GB2368869A

GB2368869A - Road vehicle halting device

Info

Publication number: GB2368869A
Application number: GB0025219A
Authority: GB
Inventors: Roy Basil Walter Lowndes
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-10-14
Filing date: 2000-10-14
Publication date: 2002-05-15
Anticipated expiration: 2020-10-14
Also published as: GB0025219D0; GB2368869B

Abstract

The road-vehicle halting device includes a mounting part, mounting means each for mounting a vehicle tyre engaging spike 16 which is adapted upon impinging upon a vehicle tyre to be released from the mounting means, each spike including a base end 18 which is engaged with the mounting means, and with a pointed end which is use punctures the tyre, characterised in that the spike is made in use of a hardened metal which has been machined to a spike. The spike may be machined to the spike configuration with the metal in a soft state after which the spike is then hardened or alternatively the metal may be hardened after which it is machined to the desired shape, and the spike may be formed by an automated machining method. The spike may be generally conical from the base end to the pointed end and one or more formations may be formed in the exterior surface of the spike to act as bards to assist in retaining the spike in a tyre which it has punctured. The spike is preferably hollow with one or more openings 23 from the exterior wall allowing the passage of air into the hollow to allow air to escape from the tyre to the atmosphere through a hollow in the base. The spike may have a continuously decreasing cross-section from the base to the pointed end and may have a base which is machined with a reduced cross-section to provide a step 19 which engages the top surface of the mounting means. The spike may be formed in a twisted configuration with the twist progressing around a generally central axis of the spike.

Description

Title: Vehicle Halting Device Description of Invention This invention relates to a road-vehicle halting device of the kind which is intended to be deployed in the path of the vehicle, and which has plurality of vehicle tyre engaging spikes which are adapted to puncture vehicle tyres.

There have been several proposals for such devices. One commercially successful device is described in US patent A-5536109.

In this prior proposal, the device includes a plurality of arms, some of which have secured thereto cups which releasably retain tyre engaging spikes.

As a vehicle tyre impinges upon the spikes, the spikes are removed from the plastic cups as they puncture the tyre.

The spikes are generally triangular in cross section, with the cross section of the spike decreasing to a point, from a base end which is received by the cup. The spikes each have a central hollow, with openings from sides of the spikes in to the hollow, to allow the passage of air through the spike, as the spike punctures the vehicle tyre. Conventionally, such spikes have been made very economically by casting in zinc or zinc alloy, as such metal is relatively soft, and the edges of the triangular section can readily be sharpened. However it has been found that such conventional spikes may not reliably puncture tyres produced by modem technology, which may include metal bracing and the like.

Accordingly it is an object of the present invention to provide a roadvehicle halting device with new or improved vehicle tyre engaging spikes.

According to one aspect of the invention I provide a road-vehicle halting device including a mounting part, mounting means each for mounting a vehicle tyre engaging spike which is adapted upon impinging upon a vehicle tyre to be released from the mounting means, each spike including a base end which is engaged with the mounting means, and a pointed end which in use first punctures the tyre, characterised in that the spike is made of a hardened metal which has been machined to the spike configuration.

The spike may be machined to the spike configuration with the metal in a soft state and the spike configuration subsequently hardened, or hardened metal may be machined to the spike configuration.

In each case, a spike may be produced which is able to puncture tyres which conventional cast spikes are unable to puncture.

It will be appreciated that conventional cast spikes are prone to shattering or breakage where encountering a vehicle tyre the spike is unable to puncture, whereas a machined spike of a hardened material is less prone to breakage and is more efficient at puncturing all tyres.

From an economical point of view, a spike for a device in accordance with the invention need not be prohibitively expensive if made by, for example, a modem automated machining method, such as using a CNC machine.

The spike may in one example be generally conical from the base end to the pointed end, although in another example, the spike may have provided in an exterior wall thereof, one or more formations to act as barbs to assist in retaining the spike in engagement with the tyre once having punctured the tyre.

Thus the considerable air pressures to which the spike may be subjected from the inside of the tyre, may be resisted by the formations. In any event, preferably like a conventional spike, the spike may be hollow with one or more openings from the external wall of the spike to the hollow, to allow for the passage of air from the tyre, through the opening or openings to the hollow and hence to atmosphere, through a passage provided in the base.

The spike may be of a continuous decreasing cross section from the base end thereof to the pointed end, or the base end may be machined to a reduced cross section to provide a step which prior to the spike being released from the mounting means, engages a top surface of the mounting means. Where the base end of the spike is otherwise of a large cross section, such a step can assist in supporting the spike in the mounting means as the pointed end of the spike impinges upon the vehicle tyre, thereby deterring the likelihood of the tyre merely removing the spike from the mounting means without puncturing the tyre.

In another arrangement, instead of the spike being generally conical, the spike may be machined to a twisted configuration, with the twist progressing around a generally central axis of the spike. Such a configuration may cause the spike to rotate as the spike impinges upon the tyre, to assist in driving the spike into the tyre. Such a twisted configuration spike, may have a central hollow and openings in the external wall thereof to allow for the passage of air from the tyre, or by virtue of the configuration of the twist, air may pass from the tyre.

According to a second aspect of the invention I provide a tyre engaging spike for use in the device of the first aspect of the invention, the spike being adapted upon impinging upon a vehicle tyre to be released from the mounting means, each spike including a base end which is engaged with the mounting means, and a pointed end which in use first punctures the tyre, characterised in that the spike is made of a hardened metal which has been machined to the spike configuration.

