WO2023105456A1

WO2023105456A1 - Telescopic impact attenuator

Info

Publication number: WO2023105456A1
Application number: PCT/IB2022/061911
Authority: WO
Inventors: Mauro Monteleone
Original assignee: Ingenieur Mauro Monteleone
Priority date: 2021-12-07
Filing date: 2022-12-07
Publication date: 2023-06-15
Also published as: CH719218A2

Abstract

The present invention relates to a telescopic impact attenuator (10) comprising one or more movable sledges (111, 112, 113) and a fixed sledge (114) arranged in line, wherein the movable sledges (111, 112, 113) are able to be telescopically moved between a stroke start position and a stroke end position, wherein the position of maximum extension of the telescopic impact attenuator (10) is defined when the movable sledges (111, 112, 113) arranged in the stroke start position and the position of minimum extension of the telescopic impact attenuator (10) is defined when the movable sledges (111, 112, 113) are arranged in the stroke end position, and wherein the telescopic impact attenuator (10) comprises a shock absorption device operatively coupled to the movable sledges (111, 112, 113) and comprising an hydraulic cylinder (211) able to be actuated by the movement of the movable sledges (111, 112, 113) along the axis of movement (X) to progressively reduce the impact energy generated by the collision of a vehicle against the telescopic impact attenuator (10).

Description

TELESCOPIC IMPACT ATTENUATOR

Field of the invention

The present invention relates to the field of road safety and to the use of road barriers.

The present invention relates, in particular, to a telescopic impact attenuator for attenuating the impact energy of a vehicle against a road barrier.

Prior art

Road safety is ensured by numerous devices including road barriers, which are installations capable of ensuring that a vehicle maintains the lane in the event of a collision or loss of control.

These road barriers allow vehicles to be kept in the lane but at the same time offer a structure suitable for absorbing the collisions to which they are subjected. Such collisions can result from a frontal impact or from a lateral impact of the vehicle, where the major problems for frontal impacts can be found on fast-moving roads or motorways.

In particular, the frontal impact is particularly critical at junctions, where the road forks into two branches. At the junction, in fact, the barriers of the two branches join at the union of the branches themselves, forming an acute angle which behaves like an anvil capable of causing greater damage than a simple lateral impact against the barrier.

In addition to the greater damage caused by the aforementioned anvil, even greater damage is caused, both to the vehicle and to its occupants, by the deceleration resulting from the impact, such as to determine, for example, the crushing and/or breakage of the internal organs of the occupants themselves which in many cases is lethal. Numerous protective devices are known which are suitable for defining impact attenuators capable of attenuating the impact energy of a vehicle against a road barrier.

US Patent Application No. 6116805 describes a compressible type impact attenuator, in particular comprising a plurality of deformable elements defined by suitable cerclages. The compression and consequent deformation of the aforementioned deformable elements is able to reduce the impact energy, but once the impact has taken place, these deformable elements need to be replaced as they have worn out their effectiveness.

US Patent Application No. 4674911 describes an impact attenuator of the compressible and reusable type defined by a plurality of air chambers arranged consecutively. The impact generates the compression of the chambers and, consequently, of the air inside them which is subsequently released through suitable pneumatic valves. This device, although effective in absorption, has a high cost and complexity with the risk that the pneumatic components are damaged at each impact. Furthermore, while being able to reduce the impact energy, the relative deceleration may not be very gradual while maintaining a high probability of impact trauma.

Patent Application IT no. 102015902336347 describes a compressible type impact attenuator comprising coaxial and telescopic impact attenuating elements, mutually sliding along a longitudinal sliding axis. These impact attenuating elements comprise a cavity which compresses during the reciprocal axial sliding following an impact, from a first position of maximum axial extension to a second position of minor axial extension to allow the absorption of energy through the progressive extraction of the air from the cavity itself. Even this device, although able to reduce the energy of the impact, has high production and maintenance costs, in particular high risks of damaging the attenuating elements at each impact. It would therefore be desirable to have an impact attenuator capable of minimizing the above drawbacks. In particular, it would be desirable to have an impact attenuator able to guarantee a high energy absorption while maintaining low production and maintenance costs.

Summary of the invention

The object of the present invention is to provide a telescopic impact attenuator able to minimize the aforementioned drawbacks.

