Device for braking the fall of a load

Abstract

A device (1) is described for braking the fall of a load comprising a sling (2) and a braking element (3, 30), said sling (2) comprising a first end (21) constrainable to an anchoring point; a second end (22) constrainable to said load; a folded section (23) comprising a first portion (23a) of said sling (2) reversibly joined to a second portion (23b) of said sling (2), said folded section (23) providing a resistance to the separation of said first and second portions (23a, 23b). The sling further comprises a first free section (24) comprised between said first portion (23a) of said folded section (23) and said first end (21); and a second free section (25) comprised between said second portion (23b) of said folded section (23) and said second end (22). The braking element (3, 30) comprises a plurality of passages for said sling (2), said first free section (24) crossing at least one first passage (3a), said second free section (25) crossing at least one second passage (3b), so that said first portion (23a), as a consequence of the application of a traction force (FT, FT) higher than a threshold value to at least one of said two ends (21, 22), separates from said second portion (23b) and crosses said first passage (3a), and said second portion 23b crosses said second passage (3b).

Claims

1. Device (1), comprising a sling (2) and a braking element (3, 30), said sling (2) comprising: a first end (21) constrainable to an anchoring point; a second end (22) constrainable to said load; a folded section (23) comprising a first portion (23a) of said sling (2) reversibly joined to a second portion (23b) of said sling (2), wherein said folded section (23) provides a resistance to separate said first and second portions (23a, 23b); a first free section (24) comprised between said first portion (23a) of said folded section (23) and said first end (21); a second free section (25) comprised between said second portion (23b) of said folded section (23) and said second end (22); and wherein said braking element (3, 30) comprises a plurality of passages for said sling (2), wherein said first free section (24) crosses at least one first passage (3a), wherein said second free section (25) crosses at least one second passage (3b) so that said first portion (23a), as a consequence of apply a traction force (FT, FT) higher than a threshold value to at least one of said two ends (21, 22), separates from said second portion (23b) and crosses said first passage (3a), and said second portion (23b) crosses said second passage (3b).

2. Device (1) according to claim 1, wherein said folded section (23) comprises a plurality of sectors (231, 232, 233, 234, 235, A, B), wherein said portions (23a, 23b) are reversibly joined to one another, preferably said sectors (231, 232, 233, 234, 235, A, B) and provides a resistance to separation different from one another.

3. Device (1) according to claim 1, wherein said portions (23a, 23b) of said folded section (23) are joined to one another by at least one seam (41, 42, 43, 44, 45, 51, 52, 53, 54, 55, 60).

4. Device (1) according to claim 3, wherein said portions (23a, 23b) are joined to one another by a plurality of seams (41, 42, 43, 44, 45, 51, 52, 53, 54, 55), said seams (41, 42, 43, 44, 45, 51, 52, 53, 54, 55) being different from one another.

5. Device (1) according to claim 3, wherein said portions (23a, 23b) are joined to one another by a single seam (60), said seam (60) having variable arrangement as a function of a distance from said braking element (3, 30).

6. Device (1) according to claim 1, wherein said folded section (23) crosses said braking element (3, 30), by means of an intermediate passage (3c), arranged between said at least one first passage (3a) and said at least one second passage (3b).

7. Device (1) according to claim 1, wherein said first free section (24) crosses a number of passages equal to the number of passages that said second free section (25) crosses.

8. Device (1) according to claim 1, wherein said braking element (3, 30) comprises an elongated body (3d) provided with through-openings to define said passages (3a, 3b).

9. Device (1) according to claim 8, wherein thickness of said body (3d) is smaller than the other two dimensions of said body (3d), so that a plate is defined.

10. Device (1) according to claim 1, wherein said braking element (30) comprises two overlapped plates (31, 32) provided with openings (31a, 31b, 31c, 32a, 32b, 32c) to define said passages.

11. Device (1) according to claim 10, wherein an intermediate element (33) is placed between said plates, said intermediate element (33) being in turn provided with openings (33a, 33b, 33c) to define said passages.

12. Device (1) according to claim 1, wherein said braking element (3, 30) comprises a body (3d) provided with said passages (3a, 3b, 3c), and said free sections (24, 25) of said sling (2) cross said body (3d) Alternately Through said passages.

13. Device (1) according to claim 12, wherein said body (3d) has a symmetry plane (P1) dividing said body (3d) in two parts, a first part having said at least one first passage (3a), and said second part having said at least one second passage (3b).

