WO2007091222A1

WO2007091222A1 - Tow hitch

Info

Publication number: WO2007091222A1
Application number: PCT/IB2007/050433
Authority: WO
Inventors: Jakobus Nikolaas Steenkamp; Allan Steenkamp
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-02-10
Filing date: 2007-02-09
Publication date: 2007-08-16
Anticipated expiration: 2008-08-10
Also published as: WO2007091222B1

Abstract

A method and apparatus are provided for attaching an accessory (12,70) to a vehicle by inserting a spigot formation (30) that is attached to the accessory, into a complemental socket (18) that is defined on the vehicle and locking the spigot formation in position within the socket. The invention includes connecting the accessory to the vehicle electrically at the same time as receiving the spigot in the recess and further includes connecting the spigot formation to the accessory via an assembled ball-and-socket joint (44).

Description

TOW HITCH

FIELD OF THE INVENTION

THIS INVENTION relates to hitches for towing trailers behind vehicles. In particular, the invention relates to apparatus and a method for attaching an accessory to a vehicle.

BACKGROUND TO THE INVENTION

In order to enable a vehicle to tow a trailer, the vehicle is typically provided with a tow bar in the form of an angled protuberance that extends form the rear of the vehicle and is angled upwardly, with a ball-shaped end formation.

Further, the vehicle is typically provided with a standardised socket adjacent the tow bar, from which electricity can be supplied to the trailer, e.g. to power its lights.

These tow bars and sockets are typically permanently installed and protrude from the rear of vehicles.

When a trailer is to be hitched to the vehicle, the ball formation of the tow bar is received inside a socket underneath a hitch attachment of the trailer, in order to allow the ball to be held inside the socket, a locking mechanism has to be released before the ball can enter the socket, where after it must be engaged again.

These steps have to be performed whiie manoeuvring the trailer and are cumbersome and typically uncomfortable. Once the trailer is mechanically hitched, its electrical system is attached to the vehicle by inserting a plug from the trailer into the vehicle's socket. Additional safety is typically provided by engaging a chain, attached to the trailer, with the hook formation of the tow bar, to keep the trailer attached to the tow bar in the event that the ball formation is unintentionally released from the socket. The hitch attachment of the trailer can be removed by any person and if security against theft is required, an additional chain and padlock, or like locking mechanism is required.

The ball formation is typically exposed when not in use and is not lubricated, so that there is no lubrication between the ball and socket, when the trailer is hitched. Further, in order to allow for relative movement between the ball and socket, there has to be some clearance. The result is that tow hitches usually cause jerky movements of the towing vehicles and cause noise.

Further, the protrusion of the tow bars behind vehicles is unsightly and often causes discomfort or even injury of persons in the vicinity of vehicles or damage to other vehicles. Attempts have been made to address these disadvantages, by providing tow bars that are removable and/or that can fold away. However, these tow bars require operations that are cumbersome and often uncomfortable to engage the tow bars for use and to stow them away. Further, even when the mechanical tow bars have been folded away or removed, the electrical towing sockets of these vehicles still protrude behind the vehicles.

It is an object of the present invention to provide for convenient hitching of trailers to vehicles in a single movement, preferably overcoming the disadvantages of known tow bars set out herein above. BRIEF DESCRIPTION QF THE INVENTION

According to a first aspect of the present invention there is provided apparatus for attaching an accessory to a vehicle, said apparatus comprising; a casing that is mountable on the vehicle and that defines a socket; a spigot formation that extends from the accessory and that is complemental in shape to the socket; and a detent, configured to retain the spigot selectively inside the recess; wherein said apparatus further comprises electrical connectors disposed within the socket and complementa! electrical connectors disposed on the spigot formation, so that the electrical connectors are connected when the spigot formation is inserted into the socket.

The detent may be biassed, e.g. by a spring, to allow it to be clipped into the recess. The detent may be attached to the socket and one edge of the detent may be receivable in a recess defined on the spigot formation. The apparatus may further include a release mechanism for releasing clipping engagement of the detent with the recess.

