Rope access device

Abstract

The invention provides a rope access device for moving along a rope (20) comprising a frame having (12), in use, a first region (12a) facing a portion of the rope under tension (20a), an adhesion pulley (14) mounted on said frame (12) and comprising at its periphery a groove (22) allowing the rope (20) to be pulled by adhesion, the adhesion pulley being coupled to rotational drive means fixed to the frame, a guide pulley (16) located near said adhesion pulley (14), the guide pulley being capable of guiding the rope (20) under tension in the groove (22) of said adhesion pulley (14); and a tightening pulley (18) exerting pressure on the rope (20) in the direction of said adhesion pulley (14) on the side of the slack strand (20b).The guide pulley (16) and the tightening pulley (18) are arranged close to each other in the first frame region (12a) so as to wind the rope (20) around the adhesion pulley (14) over at least half of the circumference thereof, and the lifting rope (20) exits from the adhesion pulley (14) on the first frame region (12a) side.

Description

Technical Field

[0001] The present invention relates to a rope access device for moving along a rope, and in particular to a rope access device to which a user can anchor himself to ascend and descend along a rope. State of the Art

[0002] The invention relates to the field of rope access devices and in particular to rope access devices comprising an adhesion pulley. Rope access devices with an adhesion pulley should not be confused with rope access devices with a drum or the like. Indeed, rope access devices with an adhesion pulley have the characteristic of being able to be used with ropes of unlimited length due to the principle of retention by adhesion of the rope inside a single groove of the adhesion pulley in which the rope is wound over less than one turn.

[0003] Such rope access devices have been developed for professional, safety and sporting uses: access to building facades, wind turbine or boat masts, work areas in elevator shafts, silos, mountain rescue, etc. They have the following advantages over other rope access devices: no height limit can move along the rope and therefore accompany the load.

[0004] These rope access devices can have up to three functions: a locking function, which allows the rope access technician to position themselves and be held on the rope in a desired position, an ascent function, which allows the rope access technician to ascend vertically along the rope, and / or a descent function, which allows the rope access technician to descend along the rope at a speed automatically controlled by the device until a desired position is reached.

[0005] Currently, few rope access devices are capable of performing all three of these functions without direct rope manipulation by the user. Furthermore, these rope access devices are generally bulky and therefore poorly suited for use as a stand-alone portable unit, attached directly to the rope access technician's harness. Subject of the invention

[0006] An object of the present invention is to provide a highly compact rope access device capable of the three functions of blocking, ascent and descent. General description of the invention

[0007] The present invention provides a rope access device according to claim 1, for moving along a rope. It comprises a frame having, in use, a first region facing a portion of the rope under tension, an adhesion pulley mounted on said frame and comprising at its periphery a groove allowing the rope to be pulled by adhesion, the adhesion pulley being coupled to rotational drive means fixed to the frame, a guide pulley located near said adhesion pulley, the guide pulley being capable of guiding the rope under tension in the groove of said adhesion pulley, and a tightening pulley exerting pressure on the rope in the direction of said adhesion pulley on the slack strand side.

[0008] According to the invention, the guide pulley and the clamping pulley are arranged close to each other in the first region of the frame so as to wind the rope around the adhesion pulley over at least half of the circumference thereof, and the rope exits the adhesion pulley from the side of the first region of the frame.

[0009] Further, the clamping pulley is configured to clamp the rope at the bottom of the grip pulley groove and eject the slack strand out of the grip pulley groove.

[0010] By winding the rope around the traction pulley over at least half of its circumference, and by moving the rope in and out from the side of the first region of the frame, the design according to the invention ensures that the rope remains at the bottom of the groove of the traction pulley over a sufficient winding length to guarantee traction. In addition, the fact that the rope always surrounds the part of the traction pulley included in a second region of the frame, thanks to the tightening and guiding pulleys arranged in the first region of the frame, is favorable in terms of safety. It should also be noted that the system is very simple, requiring only 3 pulleys.

[0011] The design of the rope access device is thus simple, compact, secure and can be used as a stand-alone portable unit.

