The present invention relates to an end terminal member for a guard rail .

The present invention also relates to a guard rail that comprises an end terminal member at least at one end of a rail of the guard rail .

The term "guard rail" is understood herein to mean a series of spaced-apart posts mounted to the ground and at least one lengthwise extending rail that is connected to and supported by the posts .

A major purpose of a known type of end terminal member of roadside guard rails is to absorb kinetic energy of vehicles that crash into the end terminal members . This is accomplished by the end terminal members being pushed along the rails by the vehicles and collapsing the guard rails in a way that minimises damage to the vehicles and minimises the risk of the vehicles being deflected into the paths of other vehicles on the roads .

The present invention is an alternative to currently available end terminal members that are known to the applicant.

According to the present invention there is provided an end terminal member for a guard rail , the guard rail comprising a rail that is tied directly or indirectly to the ground at a forward end of the guard rail , the rail having a main section that is at a designated height above the ground, the end terminal member having a chamber with a forward opening and a rearward opening and being adapted to be positioned at or proximate the forward end of the guard rail , and the end terminal member being formed to compress the rail in a vertical dimension of the rail and then position the compressed rail on or proximate the ground when a vehicle crashes into the member and pushes the member along the length of the rail away from the forward end of the rail until the vehicle stops .

In a situation in which the rail is tied directly to the forward end of the guard rail , the rail may comprise a forward section that is connected to the main section and is adapted to extend through the chamber to the forward end of the guard rail .

In this situation, in use of the end terminal member, the forward opening of the chamber may be on or proximate the ground and the rearward opening may be at the designated height of the main section of the rail above the ground.

In addition, in this situation, the forward opening may be formed to compress the rail to form the compressed rail, and the rearward opening may be formed to receive and guide the main section of the rail therethrough. In this arrangement, essentially all of the compressive force is applied to the rail at the forward opening of the chamber. In this context, the forward opening may be in the form of a die and the remainder of the chamber may be essentially a guide for the die . Typically, the main section of the rail has a constant transverse cross-section along the length of the main section.

Typically, the forward section of the rail is formed so that the transverse cross-section of the rail progressively changes from the transverse cross-section of the rail in the rearward opening of the chamber to the transverse cross-section of the compressed rail in the forward opening of the chamber . For example , the forward section of the rail may be progressively compressed in the vertical dimension from the rearward opening of the chamber to the forward opening of the chamber .

Alternatively, the chamber may be formed to compress the rail in the vertical dimension of the rail progressively along the length of the chamber as the vehicle pushes the member along the length of the rail . In other words, the chamber may be formed so that it applies a compressive force to the rail along the whole of the length of the chamber. Typically, this may be achieved by the chamber being formed so that there is a continuous reduction in a vertical dimension of the chamber along the length of the chamber from an inlet of the chamber to an outlet of the chamber.

The chamber may have a substantially constant width along the length of the chamber.

The end terminal member may comprise a body that defines the chamber, the body having a forward end and a rearward end, with the chamber extending through the body between the forward and the rearward ends , with the forward opening being in the forward end and the rearward opening being in the rearward end, and with the rearward opening being at a higher level than the forward opening, and with the chamber reducing in transverse cross-section from the rearward opening to the forward opening and being inclined downwardly from the rearward opening to the forward opening. In use, the end terminal member is positioned on the rail as described above, with the rearward opening being spaced above the ground and the forward opening being positioned on or proximate the ground and a forward section of the rail extending through the chamber and a main section of the rail extending horizontally away from the end terminal and supported by spaced-apart guide posts . It can be appreciated that when the body is contacted by a vehicle in a crash and pushed along the rail away from the forward end of the guard rail, the movement of the body along the rail progressively compresses the main section of the rail as the main section is progressively drawn into and through the chamber and the resultant compressed rail is repositioned to be proximate the ground.

Typically, the main section of the rail has a constant transverse cross-section along the length of the main section.

Typically, the forward section of the rail that extends through the chamber has a transverse cross-section that corresponds to the cross-section of the chamber along the length of the chamber.

