pair of interlocking parts comprising a forward part comprising a towing vehicle engagement mechanism for engaging the towing vehicle in a pivotable manner and a fastening apparatus for securing the free end of the cable; and a rearward part, mountable on the trailer vehicle. Such demountable hitches are well known for aiding the process of hitching a trailer vehicle to a towing vehicle In general, to attach a trailer vehicle to a towing vehicle using a standard hitch, it is necessary to reverse the towing vehicle into a position such that the tow bar of the towing vehicle is as close to the hitch of the trailer vehicle as possible, ideally positioning the tow bar below the hitch. Furthermore, preferably, the towing vehicle and trailer vehicle should be aligned with each other. Then, if necessary, the jockey wheel of the trailer vehicle is adjusted so that the hitch of the trailer vehicle is slightly above the tow bar of the towing vehicle. The hitch of the trailer vehicle is then positioned over the tow bar, and the jockey wheel is lowered so that the hitch engages the tow bar of the towing vehicle Once the hitch has engaged the tow bar, the towing vehicle and trailer vehicle are connected together in an articulated manner, the engaged tow bar and hitch forming a pivoting point. Given the number of difficulties associated with this manner of coupling a trailer vehicle and a towing vehicle, a number of two-part demountable hitches have been developed in an attempt to make the process easier. loot 53 _2_ United Kingdom Patent No. 2 252 290 describes such a hitch comprising a towing vehicle engaging section which is connected to a trailer mounted section by way of a cable fastened to the towing vehicle engaging section and which extends through a shaft comprised within the trailer mounted section. Further, a locking device is provided for locking the towing vehicle engaging section within the shaft of the trailer mounted section.

There are however a number of problems associated with the hitch of United Kingdom Patent No. 2 252 290. The locking device disclosed is very simple and is unlikely to meet the necessary safety requirements. Furthermore, no mention has been made of any form of trailer braking system and how this may be accommodated by the hitch of the invention. As trailers become more common on our roads and particularly as the trailers that are in use increase in size, the provision of trailer braking systems has become more and more important, and is required by law in many jurisdictions.

It is an object therefore of the present invention to provide a demountable hitch that integrates with the trailer braking system. It is a further object of the invention to provide a demountable hitch that is both simple and safe to operate.

Statements of Invention According to the invention there is provided a hitch for coupling a trailer vehicle having a trailer brake to a towing vehicle, the hitch being mountable on the trailer vehicle and comprising a connector and a winch suitable for winding a cable thereon, the connector being attachable to the free end of the reel of cable, the connector further comprising a pair of interlocking parts, linkable by the cable, and a locking mechanism for releasably locking the pair of interlocking parts together, the pair of interlocking parts comprising a forward part comprising a towing vehicle engagement mechanism for engaging the towing vehicle in a pivotable manner and a fastening apparatus for securing the free end of the cable; and a rearward part, mountable on the trailer vehicle Α Μ »1 -3characterised in that the forward part further comprises a towing vehicle reverse force relay mechanism; and the rearward part comprises a trailer brake linking mechanism such that, when the pair of interlocking parts are locked together, the towing vehicle reverse force relay mechanism engages the trailer brake linking mechanism, rendering the trailer brake operational on the exertion of a reverse force by the towing vehicle on the trailer vehicle.

In this way, as the towing vehicle decelerates, it will exert a force on the trailer vehicle at the point of engagement between the two vehicles. The force will act rearwardly on the trailer vehicle. This force will be relayed along the hitch of the invention by the towing vehicle reverse force relay mechanisms so that this reverse force is passed on to the trailer brake linking mechanism, thus causing the trailer braking system to operate.

In one embodiment of the invention there is provided a hitch in which the hitch further comprises a trailer brake disengagement mechanism. If the trailer vehicle attempts to reverse while towing the trailer vehicle, this will also exert a reverse force on the trailer vehicle However in this case, it is not desirable for the trailer braking system to operate. Therefore, by providing a trailer brake disengagement mechanism, the user of the hitch can choose to disengage the trailer braking system before a reversing manoeuvre.