[0012] The rope access device advantageously covers the three functions of blocking, ascent and descent. It allows the user to lock onto the rope to ascend and descend at a controlled speed, moreover it can be motorized which reduces the physical effort to reach the working position. The rope access device does not require manual action to extract the rope from the grip pulley. The rope access technician therefore has one hand free in all circumstances, the other hand being able to, among other things, control the ascent or descent speed thanks to a control device.

[0013] The rope access device allows ascent and descent along a rope of unlimited length. The traction pulley comprises a single groove in which the rope is wound through less than one turn (i.e. less than 360°).

[0014] It will be appreciated that the design of the rope access device has been designed for so-called semi-static ropes of approximately 8 to 12 mm, in particular 10 to 11 mm, in diameter, which results in the integration of a tightening pulley which also provides an extraction function, ejecting the rope outwards and eliminating the tendency for the slack strand to jam or to be manually extracted.

[0015] Furthermore, the design of the rope access device according to the invention, which employs a clamping pulley, also provides an extraction function because it forces the rope to remain at the bottom of the groove of the adhesion pulley until it has been deflected by an extraction finger, and then ejects it from the frame. The clamping pulley ensures that the rope is locked in the adhesion pulley when there is no drive, thus eliminating the need for a specific locking member. The combination of the two functions of clamping and extraction of the pulley also allows a significant winding angle of up to approximately 340° of the rope on the adhesion pulley, which increases the lifting force.

[0016] For its drive, the traction pulley is preferably mounted on a shaft coupled to a manual or motor-driven mechanism, generally via a reduction gearbox. The motor can be electric or thermal.

[0017] The motor control allows the traction pulley to rotate in both directions of rotation, allowing the user to control the ascent or descent of the rope access device on the rope.

[0018] The design of the rope access device also allows for great compactness, making it suitable for use as a stand-alone portable unit, attached directly to a rope access technician's harness.

[0019] The rope access device advantageously includes an anchor point which will be used to attach a flexible link (strap) to the rope access technician's harness.

[0020] The tightening pulley is retractable, which allows the rope to be wound around the grip pulley on the running part of the rope and not just at the end of the rope.

[0021] The traction pulley is preferably of the V-groove type, traction may be improved by a raised pattern on the sides of the groove. The term V-groove is to be taken in a broad sense, the sides being inclined so that the groove narrows towards the bottom, which need not be V-shaped but may generally be curved or flat.

[0022] In practice, the rope and the traction pulley are chosen accordingly.

[0023] To limit wear on the rope while maintaining the compactness of the rope access device, it is advisable to choose a pulley with a winding diameter of at least 80 mm and aim for a winding coefficient of around 8.

[0024] By winding diameter or radius we mean the internal diameter or radius of the pulley groove.

[0025] In particular, the winding diameter of the adhesion pulley will preferably be determined in relation to the diameter of the rope, so as to obtain a force output η b greater than 85%.

[0026] The force yield η b (in static bending) is calculated using the equation: η b = 1 − 0.59 D d 2 3 Or D is the winding diameter of the traction pulley and d the diameter of the rope.

[0027] So with a rope of 11 or 11.5 mm in diameter, we will use an adhesion pulley with a winding diameter of around 90 to 100 mm, or larger.

[0028] According to variants, the distance between the center of the guide pulley and the center of the adhesion pulley is between 1.6 and 2 times the winding radius of the adhesion pulley.

[0029] According to variants, the adhesion pulley, the guide pulley, and the clamping pulley are arranged so as to define a triangle having an angle of 45 ± 2° at the adhesion pulley, an angle of 58 ± 2° at the guide pulley, and / or an angle of 76 ± 2° at the clamping pulley.

[0030] According to variants, the rope has a diameter between 8.0 and 12.0 mm, in particular 10.0, 10.5, 11.0 or 11.5 mm; and the traction pulley has a winding diameter of at least 8.0, 9.0 or 10.0 cm.

[0031] According to variants, the guide pulley and the tightening pulley are positioned such that the rope is engaged in said groove at an angle of at least 200°, preferably at least 280° and more preferably between 320° and 340°.

[0032] According to variants, said groove is defined by two lateral flanks whose spacing gradually reduces as a function of depth, forming a V-shaped groove, the V-shaped groove preferably having an opening angle of 25 to 35°; and preferably the flanks of the groove have a raised pattern for increased grip, preferably trapezoidal ribs inclined in the direction of the stretched strand.

