Deformable arrangement

Abstract

 The present invention relates to a deformable arrangement for securing an elongated post (10) or column to a fundament (11). The post or column has a longitudinal axis (A). The arrangement comprises: at least three screws (34), said each screw having a longitudinal axis (B) substantially parallel to the longitudinal axis (B) of the other screws and the longitudinal axis (A) of the post or column; guiding means (21); at least two substantially circular washers (33) for each screw (34; and a flange (30) extending substantially transverse to the longitudinal axis (A). The guiding means (21) are arranged on the outside periphery of the post or column and the flange (30) is arranged on the fundament, alternatively the flange arranged on the post or column and the guiding means on the fundament, said screws (34) are extending within said guiding means (21) and said recesses (31) and the flange (30) and the guiding means (21) clamped between the washers (33) in order to secure the post (10) or column to the fundament (11).

Description

Field of the invention

[0001] The present invention relates to a deformable arrangement for securing a post or column to a foundation.

Background of the invention

[0002] In order to increase the safety on the roads, for example lamp posts, traffic signs etc. are mounted along the roads. These posts, columns or traffic signs however constitute a considerable danger for the driver or passengers in a vehicle if they are accidentally hit by the vehicle. The danger increases with the speed of the vehicle.

[0003] There are today two different types of arrangements aiming to reduce the consequences that arise when these types of accidents occur are known. The first alternative is to use posts, or columns, that in a controlled manner reduce the speed of the vehicle. The second alternative is to use posts or columns that, when hit by the vehicle, immediately break way from the foundation and by the force applied by the vehicle continues up in the air before it finally falls down on the ground behind the vehicle that has continued forward. This category post or columns are normally called "slip base" or "break-away" posts or columns. The present invention relates to this category.

[0004] One break-away arrangement for securing a post is disclosed in Swedish patent nr SE500079C2. The disclosed arrangement comprises four screws arranged on the outside of the post parallel to the longitudinal axis of the post. The screws are used for securing the post to a foundation and when the post is hit by a vehicle, the post is slipped away from the foundation. The disclosed arrangement however suffers from some drawbacks since the desired slipping tend to not occur if the vehicle hit the post at a different height than the intended one, and furthermore the direction of the vehicle when it hit the post has proven to affect when the slipping takes place.

[0005] There is consequently a need for an improved fastening arrangement that reduces the risk for non-slipping of the post or column from the fundament when the post or column is hit by a vehicle.

Summary of the invention

[0006] The needs defined above are fulfilled by a deformable arrangement according to the definition in the independent claim.

[0007] The claimed deformable arrangement for securing an elongated post or column to a fundament comprises: at least three screws or bolts arranged around the outer periphery of the post, column or fundament, said each screw having a longitudinal axis (B) substantially parallel to the longitudinal axis (B) of the other screws and the longitudinal axis (A) of the post or column; guiding means arranged in relation to each screw, said each guiding means consist of two substantially flat rectangular plates extending from the outer periphery of the post, column or fundament towards each other thereby forming a space for the screw; at least two substantially circular washers for each screw, said washer having a diameter of at least twice the diameter of the screw; and a flange extending substantially transverse to the longitudinal axis (A), said flange comprises open recesses for accommodating the screws, wherein the guiding means are arranged on the outside periphery of the post or column and the flange is arranged on the fundament, alternatively the flange arranged on the post or column and the guiding means on the fundament, said screws are extending within said guiding means and said recesses and the flange and the guiding means clamped between the washers in order to secure the post or column to the fundament.

[0008] The claimed deformable arrangement fulfils the needs defined above by providing an arrangement that, in case of an accident, more easily releases the post or column from the fundament then previously known arrangements.

[0009] This is achieved by increasing the distance between the screws and the outer periphery of the post or column. The increased distances, in combination with the large washers that separates the screws from the post, column or the fundament and provides smooth surfaces that facilitates the slipping of the different elements of the arrangement and ensure the desired releasing of the post or column from the fundament. Furthermore the guiding means according to the invention will make it possible for the screw to be released from the guiding means via the gap between the two plates.

[0010] In one embodiment of the arrangement, the cross section of the post or column is substantially circular and the guiding means arranged at substantially equal distances from each other around the outside periphery of the post or column. Posts and columns with a circular cross section are easy to manufacture. Furthermore posts and columns with a circular cross section will have the same structural strength in all radial directions of the post or column.

[0011] In one embodiment of the arrangement, the arrangement comprises a third circular washer arranged between the flange and the guiding means. This embodiment is favourable since the additional washer will provide further support and slipping aid to the secured end of the post or column.

