GB2490118A

GB2490118A - Bollard assembly for preventing vehicular access

Info

Publication number: GB2490118A
Application number: GB1106499.5A
Authority: GB
Inventors: Chris Rowlands; Roger Philip Knight
Original assignee: APT Controls Ltd
Current assignee: APT Controls Ltd
Priority date: 2011-04-18
Filing date: 2011-04-18
Publication date: 2012-10-24
Also published as: GB201106499D0

Abstract

The bollard assembly comprises a bollard 11 and a base plate 12,13, the bollard including a first portion sized to pass through an opening in the base plate and a second portion sized to prevent passage through the opening. The opening may be chamfered with the bollard comprising a corresponding chamfer to engage the openingâ s chamfer. The base plate may comprise first and second plates which engage the bollard at different locations along its length. The bollard may comprise a bollard shaft 11a and a collet 14, the collet having an opening to receive the bollard shaft and an outer portion sized to prevent passage of the collet through the opening. The base plate may comprise a first array of elongate openings 131 for receiving fixing elements so as to allow movement of the bollard in the event of an impact and a second array of non-elongate openings for static fixing of the bollard.

Description

I

SAFETY BOLLARD

The present invention relates to safety bollards for preventing passage of a vehicle or other body of large mass. In particular, the invention relates to an impact resistant bollard arranged to be mounted to a surface without the need for submerged foundations or the related excavation works.

Bollards are often mounted in the ground in a spaced configuration for preventing the passage of large vehicles, while allowing the passage of smaller bodies, such as a pedestrian or bicycles. Alternatively, if it is desired to prevent the passage of all traffic, be it pedestrian, bicycle or large vehicle traffic, then bars, wires or chains may be attached or suspended between lines of adjacent bollards which are mounted in the ground. Increasingly, an anti-terrorist, security or safety function is desirable in bollards and their design must therefore allow for them to resist the impact of a vehicle or other mobile body of large mass to prevent passage of the object in order to prevent it from approaching and/or impacting buildings or other structures located behind the bollards.

Conventionally, such impact resistant bollards are put in place by use of relatively deep foundations, which must be buried under the ground, generally in a settable material such as concrete, at required depths of generally over 0.25 metres and in some instances at much greater depths than this. The creation of such foundations requires a great deal of heavy machinery, intensive labour and specialist tools and equipment in order to install impact resistant bollards, Further, these known bollard installations require a large amount of work to remove the bollards and repair the surface if they are subsequently removed.

A need has been identified for an impact resistant bollard assembly which may be mounted to a surface without the need for foundations which are buried deep under the surface around the bollard. Such a surface-mountable bollard assembly can be temporarily installed and removed after use with minimal requirement for deep excavation of foundations and repair of the ground afterwards. Simple repair of the surfacing, such as re-filling holes for e.g. bolts, may be all that is necessary after the bollard is removed, and in some instances no re-work of the surface is necessary at all and the bollard assembly may be re-installed and removed many times without the need for ground works. In certain cases, the mounting assembly of a surface mounted bollard may be concealed under a shallow surface preparation such as tarmac, paving or another relatively shallow surface preparation without the need for deep excavation works.

According to the present invention there is provided an impact-resistant bollard assembly comprising: a bollard for resisting an impact; and a base plate having first and second sides; the bollard comprising: a first portion, sized and dimensioned to pass through the opening in the base plate and extending away from the base plate to protrude from the second side of the base plate; and a second portion sized and dimensioned to prevent its passage through the opening in the base plate from the first side to the second side, to prevent extraction of the bollard from the base plate in the direction of the second side of the base plate.

An impact resistant bollard assembly configured in accordance with the present invention provides an efficient structure, requiring a minimum of parts and which may be mounted to a surface with a minimum of distuibance of the surface to which the bollard assembly is mounted. The base plate of the invention may be attached to the surface by suitable attachment means as necessary, for example, bolts, rivets, screws, stakes, or pins, which may be inserted into the ground or other surface to which the bollard assembly is attached, by conventional methods. The provision of a bollard comprising a first portion which may pass through the opening in the base plate, and a second portion which may not, means that the configuration of the bollard itself prevents extraction of the bollard from the base plate upon impact on an upper part of the bollard. This can reduce the need to rely upon any securing or fixing means provided between the bollard and the base plate, such as welds, pins or bolts, so that these fixing elements do not create stress concentrations and resulting areas of weakness in the assembly which may result in catastrophic failure of the bollard assembly, thus preventing it from performing its function of withstanding an impact.

