GB2295996A

GB2295996A - Security device for the steering column of a vehicle

Info

Publication number: GB2295996A
Application number: GB9425505A
Authority: GB
Inventors: Ivan John Knight
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-12-17
Filing date: 1994-12-17
Publication date: 1996-06-19
Also published as: GB9425505D0

Abstract

An anti-theft security device with particular application to the steering column of a vehicle includes a first shaft 2 rotatable with a handwheel and a second shaft 1 axially in line with the first shaft. Coupling means 3 are provided which in a first position couple the two shafts together, and in a second position do not couple the shafts together. When the device is used in a vehicle, the two shafts make up the steering column of the vehicle and when they are not coupled together, the vehicle is undrivable. Means are provided for locking the coupling means in the first or second position. <IMAGE>

Description

TITLE Security device, particularly for the steering column of a vehicle DESCRIPTION: Technical Field The invention relates to a security device for a shaft, with particular relevance to the steering column of a vehicle.

Background Car theft is becoming an increasingly serious problem, and numerous different security devices for vehicles have been proposed.

Electronic immobilising devices, together with audible alarms, are very common. However, they are expensive, prone to f; ts, and do not deter the more sophisticated car thief. As audible alarms become more popular, they are more universally ignored.

Simple mechanical devices for preventing movement of the steering wheel, gear lever or accelerator are enjoying increasing popularity. Some of these have been found to be reliable, but with sufficient force many can be removed. It can also be inconvenient having to put on the device each time the vehicle is left.

Steering locks are provided in most vehicles, whereby the steering column may be locked into one position until an ignition key is inserted. However it is possible to break such a steering lock if sufficient force is used, thereby rendering the vehicle drivable. The use of the steering lock simply tends to increase the damage done to the stolen car by the thieves.

There is therefore a need for a reliable device to prevent car theft, which cannot be overcome by the use of force.

Summary of the Invention The invention provides security apparatus comprising: a first shaft; a handwheel for rotating the first shaft about its axis; a second shaft axially in line with the first shaft; coupling means movable between a first position in which the coupling means prevents relative rotation of the first and second shafts and a second position in which the coupling means does not prevent relative rotation of the first and second shafts; and means for locking the coupling means into the first position or the second position.

Where the security arrangement is used as an immobilising device for a vehicle, the first and second shafts make up the steering column of the vehicle, and the handwheel is the steering wheel of the vehicle. In this case locking the coupling means into its second position renders the vehicle undrivable, because movement of the steering wheel has no effect on the position of the vehicle wheels.

However the invention is not limited to use on a vehicle, and may be used on any manually turned shaft, of any size. It may be used in many engineering applications, for instance to prevent the unauthorised opening or closing of lockable valves in pipelines for oil or chemicals. In some applications, the handwheel may be replaced by a lever or any other means for manual rotation of a shaft.

Preferably, the coupling means includes a sleeve which surrounds and engages the first and/or second shafts. The coupling means may be movable axially between a first position in which it surrounds and engages both the first and second shafts, thereby preventing relative movement therebetween, and a second position in which it engages only one of the shafts, and allows such relative movement. The engagement between the shafts and the coupling may be provided by splines on the shafts and complementary recesses in the interior of the coupling sleeve.

However, any means for coupling and uncoupling the two shafts may be used. For example a toothed "gear" could be arranged at the side of the shafts such that it is movable between a first position in which it engages both shafts and a second position in which it engages just one shaft.

Preferably the means for locking the coupling means into the first position or the second position is a double acting deadlock. Such a lock makes it impossible for the coupling to move between the two positions without the use of the correct key. Additional safety features may be included, particularly in the vehicle steering column embodiment, to ensure that the two shafts cannot be disengaged at an inappropriate time.