The accessory may be a trailer, a load box, a luggage carrier, a bicycle carrier, or the like. When the accessory is a trailer the spigot formation may be attachable to the rest of the trailer via pivoting attachment, such as an assembled ball-and-socket joint, which may be lubricated and sealed. The casing may define a mechanical retaining formation and the spigot may define a formation that is complemental to the retaining formation and that is configured to be connected to the retaining formation when the spigot is received in the recess. The detent may be configured to retain the complemental formation and the mechanical retaining formation connected together, selectively.

The apparatus may include a lock that is configured selectively to retain the detent in a position in which it retains the complementai formation and the mechanical retaining formation connected together.

The apparatus may includes a lock that is configured to iock the spigot formation into attachment when it is inserted into the socket, so that the lock has to be opened, e.g. with a key, to release the spigot formation from the socket.

The casing may be mountable on the vehicle, generally behind a vehicle body part, such as behind or below a bumper of the vehicle, so that only the aperture of the socket is visible on the vehicle bumper, when the accessory is not attached to the vehicle.

According to another aspect of the present invention there is provided a method of attaching an accessory to a vehicle, said method comprising inserting a spigot formation that is attached to the accessory, into a complemental socket that is defined on the vehicle and locking the spigot formation in position within the socket, wherein the method includes connecting the accessory to the vehicle electrically at the same time as receiving the spigot in the recess.

The spigot formation may be retained in the socket by way of a displaceable detent and/or may be locked into the socket.

The method may include pivotally attaching the spigot formation to a traiier by way of an assembled ball-and-socket joint as described above.

BRIEF DESCRiPTION QF THE DRAWINGS For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of non- limiting example, to the accompanying drawings in which:

Figure 1 is a three dimensional view of the apparatus of a first embodiment of the present invention, as seen from the rear left;

Figure 2 is a three dimensional view of the apparatus of Figure 1 as seen from the rear right;

Figure 3 is a three dimensional view of the apparatus of Figure 1 as seen from the right front; Figure 4 is a three dimensional view of an accessory of a second embodiment of the present invention, as seen from the rear left;

Figure 5 shows a sectional side view of apparatus of a third embodiment of the present invention, before being hitched;

Figure 6 shows the apparatus of Figure 5 partly hitched; Figure 7 shows the apparatus of Figure 5 fuliy hitched; Figure 8 shows a sectional rear view of the apparatus of Figure 7, taken at ViII-VIII;

Figure 9 shows a sectional side view of apparatus of a fourth embodiment of the present invention;

Figure 10 shows a diagrammatic plan view of the apparatus of Figure 9 partly hitched;

Figure 11 shows a diagrammatic plan view of the apparatus of Figure 9 fully hitched; Figure 12 shows a sectional side view of the apparatus of a fourth embodiment of the present invention; and

Figure 13 shows a side elevation of the accessory of the apparatus of Figure 12.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, towing apparatus in accordance with the present invention that forms part of a vehicle is generally indicated by reference numeral 10, whereas towing apparatus in accordance with the present invention that forms part of an accessory in the form of a trailer, is generally indicated by reference numeral 12. Similar features in different embodiments of the invention are indicated by the same reference numerals, where practical.

Referring firstly to Figures 1 to 3, the apparatus 10 on the vehicle inciudes a bracket 14 that can be bolted to structural parts of the vehicle, inside or below the bumper of the vehicle. A hollow casing or socket formation 16 extends from the bracket 14 and defines in internal socket with a square or any other non- round cross-sectional profile. A detent in the form of a locking clip 20 is pivotally attached to the socket formation 16 near its front end and a locking edge 22 of the clip is held downwardly by an extension coil spring 24. A release for the clip 20 is provided in the form of a ring 26 that is attached to the clip at a corner opposite from the locking edge 22, so that the clip is pivoted against the bias of the spring 24 and the locking edge is lifted, when the release ring 26 is pulled downwardly.

An electrical connector (not shown) that defines six contact sockets, is provided inside the socket 18 and is connected to electrical systems of the vehicle via wires 28. The connector is mounted in a lining of rubber or other suitable material to absorb mechanical shocks that may be transferred to the socket 18.