The second portion of the bollard may have a width or diameter greater than that of the opening. In the case that the bollard is of circular profile, providing a portion of greater diameter than the main column of the bollard which may not pass through the base plate is an efficient manner of creating the desired link between the bollard and the base plate.

The bollard may be fixed to the opening in the base plate by means of nuts, bolts, welding, rivets, a pin or other fixing means. This increases the security of the connection between the bollard and the base plate to prevent the bollard being removed upon impact and can stabilise the assembly during installation and normal use.

The opening in the base plate may comprise a chamfer and the bollard may comprise a corresponding chamfer to engage the chamfer of the base plate. Using a chamfer between the bollard and the base plate may increase the area of contact between the bollard and the base plate, thus reducing areas of stress concentration, which in turn may reduce any large deformations of each part of the assembly as energy is absorbed within each part of the assembly upon an impact on the bollard. A chamfer as defined herein may comprise a continuous linear transition between, for example, a larger diameter and a smaller diameter of a shaft, or a larger width and a smaller width of a part of the bollard assembly. The chamfer may be non-linear, having a curved profile and the chamfer may comprise relatively sharp angles at each of its ends, or may optionally have smooth transitions at either or both of its ends.

The bollard assembly may comprise first and second base plates arranged at different axial locations along the bollard, the bollard passing through an opening in at least one of the base plates. This arrangement allows a two-part base plate arrangement to be used, where a base of the bollard may be retained by either one or both of the base plates. The end extremity of the bollard may be accommodated in either a recess in, or an opening extending through, one of the base plates, while a second base plate may comprise the opening through which the second portion of the bollard is unable to pass.

This can allow the provision of a first base plate of smaller dimensions, which comprises the opening through which the second portion of the bollard is unable to pass, while a separate base plate can provide a larger surface area over which the assembly is mounted to the ground or other surface. This allows distribution of forces across a greater areas without the need for such a thick base plate as would be required if a single base plate were used to provide both the opening for retention of the second portion of the bollard and to distribute forces across the surface to which the assembly is mounted.

The bollard may pass through openings in each of the first and second base plates, to distribute forces between each of the two plates.

The first and second base plates may be spaced from one another. This can allow the reaction forces of either or both of the base plates to be distributed along a longer axial length of the bollard shaft. This can improve impact resistance and energy absorbance of the assembly as impact forces are distributed through a greater part of the bollard and resulting mechanical advantages of the respective base plates, may be increased to reduce stresses upon them.

Alternatively, the second base plate may be located on the first base plate and directly connected thereto, which creates a more compact assembly and can result in a more secure connection between the base plates.

The second base plate may be integrally formed with the first base plate, which may provide the advantages of the two plate arrangement, without the need for separate parts in the assembly.

The bollard of the bollard assembly may be a two-part bollard comprising a bollard shaft, a collet and securing means for securing the collet to the bollard shaft; the collet having an opening arranged to receive the bollard shaft and an outer portion sized and dimensioned to prevent passage of the collet through the opening in the base plate(s). If, for example, a bollard of the invention is created from a single piece of material having a wider diameter and a smaller diameter, a great deal of turning-down of the shaft would be required and would result iun a large amount of waste material. Providing a two-part bollard as described allows the desired form to be created from a two-part assembly, which results in less waste of material and a more efficient construction.

The collet may further comprise a second opening for receiving securing means for securing the collet to the bollard shaft. In this way, securing means such as a pin, bolt, screw or rivet may be provided to increase the strength of the connection between the collet and the bollard shaft, to retain the bollard shaft within the assembly upon impact. This may be in addition to, or instead of, a fixing such as weld, thread or adhesive joint between the collet and the bollard shaft.