In a situation in which the rail is tied indirectly to the forward end of the guard rail , the end terminal member may comprise wire ropes or the like that extend from the forward end of the guard rail through the chamber for connection to the main section of the rail , with the main section of the rail being positioned outside the chamber .

The rail may have parallel , lengthwise extending corrugations that strengthen the rail. For example, the rail may have a W-shaped cross-section. The rail may have a vertical dimension of at least 30 cm.

The rail may be formed from sheet steel .

The chamber may be formed to compress the rail into any suitable transverse profile .

For example, the chamber may be formed to compress the rail into a generally flat compact profile .

In a situation in which the rail is made from sheet steel and has parallel , lengthwise extending corrugations , the chamber may be formed to compress the corrugations together so that the rail has the generally flat compact profile .

The end terminal member may comprise a guide to guide the main section of the rail into the rearward opening of the chamber when the vehicle crashes into the member and pushes the member along the length of the rail away from the tied end until the vehicle stops .

Typically, the end terminal member is formed to withstand initial vehicle impact when the vehicle crashes into the member and subsequent pushing of the member along the rail away from the forward end of the guard rail .

The end terminal member may be formed to contact and then push over posts of the guard rail as the end terminal member is pushed along the length of the rail away from the forward end of the guard rail after the vehicle crashes into the end terminal member .

According to the present invention there is provided a guard rail that comprises (a) a rail that is tied directly or indirectly to the ground at a forward end of the guard rail, the rail having a main section that is at a designated height above the ground, and (b) an end terminal member at or proximate the forward end of the guard rail, with the end terminal member having a chamber with a forward opening and a rearward opening, and with the end terminal member being formed to compress the rail in a vertical dimension of the rail and then position the compressed rail on or proximate the ground when a vehicle crashes into the member and pushes the member along the length of the rail away from the forward end of the guard rail until the vehicle stops .

In a situation in which the rail is tied directly to the forward end of the guard rail , the rail may comprise a forward section that is connected to the main section and is adapted to extend through the chamber to the forward end of the guard rail .

In this situation, the forward opening of the chamber may be on or proximate the ground and the rearward opening may be at the designated height of the main section of the rail above the ground.

In addition, in this situation, the forward opening may be formed to compress the rail to form the compressed rail, and the rearward opening may be formed to receive and guide the main section of the rail therethrough .

Typically, the main section of the rail has a constant transverse cross-section along the length of the main section.

Typically, the forward section of the rail is formed so that the transverse cross-section of the rail progressively changes from the transverse cross-section of the rail in the rearward opening of the chamber to the transverse cross-section of the compressed rail at the forward opening of the chamber . For example , the forward section of the rail may be progressively compressed in the vertical dimension from the rearward opening of the chamber to the forward opening of the chamber .

Alternatively, the chamber may be formed to compress the rail in the vertical dimension of the rail progressively along the length of the chamber as the vehicle pushes the member along the length of the rail .

The chamber may have a substantially constant width along the length of the chamber.

The end terminal member may comprise a body that defines the chamber , the body having a forward end and a rearward end, with the chamber extending through the body between the forward and the rearward ends , with the forward opening of the chamber being in the forward end and the rearward opening of the chamber being in the rearward end, with the rearward opening being spaced above the ground and the forward opening being positioned on or proximate the ground, and with the chamber reducing in transverse cross-section from the rearward opening to the forward opening and being inclined downwardly from the rearward opening to the forward opening, whereby when the body is contacted by the vehicle in the crash the movement of the body along the rail away from the forward end of the guard rail progressively compresses and re-positions the main section of the rail to be proximate the ground.

Typically, the main section of the rail has a constant transverse cross-section along the length of the main section.

Typically, the forward section of the rail that extends through the chamber has a transverse cross-section that corresponds to the cross-section of the chamber along the length of the chamber .

In a situation in which the rail is tied indirectly to the forward end of the guard rail, the end terminal member may comprise wire ropes or the like that extend from the forward end of the guard rail through the chamber and are connected to the main section of the rail, with the main section of the rail being positioned outside the chamber. The rail may have parallel , lengthwise extending corrugations that strengthen the rail. For example, the rail may have a W-shaped cross-section. The rail may have a vertical dimension of at least 30 cm.