[0033] According to variants, which the adhesion pulley has a diameter of at least 80 mm and a winding coefficient of the order of 8.

[0034] According to variants, in use the first region is the upper part of the frame, the second region being the lower part.

[0035] According to variants, the rotational drive means comprise a motor coupled via a reducer to a shaft on which said adhesion pulley is mounted.

[0036] According to variants, a control member configured to control said drive means, the control member preferably comprising a joystick capable of remotely controlling said drive means.

[0037] According to variants, a normally closed mechanical service brake is provided at rest.

[0038] According to variants, the adhesion, clamping and guide pulleys are circumscribed to the frame and covered by a first cover; and / or in which the drive means is covered by a second cover, and preferably comprising a handle.

[0039] According to variants, the drive means is an electric motor, and further comprising a battery and a display device capable of displaying a state of charge of the battery.

[0040] These and other embodiments are set forth in the appended dependent claims.

[0041] The term "rope" is to be taken in the broad sense and can include any type of rope made from synthetic, natural, metallic fibers, etc. Brief description of the drawings

[0042] Other features and characteristics of the invention will emerge from the detailed description of an embodiment presented below, by way of illustration, with reference to the appended drawings, in which: Fig. 1 is a front view of the rope access device according to the invention; Fig. 2a and 2b are isometric views of the internal mechanism of the rope access device according to the invention; Fig. 3 is a perspective view of an adhesion pulley; Fig. 4 represents several views of an extraction finger; Fig. 5 is an isometric view of the rope access device according to the invention; Fig. 6 is a view of the rope access device in use; Detailed description using figures

[0043] There Figure 1 shows a front view of one embodiment of the present rope access device 10, the rope (also called a lifting rope or lifting strand) being designated 20. The Figures 2a and 2bshow isometric views of the internal mechanism of said device 10. The device 10 comprises a frame 12 on which is mounted an adhesion pulley 14 (also called a drive pulley) comprising at its periphery a groove 22 (single) allowing the rope 20 to be driven by adhesion, in particular a synthetic rope. For its rotation, the adhesion pulley 14 is fixed to a shaft 19 with which it is rotationally fixed. The frame 12 is here formed by a metal plate (e.g. stainless steel or aluminum) with a thickness of between 8 and 12 mm, a height of 200 mm and a width of 175 mm. The shaft 19 is generally part of a drive means coupled to the adhesion pulley 14 via it, as will be seen below. In the variant as illustrated in Fig. 1, the shaft 19 is housed in a bearing which passes through the thickness of the frame 12, the adhesion pulley therefore being located on the front of the frame, and the drive means being arranged at the rear of the frame, therefore not visible in Fig. 1 .

[0044] On the Figure 1 , the rope access device 10 is shown in its service / use position, in which it can be seen that a taut strand 20a of the rope 20 arrives from the top of the rope access device 10 (the opposite end of the taut strand 20a being fixed to a support - not visible), and that a slack strand 20b is discharged to the side. The taut strand 20a arrives from the side of the upper region of the frame 12a, and the slack strand 20b also exits from the side of the upper region of the frame 12a.

[0045] The notion of upper region is here made in relation to a horizontal plane A, represented on the Figure 1, passing through the center (denoted A 1 ) of the adhesion pulley 14 and the shaft 19: the upper region of the frame 12a is that above the plane A, and the lower region of the frame 12b is that below the plane A. Advantageously, the adhesion pulley 14 is centered with respect to the rope access device 10, i.e. the axis of rotation A 1 of the adhesion pulley 14 passes through the center of gravity of the rope access device 10.

[0046] A single guide pulley 24 is provided to guide the rope 20 under tension from the upper region of the frame 12a to the adhesion pulley 14. The taut strand 20a of the rope 20 arriving from above passes through the guide pulley 24, which ensures the transfer of the taut strand 20a to the adhesion pulley 14. The rope 20 then forms a loop around the adhesion pulley 14 and exits from the latter after a tightening pulley 26 which exerts pressure on the rope 20 towards the bottom of the groove 22. The tightening pulley 26 and the guide pulley 24 are mounted loose.

