GB2448324A

GB2448324A - Retractable post assembly

Info

Publication number: GB2448324A
Application number: GB0706882A
Authority: GB
Inventors: Melvyn Robert Cross; Keith Patrick Heaton
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-10
Filing date: 2007-04-10
Publication date: 2008-10-15
Anticipated expiration: 2027-04-10
Also published as: GB2448324B; GB0706882D0

Abstract

A retractable post assembly comprises two rigid members 1,3 connected together which are able to rotate around a fixed point 4 located in a structure that is mounted below the surface of a pavement or road 9. The intended purpose of the assembly is to provide a physical barrier to vehicle access, by means of member 1 presenting in a vertical position above surface 9. When member 1 is impacted by a vehicle at a force great enough to shear sacrificial pin 6, member 1 and member 3 will rotate around pivot 4. The rotational movement of member 1 and 3 is restricted to approximately 45 degrees by mechanical stops in the structure. The motion of the vehicle is intended to be arrested by a combination of member 1 and member 3 contacting the front and underside of the vehicle.

Description

A DYNAMIC SEOJRITY PJAIR1ER DEVICE The present invention relates to a

security barrier device that is intended to protect premises from damage by a vehicle by arresting the motion of the said vehicle and hindering its subsequent removal.

Ram raids have caused great concern in recent years. About the same value of stock is stolen in these incidents, compared to conventional burglary. but they lead to substantially greater repairs (some five times greater than in the average incident). (Criminal Statistics for England and Wales).

In addition to the problem of ram-raiding for the purposes of burglary there is also increasing concern regarding the use of a vehicle as a means of delivering a terrorist attack.

It is widely accepted that time is a key factor in preventing crime. Introducing a delay during the criminal act has been shown to be effective in preventing the act taking place and increases the chances of arrest. In the case of ram-raiding if the vehicle can be effectively stopped before impacting the target and render the vehicle unusable damage to property can be avoided and prevents the criminal from driving away before the police arrive.

The current method of providing protecting to property from ram raiding is by the use of fixed vehicle barriers. Although current vehicle barriers may deter the law-abiding and some criminals, many barriers can be overcome by excessive force. in the case of high-speed collision by a vehicle, or repeated ramming attempts.

The purpose of this invention is to provide a barrier around premises requiring protection that in normal circumstances appears identical to conventional barriers, but when impacted by a vehicle at a high force arrests the motion of the vehicle.

Preferably. this is achieved by means of a second member of the barrier unit that is substantially connected to a visible vertical member of the barrier, This vertical member is normally is in a position above the surface of the ground to provide a physical barrier to vehicle access.

Thus, when the vertical member is impacted. the vertical member rotates around a pivot, which is attached to a fabricated base structure set below the surface. The second member which is normally below the surface of the road or pavement rises upwards to a pre-determined position governed by the dimensions of the fabricated base structure, normally 45 degrees. This motion has two effects: the kinetic energy of the vehicle is absorbed during this motion: and a force is applied underneath the vehicle tending to lift the vehicle upwards.

The effect of this motion is to rapidly arrest the motion of the vehicle and to prevent the vehicle being driven in either a forward or reverse direction. This is due to the physical obstruction presented -. -3-by the vertical member and the horizontal member effectively impaling the under chassis of the vehicle.

Advantageously, a sprung loaded latch and corresponding locking tab / rebate or similar locking mechanism could be incorporated into the base unit to lock the horizontal and vertical members in their rotated position above the surface of the ground after impact. thus preventing the vehicle being physically removed.

Conveniently, the vertical member that represents the physical barrier to preventing passage of a unintended vehicle can be stored below the surface by sliding it downwards into the base unit below the ground. This will allow vehicles and pedestrians to freely pass over the unit if required.

Advantageously, the vertical member can be held in its position above the surface of the ground by the use of a locking mechanism.

such as a pin and a padlock. This prevents the unauthorized removal of the vertical member and subsequent undesired access by vehicles.

Preferably. the vertical barrier member and the second horizontal member it is connected to, is prevented from rotating by the use of a shear pin. This shear pin will be selected with a shear force great enough to prevent failure, and therefore activation of the barrier, by a low contact force, such as that exerted by a pedestrian or an accidental contact from a vehicle at a low speed. for example. during parking. The shear pin will also be selected to have a low enough shear force to fail when a large force is applied to the vertical member. such as during an impact by a vehicle.