In another embodiment of the invention there is provided a hitch in which the trailer brake disengagement mechanism comprises a towing vehicle reverse force relay disengagement mechanism. In this way a simple and effective method of disengaging the trailer braking system is provided. By disengaging the towing vehicle reverse force relay mechanism, the reverse force exerted on the trailer vehicle will not be relayed to the trailer brake linking mechanism, and consequently the breaks will not be activated during a reversing manoeuvre. -4In a further embodiment of the invention there is provided a hitch in which the towing vehicle reverse force relay mechanism comprises a push plate having a vertical face and a support extending forwardly therefrom, the support having a distal end rigidly connected to the towing vehicle engagement mechanism and a proximal end slidably mounted within the forward part of the connector. In this way, the reverse force generated by a deceleration of the towing vehicle is relayed from the towing vehicle engagement mechanism and directed along the support member to the push plate, such that the push plate slides within the forward part of the connector. The greater the force, the further the push plate will slide within the forward section, such that the push plate will in turn engage the trailer brake linking mechanism when sufficient force is exerted thereon.

In an alternative embodiment of the invention there is provided a hitch in which the push plate comprises a substantially rectangular vertical face and the support comprises a pair of side support plates extending forwardly from the side edges of the vertical face. This is a particularly effective manner of providing the push plate of the invention, as the pair of side support plates provide stability.

In one embodiment of the invention there is provided a hitch in which the towing vehicle reverse force relay disengagement mechanism comprises a brake disengaging pin slidably mounted in the forward part of the connector which is slidable to and from a brake disengaging position in which it engages the push plate, thereby limiting its movement, and a brake engaging position in which it is clear of the push plate. In this way, by sliding the brake disengaging pin into a position where it engages the push plate, the movement of the push plate will be limited or even prevented thereby preventing the relaying of the reverse force from the towing vehicle engagement mechanism to the trailer brake linking mechanism, and thereby preventing the activation of the trailer braking system.

In another embodiment of the invention there is provided a hitch in which the towing vehicle reverse force relay disengagement mechanism comprises a pair of brake disengaging pins, each of which engage one of the side support plates of the push plate while in the brake disengaging position. This is a particularly efficient and safe way of providing the towing vehicle reverse force relay disengagement mechanism. -5In a further embodiment of the invention there is provided a hitch in which the trailer brake disengagement mechanism further comprises a break disengaging lever for the operation thereof, the break disengaging lever being pivotably mounted on the forward part and being pivotably joined to a connecting link which in turn operatively engages the brake disengaging pins. In this way, a user who wishes to perform a reversing manoeuvre with towing vehicle and trailer vehicle can disengage the trailer braking system by operating moving the lever into the correct position, and to re-engage the trailer braking system once the reversing manoeuvre is completed.

In an alternative embodiment ofthe invention there is provided a hitch in which the trailer brake disengagement mechanism further comprises a wind-engaging panel comprising a substantially rectangular panel pivotably connected to a connecting link which in turn operatively engages the brake disengaging pins. In this way, the wind-engaging panel can be used to re-engage the trailer braking system automatically. Once the trailer begins to move forward while the trailer braking system are disengaged and a reasonably velocity is reached the air pressure against the wind-engaging panel caused by the movement of the trailer vehicle will cause the wind-engaging panel to pivot and consequently causing the towing vehicle reverse force relay disengagement mechanism to cease to operate thereby bringing the trailer braking system into operation. In this way, the towing vehicle and trailer vehicle will not travel very far under the dangerous conditions of disengaged trailer breaks, even if the user neglects to re-engage the trailer braking system.

In one embodiment of the invention there is provided a hitch in which the locking mechanism comprises a locking pin mounted in the forward part of the connector which is slidable to and from a locked position in which it engages a locking aperture in the rearward part of the connector and an open position in which it is clear of the locking aperture. This is a particularly effecting manner of providing a locking mechanism.

In another embodiment of the invention there is provided a hitch in which the locking mechanism comprises a pair of locking pins. The use of a pair of locking pins provides for increased safety and stability ofthe locking mechanism. -6In a further embodiment of the invention there is provided a hitch in which the locking pins work in opposing directions to each other. This provides further increases in safety and stability.

