GB2327696A

GB2327696A - A Tyre Deflation Device

Info

Publication number: GB2327696A
Application number: GB9712693A
Authority: GB
Inventors: Hugh Marsh; Paul Marsh
Original assignee: NORTHERN SERVICES Ltd
Current assignee: NORTHERN SERVICES Ltd
Priority date: 1997-06-18
Filing date: 1997-06-18
Publication date: 1999-02-03
Also published as: GB2327696A8; GB9712693D0

Abstract

A tyre deflation device (10) comprises a cover (11), a plurality of deflators (26), a resilient biasing means (27), and a lock (28). The tyre deflation device (10) has a first mode of operation in which the cover (11) covers the deflators (26) and is locked in place by the lock (28) so that a tyre of a vehicle may be driven over the cover (11) with no resulting damage. In a second mode of operation, actuated by the lock (28), the cover (11) covers the deflators (26) when a load less than a predetermined limit is applied to the cover (11). This limit is determined by the action of the resilient biasing means (27) on the cover. When a load greater than the predetermined limit is applied to the cover (11) by the tyre of a vehicle, the cover (11) is depressed thus exposing the deflators (26) which act to puncture and deflate that tyre.

Description

Tyre Deflation Device The present invention relates to a security device to control the unauthorised movement of vehicles. In particular it relates to a device which has a first state in which a tyred vehicle may drive over the device and a second state in which any tyred vehicle driving over the device has its tyres damaged so that the vehicle can not be driven further. Using this device the unauthorised movement of a tyred vehicle may be controlled by providing an authorised person with the ability to change the state of the device while preventing an unauthorised person from changing the state of the device.

There are a number of situations in which it is useful to be able to control the movement of vehicles: e.g. the stealing of parked vehicles; stopping moving stolen vehicles; and preventing vehicles being driving away before the occupants have paid for goods, e.g. at a petrol station. However, it is often impractical to provide a sufficiently robust physical barrier for domestic use, owing to the cost and substantial construction work involved. Further, sufficiently robust physical barriers are often unwieldy and can cause delays in situations where a frequent flow of traffic is necessary, such as a petrol station forecourt or parking garage. Furthermore, there are few methods which provide a way of halting a speeding vehicle, which needs to be stopped for security or safety reasons, without harming the passengers, such as at security check points and the like, or in the case of joy riders. Hence there is a need for a device which can safely control the movement of tyred vehicles, which is sufficiently robust to stop moving vehicles, which can prevent the driving away of stationary vehicles without significantly damaging the vehicles, and which also does not hinder the authorised use of vehicles.

According to a first aspect of the invention, there is provided a vehicle tyre deflation device, for selectively allowing vehicles to drive over it unimpeded, comprising a ramp having: a cover section; a deflator, in which the cover section and deflator are relatively movable between a first configuration in which the deflator is covered by the cover section and a second configuration in which the deflator is exposed by the cover section; and biasing means which act on the cover section to maintain the cover section and deflator in the first configuration when a vehicle applying a load less than a predetermined load drives across the cover section and allows the cover section and deflator adopt the second configuration when a vehicle applying a load greater than the predetermined load drives across the cover section, thereby exposing the deflator to at least one vehicle tyre so as to puncture the vehicle tyre.

Preferably the cover section forms part of a tyre engaging surface of the ramp.

According to a second aspect of the invention, there is provided a tyre deflation device comprising: a cover; a deflator; a resilient biasing means; and a lock, in which the tyre deflation device has a first mode of operation in which the cover covers the deflator and is locked in place by the lock so that a tyre of a vehicle may be driven over the cover and a second mode of operation, actuated by the lock, in which the cover covers the deflator when a load less than a predetermined limit, determined by the action of the resilient biasing means on the cover, is applied to the cover and the cover moves to expose the deflator when a load greater than a predetermined limit is applied to the cover by the tyre of a vehicle driven over the cover so that the deflator can puncture the tyre of the vehicle driven over the cover.

A device according to the second aspect has several advantages.

It is very safe as the predetermined limit can be set so that the device will not cause injury to innocent pedestrians. As the device can be driven over, in its first mode of operation, it does not unduly hinder the normal flow of traffic. Also, the device can be rapidly actuated, as it does not have the inertia associated with massive physical barriers.

The lock may be inaccessible. The lock may be remotely operated. In this way, the device can not be locked and unlocked by anyone other than an authorised person. The lock may be operable by any suitable mechanism, such as a suitably coupled motor, hydraulically, pneumatically, electromechanically, or electromagnetically. The lock may be a simple mechanical device which can only be accessed by the use of a security device, e.g. a key, to prevent unauthorised operation of the lock. By providing an inaccessible lock only authorised people can lock and unlock the device thereby controlling the possibility of moving any vehicle which would have to drive over the device in order to be relocated. The lock may be remotely operated by control wires or wirelessly, e.g. by transmitting radio signals.