It is to be appreciated that ail of the apparatus 10 is preferably permanently installed inside the vehicle's bumper, so that only a square aperture is visible in the bumper, which leads to the socket 18. A removable cover can be provided for closing this aperture when not in use and a protective border of wear resistant material such as rubber or plastic can be provided on the bumper, around the aperture, to prevent damage to the bumper during hitching.

The apparatus 12 on the trailer includes a spigot formation 30 with a square cross-sectional profile that is complemental to the profile of the socket 18. A lip 32 extends from the top edge of the leading end of the spigot 30 and a recess in the form of a groove 34 is defined in the top of the lip, in which the locking edge 22 can fit. An electrical connector 36 (such as a male socket) is provided at the leading end of the spigot, with six electrical contact prongs, that are complemental to the contact sockets in the connector within the socket 18. An upper edge of the spigot 30 is recessed so that electrical wires 38 can extend from the trailer, along the recess and to the connector 36.

The rear end or base of the spigot 30 is fixedly attached to a bracket plate 40 that is in turn bolted to an outer housing 42 of a ball-and-socket joint 44. The joint 44 is internally lubricated with grease and is covered by a boot 46. An attachment shank 48 extends from the bail side of the joint 44 and is connectable to the rest of the trailer with a lock nut 50.

In use, when the trailer is to be hitched to the vehicle, the trailer is manoeuvred so that the spigot 30 slides snugly into the socket 18 until the locking edge 22 slides over the lip 32 and locks into the groove 34 in a clipping manner, under the bias of the spring. The spigot 30 is now locked inside the socket 18, so that the trailer is hitched to the vehicle. At the same time, the connector 36 makes electrical contact with the connector inside the socket 18, so that the wires 28 of the vehicle are electrically connected to the wires 38 of the trailer.

The trailer can now be towed behind the vehicle with the mechanical towing forces transferred via the apparatus 10 and 12, but not via the electrical connectors while the ball-and-socket joint 44 allows the trailer to pivot relative to the spigot 30 that is locked to the apparatus 10 of the vehicle. The lubricating grease inside the boot 46 allows smooth functioning of the joint 44 and inhibits wear and tear.

When the trailer is to be unhitched, the release ring 26 is pulled downwardly to pivot the clip 20 and release the locking edge 22 from the groove 34, so that the spigot 30 can be withdrawn from the socket 18. It is to be appreciated that operation of the apparatus 10 and 12 requires a single movement to connect the trailer to the vehicle mechanically and electrically and lock it in place automatically. Once the ring 26 is pulled downwards, another single (opposite) movement is required to disconnect the trailer from the vehicle.

in addition, a round steel bar (not shown) can be provided that is held adjacent the socket formation 16 and that can pass through apertures in the wails of the socket formation and in the spigot 30, to lock the spigot in position. The bar can be configured to be axially disptaceable by a spring, to engage it and by a solenoid to disengage it.

Referring to Figure 4, if the vehicle is to be used to tow a conventional trailer, a conventional ball 52 with a gooseneck 54 can be attached to the spigot 30 by bolting it to the bracket plate 40, thus allowing conventional trailers to be hitched to the vehicle by insertion of the spigot into the socket 18 with the same ease and convenience as described herein above. In the event where the accessories to be attached to the vehicle are not trailers, an unlimited variety of accessories can be bolted onto the bracket piate 40 instead of the housing 42 of the ball-and-socket joint 44. Typical accessories would include bicycle racks, luggage racks, spare wheels, load boxes, etc.

Referring to Figures 5 to 8, apparatus in accordance with the third embodiment of the present invention includes apparatus 10 mounted on a vehicle, functionaily similar to that described with reference to Figures 1 to 3. However, the third embodiment of the invention is intended to attach an accessory, generally indicated by reference numeral 70, to the apparatus 10 to provide a conventional towing ball 52 and gooseneck 54.

