Impact device

Abstract

Described herein is an impact device that may be slidably coupled to a wire rope barrier terminal end and, in the event of an impact on or about the terminal end by a vehicle, the impact device is configured to slide or advance along the terminal end wire rope(s) towards a wire rope barrier end and away from a terminal end anchor position. In a further embodiment, a method is described of retrofitting existing wire-rope barrier terminal ends with the device. The impact device may simultaneously (at least to some extent) absorb kinetic energy from the impact as well as redirect the direction of impact along the terminal end wire rope(s) towards, and optionally along, the wire rope barrier itself depending on the extent of impact. The sliding action also knocks over any posts in the direction of errant vehicle travel in an impact.

1 . An impact device comprising:
 a contact element configured to contact and optionally engage an errant vehicle in a collision event,   a guide member configured to receive and retain at least one wire rope from a wire rope barrier or wire rope barrier terminal end about or therein, and,   in the event of an impact, the impact device slidingly engages the at least one wire rope about or therein the guide member and wherein the at least one wire rope is directed about or through the contact element during sliding of the impact device along the at least one barrier wire rope.   
     
     
         2 . The impact device as claimed in  claim 1  wherein the guide member is elongated and 5-20 times longer than the guide member height or width. 
     
     
         3 . The impact device as claimed in  claim 1  wherein the guide member is configured to have a length that takes up 25% or more of the length of need (LON) of a wire rope barrier terminal end. 
     
     
         4 . The impact device as claimed in  claim 1 , wherein the impact device is configured to gather and direct movement of all of wire ropes of the wire rope barrier during sliding travel of the impact device. 
     
     
         5 . The impact device as claimed in  claim 1 , wherein the impact device is configured to be fitted to the wire rope with friction and without need for fasteners, with the guide member holding the impact device in place relative to the wire rope. 
     
     
         6 . The impact device as claimed in  claim 1  wherein the contact element comprises an impact plate with projections on the contact element configured to engage an errant vehicle impacting the impact device. 
     
     
         7 . The impact device as claimed in  claim 1 , wherein the contact element includes rounded sides extending from the contact element configured to extend the impact region on the impact device contact element. 
     
     
         8 . The impact device as claimed in  claim 1 , wherein the contact element has weakened areas that break or deform when a reverse impact occurs. 
     
     
         9 . The impact device as claimed in  claim 1 , wherein the contact element is configured to mechanically deform in the event of an impact. 
     
     
         10 . The impact device as claimed in  claim 1 , wherein the contact element comprises an opening and wherein the opening provides a passage leading to the guide member through which wire rope is threaded. 
     
     
         11 . The impact device as claimed in  claim 1 , wherein the at least one wire rope is directed under or over the contact element. 
     
     
         12 . The impact device as claimed in  claim 1 , wherein the guide member is an elongated channel or pair of brackets configured to gather and direct movement of wire rope therein during sliding travel of the impact device. 
     
     
         13 . The impact device as claimed in  claim 12  wherein the elongated channel or pair of brackets include obstruction members to obstruct wire rope exit from the channel or pair of brackets and, wherein the obstruction members do not impinge on the wire rope in the guide member. 
     
     
         14 . The impact device as claimed in  claim 1 , wherein the guide member internal shape is varied to alter the sliding friction on the wire ropes. 
     
     
         15 . The impact device as claimed in  claim 1  wherein the impact device comprises a base configured as legs, rails or at least one shaped projection, the base or a part thereof contacting-the ground beneath the impact device post install and/or during an impact and subsequent sliding movement. 
     
     
         16 . A terminal end of a wire rope barrier comprising:
 at least one wire rope extending from the wire rope barrier to the terminal end;   at least one post and at least one anchor point for the at least one wire rope;   the terminal end configured to gather and direct the at least one wire rope from the wire rope barrier position with the wire rope elevated above a ground surface to an anchored position about or on ground surface; and   an impact device as claimed in  claim 1 .   
     
     
         17 . The terminal end as claimed in  claim 16  wherein the terminal end of the wire rope barrier comprises 3 to 4 wire ropes. 
     
     
         18 . The terminal end as claimed in  claim 17  wherein the wire ropes flare about a horizontal plane from the contact element to the ground anchor points. 
     
     
         19 . A wire rope barrier comprising wire rope, terminal ends and at least one impact device, wherein:
 the wire rope barrier comprises at least one wire rope located generally parallel to a roadway and held above road surface via a series of posts;   terminal ends of at least one wire rope, at least one post and at least one anchor point for the at least one wire rope, the terminal ends being configured to gather and direct at least one wire rope from a barrier position with the wire rope elevated above a ground surface to an anchored position about or on the ground surface; and   mounted on or about one or both terminal ends, the at least one impact device as claimed in  claim 1 ; and   wherein, once impacted, the impact device is configured to be pushed, via sliding action, downstream along the wire rope of the terminal end and wire rope barrier itself, the impact device gathering and directing movement of the wire rope barrier wire rope during sliding travel of the impact device.   
     
     
         20 . The wire rope barrier as claimed in  claim 19  wherein, as the impact device slides, the impact device is configured to deform wire rope barrier posts, clearing the posts out of the way of the impact device during sliding movement. 
     
     
         21 . The wire rope barrier as claimed in  claim 19  wherein, as the impact device slides, the impact device removes the wire rope barrier wire cables from their post connection. 
     
     
         22 . The wire rope barrier as claimed in  claim 19  wherein the terminal end of the wire rope barrier comprises 3 to 4 wire ropes. 
     
     
         23 . A method of absorbing and directing the energy associated with an impact on or about a wire rope barrier terminal end by a vehicle, comprising the steps of:
 providing a wire rope barrier as claimed in  claim 19 ; and   in the event of an impact by a vehicle to the wire rope barrier terminal end, the impact is at least partly received by the impact device and, on impact, the impact device slides along the at least one wire rope.   
     
     
         24 . The method as claimed in  claim 23  wherein the action of sliding at least partly absorbs kinetic energy and at least to some extent, redirects the direction of impact force to coincide with the direction of movement of the impact device along the wire rope. 
     
     
         25 . The method as claimed in  23  wherein the action of the impact device sliding acts to knock over posts as the impact device advances along the wire rope.