GB2218952A - Vehicle anti-theft apparatus - Google Patents

Abstract

An anti-theft device for vehicles which comprises a housing 28 for attachment to a structural member of the vehicle. Housing includes an annular section 27 into which can selectively be sited an elongate tubular member 1 of a length approximating to or slightly greater than the distance between housing when attached and the ground. Means are provided for locking the tubular member within the annular section of the housing. Said means preferably comprise spring urged plungers 15 whose heads 23 located in a circumferential groove 31 in the annular section 27. A key operated barrel lock 8 having a spigot 13 to prevent movement of the plungers 15 out of their engaging position. The spigot can be locked into and out of the path of the plungers 15 preventing removal of the elongate member when locked. <IMAGE>

Description

Anti-Theft ApParatus This invention relates to apparatus for inhibiting or impeding the theft of towed vehicles such as caravans, horse boxes, trailers for boats and light aircraft, and farm machinery.

Various locking devices are known for impeding the theft of towed vehicles such as caravans, these including coupling locks comprising a simulated tow ball which fits into and, on locking, fills the cup of a towing hitch to prevent normal coupling of the towbar to the towed vehicle; locking devices which immobilise the hitch mechanism of the caravan; clamps which fit over one or each wheel of a caravan to prevent rotation of the same; and a variety of forms of trailer posts which are normally set in concrete to define a permanently sited anchor for a clamp carried by the caravan.

None of the currently available anti-theft devices are effective in deterring or inhibiting a determined thief other than possibly some variations of the abovementioned trailer posts. Of the three other known devices described, the coupling and hitch immobilising devices can simply be overcome by removal of the immobilised hitch and replacement of the removed hitch with an unlocked hitch; and wheel clamps can be circumvented merely by deflating the tyres of the clamped wheels, and then moving the caravan forwardly to release them from the clamps.

Trailer posts have the inherent disadvantage that they can only protect a caravan or trailer against theft when it is sited adjacent to such a post. Thus, the caravan is not protected at, for example, temporary locations such as motorway stops and at caravan sites.

The present invention sets out to provide an alternative anti-theft device for caravans and other trailers which does not suffer from or at least overcomes some of the disadvantages referred to above.

According to the present invention there is provided an anti-theft device for towed vehicles which comprises a rigid housing for attachment to a structural member of the towed vehicle, the housing including an annular section into which can selectively be sited an elongate tubular member of a length approximating to or slightly greater than the distance between the housing, when attached, and the ground and means for locking the tubular member within the annular section of the housing.

The invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which: Figure 1 is a side elevational view of an anti-theft device in accordance with the invention; Figure 2 is an exploded view of the anti-theft device illustrated in Figure 1 showing a locking mechanism used therefor; Figures 3 and 4 are respectively side and plan views partly in section of a pin lock carrier which forms part of the device illustrated in Figure 2, Figure 4 being a section taken along line IV-IV of Figure 3; and Figure 3; Figures 5 and 6 are respectively plan and side elevational views (the latter partly in section) of a housing for receiving and holding the device illustrated in Figure 1 to 4; and Figures 7 and 8 are plan and side views of a ramp suitable for use with the anti-theft device illustrated in Figures 1 to 6.

The anti-theft device illustrated in Figures 1 and 2 of the drawings includes a tube 1 of hardened steel or other high strength material which is closed at its upper end by a cap 2 and at its lower end by a plug 3. Plug 3 has a serrated lower surface 4 and carries on its upper face a cylindrical extension 5 which fits firmly within the lower end of the tube 1.

The cap 2 is shown in section in Figure 2 and includes a central opening 6 to receive the cylindrical barrel 7 of a key-operated lock 8. Outwardly extending handles 9 are secured to the cap by any suitable means, and the cap 2 is secured to the tube 1 by grub screws 10.

A backing plate 11 of the lock 8 is screwed to the inner face of the cap 2 and is so located by means of a spacer 12 that the upper face of the barrel 7 is positioned substantially flush with the outer face of the cap 2. The lock 8 includes a locking rod 13 which can be moved towards and away from the tube 1 by a key inserted into the end face of the lock sited flush with the cap surface.