Particularly, the object of the present invention is to provide a telescopic impact attenuator able to guarantees a controlled deceleration in the absorption of impact shock allowing a reduced maintenance.

The aforementioned object is achieved by a telescopic impact attenuator according to the attached claims.

The telescopic impact attenuator comprises one or more movable sledges and a fixed sledge arranged in line, wherein the movable sledges are able to be telescopically moved between a stroke start position and a stroke end position, and vice versa, along an axis of movement which is coaxial and extends from the starting portion to the ending portion of the telescopic impact attenuator, wherein the head sledge of the movable sledges is defined by the first of the movable sledges with respect to the starting portion, wherein the fixed sledge is arranged in the ending position, and wherein the position of maximum extension of the telescopic impact attenuator is defined when the movable sledges arranged in the stroke start position and the position of minimum extension of the telescopic impact attenuator is defined when the movable sledges are arranged in the stroke end position, the telescopic impact attenuator is characterized in that it comprises a shock absorption device operatively coupled to the movable sledges and comprising an hydraulic cylinder able to be actuated by the movement of the movable sledges along the axis of movement to progressively reduce the impact energy generated by the collision of a vehicle against the telescopic impact attenuator.

The movable sledges allow to modulate the impact avoiding a sudden stop of the vehicle, wherein the hydraulic cylinder allows to absorb the impact energy without the telescopic impact attenuator itself to be damaged.

According to an embodiment, the hydraulic cylinder is arranged on, and solidly coupled to, the head sledge.

Thus, the hydraulic cylinder is protected and moves together with the head sledge. According to an embodiment, the shock absorption device comprises a hoist operatively coupled to the hydraulic cylinder and to the movable sledges and able to actuate the hydraulic cylinder during the movement of the movable sledges along the axis of movement.

The combines use of the hydraulic cylinder and of the hoist allows the use of larger cylinders and with a greater absorption capacity as well, and without damaging the elements of the telescopic impact attenuator.

According to an embodiment, the hoist is arranged on, and solidly coupled to, the head sledge.

Thus, the hoist is protected and moves together with the head sledge.

According to an embodiment, the hoist comprises a fixed block and a movable block, wherein the fixed block is solidly coupled to the head sledge and the movable block is operatively coupled to the hydraulic cylinder and to the fixed block, and wherein the movement of the movable block is able to actuate the hydraulic cylinder during the movement of the movable sledges along the axis of movement. In particular, the movable block is able to be moved between an extension position, wherein the movable block is at the hydraulic cylinder and spaced from the fixed block, and a compression position, wherein the movable block is at the fixed block and spaced from the hydraulic cylinder, when the movable sledges are telescopically moved between the stroke start position and the stroke end position, and vice versa.

Thus, the movement of the movable block allows to actuate the hydraulic cylinder keeping the forces involved balanced, both in positioning towards the minimum extension and in positioning towards the maximum extension of the telescopic impact attenuator.

According to an embodiment, the fixed sledge is provided with a pair of side guides, wherein each of the movable sledges comprise respective pairs of side guides, and wherein the pairs of side guides are dimensioned in such a way as to allow the movement and the telescopic guidance of the movable sledges.

The guides allow to ensure the telescopic movement keeping the edges connected from the maximum extension to the minimum extension of the telescopic impact attenuator.

According to an embodiment, the telescopic impact attenuator comprises a base guide arranged at a floor plane along the axis of movement between the starting portion and the ending portion, and wherein the movable sledges are slidably constrained to the base guide to define the telescopic movement between the stroke start position and the stroke end position, and vice versa.

The base guide allows the controlled movement of the movable sledges, avoiding that these could move unintentionally along directions which are not parallel with respect to the coaxial axis of movement.

According to an embodiment, the telescopic impact attenuator comprises an oil tank provided with a first supply duct and a second supply duct arranged in fluid connection with the hydraulic cylinder, and wherein the first supply duct is operatively coupled at a first portion of the hydraulic cylinder and the second supply duct is operatively coupled at a second portion of the hydraulic cylinder.

Therefore, the supply ducts allow to define the resistance threshold according to different uses.

According to an embodiment, the telescopic impact attenuator comprises a motor suitable for repositioning the movable sledges into the stroke start position after the absorption of the impact energy generated by the collision of the vehicle.

