WO2012095598A1

WO2012095598A1 - Device for automatically breaking the fall of someone working at a height

Info

Publication number: WO2012095598A1
Application number: PCT/FR2012/050054
Authority: WO
Inventors: Patrick Copin
Original assignee: Tractel Sas
Priority date: 2011-01-11
Filing date: 2012-01-09
Publication date: 2012-07-19
Also published as: ES2580960T3; FR2970183B1; EP2663369B1; EP2663369A1; FR2970183A1

Abstract

The invention relates to a device (1) for automatically breaking the fall of a worker connected by a tether with a connector to a fixing extension (9) of a control arm (5) of the device which is arranged on a vertical belay support (2), the device having a frame (3) and a stepped double jaw controlled by the control arm, the double jaw corresponding to a side of a deformable parallelogram with four sides formed by three rods articulated with each other or with the frame at the four corners (12, 13, 14, 15) of the parallelogram, with a vertical rod (4) and two other rods, called control rods (5, 6), curved internal extensions (7, 8) of the two control rods forming the double jaw, the vertical rod being articulated with the two control rods at the two outer corners (12, 13) and the two control rods (5, 6) being articulated with the frame at the two other, inner corners (14, 15), one of the control rods corresponding to the control arm (5), the belay support being able to be clamped between the frame and the inner extensions of the two control rods when these tilt. According to the invention, the fixing extension comprises a securing part (11), which is upwardly offset with respect to the axis of articulations (A1) of the control arm, the worker being connected to the control arm by securing the connector in the offset securing part (11).

Description

Automatic fall arrest device for workers at height

The present invention relates to an automatic fall arrest device for worker at height. It has applications in the field of personal safety.

The protection of workers at height is an obligation. Insulating devices for workers at height have therefore been proposed. Devices associated with a cable or equivalent, also called belaying support, which is vertical and on which the worker who is working at height is to be secured with a fall arrest device intended to arrest his eventual fall, are considered more particularly. To allow the worker to move up and down, the fall arrest device is in fact a device that can slide on a belay support and can therefore also be described as a slider. This type of device must meet certain standards in order to be used.

Among the fall arrest devices on belay cable, for example, those disclosed in the following documents are known: FR 1 519 616, FR 2 617 050, FR 2 751 233, FR 2 815 874 and FR 2 815 876. Also known are Fall arrest devices by US-5,855,251, US-4,034,828 and FR-2,548,913.

Although this type of device proved to be effective in most cases, it has occurred under certain conditions of fall of the worker, in particular towards the back or on the side, that the fall arrest device does not work. It was therefore decided to reinforce the standards with additional tests, taking into account previously unidentified risks.

The present invention provides an improved fall protection device that provides increased safety and that can meet the new requirements of the EN 353-1 standard, especially for falls back and / or side.

Thus, the invention relates to an automatic fall arrest device for worker at height, the worker being connected by a lanyard with a connector to a control arm of the device and the device being disposed on a vertical belay support, the device having a carcass traversed by the belay support and comprising a double stepped jaw controlled by the control arm, the double controlled staged jaw corresponding to a side of a parallelogram deformable parallelogram consisting of three rods articulated between them or to the carcass at the four corners of the parallelogram, with a vertical link parallel to the belay support on the opposite side to the double jaw and with the other two links, called control rods, parallel and opposite to each other, curved internal extensions of the two links of control forming the double jaw staggered, the vertical link being hinged the two control rods at the two outer corners of the parallelogram and the two control rods being hinged to the carcass at the two other internal corners of the parallelogram, one of the control rods corresponding to the control arm, the belay support being able to be clamped between the carcass and the curved internal extensions of the two control rods when they tilt, the worker being connected to an external extension, said attachment extension, the control arm which is opposite to its internal extension, the jaw being able to lock the belay support by tightening it during the fall of the worker causing a pulling down of the attachment extension of the control arm and can release the support of belaying during the worker's climb causing a traction upward of the attachment extension of the control arm.

According to the invention, the attachment extension comprises an attachment portion offset upwards with respect to the axis of articulation A1 of the control arm and its attachment extension, axis of joints passing through the two joints of said control arm, the worker being connected to the control arm by hooking the connector in the attachment portion shifted upwards relative to the axis of articulation A1 of the control arm and its attachment extension.