Brief Description of the Drawings Figure 1A is a cross-section through a security device in accordance with the invention, used on the shaft of a steering wheel shown in a first (driving) position; Figure 1B is the device of Figure 1, shown in a second (non-driving) position; Figure 2 is an enlarged view of the end of the steering wheel shaft of Figure 1 showing the way in which it engages the steering driven shaft Figure 3 is an end view of the shaft of Figure 2; Figure 4 is an enlarged view of the end of the steering driven shaft of Figure 1, showing the way in which it engages the steering wheel shaft of Figure 2; Figure 5 is an end view of the shaft of Figure 4; Figure 6 is an end view of the lock plate of Figure 1; Figure 7 is a side view of the coupling of Figure 1; and Figure 8 is an end view of the coupling of Figure 7.

Description of the Preferred Embodiment Referring to Figures 1 and 2, a steering wheel shaft 2 includes an outer end 10 for affixing to the steering wheel of a vehicle. A steering driven shaft 1, which has an axis in line with that of the steering wheel shaft, controls the steering mechanism and therefore the position of the front wheels of the vehicle. A cylindrical spigot 7 on the steering driven shaft 1, shown clearly in Figure 4, slots into a complementary bore 8 in the steering wheel shaft 2 (shown clearly in Figure 2) and ensures that the two shafts remain in line with one another. However this engagement does not prevent relative rotation of the two shafts.

The inner end of each shaft includes a splined area, shown clearly in Figures 2, 3, 4 and 5. The splines allow a coupling 3, which has complementary internal recesses (Figure 8) to surround and engage the inner ends of the shafts such that no relative rotation can occur between the shafts and the coupling.

Figure 1A shows the coupling 3 in a first position in which it surrounds and engages the inner ends of both the steering driven shaft 1 and the steering wheel shaft 2.

When the coupling is in this position, no relative rotational movement can occur between the two shafts, and they behave as if they were a single shaft. Rotation of the steering wheel causes rotation of both shafts and therefore of the front wheels of the vehicle. Figure 1B shows the coupling 3 in a second position in which it surrounds and engages only the steering wheel shaft 2. In this position, relative rotation of the two shafts is not prevented and turning the steering wheel shaft does not result in any movement of the steering driven shaft or of the wheels of the vehicle.

Movement of the coupling 3 between these first and second positions is effected by a lock 4 having a lock plate 5.

As shown in Figure 7, the coupling 3 includes a waisted portion 6 of narrow diameter. The lock plate 5, whose shape is shown in Figure 6, fits securely into this waisted portion, and movement of the lock plate between the position shown in Figure 1A and that shown in Figure 1B results in axial movement of the coupling between its two different positions. Although no relative axial movement of the lock plate and the coupling is possible, relative rotation may occur to allow rotation of the shaft(s).

The lock is a double acting deadlock, and the lock plate can only be moved from one position to another by the use of the correct key, inserted through keyhole 12 in cover 11.

When a driver leaves a vehicle, the coupling may be left in its second position in which it surrounds and engages the steering wheel shaft 2 only. If a thief breaks into, and tries to drive the car, he finds that moving the steering wheel has no effect on the position of the wheels, and the car is effectively undrivable.

Claims

1. A security apparatus comprising: a first shaft; a handwheel for rotating the first shaft about its axis; a second shaft axially in line with the first shaft; coupling means movable between a first position in which the coupling means prevents relative rotation of the first and second shafts and a second position in which the coupling means does not prevent relative rotation and of the first and second shafts; and means for locking the coupling means into the first position or the second position.

2. A security apparatus according to claim 1 wherein the first and second shafts make up the steering column of a vehicle.

3. A security apparatus according to claim 1 or claim 2 wherein the means for locking the coupling means into the first position or the second position includes a double acting deadlock.

4. A security apparatus according to any preceding claim wherein a central spigot on either the first shaft or the second shaft engages a complementary bore in the other shaft.

5. A security apparatus according to any preceding claim wherein the means for locking the coupling means into the first position or the second position includes a portion for engaging an annular groove in the coupling means.

6. A security apparatus according to any preceding claim wherein the coupling means includes a sleeve which in its first position surrounds and engages the first shaft and the second shaft, and in its second position surrounds and engages either only the first shaft or only the second shaft.

7. A security apparatus according to claim 6 wherein the engagement between the shafts and the coupling means is provided by splines on the shafts and complementary recesses on the interior of the coupling means.

8. A security apparatus substantially as described herein with reference to the drawings.