Thus, it is possible to arrange the telescopic impact attenuator in a suitable configuration for automatically absorbing a further impact.

Description of the figures

These and further characteristics and advantages of the present invention will become apparent from the description of the embodiments, in which a preferred embodiment is illustrated by way of non-limiting example in the attached figures, wherein:

- Figure 1 shows a schematic side view of the telescopic impact attenuator according to the present invention, in an extended configuration;

- Figure 2 shows a schematic top view of the telescopic impact attenuator of Figure 1, in an extended configuration;

- Figure 3 shows a schematic top view of the telescopic impact attenuator of Figure 1, in a compressed configuration.

Detailed description of the invention

The present invention relates to a telescopic impact attenuator for use in the road field, suitable for attenuating the impact energy of a vehicle against a road barrier. Figures 1-3 illustrate a telescopic impact attenuator in accordance with the present invention in a preferred and non-limiting embodiment, indicated as a whole by the numeral 10.

This telescopic impact attenuator 10 is designed to allow the reduction of the impact energy generated by the deceleration of a vehicle against an obstacle, defined by the impact attenuator 10 itself, until it reaches a level such as not to cause fatal damage to the human body.

In detail, the telescopic impact attenuator 10 comprises a plurality of sledges 111, 112, 113, 114, identifying one or more mobile sledges, therefore able to be moved, and a fixed sledge, the position of which is fixed without the possibility of moving. In the present invention, the term “movable sledge ” means a device consisting of one or more metal components which can move, preferably by sliding, on suitable longitudinal, transversal or vertical guides, by both manual or mechanical movement.

In the present invention, the term “fixed sledge ” means a device consisting of one or more metal components fixed with respect to the guides onto which the movable sledges can move.

In particular, in the embodiment illustrated in the attached Figures 1-3, the telescopic impact attenuator 10 comprises three movable sledges, respectively indicated as a whole with the numbers 111, 112 and 113, and a fixed sledge, indicated as a whole with the number 114.

Taking into consideration the starting portion of the telescopic impact attenuator 10, defined by the portion adapted to receive the impact of the vehicle, and the ending portion of the same telescopic impact attenuator 10, defined by the portion opposite to the aforementioned starting portion, it is possible to identify the head sledge and the fixed sledge and its positioning. The head sledge, indicated as a whole by the number 111, is selected among the sledges 111, 112, 113 which are movable with respect to the aforesaid starting portion, being the first of the sledges which are movable with respect to this position. In the same way, it is possible to identify the fixed sledge 114 as a device disposed in the aforementioned ending portion.

In the embodiment illustrated therein, the telescopic impact attenuator 10 comprises a base guide 311 arranged at the floor level, or at the road level, along the movement axis X between the starting portion and the ending portion. In particular, the end of the base guide 311 where the fixed sledge 114 is arranged defines the aforementioned ending portion of the telescopic impact attenuator 10, while the opposite end defines the starting portion of the same telescopic impact attenuator 10.

The base guide 311 is configured to be installed on the road surface by dowelling and/or micro-posts, as illustrated in the side view of Figure 1, but according to further and not illustrated embodiments, different anchoring systems can be used. The aforementioned sledges 111, 112, 113, 114 are arranged coaxially aligned with respect to an axis of movement X which extends from the starting portion to the ending portion of the telescopic impact attenuator 10. The movable sledges 111, 112, 113 are, in fact, suitable for being telescopically moved between a stroke start position and a stroke end position, and vice versa, along the aforementioned coaxial axis of movement which extends from the starting portion to the ending portion of the telescopic impact attenuator 10.

In the embodiment described therein, the base guide 311 is defined by a pair of parallel tracks onto which the movable sledges 111, 112, 113 can be moved. Therefore, the movable sledges 111, 112, 113 have a pair of coupling portions configured to be operatively connected to the pair of parallel tracks of said base guide 311 and allow a linear movement avoiding misalignments.

According to further embodiments, not shown, the basic guide, if present, could be made according to different ways. In particular, the movable sledges 111, 112, 113 are slidably coupled to the base guide 311 to define the telescopic movement between the stroke start position and the stroke end position, and vice versa.

The base guide 311 therefore allows controlled movement of the mobile sledges 111, 112, 113, preventing them from inadvertently moving along directions that are not parallel to the coaxial axis of movement.