Preferably, the device has a limiter which limits the position of the cover under the action of the resilient biasing means on the cover. The limiter may be permanently fixed in position by brazing, welding or the use of adhesives. The predetermined limit may be set by altering the position of the limiter. In this case the position of the limiter may be variable so that the predetermined limit may be chosen to that appropriate for the use of the device. The limiter may be provided having a screw thread so that its position can be altered or may be associated with any other mechanism which allows its position to be altered and then fixed.

Preferably, the device has a hinged cover so that the device can alter its shape from a ramp profile, when a load less than the predetermined limit is applied to the cover, to a substantially flat profile, when a load greater than the predetermined limit is applied to the cover. By providing the device with a ramp profile, the device can be used in situations where it is desirable not to hinder the flow of traffic. Further, the ramp profile can be chosen so that the device acts as a speed bump or "sleeping policeman", providing the further feature of a road safety device.

Preferably, the lock has a rigid member which abuts the cover when the device is in the first mode of operation so as to lock the cover in place, and the rigid member can be moved out of abuttal with the cover when the lock is disengaged so that the device is in the second mode of operation. The rigid member serves to mechanically transmit the load from the cover to prevent the deflator being exposed. As it is the rigidity of the member which provides the support, massive loads may safely drive over the device owing to the very great forces that are required to cause the bulk deformation of the material of the rigid member.

The deflator may comprise spikes. Providing a number of suitably spaced spikes ensures that there are no gaps between the spikes sufficiently wide to allow tyres to drive over the device without being punctured. The spikes may be hollow and adapted to remove a plug of material from a vehicle tyre when a vehicle tyre is punctured by them. Some modern tyres are adapted to be self-repairing when punctured. Hence, the spikes may be adapted to remove a plug of material from the tyre sufficiently large to prevent the tyre self-repairing so as to disable the vehicle.

Preferably the device has a base and the base comprises a flanged channel. The base channel may serve the further purpose of acting as a drainage conduit, thereby preventing flooding which may occur due to the ramp profile of the device acting as a barrier to the egress of liquids. The flanged channel may bear the deflator and the resilient biasing means.

The channel may also serve to securely locate the device in the ground.

The cover may have an aperture via which the deflator is exposed when the device is in the second mode of operation and a load greater than a predetermined load is applied to the cover.

According to a third aspect of the invention there is provided a vehicle tyre deflation device which is intended to be positioned in the path of travel of a vehicle having inflated tyres and the device being actuable between a safe operating mode in which unimpeded vehicle passage over the device is permitted and an arresting mode in which vehicle passage is impeded, and in which the device comprises: a cover which can be driven over by at least one tyre of the vehicle; a deflator co-operable with the cover, the deflator and the cover being relatively movable between an inoperative configuration of the deflator and an operative tyre deflating configuration when the device is in its arresting mode; actuating means operative to convert the device from the safe operating mode to the arresting mode; and biasing means for maintaining the deflator in its inoperative configuration, when the device is in its arresting mode, for loads applied to the cover less than a predetermined load, in which the biasing means is capable of being overcome by a load in excess of the predetermined load in order to allow relative movement of the deflator to its tyre deflating configuration.

A device according to the third aspect of the invention therefore can be positioned on or in a road so as to permit authorised vehicle traffic to drive over it but which can be "armed" by any suitable operation of the activation means, so as to impede unauthorised travel over the device.

In the armed state of the device, a vehicle tyre will inevitably come into contact with the deflator, which causes rapid deflation of the tyre and thereby render the vehicle undrivable. However, application of loads to the cover less than the predetermined load will not overcome the biasing means and safe passage over the device will be permitted, e.g. to pedestrians, when the device is armed to its arresting mode.

Preferably the cover is incorporated into any suitable part of a tyre engaging surface, e.g. into a ramp, in which case conveniently the cover forms a crown portion of the ramp.

A preferred embodiment of a tyre deflation device will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a cut away perspective view of a tyre deflation device; Figure 2 shows a plan view of the device; Figure 3 shows a plan view of the base of the device; Figures 4a and 4b show end views of the device in its two different operating states; and Figures 5a and 5b show partial longitudinal sections of the device in its two different operating states; Identical items in the different Figures share common reference numerals.

With reference to Figures 1 to 3, there is shown a tyre deflation device generally designated by reference numeral 10.

The device comprises a cover 11 having three parts, a first ramp part 12 a central part 13 and a second ramp part 14. The central part is in the form of a rectangular box section. The first and second ramp parts bear formations to increase their grip and are each joined to a respective top vertex of the central part by hinges 15 and 16. A number of apertures 17 are provided in the top face 18 of the central part. A similar number of apertures are provided in the bottom face 19 of the central part and aligned with the apertures in the top face, providing pairs of aligned apertures. Alternate pairs of apertures are connected by a reinforcing guide cylinder 20.