In an alternative embodiment of the invention there is provided a hitch in which the locking pins are substantially horizontally disposed. This is a particularly efficient implementation of the locking mechanism.

In one embodiment of the invention there is provided a hitch in which the locking aperture is in the side walls of the rearward part of the connector. This is again a particularly efficient implementation of the locking mechanism.

In another embodiment of the invention there is provided a hitch in which the locking aperture is a blind aperture. In this way, the locking pins will not be visible or accessible from the exterior of the hitch. This reduces the chances of third parties tampering with the hitch or locking mechanism and further, improves the appearance of the hitch.

In a further embodiment of the invention there is provided a hitch in which the locking pin is biased towards the locked position. In this way, the locking pins will automatically slide into the locked position and engage the locking apertures as soon as the forward part of the connector is correctly positioned within the rearward part of the connector.

In an alternative embodiment of the invention there is provided a hitch in which the locking pin extends from within the forward part of the connector. This is particularly advantageous as it provides extra stability and ruggedness to the locking mechanism and further allows for efficient use of space within the connector.

In one embodiment of the invention there is provided a hitch in which the forward part of the connector further comprises a locking lever for the operation of the locking pins, the lever being pivotably mounted on the forward part and being pivotably joined to a connecting rod which in turn operatively engages the locking pins. In this way, the user may unlock the locking mechanism when he wishes to demount the interlocking parts of the connector. -7In another embodiment of the invention there is provided a hitch in which the break disengaging lever and the locking lever correspond to the same lever. This provides for a particularly efficient manner of operation of the hitch of the invention, and further allows for a reduced number of components and a neater appearance.

In a further embodiment of the invention there is provided a hitch in which the hitch further comprises a securing mechanism for securing the rearward part and forward part of the connector together, the securing mechanism comprising a threaded bolt retained on the rearward part of the connector; a clasp located on the bolt and having an aperture for reception thereof and further comprising a depending ramp; an opening in the forward part of the connector for reception of the depending ramp of the clasp; and a nut mounted on the bolt for retaining the clasp thereon.

In this way, the safety of the hitch is greatly increased. Once the forward part of the connector has been inserted into the rearward part and the locking mechanism has engaged, the depending ramp clasp if the securing mechanism will rest in the opening in the forward part. The nut is then tightened on the bolt which draws the clamp back towards the head of the bolt, thereby pulling the forward part further backwards along the rearward part, by way of the depending ramp which engages the opening in the forward section. This ensures that the two parts are in complete engagement.

In an alternative embodiment of the invention there is provided a hitch in which the securing means further comprises an urging member for urging the clasp downwards. In this way the clasp will engage automatically on interlocking of the forward and rearward parts and will only require manual tightening of the nut to ensure complete interlocking.

In one embodiment of the invention there is provided a hitch in which at least one of the parts of the connector comprises a roller. In this way, the engagement of the two parts of the connector is facilitated, allowing the two parts of the connector to come together in a smooth manner, particularly when the trailer vehicle is loaded. The use of one or rollers -8in this manner reduces the chance of the forward part of the hitch becoming stuck or jammed while the parts are being brought into engagement with each other.

In one embodiment of the invention there is provided a hitch in which the forward part of the connector is a female connector. This is a particularly effective manner of implementing the forward connector.

In another embodiment of the invention there is provided a hitch in which the rearward part of the connector is a male connector. This is a particularly effective manner of implementing the rearward connector.

In a further embodiment of the invention there is provided a hitch in which the trailer brake disengagement mechanism further comprises an electronic processing means having a rotary motion sensor and a linear displacement sensor connected thereto. In this way, the electronic processing means may detect when the trailer vehicle is in reverse and can automatically disengage the trailer braking system. When the electronic processing means detects reverse motion of the trailer vehicle wheels and that there is relative motion between the forward and rearward parts of the connector causing the two parts to move closer together, it will calculate that the vehicles are reversing and that the trailer braking system should be disengaged. In this way, the trailer braking system will only be disengaged when the towing vehicle and trailer vehicle are reversing. The trailer braking system will not be disengaged if, for example, the towing vehicle and trailer vehicle were parked facing downwards on a hill causing the trailer vehicle to push forwards on the towing vehicle, which in turn would cause relative motion between the forward and rearward parts of the connector resulting in the two parts moving closer together. However as there would be no reverse motion of the wheels of the trailer vehicle, the trailer braking system would not be disengaged. Alternatively, if the towing vehicle and trailer vehicle were parked facing upwards on a hill and they started to roll backwards, there would be reverse motion of the wheels but no relative motion between the forward and rearward parts of the connector of the hitch, therefore the trailer braking system would not disengage.