According to further embodiments, not shown, the telescopic impact attenuator could be devoid of the aforesaid base guide, thus allowing movement of the movable slides according to different ways or with respect to different guides.

In the present invention, the term “telescopic” means the possibility of the movable sledges to be inserted one inside the other, and possibly inside the fixed sledge during the respective movement.

The maximum extension position of the telescopic impact attenuator 10, illustrated in the schematic top view of Figure 2 as an extended condition, is defined when the movable sledges 111, 112, 113 are arranged in the stroke start position, while the position of minimum extension of the same telescopic impact attenuator 10, illustrated in the schematic top view of Figure 3 as a compressed condition, is defined when the movable sledges 111, 112, 113 are arranged in the stroke end position.

In detail, each of the sledges 111, 112, 113, 114 comprises a pair of tubular portions 111’, 111”, 112”, 113”, 114”, wherein the tubular conformation comprises any hollow solid geometric conformation having a constant section. In particular, each tubular portion respectively defines a tubular head portion 111’, and a tubular end portion 111”, 112”, 113”, 114”, solidly coupled in such a way as to be moved simultaneously and define the dimensions of each movable sledge 111, 112, 113. To allow the aforementioned telescopic movement, the aforementioned sledges 111, 112, 113, 114 are configured in such a way as to be smaller in size going from the starting portion to the ending portion of the telescopic impact attenuator 10, so that each head portion can be coupled, and at least partially inserted, within the end tubular portion 111”, 112”, 113” of the movable slide 111, 112, 113 arranged upstream, or which lays upstream, taking into account the aforementioned starting portion.

According to further embodiments, not shown, the sledges, both of movable or of fixed type, could be made according to different ways.

The movable sledges 111, 112, 113 are moved, i.e. slide on the base guide 311, in a linear maimer between the respective stroke start and stroke end positions, the latter being different for each of the movable sledges 111, 112, 113. In particular , the head sledge 111 has the greatest movement extension, being able to move until it at least partially incorporates the fixed sledge 114, while the last movable sledge 113 coupled with the fixed sledge 114 has the least movement extension, being able to move until it incorporates only and at least partially the fixed sledge 114. In the preferred embodiment, the fixed sledge 114 and the movable sledges 111, 112, 113 are respectively provided with a pair of side guides 514, 511, 512, 513. In particular, the aforementioned pairs of side guides 511, 512, 513, 514 are sized in such a way as to allow the movement and telescopic guide of the mobile sledges

111, 112, 113, between them and with respect to the same side guides 514 of said fixed sledge 114. Furthermore, as already described above for the sledges 111,

112, 113, 114, to allow telescopic movement, the respective side guides 511, 512, 513, 514 are also configured in such a way as to be smaller in size from the starting portion to the ending portion of the telescopic impact attenuator 10.

The side guides 511, 512, 513, 514 allow to ensure the telescopic movement by keeping the sledges 111, 112, 113, 114 connected from the position of maximum extension to the position of minimum extension of the telescopic impact attenuator 10.

According to further embodiments, not shown, the aforesaid side guides could not be present, or could be made according to different ways. Therefore, in the maximum extension position of the telescopic impact attenuator 10 only a minimal portion of each of the sledges 112, 113, 114 is introduced into the respective portions of the sledges 111, 112, 113 arranged upstream, while in the minimum extension position of the telescopic impact attenuator 10 each of the sledges 111, 112, 113 has the respective sledges 112, 113, 114 introduced in their maximum portion.

According to further embodiments, not shown, the base guide, if present, could be made according to different ways.

Furthermore, according to the embodiment described and illustrated therein, the number of movable sledges is equal to three, but any number of movable sledges can be employed, although at least one fixed sledge must be present.

The telescopic impact attenuator 10 according to the present invention is characterized in that it comprises a shock absorption device operatively coupled to the movable sledges 111, 112, 113. In particular, this absorption device comprises a hydraulic cylinder 211 adapted to be actuated by the movement of the movable sledges 111, 112, 113 along the axis of movement X to progressively reduce the impact energy generated by the collision of a vehicle against the telescopic impact attenuator 10 itself.

The hydraulic cylinder 211 is arranged on, and integrally coupled to, the head sledge 111, but could equally be arranged differently according to further embodiments not shown. Thus, the hydraulic cylinder 211 is protected and moves together with the head sledge 111.

