GB2275664A

GB2275664A - Towing link for road vehicles

Info

Publication number: GB2275664A
Application number: GB9304282A
Authority: GB
Inventors: Joseph Raymond Tipper
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-03
Filing date: 1993-03-03
Publication date: 1994-09-07
Also published as: GB9304282D0

Abstract

A towing link 1 for connecting towing eyes (not shown) respectively a towing and of a towed road vehicle comprises a rigid member 1 which may be adjustable in length by the telescoping of its two limbs 3 and 4. The link is fixed at the desired length by a bolt 5. At either end of the link 1 are connectors ie. snap hooks or shackles (not shown) 15 and 16 for engaging the eyes, one or both having limited axial movement within the respective limb 3 and 4 and urged by a respective spring to a limit of its movement, e.g. a fully retracted position. Fine adjustments of the length of link 1 can he made by extending the snap hooks 15, 16 out of the limbs 3, 4. <IMAGE>

Description

"TOWING LINK FOR RaxD VEHICLES" This invention relates to towing links for road vehicles generally and particularly but nat exclusively to a rigid link adapted to connect a towing eye of one road vehicle chassis to that of anather.

A disabled road road vehicle is ordinarily towed by another using a flexible link, for exanple a rope, chain or woven web, connected at its ends to respective anchorage points on each vehicle. modern road vehicles are provided with towing eyes at the front and rear for just this purpose.

Unfortunately, towing with a flexible link is far from satisfactory as such links are prone to failure in use. In particular a rope or woven strap nay fray and snap. IiXewise a chainlink might break. It is understood that not only is such failure a problem for the motorist but that it can lead to accidents occurring on the highway. Consequently, it is believed that Police forces are lobbying to have such modes of towing made illegal on motorways.

Professional recovery vehicles are fitted with relatively sophisticated towing apparatus. One such apparatus involves the lower limb of a rigid A-frare being attached to the front wheels or sub-frame of a vehicle and the apex of the frame being attached to a tow-ball or jib nsunted at the back of the recovery vehicle. Such a rigid connection between a disabled and a towing vehicle provides for a safely articulated combination. However, it will be appreciated that the provision of such apparatus is beyond the means of, and wholly impractical for, the average motorist.

It is an object of the invention to provide a towing link which nay be readily stowed in for example the boat of a road vehicle and which nay be used to provide a rigid link between two road vehicles providing at least same of the advantages of A-frame apparatus whilst being less prone to failure than flexible links.

According to the invention towing link for connecting a towing fixture of one road vehicle to that of another comprises a rigid elongate member at each end of which is mounted aa respective one of a pair of connectors adapted to engage said fixtures, with at least one of said connectors being bath telescopically itaizited to the number for limited relative axial nouetent and spring urged to one extent of its travel.

Preferably, the connectors are each telescopically mounted to a corresponding end of the elongate member with both connectors being spring urged toward one another.

Suitably, the elongate number comprises a first elongate limb telescopically received within a second elongate limb and locking means is pravided which can lock said first to said second limb at predetermined relative positions to fix the length of the member. Also, both of the iiidbs may be fabricated fran steel tubing with the outer periphery of said first limb being a close fit within the bore of the second limb. Bath liibs nay be approxinately 760 mm in length, the first limb nay be fabricated fran 25 mm square section tube or 25 mm diameter tube and the second limb may be fabricated fran 30 mm square section tube or 30 mm diameter tube respectively.

Preferably, at least one of the connectors is telescopically mounted by neans of an annular boss rigidly attached at one end of the elongate member, an elongate stud extending fran one end of the connector and a nut or welded boss attached to the free end of the stud, with the stud being a sliding fit within the annular boss and the arrangtnt providing that the stud nay move freely within the annular boss with its travel being limited at one extent by the connector and at the other extent by the nut or welded boss.

The connectors nay be shackles or snap hooks and the aforementioned locking means may consist of a bolt extending through aligned holes in the first and second limbs.

A preferred embodiment of the invention will now be described by way of non-limitative example with reference to the acssmpanying drawing, which illustrates in partial cross-section a towing link in accordance with the invention.

The towing link illustrated comprises an elongate member 1 at each end of which is telesccpiaally mounted a pair of snap hook connectors 2. The member 1 is fabricated fran a pair of elongate tubular limbs 3,4 and locking means in the form of a M12 bolt 5 and captive nut 6 welded to the lint 4.

A first limb 3 is fabricated fran a 760 mm section of 25 imi square steel tubing. At one end of limb 3 its bore is plugged by an annular steel boss 7 welded in place. At the other end, region 8 of this limb is provided with a plurality of axially aligned clearance holes 9 extending through the tube wall with these holes 9 being arranged in diamEtrically opposed pairs spaced apart along this end region 8.

