FR2899252A1 - Moving body e.g. stone, retrograding device for use on sloping land, has loop with wire connected to hitching elements of carrier element, where length of wire is sensibly lower than length of carrier element when device is at rest - Google Patents

Abstract

The device (1) has a carrier element (3) for retaining a metal thread (10) that permits to retrograde a moving body such as stone. A power dissipation loop (20) has a chain shaped fusible wire connected to hitching elements of the carrier element. Length of the wire is sensibly lower than the length of the carrier element, between the hitching elements, when the device is at rest, so that the wire absorbs whole or part of energy generated by the body when the carrier element is subjected to a force due to the body. The hitching elements connect the wire to the carrier element.

Description

DEVICE FOR BRAKING A BODY IN MOTION DESCRIPTION The present invention

  The invention relates to a device for braking a moving body, comprising a carrier element adapted to be fixed by a first part and adapted to be connected by a second part, either to a means for braking said moving body, or directly to the latter, which device comprises at least one energy dissipation loop, provided with at least one fuse connected to two fixing points of the carrier element, the length of the fuse being, when the device is at rest, substantially lower at the length of the carrier element between the two attachment points, so that when said carrier member is subjected to a force due to the moving body, said fuse absorbs all or part of the energy generated by the body in motion. movement.

  The present invention is especially adapted for stopping rock falls, on sloping ground, and in particular, a dynamic barrier stopping stone falls, in which the load-bearing elements comprise loops of energy dissipation. Protection barriers against falling rocks are generally made of a net held by posts across the predictable path of stones on sloping ground. The net consists of metal cables, for example stainless steel, whose frames can slide relative to each other at the nodes and mechanically linked by caliper cable clamps. The net is supported by guy wires connected to poles whose feet can be fixed or articulated at their foundation in the ground, the poles being stabilized by cables anchored in the ground upstream and downstream.

  During an impact by a block, part of the energy of the block is absorbed by deformation of the net at the level of the cable ties and the poles at their base and the elastic deformations also reduce the initial energy.

  However, this type of barrier is not always sufficient to stop in all circumstances the largest blocks likely to hit the slopes. Solutions have therefore been adopted to improve the effectiveness of barrier barriers. It was thus planned to attach the net on the posts by means of springs. But the improvement is limited because of the low possible elongation of the springs.

  A device according to the introduction is known from French patent FR 9705880. The device according to this patent is provided with the carrier elements in the form of cable. On this cable, between two attachment points, fusible cables are attached. These fusible cables are connected to the carrier cable, so that, at rest, the length of the fuse cable is substantially less than the length of the carrier cable between said attachment points. When the braking device according to this patent is used, the force of a moving body is transmitted from the carrier cable to the fuse cable. The fuse cable is then stretched under the effect of the tensile force exerted on the carrier cable, elongates and eventually breaks. This means that the fuse cable is able to absorb at least a portion of the kinetic energy of the moving body to slow down said moving body.

  The connection of the carrier cable and the fuse cable, according to FR9705880, is achieved by means of sliding or locking sleeves. This assembly requires to be performed using a hydraulic press in the workshop. A disadvantage of such an assembly is that it only allows the use of cable type materials and does not vary the materials used to manufacture the carrier element and the fuses. Another disadvantage is that after the first use and the resulting deterioration of the overall system, it is necessary to proceed with the change of the entire system. The assembly must then be transported to the workshop to repair the damaged fuses.

  In addition, the fixing of the fuse cable on the carrier cable, by means of a hydraulic press, results in the weakening of the carrier cable. For all these reasons, an object of the invention is to provide a moving body braking device, according to the introduction, allowing the replacement of fuses.

  3 damaged in situ, without the need to transport the braking device in the workshop and prepare the device for future use. The main object of the invention is therefore a moving body braking device, comprising a carrier element adapted to be fixed by a first portion and adapted to be connected by a second portion, or to a means for braking said body. in motion, or directly to the latter, which device comprises at least one energy dissipation loop, provided with at least one fuse connected to two fixing points of the carrier element, the length of the fuse being, when the device is at rest, substantially less than the length of the carrier element between the two attachment points, so that when said carrier member is subjected to a force due to the moving body, said fuse absorbs all or part of the energy generated by the moving body, wherein said carrier member is, at the attachment point, provided with a hooking member, for connecting the fuse to the carrier member to using this snap element.