Secured to the inner circumference of the tube 1 at a position just below the lock 8 is a carrier 14 for three ball-ended spring-loaded pins 15 (only one of which is shown. The carrier 14 is illustrated in greater detail in Figures 3 and 4 and comprises an annular base 16 formed with shaped recesses 17 to receive the ends of grub screws which pass through apertures 18 formed in the tube to lock the carrier in place. The carrier 14 is formed in two parts 14a, 14b which can be drawn together by screws passing through bores 19 to trap and retain the ball-ended pins 15 therebetween. The pins 15 each have rounded ends 23 and include cylindrical end pieces 20 which protrude into and through apertures 21 and carry collars 22 between their rounded ends 23 and the cylindrical end pieces 20.The rounded ends 23 of the pins 15 protrude through suitably positioned apertures 24 formed in the tube 1 and the collars 22 are urged into contact with the tube interior by compression springs 25.

Thus, the rounded ends 23 of the pins 15 stand proud from the outer surface of the tube but can be moved inwardly to positions flush with the tube surface against the action of the springs 25.

The lock 8 is so positioned that the locking rod 13 is located just above the cylindrical end pieces 20 of the pins 15 in the9Jlocked" position of the lock and is located between the opposed ends of the pieces 20 in the " locked" position of the lock.

Thus, the locking rod can be moved between a first position in which it permits inward movement of the pins 15 and a second position in which it prevents such inward movement.

The tubular member 1 is used in association with a retaining housing 25 as illustrated in Figures 5 and 6.

The housing 25 is manufactured from a high strength material such as hardened steel and includes a mounting plate 26 and a ring-shaped holder 27 which is connected to the plate 26 by a support 28. The plate 26, support 28 and holder 27 may either be formed as an integral unit, may be welded together or may otherwise be connected to define a relatively strong and rigid assembly. The plate 26 is formed with a series of apertures to receive screws for securely attaching the plate to a vertical face of a structural member of the vehicle chassis. Any other suitable way of securing the plate to such a structural member can be adopted. At least some of the screw receiving apertures are, in use, covered by a slide 30 which can be moved along a suitable track within the support 28 selectively to expose or cover the apertures and can be locked in place to prevent access to the securing screws.

Set in the internal surface of the ring shaped holder 27 is an annular groove 31.

The respective dimensions of the tube 1 and the holder 27 are such that the tube 1 can be inserted into the housing base first through the upper open end of the holder with a clearance therebetween. Because the rounded ends 23 of the pins 15 protude outwardly to positions proud of the internal diameter of the holder 27, they are moved inwardly against the action of the springs 25 as the tube 1 is moved progressively into and through the holder 27. Once the pins 15 are aligned with the annular groove 31, they are moved outwardly by the springs with the rounded ends 23 located within the groove 31.

On key operation of the lock 8, the rod 13 is moved downwardly to preclude inward movement of the pins 15 out of their location within the groove 31 thereby preventing removal of the tube from the holder. The rounded ends 23 of the pins 15 can move freely along the annular length of the groove 31 thereby inhibiting any attempt to cut through the hardened steel tube by means of a hacksaw or the like.

In use, the clamping plate 26 is secured firmly to a chassis member of the vehicle to be protected at a height above ground level at which1 when the tube 1 is positioned within the holder 27, its serrated end 4 either touches the ground, is closely adjacent to the ground or is sited at a position below ground level. For a vehicle such as a caravan, the selected chassis member is preferably within the caravan body so that all that is exposed to the outside is the downwardly protruding lower end of the tube 1. The holder 27 is preferably sited a distance of approximately three feet to one side or the other of the vehicle's axle. The clamping plate 26 is preferably attached to the selected chassis member by round-headed or hardened bolts which are themselves protected by antitheft mechanisms.

As and when required, the tube 1 is positioned within the holder 27 with the rounded ends of the spring-loaded locking pins 15 sited within the groove 31 of the holder.

The lock is then operated to move the locking rod 13 into the space between the cylindrical end pieces 20 of the pins 15 to prevent inward movement of the pins 15 and, subsequently, removal of the tube from the holder. For caravan use, the caravan is preferably raised onto its corner "steadies" before the tube 1 is located and locked in the housing. In this way, a tube length greater than the normal height of the housing above ground level can be accommodated.

