Metal Roadway Safety Barrier

Abstract

Metal roadway safety barrier formed by a series of horizontal rails, girders or fences ( 1 ) mounted on vertical posts ( 2 ) by means of a “breakable” joining mechanism ( 3 ) which provides said joint with the possibility of disengaging in a controlled manner when the level of the force transmitted thereto, following the impact of a vehicle, reaches a given value. The “breakable” joint is formed by a screw ( 3 ) which has along its shank, at a certain distance from its head, a cross-section of lesser mechanical strength. In an alternative embodiment, the “breakable” joint is formed by means of a “breakable” washer.

1 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, characterized in that some of the components comprising the bolted joints ( 3 ) connecting the fence ( 1 ) to the pole ( 2 ) has, at least, one characteristic that confers said joint ( 3 ) a controlled fusible behavior when impacted by a colliding vehicle, which enables it to be uncoupled or released when the level of the force transmitted to said joint ( 3 ) by the vehicle impacting the barrier reaches a pre-established value. 
     
     
         2 . Bolted joint mechanism placed between the horizontal fence and vertical is support poles of metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claim 1 , characterized in that the bolt ( 5 ), the bolted joints ( 3 ) between the fence ( 1 ), and the pole ( 2 ) present, in the rod ( 10 ) and at a given distance from the bolt's head ( 9 ), a section or area ( 11 ) having lower mechanical resistance than the remaining bolt's rod ( 10 ). 
     
     
         3 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claim 2 , characterized in that the section or area ( 11 ) having lower mechanical resistance has been obtained by applying a mechanical, thermal or chemical treatment to that particular section o area ( 11 ) of a bolt ( 5 ) that before said mechanical, thermal or chemical treatment presented the same mechanical resistance along its entire rod. 
     
     
         4 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claims 1 ,  2  and  3 , characterized in that the rod ( 10 ) of the bolt ( 5 ) comprising and the bolted joints ( 3 ) between the fence ( 1 ) and the pole ( 2 ) has, at a given distance from the bolt's head ( 9 ), a furrow-like section or area ( 12 ), preferably cylindrical, which diameter is smaller than the diameter of the rod ( 10 ). 
     
     
         5 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claims 1 ,  2  and  3 , characterized in that the rod ( 10 ) of the bolt ( 5 ) comprising the bolted joint ( 3 ) between the fence ( 1 ) and the pole ( 2 ) have at a given distance from the bolt's head ( 9 ), one or several notches ( 12 ′) that are perpendicular to the rod's ( 10 ) shaft, or slightly tilted from the perpendicular axis of the rod ( 10 ), all of said notches ( 12 ′) preferably located in the same straight section of said rod ( 10 ). 
     
     
         6 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claim 5 , characterized in that the notches ( 12 ′) made in the rod ( 10 ), that are perpendicular to the rod's ( 10 ) shaft, or slightly tilted from the perpendicular axis of the rod ( 10 ), are all located in two or more different straight sections of the rod that are preferably closely set together. 
     
     
         7 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claims 1 ,  2  and  3 , characterized in that the rod ( 10 ) of the bolt ( 5 ) comprising the bolted joints ( 3 ) between the fence ( 1 ) and the pole ( 2 ) has, at a given distance from the bolt's head ( 9 ), one o several grooves ( 12 ″) which axis are perpendicular to the rod's ( 10 ) shaft or slightly tilted from it, and all said notches ( 12 ″) preferably located in the same straight section of said rod ( 10 ). 
     
     
         8 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claim 7 , characterized in that the grooves ( 12 ″) made in the rod ( 10 ), are perpendicular to the rod's ( 10 ) shaft or slightly tilted from it, and are located in two or more different straight sections that are, preferably, set close together. 
     
     
         9 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that the sections or areas ( 11 ) ( 12 ) ( 12 ′) ( 12 ″) of the bolt's rod ( 10 ), of the bolt ( 5 ) comprising the bolted joint ( 3 ) between the fence ( 1 ) and the pole ( 2 ) having lower mechanical resistance are located along the bolt's rod ( 10 ) and at a given distance from the bolt's head ( 9 ), in a position such that, once the bolted joint ( 3 ) is implemented, the sections or areas having lower mechanical resistance ( 11 ) ( 12 ) ( 12 ′) ( 12 ″) are then located, simultaneously, inside both the orifice ( 13 ) of the fence ( 1 ) and the orifice ( 14 ) of the pole ( 2 ), both orifices ( 13 ) and ( 14 ) being part of said joint ( 3 ), so that the mechanical rupture of the rod ( 10 ), caused by the forces, transmitted to the bolted joints ( 3 ) between fence ( 1 ) and pole ( 2 ) after a vehicle collides against is the metallic barrier tends to occur in the sections or areas ( 11 ) ( 12 ) ( 12 ′) ( 12 ″) of the rod having lower mechanical resistance. 
     
     
         10 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that the bolted joint ( 3 ) between fence ( 1 ) and pole ( 2 ) incorporates a flat washer ( 6 ), preferably rectangularly shaped, located just underneath the bolt's head ( 9 ) and above the fence ( 1 ). 
     
     
         11 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that the bolted joint ( 3 ) between fence ( 1 ) and pole ( 2 ) incorporates a flat washer ( 7 ), preferably square, rectangular or round, located just underneath the locking nut ( 8 ) and above the pole ( 2 ). 
     
     
         12 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle, lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that said joint ( 3 ) is used in a metallic safety barrier solely comprising a continuous horizontal fence ( 1 ) supported by a series of vertical poles ( 2 ), aligned at regular intervals and inserted in the terrain ( 4 ). 
     
     
         13 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that said joint ( 3 ) is used in a metallic safety barrier comprised by a continuous horizontal fence ( 1 ) supported by a series of vertical poles ( 2 ), aligned at regular intervals and inserted in the terrain ( 4 ) and one or several rear braces ( 25 ) attached ( 26 ) (sic) to the poles ( 2 ) 
     
     
         14 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that said joint ( 3 ) is used in a metallic safety barrier comprised by two continuous and symmetrical horizontal fences ( 1 ) supported by a series of vertical poles ( 2 ), aligned at regular intervals and inserted in the terrain ( 4 ), both fences ( 1 ) installed symmetrically on each side of the pole ( 2 ). 
     
     
         15 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to the previous claims, characterized in that the barrier incorporates a small-sized intermediate part ( 15 ) installed between the fence ( 1 ) and the pole ( 2 ), wherein the fusible bolted joint ( 3 ′) may be installed either between the fence ( 1 ) and the intermediate part ( 15 ), or the fusible bolted joint ( 3 ″) maybe installed between the intermediate part ( 15 ) and the pole ( 2 ) or at both joints ( 3 ′) and ( 3 ″). 
     
     
         16 . Bolted joint mechanism placed between the horizontal fence and vertical support poles of a metallic safety barrier intended to contain vehicle lateral impacts at the margins and median strips of roads, according to  claim 1 , characterized in that the bolted joint located between the fence ( 1 ) and the pole ( 2 ) incorporates a fusible washer ( 18 ), having, preferably, a “U” shaped section, located underneath the head of bolt ( 5 ) of the joint, and above the fence ( 1 ), that can be fully pierced by the head of the bolt ( 5 ) when the force applied to the joint caused by the impacting vehicle exceeds a given value, triggering the mechanism that uncouples or disengages the joint connecting fence ( 1 ) to pole ( 2 ).