In an alternative embodiment of the invention there is provided a hitch in which further comprising a barrel lock on the forward part of the connecter. In this way, the hitch -9cannot be connected to towing vehicle, thereby preventing theft of the trailer and its contents by third parties.

In one embodiment of the invention there is provided a hitch in which the securing mechanism comprises an indicator for indicating that the connector is correctly secured in place. In this way, the hitch can be locked into an inoperable state, thereby preventing theft and unauthorised use.

In another embodiment of the invention there is provided a hitch in which the locking mechanism comprises an indicator for indicating that the locking mechanism is correctly engaged. In this way, the safety of operation of the hitch is increased as it can be clearly indicated to the user that all the necessary steps have been taken to ensure complete interlocking of the parts of the hitch.

In a further embodiment of the invention there is provided a hitch in which a cable fastened to the forward part of the connector and extending rearwardly through the rearward part of the connector and engaging the winch.

In an alternative embodiment of the invention there is provided a hitch in which the cable comprises an indicator mark for indicating that a suitable level of tension has been applied to the cable. In this way, the safety of operation of the hitch is increased as it can be clearly indicated to the user that the hitch is safe to use.

In one embodiment of the invention there is provided a trailer vehicle having the hitch of the invention mounted thereon.

Detailed Description of the Invention The invention will now be more clearly understood from the following description of an embodiment thereof given by way of example only with reference to the accompanying drawings in which:Fig. 1 is a perspective view of the hitch according to the invention; -10Fig. 2 is a perspective view of the hitch according to the invention in the trailer brake disengaged position; Fig. 3 is a perspective view of the two separated parts of the connector of hitch according to the invention; Figs. 4(a), (b) and (c) are underneath plan, elevation and plan views respectively of the hitch according to the invention showing internal details in outline broken lines; Fig. 5(a) is a section of the hitch according to the invention along the line A-A in Fig. 5(b); Figs. 6(a), (b) and (c) are elevation, side elevation and plan views respectively of the hitch according to the invention; Fig. 7 is an exploded view of an alternative embodiment of the hitch according to the invention; Fig. 8(a) is a detail of the area A in Fig. 8(b) which is a perspective view of the hitch of Fig. 7; Fig. 9(a) is a detail of the area A in Fig. 9(b) which is a section along the line A-A of Fig. 9(c) which is a plan view of the hitch of Fig.7; Fig. 10(a) is a detail ofthe area A in Fig. 10(b) which is a section along the line AA of Fig. 10(c) which is a plan view of the hitch of Fig.7; Fig. 11 (a) is a detail of the area A in Fig. 11 (b) which is a section along the line AA of Fig. 11 (c) which is a plan view of the hitch of Fig.7; Fig. 12 is a perspective view of the rearward part of a further embodiment of hitch according to the invention; -11 Fig. 13 is an underneath perspective view of the forward part of the hitch according to the invention shown in Fig. 12; Fig. 14 is an underneath perspective view of the hitch according to the invention shown in Fig. 12; Fig. 15(a) is a plan view of the hitch of Fig.12, Fig. 15(d) is a section along the line A-A of Fig. 15(a), Fig. 15(b) is a detail of the area B in Fig. 15(d); Fig.15(c) is a detail of the area C in Fig. 15(d); Fig. 16 is a perspective view of the two parts of the hitch according to the invention of Fig. 12; and Fig. 17 is a perspective view of the hitch according to the invention mounted on a trailer.