The apparatus 10 includes a casing 56 defining a socket 18 with a rounded shape at its closed end and with a mechanical retaining formation in the form of a load bearing recess 58 in its bottom. At the top of the recess 18, the apparatus 10 includes a detent in the form of a latch 60 that can slide vertically in lateral grooves 62 defined in the side walls of the casing 56 (shown in broken lines in Figures 5 and 6). The latch has two protuberances or pins 64 that extend rearwards, towards the opening of the socket. In the bottom of the recess 18, the casing defines a number of electrical contact sockets 66 that are electrically connected to the electrical systems of the vehicle. The apparatus 10 is preferably entirely recessed inside a bumper or like part of the vehicle's body, similar to the socket formation shown in Figures 1 to 3. Further, the casing 56 is connected to the chassis 68 of the vehicle in a manner that allows the transfer of towing loads to the vehicle chassis.

The accessory 70 includes an elongate spigot 30 that is complemental in shape to the inside of the socket 18 with a rounded front end. At the rear (base) of the spigot 30, a ball 52 and gooseneck 54 are attached to it in any suitably sturdy manner, e.g. by being bolted. Two inwardly pointing rails 72 are welded to the top of the spigot 30 and a lock 74 is held between the rails so that it can slide longitudinally backwards and forwards, but is held captive by the rails so that it cannot be removed from the spigot. The lock 74 defines recesses 76 at its front in which the pins 64 can be received in a locking manner and from which they can be released by unlocking the lock, e.g. with a key inserted into a keyhole 78.

The spigot 30 has a load bearing protuberance that extends from its bottom and that is complementai in shape to the recess 58 in the socket 18. Further, electrical connectors 82 extend from the underside of the spigot, complemental to the electrical sockets 66 in the socket 18.

In use, to attach (hitch) the accessory 70 to the vehicle, it is tilted at an angle, with the front end pointing downwardly as shown in figure 6 and the spigot 30 is inserted into the socket 18, with the latch 60 above the spigot. Once inserted, the rear end of the accessory 70 is lowered so that the protuberance 80 nests in the recess 58 for mechanical connection of the accessory 70 to the casing 18 and thus the vehicle chassis 68 and at the same time, the electrical connectors 82 are inserted into the contact sockets 66 for electrical connection of the accessory 70 to the vehicle.

When the rear end of the accessory 70 is lowered, the latch 60 slides downwardly in its grooves 62 under gravity and once the mechanical and electrical contact between the accessory and the vehicle has been made, the lock 74 is slid forward in its rails 72 until the pins 64 are received in a locking manner in the recesses 76. The forward sliding movement of the lock 74 causes it to slide underneath an upper part of the casing 18, referred to as the bridge 84. The nesting of the lock 74 underneath the bridge 84 prevents the rear part of the spigot 30 and thus of the accessory 70 form lifting, which ensures that the mechanical and electrical connection of the accessory to the vehicle is maintained. At the same time, the grooves 62 hold the latch 60 captive to prevent it from sliding to the rear of the socket 18 and thus the lock (which is locked to the detent) is prevented from sliding rearward.

In order to ensure that mechanical loads from the accessory 70 are primarily (if not exclusively) transferred to the vehicle via the mechanical connection of the protuberance 80 to the recess 58, the connectors 82 and/or the contact sockets 66 can be mounted in rubber. The lock 74 can slide backwards and forwards and accordingly, will not transfer loads between the accessory 70 and the vehicle, other than the compression it may bear when preventing the rear of the accessory from lifting relative to the socket 18.

The use of the lock 72 adds security (against theft) and safety (against accidental disconnection) to the apparatus, as the spigot 30 can only be withdrawn from the socket 18 if the lock is released with a key.

To unhitch the accessory 70, the lock 74 is released and is slid rearward on the spigot 30 to free the pins 64, the rear of the spigot is lifted, pushing the latch 60 upwards and releasing the protuberance 80 from the recess 58 and also releasing the connectors 82 from the contact sockets 66 and the spigot is withdrawn rearwards from the recess 18.

Referring to Figures 9 to 11 , the fourth embodiment of the invention includes apparatus 10 mounted on a vehicle and an accessory 70, although the accessory is neither shown with a combined ball-and-socket joint, nor with a conventional gooseneck and ball, as shown in Figures 1 to 8. However, as mentioned above, the accessory 70 can be used with either of these configurations for hitching and towing a trailer, and/or can be used for any other type of accessory that needs to be hitched to the rear of a vehicle.