The bollard shaft may comprise an opening for receiving the securing means, which opening may extend entirely through the bollard shaft. This allows a pin to be inserted through the bollard shaft and the collet to provide a secure connection between these two parts of the assembly.

The pin may therefore pass from a first side of the collet through the bollard shaft to a second side of the collet.

The bollard assembly may further comprise pin securing means, such as at least one weld, threaded means, or clip means for securing the pin within the collet and/or the bollard shaft.

The base plate may comprise openings for receiving fixing means for fixing the assembly to a surface. These fixing means may be pins, screws, or rivets of other suitable means for fixing the assembly to the surface in question.

The openings may be elongate. The provision of elongate openings can allow the assembly to be mounted to a ground or surface in a manner such that upon impact on the bollard in an expected direction, the assembly may be displaced relative to the surface and the fixing means, since the fixing means may be displaced within the elongate openings. This displacement of the assembly can allow energy of the impact to be absorbed in the friction forces between the fixing means, the plate and ground and the by the deformation/breaking down of any surfacing material which may be located over the base plate. All of these factors, both separately and in combination can improve the impact absorbance of the assembly.

The base plate may comprise: a first array of elongate openings for allowing movement between the assembly and the surface and fixing means to which the assembly is mounted; and a second array of non-elongate openings for allowing substantially static fixing of the base plate to an adjacent base plate.

The assembly may therefore be fixed to the ground by fixing means located in the elongate openings, the elongate openings arranged such that the impact of a body on the bollard causes the assembly to be displaced relative to the ground and the fixing means, the fixing means being displaced within the elongate openings to absorb energy of the impact. The openings may be elongate and oriented in an expected direction of impact upon the bollard.

A bollard assembly array may comprise a plurality of bollard assemblies according to any one of the preceding claims, the base plates of adjacent bollard assemblies being connected to one another by removable connecting means.

Adjacent base plates may be connected by connecting strips comprising at least one non-elongate opening for static connection to a first base plate and at least one elongate opening for adjustable connection to a second base plate.

The fixing means may be at least one bolt, rivet, pin or other fixing means suitable for location in an elongate opening.

Specific embodiments of the invention will now be described with reference to the following figures in which: Figure 1 shows a side section of a bollard assembly according to the present invention; Figure 2 shows a section of a bollard assembly according to the present invention viewed along the axis of the bollard; Figures 3A, 3B and 3C show a collet for use in the assembly of present invention; Figure 4 illustrates optional arrangements of elongate openings in the base plate of the present invention.

Figure 5 illustrates an arrangement of a plurality of bollard assemblies according to the present invention; and Figure 6 shows a strip for fixing base plates of the invention to one another.

Figure 1 shows an impact resistant bollard assembly according to the present invention. The assembly 1 comprises a bollard 11, a first base plate 12 and a second base plate 13. In this particular arrangement, the bollard 11 comprises collet 14, which is secured to the bol lard shaft 1 la via a pin 15 passing through holes in both the bollard shaft 1 la and the collet 14.

As illustrated in the figure, the bollard comprises a first portion, sized and dimensioned to pass through an opening 16 in base plate 12, and extending away from the base plate to protrude from the second side of the base plate, The bollard further comprises a second portion 1 ib, which is sized and dimensioned to prevent its passage through the opening 16 in the base plate from a first side I 6a of the base plate to a second side 1 6b of the base plate, to prevent extraction of the bollard 11 from the base plate in the direction of the second side 1 6b of the base plate in the event of an impact on the bollard 11 in particular.

Ends 151 of pin 15 may be welded to collet 14, may comprise a screw-threaded, or be fixed by any other means to prevent removal of the pin from the collet and the bollard shaft 11 a. First plate 12 may be located upon and directly connected to second plate 13, or alternatively spaced from plate 13, or these two plates may be integrally formed from a single plate, which may be of greater thickness than a single one of the illustrated plates. Openings 131 are provided in the base plate(s) and may be configured to receive any suitable fixing means, such as nuts, bolts, pins, rivets, or other suitable fixing means.