Referring to the drawings, and initially to Figs. 1 to 6 thereof, there is shown a hitch indicated generally by the reference numeral 100, comprising a connector 102 and a winch 104, the connector comprising a pair of interlocking parts, a forward part 106 and a rearward part 108. The forward part 106 comprises a towing vehicle engagement mechanism 22, which comprises a standard tow ball socket for engagement with a tow ball (not shown) mounted on the rear of a towing vehicle (not shown).

The winch 104 and rearward part 108 are mounted on a base 7. The rearward part 108 comprises a male connector formed by a substantially rectangular hollow tube having two side walls 10,11 and a top plate 8. The base 7 of the hitch forms the base of the tube. The top plate 8 comprises a substantially rectangular recess 110 extending forwardly from the back of the top plate 8, which recess mounts a securing mechanism comprising a threaded bolt 45 inserted through an aperture in an end plate 9 and running parallel to the top plate 8; a clasp 46 fitted on the threaded bolt 45, a nut 47 fitted on the bolt 45 below the clasp 46. The forward end of the clasp comprises a projecting lip 115 from which descends a ramp 116. The rearward part further comprises a trailer brake link mechanism comprising a pair of braking push rods 27 and brake link rods 113. The braking push rods 27 are supported at their proximal end by a brake push -12rod guide 12 which mounted on the base 7 and at the their distal end by a guide taper 1. The brake push rods 27 further engage suitable through-holes in the end plate 9. Each brake push rod 27 comprises a through-bore normal to their length for reception of a bolt 109 which further passes through an oblong aperture 111 adjacent the top of a brake link rod 113. The brake link rod 113 is pivotally mounted on the base 7 and extends downwardly below the plate for engagement with the trailer braking system (not shown). The brake link rod further comprises an aperture at its distal end for connecting to the trailer braking system.

The forward part 106 comprises a female connector formed by an inverted channel 6 comprising a pair of side support plates 116, 118 and a covering plate 120. The forward part further comprises a towing vehicle reverse force relay mechanism comprising a braking plate 24, push plate 21 and braking block 23. The towing vehicle reverse force relay mechanism is rigidly secured to the towing vehicle engagement mechanism 22 by way of a pair of bolts 19 and accompanying washers 18 and nuts 20.

The forward part further comprises a locking mechanism comprising locking pins 36.

The forward part 106 further comprises a lever 42 which functions to operate the locking mechanism and trailer brake disengagement mechanism. The trailer brake disengagement mechanism further comprises a wind-engaging panel 62 is pivotably mounted below the lever on the forward part 106 and is operatively connected to the trailer brake disengaging pins 49 within the lock casing 35 by way of link rods 55.

The engagement between the forward part 106 and the rearward part 108 comprises a taper lock so that increased engagement between the interlocking parts can be achieved. Additionally, the rear of the forward part is tapered so as to better facilitate engagement of the two parts.

Referring now to Figs. 7 to 11 inclusive, in which like parts have been given the same reference numerals as before, there is shown an alternative embodiment of hitch comprising an alternative implementation of securing means. The alternative implementation further comprises a retaining member 112 formed on the top plate 8 of the rearward part of the connector. The retaining member 112 comprises a slot 114 at it -13sbase for engagement with the clasp 46. Further the retaining member 112 comprises a downward acting compression spring 90 which will act on the clasp 46 in use.

The remaining components of this embodiment are identical to the previous embodiment, therefore both embodiments will be more clearly understood with reference to Fig. 7 The forward part further comprises a locking mechanism comprising a lock casing 35, slotted plate 52 and locking pins 36. The locking mechanism is located within the inverted channel 6 and is secured therein by way of a plurality of screws. The locking pins are horizontally mounted in the lock casing so as to be slidable into and out of the lock casing in opposing directions to each other. When extended, the locking pins extend through suitable through-holes 121 in the side support plates 116, 118 and the push plate so as to engage the locking apertures 122 in the inside of the side plates 10, 11 of the rearward part 108.

The forward part 106 further comprises a trailer brake disengagement mechanism mounted substantially within the lock casing and being operable in an integrated manner with the locking mechanism described above. The trailer brake disengagement mechanism comprises a pair of break disengaging pins mounted in the lock casing so as to be slidable into and out of the lock casing in opposing directions to each other. The brake disengaging pins are shorter in length than the locking pins and therefore do not extend all the way to the side plates 10, 11 of the rearward part but will engage brake disengaging apertures in the push plate.