The rail may be formed from sheet steel .

The chamber may be formed to compress the rail into any suitable transverse profile .

For example, the chamber may be formed to compress the rail into a generally flat compact profile .

In a situation in which the rail is made from sheet steel and has parallel , lengthwise extending corrugations, the chamber may be formed to compress the corrugations together so that the rail has the generally flat compact profile .

The end terminal member may comprise a guide to guide the main section of the rail into the rearward opening of the chamber when the vehicle crashes into the member and pushes the member along the length of the rail away from the tied end until the vehicle stops .

Typically, the end terminal member is formed to withstand initial vehicle impact when the vehicle crashes into the member and subsequent pushing of the member along the rail away from the forward end of the guard rail.

The end terminal member may be formed to contact and then push over posts of the guard rail as the end terminal member is pushed along the length of the rail away from the forward end of the guard rail after the vehicle crashes into the end terminal member .

The present invention is described further by way of example with reference to the accompanying drawings , of which :

Figure 1 is a perspective view of a part of the length of an embodiment of a guard rail in accordance with the present invention, with the guard rail comprising an embodiment of an end terminal member in accordance with the present invention, and with the end terminal member shown partially cut-away to make the drawing clearer;

Figure 2 is an enlargement of the end terminal member shown in Figure 1 ;

Figure 3 is a side view of the guard rail shown in Figure 1 ;

Figure 4 is the side view of the guard rail shown in Figure 3 shortly after a vehicle has crashed into the end terminal member and pushed the member a part of the way along the length of the rail of the guard rail;

Figure 5 is a top view of the arrangement shown in Figure 4 ;

Figure 6 is a perspective view of the arrangement shown in Figures 4 and 5 from the road side, with the vehicle not shown in the drawing and the end terminal member shown partially cut-away to make the drawing clearer; and Figure 7 is a perspective view of the arrangement shown in Figures 4 and 5 from the off-road side, with the vehicle not shown in the drawing and the end terminal member shown partially cut-away to make the drawing clearer .

The guard rail shown in the Figures comprises :

(a) a series of spaced-apart posts 3 mounted to the ground;

(b) a lengthwise extending sheet steel W-shaped rail 5 with two lengthwise extending corrugations that has a vertical , i.e. height, dimension of 30-35 cm and is connected to and supported by the posts 3 above the ground and is tied to the ground at a forward end 11 of the guard rail ; and

(c) an end terminal member 7 positioned on the rail 5.

The end terminal member 7 is positioned on the rail 5 and can slide along the rail 5 when a vehicle 27 crashes into the member 7 and pushes the member 7 away from the tied end of the rail 5.

The end terminal member 7 comprises a body 31 that defines a chamber 13. The body 31 has a forward end 35 and a rearward end 37. The chamber 13 extends through the body 31 between the forward end 35 and the rearward end 37 and has a forward opening 17 and a rearward opening 19. The end terminal member 7 is positioned on the rail 5 so that the rail 5 extends through the chamber 15. The chamber 15 is formed to compress the rail in a vertical dimension of the rail and then force the rail 5 downwardly onto or proximate the ground as the member 7 is pushed along the length of the rail 5 in the direction of the arrow X by the vehicle 27, i.e. away from the tied end of the guard rail. Specifically, the chamber 15 is generally S-shaped when viewed from a side and reduces in transverse cross-section from the rearward opening 19 to the forward opening 17 and is inclined downwardly from the rearward opening 19 to the forward opening 17. In particular, the vertical dimension of the chamber 15 reduces progressively from the rearward opening 19 to the forward opening 17, while the horizontal dimension of the chamber 15 is substantially constant. This arrangement means that the chamber applies a compressive force to the rail along the whole length of the chamber 15. In other words, each part of the length of the rail is under compressive load through the whole of the length of the chamber 15. In use, the end terminal member 7 is positioned on the rail 5 as described above, with the rearward opening 19 being spaced above the ground and the forward opening 17 being positioned proximate the ground.