The apparatus 10 on the vehicle includes a casing 56 that is mounted on the vehicle, inside the vehicle's body or bumper 86. The casing 56 defines a recess 18 and an upper part of the casing adjacent the opening of the recess 18 forms a bridge 84, but the rear edge of the casing forms a recess 88, immediately adjacent the bridge. A mechanical retaining formation in the form of an upstanding lip 90 is defined at the bottom of the opening of the recess 18 and the upper wall of the casing is angled so that the space between the lip and the bridge 84 is generally the same as the lowest internal height of the recess near its front (to the left in Figures 9 to 11).

The accessory 70 includes a spigot 30 that has a thickness at its front that is generally equal to the lowest internal height of the recess 18, but that forms a step 92, behind which it is thinner by an amount generally equal to the height of the lip 90.

The accessory 70 and casing 56 are provided with electrical connectors 36 and contactors 66, similar to those shown Figures 5 to 8, except that instead of sockets, the contactors 66 each have a conductive plate defining an electrical contact surface. The connectors 36 and contactors 66 are connected to the electrical systems of the vehicle and to electrical systems of the accessory 70.

The accessory 70 includes a detent in the form of a lever 94 that is pivotaliy attached to the top of the spigot 30. Two pins 64 protrude to one side of the lever and are receivable in a lock 74 that is fixedly or pivotaliy mounted on top of the spigot.

In use, the accessory 70 is hitched to the vehicle by placing the lever

94 at an angle relative to the spigot 30 as shown in Figure 10 and inserting the spigot into the recess 18. In order to insert the spigot 30 into the recess 18, it is initially slid in abutment with the angled upper wall, to dear the lip 90 and once it is fully inserted, the rear end of the accessory (to the right in Figures 9 to 11 ) is iowered so that the iip is seated snugly behind the step 92 to provide a mechanical connection and so that the pins 64 make electrical contact with the contactors 66.

While the spigot 30 is inserted into the recess 18, the lever 94 remains angled relative to the spigot and this allows the end of the lever to be received in the recess 88, so that the end of the lever does not interfere with the sliding of the spigot 30 along the top wail of the recess 18, as shown in Figure 10. However, once the spigot 30 has been fully inserted and its rear end iowered, it is locked into position by pivoting the lever 94 anti-clockwise, to the longitudinally aligned position shown in Figures 9 and 11 , in which the end of the lever is slid underneath the bridge 84. The insertion of the end of the lever 94 between the spigot 30 and the bridge 84 prevents the spigot from lifting or tilting, so that the mechanical and electrical connections are maintained.

in order to prevent the lever 94 from pivoting from underneath the bridge 84, its pins 64 are received inside recesses 76 inside the lock 74, in which they are Socked, until the lock is released with a key.

in a preferred version of this embodiment of the invention, the upper wall of the casing 56 is shaped around the recess 88 to form a guide ridge, shown in

Figure 11 as a broken line numbered 96, that is configured to urge and guide the end of the lever 96 from its pivoted position to its longitudinally aligned position, as the spigot 30 is slid into the recess 18. This holds the advantage that the spigot 30 is automatically locked in position inside the socket 18, by way of the lever being positioned under the bridge 84 and being held there by the engagement of the pins 64 with the lock 74 without requiring any additional operations.

To unhitch the accessory 70 from the apparatus 10, the lock 74 is released to free the pins 64, the lever 94 is pivoted so that its end is in the recess 88 and clears the bridge 84, the rear of the spigot 30 is lifter to release the electrical connection and for the step 92 to clear the lip 90 and the spigot 30 is withdrawn from the recess 18, while sliding along the inside of the upper wall.

Referring to Figure 12, the fifth embodiment of the invention includes apparatus 10 mounted on a vehicle, almost identical to that shown in Figures 9 to 11 , with no recess defined in the bridge 84 and with slightly differently configured electrical connectors 82 and contacts 66.