It may be noted that when the attachment extension of the control arm is pulled upwards, the device tends to release the belay support, the jaw not tightening the belay support, and makes free the device to slide along of the belay support by following the worker in his climb. The device can therefore also be called a slider. Due to the upward shift of the attachment portion of the control arm mounting extension, the tightening effect on the belay support of the same vertical force component applied to said attachment portion will be increased compared to the case where the attachment would be in the axis of the control arm joints. In the context of the invention, the terms connector and carabiner for the end of the lanyard intended to be hooked / fixed in the attachment portion of the attachment extension of the control arm, are considered equivalent.

In the following we use the terms "offset hooking part" to denominate the attachment portion which is shifted upwardly relative to the axis of joints A1 of the control arm and its attachment extension.

In various embodiments of the invention, the following means can be used alone or in any technically possible combination, are employed:

- the belay support is a cable,

the attachment part is shifted upwards with respect to the general axis A2 of the control arm and its fixing extension,

the device comprises a return spring-type biasing means bringing the control arm back to a position of at least beginning of tightening of the belay support in the absence of any external traction on said arm, the control arm corresponds to the lower control rod of the parallelogram in the operative position of the device,

the belay support is passed through a gutter made in the carcass,

the gutter corresponds to a rounded edge of the carcass,

the gutter is made by folding the carcass,

the belay support is clamped between the bottom of the gutter and the two curved internal extensions of the two control rods,

- The gutter is in two parts along its length, the gutter having laterally an alternating lateral opening between its two parts, said opening being a first side of the carcass in its first part and being on the other side of the carcass in its second part, the first and the second part of the gutter being separated by an opening of the bottom of the gutter to allow insertion by the edge of the belay support in the device,

- the opening of the bottom of the gutter is disposed substantially in the middle of the edge of the carcass,

the carcass is formed by the assembly of two half-shells partially enclosing the control rods of the deformable parallelogram and each comprising the bottom of its respective gutter portion,

at least one of the links of the deformable parallelogram results from the superposition of two flat elements fixed together,

the device is metallic,

- the carcass is metallic,

the links of the deformable parallelogram are metallic,

the control arm is metallic,

the worker is connected to the offset hooking part by means of a detachable connector or carabiner,

the offset hooking part comprises a passage hole of the connector or carabiner,

the device comprises means preventing the device from being removed from the belay support while the connector or carabiner is engaged in the passage hole of the connector,

the means preventing the device from being withdrawn from the belay support while the connector or carabiner is engaged in the passage hole of the connector or carabiner is a configuration of the device such that when the connector is placed in the passage hole, said connector forms an obstacle which limits the travel of the attachment extension by contact of the connector on the vertical link so that the release of the cable through the alternating lateral openings is impossible,

the means preventing the device from being removed from the belay support while the connector or carabiner is engaged in the passage hole of the connector or carabiner is an assembly of two hinged plates hinged together and at the control arm by a cam track system, in a locking configuration the plates limiting the possible deformation of the parallelogram and preventing the release of the belay support from the device,

the means preventing the device from being withdrawn from the belay support while the connector or carabiner is engaged in the passage hole of the connector or carabiner is such that, in a release configuration, the plates no longer limit the possible deformation of the parallelogram except if the connector or carabiner is engaged in the passage hole of the connector or carabiner,

the means preventing the device from being withdrawn from the belay support while the connector or carabiner is engaged in the passage hole of the connector or carabiner is double-triggered, the passage from one configuration to the other requiring two actions successively on the two plates,

the device comprises means preventing the disassembly of the connector or carabiner as long as the device is installed on the belay support,

a removable shutter under the effect of gravity closes the passage hole of the connector or carabiner when the device is in a non-functional vertical position, that is to say inverted with respect to the functional position, the control arm lying at the top instead of at the bottom,

the device comprises a keying system intended to ensure that it is installed on the belay support so that the control arm is down once installed,

- The keying system comprises an inclined rod disposed inside the device and fixed on one side of the carcass facing the opening of the bottom, said rod being inclined towards said opening, a substantially flat sealing washer sliding through its hole central on said inclined rod,

- The sealing washer is circular.

The present invention, without being limited thereby, will now be exemplified with the following description of embodiments and implementation in relation to:

Figure 1 which shows the device of the invention installed on a belay support and whose carcass is partly cut artificially (to allow visualization of the elements contained in the carcass) internal side, that is to say, side the gutter, the device,

2A and 2B which show the device of the invention respectively mounted upside down and in the right direction on the belay support to show the operation of the removable shutter in the passage hole of the connector,

Figures 3 and 3A and the corresponding cartridge which show the device respectively seen laterally and in section for visualization of the return spring clamping the jaws of the device, and 4A and 4B which show respectively the release configuration and the locking configuration of the two tilting plates of the means preventing the device from being withdrawn from the belay support while the connector or karabiner is engaged in the passage hole of the connector or carabiner .

