Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
  • E01F7/00—Devices affording protection against snow, sand drifts, side-wind effects, snowslides, avalanches or falling rocks; Anti-dazzle arrangements ; Sight-screens for roads, e.g. to mask accident site
  • E01F7/04—Devices affording protection against snowslides, avalanches or falling rocks, e.g. avalanche preventing structures, galleries
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
  • F16G11/00—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes
  • F16G11/04—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes with wedging action, e.g. friction clamps
  • F16G11/044—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes with wedging action, e.g. friction clamps friction clamps deforming the cable, wire, rope or cord
  • F16G11/046—Means for fastening cables or ropes to one another or to other objects; Caps or sleeves for fixing on cables or ropes with wedging action, e.g. friction clamps friction clamps deforming the cable, wire, rope or cord by bending the cable around a surface

Definitions

• the present invention finds application in the most different fields of use of either metallic or non-metallic ropes, and more particularly it refers to a braking device with friction rope and plastic deformation dissipation devices.
• Ropes, cables, cords are all synonyms for indicating flexible connection means having a length greater than their cross-section diameter and capable of transmitting tensile forces only.
• Metallic ropes are usually employed in the manufacturing and setup of anti-rockfall or snow-retaining elastic barriers, in the making of suspended bridges and tensostructures, in the suspension of loads handled by lifting equipment (cranes, elevators), anchor devices according to UNI EN 795 etc.; a further important field of application for ropes is the free climbing on rocks.
• Braking devices are known from prior art, belonging to two different categories, the first of which exploits the friction generated by a rope constrained within a tortuous path, whereas the second one exploits the friction generated within a ductile metal element (plastic deformation) connected in series to the rope.
• Figure 1 shows a braking device falling within the first category, in a "rest" configuration.
• Figure 2 shows a working configuration taken by the same device immediately after a threshold tension is exceeded.
• Figure 3 shows the final configuration taken by the device. Though known, the device of Figure 1 is hereinafter illustrated in detail because it is a component of the invention to be described.
• Figure 1 there can be seen a length of rope 1 bent back on itself at one of its ends so as to form a load-hooking loop 2 secured by a sleeve 3.
• the loop 2 lies in the groove of a thimble 4 that prevents wear thereof by improving load distribution.
• the rope 1 passes through a sequence of drilled holes 5 provided in a metallic plate 6.
• the holes 5 are arranged in a straight line, but in other embodiments they can be offset, and their edges are preferably countersunk in order to prevent wear of the rope 1.
• a last hole 5b is not passed through by the rope 1, but it serves only for the passage of suitable means for anchoring the drilled plate 6 to a point fixed relative to the rope 1, e.g. a rock wall.
• the end of the rope 1 opposite to the loop 2 terminates in a sleeve 7 having oval or circular cross-section.
• the rope 1 upon passing through the drilled plate 6 takes a serpentine configuration.
• the rope section comprised between sleeve 7 and plate 6 is shown as parallel to plate 6, whereas it is actually freely hanging.
• the length of the rope 1, the number of the holes 5 and the number of the rows of holes provided in the plate 6 are parameters that can increase depending on the kinetic energy to be dissipated into heat by friction.
• the arrow on the loop 2 in Figures 2 and 3 indicates the direction of sliding of the rope 1 in the hole 5, corresponding to the direction of movement of the load (not shown).
• the two arrows of opposite directions tension the section of rope 1 comprised between the loop 2 and the distal hole 5, while the remaining rope section is not tensioned.
• the movement stops when all the kinetic energy of the load has been dissipated by friction, preferably before the limit stop sleeve 7, if existing, abuts against the edge of the plate 6 or the rope 1 pulls out of the plate 6.
• a drawback of the braking device just described is that it must be dimensioned for the worst event, so as to prevent damaging of the anchorages, but this involves using oversized devices in the presence of ordinary loads.
• Figure 4 shows a braking device of the second category, using an unelastic "spring” 8 in series with two rope sections 9 and 10 of different length. These rope sections are connected to the spring 8 by means of corresponding connectors 11 and 12 arranged on opposite sides.
• the longer section 9 ends with an eyelet 13 for hooking the load; the shorter section 10 ends with an eyelet 14 for hooking on a fixed anchor point.
• the two eyelets 13 and 14 are similar to the loop 2.
• the spring 8 is in its rest configuration, whereas in Figure 5 it is irreversibly elongated by a certain length.
• both rope sections 9 and 10 are tensioned in Figure 5.
• Figures 6 and 7 correspond to Figures 4 and 5 but for the fact that the unelastic spring 8 is replaced with a ductile metal cylinder 15.
• the main drawbacks of the dissipation devices of the second category shown in Figures 4 to 7 are the following: 1) because of the deformation irreversibility it is necessary to substitute the dissipation device that has worked; 2) the parts connecting the ductile element to the rope sections tend to more easily become detached; 3) the yield point may exceed the breaking point thus cancelling the advantages of the use of the device.
• An object of the present invention is to overcome the drawbacks of both categories of known dissipation devices without sacrificing use thereof.
• a braking devices including:
• said device further includes:
• tubular element crossed axially by the rope section, said tubular element being made of metal material subject to plastic deformation caused by the compression of the element itself against said drilled plate when the rope is put under tension by the load.
• the tubular element consists of a metal body which can be slidable relative to the corresponding rope section or fixed thereto.
• tubular element consists of a coating layer of the corresponding rope section.
• the tubular element irrespective of how it is applied, is subject to plastic deformation caused by compression of the element itself against said drilled plate.