Typically, operation of the anti-theft device is as follows. The trailer is positioned in the required location. The front of the trailer is lowered onto the trailer jockey wheel and the trailer rear is raised by operation of the rear stabilisers. The tube 1 is inserted into the holder 27 and locked in position. The trailer front end is then raised by the jockey wheel to achieve level standing and the front stabilisers lowered. The jockey wheel is removed and the trailer level adjusted by operation of the front or rear stabilisers. If the ground is uneven, wooden blocks or ramps may be used.

With the tube 1 locked in position, any attempt to tilt or move the vehicle is inhibited by the serrated tube end 4 making contact with the ground. The serrated end 4 is designed to co-operate with the ground in a sense further to inhibit vehicle movement.

To increase the effectiveness of the anti-theft device, the vehicle may firstly be positioned on ramps 32 as illustrated in Figures 7 and 8 each of which includes a suitably shaped aperture 33 through which the lower end of the tube 1 may protrude when the tube is positioned within the holder 27. In this arrangement, when sited within the holder 27, the tube length is such that without the ramps 32, the lower end of the tube 1 would extend below ground level. With this arrangement, where a trailer post hole is available, the ramps need not be used, the lower end of the tube 1 protruding into the trailer post hole.

It will be appreciated that the foregoing is merely exemplary of anti-theft devices in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the present invention. Thus, the tube 1 and holder 27 can be of a cross-section other than round and alternative locking mechanisms can be used provided that any such mechanisms effectively locks the tube 1 within the holder 27.

Claims (18)

1. An anti-theft device for vehicles which comprises a rigid housing for attachment to a structural member of the vehicle, the housing including an annular section into which can selectively be sited an elongate tubular member of a length approximating to or slighter greater than the distance between the housing when attached to the vehicle and the ground and means for locking the tubular member within the annular section of the housing.

2. A device as claimed in Claim 1 wherein the tubular member is closed at its upper end by a cap and at its lower end by a plug.

3. A device as claimed in Claim 2 wherein the plug has a serrated lower surface and carries on its upper face a cylindrical extension which fits firmly within the lower end of the tube.

4. A device as claimed in Claim 2 or Claim 3 wherein the cap includes a central opening to receive the cylindrical barrel of a key operated lock.

5. A device as claimed in any one of Claims 2 to 4 wherein outwardly extending handles are secured to the cap.

6. A device as claimed in any one of Claims 2 to 5 wherein the cap is secured to the tubular member by grub screws.

7. A device as claimed in any one of Claims 4 to 6 wherein the lock includes a backing plate which is screwed to the inner face of the cap and is so located by means of a spacer that the upper face of the barrel is positioned substantially flush with the outer face of the cap.

8. A device as claimed in any one of Claims 4 to 7 wherein the lock includes a locking rod which can be moved towards and away from the tubular member by a key inserted into the end face of the lock sited flush with the cap surface.

9. A device as claimed in any one of Claims 4 to 8 wherein a carrier for one or more ball ended spring loaded pins is secured to the inner circumference of the tubular member at a position just below the lock.

10. A device as claimed in Claim 9 wherein the carrier comprises an annular base formed with shaped recesses to receive the ends of grub screws which pass through apertures formed in the tubular member to lock the carrier in place.

11. A device as claimed in Claim 9 or Claim 10 wherein the carrier is formed in two parts which can be drawn together by screws passing through bores to trap and retain the ball ended pins therebetween.

12. A device as claimed in Claim 11 wherein the pins each have a rounded end and include cylindrical end pieces which protrude into and through apertures and carry collars between their rounded ends and the cylindrical end pieces.

13. A device as claimed in Claim 12 wherein the rounded ends of the pins protrude through suitably positioned apertures formed in the tubular member and the collars are urged into contact with the tubular member interior by compression springs.

14. A device as claimed in any one of Claims 1 to 13 wherein the housing includes a mounting plate and a ring shaped holder which is connected to the plate by a support.

15. A device as claimed in Claim 14 wherein the plate, the support, and the holder are formed as an integral unit.

16. A device as claimed in Claim 14 or Claim 15-wherein the plate is formed with a series of apertures to receive screws for attaching the plate to a vertical face of a structural member of the vehicle chassis.

17. A device as claimed in Claim 16 where at least some of the screw receiving apertures are, in use, covered by a slide which can be moved along a suitable track within the support selectively to expose or cover the apertures.

18. An anti-theft device for vehicles substantially as herein described and illustrated in Figures 1 to 8 of the accompanying drawings.