Patent Description:
Impact-attenuating devices as in <CIT> are used to increase safety on and around a roadway, mainly in the vicinity of roadworks or other temporary or altered traffic situations. The operating principle of impact-attenuating devices is that, when a vehicle collides therewith, they absorb at least part of the kinetic energy of the colliding vehicle, whereby this vehicle can be brought to a standstill in a safe manner. On the one hand an area, such as a roadworks site, is screened off by the impact-attenuating device in this way, and any people present in this area are protected from collisions by vehicles that often approach such areas at excessive speeds. On the other hand, the one or more occupants of the colliding vehicle are protected in that the vehicle is brought to a gradual standstill, which decreases the chances of injury or worse as compared to the event wherein the vehicle comes to an abrupt standstill.

The main function of impact-attenuating devices is therefore to absorb kinetic energy. It is further important for impact-attenuating devices to be easily transportable. This is because they are utilized at different locations, and often have to be able to reach a location quickly. Mobile impact-attenuating devices are known and typically have the option of being transported in compact manner. For the actual purpose of a safe impact attenuation a long impact-attenuating device is however desirable, and these mobile impact-attenuating devices therefore typically consist of separate parts which are disposed one behind the other at the desired location. Such impact-attenuating devices however have the drawback that they absorb kinetic energy in less efficient manner, and are therefore less safe.

Embodiments of the invention have the object of providing an impact-attenuating device, particularly an impact-attenuating device which can be transported easily and guarantees a high degree of safety. It is a further object of embodiments of the invention to provide an impact-attenuating device which is able to bring a vehicle to a standstill gradually.

A first aspect of the invention relates to an impact-attenuating device comprising a first energy-absorbing part which comprises at least one first elongate body and at least one corresponding first energy converter, wherein the first elongate body and the first energy converter are movable relative to each other and wherein the first energy converter is configured to deform the first elongate body in the case of relative movement. The impact-attenuating device further comprises a second energy-absorbing part which comprises at least one second elongate body and at least one corresponding second energy converter, wherein the second elongate body and the second energy converter are movable relative to each other and wherein the second energy converter is configured to deform the second elongate body in the case of relative movement. The impact-attenuating device further comprises a bumper which is coupled to the first energy-absorbing part. The first and second energy-absorbing part can be positioned substantially one behind the other. The first and second energy-absorbing part are mutually coupled such that the at least first elongate body and the at least second elongate body are deformed at least partially simultaneously by respectively the at least one corresponding first energy converter and the at least one corresponding second energy converter when a colliding vehicle crashes into the bumper.

The impact-attenuating device is based on the inventive insight that, by allowing a simultaneous deformation of the first and second elongate body, a more uniform energy absorption is obtained as compared to known impact-attenuating devices. In other words, by coupling the first and second energy-absorbing part in such a manner in a set-up state a safe impact-attenuating device is provided which can be easily transported.

The first and second energy converters preferably comprise respectively first and second cutting means which are configured to cut respectively the first and second elongate bodies.

In this way part of the kinetic energy of the colliding vehicle is absorbed by means of cutting force. The first and second energy converters preferably comprise respectively a first and second bending part configured to bend respectively the first and second elongate bodies.

In this way part of the kinetic energy of the colliding vehicle is absorbed by means of bending or deformation of the first and/or second elongate body. An initial part of the kinetic energy which corresponds to an initial (high) speed of the colliding vehicle is preferably absorbed by cutting of the first and/or second elongate body. A remaining part of the kinetic energy, which corresponds to a lower speed of the colliding vehicle, is preferably absorbed by the bending or deformation of the first and/or second elongate body. This is advantageous because the cutting resistance rises sharply when the cutting speed drops below a threshold value whereby a final peak in the deceleration of the colliding vehicle would be caused. Such a final peak has the result that the colliding vehicle comes to an abrupt standstill, which would be detrimental to the safety of the occupants. By combining the cutting of the elongate bodies with the deformation or bending of the elongate bodies the final peak in the deceleration of the colliding vehicle can be avoided. This effect is intensified further in that kinetic energy is also absorbed by friction which occurs during the bending of the first and/or second elongate body, and/or by inertia which occurs when the components of the first and/or second energy-absorbing part are set into motion.