[0012] In one embodiment of the arrangement, said plates have a first and a second side substantially parallel to the longitudinal axis (A) and the first side of the plates is secured in the post, column or fundament.

[0013] In one embodiment of the arrangement, the second sides of the plates are positioned close to each other by not connected to each other. This embodiment improves the arrangement further since the screw within the space defined by the plats, in case of a vehicle hitting the post or column, more easily could be released from the guiding means via the gap between the plats.

[0014] In one embodiment of the arrangement, said second sides of the two plates are meeting in an angle (α) between 30° to 70°. Plates arranged in angles within this range result in guiding means that provide the desired stability to ensure that the post or column can withstand the forces from for example wind, rain and snow and the required easy breaking of the post or column since the angle between the plates will direct the screw to the gap between the plates.

[0015] In one embodiment of the arrangement, said first and second side of the plate have a length within the range of 50 ― 200 mm. Side lengths within this range provide the desired strength in the connection of the post or column to the foundation as well as the desired deformable features of the arrangement.

[0016] In one embodiment of the arrangement, said flange has a substantially flat side surface facing away from the guiding means and the flat side provides support for the washer and a screw or bolt head alternatively a nut arranged on the treads on the screw or bolt. The flat side surface makes it easier for the screws to slip out of the recesses in case of an accident.

[0017] In one embodiment of the arrangement, the recesses for the screws have a substantially circular shape large enough to house the screws and an opening larger than the diameter of the screws. The embodiment provides an arrangement that further facilitates the releasing of the screws, and consequently the post or the column, from the fundament.

[0018] Further details of the arrangement will be described in the detailed description.

Brief description of the drawings

[0019] One embodiment of the invention is illustrated in the appended figures.

Figure 1 illustrates a perspective view of the arrangement;

Figure 2 illustrates a perspective view of the guiding means arranged in the lower end of a post or column;

Figure 3 illustrates a perspective view of a flange arranged in the end of a tube-shaped section.

Detailed description of embodiments

[0020] In figure 1, a deformable arrangement 20 according to the present invention is illustrated in perspective. The arrangement 20 is used for securing for example a lamp post 10 or column to a fundament 11.

[0021] The illustrated lamp post 10 has a substantially circular cross section but the claimed arrangement could be used for all possible cross sectional shapes of posts or columns like for example triangular, rectangular as well as asymmetrical cross sectional shapes. The cross section usually comprises a peripheral wall and a hollow core but also solid poles or columns could be used.

[0022] The post 10 or column has a longitudinal axis A that mostly is vertically arranged when the post is correctly fitted to the fundament 11. The fundament, in this embodiment, comprises a tube-shaped section 12 intended to be co-axially arranged to the post or column. The tube-shaped section should be properly secured in the ground. This could for example be achieved by arranging the tube-shaped section in a excavation that are filled with concrete, alternatively by pre-casting of concrete fundaments with tube-shaped section before they are arranged in made excavations. The tube-shaped section could however be replaced by sections with other cross sectional shapes.

[0023] In the upper end of the tube-shaped section a flange 30 substantially transverse to the longitudinal axis A is arranged, illustrated for example in figure 3. The flange 30 has, in this embodiment, a substantially constant axial thickness and a triangular transverse shape. In each corner of the triangular flange 30, a recess 31 is formed. The recesses 31 have a substantially circular shape and are accessible via an opening 32.

[0024] In the end of the post or column that is intended to be secured to the fundament, three guiding means 21 are arranged, illustrated in figure 1 and 2. The guiding means 21 are arranged at substantially the same distance from each other around the outside periphery of the post 10 or column. Each guiding means consist of two substantially flat plates 22. The plates 22 are substantially rectangular with a first 23 and second 24 side arranged substantially parallel to the longitudinal axis A. For a conventional lamp post the first and second side have a length between 50 to 200 mm. Furthermore the plates should have a thickness of at least 3 mm in order to achieve the desired strength of the guiding means that is needed in order to provide a reliable securing of the post or column to the foundation.

[0025] For each plate 22, the first side 23 is secured in the post or column, for example by welding. The plates 22 of the same guiding means extend from the periphery of the post or column towards each other so that the second sides 24 are positioned close to each other. The plates 22 that are extending from the post or column towards each other thereby forms an angle α within the range of 30° to 70°. The angle α for the guiding means is dependent, for example on, the number of screws and guiding means comprised in the arrangement as well as the dimensions of the screws and washers.

