WO2010133760A1

WO2010133760A1 - Post

Info

Publication number: WO2010133760A1
Application number: PCT/FI2010/050392
Authority: WO
Inventors: Rolf JERNSTRÖM
Original assignee: Jerol Industri Ab
Priority date: 2009-05-20
Filing date: 2010-05-14
Publication date: 2010-11-25
Also published as: FI20095558A0; EP2432936A1; EP2432936A4; FI20095558L

Abstract

Post, particularly a fibre-reinforced reinforced-plastic post (1), which is formed of a hollow casing (2). In the cavity inside the casing (2) there is a belt (5), which is attache at one end in the vicinity of the lower end of the post and at the opposite end as a loop in the vicinity of the upper end of the post, with the aid of pin-like elements (3, 4) penetrating the casing of the post.

Description

Post

The present invention relates to a post, and more specifically to light, sign, or traffic-sign posts, which are widely used alongside roads.

A very usual manufacturing material for posts is a metal tube, which is either sunk directly into the ground, or placed on, for example, a post base made of concrete. A metal post is a dangerous object in a collision, in which a vehicle strikes it. This is because metal is highly inflexible relative to an impact force. If the base is sturdy, all the forces will be directed to the vehicle, while, if the post detaches from the base, it can easily form a dangerous flying object, which can kill a pedestrian, for example, if it should strike one.

Another popular manufacturing material for post is reinforced polymer resin.

Though the fibres, such as glass-fibres, used to reinforce the structure strengthen the structure in collisions as well, an impact can often cause a glass-fibre post to shatter into sharp splinters, or broken tubular pieces, which are very dangerous if they strike something. It can also happen that the post bends mainly at the point of impact, creating a bend, in which case the part above the point of impact is either thrown into the surroundings, or alternatively strikes the impacting vehicle with great force from above.

A third danger, which must be taken seriously, is that a motor vehicle breaks the post and continues at a scarcely reduced speed, but often with deficient steering, onto an adjacent cycle and pedestrian path, causing a secondary collision with those travelling on the path. Nowadays, posts are often even made to be such that permit continued movement of this kind.

A post reinforced with polymer resin, in which a ribbon-like reinforcement, with its free lower end folded inside the post and attached there, is laminated between the resin layers, is known from European patent application 02755034.2. In certain circumstances, the said type of post can also create a structure that will remain as one piece, even in a collision. However, the effects are insufficient under other circumstances.

Also known are post structures, in which a rope or similar attached at one end to the base of the post is tied to the post with a longish loop, with the intention that, in a possible collision, the entire post can detach from the base and fly farther away. Such a construction is dangerous. The flying post can seriously injure, or even kill a person nearby. A post crashing down as a totality from above can also be a serious safety risk to those in the vehicle.

Thus, the present invention is intended to create a post, by means of which serious damage to a colliding vehicle can be avoided, as can the possibility that pieces detaching from the breaking post will be a danger to others. A particularly important intention is to create a post, which, thanks to its structure, will be able to absorb the impact energy of a vehicle, so as to stop the vehicle at the point of impact, and not continue to travel, causing a secondary collision with some external object. The collision is also controlled, in such a way as to minimize injuries to the driver and passengers.

The post according to the invention can be a reinforced plastic post, or also a light-construction metal post, for example an aluminium post.

The above and other advantages and benefits of the present invention are created in the manner described as characteristic in the accompanying Claims.

In the following, the invention is described with reference to the accompanying drawings, in which

Figure 1 shows a cross-sectional schematic diagram of the post according to the invention;

Figure 2 shows an alternative embodiment;

Figure 3 shows a second alternative embodiment; and Figure 4 shows a cross-section of the same post, rotated through a right-angle relative to the direction of Figure 1.

The figures only show the part of the post that is significant in terms of describing the invention. The length of the post is, as such, of no significance in terms of the invention. The description is based on a reinforced plastic post, but, as stated above, a light-construction metal post is also a suitable basis for the invention.

The post, to which the invention can be applied, can be of even thickness from the bottom to the top, or perhaps narrowed in stages by shoulders. As such, the shape is of no significance in terms of the functionality of the invention. What is essential is that the post is hollow. Thus, Figure 1 shows a partial longitudinal section of a hollow post 1. In the post 1 , there is a casing 2, which is usually circular in cross-section and is formed from at least two layers of reinforced plastic, which is reinforced with a suitable fibre material. The mantle of the post has been designated in the drawings only with one line. It is, however, evident that the mantle has a thickness which is more than the single line.

Inside the post 1 is a strongly woven belt 5, which is attached to the post by a bolt 3 running through the post in the area of the lower end of the post, and around which the belt 5 forms a loop, which is made into a closed loop by stitching 6, by way of a suggestion. The other end of the belt 5 is attached in a corresponding manner farther up the post 1 by a corresponding bolt 4 and the loop of the belt is also closed by stitching.

The belt 5 need in no way be tight inside the post, but instead can even be quite loose. However, it is very important that the belt is not as loose as in the posts of the prior art referred to above. In other words, the looseness can rather be elasticity. The intention is in no way to allow the entire post to fly away, but instead to absorb the impact energy of the vehicle in the deformation or breaking of the post, in situ.

In the embodiment shown in Figure 2, a doubled belt 5, 5' is used. A more probable alternative to the embodiment shown is that shown in Figure 3, in which only a single loop is made from the belt 5, which runs doubled in the area between the bolts 3 and 4, but is only a loop running around the bolts.