It will be apparent to the skilled person that the different forms of energy absorption, such as cutting and bending, take place during the entire process of bringing the colliding vehicle to a standstill. The different forms of energy absorption thus occur at both low and high speeds. A ratio or distribution at a given moment between these different forms of energy absorption will however differ depending on the energy to be absorbed and so the speed of the colliding vehicle. This ratio at a given moment will change over the course of time as the speed changes, precisely because the different forms of energy absorption depend on the speed in different ways.

The first and second energy-absorbing parts preferably have mutually differing conversion resistances. Conversion resistance is understood to mean the conversion resistance for the same speed. In other words, if the first and second energy-absorbing parts were to convert the kinetic energy of a colliding vehicle with a determined speed independently of each other, the different conversion components such as cutting resistance, deformation resistance, friction and inertia would result in a mutually differing resistance resultant. In practice the first energy-absorbing part will typically be subjected to a higher speed than the second energy-absorbing part, whereby similar forces are absorbed by the two energy-absorbing parts.

In this way the impact-attenuating device can use different resistance components in advantageous manner. This results in a quasi-self-regulating impact-attenuator which filters peaks from the deceleration profile in mechanical manner. In other words, a uniform deceleration is obtained by the diversity of available conversion components in the different energy-absorbing parts and by coupling of the respective energy-absorbing parts, this irrespective of the speed and/or mass of the colliding vehicle.

The first energy-absorbing part preferably has a first deformation resistance and the second energy-absorbing part a second deformation resistance, wherein the first deformation resistance is smaller than the second deformation resistance.

The first and second energy-absorbing parts are preferably mutually coupled by means of a coupling which is configured to partially block relative movement of the first energy-absorbing part and the second energy-absorbing part in a set-up state of the impact-attenuating device. A possible coupling is a lock or sliding lock.

The first energy-absorbing part preferably comprises an interlocking means which is configured on the one hand to block relative movement of the first elongate body and the first energy converter when a force exerted on the interlocking means is smaller than a predetermined threshold value and, on the other hand, to release relative movement of the first elongate body and the first energy converter when the force exerted on the interlocking means is greater than the predetermined threshold value. An example of such an interlocking means comprises one or more shear pins.

In this way it is ensured that the energy-absorbing action of the first energy-absorbing part is not used until the impact-attenuating device has been set up and a crash or collision takes place. The impact-attenuating device can thus be transported in a safe manner.

The second energy-absorbing part preferably comprises an interlocking means which is configured on the one hand to block relative movement of the second elongate body and the second energy converter when a force exerted on the interlocking means is smaller than a predetermined threshold value and, on the other hand, to release relative movement of the second elongate body and the second energy converter when the force exerted on the interlocking means is greater than the predetermined threshold value. An example of such an interlocking means is a shear pin.

In this way it is ensured that the energy-absorbing action of the second energy-absorbing part is not used until the impact-attenuating device has been set up and a crash or collision takes place. The impact-attenuating device can thus be transported in a safe manner.

The first and second energy converters preferably comprise respectively a first and second guide part which are arranged to guide respectively the first and second elongate bodies in the first and second energy converters.

The first and second energy converters are preferably respectively arranged at an outer end of respectively the first and second elongate bodies. It will however be apparent to the skilled person that the energy converters can also be arranged elsewhere.

The first energy converter is preferably arranged at an outer end of the first elongate body which is directed away from the bumper. It will however be apparent to the skilled person that the first energy converter can also be arranged elsewhere.

The second energy converter is preferably arranged at an outer end of the second elongate body which is directed toward the bumper. It will however be apparent to the skilled person that the second energy converter can also be arranged elsewhere.

