Patent Publication Number: US-8973903-B2

Title: Bendable pole for wire-rope safety fences

Description:
FIELD OF THE INVENTION 
     The present invention concerns a bendable pole for wire-rope safety fences, in accordance with the claims. 
     TECHNICAL BACKGROUND AND PRIOR ART 
     Today, wire-rope safety fences, which are usually located between traffic lanes, are used to separate traffic traveling in opposite directions which keeps vehicles from colliding with each other. The wire-rope safety fence prevents oncoming traffic from crossing over into their opposite lanes and thus prevents vehicles from colliding with each other. Wire-rope safety fences are also used as shoulder side wire rope, placed at the road&#39;s shoulder to prevent traffic from running of the roadway. 
     Wire-rope safety fences use poles to hold up and fixate the wire-rope safety fence in relation to the roadway. Today&#39;s wire poles have major drawbacks. First, the wire poles have such stability in the vehicle&#39;s direction of travel that major injury occurs, especially in connection with the collision of vehicles such as motorcycles. Secondly, existing poles (profile wire beam) include their upper part of grooves which are intended to fix the wires in the horizontal direction which helps to aggravate the injury for a motorcyclist who runs into the wire poles of a wire-rope. 
     Today&#39;s wire-rope is not suitable for collision with motorcycles. In a collision between a motorcyclist and a wire-rope safety fence the motorcyclist usually receive serious bodily harm. It is not uncommon for today&#39;s wire poles to cause so great bodily harm that not even a first-aid relief effort will be able to prevent the heavy bleeding caused by a collision with current existing wire poles. 
     A further problem with existing wire poles is that they also cause great material damage, which means high repair costs. Today&#39;s wire poles cause in certain situations such great damage to vehicles such as cars that they must be scrapped and taken out of service, which results in subsequently high costs for individuals and insurance companies. 
     A yet further problem with existing wire poles is that their construction means that they are largely destroyed (becomes unusable) after a collision and must be replaced with new poles. The consequence of replacing the poles is high material and labor costs. In addition to this there is always great risk of injury for roadwork personnel during these repairs that have to be carried out in traffic, where motorists often do not respect the reduced speed limits. 
     BRIEF DESCRIPTION OF THE CONCEPT OF THE INVENTION 
     The main purpose of the present invention is to significantly reduce the above mentioned disadvantages and drawbacks. Another purpose of the present patent application is to provide a device which preferably is more cost effective to install and maintain than previously known designs. These purposes are achieved with the aid of a design in accordance with the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following detailed description of the present invention, reference and references to the following figures will occur. These figures are briefly described in the following figure list. The figures in the exemplified embodiment are not limiting for the scope of protection of the present patent application. Note that the figures are schematic and that certain details thus can be omitted. 
         FIG. 1  shows a front view of the first embodiment of the present wire pole. 
         FIG. 2  shows a side view of the first embodiment of the present wire pole. 
         FIG. 3  shows a cross section of the wire pole in accordance with section III of  FIG. 1 . 
         FIG. 4  shows a cross section of the wire pole, with an associated foot section, according to section IV of  FIG. 1 . 
         FIG. 5  shows a cross section of an alternative embodiment of the wire pole with several pole sections. 
         FIG. 6  shows a cross section of the wire pole according to section V of  FIG. 1 . 
         FIG. 7  shows an alternative embodiment of the wire pole where it is wider in its lower part than in its upper part. 
         FIG. 8  shows an exemplifying embodiment of a spacer unit in a front elevational view. 
         FIG. 8A  shows the exemplifying embodiment of a spacer unit in a top view. 
         FIG. 8B  shows the exemplifying embodiment of a spacer unit in a side elevational view. 
         FIG. 8C  shows the exemplifying embodiment of a spacer unit in a rear elevational view. 
         FIG. 9  shows a side view of a wire-rope safety fence. 
         FIG. 10  shows a wire-rope safety fence seen from above. 
         FIG. 11  shows a wire-rope safety fence seen from above. 
         FIG. 12  shows a pole as seen from above, somewhat enlarged and angled. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the figures, a bendable wire pole  1  in accordance with the present patent application is shown. The unique feature of the present wire pole  1  is that it is bendable in the direction of travel but at the same time also has good lateral and horizontal stability. 
     The bendable wire pole  1  includes at least two or more elongated curved-shaped pole sections  2  with at least one intermediate pole section  3 . The elongated curved-shaped pole sections  2  form at least one interior cavity (compartment, space)  4   
     The intermediate pole section  3  is preferably of a flat design. The pole sections  2  and  3  have essentially the same width. The first elongated curved-shaped pole section&#39;s  2  and the intermediate pole section&#39;s  3  side edges coincide with each other. 
     All sections  2  and  3  are in their upper part equipped with a groove (slot)  5  in the sections&#39; longitudinal direction in which steel wires are designed to be inserted from above during their assembly. The wires are fixed and positioned in the groove  5  with at least one spacer unit  6 . The spacer unit  6  is preferably made of thin spring steel or a material with similar properties. The spacer unit  6  is preferably equipped with a number of holes  7 , which corresponds to the number of wires in the wire-rope safety fence. The spacer unit  6  further includes a number of slits (grooves)  8  from the holes  7  to the edge of the spacer unit  6 . The spacer unit  6  is preferably equipped with as many slots as the number of holes  7 . The slots have a width (dimension), preferably smaller than the diameter of holes, so that the wires are locked and secured in a vertical position on the pole&#39;s slot. 