Bollard 11 as shown in Figure 1, comprises a separate collet 14 to provide the second portion of the bollard sized and dimensioned to prevent its passage through the opening 16 in the base plate 12. However, these two parts could be integrally formed from a single piece of material, removing the need for pin 151.

The bollard may be connected to either of the base plates 12 and 13 via welds 132. Where the collet is used, it may additionally or alternatively be fixed to bollard shaft 11 a by welds 11 b.

In a particular configuration for resisting impact from vehicles of an approximate size of 7.5 tonnes travelling at 48km/h, a height H of the bollard may be approximately 1 meter and its diameter may be approximately 220 mm.

Bollard 11 may be constructed from a hollow pipe having a wall thickness of approximately 20mm and less in some cases, while it may also be constructed from a solid shaft of any suitable material having the required strength for the expected impact.

Figure 2 shows a bollard assembly as shown in Figure 1 viewed along a longitudinal axis of the bollard.

The bollard assembly 1 comprises first and second base plates (12, 13) and a bollard 11. Pin 15 can be seen extending through collet 14 and bollard shaft ha, The illustrated section view in Figure 2 allows the internal features of bollard 11 to be seen, although in the actual product pin 15 would be substantially concealed within the bollard. Suitable dimensions for the base plates 12 and 13 may be 500 mm by 500 mm for plate 12 as illustrated by distances 201 and 202 in Figure 2. Base plate 13 may have dimensions of around 1500 mm in the direction of dimension 203 and 1400 mm in the direction of dimension 204. The bollard may be located approximately half way across a width of plate 13 in the direction of dimension 204. In this embodiment the centre line of bollard 11 is located approximately 400 mm from the closest edge of the plate 13, which equates to approximately a quarter of the length of the plate in the direction of dimension 203. An expected direction of impact on the bollard, in which it has greatest impact resistance, is in the direction of arrow 205, so that the part of base plate 13 extending away from the bollard in the direction of impact transfers forces from the impact to the ground away from the bollard, but impacts may be resisted from other directions as well.

An array of openings 131 is provided in plates 13. In this example, the openings are located 100 mm, or approximately 10% of the width and length of pkite 13, away from the edge of plate 13. The space in between openings in this example is between 200 and 210 mm, but may be approximately one bollard width or around 15% of the length 203 or width 204 of the plate 13. Plate 12 is approximately centred with respect to bollard 11. Plate 12 may have dimensions of approximately one third to one quarter of those of the plate 13 and in this example has dimensions of 500mm x 500mm.

Figure 3A shows an end view of collet 14 having a first part 141 sized and dimensioned to pass through the opening in base plate 12 and a second part 142 sized and dimensioned to prevent its passage through the opening in the base plate 12 from the first side 16a to the second side 16b of base plate 12.

Openings 143 are located in opposite sides of collet 14 for receiving pin 15. In the examples shown in Figures 3A to 3C, the second portion of collet 14, forming the second portion of the bollard 11 of the assembly, has a diameter greater than that of the opening in order to prevent its passage through the opening.

However, this larger diameter may be replaced by a larger width in the case of, for example, a square, or rectanguloid or substantially oval shaped bollard, whilst providing the same function.

Figure 36 shows a side view section of collet 14. The collet has an opening arranged to receive the bollard shaft having a dimension 144 corresponding to the external dimensions of the bollard shaft 11 a. In this case, as illustrated, the opening and the bollard shaft have a circular profile, however a rectanguloid, square, oval or otherwise shaped outer profile of each corresponding part may be envisaged. The first and second parts 141 and 142, respectively, can be seen as illustrated and described in Figure 3k The collet comprises a chamfer 145. In Figure 36, the chamfer is illustrated as a straight line connecting the outer parts of the first and second outer dimensions of the collet. The chamfer may be present on the bollard no coilet is used and the first and second parts are comprised entirely integrally with the bollard shaft ha.