The first and/or second cutting means preferably comprise at least two cutting surfaces. It will be apparent to the skilled person that the at least two cutting surfaces are formed by means of one blade, two blades or more blades. The two cutting surfaces are preferably mutually adjacent. The two cutting surfaces are further preferably disposed in an angular configuration, wherein the open legs of the angle are directed toward the elongate body in question. The two cutting surfaces form a cutting surface pair and co-act in order to cut the elongate body in question along a cutting line. It will be apparent to the skilled person that the first and/or second cutting means can comprise a plurality of cutting surface pairs for cutting the elongate body in question along multiple corresponding cutting lines.

The first and/or second cutting means preferably comprise a plurality of cutting surface pairs which are positioned such that they cannot come into contact with the elongate body in question simultaneously.

In this way the force absorption is built up gradually.

The plurality of cutting surface pairs are preferably disposed substantially parallel relative to each other.

The elongate bodies preferably comprise tubular profiles.

The tubular profiles preferably have a substantially rectangular cross-section. The tubular profiles more preferably have a substantially square cross-section. It will however be apparent to the skilled person that the cross-section of the tubular profiles can be substantially round or substantially hexagonal or octagonal. Other cross-sectional shapes are also possible.

The tubular profiles are preferably provided at an outer end thereof with at least one guiding recess. Such a guiding recess is also referred to as slip hole.

When such a guiding recess is encountered, the cutting is interrupted. This provides for a build-up of force over a longer distance and a reduced chance of a pressure surge. A gradually increasing force absorption is therefore achieved in this way.

The first and/or second bending part is preferably configured to bend the respective first and/or second elongate body through an angle of between <NUM>° and <NUM>°, more preferably between <NUM>° and <NUM>°, still more preferably between <NUM>° and <NUM>°, still more preferably between <NUM>° and <NUM>°, and most preferably between <NUM>° and <NUM>°.

The first energy-absorbing part and the second energy-absorbing part are preferably mutually slidable between an extended state, wherein the first and second energy-absorbing parts are placed substantially one behind the other, and a retracted state wherein the first and second energy-absorbing parts are placed substantially adjacently of each other.

The impact-attenuating device preferably comprises a coupling means for coupling to a tilting mechanism, wherein the impact-attenuating device is tiltable between a substantially horizontal operative state and a substantially vertical transport state.

The first energy-absorbing part preferably comprises two first elongate bodies and two corresponding first energy converters, wherein the two first elongate bodies extend substantially parallel relative to each other.

The second energy-absorbing part preferably comprises two, more preferably four, second elongate bodies and two, more preferably four, corresponding second energy converters, wherein the two, more preferably four, second elongate bodies extend substantially parallel relative to each other.

A second aspect of the invention relates to a vehicle and/or trailer comprising an impact-attenuating device.

It will be apparent to the skilled person that the measures and advantages associated with the above described embodiments of the impact-attenuating device according to the first aspect of the invention apply similarly, mutatis mutandis, to a vehicle and/or trailer according to the second aspect of the invention.

An impact-attenuating device according to any one of the foregoing embodiments is used in protecting a roadway or roadworks site. It will be apparent to the skilled person that the measures and advantages associated with the above described embodiments of the impact-attenuating device according to the first aspect of the invention apply similarly, mutatis mutandis, to the use of the impact-attenuating device.

The above stated and other advantageous features and objects of the invention will become more apparent, and the invention better understood, on the basis of the following detailed description when read in combination with the accompanying drawings, in which:.