     During assembly of the pole  1  the cables (wires) are mounted from the top of the groove  5  in the pole  1 , then the spacer unit  6  is inserted from the side, between the pole sections  2  and this locks the wires in the vertical position. Alternatively, the spacer unit  6  is attached to the wires before the wires and the spacer unit  6  are inserted from the top of the groove  5 . The distance unit  6  is preferably slightly curved and is above the poles upper end preferably equipped with reflective material and also functions as a warning device. The spacer unit  6  is in its upper end extended (has a part which in use is visible above the pole&#39;s top end). The extended portion is preferably provided with reflective material  9  on both sides. 
     Preferably the pole  1  in its lower part includes at least a foot section  10  with which the pole, is intended to be connected to the roadway or the like. Foot section  10  is in its upper part intended to be inserted into a cavity  4  between the pole sections  2  in the bottom of the pole  1 . The intermediate section  3  is connected to the foot section through a slit as shown in cross section IV-IV in  FIG. 4 . Foot section  10  is also a profile which is consistent with the external pole sections&#39;  2  profiles and connects sections  2  and  3 . Sections  2  and  3  are mounted in the foot section  10  with through rivets  11  or screws or the like and are then enclosed when needed by an appropriate cohesion body. Foot section  10  may alternatively be of molded plastic or the like formed into the desired shape and join sections  2  and  3  into one unit, thereby simplifying the manufacturing process. 
     The spacer unit  6  is preferably used as a combined reflective and spacer device that can advantageously be white in its base color or another for the purpose of appropriate color. 
     Alternatively, the pole or spacer unit may be enclosed by a cohesion body  12  which is white in color and that reflective materials is then mounted on the outside of the cohesion body, preferably on both sides as shown in  FIG. 8 . 
     The first and last pole  1  in a stretch of wire-rope safety fence, such as shown in  FIGS. 7 and 9  is exposed to a higher load than the other poles. The higher load is dependent on that the wires are attached to the road surface and are angled up to the pole resulting in a higher load on the first and last post in a stretch of wire-rope. The first pole and the last pole  1  in a length of wire-rope are thus preferably reinforced. This reinforcement could for example be achieved by the pole being designed in a thicker material. Alternatively, the first and last pole can be reinforced by several curved sections the pole&#39;s lower part. 
     In an alternative embodiment, shown in  FIG. 7 , the pole in its longitudinal direction has a conical (tapered) shape. The conical (tapered) wire pole makes the pole more stable in the lower part, while retaining its flexible features at the top. The tapered pole makes it particularly suitable for use as a warning marker in conjunction with the wire-rope safety fence beginning and ending. Starting and ending a stretch of wire-rope with a conical wire pole also has the advantage that it better withstand the increased forces that occur when the wires goes from the anchor points in the roadway to a higher horizontal position secured in the pole. 
     With reference to  FIG. 10  is shown how the wire poles of a wire-rope safety fence can be placed perpendicular in relation to the roadway&#39;s direction of travel. 
     With reference to  FIG. 11  is shown how the poles of a wire-rope safety fence can be placed angled relative to the direction of travel. The angle of the poles leads to further reductions in injuries during collision with the poles. 
     The pole&#39;s lateral stability is reinforced by one or more thin flat sections  3  placed between the curved sections  2 . The new wire pole retains by a combination of curved sections and one or more flat sections, a lateral stability that together prevents traffic from crossing over to the oncoming traffic lane. 
     The new wire pole can be used both as a wire pole in a wire-rope safety fence separating traffic lanes and as wire-rope safety fences at the shoulders (edges) of the road. The design results in a reduced risk of injury for motorcyclists colliding with wire-rope safety fences. 
     In the detailed description of the present invention, design details may have been omitted which are apparent to persons skilled in the art. Such obvious design details are included to the extent necessary so that the proper and full performance of the present invention is achieved. 
     Even if certain preferred embodiments have been described in detail, variations and modifications within the scope of the invention can become apparent for specialists in the field and all such are regarded as falling within the scope of the following claims. 
     Advantages of the Invention 
     The present invention achieves a number of advantages. First, the pole reduces injuries to a large extent for a motorcyclist that collides with the wire pole. A further advantage of the present wire pole is that it causes less damage to vehicles driving on the pole than previously known designs of wire poles. The present wire pole also has the advantage that it includes fewer parts. For example, the pole includes parts that have multiple functions in a single detail. Furthermore, the need for fasteners such as clamps, spacers, and more is reduced. It is also an advantage of the present wire pole that the same design can be used for both middle and side wire-rope fences. A still further advantage of the present wire pole is that its flexibility will reduce the need for costly and dangerous maintenance work since the poles thanks to their spring-like properties are not susceptible to breaking to the same extent as current designs.