GB2285826A

GB2285826A - Retractable post assembly

Info

Publication number: GB2285826A
Application number: GB9500963A
Authority: GB
Inventors: Adolf Koch; Jurgen Meding; Leo Smyrek
Original assignee: MALKMUS DOERNEMANN CAROLA
Current assignee: MALKMUS DOERNEMANN CAROLA
Priority date: 1994-01-19
Filing date: 1995-01-18
Publication date: 1995-07-26
Also published as: DE4401312A1; GB9500963D0; FR2715176A1

Description

BOLLARD ASSEMBLY 2285826 The invention relates to a bollard assembly, for

example of the type which includes a bollard which can be lowered into a cavity.

Bollards are used to influence road traffic. They represent rising, relatively stable objects which, often arranged in a plurality in a line and spaced apart, are intended to bar unauthorised persons from travelling along a road, a path, etc. Examples of the latter are private paths, fire-brigade approaches, pedestrian zones, etc.

It is precisely in these exemplary cases that a permanent barrier is undesirable, as authorised persons (e.g. the owner, the fire brigade, deliverymen) must be able to pass through. For them to do so it must be possible to remove temporarily the obstruction constituted by the bollards. For this purpose the bollards can either be removed, swung back or lowered.

Lowering is a possibility if this is suggested by the shape of the bollard or the local conditions, but in particular also the size or the weight and the intended function of the bollard. For if the bollard is large or heavy it may be impossible to remove it or swing it back. In order to lower the bollard when it is acting as a barrier it is arranged centrally above a cavity whose cross-sectional shape is similar to, but larger than that of the bollard. The bollard can be lowered and deployed manually, pneumatically, hydraulically or electromechanically.

Heavy and/or large bollards in particular give rise to the problem of the bollard easily tilting in the cavity on account of the lever action if it is not guided with a precise fit. It is, however, not advisable to form the bollard and the cavity so as to achieve a precise fit, 1 2 bearing in mind, in the f irst place, the inconvenience of soiling caused by dust, leaves, etc., as encountered in the open. Secondly, a precise fit also entails prohibitive costs. The aim is rather to produce bollards and cavities inexpensively using simple means, and this results in shapes which are not ideal. It should also be borne in mind that motor vehicles quite often run against bollards as a result of a deliberate or inadvertent action and the resulting damage should - to a certain degree be tolerable.

Tilting greatly hampers manual or mechanical operation or even makes it impossible. If the distance between the surface of the bollard and the wall of the cavity is too small, the additional problem of the bollard becoming jammed in the cavity due to excessive friction occurs. If, on the other hand, the distance is too great, the bollard may move horizontally, so that it may tilt if it is not moved exactly vertically.

The present invention seeks to provide an improved bollard assembly.

According to an aspect of the present invention, there is provided a bollard assembly comprising a bollard, a housing including an inner wall forming a cavity, into which the bollard can slide, and a plurality of guide members provided between the bollard and the cavity wall so as to support the bollard against the wall of the cavity.

It is possible to provide with some embodiments an assembly with a bollard which can be lowered into a cavity and which is less susceptible to tilting.

Preferably, there are provided at the circumference of the bollard spaced, vertically extending guide bars which support the bollard against the wall of the cavity.

An arrangement of this kind can make it unnecessary to form the bollard and the cavity so as to produce a precise fit. It may simply be necessary to ensure that there is contact between the guide bars and the wall of the cavity. The risk of the bollard becoming jammed can be reduced to an exceptional degree by a greatly reduced friction surface.

It is particularly advantageous if the guide bars secured to 1 y, for example by the bollard can be displaced horizonta11 threaded spindles, so that the guides can be adjusted, for example, when a bollard is f irst fitted in a cavity or in accordance with the wear of the material used for the parts 3 of the guide bars which are in contact with the wall of the cavity. Thus, it is possible to provide bollards to be guided in cavities which can be inexpensively, yet inexactly produced, as the guide bars can be individually adapted to the circumstances by displacement. The service life of the guides can also be extended considerably by making adjustments every now and then. according to the wear at the points of contact with the wall of the cavity, so that guidance free from play is again guaranteed.

it is of particular advantage if at least the material of the parts of the guide bars which are in contact with the wall of the cavity is a sliding material, for example a polyamide. Sliding materials are distinguished by good sliding properties and by the fact that they are yielding materials. By using a material of this kind the bollard can be guided in the cavity with an easy notion, yet no play and thus precisely.

