AU668388B2

AU668388B2 - Improved towing hitch

Info

Publication number: AU668388B2
Application number: AU38380/93A
Authority: AU
Inventors: John Richard Franke
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-05-04
Filing date: 1993-05-04
Publication date: 1996-05-02
Anticipated expiration: 2013-05-04
Also published as: AU3838093A

Description

i 6 83'1al -1- P/00/0011 Regulation 32

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT rs Iq t o 1 II I I I I we t ii I l I 4 t r 1 111 I to t 111t tI SLtL ¢tt

ORIGINAL

Name of Applicant: Actual inventor: Address for service JOHN RICHARD FRANKE JOHN RICHARD FRANKE in Australia: CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia Invention Title: IMPROVED TOWING HITCH Details of Associated Provisional Application: PL 2253 filing date 4 May 1992 The following statement is a full description of this invention, including the best method of performing it known to us Q_ 1^_^~_I1I_/LIICIII-~_LI-I~JIXI~ iil--. i -2- The present invention relates to a towing hitch and more particularly to an improved towing hitch suitable for use in towing trailers and the like behind vehicles (usually four wheel drive vehicles) in off-road situations. The invention is also useful in towing agricultural implements particularly over undulating terrain.

The most popular conventional towing hitch for domestic vehicles, including offroad or four wheel drive vehicles, is a ball and socket type hitch. Whilst this conventional arrangement is generally satisfactory for road use it has been found unsatisfactory over rugged terrain due to the limitations of angular movement between the ball and the socket.

For example, because the ball has a neck portion for mounting the ball on a tow bar goose-neck of the towing vehicle the amount of angular movement between the socket and ::ball is limited and in most cases only allows about 150 up and down angular movement, or tilting movement, of the trailer relative to the towing vehicle. This amount of up and o down or tilting movement is restricted in a turning arc of about 1800, that is, 90' off-centre 0 0 in each sideways direction. In the event that these limitations are exceeded, tremendous 15 strain is placed on the towing hitch which can result in fracturing of components and/or the trailer can cause the towing vehicle to overturn.

S°."It will be readily appreciated by persons who have towed trilers over rugged terrain 0 with existing hitch arrangements that much care must be taken to ensure that the critical angle between the towing vehicle and the trailer is not exceeded. This means that often the terrain cannot be negotiated or if attempted the towing and towed vehicles get into orientations which prevents the vehicles proceeding with the result that the trailer may have to be unloaded and disconnected from the towing vehicle in order to rectify the situation.

In view of the above, it is an object of the present invention to provide an improved towing hitch which allows a wider range of relative angular displacements between towing ps31/10484 May 4, 1993 -3and towed vehicle to thereby overcome one or more of the disadvantages of prior art devices.

Accordingly the invention provides a towing hitch comprising a first member for connection to a towing vehicle and a second member for connection to a towed vehicle, said first and second members being joined by a universal joint, said universal joint comprising a first U-shaped bracket, fixed to said first member and supporting a first pivot shaft which extends between the free ends thereof to form a closed loop, and a second U-shaped bracket fixed to said second member and supporting a further pivot shaft which extends between the free ends thereof to form another closed loop, said closed loops being interconnected one through the other and said pivot shafts being rotationally supported in a joining block at spaced locations, with thei r i in mutually perpendicular directions, at least one of said pivot pins being readily removable to allow separation of said joint.

On particular embodiment will now be described with reference to the S 15 accompanying drawings wherein: Figure 1 is a perspective side view of a towing hitch according to the invention: and Figure 2 is a side elevation partly in section of the towing hitch shown in Figure 1.

S 20 The towing hitch consists essentially of a solid block 10 formed of highly compressed plastics material which is in the shape of a rectangular cuboid. The block 10 has two holes (not shown) therethrough which form bores to accommodate shafts 11 and 12 respectively. The holes are spaced apart and extend in directions which are mutually perpendicular. In the embodiment shown the shaft 11 extends in a vertical direction and is spaced to the forward end of the block 10 relative to the shaft 12 which extends in a horizontal direction and is towards the rearward end of the block A structure 13 which is at the forward end of a trailer draw-bar provides a mounting arrangement for a U-shaped bracket 14 which connects the towed vehicle to the block 10. The U-shaped bracket 14 is welded to the forward nld of shaft which is adapted to slide within bore 16 within the structure 13. A locking nut 17 on the rearward end of shaft 15 prevents withdrawal of the shaft 15 and a pin (not shown) through hole 18 T 1 ps:g:#1O484.rs 1 Febrmay 1996 k41 r Fti Y~ r or o or a rr rr ic ro r or r O r rrie r -4in the locking nut 17 prevents the nut from inadvertently winding off the shaft 15. A pair of springs 19 and 20, respectively, bias the shaft 15 to a neutral position when no load is applied to the towing hitch.

The U-shaped bracket 14 extends over the block 10 as shown and shaft 11 extends through suitable apertures adjacent the free ends of the bracket 14. The shaft 11 may be a bolt which is locked in position by a nut 21 on the bottom end thereof or may be some other suitable arrangement whereby the shaft 11 is securely retained in position.