In a alternative embodiment. other means could be used for the same purpose of the shear pin. For instance a mechanical clutch, a hydraulic cylinder or a large spring mechanism. The advantage of a spring mechanism. hydraulic cylinder or similar dampening mechanism is that it could also contribute to absorbing the kinetic energy of the vehicle after impact.

For convenience the vertical member can be provided with a handle to allow the member to be raised and lowered easily.

In this preferred embodiment the vertical member rotates around one axis by means of a cylindrical pivot pin located in the supporting base structure.

An alternative embodiment could consist of a spherical ball and socket joint allowing the vertical member free to move through a range of angular positions. This could be advantageous if impact from a vehicle is anticipated from a range of angles about the centerline of the vertical member.

A further alternative embodiment consists of a sensing mechanism: either electro-mechanical or electronic, that senses the movement of the vertical barrier and/or the second horizontal member. This sensing mechanism could be connected to a remote alarm system by physical wire * -5-connection or alternatively by a wireless connection such as bluetooth.

An example of dynamic security barrier constructed in accordance with the present invention will now be described in the following text and by reference to accompanying drawings.

Figure 1: is a perspective view of the security barrier device in its normal intended static position, prior to impact and providing a physical barrier; Figure 2: is a perspective view of the security barrier device illustrating the intended range of angular movement; Figure 3: is a perspective view of the security barrier unit, illustrating the means of collapsing the barrier: In figure 1 the barrier unit is comprised of base unit 2 which is intended to be a fabricated structure made from metal or a composite material or alternatively moulded or fabricated from a polymeric material. The base unit 2 is joined to base plate 7. and side plates 8, Typically base unit 2, side plates 8 and base plate 7 would be fabricated from steel plates normally at least 6mm thick. The plates would be typically welded together and treated with a anti-corrosion coating.

In figure 2, the horizontal member 3. is connected to side plates 8 by means of a pivot pin 4. Horizontal member 3 is free to rotate around pivot pin 4.

The vertical member 1 and horizontal member 3 would typically by constructed from steel plate of approximately 8mm in thickness. The plates typically would be welded to form rectangular sections and treated with a anti-corrosion coating. Additionally vertical member 1 may also have highly visible markings or a fluorescent coating applied to increase daylight or night-time visibility Alternatively, the vertical member 1 and horizontal member 3 could be a constructed from circular steel sections such as cold drawn and welded hollow tube.

Figure 1 shows vertical member 1 located in a opening in horizontal member 3. The vertical member 1 is restrained in position by locking pin 5. Locking pin 5 is secured in place in vertical member 1 by use of a padlock or alternative security device. Vertical member 1 is restrained from rotating in an anti-clockwise movement by the position of the rigid permanent feature 11 of base plate 2 and clockwise movement by shear pin 6.

In figure 1. the base unit is intended to be placed in a cavity below the road or pavement surface 9. The cavity will securely hold the structure 2 whilst allowing rotating of 3 and access to pins 6 for maintenance purposes. Alternatively the sub-surface unit could be housed within a enclosure that is secured in position below the surface. A temporary plate could also be included at the level of the surface 9 that would be displaced when member 3 is rotated due to impact on member 1.

In Figure 3. by using handle 12 member 1 can be lowered downwards into base unit 2 by removing pin 5 and lowering member 1 into opening 10 in member 3. Member 1 can be lifted upwards by use of handle 12 into the intended position above the ground surface 9. Member 1 can be securely held in the intended position by engaging locking pin 5.

Figure 1. Unattended removal of this pin can be prevented by use of lock 13.

Claims

(LAIMS 1. A vehicle barrier unit that consists of two or more members

which are substantially connected rotate around a fixed point to slow down or arrest a motion of a vehicle when impacted by said vehicle.

2. A vehicle barrier unit according to claim 1, in which at least one member of the unit is above the surface of the ground in which the unit is located.

3. A vehicle barrier unit according to claim 2. in which at least one member of the unit that is above the surface of the ground can be located within the unit structure that is below ground. to allow free access of pedestrians, cyclists or vehicles over the unit.

4. A vehicle barrier unit according to claim 2. in which one or more of the members that are connected to the member(s) above the ground are able to rotate about a pivot point located in a sub-surface structure.