<FIG> show an embodiment of an impact-attenuating device <NUM>. The impact-attenuating device <NUM> comprises a first energy-absorbing part <NUM> and a second energy-absorbing part <NUM>. The first energy-absorbing part <NUM> and the second energy-absorbing part <NUM> are positioned substantially one behind the other in a set-up state of the impact-attenuating device <NUM>. The first energy-absorbing part <NUM> comprises a first elongate body <NUM> and a corresponding first energy converter <NUM>. The first elongate body <NUM> and the first energy converter <NUM> are movable relative to each other. The first energy converter <NUM> is configured to deform the first elongate body <NUM> in the case of relative movement. The first elongate body <NUM> will thus for instance be deformed when it is pushed through the first energy converter <NUM> when a vehicle collides with the bumper <NUM> which is coupled to the first energy-absorbing part. The second energy-absorbing part <NUM> comprises a second elongate body <NUM> and a corresponding second energy converter <NUM>. The second elongate body <NUM> and the second energy converter <NUM> are movable relative to each other. The second energy converter <NUM> is configured to deform the second elongate body <NUM> in the case of relative movement. The first and second energy-absorbing parts <NUM>, <NUM> are coupled to each other such that the first elongate body <NUM> and the second elongate body <NUM> are deformed at least partially simultaneously by respectively the corresponding first energy converter <NUM> and the corresponding second energy converter <NUM> when a vehicle crashes into bumper <NUM>. The coupling that provides therefor is shown schematically as element <NUM>. This coupling <NUM> ensures that when a force is exerted on first energy converter <NUM>, for instance due to a collision, this force brings about a movement of the second energy converter <NUM> relative to the second elongate body <NUM>. In this way it is achieved that first energy-absorbing part <NUM> and second energy-absorbing part <NUM> are simultaneously active for the longest possible period of time. This ensures that the energy of a collision can be absorbed uniformly because several energy-absorbing elements co-act in order to prevent peaks in the energy absorption, i.e. the deceleration of the colliding vehicle. It will be apparent to the skilled person that the coupling <NUM> can be designed in different ways resulting in the above-described objective. Without limiting the scope of protection thereto, an advantageous embodiment of such a coupling <NUM> is described with reference to the embodiment of <FIG> and <FIG>.

The first and second energy converters <NUM>, <NUM> comprise respectively first and second cutting means 112a, 122a configured to cut respectively the first and second elongate bodies <NUM><NUM>. By cutting the elongate bodies energy from the collision or crash is absorbed. The elongate bodies are formed by tubular profiles having a substantially square cross-section. It will however be apparent to the skilled person that tubular profiles with other cross-sections can be used in the present impact-attenuating device, such as rectangular, hexagonal, octagonal, round and so on. The cutting means can each comprise one or more cutting surfaces. The elongate body in question can thus be cut into two or more pieces, depending on the configuration of the one or more cutting surfaces. Without limiting the scope of protection thereto, several advantageous preferred embodiments of the cutting means 212a are shown with reference to <FIG> and <FIG>.

The shown first and second energy converters <NUM>, <NUM> also have respectively a first and second bending part 112b, 122b, which are situated downstream of the cutting means 112a, 122a and are configured to bend the cut first and second elongate bodies <NUM>, <NUM>. The energy can hereby be further absorbed in efficient manner by bending the cut parts of the elongate bodies, by the friction created during the bending and/or by the mass inertia of the different components which are set into motion. The overall energy of the colliding vehicle is hereby absorbed in efficient and uniform manner. This is because known impact-attenuating devices which are based mainly on cutting force have the drawback that a final peak is caused in the energy absorption, and so in the deceleration profile of the colliding vehicle. This is detrimental to the safety of the occupants of the vehicle.

<FIG> and <FIG> show preferred embodiments of (parts of) an energy converter <NUM> which can be used in the first and/or second energy-absorbing parts. <FIG> show energy converters <NUM> which comprise a guide part 212c, cutting means 212a and a bending part 212b.