• the braking device further includes two opposite square washers located at the two ends of the tubular element in order to promote contrast against the drilled plate and the limit stop means, where existing.
• the drilled plate has an additional hole for connection to anchor means.
• the coating layer is made in a color contrasting with that of the drilled plate for allowing to visually perceive the working condition or rest condition of the device.
• the braking device according to the invention can be advantageously applied to the field of protective barriers against falling rocks, snow-slides, as well as in all those applications where a surplus of efficacy and safety is required with respect to known dissipation devices.
• FIG. 1 to 3 show in sequence the configurations taken by a braking device with friction rope of conventional type
• FIG. 8 is a plan view of a braking device according to the present invention.
• FIG. 11 and 12 are enlarged views of a drilled plate that can be seen in the previous Figures 8 and 9;
• FIG. 13 is a front view of a counter-plate that is visible from one side in Figure 8;
• FIG. 14 and 15 show in sequence the configurations taken by the braking device of Figure 8 during and at the end of the intervention step.
• Figure 8 shows a braking device consisting of two parts having a rope 1 in common.
• the first part is the friction rope dissipation device described in Figure 1, the components of which are here indicated with the same reference numerals;
• the second part comprises a tubular element 18 having a circular cross-section and axially bored for being passed through from one end to the other by the rope section 1 ending in the limit stop sleeve 7 secured to the rope 1 at end of the rope 1 opposite to that connectable to a load.
• two identical square washers 19 and 20, which are as well passed through by the rope 1 are located opposite to each other at the two ends of the tubular element 18 in order to abut against the drilled plate 6 and the sleeve 7, respectively.
• the rope 1 is made of zinc plated steel or stainless steel with an outer diameter depending on the yield strength specific for its intended use.
• the drilled plate 6 is made of zinc plated steel or stainless steel.
• the sleeves 3 and 7 are for instance made of an aluminum alloy or other material.
• the tubular element 18 is for instance made of an aluminum alloy or other material subject to plastic deformation.
• the abutment washers 19 and 20 are made of steel.
• the loop 2 includes a metal thimble 4.
• the configuration of Figure 8 is the "rest" configuration of both dissipation devices, characterized by the minimum length of the rope section 1 between the loop 2 and the plate 6, thus leaving the tubular element 18 free to slide along the rope section passing through it.
• the difference between the length of this rope section and the length of the tubular element 18 allows to gradually vary the delay of intervention of the second dissipation device (working by deformation) with respect to the intervention of the first dissipation device (working by friction).
• Several strategies are possible, but, considering that the tubular element 18 needs to be replaced after it has worked, it would be more convenient to let the rope 1 work for some time inside the plate 6 before making the second dissipation device constituted by the tubular element 18 intervene.
• the tubular element 18 can be slidable relative to the rope section 1 that crosses it or it can be fixed to this rope section, for instance by means of welding or compression.
• limit stop means 7 will be necessary for preventing the element 18 from slipping out.
• Limit stop means 7 as well as the possible washer 20 arranged between the tubular element 18 and the limit stop sleeve 7 can instead be avoided in the latter case.
• Figures 9 and 10 are side views, respectively from the left and from the right, of the device of Figure 8 and for their description reference is made to what has already been said regarding Figure 8.
• Figures 11 and 12 are enlarged views of the drilled plate 6 visible in Figures 8 and 9 and for their description reference is made to what has already been said; in particular it can be seen that the edges of the holes 5 are preferably countersunk in order to prevent them from cutting the rope 1.
• Figure 13 is an enlarged view of the abutment washer 20 (identical to 19) viewed in the direction of the tubular element 18. Said washer has a central hole 21 for the passage of the rope 1, its opposite face coming into contact with the edge of the tubular element 18, as indicated by two dashed concentric circles. The same figure would be obtained if viewing the washer 20 in the direction of the sleeve 7 and the same would apply to the washer 19 with respect to the drilled plate 6 and the tubular element 18. The square shape of such washers promotes the abutment action.
• the tubular element 18 consists of a coating layer of the corresponding rope section 1.
• Said coating layer is preferably obtained by applying onto the outer surface of the rope section concerned a plastic material, for instance a thermoplastic resin, which preferably adheres firmly to the rope 1.
• plastic material can be for instance applied onto the rope 1 by spraying.
• the coating layer defining the tubular element 18 may therefore be slidable relative to the rope 1, if not adhering to the rope itself, or it can be fixed to the rope, if firmly adhering to the rope itself.
• the coating layer defining the tubular element 18 further has a thickness of some millimeters, preferably of at least 2 mm and more preferably comprised between 3 and 5 mm.
• the coating layer defining the tubular element 18 may further have a color contrasting with that of the drilled plate 6 in order to allow to visually perceive the working condition or rest condition of the device.
• the coating layer defining the tubular element 18, undergoing a plastic deformation caused by compression against the drilled plate 6 exerted by the limit stop means pulled by the rope may possibly partially penetrate inside the holes 5, thus increasing the friction exerted by the rope in the tortuous path.
• the tubular element 18 formed by the coating layer is less subject to damages before use.
• the braking device of Figure 8 can be applied instead of known devices as shown in Figures 1 to 7.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Braking Arrangements (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (3)

Cited By (5)

Citations (1)

• 2012
  • 2012-05-14 IT IT000432A patent/ITTO20120432A1/it unknown
• 2013
  • 2013-01-15 EP EP13705590.1A patent/EP2872696A1/fr not_active Withdrawn
  • 2013-01-15 WO PCT/IB2013/050367 patent/WO2013171592A1/fr not_active Ceased

Patent Citations (1)

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