[0026] In the embodiment illustrated in figure 1, the meeting second sides 24 of the plates 22 are arranged at a small distance from each other. The distance between the plates 22 could differ as long as the plates are not structurally connected and the desired guiding of the screws and the clamping of the post or column to the foundation is ensured. A larger distance between the plates 22 will reduce the desired force for releasing the post 10 from the fundament 11 since less deformation of the plates 22 are required for releasing the screws from the guiding means and the recesses. Within each guiding means, defined by the two plates, a space for a screw is defined.

[0027] In order to secure the post 10 or column to the fundament 11, the post or column is first positioned in the intended correct position. Once the post or column in correctly positioned, a screw 34 is arranged in each guiding means 21. Each screw 34 has a longitudinal axis B substantially parallel to the longitudinal axis A of the post or column. Each screw should be long enough to extend trough the guiding means 21 and the flange 30 in the end of the tub-shaped section 11. The post 10 or column is secured in the intended position by tensioning of nuts 35 in each end of the screw 34, alternatively between a screw head in one end of the screw and a nut in the opposite end of the screw, so that the flange 30 and the guiding means 21 are held tightly together. Between the screw head, or nut, and the guiding means, as well as between the screw head or nut and the flange 31, circular washers 33 are arranged. The circular washers 33 have a diameter exceeding the double diameter of the screw it is used for. In the illustrated embodiment, similar washers are also arranged between the flange and the guiding means.

[0028] In case of a vehicle hitting the post or column, the end of the post or column secured to the fundament is released from its securing in order to reduce the impact and damages on the vehicle. This is achieved by the disclosed arrangement for several reasons. First the screws, supported by the large washers could be forced out of the recesses 31 via the opening 32. The washers have, due to their size, a smooth surface that will assist in the removal of the screws from the recesses as well as the fact that the washers are free to turn around the screws and act as wheels that is assisting in the releasing of the post or column from the initial secured position. In order to further assist the releasing of the post or column from the secured position, the design of the guiding means according to the present invention will furthermore make is possible for the screw to be released from the space defined by the flat plates via the small gap between the second sides of the plates arranged close to each other.

[0029] The embodiment described above could of course be modified in many aspects and combined in all possible ways without departing from the scope of the invention that is defined by the appended claims. For example, the dimensions and numbers of many of the different components within the claimed arrangement could be amended.

Claims

1. Deformable arrangement (20) for securing an elongated post (10) or column to a fundament (11), said post or column has a longitudinal axis (A), said arrangement comprises:

- at least three screws (34) or bolts arranged around the outer periphery of the post, column or fundament, said each screw having a longitudinal axis (B) substantially parallel to the longitudinal axis (B) of the other screws and the longitudinal axis (A) of the post or column;

- guiding means (21) arranged in relation to each screw, said each guiding means consist of two substantially flat rectangular plates (22) extending from the outer periphery of the post, column or fundament towards each other thereby forming a space for the screw;

- at least two substantially circular washers (33) for each screw (34), said washer having a diameter of at least twice the diameter of the screw; and

- a flange (30) extending substantially transverse to the longitudinal axis (A), said flange comprises open recesses (31) for accommodating the screws,

wherein the guiding means (21) are arranged on the outside periphery of the post or column and the flange (30) is arranged on the fundament, alternatively the flange arranged on the post or column and the guiding means on the fundament, said screws (34) are extending within said guiding means (21) and said recesses (31) and the flange (30) and the guiding means (21) clamped between the washers (33) in order to secure the post (10) or column to the fundament (11).

2. Arrangement according to claim 1, wherein the cross section of the post (10) or column is substantially circular and the guiding means arranged at substantially equal distances from each other around the outside periphery of the post or column.

3. Arrangement according to claim 1 or 2, wherein the arrangement comprises a third circular washer (33) identical to said other two washers for each screw, said third washer is arranged between the flange and the guiding means.

4. Arrangement according to claim 1, wherein said plates (22) have a first (23) and a second (24) side substantially parallel to the longitudinal axis (A) and the first side of the plates is secured in the post, column or fundament.

5. Arrangement according to claim 4, wherein the second side (24) of the plates (22) are positioned close to each other but not connected to each other.

6. Arrangement according to claim 5, wherein said second sides (24) of the two plates (22) are meeting in an angle (α) between 30° to 70°.

7. Arrangement according to claim 4, wherein said first (23) and second (24) side have a length within the range of 50 ― 200 mm.

8. Arrangement according to anyone of the previous claims, wherein said flange (30) has a substantially flat side surface (36) facing away from the guiding means and that the flat side provides support for the washer (33) and a screw or bolt head alternatively a nut (35) arranged on the screw (34) or bolt.

9. Arrangement according to claim 8, wherein the recesses (31) for the screws (34) have a substantially circular shape large enough to house the screws and an opening (32) larger than the diameter of the screws.

Drawing