When using bollards with, for example, a round or an oval cross section, it is particularly advantageous for the guide bars to have a T-shaped cross section, so that only the outermost two edges of the T-shaped guide bars are in contact with the wall of the cavity. The guidance at each guide bar thus only takes place along two edges, resulting in exact guidance, extremely low friction and slight wear of the materials which are used.

If the space between the bollard and the wall of the cavity is closed off level with the ground at the top by an annular disc, this counteracts the penetration of particles of dirt and dust into the cavity. The device can as a result operate for longer without requiring maintenance.

In the case of bollards with a circular cross section, it is sufficient if this is permitted by the weight of the bollard - to use just three vertical guide bars arranged at the circumference of the bollard such that they are each staggered by 1200. This static three-point support provides 4 an inexpensive solution which can save material.

In order to reduce costs and for the optical effect, it is advisable for the guide bars only to extend over the part of the bollard which is still in the cavity when the bollard is completely deployed, as it is only in this region that the bollard is held when deployed and good guidance can thereby be guaranteed.

As an alternative to guide bars arranged on the bollard, it is also possible to arrange these on the inside of the wall of the cavity. This gives rise to a reversal of functions; the bars now remain in their position, while the bollard is supported against then.

Tn another embodiment, there is provided on the inside of the wall of the cavity spaced, vertically extending guide bars against which the bollard or devices surrounding the bollard in the form of rings is/are supported.

In this embodiment it is preferable to provide on the outside of the bollard ring-shaped guide devices which comprise groove-like recesses for the guide bars. Either the bars are supported in the groove-like recesses or the outside of the rings slides along the inner wall of the cavity. The first of these two alternatives is preferred.

It is particularly preferable for the material of the parts of the guide bars which are in contact with the bollard and/or the material of the guide devices surrounding the bollard in the form of rings to be a sliding material, for example a polyamide. This can provide the advantage of low friction contact between the parts of the assembly which make sliding contact with one another.

The overall alternative embodiment with the guide bars placed on the inside of the cavity has advantages when applied to bollards which must be equal to particular collision loads. The contact surface of the rings, which extends over a greater area with respect to the inside, which is then entirely available, of the wall of the cavitycan also stabilise these bollards against substantial loads and thus can justify the somewhat higher costs entailed by the additional expenditure on construction.

The concepts of the other preferred embodiments can in each case be applied to one another in some cases with a reversal of functions.

An embodiment of the present invention is described below, by way of example only, with reference to the accompanying drawings, in whij-h:

Figure 1 shows an embodiment of a bollard with a circular cross-section which can be lowered and is provided with guide bars; Figure 2 is a cross-sectional view through the bollard arrangement of Figure 1; Figure 3 is an enlarged detail from Figure 2 showing in cross-section a T-shaped guide bar; Figure 4 is a horizontal section through a second embodiment of a closing- off device; Figure 5 is a vertical section through the device of Figure 4.

Figure 1 shows a bollard 1 which has a circular cross section and can be lowered into the ground. It is disposed in a cavity 3, which surrounds it concentrically and in which it is guided by spaced guide bars 2 which extend vertically, thus in the axial direction, and are arranged at the circumference of the bollard 1.

Figure 1 shows the bollard 1 when completely deployed. The 6 cavity 3 is preferably at least of a depth so as to accommodate the bollard 1 when the latter is completely lowered. In order to ensure that it is held in a stable manner, a certain part of the bollard 1 remains in the cavity 3 when it is completely deployed. The guide bars 2 only extend over the part of the bollard 1 which remains in the cavity 3 when the bollard 1 is completely deployed.

Experimental bollards which have proved highly reliable and efficient were 1085 mm long with the cavity 3 being approximately 1180 mm long. When the bollard 1 was deployed.approximately 225 mm, of the latter, less than one third, remained in the cavity 3.

The guide bars 2, also being 225 mm long, only extend over the lower region R the bollard 1.