The chamfer may be curved in a concave and/or convex manner and may be angled at a different angle relative to that shown in Figure 3B. The chamfer may be omitted such that a simple step change in diameter or outer width of the bollard is created and thus no chamfer is present. All of the above arrangements of chamfer 145 are therefore included in the definition of the term chamfer as used herein.

A secondary chamfer 146, located on the second portion of the bollard or collet as illustrated in Figure 36 may facilitate welding of the chamfered part to the base plate 12 or 13, while a chamfer provided at an opposite end to that illustrated in Figure 36 may help to round the corners of the collet to avoid injury to a user.

Figure 3C shows the collet 14 of Figure 3A, viewed from the opposite end, i.e. that of the second portion 142. Secondary chamfer 146, a substantially flat section 147 and a further internal chamfer 148 can be seen. Internal chamfer 148 can facilitate welding of the collet 14 to the bollard shaft ha.

Figure 4 shows an optional arrangement of the optionally elongate openings 131 of the previous figures. The openings 131 may be simple circular openings. However, as described previously, the provision of an elongate opening can allow increased slippage of fixing means within the elongate openings, to absorb energy of an impact on bollard 11, In the present example, the elongate openings are comprised of a pair of circular holes of diameter 19 mm. The distance 41 between centrelines of the holes 41 may be approximately 21 mm or approximately equal to, or greater than a diameter of the openings.

In the illustrated example, only a sub portion 42 of the material in between the two openings has been removed, leaving portions 43 of material projecting into the opening on the sides of the elongate opening. Accordingly, elongate openings are provided having a longitudinal axis 44 in the direction of elongation of the openings and a lateral axis in the direction of lines 45. The elongate openings may inward projections arranged to project into the openings in a lateral direction, to provide resistance to movement of fixing means located in the openings. Therefore, fixing means 46 having a diameter greater than the minimum width of the elongate opening in the direction of a lateral axis 45 will have to deform projections 43 in order to pass from one part of the opening to the other. This deformation will absorb energy in the case of an impact on the bollard and plate assembly in the direction of arrow 47. Alternatively, where it is desired to absorb less energy than is required to deform portions 43, the elongate openings may be provided with straight sides as illustrated by dashed lines 48.

Figure 5 shows a plurality of bollard assemblies of the present invention, arranged in a row and connected to one another by strips 51. Strips 51 may be more closely spaced at a location toward the direction of expected impact indicated by arrow 55 on base plate 13, and less closely spaced at a location away from the expected direction of impact 55. Base plates 13 may be provided with holes 50, which may be non-elongate holes to ensure a normally static engagement with the strip 51. The base plates may therefore be provided with a first array of elongate openings for allowing movement between the assembly and the surface and fixing means to which it is mounted and a second array of non-elongate openings for allowing static fixing of the base plates to one another. The non-elongate openings may be off-set relative to the elongate openings to avoid close arrays of stress concentrators and/or lines of stress concentrators along the base plate, which may cause weakness and points of potential failure of the base plate.

A spacing between adjacent base plates may be in the region of 20mm, or around 1%-5% of the base plate width 204 of Figure 2. The array of elongate openings of a base plate 13 may be split into two sub-arrays of openings 53 and 54, comprising a first sub-array 54 located around the bollard 11 and a second sub-array 53 located spaced away from the bollard in the expected direction of impact 50. This helps provide the required fixing while making efficient use of the fixing means where they are most needed on the base plate.

Figure 6 shows a strip 51 for use in connecting base plates 13 in detail.

The strip length may be around 0.6m or a third of the width 204 of base plate 13 to provide adequate connection between adjacent base plates. An array of holes 61 is provided to connect the strip to a first base plate and an array of elongate holes is provided to connect the strip to a second base plate 13. This allows adjustability of the connections between base plates 13. Elongate holes 62 may have a length 63 of around 4cm and a width of around 18mm for a strip length of 0.62m. The strip width 65 may be 6cm and the spacing 65 between centres of openings 61 and/or 62 in a longitudinal direction of the strip may be around 10cm. The holes in the strip may be spaced from one another along the longitudinal length of the strip and may further be arranged in longitudinal rows.

The above dimensions may be scaled up or down accordingly for different base plate and/or strip sizes.