<FIG> shows a detail view of the cutting means 212a according to an embodiment. The guide part 212c ensures that the tubular profile <NUM> in question is guided in efficient manner in the direction of the cutting means 212a, indicated by arrow B in <FIG>, in the case of a collision. This contributes advantageously to the correct cutting of the tubular profile <NUM>. Cutting means 212a comprise one or more blades <NUM>. Without limiting the scope of protection thereto, different advantageous preferred embodiments of blades <NUM> are shown in <FIG>. It will however be apparent to the skilled person that other arrangements and forms of blades <NUM> are applicable in the impact-attenuating device. After tubular profile <NUM> has been cut by blades <NUM> the cut parts are guided through bending part 212b and bent. The shown bending parts 212b are configured to bend the cut parts through a substantially right angle. In this way it is ensured that the cut and bent parts of the tubular profile are discharged in safe manner, without endangering the occupants of the colliding vehicle or any bystanders here. It will however be apparent to the skilled person that the cut parts of the tubular profile can also be bent through a different angle, for instance through an angle of between <NUM>° and <NUM>°, preferably between <NUM>° and <NUM>°, more preferably between <NUM>° and <NUM>°, and still more preferably between <NUM>° and <NUM>°.

The blades <NUM> are preferably disposed substantially parallel relative to each other. In advantageous embodiments the blades are disposed such that they do not come into initial contact with the elongate body in question simultaneously. As shown in <FIG> and <FIG>, the blades are positioned with an offset relative to each other. In this way it is ensured that the energy absorption is built up gradually. By using each blade, cutting surface or cutting surface pair individually and in succession the cutting force which absorbs the energy is built up over a longer distance, and this decreases the chance of a pressure surge. Alternatively or in addition to the positioning of the blades <NUM>, the tubular profile <NUM> can advantageously be designed to contribute to the uniform buildup of the force, and so to the uniform absorption of the energy. In the embodiments of <FIG> and <FIG> tubular profile <NUM> is formed at an outer end thereof directed toward blades <NUM> such that a side, in this case the upper side, of the tubular profile <NUM> protrudes relative to an opposite side, in this case the underside, of the tubular profile <NUM>. This also contributes to a gradual buildup of the force used to absorb the energy of a colliding vehicle. In the embodiment of <FIG> four cutting surface pairs 213a, 213b, 213c and 213d are thus formed, these coming into contact with tubular profile <NUM> in turns. The shown cutting surface pairs 213a, 213b, 213c and 213d (indicated by "<" in <FIG>) are formed by an oblique side of the arranged blades <NUM>, the first cutting surface of the cutting surface pair, and an adjacent side of a housing of cutting means 212a, the second cutting surface of the cutting surface pair. Each cutting surface pair 213a, 213b, 213c and 213d will thus operate according to a principle of opened scissors and successively engage on tubular profile <NUM>. Cutting surface pair 213b will first engage on the upper side of the tubular profile, followed by cutting surface pairs 213d and 213a, and, finally, cutting surface pair 213c will engage on tubular profile <NUM>.

Alternatively or in addition to the above described measures, the tubular profile can be provided at an outer end thereof with at least one guiding recess. The tubular profile is preferably provided at an outer end directed toward cutting means 212a and in one or more walls of the tubular profile with holes serving as guiding recess. Providing these holes, which can have different shapes, further achieves that the cutting force which absorbs the energy is built up over a longer distance and in uniform manner.

It is noted that the energy converters and components thereof shown in <FIG> can be used as first and/or second energy converter in respectively the first and/or second energy-absorbing part of the present impact-attenuating device. It will further be apparent that specific features of different embodiments are mutually interchangeable or replaceable.

In the embodiment of <FIG> the first energy-absorbing part <NUM> consists of a first elongate body <NUM> and a corresponding first energy converter <NUM>. The second energy-absorbing part <NUM> consists of a second elongate body <NUM> and a corresponding second energy converter <NUM>. In further preferred embodiments the first energy-absorbing part comprises two or more first elongate bodies and corresponding first energy converters, and the second energy-absorbing part comprises two or more second elongate bodies and corresponding second energy converters. It is an advantage of several embodiments that similar elongate bodies and energy converters can be used in the first and second energy-absorbing part. In other words, the first and second energy-absorbing part can be formed by a well-chosen combination of elongate body and corresponding energy converter. Use thus need not be made of different components for the different energy-absorbing parts, but the same components can be used in modular manner. The production costs are hereby relatively low compared to other impact-attenuating devices comprising more different components.