The device is preferably configured so that at rest, that is to say in the absence of traction on the attachment portion of the control arm, the jaw is already applied against the belay support starting to tighten it, which corresponds to a pre-engagement of the device. Thus, the return spring and the structure of the device, in particular the relative positions of the points of articulation of the rods of the parallelogram on the one hand and the hooking part on the other hand are such that the pre-engagement allows both to maintain an ergonomic advantage when climbing. The rise, which causes traction to the top of the attachment part, is without a hitch or resistance. Similarly, during the descent, the descent is without a hitch. On the other hand, during a fall, there is an almost instantaneous blocking of the device on the belay support, which is for example a cable, even in the event of a rear or lateral fall. In other embodiments, the clamping takes place only if a component of vertical force downward is applied to the attachment extension and gripping portion of the control arm.

Thanks to the structure of the device, the locking (effective clamping of the jaw on the belay support to block a fall) on the belay support can be obtained at rest and / or upon detection of the least effort component to the bottom applied to the attachment portion of the attachment extension forming part of the control arm. It follows from the structure of the device that any rearward pull applied on the worker's connecting means to the connector / carabiner fixed in the attachment portion will create a force with a vertical force component on the control arm of the that the attachment portion is shifted upwards relative to the axis of joints A1 of the control arm passing through its two joints in the parallelogram. Thus, the proposed device responds more effectively than traditional devices in which the attachment portion is in the axis of the control arm or, worse, below. For the same pulling force towards the rear, the crushing force of the belay support is greater with the device of the invention. This effectively locks the device on the belay support, as the case may be, at rest or as soon as a minimum pull component combined with rear or side traction is exerted on the extension. fixing the control arm, in particular for a horizontal traction force, towards the rear or laterally, which is exerted on the connector.

In addition, the biasing means of the parallelogram, which is a return spring, has a stiffness such that the locking on the belay support is obtained as soon as the slightest rearward force is detected. Even preferably, the device is configured to apply a certain tightening of the belay support at rest, that is to say in the absence any traction or external force applied to the control arm. Thus, with the device of the present invention, it can be said that for the same rearward pulling force applied by the connector / carabiner to the device, the crushing force of the belay support is greater than that of a traditional device. Thus, the locking function in the event of a fall back is perfectly ensured:

In Figure 1, the vertical belay support 2 is in place in the device. To achieve this implementation, the belay support was passed through the opening of the bottom 17 of the gutter of the carcass 3 while the device was horizontal and the device was tilted to be positioned vertically so that the support of belay can be inserted into the gutter of the carcass which is in two parts along its length, the gutter having laterally a lateral opening 16 alternated between its two parts, said opening being a first side of the carcass in its first part and being on the other side of the carcass in its second part. It is understood that this implementation must be done so that once the belay support set up in the gutter, the control arm 5 is well below.

Preferably, a keying system preventing the installation of the device in the wrong direction along the belay support is implemented in the device. The keying system comprises a sealing washer which is placed in the opening 17 of the bottom and prevent and / or interfere with the insertion of the belay support in said bottom opening when the flat device is mis-oriented. To this end, an inclined rod disposed inside the device is fixed on one side of the carcass facing the opening of the bottom and is inclined towards this opening. The substantially flat circular washer is slid by its central hole on the inclined rod during manufacture of the device and can slide on this inclined rod. Due to the inclination of the rod, the sealing washer will more or less engage the opening 17 of the bottom according to its position along the rod. The shutter washer leaves free the opening 17 of the bottom when it is against the side of the carcass on which the inclined rod is fixed and it obstructs the opening of the bottom when it moves away from said side. Therefore, the inclined rod is placed on the side of the carcass, inside the device and facing the opening of the bottom so that by gravity, the device being flat, the washer comes to obstruct the opening 17 when the device is presented in the wrong way to take the belay support. In this way, the control arm 5 will always be down when the device has been installed on the belay support. The device is thus rendered irreversible in its mounting on a vertical belay support. The washer has a diameter such that it can not escape through the opening of the gutter bottom of the device. In a variant, the inclined rod is fixed and / or held at its other end on the other side of the carcass. In variants, the washer has a shape other than circular, including a square shape. Likewise, the rod and the hole of the washer can be circular or have a other shape, particularly complementary non-circular to prevent the rotation of the washer around the rod.