Referring now to Fig. 12 to 16 inclusive, in which like parts have been given the same reference numerals as before, there is shown an alternative embodiment of hitch comprising rollers 92, 94, 96 position at the forward edges of the two side walls 10, 11 and a top plate 8 of the rearward part 108. The rollers 92 and 94 are mounted vertically on the side walls 10, 11 while the third roller 96 is mounted horizontally on the top plate 8. The rollers facilitate relative movement between the forward and rearward parts of the connector as they are brought into engagement with each other. If the sides or top of forward part hit against the rollers as the forward part is inserted into the rearward part, the rollers will rotate so as to guide the forward part into the rearward part. In the -14absence of such rollers, there is a possibility that the forward part may get stuck or jam as it was engaging the rearward part.

A base roller 98 is mounted at the base of the forward part adjacent its back end. This will allow the forward part to roll on the base 7 as it engages with the rearward part, further reducing the possibility of the forward part getting stuck, which can occur when the trailer vehicle is heavily loaded.

Referring now to Fig. 17, in which like parts have been given the same reference numerals as before, there is shown a trailer 170 mounting the hitch 100 of the invention.

In use, a user wishing to attach a trailer equipped with the hitch of the invention to a towing vehicle positions the tow bar of the towing vehicle adjacent the trailer. The user first loosens the bolt of the securing means so that the depending ramp can be lifted out of the opening in the forward part of the connector. The user then raises the lever 42 fully so as to cause the locking pins to withdraw into the lock casing which corresponds to the open position. The forward part of the connector can now be removed from the rearward part. The user then extends the cable (not shown) so that the forward part can reach the tow bar. The user then attaches the towing vehicle engaging mechanism to the tow bar in the usual manner. Once the towing vehicle engaging mechanism is secured to the tow bar, the user winches in the cable, thereby drawing the trailer towards the towing vehicle.

As the trailer approaches the towing vehicle, the forward part will begin to engage the rearward part of the connector. As the cable is winched in, eventually the forward part will be sufficiently engage to allow the locking pins engage with the locking apertures. At this time, the locking pins are moved to their locked position, either by operating the lever 42 or alternatively, the locking pins will be biased into a locked position and will therefore engage the locking apertures automatically once they are correctly aligned.

Next the user must engage the securing mechanism by ensuring that the clasp rests within the opening in the forward part which is positioned below the clasp. Then the nut is tightened so that the clasp abuts tightly against the rear edge of the opening. This ensures that the clasp will not disengage from the opening and further causes the - 15forward part further into the rearward part, thereby ensuring complete engagement of the interlocking parts. In the alternative embodiment shown in Figs 7 to 11, the lip of the clasp is positioned in the slop 114 in the retaining member 112 and is urged downwards by the compression spring 90. In this, once the clasp is correctly positioned with respect to the opening in the forward part, it will be urged downwards to engage the opening by the compressing spring 90. Fig. 9 shows the securing mechanism is the fully engaged position, wherein the nut has been tightened on the bolt, retaining the clasp in position. Fig. 10 shows the securing means once the nut has been loosened, allowing the clasp to move forward slightly. It will be noted that tightening and loosening of the nut causes very small movements of the clasp and consequently the forward part, generally in the order of millimetres. Fig. 11 shows the position of the clasp once the bolt has been loosed further such that the clasp presses up against the retaining member and the depending ramp no longer engages the opening in the forward part, allowing the forward part to the withdrawn from the rearward part.

The engagement between the forward part 106 and the rearward part 108 comprises a taper lock so that increased engagement between the interlocking parts can be achieved. The towing vehicle and trailer are now ready for normal towing operation.

This disconnection procedure simply comprises loosening the bolt so as to disengage the securing means; lifting the lever to open the locking pins and detaching the towing vehicle engagement means from the towing vehicle.