[0047] The axis of rotation A 3 of the clamping pulley 26 is fixed in use, but this pulley 26 is mounted retractable by means of an arm 28. The arm 28 carries the clamping pulley 26 in a rotatable manner at one end and is itself pivotally fixed in its middle on the frame 12, the pivoting taking place in a plane perpendicular to the shaft 19. A pin 32 makes it possible to limit the movement of the arm 28 to block the clamping pulley 26 near the adhesion pulley 14 when using the device (configuration of the Fig. 1 ). In operation, the clamping pulley 26 therefore normally has a fixed position. The retracted position of the clamping pulley 26 (when the pin 32 is withdrawn and the arm 28 pivoted back) is illustrated in dotted lines on the Figure 1 , and facilitates the installation of the rope 20.

[0048] After the tightening pulley 26, the slack strand 20b of the rope 20 is ejected from the groove 22 of the adhesion pulley 14. Preferably, a first guide 34, called an extraction guide, is placed directly after the tightening pulley 26, defining a curved guide surface 34.1 which cooperates with the tightening pulley 26, so as to accompany the extraction of the slack strand 20b from the groove 22. A curved extraction finger 36 is placed near the first guide 34 and extends from its upper end partially into the groove 22 of the adhesion pulley to facilitate the extraction of the rope 20. Thus, the first guide 34 and the extraction finger allow the extraction of the slack strand 20b from the rope access device 10. It is not useful to ballast the slack strand 20b with a weight to extract it from the adhesion pulley 14.

[0049] A second guide 40 is arranged at the inlet of the guide pulley 24 and defines an insertion channel 41 for the rope 20, the channel defining a straight passage tangential to the guide pulley 24 and extending along an axis C passing through the center A 1 of the adhesion pulley 20. The first and second guides 34, 40 here form a single member consisting of two half-pieces, one mounted on a first cover 44, and the other fixed to the frame 12, so that it is not necessary to thread the rope 20 from one of the rope ends.

[0050] In such a rope access device 10 with an adhesion pulley 14, the traction force depends on the winding angle of the rope 20 in the groove 22 of the adhesion pulley 14 and the adhesion coefficient of the rope 20 in the groove 22, as well as the force exerted by the clamping pulley 26 at the outlet of the adhesion pulley 14. Appropriate dimensioning of the adhesion pulley 14 and the clamping pulley 26, taking into account the service load, therefore allows the production of a rope access device 10 having sufficient lifting force and not requiring an additional brake when stopped.

[0051] To improve the adhesion of the rope 20 in the groove 22, the sides 22.1 of the latter are preferably V-shaped, as shown in the Figures 2a, 2b And 3The grip is further increased by protrusions, here trapezoidal ribs 22.2 inclined in the direction of the taut strand 20 and distributed regularly at the bottom of the groove 22. The orientation of these ribs 22.2 makes it possible to reduce the pressure of the rope 20 at the level of the tightening pulley 26, thus facilitating its extraction.

[0052] The adhesion is further controlled by adequate groove / chord dimensioning, the bottom of the groove 22 having a diameter slightly smaller than that of the chord, e.g. 0.7 to 0.9 times the diameter of the chord, preferably between 0.7 and 0.8. That is to say, the bottom of the groove 22 is not V-shaped, but has a curved or flat bottom. The opening angle of the groove 22 (between the two flanks) can be chosen between 15 and 35°, preferably between 25 and 30°. The thickness of the protrusions can also be adjusted.

[0053] Another parameter affecting the adhesion is the winding angle β at which the rope is engaged in the groove 22 of the adhesion pulley 14. It is the respective positions of the guide pulley 24 and the tightening pulley 26 which determine this winding angle β. The winding angle β is greater than 200°, preferably greater than 270° and in particular between 320 and 359°. As can be seen in the Figure 1, the clamping and guide pulleys are positioned close to each other, separated by the first guide 34, which allows a large winding angle β up to 340°. The various parameters influencing the adhesion will be carefully dimensioned, since they are also factors in the wear of the rope 20. Preferably, a winding coefficient (winding diameter to rope diameter ratio) of the order of 8 will be aimed for, with an adhesion pulley 14 having a winding diameter of at least 80 mm and a semi-static rope of approximately 10 mm in diameter, respectively at least 90 mm for a rope of 11 mm or 11.5 mm. As can be seen from the Figure 1 , the present rope access device 10 is compact, the different pulleys being mounted on the frame in the same plane.