As illustrated in Figures 2 and 3, the hydraulic cylinder 211 comprises a piston actuated within the chamber of the hydraulic cylinder 211 itself by means of a rod. According to further embodiments, not shown, it is possible to use hydraulic cylinders provided with a multi-rod actuation, thereby reducing their dimensions or increasing their braking force. The actuation of the cylinder is also ensured by an oil tank 411 in fluid connection with the hydraulic cylinder 211 to define a closed actuation circuit. In the preferred embodiment described therein, the oil tank 411 is provided with a first supply duct 412 and a second supply duct 413 arranged in fluid connection with the hydraulic cylinder 411 at two different portions of the same. In particular, the first supply duct 412 is operatively coupled to a first portion of the hydraulic cylinder 211 and the second supply duct 413 is operatively coupled to a second portion of the same hydraulic cylinder 211, the aforementioned portions being sufficiently spaced so that the supply ducts 412, 413 can allow to determine a resistance threshold suitable for different uses.

According to further embodiments, not shown, the oil tank could be provided with a single supply duct defining a single working threshold of the hydraulic cylinder, or more supply ducts eventually managed by suitable one-way or two-way valves able to define a greater number of higher working thresholds for the hydraulic cylinder.

The shock absorbing device further comprises a hoist 212 operatively coupled to the hydraulic cylinder 211 and to the movable sledges 111, 112, 113 and adapted to operate the hydraulic cylinder 211 during the movement of the movable sledges 111, 112, 113 along the axis movement X. In the present embodiment, the hoist 212 is also arranged on, and solidly coupled to, the head sledge 111. In this way, as already discussed for the hydraulic cylinder 211, the hoist 212 is protected and moves together to the head sledge 111.

A fixed block and a movable block, indicated respectively with the number 212’ and with the number 212”, define the aforementioned hoist 212. The fixed block 212’ defines the aforementioned integral coupling with the head sledge 111, being it arranged on the latter. The movable block 212”, also arranged on the head sledge 111, is operatively coupled to the hydraulic cylinder 211 and to the fixed block 212’ and defines the actuation of the same hydraulic cylinder 211. In particular, the movement of the movable block 212” is suitable for operating the hydraulic cylinder 211 during the movement of the movable sledges 111, 112, 113 along the axis of movement X.

Both in the fixed block 212’ and in the movable block 212” there are pulleys pivoted in whose grooves a rope is wound which guarantees the operation of the hoist 212. The number of pulleys of each element can be modified according to the design requirements and in the embodiment herewith illustrated it comprises a number equal to sixteen pulleys for the fixed block 212’ and the same number for the movable block 212”.

Figures 2 and 3 clearly define the connection of the hoist 212 with respect to the telescopic impact attenuator 10, where specifically the movable block 212” is integrally coupled to the stem of the hydraulic cylinder 211 to define its actuation. In addition, the sheaves of each block 212’, 212” are arranged on the sides of the rod so as to be balanced symmetrically. In this regard, the hydraulic cylinder 211 and, correspondingly, the rod are arranged centrally with respect to the head sledge 111 so as to guarantee the balancing of the forces involved during the actuation of the hydraulic cylinder 211 itself, i.e. of the telescopic impact attenuation 10 following an impact with the vehicle, avoiding any possible drifts.

The operation of the hoist 212 is therefore managed, as known, by the ropes wound on the respective pulleys, as previously described, the latter being further constrained to a portion of the telescopic impact attenuator 10 to define the towing position. As illustrated in Figures 1 and 2, in the embodiment described therein, these ropes are constrained to the starting portion of the telescopic impact attenuator 10, preferably centrally with respect to the arrangement of the aforementioned pulleys.

In particular, the movable block 212” is able to be moved between an extension position, illustrated in Figure 2 and in which the movable block 212” is at the hydraulic cylinder 211 and spaced from the fixed block 212’, and a compression position, illustrated in Figure 3 and in which the movable block 212” is at the fixed block 212’ and spaced from the hydraulic cylinder 211, when the mobile sledges 111, 112, 113 are moved telescopically between the stroke start position and the end position, and vice versa.