  Thanks to the presence of the fastening elements on the fixing points, the user can take advantage of this fastening element to connect the fuses to the carrier element. Another technical effect is that, thanks to the presence of the attachment elements, it is possible to vary the nature of the materials used to manufacture the carrier element and the fuses. According to the invention, it is possible for the fastening elements to have the shape of a loop. According to a preferred embodiment, it is possible for the carrier element 30 to comprise, at least over a part of its length, a chain, and for said hooking element to be formed by a link of this chain.

  The presence of a loop or the presence of links greatly facilitates the possibility of connecting fuses to the carrier element. This means that after a first use of the braking device according to the invention, the user can easily hang new fuses on the carrier element. It does not need to carry the device to a place where there are special tools to connect these new fuses on the carrier.

  According to the invention, it is possible that the fuses are made of metal. Alternatively, it is possible that the fuses are made of an elastic material such as rubber.

  It should be understood that for the invention it is possible to use all materials that can absorb all or part of the energy generated by the moving body. In addition, it should be noted that in this text, the braking device is provided with a fuse. The fuse word is used to indicate the possibility of absorbing energy, for example by plastic or elastic deformation of the fuse.

  According to the invention, it is not forced that the fuse is broken during the braking of the moving body. It is quite possible for the fuse to undergo elastic deformation and, after use, to return to its original position.

  According to the invention, it is possible for at least a first and a second fuse to be connected to a first and a second attachment point of the carrier element. In addition, it is possible for the carrier element to comprise at least a first and a second energy dissipation loop.

  According to the invention, it is possible that the means for braking said bodies is a net. Thus, it is possible that said net is disposed between two posts anchored in the ground and held with the aid of the carrier element.

  The objects, objects and features of the invention will appear more clearly on reading the following description, with reference to the drawings in which: FIG. 1 shows a cross-section of a moving body braking device according to one embodiment of the invention,

  FIG. 2 shows a plan view of the device illustrated in FIG. 1; FIG. 3 shows a portion of the carrier element, provided with a first and a second fastening element, connected by a fuse, FIG. FIG. 4 represents the carrier element according to FIG. 3, after the rupture of the fuse,

  FIG. 5 shows a carrier element, provided with a first and a second fastening element, in which the fastening elements are connected to a first and a second fuse, in parallel, FIG. FIG. 7 shows a carrier element of the chain type, in which the links 15 are used for fastening fuses, FIG. Fig. 9 shows a string-type fuse in detail. Fig. 9 shows a thread with fuses prior to use and Fig. 10 shows the thread according to Fig. 9 after use. FIG. 1 shows the cross-section of a braking device of a moving body 1, installed along a contour line in a terrain 2. The braking device 1 is provided with a net 10, stowed in the ground 2 by means of posts 11, anchored to the ground. The net 10 is in principle metal. The net 10 is held by carrying elements 3 and stays 4 anchored to the ground by means of support plates 12 and anchors. The carrier member 3 is provided with one or more energy dissipation loops 20 for absorbing the energy of a moving body. Examples for carrying out the energy dissipation loops 20 are shown in FIGS. 3-8.10. The carrier elements 3 may, as in the example illustrated in FIG. 1, form a triangle by means of two pulleys 13, 14 or 14. of recesses located at the bottom and at the top of the posts 11.

  The braking device of a moving body 1, according to FIG. 1, is represented by a plan view in FIG. 2. FIG. 2 shows the fixing of the stays 4 between the columns 11 and the support plates 12.

  The operation of the moving body braking device 1 according to the invention is as follows:

  in the event of falling blocks of stones, the dissipation of kinetic energy of such a stone takes place, initially, thanks to the particular mesh of the net 10, 15 which allows, during the impact, to slide the cables forming the frame.

  The carrier elements 3 which can, as in the example illustrated in FIG. 1, form a triangle by means of the two pulleys 13, 14 or recesses situated at the bottom and at the top of the posts 11, receive, after the shock of the block, the essential of the kinetic energy acquired by the stones and must therefore be equipped with energy dissipation mechanism. These mechanisms are provided with a form of energy dissipation loop 20, comprising fuses as mentioned below, and which can be, according to particular embodiments of the invention, loops provided with fuses in parallel or series-mounted loops. A first embodiment of a power dissipation loop 20 is shown in FIG. 3. The loop comprises a carrier cable 3 provided with a first attachment element 31 and a second element of FIG. hooking 32, for connecting, in between, a fuse 40. The attachment elements 30 are intended to be intrinsic elements to the carrier element. The length of the fuse 40 is substantially less than the length of the carrier element between the attachment means 31, 32. This part of the carrier element is indicated with the number 33. When the moving body braking device according to the invention is used, a force is exerted on the carrier element 3. The relative pulling force

  7 to the impact of the moving body, on the carrier element 3, is indicated by an arrow in Figure 3. This pulling force is transmitted by the fuse element 40 between the elements 31 and 32. The fuse element 40 elongates and absorbs a portion of the kinetic energy of the moving body until it breaks, illustrated in FIG. 4.

