VEHICLE CRASH PROTECTION DEVICE

Abstract: A vehicle crash protection device suitable for instance for placement alongside roads, is described which comprises a cover surrounding a shock absorbing granulated material comprising rubber and resilient plastics.

Description: VEHICLE CRASH PROTECTION DEVICE This invention relates to a vehicle crash protection device suitable, for example, for placement alongside roads, between opposing driving lanes, in front of hazardous spots such as highway exit ramps, bridge abutments and guard-rails, around motor racing courses and at dangerous spots during rally competitions. The vehicle crash protection device is intended to provide good protection both for vehicle drivers and passengers as well as for people located behind said device in the event of a lighter vehicle, such as a car, crashing into it. A common predominant crash barrier device used in front of fixed obstructions, such as highway exit ramps, bridge abutments and support columns, is a container filled with sand or a container filled with sand and leca-balls. Such crash protection devices according to previous technology are, for example, described in U.S. Patent No. 3,606,258, 4,073,482, the British Patent No. 2,060,036 and the Swedish Patent 444 829. The drawbacks with containers filled with sand as described in the three first mentioned references are related to the fact that sand is a rigid material which does not provide a sufficiently soft impact absorber. The crash protection modules filled with leca-balls have the disadvantage that leca-balls also comprise a somewhat rigid material and this is destroyed in a collision. Furthermore, such crash modules filled with leca-balls have proven to be too expensive to compete with the sandfilled containers. Around motor racing tracks, hay-bales and rubber tires, for example, are used as crash barrier modules. Hay-bales are too light to stop a vehicle effectively, while tires stapled on top of each other have too little weight and too high elasticity to ensure good protection. These characteristics constitute clear disadvantages when the purpose of the crash protection device is to protect people behind the crash barrier modules. One frequently occurring problem with prior crash protection devices is that the colliding vehicle has a tendency to "climb up" onto the device. As a result of this ramp effect the vehicle can overturn. The crash protection module according to this invention consists of a cover, e.g. in the form of a bag, which contains a shock absorbing granulated material of rubber, elastic plastic material or mixtures thereof. The cover of the crash protection device is made of a tough, wear and weather resistant elastic material. A suitable material is, for example, a fabric of polypropylene. The shape of the cover can be varied according to the use and location of the crash protection device. The crash protection module can, for example, take the form of bale-like bags having circular, conical or rectangular shape. The crash protection module may also be shaped for wrapping rail guards, sign posts and other obstacles whereupon the wrapped element will function as a reinforcement or armament of the crash protection device. Furthermore, when the cover has the shape of a sack, these sacks can be provided with interconnecting devices such as, for example, strong bands of e.g. polypropylene, polyester, polyamide and similar materials, thus providing means to link together several bags or to secure the bags to fixtures in the ground thus providing a crash barrier. The exterior of the cover may of course be equipped with reflecting material, among other things, if desired, to give warning signals and/or information. The design of the cover can be tailored for special uses. Crash protection modules intended for temporary installation, for example for the protection of personnel occupied with repair work or the like on the road, can suitably be provided with straps and eyelets to facilitate lifting of the modules when being placed on the site or when being taken away. One example of a typical construction of a crash protection device consisting of several bags interlinked to form a crash barrier is shown in fig. 1. The bags, each with a volume of ca 1 cubic meter and containing the shock absorbing material, are equipped with an outer cover made of the same woven fabric. The outer cover is put over the sack and has bands fastened to it, which enable interconnection with other bags. Straps fixed to the inner cover pass through holes in the outer cover so that the whole bag can be easily lifted. The design of the bag is such, and especially when it is covered by an outer cover, that it will only brake in a very violent vehicle crash. The granulate is so soft that grains flying out of the bag in such a case will not cause damage. The granulate is easy to gather up, with a vacuum cleaner, for example, and transfer to a new bag. The shock absorbing granulated material consists of rubber and/or plastics. Suitable raw materials for the shock absorbing granulate are plastics and rubber recycled from car scrap and cable scrap. For the purpose of this invention such recycled material is minced to a particle size of 1-30 mm and preferably 3-20 mm. whereby the plastic material usually is granulated to a smaller particle size than the rubber material. The shock absorbing material can consist of plastic material only, rubber material only or a mixture of both. The hardness of the rubber and/or plastic materials to be used as shock absorbing material according to this invention shall be between 40 and 95 Shore A. The bulk density of the shock absorbing material is in the range of 0.3 to 0.7 tonne/cubic metre. Suitable plastics for use as the shock absorbing material according to this invention are plasticized PVC, polyethylene, crosslinked polyethylene and polyurethanes and mixtures of said polymers. The rubber material consists preferably of recycled rubber from hoses, membranes, fittings and other parts from cars, for example, and other kinds of scrap containing rubber or similar production scrap coming from rubber factories. The crash protection module when it has the form of a bag, contains an amount of shock absorbing material of preferably between 0.6 and 2 cubic metres. In an alternative embodiment to make the content of the bag heavier and thus better anchored to the ground if so desired,, the bottom part of the bag can be filled with a heavier material having a bulk density above 1.5 ton/cubic metre, e.g. sand, clay, concrete, gypsum, barium sulphate and others. The heavy material, the purpose of which is to increase the frictional force of the bag against the surface can be filled up to a height of between 5 and 25 cm from the bottom of the bag. In order to provide very good protection against a head-on crash with an ordinary car the crash protection module according to this invention when used in the form of a separate bag, shall have a diameter of about 1 m and contain about 600kg (400 to 800 kg) shock absorbing granulate consisting of rubber and/or resilient plastics. When a colliding vehicle, for example an ordinary sedan car, hits the bag, the bag will yield and take the shape of the front of the vehicle. In this way the retardation forces are distributed over a large surface and the impact absorbed. The shock absorbing material in the bag together with the enclosed air will be compressed and absorb the force of the impact by the plastic and elastic deformation. The bag folds itself around the front of the vehicle whereby the tendency of the car to "climb over" the crash barrier is prevented. By placing several bags in front of each other the retardation force in a collision can be significantly reduced when, for example, an ordinary car collides with a fixed obstacle. When the crash protection device according to this invention is used as a freely standing crash barrier to, for example, protect road workers, it is suitable to link together two or more bags and optionally anchor end bags to fixtures in the ground with appropriate methods. When a vehicle crashes into the rather soft bag, the bottom part of the bag will press against the surface, e.g. the surface of the road, the friction force will increase and the distance the vehicle will push the bag will decrease. When several bags are connected to a barrier and placed at a road construction site or around a motor racing course, for example, the energy of the crashing vehicle is distributed even more when the bag hit in the collision is forced backwards and drags the surrounding bags as well. The invention is further illustrated by the following examples. Example 1 A crash test was carried out on an official testing track of a fixed obstacle with collision protection consisting of square-shaped bags having a side wall of about 1 m and a weight of about 700 kg containing shock absorbing rubber granulate. The bags had two covers of polypropylene fabric and the outer cover had bands fastened to the fabric for interconnection. Three of these bags were linked together in one row and placed in front of the fixed obstacle, a concrete block. Another two bags were joined together and placed in a row just in front of the first row of bags. The bags were hit head-on by an ordinary sedan car, a Saab 99, at a speed of 70 km/h. The G-force of the retardation measured at the crash compared to a crash without any crash protection device decreased from at least 30 G to about 13 G. At the same time the stopping distance of the car increased from 0.5 m to about 1.5. m. Example 2 A crash test was carried out on an official testing track of a freely standing protection barrier of the same bags as used in example 1. In this test the first row with three interlinked bags was placed 1 m from and in front of the concrete block and the row with the two bags was placed in front of the first row and 3 m away from the concrete block. The row with two bags was hit by an ordinary sedan car, a Saab 99, at a speed of 70 km/h. The average G-force measured at the crash was about 10 G and the stopping distance about 3 m. The result shows that the driver of a car, wearing a safety belt, has very good prospects of avoiding injury in such a collision.