The accessory 70 shown in Figures 12 and 13 has a spigot 30 and step 92 that are identical to those shown in Figures 9 to 11 , but it has a detent in the form of a tongue 98 that is mounted on top of the accessory to siide longitudinally backwards and forwards, but is prevented from moving laterally or being removed from the accessory. The lock 74 is fitter on top of the tongue 98 and is attached to the tongue to slide backwards and forwards with the tongue and its recesses faces forward, towards the tip of the tongue. A body 100 is fitted on top of the spigot 30 and is fixedly attached to the spigot, with the tongue sliding underneath a part of the body. Two pins 64 extend rearward from the body 100. In use, the accessory 70 is hitched to the vehicle by sliding the tongue 98 and iock 74 backwards so that the tip of the tongue does not protrude outside the body 100, as shown in Figure 13. The spigot is inserted into the recess 18 in the same manner as described with reference to Figures 9 to 11. Once the spigot has been so inserted, instead of pivoting a lever to form a detent between the bridge 84 and spigot 30, the tongue 98 and lock 74 are slid forward so that the tip of the tongue fills the space between the spigot 30 and the bridge 84, as shown in Figure 12. At the same time, the pins 64 are received in the recesses 76 and hold the lock 74 and tongue 98 in position relative to the body 100 and spigot 30.

To unhitch the accessory 70 from the apparatus 10, the lock 74 is released to free the pins 64, the tongue 98 and lock are slid rearward to withdraw the tip of the tongue from the recess 18 to dear the gap between the spigot 30 and the bridge 84. The rear of the spigot 30 is lifter to release the electrical connection and for the step 92 to clear the Np 90 and the spigot 30 is withdrawn from the recess

18, while sliding along the inside of the upper wall.

Claims

1. Apparatus for attaching an accessory (12,70) to a vehicle, said apparatus comprising; a casing (16,56) that is mountable on the vehicle and that defines a socket

(18); a spigot formation (30) that extends from the accessory and that is complemental in shape to the socket; and a detent (20,60,94), configured to retain the spigot selectively inside the recess; characterised in that said apparatus further comprises electrical connectors (66) disposed within the socket and complemental electrical connectors (36,82) disposed on the spigot formation, so that the electricai connectors (66,36,82) are connected when the spigot formation is inserted into the socket.

2. Apparatus as claimed in claim 1 , characterised in that said spigot (30) is attachable to an assembled ball-and-socket joint (44).

3. Apparatus as claimed in claim 1 or claim 2, characterised in that said casing (16,56) defines a mechanical retaining formation (58, 90) and said spigot (30) defines a formation (80,92) that is complementai to said retaining formation and is configured to be connected to said retaining formation when the spigot is received in the recess.

4. Apparatus as ciaimed in claim 3, characterised in that said detent

(60,94) is configured to retain said complemental formation (80,92) and said mechanical retaining formation (58, 90) connected together, selectively.

5. Apparatus as claimed n claim 4, characterised in that said apparatus includes a lock (74), configured selectively to retain said detent (60,94) in a position in which it retains said complemental formation (80,92) and said mechanical retaining formation (58, 90) connected together.

6. Apparatus as ciaimed in any one of claims 1 to 4, characterised in that said apparatus includes a lock (74) that is configured to lock the spigot formation (30) into attachment when it is inserted into the socket (18).

7. Apparatus as ciaimed in any one of the preceding claims, characterised in that said casing (16,56) may be mountabie on the vehicle, generally behind a vehicle body part (86).

8. A method of attaching an accessory (12,70) to a vehicle, said method comprising inserting a spigot formation (30) that is attached to the accessory, into a complemental socket (18) that is defined on the vehicle and locking the spigot formation in position within the socket, characterised by connecting the accessory to the vehicle electrically at the same time as receiving the spigot in the recess.

9. A method as claimed in claim 8, characterised by retaining the spigot formation (30) in the socket (18) by way of a displaceable detent.

10. A method as claimed in claim 8 or claim 9, characterised by locking the spigot formation (30) into the socket (18).

11. A method as claimed in any one of claims 8 to 10, characterised by pivotally attaching the spigot formation (30) to a trailer by way of an assembled ball- and-socket joint (44).