The device also has a base 21. The base comprises an open rectangular channel 22 with a pair of flanges 23, 24 each connected to a respective top vertex of the channel to form an inverted 'top hat' structure. The bottom face 25 of the base channel bears a deflator in the form of four spikes 26. Each spike is hollow and adapted to remove a plug of material from items impaled upon them. The bottom face of the base channel also bears resilient biasing means in the form of four springs 27 each of which encircles a respective one of the four spikes 26. A lock 28 is provided in the base. The lock 28 is in the form of an axle 29 passing through pivoting formations 30 which allow the axle to be rotated. Five rigid members, in the form of arms 31, extend from the axle perpendicularly to its length.

A mechanism is provided (not shown) which can rotate the axle between a first position in which the rigid arms are upright and perpendicular to the bottom face of the base channel, and a second position in which the rigid arms are horizontal and parallel to the bottom face of the base channel.

Alternate spikes each have a respective limiter 32 secured to them. The springs 27 are compressed between the bottom face of the base channel 25 and the underside of the bottom face 19 of the central part of the cover. As such the springs act to urge the cover away form the base. However, the limiters act on the top side of the bottom face 19 of the central part of the cover 13 to prevent the cover 11 from being separated from the base 21 by the action of the springs 27. In this way the springs are maintained in a compressed, loaded state. The degree of compression of the springs is determined by the location of the limiters on the spikes. The predetermined limit is set by the combined effect of the strength of the springs used and the position of the limiters on the spikes.

The operation of the device will now be described with reference to Figures 4a, 4b, 5a & 5b. The device has two modes of operation and is switched between the two by actuating the lock 28.

In the first mode of operation the device is locked so that the cover does not move downwards towards the base irrespective of the load applied to the cover. The lock is rotated into the first position so that the rigid arms 31 are vertical, as shown by ghost lines in Figs 4a & 5a, causing the underside of the bottom face 19 of the central cover part to be engaged by the free ends of the rigid arms. Now any load applied to the cover is borne by the rigid arms and transmitted into the base so that the cover does not move downwards towards the base.

Hence, in this first mode of operation, any vehicle can drive over the tyre deflation device without having its tyres damaged as the lock mechanically prevents the cover moving to expose the spikes, irrespective of the load on the cover. The first 12 and second 13 ramp sections of the cover aid the passage of a vehicle over the tyre deflation device giving it a ramp profile and so the tyre deflator does not significantly impede the flow of traffic and acts similarly to a speed bump or "sleeping policeman".

The second mode of operation of the tyre deflation device is actuated by moving the lock into its second position. The lock may be moved by any suitable mechanism such as by the action of a suitably coupled motor, hydraulically, pneumatically, electromechanically, or electromagnetically. The lock is capable of being controlled remotely, such as by wire or wirelessly, so that the lock is inaccessible and can only be controlled by an authorised person. In its second position, the rigid arms no longer support the cover and rather the cover is supported by the action of the springs. The strength of the springs and the position of the limiters is chosen so that a predetermined load must be applied to the cover before it moves downwards into the base and exposes the spikes.

If a person, animal or vehicle of less than a predetermined weight steps on, or drives over, the cover of the device, then as the load applied to the cover is less than the supporting force provided by the action of the springs on the cover, the cover will not move so as to expose the spikes and so the person, animal or vehicle can proceed without being injured or damaged. However, when a vehicle, which is sufficiently massive that it can apply a load to the cover greater than the predetermined load, attempts to drive over the cover, the springs can no longer support the cover and so the cover moves downwards into the base, as shown in Figures 4b and 5b, exposing the spikes which can then puncture the tyres of the vehicle. As can be seen in Figures 4a and 4b the profile of the tyre deflation device changes from that of a ramp to substantially flat.

As will be appreciated there are a great number of potential uses for such tyre deflation devices. They would be of particular use at service stations to prevent customers driving away without paying for their petrol. The cashier would merely need to press a button to put the device into its second mode of operation so that it would puncture the tyres of the offenders vehicle as it tries to escape. As the tyre deflator device has the ramp profile of a speed bump, it will not hinder the flow of traffic. Further, the tyre deflator device can be rapidly actuated as it does not rely upon a large physical barrier to stop vehicles and so does not have the inertia of such physical barriers. Furthermore, by providing a line of individual tyre deflator device units across the entrance/exit it is possible to selectively activate the units. A line of individual units also has the safety feature of only exposing the spikes locally, i.e. under the offending vehicle tyres and not across the width of the line of units, thereby preventing injury to any innocent parties walking over the devices.