14. Device (1) according to claim 13, wherein said symmetry plane (P1) divides said intermediate passage (3c) in half.

15. Device (1) according to claim 12, wherein said sling (2) crosses said passages (3a) by an angle (a) comprised between +60 and 60 degrees with respect to a plane (P2) perpendicular to the side surfaces (3e, 3f) of the body (3d) of the braking element.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Referring to the accompanying figures, exemplary and not limitative embodiments of the present invention are now presented, wherein:

(2) FIG. 1 is a side sectional view of an embodiment of a device according to the present invention;

(3) FIG. 2 is a perspective view of the device of FIG. 1;

(4) FIG. 3 is an enlarged and cut away view of FIG. 1;

(5) FIG. 4 is a side view of the sling of the device of FIG. 1;

(6) FIGS. 5A and 5B respectively show a side view and a front view of the braking element of the device of FIG. 1;

(7) FIGS. 6A-6C show three possible embodiments of the folded section of a sling of a device of the present invention;

(8) FIG. 7A is a view of a variation of the embodiment of FIG. 1, and FIG. 7B is a magnification of a detail of FIG. 7A;

(9) FIG. 8 is a view of a variation of the embodiment of FIG. 7;

(10) FIGS. 9A-9C show three consecutive steps of use of the device of FIG. 1.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

(11) Referring to figures, a device 1 according to an embodiment of the present invention comprises a sling 2 and a braking element 3.

(12) Referring specifically to FIG. 4, the sling 2 (shown unconstrained from the braking element 3) comprises a first end 21 and a second end 22 opposed to the first end 21.

(13) The first end 21 is constrainable to a support point, for example an anchoring point, preferably static or however little dynamic, whereas the second end 22 is constrainable to a load not shown in figures.

(14) The load can consist for example of a person, which can be constrained to the end 22 of the sling by proper connecting means, such as for example connectors, karabiners, rings and the like suitable to be connected to a harness, or a belt of the person.

(15) According to a possible embodiment, the ends 21, 22 comprise a portion 21a, 22a preferably folded and joined in known manner to the sling 2, so as to preferably form eyelets 21b, 22b which can serve as latch for an outer connecting element.

(16) Between the two ends 21, 22, the sling 2 comprises a folded section 23. More specifically the folded section 23 is formed by two portions 23a, 23b of the sling 2 reversibly joined to one another.

(17) As better explained in the following, the first portion 23a and the second portion 23b are joined to one another and have a given resistance to the separation.

(18) In other terms, when a force is applied to the sling 2, and in particular a traction force FT which tends to move away the ends 21, 22 from one another, the resistance to the separation of the portions 23a and 23b of the folded section 23 counters such a traction force FT.

(19) As above mentioned, such a force FT applied to the sling 2 is reduced when it reaches the folded section due to the amplified braking generated by the combined and synergistic action of the mentioned resistance to the separation of the portions 23a and 23b and the friction coefficient of the braking element.

(20) If such a reduced traction force FR, applied to the sling 2 at the portions 23a, 23b, is smaller than the resistance to the separation of the same portions 23a and 23b, these remain joined to one another. If, on the contrary, the reduced traction force FR is larger than the resistance to the separation of the portions 23a and 23b, these separate and allow the ends 21, 22 of the sling 2 moving away from one another.

(21) Between the first portion 23a of the folded section 23 and the first end 21, the sling 2 has a first free portion 24. Such a portion is called free since it is not constrained to other portions of the sling 2.

(22) Similarly, a second free portion 25 is arranged between the second portion 23b of the folded section 23 and the second end 22 of the sling 2.

(23) Referring specifically to FIGS. 6A-6C, possible methods for joining the portions 23a and 23b of the folded portion 23 are now discussed.

(24) In particular, in FIGS. 6A-6C, the portions 23a and 23b are joined by means of seams. The seams are arranged so as to form sectors 231, 232, 233, 234, 235, A, B of the folded section 23, which have resistances to the separation of the portions 23a, 23b different from one another.

(25) Typically, the sectors 231, 232, 233, 234, 235, A, B provide resistance to the separation of the portions 23a, 23b increasing as a function of the distance from the braking element 3 (or however from the ends 21, 22 of the sling 2), such that the progressive separation of the sectors 231, 232, 233, 234, 235, A, B requires preferably increasing energy.

(26) More specifically, in the embodiment shown in FIG. 6A each sector 231, 232, 233, 234, 235 has a set of seams 41, 42, 43, 44, 45.