According to a further embodiment, not shown, the telescopic impact attenuator can comprise a pump suitable for repositioning the sledges in the stroke start position after absorbing the impact energy generated by the collision of the vehicle. In this way, it is possible to arrange the telescopic impact attenuator in the configuration suitable for automatically absorbing a further shock. This pump could be of the electric type, for example with remote control, in such a way as to modify the position of the telescopic impact attenuator at a distance, thus reducing the maintenance costs associated with it.

Finally, the telescopic impact attenuator 10 in the present embodiment is provided with a head guardrail 500 arranged at the head sledge 111 and suitable for protecting it. According to a further embodiment, not shown, on each of the side portions of the telescopic impact attenuator there may be a guardrail, which is configured to divert the trajectory of the vehicle when impacting against the telescopic impact attenuator according to the present invention from a direction to this lateral rather than frontal. This guardrail can be configured in a plurality of juxtaposed sections following an installation direction parallel to said axis of movement.

The dimensions of the telescopic impact attenuator 10, in accordance with the preferred embodiment, include a width equal to 1000mm and a height equal to 843mm, calculated with respect to the widest and highest sledge corresponding to the head sledge 111. The total length measured along the coaxial axis of movement X is equal to 5800mm, with decreasing length dimensions for each of the sledges from the head sledge 111, corresponding to the longest sledge with length equal to 1600mm, to the fixed sledge 114, with length equal at 1300mm. These dimensions may be subject to modifications in accordance with the technical design requirements.

In use, therefore, it is assumed that a vehicle impacts against the telescopic impact attenuator 10 object of the present invention at the initial portion, i.e. against the head guardrail 500, if present, and the head sledge 111, progressively compressing the remaining sledges 112, 113 movable along the direction of the coaxial axis of movement X therewith. These movable sledges 111, 112, 113 slide along the rails of the base guide 311 arranging the telescopic impact attenuator 10 from the position of maximum extension to the position of minimum extension, or to an intermediate position between these. In this regard, in fact, it is not said that the impact energy is such as to completely compress the telescopic impact attenuator 10, or to bring the movable sledges 111, 112, 113 against the fixed sledge 114. Having defined a number “n ” of movable sledges, the force necessary for the axial compression of the telescopic impact attenuator 10, or for its arrangement in the position of minimum extension, corresponding to the force which opposes to the vehicle at the time of shock or impact itself and in the subsequent deceleration, is directly proportional to the dimensions and technical characteristics of the hydraulic cylinder 211 and, if present, of the hoist 212.

In any case, the force necessary for the compression of all the elements can be such as to remain constant throughout the movement from the position of maximum extension to the position of minimum extension, for example when the hydraulic cylinder is provided with a single supply duct to the oil tank, i.e. have different levels of compressive force. The latter case is achieved by the preferred embodiment described therein, in which the first supply duct 412 and the second supply duct 413 feed the oil tank 411. In a first step, both ducts 412, 413 simultaneously supply the oil tank 411, defining a higher flow rate and, consequently, a lower force opposed to the impact. In this first phase, light vehicles can be slowed down and stopped without reaching the position of minimum extension of the telescopic impact attenuation 10. In a second phase, the first supply duct 412 is excluded due to the continuation of the stroke of the hydraulic cylinder 211 and, therefore, only the second supply duct 413 defines the lower flow rate to the oil tank 411 and, consequently, a higher force opposed to the impact. In this second phase, even heavy vehicles can be slowed down and stopped at most until reaching the position of minimum extension of the telescopic impact attenuator 10.

Therefore, the mobile sledges 111, 112, 113 allow to modulate the impact avoiding a sudden stop of the vehicle, initially modulating the force for light vehicles and subsequently for heavy vehicles, where the use of the hydraulic cylinder 211 allows to absorb the impact energy without generating damage to the telescopic impact attenuator 10 itself. In particular, the movement of the movable block 212” allows to actuate the hydraulic cylinder 211 keeping balanced the forces involved, both in positioning towards the minimum extension and in positioning towards the maximum extension of the telescopic impact attenuator 10.

Therefore, the combined use of the hydraulic cylinder 211 and the hoist 212 allows the use of larger cylinders with a greater absorption capacity and without damaging the elements of the telescopic impact attenuator 10 on impact.

Following the impact, the various elements defining the telescopic impact attenuator 10 are repositioned in the starting position of maximum axial extension, and the device object of the present invention is again ready to be used.