Fixing means for placing in holes 50, 61 and 62 may be countersunk bolts, The bolts may be inserted from a lower side of base plate 13, which is oriented away from bollard shaft 11 a and may be welded to the base plate such that they protrude through base plate 13 on the side of base plate 13 which is adjacent bollard shaft 11 a. Strips 51 may then be attached to the bolts with nuts. Other similar fixing means may be envisaged, a benefit of countersunk bolts being that the heads lie flush with the side of the base plate 13 which will lie on the surface to which the plate will be mounted.

Claims

CLAIMS1. An impact-resistant bollard assembly comprising: a bollard for resisting an impact; and a base plate having first and second sides; the bollard comprising: a first portion, sized and dimensioned to pass through the opening in the base plate and extending away from the base plate to protrude from the second side of the base plate; and a second portion sized and dimensioned to prevent its passage through the opening in the base plate from the first side to the second side, to prevent extraction of the bollard from the base plate in the direction of the second side of the base plate.
2. A bollard assembly according to claim 1, wherein the second portion of the bollard has a width or diameter greater than that of the opening.
3. A bollard assembly according to claim 1, wherein the bollard is fixed to the opening in the base plate.
4. A bollard assembly according to claim 1, wherein the opening in the base plate comprises a chamfer and the bollard comprises a corresponding chamfer arranged to engage the chamfer of the base plate.
5. A bollard assembly according to claim 1, the bollard assembly comprising a first and second base plates arranged at different axial locations along the bollard, the bollard passing through an opening in at least one of the base plates.
6. A bollard assembly according to claim 5, wherein the bollard passes through openings in each of the first and second base plates.
7. A bollard assembly according to claim 5, the first and second base plates being spaced from one another.
8. A bollard assembly according to claim 5, the second base plate being located on the first base plate and directly connected thereto.
9. A bollard assembly according to claim 5, the second base plate being integrally formed with the first base plate.
10. A bollard assembly according to any preceding claim, the bollard comprising a bollard shaft, a collet and securing means for securing the collet to the bollard shaft; the collet having an opening arranged to receive a bollard shaft and an outer portion sized and dimensioned to prevent passage of the collet through the opening in the base plate.
11. A bollard assembly according to claim 10, the collet further comprising a second opening for receiving securing means for securing the collet to the bollard shaft.
12. A bollard assembly according to claim 11, the bollard shaft comprising an opening for receiving the securing means.
13. A bollard assembly according to claim 12, further comprising a pin passing from a first side of the collet through the bollard shaft to a second side of the collet.
14. A bollard assembly according to claim 13, further comprising pin securing means, such as at least one weld, threaded means, or clip means for securing the pin within the collet and the bollard shaft.
15. A bollard assembly according to any preceding claim, the base plate comprising elongate openings for receiving fixing means for fixing the assembly to a surface.
16. A bollard assembly according to claim 15, the base plate comprising: a first array of elongate openings for allowing movement between the assembly and the surface and fixing means to which the assembly is mounted; and a second array of non-elongate openings for allowing substantially static fixing of the base plate to an adjacent base plate.
17. A bollard assembly according to claim 15 or claim 16, the assembly being fixed to the ground by fixing means located in the elongate openings, the elongate openings arranged such that the impact of a body on the bollard causes the assembly to be displaced relative to the ground and the fixing means, the fixing means being displaced within the elongate openings to absorb energy of the impact.
18. A bollard assembly according to claim 17, wherein the fixing means is at least one bolt, rivet, pin or other fixing means suitable for location in an elongate opening.
19. A bollard assembly array comprising a plurality of bollard assemblies according to any one of the preceding claims, the base plates of adjacent bollard assemblies being connected to one another by removable connecting means.
20. A bollard assembly array according to claim 19, wherein adjacent base plates are connected by connecting strips comprising at least one non-elongate opening for static connection to a first base plate and at least one elongate opening for adjustable connection to a second base plate.
21. A bollard assembly substantially as described with reference to the accompanying figures.
22. A bollard assembly array substantially as described with reference to the accompanying figures.