<FIG> show an embodiment of an impact-attenuating device <NUM> wherein the first energy-absorbing part <NUM>, which is connected to the bumper <NUM>, comprises two first elongate bodies <NUM>, <NUM>' and two corresponding first energy converters <NUM>, <NUM>'. The second energy-absorbing part <NUM>, which can be connected to a vehicle, trailer and/or tilting mechanism (not shown), comprises four second elongate bodies <NUM>, <NUM>', <NUM>" and <NUM>" ' and four corresponding second energy converters <NUM>, <NUM>', <NUM>" and <NUM>'". The first energy-absorbing part <NUM> and the second energy-absorbing part <NUM> are movable relative to each other between a set-up state, wherein the first and second energy-absorbing part <NUM>, <NUM> are placed substantially one behind the other, and a compact state wherein the first and second energy-absorbing parts <NUM>, <NUM> are placed substantially adjacently of each other. <FIG>, <FIG> and <FIG> show different views of the impact-attenuating device <NUM> in the set-up state. <FIG>, <FIG> and <FIG> show different views of the impact-attenuating device <NUM> in compact state. In the shown embodiments the set-up state corresponds with a setup wherein the first energy-absorbing part <NUM> has been extended forward (in the direction of the bumper) relative to the second energy-absorbing part <NUM>, and the compact state corresponds with a setup wherein the first energy-absorbing part <NUM> has been retracted to a position between or adjacently of the second energy-absorbing part <NUM>. The compact state can for instance be used for transporting impact-attenuating device <NUM> in efficient and safe manner. In the shown embodiment the first and second energy-absorbing parts <NUM>, <NUM> are slidable relative to each other. It will however be apparent to the skilled person that the energy-absorbing parts <NUM>, <NUM> can be similarly rotatable, tiltable, movable and/or pivotable relative to each other between a set-up state and a compact state. In the set-up state the distance between bumper <NUM> and the opposite outer end of the second energy-absorbing part is greater than in the compact state. The distance between bumper <NUM> and the opposite outer end of the second energy-absorbing part, which can be connected to a coupling, is preferably maximal.

The two first elongate bodies <NUM>, <NUM>' are mutually parallel and extend adjacently of each other. alternatively or additionally, the first elongate bodies can also extend above and below each other. The two first elongate bodies <NUM>, <NUM>' are both connected to the bumper and are placed in corresponding two first energy converters <NUM>, <NUM>' at the outer ends positioned opposite the bumper. In the case of an impact against the bumper the two first elongate bodies <NUM>, <NUM>' will be pushed through the corresponding two first energy converters. It will however be apparent to the skilled person that one or two of the two first energy converters <NUM>, <NUM>' can be situated at the outer end coupled to the bumper. The energy converter in question is then pushed "over" the corresponding elongate body. In any case, there will be relative movement between the elongate body and the corresponding energy converter, and the elongate body will hereby be accelerated and/or bent. The elongate body is preferably first cut and then bent and/or deformed, as discussed above with reference to <FIG>.

The four second elongate bodies <NUM>, <NUM>', <NUM>" and <NUM>‴ are mutually parallel and extend adjacently of and/or above/below each other. In a view looking from bumper <NUM> to the four second elongate bodies <NUM>, <NUM>', <NUM>" and <NUM>" ' the position of each of the four second elongate bodies <NUM>, <NUM>', <NUM>" and <NUM>" ' corresponds with the corner point of a rectangle.

In the compact state the two first elongate bodies <NUM>, <NUM>' are situated more or less between (in the view of <FIG>) and adjacently of (in the view of <FIG>) the four second elongate bodies <NUM>, <NUM>', <NUM>" and <NUM>'".

Due to mechanical considerations, the various components of the first and second energy-absorbing part <NUM>, <NUM> are mounted in a frame which allows the functionality described in this text. On the basis of the description in this text the skilled person can realize such a frame in different ways. The exact embodiment of the frame therefore does not form the subject of this patent application.