The telescopic impact attenuator according to the present invention therefore ensures a controlled deceleration in the absorption of impact shocks, at the same time allowing reduced maintenance as well as reduced production and installation costs.

Claims

1. A telescopic impact attenuator (10) comprising one or more movable sledges (111, 112, 113) and a fixed sledge (114) arranged in line, wherein said movable sledges (111, 112, 113) are able to be telescopically moved between a stroke start position and a stroke end position, and vice versa, along an axis of movement (X) which is coaxial and extends from the starting portion to the ending portion of said telescopic impact attenuator (10), wherein the head sledge (111) of said movable sledges (111, 112, 113) is defined by the first of said movable sledges (111, 112, 113) with respect to said starting portion, wherein said fixed sledge (114) is arranged in said ending position, and wherein the position of maximum extension of said telescopic impact attenuator (10) is defined when said movable sledges (111, 112, 113) arranged in said stroke start position and the position of minimum extension of said telescopic impact attenuator (10) is defined when said movable sledges (111, 112, 113) are arranged in said stroke end position, said telescopic impact attenuator (10) is characterized in that it comprises a shock absorption device operatively coupled to said movable sledges (111, 112, 113) and comprising an hydraulic cylinder (211) able to be actuated by the movement of said movable sledges (111, 112, 113) along said axis of movement (X) to progressively reduce the impact energy generated by the collision of a vehicle against said telescopic impact attenuator (10).

2. The telescopic impact attenuator (10) according to claim 1, wherein said hydraulic cylinder (211) is arranged on, and solidly coupled to, said head sledge (111).

3. The telescopic impact attenuator (10) according to claim 1 or 2, wherein said shock absorption device comprises a hoist (212) operatively coupled to said hydraulic cylinder (211) and to said movable sledges (111, 112, 113) and able to actuate said hydraulic cylinder (211) during said movement of said movable sledges (111, 112, 113) along said axis of movement (X). The telescopic impact attenuator (10) according to claim 2 and 3, wherein said hoist (212) is arranged on, and solidly coupled to, said head sledge (111). The telescopic impact attenuator (10) according to claim 4, wherein said hoist (212) comprises a fixed block (212’) and a movable block (212”), wherein said fixed block (212’) is solidly coupled to said head sledge (111) and said movable block (212”) is operatively coupled to said hydraulic cylinder (211) and to said fixed block (212’), and wherein the movement of said movable block (212”) is able to actuate said hydraulic cylinder (211) during said movement of said movable sledges (111, 112, 113) along said axis of movement (X). The telescopic impact attenuator (10) according to claim 5, wherein said movable block (212”) is able to be moved between an extension position, wherein said movable block (212”) is at said hydraulic cylinder (211) and spaced from said fixed block (212’), and a compression position, wherein said movable block (212”) is at said fixed block (212’) and spaced from said hydraulic cylinder (211), when said movable sledges (111, 112, 113) are telescopically moved between said stroke start position and said stroke end position, and vice versa. The telescopic impact attenuator (10) according to one of claims 1-6, wherein said fixed sledge (114) is provided with a pair of side guides (514), wherein each of said movable sledges (111, 112, 113) comprise respective pairs of side guides (511, 512, 513), and wherein said pairs of side guides (511, 512, 513, 514) are dimensioned in such a way as to allow the movement and the telescopic guidance of said movable sledges (111, 112, 113). The telescopic impact attenuator (10) according to one of claims 1-7, comprising a base guide (311) arranged at a floor plane along said axis of movement (X) between said starting portion and said ending portion, and wherein said movable sledges (111, 112, 113) are slidably constrained to said base guide (311) to define said telescopic movement between said stroke start position and said stroke end position, and vice versa. The telescopic impact attenuator (10) according to one of claims 1-8, comprising an oil tank (411) provided with a first supply duct (412) and a second supply duct (413) arranged in fluid connection with said hydraulic cylinder (211), and wherein said first supply duct (412) is operatively coupled at a first portion of said hydraulic cylinder (211) and said second supply duct (413) is operatively coupled at a second portion of said hydraulic cylinder (211). The telescopic impact attenuator (10) according to one of claims 1-9, comprising a motor suitable for repositioning said movable sledges (111, 112, 113) into said stroke start position after the absorption of said impact energy generated by the collision of said vehicle.

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