Claims: CLAIMS 1. A crash protection device characterized in that it comprises a cover surrounding a shock absorbing granulated material of plastic and/or rubber. 2. A crash protection device according to claim 1 characterized in that the shock absorbing material consists of granulated plastic and/or rubber material recycled from car and cable scrap. 3. A crash protection device according to claims 1 and 2, characterized in that the shock absorbing material has a particle size of 1 to 30 mm and a hardness of 40-95 Shore A. 4. A crash protection device according to any of the foregoing claims, characterized in that the bulk density of shock absorbing material lies in the range of 0.3 - 0.7 tonne/ cubic metre. 5. A crash protection device according to any of the fore¬ going claims, characterized in that the plastic in the shock absorbing granulated material is selected among plasticized PVC, polyethylene, crosslinked polyethylene and polyurethanes and mixtures of these plastics. 6. A crash protection device according to any of the foregoing claims, characterized in that it is in the form of a bag having a volume of from 0.6 to 3 cubic metre containing the shock absorbing material. ) 7. A crash protection device according to any of the J foregoing claims characterized in that said crash protection device is in the form of one or more bags provided with interconnecting means in the form of bands whereby several bags may be connected to one another or to fixtures in the ground to constitute a protection barrier. 8. A crash protection device according to any of the foregoing claims, characterized in that the cover surrounding the shock absorbing material in its turn is surrounded by further cover on which connection means in the form of bands are fastened and this outer cover is put on top of the inner cover to reinforce the construction of the device and prevent leakage of shock absorbing material at a vehicle crash. 9. A crash protection device according to any of the foregoing claims, characterized in that the cover material consists of polypropylene. 10. A crash protection device according to any of the foregoing claims characterized in that the bottom part of the bag is filled with a heavy material having a bulk density not ess than 1.5 tonne/cubic metre.

Inventors: LARSSON LARS-HUGO, MAARTENSSON BENGT, MAARTENSSON, BENGT
Applicants: METALLAATERVINNING AB
Application year: 1991
Main classification: E01F15
IPC codes: E01F15