SimilarLy, the second iinb 4 is fabricated fran a 760 itra section of 30 mm square section steel tubing having one end plugged by an annular steel boss 10, ie: the ends of elongate member 1 are plugged by bosses 7,10. The respective tubing of liies 3,4 is chosen so that the outer periphery of the end region 8 of limb 3 is a sliding fit within the bore of an end region 11 of lint 4.

The end region 11 of the second litb 4 is provided with diametrically opposed clearance holes 12 extending through the tube wall closely adjacent that end of the limb. OutwardLy of one of the holes 12 is welded the captive nut 6.

Elongate nember 1 is adjustable in length with the end region 8 of the first iiitb 3 being received within the corresponding end region 10 of the second limb 4 and being slidable relative to one another. The lints are lockable at pre-defined relative positions by aligning the holes 12 in the limb 4 with a desired pair of holes 9 in the other limb 3 and then passing the bolt 5 through these aligned holes 9,12 so that it mates with the nut 6.

Each snap hook connector 2 is telescopically mounted in like manner to a free end of the respective elongate liSb 3,4. To avoid repetition only the mounting of a first of these hooks 2 at the free end region 13 of limb 4 will be described. This snap hook connector 2 has a hooked portion 14 extending fran side limb 15. Ingress and egress fran the hook is blocked by a snap shut latch piece 16 which is hinged at one end to base 17 of the connector 2 and which is spring urged against end face 18 of the hook.

Extending fran the base 17 of the connector 2 is an elongate cylindrical stud 19 which has a free end portion 20 adapted to receive a nut or boss 21 which can be welded thereto. The stud 19 is a sliding fit in the bore 22 extending through the annular boss 10 and is placed in that position prior to the fixing thereto of the nut or welded boss 21. Disposed on the stud 19 between the annular boss 10 and the nut or welded boss 21 is a coiled spring 23 which spring urges the hooked portion 14 toward the elongate member 1 so that when nat in use it is held at one extent of its travel.

In use, a towing car is backed up toward a disabled vehicle to a distance therebetween determined by the adjusted length of the member 1. A first of the connectors 2 is snapped on to a towing eye of a first of the vehicles. The second connector 2 can then be aligned with and snapped on to a towing eye of the second vehicle. It will be appreciated that this last operation will benefit fram the extension in the effective length of the towing link permissible by the telescopic mounting of the hooks 2.

This enbodient also provides advantages during towing of the vehicle.

It will be understood that with flexible links it is necessary to take up slack in the rope, etc. before the disabled vehicle moves. In a similar fashion towing of a vehicle with this embodiment requires that both connectors 2 fully compress springs 23 before movement of the towed vehicle is effected ie: the towing vehicle will move first. This is particularly advantageous because it should lead to reduced loading of the vehicle clutch as it is engaged with the engine. To understand fully this proposition it should be rettertbered that the rolling resistance of any body is at a maximum when it is at rest. Consequently, if two vehicles mave off together the rrraximrm frictional force possible nist be avercame. However, if a first vehicle is already rolling then less force is required to get them both going. It should be noted that this is an advantage that existing A-frames do nat facilitate.

Although snap hook connectors are used in this embodiment it will be appreciated that other suitable connectors may be used, for example shackles. Also, any suitable sized and shaped steel tubing may be used for the limbs 3,4.

Claims

CLAIMS:

1. A towing link for connecting a towing fixture of one road vehicle to that of another comprising a rigid elongate number at each end of which is mounted a respective one of a pair of connectors adapted to engage said fixtures, with at least one of said connectors being both telescopically mounted to the member for limited relative axial movement and spring urged to one extent of its travel.

2. A towing link in accordance with claim 1, in which the connectors are each telescopically mounted to a corresponding end of the elongate member with both connectors being spring urged toward one another.

3. A towing link in accordance with claim 1 or claim 2, in which the elongate netter comprises a first elongate limb telescopically received within a second elongate iijb and wherein locking means is provided which can lock said first to said second limb at predetermined relative positions to fix the length of the member.

4. A towing link in accordance with claim 3, in which both of the limbs are fabricated fran steel tubing and the outer periphery of said first limb is a close fit within the bore of the second limb.

5. A towing link in accordance with claim 4, in which both limbs are approximately 760 ztin in length, the first iib is fabricated fran 25 mm square section tube or 25 mm diameter tube and the second limb is fabricated from 30 mn square section tube or 30 mm diameter tube respectively.

6. A towing link in accordance with any one of the preceding claims, in which at least one of the connectors is telescopically mounted by means of an annular boss rigidly attached at one end of the elongate ititber, an elongate stud extending fran one end of the connector and a nut attached to the free end of the stud, with the stud being a sliding fit within the annular boss and the arrangement providing that the stud may more freely within the boss with its travel being limited at one extent by the connector and at the other extent by the nut.

7. A towing link in accordance with any one of the preceding claims, in which the connectors are shackles.

8. A towing link in accordance with any one of claims 1 to 6, in with the connectors are snap hooks.

9. A towing link constructed and arranged substantially as hereinbefore described and as illustrated in the accompanying drawing.