[0054] Preferably, the adhesion pulley 14, the guide pulley 24, and the tightening pulley 26 are arranged so as to define a triangle having an angle α of 45 ± 2° at the level of the adhesion pulley 14, the guide pulley 24 being configured so as to keep the strand 20a taut along the axis C passing through the center of the adhesion pulley A 1 (center of gravity) and the insertion channel 41.

[0055] This optimized configuration ensures good traction of the rope 20 by the adhesion pulley 14 and facilitates its extraction. This configuration also ensures that the rope 20 is neither too tight, which would increase the wear of the rope 20, nor too loose, which would increase the risk of slipping of the rope 20. Simulations have made it possible to estimate a service life for the rope 20 greater than 200-500 cycles.

[0056] In addition, the distance between the center A 1 of the guide pulley 24 and the center A 2 of the adhesion pulley 14 advantageously represents at least 1.6 to 2 times the winding radius of the adhesion pulley 14, thus limiting the forces exerted on the guide pulley 24.

[0057] Figure 5shows an isometric view of the rope access device according to the invention. For user safety, the rope access device 10 comprises a first cover 44 covering the frame 12 and comprising openings for the rope 20. The rope access device 10 also comprises a drive means 46 covered by a second cover (also denoted 46). This drive means comprises a motor coupled at the output to a reduction gear (not shown). The shaft 19 which drives the traction pulley 14 may be part of the reduction gear or be coupled to it. The motor / reduction gear assembly is securely fixed to the frame 12 and covered by the second cover. As is customary in lifting applications, the motor will comprise a service brake, i.e. a mechanical brake normally closed at rest. For an embodiment in the form of a self-contained rope access device, an electric motor with an associated battery may be used.The rope access device 10 may then also include a screen 48 to display at least the battery charge status. This assembly forms a compact, easy-to-use unit, which can be carried by a user by a handle 50.

[0058] The device can advantageously be controlled by means of a control member, for example of the joystick type (not shown), which can be wired or wireless.

[0059] Reference numeral 42 indicates a leg (linked to frame 12) that forms an anchor point or support for an anchor point for receiving a carabiner or other link by which the user can attach a harness, lanyard, or any load. Alternatively, leg 42 may form an anchor point for a rigid frame including a seat, allowing the user to be seated rather than suspended from the rope access device, as shown in FIG. Figure 6. Those skilled in the art may also develop any other solution for forming a structure suspended from, or supported by, this rope access device. Example

[0060] In an exemplary embodiment, for a rope of 11.5 mm diameter and with reference to the configuration of the Fig. 1 the following parameters were determined.

[0061] An adhesion pulley with a winding diameter of 100 mm, which gives a force output η b = 86%.

[0062] The angle α is 45.6°.

[0063] The vertical distance (parallel to axis C) between axis A 2 and the axis of the guide pulley 24 A 2 is 87 mm.

[0064] The vertical distance (parallel to axis C) between axis A and axis A 3 of the clamping pulley 26 is 63 mm.

[0065] This configuration allows operation with a user weighing up to 200 kg.

Claims

1. Rope access device for moving along a rope (20) comprising: a frame having (12), in use, a first region (12a) facing a portion of the rope under tension (20a); an adhesion pulley (14) mounted on said frame (12) and comprising at its periphery a groove (22) allowing the rope (20) to be pulled by adhesion, the adhesion pulley being coupled to rotational drive means fixed to the frame; a guide pulley (16) located near said adhesion pulley (14), the guide pulley being capable of guiding the rope (20) under tension in the groove (22) of said adhesion pulley (14); and a tightening pulley (18) exerting pressure on the rope (20) in the direction of said adhesion pulley (14) on the side of the slack strand (20b); characterized in thatthe guide pulley (16) and the clamping pulley (18) are arranged close to each other in the first region of the frame (12a) so as to wind the rope (20) around the adhesion pulley (14) over at least half of the circumference thereof; wherein the rope (20) exits the adhesion pulley (14) from the side of the first region of the frame (12a); and wherein the clamping pulley (26) is configured to clamp the rope at the bottom of the groove (22) of the adhesion pulley (14) and eject the slack strand out of the groove (22) of the adhesion pulley (14).