Figure 4 shows a longitudinal cross-section in the vicinity of one end, rotated through a right-angle relative to the previous figures. The bolt 3 penetrates the walls of the post from essentially opposite sides and the belt 5 runs around it. The bolt can be of any type whatever that will remain in place, however a quite ordinary bolt, which has a head at one end and a nut screwed onto the other end, will probably serve the purpose well.

On the other hand, in terms of appearance and functionality it may be preferable for the bolts 3, 4 to be made in some other way. For example, it can be envisaged that the bolt will be of such a length that it extends more or less precisely from one outer edge of the post to the other. In that case, there will be a hole with an internal thread in the bolt, into which a screw, under the head of which a suitable lock washer is used, can be screwed from outside. In the best case, the heads of the screws will sink into the lock washers, in such a way that only the lock washer protrudes above the outer surface of the post.

In practice, the post is manufactured conventionally. As an additional operation, holes for the bolts 3 and 4 are drilled in it and the bolts are passed through the loops at the ends of the belt 5 and screwed permanently in place. The belt remains between the bolts and, in a collision, acts to ensure that parts of the post do not detach and fly into the surroundings, endangering passers-by or property, and that after the collision the vehicle does not continue on its way, causing a secondary collision.

The post is usually set in the conventional manner into a post base, which is sunk into the ground. The post base can be, and usually is of concrete and has a hole in it corresponding to the dimension of the post. Various types of adapter are used to set the post tightly into the hole of the post base.

In practical tests of the invention, a phenomenon has been observed, which plays a significant role in terms of functionality. This is because in a collision very large forces act on the transverse bolt near the lower end of the post, around which the belt runs. As a consequence, the bolt twists in the direction of the force, forming a knee outwards. As a result, at the same time the lower end of the post is crushed, pulled by the bolt which is being bent, and bulges into the opposite direction. The flattened lower end of the post forms an anchor, which prevents the post from rising out of the post base. In known solutions, the recoil of the post out of the base causes a situation, in which the colliding vehicle can continue to travel at nearly the same speed at which it struck the post.

In practical tests, it has been observed that the invention operates in the desired manner. The tests have shown that collisions taking place at normal urban-area speeds do not cause dangerous injuries to those in the vehicle, that the vehicle remains at the collision location without continuing to move, and also that the post remains surprisingly intact, without the danger of injuring others.

The tests have shown that the upper end of the post does not cause a whip-like impact to the roof of the vehicle, but that the post begins to crush starting from the point of impact with the vehicle, because the belt keeps it intact. This process absorbs the impact energy in such a way that, for example, a vehicle travelling at a speed of about 70 kph will stop at a distance of about two metres from the collision. The post crushes progressively, in such a way that in crushed portion of the post is nearly horizontal, but farther away the uncrushed portion tends to retain its nearly vertical position. The impact energy is absorbed very efficiently in this process.

One belt attachment bolt/pit is located, as stated above, in the vicinity of the lower end of the post, the other bolt, for its part, being located clearly higher in the post. However, there is no absolute location for the bolts. One example of a dimension for the distance between the bolts, and thus for the length of the belt, could be 3 - 4 metres. In the operating conditions described, this distance is sufficient to consume the impact energy of the colliding vehicle.

It is essential for both attachment points for the belt to be in the post itself. The intention is not, in the manner of the applications according to the prior art, to secure the post to the base with a long, loose rope run, while nevertheless permitting the post to rise out of the base. The intention is rather to hold the post in the base and to absorb the impact energy in it.

The material of the belt must be sufficiently strong that it will not break in a collision, but will remain to keep the post intact. A conventional plastic-based woven belt is very suitable for this purpose. The type of belt used in safety belts is a suitable example of an appropriate material, though of course the tensile strength must be greater in the belt used in the invention.

The invention can be varied in many ways, while nevertheless remaining within the scope of the protection of the inventive idea and the accompanying Claims.

Claims

1. Post, particularly a fibre-reinforced reinforced-plastic post (1) or a light-structure metal post, which is formed of a casing (2), which is hollow inside, characterized in that, in the cavity inside the casing (2) there is a belt (5), which is attached at one end in the vicinity of the lower end of the post and at the opposite end at a distance from this.

2. Post according to claim 1 , characterized in that the belt (5) is attached as a loop to the post, with the aid of pin-like elements (3, 4) penetrating the casing of the post.

3. Post according to claim 1 , characterized in that the belt (5) forms a simple closed loop, inside which the pin-like elements (3, 4) are located.

4. Post according to claim 1 , characterized in that the pin-like elements (3, 4) are bolts, in which there are threads for securing by nuts.

5. Post according to any of the above claims, characterized in that the belt (5) is attached as a loose loop inside the post.

6. Post according to any of the above claims, characterized in that the belt (5, 5') forms a loop around the pin-like elements (3, 4) and runs between them as a simple structure.

7. Post according to any of the above claims, characterized in that the belt (5) is formed of a single closed loop, which is supported at its ends by the pin-like elements (3, 4).

8. Post according to any of the above claims, characterized in that the bolt (3, 4) located at the lower end of the post is flexible and also of a type that will crush the lower end of the post.

9. Post according to any of the above claims, characterized in that the dimension of the bolts (3, 4) corresponds essentially to the outer diameter of the post and the bolts are attached in place by countersunk screws through washers.