This invention relates to a security device, and more particularly to an anti-theft device for a caravan, trailer or the like, to prevent it from being stolen by securing it to the ground.

Conventional methods of securing caravans, trailers and the like include wheelclamps and hitchlocks. These provide varying degrees of security, depending on how robustly they are constructed. An object of this invention is to provide an improved security device which will act as a substantial and visible deterrent to a thief.

The invention provides an anti-theft device for a caravan, trailer or the like which incorporates a towing hitch having jaw means for gripping the ball of a tow bar and an operating handle accessible from above for opening and closing said jaw means, the anti-theft device comprising an upstanding post adapted to be anchored directly or indirectly to the ground, an upper end of said post comprising a fixed ball for engagement with the jaw means of the towing hitch; a cover member which is detachably engageable with the upper end of the post such that, when in engagement, the cover member substantially covers the towing hitch and the fixed ball engaged with the jaw means; and locking means for detachably locking the cover member so as to prevent disengagement from the post, the cover member thereby preventing access to the operating handle.

The post is preferably in lockable engagement with a socket which is permanently anchored in the ground.

The cover member preferably has side walls with inward-facing flanges at the lower ends, said flanges being adapted to slidingly engage with a pair of opposed slots near the upper end of the post.

The locking means preferably includes a bolt adapted to engage with a pair of holes in register with each other in the respective side walls, and in relationship to the operating handle such that abutment between the bolt and the operating handle prevents sliding withdrawal of the cover member.

Reference is now made to the accompanying drawing, which is an exploded perspective view of the components of a security device according to a preferred embodiment of the invention, together with a towing hitch of conventional design.

The security device according to the invention is adapted to be used with a caravan, trailer or the like having conventional towing components. A caravan or trailer draw bar 1 (shown partially) is fixed to a towing hirch 2 by means of a towing head fixing bolt 3. The towing hitch 2 is shaped as a substantially semi- cylindrical shroud with a rounded front end, the interior being accessible from its underside. A pair of jaw members (not shown) is accommodated at the front of the towing hitch. One jaw member is fixed and the other is movable. The movable jaw member is pivoted to an inverted L-shaped operating handle 4 which emerges from a longitudinal slot in the top of the towing hitch. Raising of the operating handle 4 will thus cause the jaws to open, and vice versa. During normal towing of the caravan or trailer, the jaws engage with a ball incorporated in the tow bar of a towing vehicle.

A tubular steel socket 5 taking the form of a hollow cylinder is permanently anchored in the ground, for example, by concreting into a hole. To assist in securing the socket, two opposing transverse lugs 6 are secured to the socket approximately half way along its length. The lugs 6 also project into the internal bore of the socket 5 for engagement with an upstanding post 7 as described below.

The substantially cylindrical post 7, which is preferably of solid steel, is inserted into the socket 5. The post has a bar welded to its base and projecting from opposite sides to form a pair of opposed lugs 8. The post has a welded-on handle 9 to assist manipulation. When the post is inserted into the socket it is rotated on its axis so that the lugs 8 do not strike the lugs 6 in the socket. Thereafter, the post 7 is rotated through 90°, and is thereby prevented from being lifted more than approximately half way out of the socket because of engagement between the lugs 8 with the underside of the lugs 6 in the socket.

The top of the steel post 7 is machined to form an integral ball 10, having similar dimensions to the ball of a conventional tow bar. This ball can thus be engaged by the jaws in the towing hitch. To assist in this engagement, the post 7 can be vertically adjusted in the socket 5 and there is also a limited degree of horizontal movement of the post resulting from looseness of fit in the socket.

Just below the ball 10 at the top of the steel post are two parallel, horizontal slots 11 on opposite sides. The slots 11 serve for sliding engagement of a cover member 12, which is a steel box of substantially

rectangular section. The cover member 12 has vertical side walls 13 which terminate at their lower end in inward-facing flanges 14 separated by a longitudinal channel 15. The flanges 14 are dimensioned for sliding engagement with the respective slots 11 in the post, the reduced thickness of the post between the slots 11 being accommodated in the channel 15. The cover 12 has an end plate 16 which defines an opening dimensioned to slide over the towing hitch 2, including the operating handle 4. The cover 12 has a completely closed end plate (not shown) at the opposite end to the end plate 16.