The guide bars 2 may be moved horizontally (towards or away f rom the walls of the cavity 3) by threaded spindles 4, so that the guide bars 2 can be adjusted, for example when a bollard 1 is first fitted in a cavity 3 or in accordance with the wear of the material used for the parts of the guide bars 2 which are in contact with the wall of the cavity 3.

The guide bars 2 are connected to the bollard 1 in the region of the threaded spindles 4 and therefore not over their entire vertical extent.

A sliding materiall for example a polyamide, is a particularly advantageous material for the guide bars 2. At least the parts of the guide bars 2 which are in contact with the wall of the cavity 3 are preferably produced from a material of this kind. on account of their good sliding properties and a certain flexibility, sliding materials are well suited for providing precise guidance with an easy motion. Alternatively, the guide bars 2 may be provided with a rolling surface.

It is also particularly advantageous for the guide bars to have a T-shaped cross section, so that only the outermost two edges 6 of the guide bars 2 are in contact with the wall k, 7 of the cavity 3. The guidance at each guide bar thus only takes place along two edges, resulting in exact guidance with low friction and slight wear of the sliding material. Any other shape or arrangement may be provided for reducing the area of contact of each guide bar 2 with the cavity wall.

The illustrated embodiment has three guide bars 2 which are each staggered by 1200. It is, however, also possible to use more than three guide bars 2, particularly when the bollards 1 are very heavy, large or shaped in another way.

The space between the bollard 1 and the wall of the cavity 3 is closed off level with the ground at the top by an annular disc 5 in order to reduce the penetration of foreign matter into the cavity.

Figures 4 and 5 show a second embodiment of bollard assembly. It can be seen that in this case the guide bars 2 are arranged on the inside of the wall of the cavity 3 and again extend vertically.

In the represented embodiment)the actual bollard 1 is provided with two ring-shaped guide devices 7, both preferably formed from a sliding material, for example a polyamide. These guide devices 7 comprise groovelike recesses 8, which extend vertically and in which the bars 2 of this embodiment extend. Additional groove-like recesses 8 may be provided during manufacturing, Figure 4 showing that no bars extend in these. These bars 2 enable the closing-off device to be drained and cleaned more easily.

Drainage channels 9 at the bottom of the cavity 3 carry off any surface water flowing in. A lifting mechanism 10 at the bottom of the cavity is also indicated, this being of any suitable type known to the person skilled in the art.

8

Claims

CLAIMS:

1. A bollard assembly comprising a bollard, a housing including an inner wall forming a cavity into which the bollard can slide, and a plurality of guide members provided between the bollard and the cavity wall so as to support the bollard against the wall of the cavity.

2. A bollard assembly according to claim 1, wherein the guide members extend f rom a periphery of the bollard towards the cavity wall.

3. A bollard assembly according to claim 2, wherein the guide members extend only over a part of the bollard which remains in the cavity when the bollard is fully extended.

4. A bollard assembly according to claim 1, wherein the guide members extend from the cavity wall towards the centre of the cavity.

5. A bollard assembly according to claim 4, wherein the bollard includes a guide device supported thereon, the guide members cooperating with the guide device.

6. A bollard assembly according to claim 5, comprising two guide devices supported on the bollard.

7. A bollard assembly according to claim 5 or 6, wherein the or each guide device is in the form of a ring extending around the bollard.

8. A bollard assembly according to any preceding claim, wherein at least one of the parts of the bollard assembly which makes sliding contact with another part is formed from a sliding material.

9. A bollard assembly according to claim 8, wherein the 9 sliding material is a polyamide.

10. A bollard assembly according to any preceding claim, wherein the parts of the bollard assembly which make sliding contact with one another are shaped such that only two outermost edges of each guide member contact the wall of the cavity or bollard.

11. A bollard assembly according to any preceding claim, wherein the guide members are adjustable in a direction towards or away from the cavity wall or bollard.

12. A bollard assembly according to claim 11, wherein the guide members include threaded spindles or spring elements for providing adjustment of the guide members.

13. A bollard assembly according to any preceding claim, comprising three guide members spaced substantially 1200 from one another in the cavity.

14. A bollard assembly according to any preceding claim, wherein the housing includes an angular cover plate between the opening of the cavity and the bollard.

15. A bollard assembly substantially as hereinbef ore described with reference to and as illustrated in Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.