The invention will now be described with reference to the accompanying drawings in which: FIGURE 1 is an illustrative perspective view of a road-vehicle halting device in accordance with the invention; FIGURE 2 is an illustrative side view of a first configuration spike; FIGURE 3 is an illustrative side view of a second configuration spike; FIGURE 4 is an illustrative side view of a third configuration spike; Referring to figure 1, part of a road-vehicle halting device 10 in accordance with the invention includes a plurality of arms 11, 12 etc. which are pivotally interconnected in a generally scissors-like configuration. The device 10 is shown in an unfolded condition in which the device 10 will be when deployed in the path of a vehicle to be halted.

Each alternate arm 12, etc. provides a base which has a plurality of mountings 15, which in this example are plastic cups, which mount spikes 16 which in use impinge upon and puncture the tyres of a vehicle which is driven over the device 10.

In this example, the arms 11,12 etc. are metal, and the cups 15 are secured to the arms 12 etc. by fasteners, although in another example, the arms may be provided in a moulded material such as a plastic material, and the cups 15 may integrally be provided.

In each case, when a spike 16 impinges upon a vehicle tyre and punctures the tyre, the spike 16 will be removed from its cup 15 as the tyre continues to roll over the device 10.

Referring to figure 2, a spike 16 is shown which is of a generally conical configuration, a base end 18 of the spike 16 being of reduced cross section so that there is a step 19 in a conical exterior wall 20 of the spike 16 which in use, prior to release from the cup 15, engages with a top surface 21 (see figure 1) of the cup 15. Such support for the spike 16, deters the likelihood of the spike 16 being removed from the cup 15 without puncturing the tyre.

The spike 16 is hollow, the hollow opening from the base end 18 of the spike 16 and there is an opening in the form of slot 23, axially along a substantial portion of the exterior wall 20 of the spike, from the exterior surface 20, to the internal hollow. Thus as the spike punctures a tyre, air may pass out of the tyre through the slot 23, to the hollow, and hence from the base end 18 of the spike.

The spike 26 is made in a hardened metal, such as hardened steel, e. g., steel conforming to EN8, or harder, by machining from stock to the configuration shown, utilising CNC automated machining. Thus the spike 16 is considerably stronger than conventional cast spikes, which are made in softer materials so that sharpened edges may be provided to help with puncturing the tyre. Preferably such hardened steel is machined to the configuration shown, although in another example, the spike configuration may be machined in a softer steel and subsequently hardened.

Another example of a spike in accordance with the invention is shown in figure 3. This is similar to the spike of figure 1 and made by a similar process.

However, there are provided a pair of slots 23 in the external surface 20 of the spike 16, to the interior hollow. Also, in this example, a pointed end 30 of the spike 16, is provided at an angle less than the cone angle, by machining.

In figure 4, another similar spike 16 is shown, but as the cone angle of the spike is less than with the figures 2 and 3 examples, no step is provided, adjacent the base end 18, as shown at 19 in figures 2 and 3. However the base end 18 is provided with a cylindrical part 25 which in use is received in the cup 15. Again the spike 16 is made in a hardened metal by machining to the configuration shown.

In another example (not shown), a spike may be machined with one or more barb-like formations on the exterior surface 20 thereof, such formations serving to retain the spike 16 in the tyre, when the tyre has been punctured, where exposed to a substantial pressure from the interior of the tyre which may otherwise urge the spike 16 from the tyre.

In yet another example, (not shown), a spike 16 may be machined with a twisted or helical exterior wall, so that the spike tends to rotate as it enters the tyre to assist driving the spike into the tyre.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS 1. A road-vehicle halting device including a mounting part, mounting means each for mounting a vehicle tyre engaging spike which is adapted upon impinging upon a vehicle tyre to be released from the mounting means, each spike including a base end which is engaged with the mounting means, and a pointed end which in use first punctures the tyre, characterised in that the spike is made of a hardened metal which has been machined to the spike configuration.
2. A device according to claim 1 characterised in that the spike is machined to the spike configuration with the metal in a soft state and the spike configuration subsequently hardened.
3. A device according to claim 1 characterised in that hardened metal is machined to the spike configuration.
4. A device according to any one of the preceding claims characterised in that the spike is made by an automated machining method.
5. A device according to any one of the preceding claims characterised in that the spike is generally conical from the base end to the pointed end.
6. A device according to any one of the preceding claims characterised in that the spike has provided in an exterior wall thereof, one or more formations to act as barbs to assist in retaining the spike in engagement with the tyre once

having punctured the tyre.

Z : l
7. A device according to any one of the preceding claims characterised in that the spike is hollow with one or more openings from the exterior wall of the spike to the hollow, to allow for the passage of air from the tyre, through the opening or openings to the hollow and hence to atmosphere, through a passage provided in the base.
8. A device according to any one of the preceding claims characterised in that the spike is of a continuous decreasing cross section from the base end thereof to the pointed end.
9. A device according to any one of claims 1 to 8 characterised in that the base end is machined to a reduced cross section to provide a step which prior to the spike being released from the mounting means, engages a top surface of the mounting means.
10. A device according to any one of claims 1 to 4 characterised in that the spike is machined to a twisted configuration, with the twist progressing around a generally central axis of the spike.
11. A road-vehicle halting device substantially as hereinbefore described with reference to the accompanying drawings.
12. A tyre engaging spike for use in the device of any one of the preceding claims wherein the spike is adapted upon impinging upon a vehicle tyre to be released from the mounting means, each spike including a base end which is engaged with the mounting means, and a pointed end which in use first punctures the tyre, characterised in that the spike is made of a hardened metal which has been machined to the spike configuration.
13. A spike substantially as hereinbefore described with reference to and as shown in figure 2 or figure 3 or figure 4 of the accompanying drawings.
14. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.