Two internal extensions 7, 8 of the control rods 5, 6 form the double stepped jaw which can clamp the belay support against the bottom of the trough of the carcass 3.

The deformable parallelogram corresponds to the articulated structure between the four corners 12, 13, 14, 15. The two outer corners 12 and 13 correspond to the two joints between the vertical link 4, external, and the two control rods 5 and 6. two other corners 14, 15, internal side of the parallelogram, correspond to the two joints of the control rods to the carcass. The internal extensions 7, 8 of the control rods 5, 6 are rounded so that when the control rods tilt around the internal corners / joints 14, 15, the belay support may be tight or loose at the bottom of the the gutter in the direction of tilting.

It follows from this parallelogram structure that the two inner corners / joints 14, 15 are fixed relative to the carcass and that the two outer corners / joints 12, 13 are movable relative to the carcass 3, the two control rods 5 , 6 remaining parallel during their tilts and the vertical link 4 coming closer to or away from the carcass and the belay support when tilting control rods. The tilting of the control rods 5, 6 results from the tractions performed on the offset hooking part 1 1 by the connector / karabiner passed through the through hole 10 of said hooking part. This offset hooking portion 1 1 is an upward extension of the attachment extension 9 of the control arm 5.

The attachment portion 1 1 and its through hole 10 of the connector / carabiner are offset upwards relative to the axis of joints A1 of the control arm passing through its two joints 13, 15. It is even noted that in the embodiment shown in FIG. 1, the attachment part 1 1 and its through-hole 10 of the connector / carabiner are also offset upwards with respect to the general axis A2 of the control arm and its extension of fixing 9.

In order to reinforce the security of the device, several complementary means are implemented in it. In particular, to prevent the worker from mounting upside down the device along the belay support and then make it non-functional, ie vertical device but with the control arm at the top instead of at the bottom as in normal use. To this end, in addition to the system described above, a removable shutter 18 for masking the passage hole of the connector / carabiner is placed on the attachment portion. When the device is mounted upside down (Fig.2A) on the belay support, the shutter closes by gravity / gravity effect on the hole and it is no longer possible for the worker to be able to introduce the connector . Thus, an anti-reversal function of the slider is available. This function makes it impossible to place the device on the belay support in the wrong direction (top and bottom inverted) by closing the hole for positioning the connector in the hooking part when it is placed in the upside down on the belay support. This function is achieved by gravity / gravity placement of a shutter in front of the hole where the connector / carabiner is to be placed. If the slider is placed on the belay support in the right direction, the shutter, which may be in the form of a tongue, does not close the passage hole of the connector in the fastening portion.

An exemplary shutter is shown in connection with Figures 2A and 2B. In Figure 2A, the device of the invention is mounted upside down on the belay support, control arm at the top, and the shutter obstructs the passage hole of the connector because it has tipped under the effect of gravity. The shutter therefore plays a key role as regards the direction of installation of the device on the belay support. In Figure 2B, the device is mounted in the right direction on the belay support and the shutter is retracted due to gravity, which releases the passage hole of the connector. The release movement that the shutter does is represented by a semi-circular arrow. In this Figure 2B, the attachment extension and the attachment part 1 1 offset from the control arm are partially shown cut to allow to see the shutter which is preferably in the thickness of the control arm, the arm of control resulting from the superposition of two plates. The shutter is a moving part, free or, preferably, articulated to the control arm.

Still in FIGS. 2A and 2B, it may be noted that the vertical link 4 comes into contact with the carcass 3 because no external force is applied to the passage hole of the offset hooking part 1 1 of the extension of 9 attachment of the control arm and that the device is not installed on the belay support. Under these conditions, the jaws of the device can come deep to the bottom of the gutter. Such a clamping configuration (virtual clamping in the absence of belay support) is obtained by the implementation of a return means, in this case spring type, which tends to tighten the jaws in the absence of opposite force applied to the control arm via a connector passed through the through hole 10 of the offset hooking part 1 1 of the attachment extension 9 of the lower control rod 5 forming the control arm .