The rail 5 has a main rail section 9 that is at a designated height H above the ground. The main rail section 9 comprises parallel , lengthwise extending corrugations 41. In effect, the main rail section 9 is W-shaped in transverse section.

The rail 5 also has a forward section 13 that extends from a forward end 43 of the main rail section 9 and is inclined downwardly to the forward end 11 of the guard rail . The forward section 13 is tied to the ground by means of bolts 21 that extend into a mounting structure 23, such as a concrete footing positioned in the ground. The forward section 13 is formed so that it can extend through the chamber 13 in the end terminal member 7. Specifically, the forward section 13 is formed by progressively compressing a length of rail that is used for the main section 9 of the rail from one end to the other end and forming the compressed rail into an S-shape, with the tied end being completely compressed so that the rail has a flattened profile at that end.

The compression and downward displacement of the rail 5 by an advancing vehicle 27 after initial impact of the vehicle 27 with the end terminal member 7 in a crash is illustrated in Figures 3-5.

Figures 4 and 5 show the vehicle 27 after it had crashed into the end terminal member 7 and had pushed the member 7 a part of the way along the guard rail . This movement of the vehicle 27 along the guard rail forced the end terminal member 7 to slide along the main rail section 9 and thereby progressively forced the rail 5 into and through the chamber 15. In effect, the chamber 15 functioned as a die that deformed the main rail section 9 into a vertically compressed profile without significantly changing the width of the profile and then re-positioned the compressed rail 5 to be on or proximate to the ground.

The progressive compression and downward displacement of the rail 5 absorbed vehicle impact energy and thereby slowed the movement of the vehicle 27 until it stopped altogether. In addition, the re-positioning of the compressed rail on or proximate the ground minimised any damage to the vehicle 27 caused by the rail 5.

The rearward end 37 of the terminal member 7 is formed so that it pushes down rail posts 3 as the member 7 moves along the guard rail in response to the vehicle 27 crashing into the member 7 and positions to posts 3 so that they are clear of the vehicle 27 and do not damage the vehicle 27. This contact and deflection of the posts 3 absorbs further energy .

The fact that the rail 5 is tied to the ground at the forward end 11 of the guard rail and the chamber 15 is constrained to slide along the rail 5 controls the movement of the end terminal member 7 , whereby there is controlled and safe absorption of energy as the vehicle moves along the guard rail until it stops .

The materials requirements for the end terminal member 7 include requirements (a) for the chamber 15 to compress and displace the rail 5 as described above, (b) to be able to withstand impact of the vehicle 27 in the first instance and subsequent movement along the guard rail, (c) to be able to withstand contact with rail posts 3 as the end terminal member 7 is pushed along the rail 5 by the vehicle and (d) to be able to push rail posts 3 downwardly to position the posts 3 to be clear of the vehicle 27.

Many modifications may be made to the embodiment of the end terminal member 7 of the present invention and the embodiment of the guard rail shown in the Figures without departing from the spirit and scope of the invention .

By way of example , whilst the embodiment of the guard rail shown in the drawings has a single rail 5, the present invention is not so limited and extends to guard rails having two or more rails 5 at different heights above the ground.

Furthermore, whilst the chamber 13 of the embodiment of the end terminal member 7 shown in the drawings has a particular profile, the present invention is not so limited and extends to any suitable profile that can compress the rail 5 in the vertical dimension of the rail and reposition the compressed rail 5 to be proximate the ground as described above .

Furthermore, the present invention is not confined to the above-described arrangement in which the chamber 15 progressively compresses the rail 5 in the vertical dimension of the rail. The chamber 15 may be formed so that the forward opening 17 is a die that applies all of the compressive force required to form the compressed rail. In this situation, the chamber is essentially a guide for ensuring that the rail 5 is presented properly to the forward opening 17.

Furthermore, the present invention is not confined to an arrangement in which the rail 5 has a forward section 13 that is in effect threaded through the chamber 15. Instead of such a direct connection of the rail 5 to the forward end of the guard rail , there may be an indirect connection for example by means of connecting wire ropes or the like that extend from the forward end of the guard rail through the chamber 15 and are connected to the rail 5, with the rail 5 being positioned outside the chamber .