The base channels of a line of tyre deflator device units may also double as a drainage conduit, such as are often provided at the entrance/exits to service station forecourts, and allow liquids to drain away that may otherwise be trapped by the ramp profile of the units.

Tyre deflator devices may also be used at the exit to commercial and domestic garages and drives thereby preventing the unauthorised driving away of vehicles, by being left in the second mode of operation and requiring the authorised user of the vehicle to lock the tyre deflator in its first mode of operation before driving away. Again the requirement that a load greater than a predetermined load be applied to the cover before the spikes are exposed acts as a safety feature of the device preventing the accidental injury of people and animals.

Various modifications to the embodiment described are envisaged. In particular, a modified tyre deflator device with a flat base is envisaged which would be particularly suitable for safely stopping cars driven by joy-riders or as portable, temporary security devices. Further, a modified tyre deflation device which does not have a lock is also envisaged so that the device is always in the second mode of operation. Such a device would be for use in situations where it is necessary to prevent vehicles entering or leaving certain areas, e.g.

pedestrian zones or cycle paths.

Claims

CLAIMS:

1. A Vehicle tyre deflation device, for selectively allowing vehicles to drive over it unimpeded, comprising a ramp having: a cover section; a deflator, in which the cover section and deflator are relatively movable between a first configuration in which the cover covers the deflator and a second configuration in which the cover exposes the deflator; and biasing means which act on the cover section to maintain the cover section and deflator in the first configuration when a vehicle applying a load less than a predetermined load drives across the cover section and allows the cover section and deflator to adopt the second configuration when a vehicle applying a load greater than the predetermined load drives across the cover section, thereby exposing the deflator to at least one vehicle tyre so as to puncture the vehicle tyre.

2. A device as claimed in claim 1, in which then cover section forms part of a tyre engaging surface of the ramp.

3. A tyre deflation device for controlling the unauthorised movement of tyred vehicles comprising: a cover; a deflator; a resilient biasing means; and a lock, in which the tyre deflation device has a first mode of operation in which the cover covers the deflator and is locked in place by the lock so that a tyre of a vehicle may be driven over the cover and a second mode of operation, actuated by the lock, in which the cover covers the deflator when a load less than a predetermined limit, determined by the action of the resilient biasing means on the cover, is applied to the cover and the cover moves to expose the deflator when a load greater than the predetermined limit is applied to the cover by the tyre of a vehicle driven over the cover so that the deflator can puncture a tyre of a vehicle driven over the cover.

4. A device as claimed in claim 3 and having a limiter which limits the position of the cover under the action of the resilient biasing means on the cover.

5. A device as claimed in claim 3 or claim 4 and having a hinged cover so that the device can alter its shape from a ramp profile, when a load less than a predetermined limit is applied to the cover, to a substantially flat profile, when a load greater than a predetermined load is applied to the cover.

6. A device as claimed in any of claims 3-5, in which the lock has a rigid member which abuts the cover when the device is in the first mode of operation so as to lock the cover in place, and the rigid member can be moved out of abuttal with the cover when the lock is disengaged so that the device is in the second mode of operation.

7. A device as claimed in any of the preceding claims, in which the deflator comprises spikes.

8. A device as claimed in claim 7, in which the spikes are hollow and adapted to remove a plug of material from a vehicle tyre when a vehicle tyre is punctured by them.

9. A device as claimed in any preceding claim and having a base, in which the base comprises a flanged channel.

10. A device as claimed in claim 9, in which the flanged channel bears the deflator and the resilient biasing means.

11. A device as claimed in any of claims 3-10, in which the cover has an aperture via which the deflator is exposed when the device is in the second mode of operation and a load greater than a predetermined load is applied to the cover.

12. A device as claimed in claim 4, in which the predetermined load can be set by altering the position of the limiter

13. A device as claimed in any of claims 3-12, in which the lock is remotely operable.

14. A vehicle tyre deflation device which is intended to be positioned in the path of travel of a vehicle having inflated tyres and the device being actuable between a safe operating mode, in which unimpeded vehicle passage across the device is permitted, and an arresting mode, in which vehicle passage is impeded, and in which the device comprises: a cover which can be driven over by at least one tyre of the vehicle; a deflator co-operable with the cover, the deflator and the cover being relatively movable between an inoperative configuration and an operative tyre deflating configuration when the device is in its arresting mode; actuating means operative to convert the device from the safe operating mode to the arresting mode; and biasing means for maintaining the deflator in its inoperative configuration, when the device is in its arresting mode, for applied loads to the cover less than a predetermined load, in which the biasing means is capable of being overcome by loads in excess of the predetermined load in order to allow relative movement of the deflator to its tyre deflating configuration.

15. A device as claimed in claim 14, in which the cover is incorporated into part of a tyre engaging surface of a ramp.