(27) The seams of a sector are different from the seams of at least another sector. In particular, according to a possible embodiment such as for example shown in the accompanying figures, the sets of seams 41, 42, 43, 44, 45 are arranged with different density inside the respective sector 231, 232, 233, 234, 235.

(28) In an alternative embodiment, for example as shown in FIG. 6B, each sector 231, 232, 233, 234, 235 comprises a single seam 51, 52, 53, 54, 55 but arranged so as to differently occupy the space in each sector 231, 232, 233, 234, 235. More in detail, the seam of a sector occupies a surface different from the surface occupied by a seam of another sector.

(29) In an additional alternative embodiment, for example shown in FIG. 6C, the portions 23a, 23b are joined by a single seam 60.

(30) The seam 60 varies its own arrangement as a function of the distance from the braking element 3. In particular, the seam 60 has a pattern that becomes increasingly thick as the distance from the braking element 3 increases.

(31) Differently from the previous implementations, sectors separated from one another are not sharply detectable. Generally, taking into account two sectors A, B having coincident size, randomly selected and placed at different distances from the braking element 3, such sectors A and B have resistances to the separation of the portions 23a, 23b different from one another.

(32) The three shown embodiments are to be considered as three possible solutions in order to achieve a variable resistance to the separation of the portions 23a, 23b. Other arrangements, not shown, are possible, such as for example the implementation of seams having different shape and density, with both increasing and decreasing resistance of the seams. As an additional example, the portions 23a, 23b could be joined to one another by means of adhesion by gluing or by means of micro hooks, for example of Velcro type.

(33) Furthermore, according to some possible embodiments the portions 23a, 23b are joined to one another with constant resistance to the separation as a function of the distance from the braking element 3, or however of the distance from the ends 21, 22. In other words, in alternative embodiments not shown, the folded section 23 comprises a single sector.

(34) The device 1 further comprises a braking element 3 adapted to be engaged with the sling 2, such that the friction caused by the sling 2 sliding and contacting the braking element 3 interferes with the same sliding.

(35) In particular, the braking element 3 (which can be seen in detail in FIGS. 5A and 5B) is provided with a plurality of passages 3a, 3b for the sling 2.

(36) Referring specifically to FIG. 3, the sling 2 is inserted inside the passages 3a, 3b such that the first free section 24 crosses a first set of passages 3a, and the second free section 25 crosses a second set of passages 3b.

(37) Each set of passages 3a, 3b comprises one or, preferably, several passages 3a, 3b. In the embodiment shown, the sets of passages 3a, 3b have a number of passages equal to one another. However embodiments wherein the sets of passages 3a, 3b, each set being intended for one of the free portions 24, 25 of the sling 2, have a number of passages different from one another, can be provided.

(38) Preferably, the folded section 23 is in turn inserted inside an intermediate passage 3c. Generally, the sling 2 is inserted inside the passages 3a, 3b (and possibly 3c) such that the friction caused by the contact between the sling 2 and the braking element 3 counters a traction force FT applied to the two ends 21, 22 of the sling 2.

(39) In the embodiment shown in the figures, the braking element 3 has a body 3d provided with openings adapted to define the passages 3a, 3b (and possibly the intermediate passage 3c) and the sling 2 is inserted inside such openings such that the free portions 24, 25 cross the body 3d of the braking element 3 alternately.

(40) In other words, by considering the braking element 3 in planar view, the free portions 24, 25 are alternately arranged, above and underneath the body 3d of the braking element.

(41) Typically, the passages 3a, 3b and thus the openings for the sling passage, are defined by a set of pegs 3g, or similar elements, defining at least part of the edges of the passages (openings) 3a, 3b. According to a possible embodiment shown in FIGS. 1-5, the pegs are aligned to one another. In other words, the braking element 3 typically has a set of pegs 3g arranged in series and at a distance from one another. The space between consecutive pegs defines the mentioned passages.

(42) When a free portion 24 or 25 crosses a passage 3a or 3b, this portion crosses the body 3d of the braking element from a first side surface 3e to a second side surface 3f. On the contrary at the subsequent passage 3a or 3b, the free portion 24 or 25 crosses the body 3d of the braking element 3 in opposite direction, i.e. from the second surface 3f to the first surface 3e.