With the ball 10 engaged in the jaws of the towing hitch 2, the cover 12 can thus slide on along the slots 11 in the post, to such an extent that the towing hitch, including the operating handle, is completely covered. In this position, there is no access to the operating handle, so the jaws cannot be opened to release the ball 10. Furthermore, because of the engagement between the flanges 14 of the cover with the slots 11, the post 7 cannot be turned around its longitudinal axis so as to disengage the lugs 8 from the lugs 6 in the socket.

In order to lock the cover 12 in this position, and prevent its sliding withdrawal, a pair of holes 17, 18 is provided in register in the two side walls. A steel bolt 19 is inserted through the hole 17 and extends internally across the width of the cover so that its tip projects through the hole 18. The holes 17, 18 are positioned such that the bolt 19 passes under the upper limb of the operating handle 4, and close to the edge of the operating handle facing towards the draw bar 1. Consequently, abutment between the bolt 19 and the operating handle 4 prevents sliding withdrawal of the

cover 12 .

The head 20 of the bolt is sufficiently wide not to pass through the hole 17, and is protected by a circular steel flange (not shown) on the outer side of the cover surrounding the hole 17. The tip 21 of the bolt, which projects through the hole 18, incorporates a hole through which the hasp of a padlock 22 or similar locking device can be placed. When in the locked position, the padlock 22 is protected by a steel shroud 23 projecting outwardly from the side face 13 of the cover, and shielding the front of the padlock. The padlock 23 is preferably of the type having a removable hasp, to facilitate placement and locking behind the shroud 23.

In the locked position described above, the cover cannot be removed from the towing hitch because it is secured by the bolt which is padlocked in place. The towing hitch cannot be released from the post 7 because the operating handle 4 cannot be moved to release the jaws. The post 7 cannot be lifted out of the ground because it cannot be rotated to release the locking lugs in the socket, as a result of the cover being engaged with the slots 11 of the post.

If an unauthorised attempt is made to release the security device by sawing through the steel post, the cover and steel ball will still be secured to the towing hitch, preventing the caravan or trailer from being towed away in the conventional manner.

A U-shaped staple 26 is additionally provided to strengthen the device. The staple is shaped to provide two flat vertical limbs joined by a flat

horizontal part. Each of the vertical limbs has a hole

27 near its top, the two holes 27 being in registration with each other. Two slots 28 are provided in the cover member 12, one in each of the flanges 14. These slots

28 are positioned and dimensioned so as to receive the respective vertical limbs of the staple 26. During locking of the device, before the bolt 19 is inserted, the staple 26 is inserted through the slots 28 from below. When the staple is fully inserted, the intermediate flat portion of the staple rests against the underside of the flanges 14, and the holes 27 in the staple are then in registration with the holes 17,18 in the cover. When the bolt 19 is inserted, it thus passes through the holes 17,27 and 18 in both the cover and the staple, and thus locks the staple to the cover. In the resulting locked position, the staple adds strength to the cover in that it hinders any attempt to lever the sides of the cover apart by inserting an implement between the flanges 14.

When the caravan or trailer is taken away from its normal parking place, where the socket is anchored in the ground, the cover can still be used on its own as a conventional towing hitch cover.

In this respect, an adapter plate 30 is provided to minimise lateral movement of the cover 12. The adapter plate 30 is a substantially rectangular plate having underhanging flanges along two opposite sides and a cut away portion at one end. Near the opposite end of its upper surface, a ring 31 is affixed. The ring 31 is of similar dimensions to the ball 10. On the underside of the adapter plate, except for the cut away portion, two longitudinal web portions 32 are affixed, and these terminate in respective outwardly extending flanges 33.

During use of the device as a conventional hitch cover, the jaws in the hitch 2 are used to grip the ring 31 of the adapter plate, which is thereby secured to the hitch. In this position, the gap between the upper sides of the flanges 33 and the lower end of the side flanges of the adapter plate 30 defines channels for receiving the flanges 14 of the cover 12, in sliding relationship similar to that which occurs when the flanges 14 cooperate with the slots 11 in the post 7. The cover 12 is thus secured in position shrouding the hitch, and it can be locked in such position using the staple 26, locking bolt 19 and padlock 22 in the same manner as described above.

When the caravan or trailer is taken away from its normal parking place, the post 7 is generally removed from the ground socket 5, and the socket is then sealed at its open upper end by means of a cover plate 34.