  It is possible to mount fusible elements in parallel, as shown in Figure 5, or in series, as shown in Figure 6.

  According to the invention, it is provided that between the elements 31 and 32 and the carrier element 3, there is a first fuse 41 and a second fuse 42. This makes it possible to adapt the maximum amount of energy capable of be absorbed by the energy dissipation loop 20 '.

  Figure 7 shows a carrier element 3 'which is in the form of a chain. The fact that the carrier element 3 'has the form of a chain, facilitates the mounting of the fuses 43, 44, 45, 46. The fuses 43-46 are each mounted between two links of the chain 3'. The carrier member 3 'and the fuses 43-46 together form an energy dissipation loop 20 "with four fuses which, one by one, can dissipate a certain amount of energy from a moving body.

  FIG. 8 shows the carrier element 3 'with, between two links, a fuse 50 comprising 3 rings 51, 52, 53 which together form a chain-type fuse between two links of the carrier element.

  The load-bearing elements used in the moving body braking device and used in the dynamic stone fall arrest barrier are generally metal cables, preferably steel, with a diameter of between 10 and 25 mm. Fuses must have a lower yield strength than the load cell. As shown below, the fuses may be metal, steel, or plastic or composite having mechanical parameters equivalent to those of steel, fire-resistant and ultraviolet radiation to which they are constantly exposed.

  In fact, all materials capable of absorbing some energy can be used as fuses. It should be noted that the fuses can be reused. This means that the fuse, for example rubber, undergoes an elastic deformation to slow the moving body. After using the device according to the invention, it is possible for the fuses to return to their initial position and be ready for a new use of the braking device of the moving body.

  In the present text, reference is made particularly to barriers to protection against falling rocks. It is important to note that the device according to the invention can also be used in the following non-exhaustive examples in air, on land, on and in water, for braking a moving body, by example a rock, a rolling machine, flying or floating or a living being.

  In FIG. 9, there is shown a thread 50 provided with a plurality of fuses 51. In FIG. 9, only part of the thread 50 is shown.

  The fuses 51 are fixed in the mesh of the net 50. They are mounted in such a way that the mesh of the net 50, in a position of the net at rest, is substantially lower than the mesh of the net in the case where the fuses do not exist. .

In Fig. 10, the net 50, according to Fig. 9, is shown after the impact of a moving body. Fig. 10 again shows the net with a much larger mesh size than that shown in Fig. 9. The fuses 51 were broken and, upon breaking, absorbed energy to slow the moving body. According to the invention, the fuses 51 of the net 50 may be in the form of a loop, the fuse being, for example, a certain length of cable, formed in a loop and placed in the mesh of the net. Such fuses can be put into the net, in situ, without the need to be transported to the workshop and thus prepared the net for future use.

According to Fig. 10, the fuses 51 are scattered in the mesh of the net 50 irregularly. The fuses can be arranged in any way depending on the use of the net 50.

Claims (6)

  1. Device for braking a moving body comprising at least one element for braking said moving body, characterized in that said element for braking said body comprises a net, said net being provided with energy dissipation means comprising at least one fuse.   2. Device for braking a moving body according to claim 1, characterized in that said fuse has the shape of a loop.   3. Device for braking a moving body according to claim 1 or 2, characterized in that said fuse is a cable.   4. Device for braking a moving body according to one of claims 1 to 3, characterized in that said fuse is fixed in the mesh of the net.   5. Device for braking a moving body according to one of claims 1 to 4, characterized in that said fuse is mounted so that the mesh of the net, in a position of the net at rest, is substantially lower than mesh of the net in the case where said fuse does not exist.   6. Device for braking a moving body according to one of claims 1 to 5, characterized in that said net is provided with energy dissipation means comprising a plurality of fuses, said fuses being dispersed in the mesh. the net, irregularly.