(43) In other words, the body 3d has two side surfaces 3e, 3f opposed to one another. It has to be noted that in the accompanying FIGS. 3, 5A, the side surfaces 3e, 3f of the body 3d have been schematically illustrated by two dashed lines.

(44) The passages 3a, 3b cross the body 3 from the first side surface 3e to the second side surface 3f. Preferably, the sling 2 crosses the openings 3a, 3b by an angle between +60 and 60 degrees, measured with respect to a plane P2 perpendicular to the side surfaces 3e, 3f of the body 3d. As mentioned, the sign of the angle (i.e. the evaluation which determines if the angle is positive or negative) is a function of the course of the sling inside the respective passage. Typically, the sling orientation depends on the distance between two consecutive pegs. If the distance D is larger than the sling thickness (as in FIG. 3) the angle is generally positive. On the contrary if, as in FIG. 7B, the distance is smaller than the sling thickness (in that case the distance is substantially equal to zero), the angle is generally negative.

(45) Furthermore, the braking element 3 has an opening adapted to define an intermediate passage 3c, in order to allow the insertion of the folded section 23 of the sling 2 through the braking element 3.

(46) The openings of the braking element, in the embodiment shown, are substantially identical to one another but could also exhibit different shapes; furthermore, in the shown figure, the openings are equally spaced from one another, although embodiments wherein the distance among the various openings is not constant, i.e. it varies among different subsequent pairs of openings, are not excluded.

(47) In the embodiment of the figures, the braking element 3 is provided with a symmetry plane P1, which divides the passages 3a from the second passages 3b intended for the first and second free sections 24 and 25, respectively.

(48) In case there is an intermediate passage 3c in order to allow the folded section 23 crossing the braking element 3, the symmetry plane P1 cuts such an intermediate passage. According to a possible embodiment, as for example visible in FIGS. 1-6, the braking element has an elongated body with reduced thickness with respect to its own other dimensions. In other words, the braking element is plate shaped.

(49) In an alternative embodiment, for example shown in FIGS. 7A and 7B, the braking element 30 comprises two plates 31, 32 positioned side by side and provided with openings 31a, 31b, 31c, 32a, 32b, 32c facing one another so as to implement the mentioned passages for the sling 2.

(50) The openings of the two plates 31, 32 are offset from one another, in order to fold the sling 2 so as to reverse the forward direction of the sling with respect to the development of the braking element 30 in longitudinal direction. Thus, preferably the angle (shown in FIG. 7B) takes null or negative values, preferably comprised between 0 and 60 degrees.

(51) Typically, according to a possible embodiment, the two plates 31, 32 have pegs 31g, 32g arranged so as to form openings 31a, 32a offset from one another, such that a peg 31g of the first plate 31 is facing a corresponding opening 32a of the second plate 32.

(52) At least one intermediate element 33 is interposed between the plates 31, 32. Such an intermediate element is in turn provided with openings 33a, 33b, 33c for the sling 2.

(53) Such an intermediate element can be used for spacing the plates 31, 32 apart and allowing a more effective dispersion of the heat generated by the friction of the sling 2 on the braking plates 31, 32, during the fall. For example, the plates 31, 32 can be made of metal in order to ensure the required sturdiness of the braking element, whereas the intermediate element 33 can be made of plastic, for the afore mentioned purposes. In alternative embodiments, not shown, the intermediate element can be missing. In alternative embodiments, not shown, the braking plates 31, 32 and the intermediate element 33 can be made in a single piece.

(54) Furthermore, in an alternative embodiment a single plate 34 can have passages 34a, 34a, 34b, 34b, 34c offset from one another, so as to form a pathway for the sling 2 similar to that of the embodiment of FIG. 7. More specifically, the first set of passages 34a, 34a is implemented by means of pegs 35a, 35a which are alternatively arranged along two parallel planes. Similarly, the second set of passages 34b, 34b is implemented by means of pegs 35b, 35b which are alternatively arranged along two parallel planes (preferably coincident to the two planes along which the pegs 35a, 35a forming the first set of passages 34a, 34a are alternately arranged).

(55) Generally, the sling 2 is inserted within the passages 3a, 3b of the braking element 3 such that, when a traction force FT higher than a threshold value is applied, i.e. a force FT such that the respective reduced force FR is enough to separate the portions 23a, 23b, the first portion 23a slides inside the first set of passages (or the passage) 3a and, similarly, the second portion 23b slides inside the second set of passages 3b.

(56) The force FT is equal to the threshold value when the respective reduced force is equal to the resistance to the separation of the portions 23a, 23b of the sling.