If during the course of the towing, the user wishes to carry out a reversing manoeuvre, it is necessary to disengage the trailer braking system. The trailer braking system operates in the following manner. As the vehicle decelerates, the two vehicles will tend to push towards each other. The towing vehicle reverse force relay mechanism relays or transmits this pushing force backwards along the hitch from the towing vehicle engagement mechanism. This is achieved by the push plate of the towing vehicle reverse force relay mechanism is slidably mounted within the inverted channel of the forward part. As the towing vehicle decelerates, the push plate therefore pushes backwards so as to push against the brake push rods of the trailer vehicle brake linking mechanism, thereby activating the trailer braking system. However, a reversing manoeuvre also causes a reverse force to be relayed back towards the trailer vehicle -16brake linking mechanism, which is undesirable. Therefore before a reversing manoeuvre can be performed it is necessary to ensure that the trailer braking system will not operate. This is achieved by extending the brake disengaging pins so that they engage the brake disengaging apertures in the push plate. As the brake disengaging pins are mounted within the lock casing which is, in turn, rigidly secured within the inverted channel, the push plate will then no longer be able to slide and consequently will not be able to activate the trailer braking system.

Therefore, to perform a reversing manoeuvre, the brake disengaging pins must be extended. This is done by raising the lever 42 half way, which will not affect the locking pins but will extend the locking pins. The trailer can then be reversed conveniently. In an alternative embodiment, the hitch automatically detects that the trailer is reversing and automatically causes the brake disengaging pins to be extended.

Once the reversing manoeuvre has been completed, it is necessary to re-engage the trailer braking system so that the trailer vehicle can be towed safely. This is done by lowering the lever. However, if the user neglects to re-engage the trailer braking system and begins to move forward again at a significant speed, the air pressure acting against the wind-engaging panel will push it backwards, thereby causing the locking pins to disengage and rendering the brakes operational once more.

Throughout the specification, directional terms forward, backward and like terms have been used on the basis that the front end of a trailer vehicle is the end which engages a towing vehicle and therefore the front end of the hitch is that which is closest to the towing vehicle and the rear or back end of the hitch is that which is further away from the towing vehicle.

In the specification the terms comprise, comprises, comprised and comprising or any variation thereof and the terms include, includes, included or including or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation.

The invention is not limited to the embodiment herein described, but may be varied in both construction and detail.

Claims

1. A hitch for coupling a trailer vehicle having a trailer brake to a towing vehicle, the hitch being mountable on the trailer vehicle and comprising a connector and a winch suitable for winding a cable thereon, the connector being attachable to the free end of the reel of cable, the connector further comprising a pair of interlocking parts, linkable by the cable, and a locking mechanism for releasably locking the pair of interlocking parts together, the pair of interlocking parts comprising a forward part comprising a towing vehicle engagement mechanism for engaging the towing vehicle in a pivotable manner and a fastening apparatus for securing the free end of the cable; and a rearward part, mountable on the trailer vehicle characterised in that the forward part further comprises a towing vehicle reverse force relay mechanism; and the rearward part comprises a trailer brake linking mechanism such that, when the pair of interlocking parts are locked together, the towing vehicle reverse force relay mechanism engages the trailer brake linking mechanism, rendering the trailer brake operational on the exertion of a reverse force by the towing vehicle on the trailer vehicle.

2. A hitch as claimed in claim 1 in which the hitch further comprises a trailer brake disengagement mechanism.

3. A hitch as claimed in claim 2 in which the trailer brake disengagement mechanism comprises a towing vehicle reverse force relay disengagement mechanism. -184. A hitch as claimed in any preceding claim in which the towing vehicle reverse force relay mechanism comprises a push plate having a vertical face and a support extending forwardly therefrom, the support having a distal end rigidly connected to the towing vehicle engagement mechanism and a proximal end slidably mounted within the forward part of the connector.

4. 5. A hitch as claimed in claim 4 in which the push plate comprises a substantially rectangular vertical face and the support comprises a pair of side support plates extending forwardly from the side edges of the vertical face.

5. 6. A hitch as claimed in any of claims 4 or 5 in which the towing vehicle reverse force relay disengagement mechanism comprises a brake disengaging pin slidably mounted in the forward part of the connector which is slidable to and from a brake disengaging position in which it engages the push plate, thereby limiting its movement, and a brake engaging position in which it is clear of the push plate.

