Anti-theft device
Page 65
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From a special nut designed to beat the battery thief has stemmed a whole range of anti-theft devices. They are introduced by Ellis (Colchester) Ltd. and the nut makes every unit a simple and easy-to-fit thief deterrent.
The principle of the nut (or bolt head) is that it has a predetermined shape which mates only with a registered key. Any firm using the device can specify the number of styles of key to be used in its fleet.
Surrounding the nut is a freely rotating sleeve which serves two purposes. The first is to effectively prevent the nut being slackened by a universal tool such as a pipe-grip, Stilson or chainwrench. The second is to provide adequate wall strength for the key which is designed to be a close fit within the sleeve. Thus the key can be made with a thin wall ensuring that no tool heavy enough to apply sufficient torque to undo the nut can be used. Because of the number of variations possible in the design of the keys—they run into thousands—simple duplication is unlikely.
Two of the obvious applications for the nut are on battery carriers and on road or spare wheels, The number of these particular items stolen each year is frightening and the application of only one anti-theft nut to each wheel (or pair of wheels, on a big artic, for instance) provides adequate protection for up to £600 worth of equipment.
The use of the shrouded nut (bolt) principle has made the fitting of a unique device by Ellis a few minutes job. This unit comprises a clamp which is attached to the steering column and carries a cross-bar pivoted at its centre. Within the pivot is a spring-loaded ratchet which allows the cross-bar to rotate in one direction only. The ratchet is released by a Yale-type barrel
lock key which is supplied on a registration basis.
In operation when a driver leaves his vehicle he simply puts his foot on the swivelling cross-bar and presses it down onto the brake pedal. At the same time the opposite arm of the cross-bar comes up beneath the clutch pedal rendering this inoperable. As the ratchet takes account of brake adjustment the vehicle is locked on all wheels as well as being clutchless.
This unit—and all the others in the range—is hardened and so designed that it is virtually impervious to attack by hacksaw or other cutting tools, excluding of course, acetylene burners.
Yet another application of the device is that of a king-pin lock. Like others of its type, this fits around the kingpin, effectively preventing a tractive unit from being coupled to the trailer. The lock is secured by a sleeved bolt which can only be undone with the appropriate key. It is once again designed to be attackproof.
Made by: Ellis (Colchester) Ltd., Mars OSA Division, 89/90 Turnmill Street, London, EC1.