2. A rope access device according to claim 1, further comprising an anchor point (42) for a flexible link or a rigid structure, capable of supporting a user or a load, said anchor point (42) being linked to the frame (12) in a second region (12b) thereof.

3. Rope access device according to claim 1 or 2, comprising an extraction means (36), arranged in the first region of the frame (12a) between the clamping pulley (26) and the guide pulley (24) so ​​as to extract the rope (20) from the groove (22) of the adhesion pulley (14); the extraction means (36) preferably comprising an extraction finger (36) extending into the groove (22) of the adhesion pulley (14).

4. Rope access device according to any one of the preceding claims, comprising an extraction guide (34) arranged between the guide pulley (24) and the clamping pulley (26), said first guide (34) defining a curved guide surface which cooperates with the clamping pulley (26), so as to accompany the extraction of the slack strand (20b).

5. Rope access device according to any one of the preceding claims, comprising an entry guide (40) arranged at the entry of the guide pulley (24) and defining a rope insertion channel (20), the channel being tangential to the guide pulley (24) and extending along an axis passing through the center of the adhesion pulley (20), the entry guide (40) and the extraction guide preferably being formed (34) in a single piece.

6. Rope access device according to any one of the preceding claims, wherein said clamping pulley (26) is retractably mounted on a pivoting arm (28) relative to said frame (12), cooperating with a locking means (32) to lock this arm (28) in a position of use; wherein in the position of use, the clamping pulley (26) clamps the rope (20) at the bottom of the groove (22) of the adhesion pulley (14), and wherein in a retracted position, the clamping pulley (26) is set back to allow the rope (20) to be put in place or released.

7. A rope access device according to any preceding claim, wherein the axis of rotation of the traction pulley passes through the center of gravity of the rope access device.

8. Rope access device according to any one of the preceding claims, wherein the distance between the center (A1) of the guide pulley (24) and the center (A2) of the adhesion pulley (14) represents between 1.6 and 2 times the winding radius of the adhesion pulley (14).

9. A rope access device according to any preceding claim, wherein the grip pulley, the guide pulley, and the clamping pulley are arranged to define a triangle having an angle of 45 ± 2° at the grip pulley, an angle of 58 ± 2° at the guide pulley, and / or an angle of 76 ± 2° at the clamping pulley.

10. A rope access device according to any preceding claim, wherein the device has a force output or b greater than 85% meeting the formula η b = 1 − 0.59 D d 2 3 Or D is the winding diameter of the traction pulley andd the diameter of the rope.

11. Rope access device according to any one of the preceding claims, wherein the rope has a diameter between 8.0 to 12.0 mm, in particular 10.0, 10.5, 11.0 or 11.5 mm; and the adhesion pulley has a winding diameter of at least 8.0, 9.0 or 10.0 cm; and / or wherein said guide pulley (24) and said clamping pulley (26) are positioned such that the rope (20) is engaged in said groove (22) over an angle of at least 200°, preferably at least 280° and more preferably between 320° and 340°.

12. Rope access device according to any one of the preceding claims, wherein said groove (22) is defined by two lateral flanks (22.1) whose spacing gradually reduces as a function of depth, forming a V-shaped groove, the V-shaped groove preferably having an opening angle of 25 to 35°; and preferably the flanks of the groove (22.1) have a relief pattern for increased grip, preferably trapezoidal ribs (22.2) inclined in the direction of the taut strand (20a).

13. Rope access device according to any one of the preceding claims, in which the adhesion pulley (14) has a diameter of at least 80 mm and a winding coefficient of the order of 8.

14. Rope access device according to the preceding claim, in which the rotational drive means (46) comprise a motor coupled via a reducer to a shaft (19) on which said adhesion pulley (14) is mounted.

15. Rope access device according to any one of the preceding claims, wherein the adhesion (14), clamping (26) and guide (24) pulleys are circumscribed to the frame (12) and covered by a first cover (44); and / or wherein the drive means (46) is covered by a second cover (46), and preferably comprising a handle (50); and / or wherein the drive means (46) is an electric motor, and further comprising a battery and a display device (48) capable of displaying a state of charge of the battery.

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