The four second energy converters <NUM>, <NUM>', <NUM>" and <NUM>‴ are positioned at the outer ends of the four second elongate bodies <NUM>, <NUM>', <NUM>" and <NUM>‴ directed toward the bumper. It will however be apparent to the skilled person that, on the basis of the principle of mechanical reversal, one or more of the four second energy converters <NUM>, <NUM>', <NUM>" and <NUM>‴ can be situated at the outer end of the relevant second elongate body remote from the bumper. The two first energy converters <NUM>, <NUM>' and four second energy converters <NUM>, <NUM>', <NUM>" and <NUM>‴ are formed according to one of the embodiments as shown in <FIG> or a combination thereof. So as to avoid repetition, the energy converters <NUM>, <NUM>', <NUM>, <NUM>', <NUM>" and <NUM>‴ are not described at length here.

The first and second energy-absorbing parts <NUM>, <NUM> have mutually differing conversion resistances, in this case due to the mutually differing construction. This means that the first energy-absorbing part <NUM> and the second energy-absorbing part <NUM> will contribute to the energy absorption to greater or lesser extent relative to each other when they are considered individually and at rest. The first energy-absorbing part <NUM> preferably has a first conversion resistance smaller than a second conversion resistance of the second energy-absorbing part <NUM>. In other words, the second energy-absorbing part <NUM> is able to absorb more energy than the first energy-absorbing part <NUM>. This difference however no longer applies during operation wherein the first and second energy-absorbing part <NUM>, <NUM> of the impact-attenuating device <NUM> are coupled in specific manner.

The first and second energy-absorbing parts <NUM>, <NUM> are coupled to each other in the set-up state by means of a coupling <NUM> which is configured to block relative movement of the first energy-absorbing part <NUM> and the second energy-absorbing part <NUM>. During operation the components of the first energy-absorbing part <NUM> and the components of the second energy-absorbing part <NUM> hereby largely co-act to convert the kinetic energy of a colliding vehicle in uniform manner and so absorb it. As mentioned above, this co-action of the parts <NUM>, <NUM> placed one behind the other ensures that peaks are filtered from the deceleration profile of the colliding vehicle. A preferred embodiment of such a coupling <NUM> is discussed in more detail with reference to <FIG>, particularly <FIG>. It will be apparent to the skilled person that the coupling <NUM> has a released or open state and a coupled or closed state. In the released state of coupling <NUM> the first and second energy-absorbing parts <NUM>, <NUM> can be moved as a whole relative to each other. In the closed state of coupling <NUM> this is not possible. The coupling <NUM> can be brought into the open or closed state manually or remotely. Coupling <NUM> can take a single or multiple form. This means that the coupling <NUM> can engage at one specific location or at two or more locations in order to couple the first and second energy-absorbing parts <NUM>, <NUM> to each other.

The first energy-absorbing part <NUM> preferably comprises an interlocking means configured on the one hand to block relative movement of the first elongate body <NUM> and the first energy converter <NUM> when a force exerted on the interlocking means is smaller than a predetermined threshold value and, on the other hand, to release relative movement of the first elongate body <NUM> and the first energy converter <NUM> when the force exerted on the interlocking means is greater than the predetermined threshold value.

Similarly, the second energy-absorbing part <NUM> preferably comprises an interlocking means which is configured on the one hand to block relative movement of the second elongate body <NUM> and the second energy converter <NUM> when a force exerted on the interlocking means is smaller than a predetermined threshold value and, on the other hand, to release relative movement of the second elongate body <NUM> and the second energy converter <NUM> when the force exerted on the interlocking means is greater than the predetermined threshold value. A preferred embodiment of such an interlocking means is discussed in more detail with reference to <FIG>, particularly <FIG>.