A similar arrangement exists on the rearward end of a hitch tongue 22 which is the tow bar of a vehicle (not shown). Whilst the shaft 11 extends in a vertical direction, the 10 shaft 12 is horizontal and a further U-shaped bracket 23 at the rearward end of hitch tongue 22 extends over the block 10 and is retained in position by the shaft 12. The shaft 12 has a locking pin 24 to prevent unwarranted removal of the shaft 12. The U-shaped bracket 23 is welded to the rearward end of hitch tongue 22.

As is shown more clearly in Figure 2, the hitch tongue 22 is accommodated in a 1.5 socket arrangement at the tow bar of the vehicle and may be retained in position by a further locking pin or shaft It should be evident to persons skilled in the art that the t~wing hitch according to the above described embodiment provides considerable advantage over known ball and socket towing hitches, for example. The block 10 is able to pivot through more than 900 in either horizontal direction on shaft 11 and therefore the trailer is able to theoretically reach an orientation where it is more than 90' out of direction with the towing vehicle.

Likewise, the block 10 is able to pivot vertically in either direction more than 90' about the shaft 12. The broken lines in Figure 2 show the orientation of the towing hitch as the towed vehicle tends to move down an incline relative to the towing vehicle.

ps3l/104844 May 4, 1993 i i'! ;ul i~~ ii Thus for off-road situations where a four-wheel drive vehicle, for example, may be towing a trailer through rugged terrain such as over and through dried out river beds and creek beds, it is possible for the trailer to tilt sideways substantially relative to the towing vehicle as well as to tilt in a fore and aft direction. This wide ranging angular displacement between the towing and towed vehicles enables the trailer to be pulled through terrain which could not be encountered with existing arrangements.

It will be evident to persons skilled in the art that the invention is not limited to the particular embodiment described by example hereinabove. For example, the block 10 and the brackets 14 and 23 may take many differing forms provided the final result is a universal joint having a range of movements similar to that shown above. It should be noted that since the shaft 11 passes through the closed loop formed by the bracket 23 and shaft 12 and since likewise, the shaft 12 passes through the closed loop formed by the bracket 14 and shaft 11, the connection remains intact even in the unlikely event that the block 10 disintegrates. Thus, from a safety angle the towing hitch of the present invention 15 has considerable advantages.

i4 5 i f, S i t4 4 4 I c S I I I I t Q it ps31/10484 May 4, 1993 i.

Claims

1. A towing hitch comprising a first member for connection to a towing vehicle and a second member for connection to a towed vehicle, said first and second members being joined by a universal joint, said universal joint comprising a first U-shaped bracket, fixed to said first member and supporting a first pivot shaft which extends between the free ends thereof to form a closed loop, and a second U- shaped bracket fixed to said second member and supporting a further pivot shaft which extends between the free ends thereof to form another closed loop, said closed loops being interconnected one through the other and said pivot shafts being teS rotationally supported in a joining block at spaced locations, with theiraxis in mutually perpendicular directions, at least one of said pivot pins being readily removable to allow separation of said joint.

2. A towing hitch according to claim 1, wherein said joining block has I a first bore extending therethrough to receive said further pivot shaft which is a removable shaft, whereby said second member is disconnectable from said block, lft and a second bore spaced from said first bore and arranged axially in a direction perpendicular to said first bore for receiving said first pivot shaft.

3. A towing hitch according to claim 2, wherein said joining block is in the form of a rectangular cuboid.

4. A towing hitch according to any one of the preceding claims wherein said second member comprises a rod which passes through a suitable bore of a i' mounting block on said towed vehicle, said rod being capable of fore and aft reciprocating motion against a spring bias so as to absorb forces transmitted between said towing and towed vehicles, and said rod also being capable of rotational motion in said mounting block. i II i pig:#104 4.s 1 Fcbnay 1996 L^^6 -7- A towing hitch according to claim 4 wherein said first member is a rectangular section shaft adapted for rigid connection to said towing vehicle.

6. A towing hitch substantially as hereinbefore described with reference to the accompanying drawings. DATED: 1 February 1996 CARTER SMITH BEADLE Patent Attorneys for the Applicant: JOHN RICHARD FRANKE it i I g:#1484.= I Fcbxuay 1996 A t L ;i- ABSTRACT A towing hitch comprises a first member (22) for connection to a towing vehicle and a second member (15) for connection to a towed vehicle. The members are interconnected by a universal joint comprising a block (10) and U-shaped members (23) and (14) which are connected to the ends of the first and second members respectively. A removable shaft (11) facilitates disconnection of the joint. The second member comprises a rod mounted for spring biased reciprocating movement in a mounting block (13) on the towed vehicle and the first member (22) comprises a shaft rigidly attached to the towing vehicle. 1* II It 44 4; *4'4 'li ps 3 10 4 84 May 4, 1993 iI