6. 7. A hitch as claimed in any of claims 5 or 6 in which the towing vehicle reverse force relay disengagement mechanism comprises a pair of brake disengaging pins, each of which engage one of the side support plates of the push plate while in the brake disengaging position.

7. 8. A hitch as claimed in any of claims 6 to 7 inclusive in which the trailer brake disengagement mechanism further comprises a break disengaging lever for the operation thereof, the break disengaging lever being pivotably mounted on the forward part and being pivotably joined to a connecting link which in turn operatively engages the brake disengaging pins.

8. 9. A hitch as claimed in any of claims 6 to 8 inclusive in which the trailer brake disengagement mechanism further comprises a wind-engaging panel comprising a substantially rectangular panel pivotably connected to a connecting link which in turn operatively engages the brake disengaging pins.

9. 10. A hitch as claimed in any preceding claim in which the locking mechanism comprises a locking pin mounted in the forward part of the connector which is slidable to and - 19from a locked position in which it engages a locking aperture in the rearward part of the connector and an open position in which it is clear ofthe locking aperture.

10. 11. A hitch as claimed in claim 10 in which the locking mechanism comprises a pair of locking pins.

11. 12. A hitch as claimed in claim 11 in which the locking pins work in opposing directions to each other.

12. 13. A hitch as claimed in any of claims 10 to 12 inclusive in which the locking pins are substantially horizontally disposed.

13. 14. A hitch as claimed in claim 13 in which the locking aperture is in the side walls of the rearward part of the connector.

14. 15. A hitch as claimed in any of claims 10 to 14 inclusive in which the locking aperture is a blind aperture.

15. 16. A hitch as claimed in any of claims 10 to 15 inclusive in which the locking pin is biased towards the locked position.

16. 17. A hitch as claimed in any of claims 10 to 16 inclusive in which the locking pin extends from within the forward part of the connector.

17. 18. A hitch as claimed in any preceding claim in which the forward part of the connector further comprises a locking lever for the operation of the locking pins, the lever being pivotably mounted on the forward part and being pivotably joined to a connecting rod which in turn operatively engages the locking pins.

18. 19. A hitch as claimed in claim 8 and 18 in which the break disengaging lever and the locking lever correspond to the same lever. -2020. A hitch as claimed in any preceding claim in which the hitch further comprises a securing mechanism for securing the rearward part and forward part of the connector together, the securing mechanism comprising a threaded bolt retained on the rearward part of the connector; a clasp located on the bolt and having an aperture for reception thereof and further comprising a depending ramp; an opening in the forward part of the connector for reception of the depending ramp of the clasp; and a nut mounted on the bolt for retaining the clasp thereon.

19. 21. A hitch as claimed in claim 20 in which the securing means further comprises an urging member for urging the clasp downwards.

20. 22. A hitch as claimed in any preceding claim in which at least one of the parts of the connector comprise a roller.

21. 23. A hitch as claimed in any preceding claim in which the forward part of the connector is a female connector.

22. 24. A hitch as claimed in any preceding claim in which the rearward part of the connector is a male connector.

23. 25. A hitch as claimed in any preceding claim in which the trailer brake disengagement mechanism further comprises an electronic processing means having a rotary motion sensor and a linear displacement sensor connected thereto.

24. 26. A hitch as claimed in any preceding claim further comprising a barrel lock on the forward part of the connecter.

25. 27. A hitch as claimed in any preceding claim in which the securing mechanism comprises an indicator for indicating that the connector is correctly secured in place. -21

26. 28. A hitch as claimed in any preceding claim in which the locking mechanism comprises an indicator for indicating that the locking mechanism is correctly engaged.

27. 29. A hitch as claimed in any preceding claim comprising a cable fastened to the forward 5 part of the connector and extending rearwardly through the rearward part of the connector and engaging the winch.

28. 30. A hitch as claimed in claim 28 in which the cable comprises an indicator mark for indicating that a suitable level of tension has been applied to the cable.

29. 31. A trailer vehicle having the hitch of any preceding claim mounted thereon.