<FIG> shows a top view of an impact-attenuating device <NUM> which is similar to the embodiment as shown in <FIG>. Further shown in <FIG> is a coupling <NUM>, by means of which the second energy-absorbing part <NUM> is coupled to a tilting installation <NUM>, and a drive system <NUM> for bringing about the above-described relative movement of the first and second energy-absorbing part <NUM>, <NUM>.

<FIG> shows a detail view in the direction of arrow 4B in <FIG>.

<FIG> shows a detail view in the direction of arrow 4C in <FIG>.

<FIG> and <FIG> show a coupling <NUM>, which is discussed in more detail with reference to <FIG>. In this case this is a double coupling <NUM> which engages on both the side of arrow 4B (<FIG>) and the side of arrow 4C (<FIG>) on the first and second energy-absorbing parts <NUM>, <NUM>. It will be apparent to the skilled person that the coupling <NUM> can also take the form of a single or multiple coupling. The coupling <NUM> is brought about when the impact-attenuating device <NUM> is in the set-up, extended state. In the shown embodiment the coupling takes the form of sliding lock <NUM>. Two plates with a slot <NUM> are provided on first energy-absorbing part <NUM>. When the first energy-absorbing part <NUM> is in its most extended state, a lock plate <NUM>, which is arranged on the second energy-absorbing part <NUM>, will be positioned precisely between them. The slot of lock plate <NUM> then corresponds with the slots of plates <NUM>. A passage <NUM> through these three parts <NUM>, <NUM> allows the whole to be locked. Between the frame <NUM> of first energy-absorbing part <NUM> and a gliding plate <NUM> the sliding plate <NUM> of the lock can slide through the opening <NUM>.

<FIG> shows a detail view of energy converter <NUM> which is provided with an interlocking means <NUM> configured on the one hand to block relative movement of the first elongate body <NUM> and the first energy converter <NUM> when a force exerted on interlocking means <NUM> is smaller than a predetermined threshold value and, on the other hand, to release relative movement of the first elongate body <NUM> and the first energy converter <NUM> when the force exerted on interlocking means <NUM> is greater than the predetermined threshold value. In <FIG> the interlocking means <NUM> is formed by means of two pairs of shear pins <NUM>, <NUM>. The shear pins <NUM>, <NUM> ensure that the elongate body <NUM> is not cut and/or bent unintentionally by the energy converter <NUM>. When the impact-attenuating device <NUM> is in the set-up state, and when an impact against the bumper takes place, shear pins <NUM>, <NUM> will break and thus allow a relative movement of the elongate body <NUM> and the energy converter <NUM>. It will be apparent to the skilled person that the interlocking means <NUM> can be realized in other ways and that the interlocking means <NUM> must not be limited by the specific shown embodiment. It will further be apparent to the skilled person that interlocking means <NUM> can comprise one or more shear pins, which can be positioned in different ways.

Claim 1:
Impact-attenuating device (<NUM>), comprising
a first energy-absorbing part (<NUM>) comprising at least one first elongate body (<NUM>) and at least one corresponding first energy converter (<NUM>), wherein the first elongate body and the first energy converter are movable relative to each other and wherein the first energy converter is configured to deform the first elongate body in the case of relative movement;
a second energy-absorbing part (<NUM>) comprising at least one second elongate body (<NUM>) and at least one corresponding second energy converter (<NUM>), wherein the second elongate body and the second energy converter are movable relative to each other and wherein the second energy converter is configured to deform the second elongate body in the case of relative movement;
a bumper (<NUM>) coupled to the first energy-absorbing part (<NUM>);
wherein the first and second energy-absorbing part can be positioned substantially one behind the other;
characterised in that the first (<NUM>) and second (<NUM>) energy-absorbing part are mutually coupled such that the at least first elongate body (<NUM>) and the at least second elongate body (<NUM>) are deformed at least partially simultaneously by respectively the at least one corresponding first energy converter (<NUM>) and the at least one corresponding second energy converter (<NUM>) when a vehicle crashes into the bumper (<NUM>).