Patent Publication Number: US-2013251453-A1

Title: Bollards, barriers and baffles formed from radial type tread

Description:
The present invention relates to the use of a reinforced rubber hoop, made from a, preferably discarded, radial tyre tread, to form an abrasion resistant, resilient, sprung bollard to dissipate kinetic energy. 
     Discarded tyres are a durable, persistent, voluminous waste product which represent a potential environmental hazard when concentrated in large quantities. Whole used tyres are used in various marine applications, as artificial reefs and as casual dock and ship fenders, where they have proved to be inert in the marine environment. By separating the tread section from the sidewalls, the volume of the discarded tyre can be reduced. This invention utilises the reinforced tread section, as a component, to form a resilient, abrasion resistant sprung bollard, displaying anisotropic properties. The bollard can be used to dissipate kinetic energy, by flexing and progressively distorting when a force is applied, once the energy has been dissipated the bollard returns to the original position. 
     Wave action represents one form of kinetic energy and is responsible for coastal erosion. Coastal erosion is mitigated by substantial structures, sea walls, groynes etc, which are expensive to construct and maintain. These structures require extensive groundwork during construction to enable them to withstand the effects of the waves by absorbing the wave energy, dissipating it throughout the structure and reflecting it away from the beach. 
     Friable shorelines consisting of soft rock, silts and shingle are also subject to erosion and while many have low economic value they have a high environmental and ecological value. The wave action is normally that of scouring silts and shingle away from the shoreline until a more resistant substrate is reached. Once the silts and shingle have been removed, the waves start undercutting the shoreline causing further collapse and repeating the cycle of erosion. 
     Other areas where a flexible sprung bollard maybe considered useful is in road signage where rigid posts present a hazard to road users in the event of an accident. 
     The present invention is thus directed to a bollard comprising a reinforced radial tyre tread and a circlip wherein the tread is folded into at least three loops and the circlip holds the central loop under compression thereby enabling the bollard to exert anisotropic properties for dissipating kinetic energy. 
     A bollard unit with anisotropic properties is created by folding the reinforced tread section, containing both the tread and carcass plies, of a disused radial ply tyre into a minimum of three loops with the central loop being compressed and held between the jaws a lateral external circlip. The lateral external circlip maybe buried in the ground leaving the two external loops in an upright position. The internal loop maybe filled with soil which prevents the loop from collapsing and pulling out from the lateral external circlip. The circlip may be fixed to the ground or other structure. 
     The present invention is considerably lighter than a conventional bollard and does not require the associated substantial groundworks. The tyre treads, containing both carcass and tread plies, are highly durable yet flexible. By extending the lateral external circlip, longitudinally, more tyre treads can be added to form a baffle or a barrier preferably for coastal defence. The patterned surface of the tyre treads dissipates the wave and reduces the resultant forces on the structure. Individual tyre tread loops progressively deform and becomes more resistant to the kinetic energy. The invention decreases erosion by trapping the littoral debris as the wave recedes. 
     The removal of the tread section reduces the bulk of waste tyre, making the remainder easier to store prior to recycling. 
    
    
     
       The present invention will now be described with reference to the following drawings of which: 
         FIG. 1  shows a side elevation of an embodiment of the present invention with symmetrical loops; 
         FIG. 2  shows a side elevation of another embodiment of the present invention with asymmetrical loops; 
         FIG. 3  shows a front elevation of an embodiment of the present invention with a longitudinally, extended external lateral circlip, and a cuff at one end for joining to another unit and an anchoring spike; and 
         FIG. 4  is a plan view of another embodiment of the present invention with the longitudinally, extended external lateral circlip and a separate collar at one end for joining to another unit and a locating hole. 
     
    
    
     The present invention relates to a bollard unit with anisotropic properties made from a reinforced rubber hoop and a lateral external circlip. The rubber hoop is prepared from a radial ply tyre by cutting the sidewalls away from the tread at the shoulder of the tyre. Some of the carcass plies are cut but the tread plies remain encapsulated within the rubber. 
     The tyre tread hoop is folded into a minimum of three loops labelled A, B and C as shown in  FIGS. 1 and 2 . Loops A and C are formed by a single thickness of tread.  FIG. 1  illustrates loops A and C being symmetrical whereas  FIG. 2  illustrates loops A and C being asymmetrical. 
     As shown in both  FIGS. 1 and 2 , loops A and C are held upright to the external circlip, D, by confining loop B in the external circlip. Loop B is formed by a double thickness of tread, compressed and held within the lateral external circlip. The lateral external circlip is longer than the width of the tyre tread. The external diameter of loop B, is greater than the distance between the jaws of the lateral external circlip. The distance between the jaws of the external circlip is less than the internal diameter of the external circlip. The external circlip maybe made of a polymeric or metallic material or a combination of both. 
     When deployed, loop B and interstices between loop B and the walls of the external circlip are filled by the surrounding soil to the natural ground level. 
     Bollards, barriers and baffles maybe constructed using the same methodology, as described above, by longitudinally extending the external circlip and the addition of more folded tyre hoops. The rubber hoops/loops are placed at intervals along the length of the external circlip. 
     As shown in  FIG. 3 , an integrated cuff, E, disposed at one end of the external circlip allows extended barrier units to be slotted together. Alternatively as shown in  FIG. 4 , the extended barrier units maybe joined by the use of a separate sleeve or collar, G. 
     In use, the bollard or barrier maybe located within a trench (not shown). Filling the location trench maintains the disposition of the bollard or barrier and the distance between upright tyre treads. In addition or alternatively, soil or other medium may be placed within loop B to act as a locking mechanism. Finally, holes, H, maybe drilled at intervals, in the external circlip, to allow for an anchoring spike, F, or screw or bolt to pass through to fix the barrier unit and/or prevent the rotation of the extended units. 
     The present invention has been described and illustrated but it will be envisaged that modifications may be made but within the remit of the claims as hereinafter defined.