(57) As mentioned, thanks to the present invention the braking effect of the friction between the sling 2 and the braking element 3 can be amplified so as to generate a synergistic effect of the resistance to the separation of the sling folded portion, provided for example by the at least one seam, and the friction generated during the sliding of the sling inside the braking element 3.

(58) The experiments carried out during the development of the invention highlighted that, for example, a sling with sectors 231, 232, 233, 234, 235 with seams that can be teared at about 0.65 kN, 0.9 kN, 1.5 kN and 1.8 kN, the sling being combined with a braking element able to develop under normal conditions (i.e. with the simple sliding of a sling with the folded portion 23 free from seams, gluing or other elements, able to resist to friction forces equal to about 0.25 kN), is able to develop amplified braking forces respectively of about 3.5 kN, 4.5 kN, 5.5 kN and 6 kN.

(59) Referring specifically to FIGS. 9A-9C in use, in idle condition the device 1 is arranged as in FIG. 9A.

(60) More in detail, the free portions 24, 25 of the sling 2 contact the braking element 3, and the folded section 23 has the portions 23a, 23b joined to one another.

(61) Then, the fall of the load, such as for example a person, applies a traction force FT on the end 21 of the sling 2. Similarly, the support point applies a traction FT to the other end 22 of the sling 2.

(62) To simplify the description, it is shown an embodiment wherein the folded section 23 is provided with two sectors A,A and B,B with resistances to the separation different from one another. The following description applies mutatis mutandis also to embodiments with a different number of sectors (also a single sector).

(63) The free portions 24, 25 slide inside the passages 3a, 3b of the braking element until the sector A, A reaches the braking element 3. Simultaneously, the friction generated by the sliding of the free portions 24, 25 against the braking element 3 brakes the movement of the same free portions. When the sector A, A reaches the braking element 3, the braking action is generated by the combined, synergistic and amplified action of the mentioned resistance to the separation of the portions 23a and 23b and the friction of the braking element 3.

(64) Then, if the reduced force FR coming to the folded section 23 is lower than the value of the resistance to the separation of the sector A, A, i.e. in case the force FT is lower than the mentioned threshold value, the folded section 23 remains intact and the device 1 interrupts the movement of the sling 2.

(65) If the force FT is higher than the threshold value, and thus the reduced force FR is higher than the resistance to the separation of the sector A, A, the portions 23a, 23b separate at such a sector. Such a condition is shown in FIG. 9B. The sector A, A thus separates such that the portions 23a, 23b are each partially inserted in a set of passages 3a, 3b of the braking element.

(66) In detail, the first portion 23a crosses the first set of passages 3a, while the second portion 23b crosses the second set of passages 3b.

(67) The resistance of the sector A, A, which provides a resistance to the separation, causes a variation in the strain state of the portions 24, 25 whereby, given the friction coefficient between the same sling and the braking element 3, the braking action of the device 1 is remarkably amplified and counters the traction force FT.

(68) The point of separation of the portions 23a and 23b, i.e. the point wherein the two portions 23a, 23b of the folded section 23 separate typically by breakage of the respective seam (or seams), is preferably placed at the intermediate passage 3c. More generally, such a separation point is generally placed substantially at the braking element 3.

(69) Then, if the reduced force FR is lower than the value of the resistance to the separation of the sector B, B, such a sector remains intact and the device 1 interrupts the movement of the sling 2.

(70) Alternatively, if the reduced force FR is on the contrary higher than the resistance to the separation of the sector B, B, the portions 23a, 23b separate completely and cross the braking element, as shown in FIG. 9C.

(71) In particular, in the embodiment shown, the entire folded section crosses the braking body 3 from a first side surface 3e to a second side surface 3f, through the intermediate passage 3c.

(72) It has been therefore highlighted how the device 1 generates, when subjected to a traction force FT applied to the two ends 21, 22, an opposition force given by the combined and synergistic action of a resistance to the separation, which is given by the joined portions 23a, 23b and the friction coefficient between the sling 2 and the braking element 3.

(73) Such a synergy provides an effect of amplification of the resistance to the separation of the joined portions 23a, 23b, which allows to produce absorbers which are particularly effective, conveniently adjustable, gradual and regular during the braking event, especially in case they have to operate for dissipating the energy generated by falls of loads or people with significantly different weight. The effect further allows to produce absorbers which are less complex and mostly limited in size and weight.