This return spring 19 is presented in connection with Figures 3 and 3A. In Figure 3, an upwardly-acting force F is applied to the offset hooking portion 11 via a connector (not shown) passed through the through-hole 10, which is counter-productive. the action of said spring tending to tighten the jaws at the bottom of the gutter where normally the belay support. On the section AA shown in FIG. 3A and its enlargement cartridge, it is possible to see the return spring 19 placed between the two parts of the carcass 3, engaged on one of the parts and forcing the upper control rod and its internal extension 7. The spring is wound around the articulation 14 of the parallelogram. This articulation 14, like the other three 12, 13, 15, consists of a riveted system 20 allowing the movements of riveted elements, between them. It can be seen that the upper control rod with its internal extension 7 is formed of two superimposed plates, which explains the presence of fastening rivets 21 of the two plates. The control arm with its control rod 5, internal extension 8 and outer 9 and offset hooking part 1 1 is also formed of two superimposed plates riveted together.

A complementary means for enhancing the security of the device is also considered. It is intended to prevent the accidental dismantling of the belay device once the device is installed on the belay support and as long as the connector is engaged in the passage hole of the connector. For this purpose the geometry and the kinematics of the device are defined so that the connector placed in the through hole acts as an obstacle which limits the travel of the attachment extension 9 by contact of the connector on the vertical link 4, (FIG. 3) . As a result, the cable can not be released from the alternating lateral openings since it is not possible to raise the fixing extension 9 sufficiently upwards (Figure 3). On the other hand, in the absence of the connector, the extension of fixation 9 and its attachment portion 1 1 may, when they rise upwards (with reference to the assembly of FIG. 3), engage behind the vertical link 4, which makes it possible to sufficiently disengage the internal extensions 7, 8, adapted shapes, control rods 5, 6 and release the alternate side openings through which the cable can then pass. Indeed, to release the alternating side openings, it is necessary to apply to the attachment extension 9 and its attachment portion 1 1 a sufficient movement, contrary to that required to lock the device on the belay support.

It can be noted with this system that it is impossible for the worker to install the device on the support belay if he first hooked the connector to the device before installing it on the belay support. As a result, the inverted mounting of the device on the belay support is impossible because of the presence of the shutter 18 whose operation has been explained above.

The following complementary means for enhancing the security of the device is also considered. It is intended to prevent the accidental removal of the connector / carabiner from the attachment portion once the device is installed on the belay support and the connector / carabiner is attached to the attachment portion. For example, this means can be a lug of the connector / carabiner forcing the worker to install the connector / karabiner in an orientation and / or path that can not reproduce inverted naturally (without human operation). Alternatively, this means can be a housing around the region of the shackle portion of the control arm, housing that is manually removable to allow the installation of the connector / carabiner.

By way of another example of means intended to reinforce the safety of the device, FIGS. 4A and 4B are shown, the one preventing the device from being removed from the belay support as long as the connector or carabiner is engaged in the passage hole of the connector or carabiner. Two tilting plates 22, 23 hinged together and on the control arm by a cam track system, can take two configurations together: a release configuration and a locking configuration. The user must act on these plates to pass blocking or release configurations and vice versa.

In FIG. 4A, the two plates 22, 23 are in the release configuration and the parallelogram is free to deform except that as long as the connector or carabiner is in its hole, the possible deformation is limited and does not allow the release of the support. belay device because one of the plates will abut against the connector or carabiner. On the other hand, when there is no connector or carabiner, the parallelogram can be completely deformed until it releases the belay support or the access of the belay support to the device. It is therefore necessary that the connector or karabiner is not mounted in its hole in order to install or uninstall the device on the belay support.

In Figure 4B the two plates 22, 23 are in the locking configuration and the parallelogram can not be deformed to release the belay support because one of the plates abuts against the vertical link.

The movements of the two plates between them depend on the shape of the cam paths connecting them and a double-expansion system is implemented: we must successively operate the two plates to move from one configuration to another.

Naturally, the present invention is not limited to the particular embodiments which have just been described, but extends to all variants and equivalents in accordance with its spirit. Thus, it is clear that the invention can be declined according to many other possibilities without departing from the scope defined by the description and the claims.