5. A vehicle barrier unit according to claim 4. in which the force enabling the members to rotate is determined by a sacrificial mechanical fastener such as a shear pin.

6. A vehicle barrier unit according to claim 4. in which the force enabling the members to rotate is determined and limited by a dampening mechanism such as a spring, hydraulic cylinder.

mechanical or electrical clutch.

7. A vehicle barrier unit according to any preceding claims, in which the rotation of the unit is detected by a sensor and triggers a signal to a alarm or monitoring system.

210 8. A vehicle barrier unit according to claim 4 which incorporates a mechanism to lock the moving parts of barrier unit into a fixed position after the barrier has been impacted by a vehicle preventing removal of said vehicle.

9. A vehicle barrier unit according to any preceding claims, in which the sub-surface structure is housed within a enclosure that consists of a panel that is flush with the surface of the ground and is automatically displaced when the horizontal sub-surface 220 member is driven above the surface due to a force exerted on the above surface member causing it to rotate around its pivot point.

1O.A vehicle barrier unit substantially as hereinbef ore described and with references to the accompanying drawings.

Amendments to the claims have been filed as follows

I. A vehicle barrier unit for slowing down or arresting a vehicle comprising, a base unit, first and second members mounted to the base unit about a pivot, the first and second members being connected together, and means for preventing rotation of the first and second members about the pivot due to unintentional contact.
2. A vehicle barrier unit as claimed in claim 1, in which the means for preventing rotation of the first and second members about the pivot below a minimum force is a shear pin.
3. A vehicle barrier unit as claimed in claim 1, in which the means for preventing rotation of the first and second members about the pivot below a minimum force absorbs energy on rotation of the first and second members about the pivot.
4. A vehicle barrier unit as claimed in claim I or claim 3, in which the means for preventing rotation of the first and second members about the pivot below a minimum force is a clutch.
5. A vehicle barrier unit as claimed in claim I or claim 3, in which in which the means for preventing rotation of the first and second members about the pivot below a minimum force is a hydraulic cylinder.
6. A vehicle barrier unit as claimed in claim 1 or claim 3, in which in which the means for preventing rotation of the first and second members about the pivot below a minimum force is a spring mechanism.
7. A vehicle barrier unit as claimed in any preceding claim, in which the first member is movable relative to the second member between an operative position in which the first member extends substantially perpendicularly upwards from the 25 second member and away from the base unit and an in-operative position in which the first member is located substantially within the base unit. e.

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S. ..S * * ii 8. A vehicle barner unit as claimed in claim 7, in which a removable pin is inserted through aligned apertures in the first and second members for securing the first member in the operative position.
9. A vehicle barrier unit as claimed in claim 8, in which a lock is provided through the pin for preventing unauthorised removal of the pin.
10. A vehicle barner unit as claimed in any one of claims 7 to 9, in which a handle is provided for moving the first member between the operative and inoperatiVe positions.
ii. A vehicle barrier unit as claimed in any preceding claim, in which sensor means is provided for detecting rotation of the first and second members about the pivot.
12. A vehicle barrier unit as claimed in claim 11, in which an alarm is triggered by the sensor means on rotation of the first and second members about the pivot.
13. A vehicle barrier unit as claimed in claim 12, in which the alarm is remote from the vehicle barrier unit and is triggered throug1 a wireless network.
14. A vehicle barrier unit as claimed in any preceding claim, in which a spring loaded latch is provided for locking the first and second members to the base unit in a rotated position following impact of the vehicle barrier unit by a moving vehicle.
15. A vehicle barrier unit as claimed in any preceding claim, in which the pivot is * ** a ball and socket joint.

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16. A vehicle barrier unit as claimed in any preceding claim, in which the base unit, second member and the pivot are located substantiallY below ground level, the * first member is located substantially above ground level in an operative position, and S..

impact of the first member by a moving vehicle causes rotation of the first and second **.S members about the pivot for slowing down or arresting the vehicle. * *
17. A vehicle barrier unit as claimed in claim 16, in which the first member is located substantially below ground level when in an in-operative position and the upper facing surface of the first and second members and base unit are substantially level with the surface of the ground.
18. A vehicle barrier unit substantially as described herein with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings. * IS * * * ** S...

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