Claims

1. Device (1) for automatic fall arrest for worker at height, the worker being connected to a control arm (5) of the device and the device being intended to be installed on a vertical belay support (2), the device having a carcass (3) traversed by the belay support and comprising a double stepped jaw controlled by the control arm, the double controlled step jaw being arranged on one side of a parallelogram deformable parallelogram consisting of three articulated rods between them and / or the carcass at the four corners (12, 13, 14, 15) of the parallelogram, with a vertical link (4) parallel to the belay support on the opposite side to the double jaw and with the other two rods, said control rods (5, 6), parallel and opposite each other, curved internal extensions (7, 8) of the two control rods forming the double stepped jaw, the vertical link being articulated to the two control rods at the two outer corners (12, 13) of the parallelogram and the two control rods (5, 6) being articulated to the carcass at the two other internal corners (14, 15) of the parallelogram, the support belay device that can be clamped between the carcass and the curved internal extensions of the two control rods when they tilt, characterized in that one of the control rods corresponds to the control arm (5), the worker being connected to an extension external, said attachment extension (9), the control arm which is opposite its internal extension, the double jaw can block the belay support by tightening it during the fall of the worker causing a pull down the extension of fixing the control arm and can release the belay support during the climb of the worker causing an upward traction of the attachment extension of the control arm and in that that the attachment extension comprises a hooking portion (1 1) offset upwards with respect to the axis of joints (A1) of the control arm and its attachment extension, axis of joints passing through the two joints of said control arm, the worker being connected to the control arm by hooking a connector in the hooking part (1 1) offset upwards relative to the axis of joints (A1) of the control arm and its attachment extension.

2. Device according to claim 1, characterized in that it comprises a return spring type biasing means bringing the control arm into a position of at least beginning of tightening of the belay support in the absence of any external traction on said arm.

3. Device according to claim 1 or 2, characterized in that the control arm (5) corresponds to the lower control rod of the parallelogram in operative position of the device.

4. Device according to claim 1, 2 or 3, characterized in that the belay support is passed through a gutter made in the carcass and said support belay is clamped between the bottom of the gutter and the two internal extensions (7, 8) curves of the two control rods.

5. Device according to claim 4, characterized in that the gutter is in two parts along its length, the gutter laterally having a lateral opening (16) alternating between its two parts, said opening being a first side of the carcass in its first part and being on the other side of the carcass in its second part, the first and the second part of the gutter being separated by an opening of the bottom (17) of the gutter to allow insertion by the slice belay support in the device.

6. Device according to any one of claims 4 or 5, characterized in that the carcass (3) is formed of the assembly of two half-shells partially enclosing the control rods deformable parallelogram and each having the bottom of its respective gutter part.

7. Device according to any one of the preceding claims, characterized in that at least one of the links of the deformable parallelogram results from the superposition of two flat elements fixed together.

8. Device according to any one of the preceding claims, characterized in that the worker is connected to the hooking part (1 1) offset by means of a removable connector or carabiner and in that the part of staggered hooking comprises a connector passage hole and the device comprises means preventing the device from being withdrawn from the belay support while the connector or carabiner is engaged in the passage hole of the connector.

9. Device according to claim 8, characterized in that the means preventing the device from withdrawing from the belay support as the connector or carabiner is engaged in the passage hole of the connector or carabiner is a configuration of the device such as when the connector or carabiner is placed in the through hole, said connector forms an obstacle which limits the stroke of the attachment extension (9) by contact of the connector on the vertical link (4) so that the release of the cable through the side openings alternate is impossible.

10. Device according to claim 8, characterized in that the means preventing the device from withdrawing the belay support as the connector or carabiner is engaged in the passage hole of the connector or carabiner is an assembly of two tilting plates (22). , 23) articulated to each other and to the control arm by a cam track system, in a locking configuration the plates limiting the possible deformation of the parallelogram and preventing the release of the belay support of the device.

1 1. Device according to Claim 10, characterized in that the means preventing the device from being withdrawn from the belay support while the connector or carabiner is engaged in the passage hole of the connector or carabiner is such that, in a release configuration, the plates no longer limit deformation possible parallelogram unless the connector or carabiner is engaged in the passage hole of the connector or carabiner.

12. Device according to claim 1 1, characterized in that the means preventing the device from withdrawing the belay support as the connector or karabiner is engaged in the passage hole of the connector or carabiner is double trigger, the passage of one configuration to another requiring two actions successively on the two plates.

13. Device according to any one of the preceding claims, characterized in that the hooking part (1 1) offset has a hole (10) for the connector or karabiner and in that a removable shutter under the effect gravity closes said passage hole (10) when the device is in a non-functional vertical position.

14. Device according to any one of the preceding claims, characterized in that it comprises a polarizing system to ensure that it is installed on the belay support so that the control arm (5) either at the bottom once installed, the polarizing system comprising an inclined rod disposed inside the device and fixed on one side of the carcass opposite the opening (17) of the bottom, said rod being inclined towards said opening, a substantially flat shutter washer sliding through its central hole on said inclined rod.