EP3713868B1 - Portable hoisting device - Google Patents

Description

TECHNICAL AREA

The present invention relates to a portable lifting device for a ladder, in particular a portable hoisting device for a fixed ladder, in particular for a cage ladder.

STATE OF THE ART

Many buildings and industrial installations, in particular installations for the production of electricity from fuel, have ladders fixed ("permanently") to walls and allowing operators to move around the installation or building, for example to carry out maintenance or control operations.

When these operations require the use of an object, for example a tool or a measuring device, and no fixed hoisting means are provided near a ladder, it may be necessary to an operator having climbed the ladder, to hoist the object suspended from a deformable link such as a rope, along the ladder, or conversely to lower the object suspended from a deformable link, also along the 'ladder.

The hoisting and lowering of the object are all the more difficult as the object is bulky, heavy, and / or fragile, and it is frequent that no lifting device capable of facilitating these actions is integrated into the 'installation.

There is therefore a need for a hoisting device which can be easily transported and set up by an operator climbing a ladder.

Patent JPH11159270 describes a spacer device for a mobile ladder which can be secured to two adjacent rungs of the ladder by fixed hooks and by sliding hooks on which springs are supported.

The body of the spreader device comprises a main portion comprising an assembly of tubes forming an "H" and arranged to extend along the ladder, "under" the ladder ie. between the ladder and the wall of a building against which the ladder is supported by means of the spacer device.

The body of the device further comprises a bearing portion on the building wall, which forms an angle with the longitudinal axis of the ladder and which comprises several bars.

This device is used with a hoist attached to one of the bars and allowing a ground operator to hoist an air conditioning unit "under" the ladder, from the ground on which the ladder rests to a height. support previously fixed to the wall against which the ladder rests.

This device, which extends between the ladder and the wall against which the ladder rests, is not suitable for hoisting a load along a ladder rigidly fixed to a wall.

This device is bulky, in particular because of the rigid connection between the main "H" shaped portion and the bearing portion; therefore, it is not suitable for hoisting a load up a ladder equipped with a crinoline, inside the crinoline, nor is it suitable for being carried by an operator climbing a ladder. ladder, in particular a crinoline ladder.

This bulky device is also unsuitable for being secured to a ladder, then detached from the ladder, by an operator located on the ladder.

This device does not allow an operator to respect the elementary safety rules which must be applied to climb a ladder and perform work at height, in particular the rule requiring the operator to have three points of support on the ladder at all times. .

The patent application US 2016/245019 A1 discloses a hoisting device comprising the following characteristics: a gallows comprising a mast and a load arm - or jib; means for reversible engagement of the mast with two rungs of a ladder; and a cross member for support on one of the bars and in that the cross member is integral with the mast.

DISCLOSURE OF THE INVENTION

An object of the invention is to provide a portable hoisting device for a fixed ladder, which overcomes, in part at least, the shortcomings or drawbacks of known devices.

A portable device for hoisting a load along a fixed ladder, which is light, compact, safe to use, adaptable to different types of ladders in diameter and spacing of the rungs, portable other than by hand, which can be fastened to the ladder quickly and with one hand, so as to allow an operator carrying the device to climb the ladder, to fasten the device to the ladder, and to continue his progression on the ladder, safely.

According to the invention, there is proposed a hoisting device which comprises a bracket comprising a mast and a load arm retractable along the mast, means for reversible engagement (hooking) of the mast with two rungs of a ladder , a carrying member of the device, and a cross member for bearing on one of the bars, the carrying member and the cross member being integral with the mast.

The means for reversible engagement of the mast with two rungs of a ladder preferably comprise a first member for fastening to a first ladder rung (which is hereinafter referred to as "upper rung"), which is fixed to the mast. preferably rigidly, and a second member for fastening to a second ladder rung (which is hereinafter referred to as "lower rung" and is substantially parallel to the first ladder rung), which is mounted to move relative to the mast, of so that the reversible engagement means are adjustable (deformable), and the reversible engagement means include means for returning the hooking members to one another.

• un mât présentant un axe longitudinal ;
• une flèche - ou bras de charge - solidaire du mât au voisinage d'une première extrémité longitudinale (ou sommet) du mât ;
• un organe de port du dispositif qui est solidaire du mât ;
• une pièce d'appui (sur un barreau supérieur) solidaire du mât, qui s'étend transversalement (par rapport à l'axe longitudinal), et qui porte (ou comporte) un premier organe d'accrochage (au barreau supérieur) s'étendant de part et d'autre du mât, de préférence sensiblement symétriquement par rapport à l'axe longitudinal ;
• un second organe d'accrochage (au barreau inférieur) monté coulissant par rapport au mât, au voisinage d'une seconde extrémité longitudinale (ou base) du mât ;
• un organe de rappel du second organe d'accrochage vers le premier organe d'accrochage;

et dans lequel la flèche est escamotable le long du mât, pouvant passer d'une configuration déployée dans laquelle l'extrémité libre de la flèche s'étend à une première distance de l'axe longitudinal, à une configuration escamotée dans laquelle l'extrémité libre de la flèche s'étend à une seconde distance de l'axe longitudinal qui est inférieure à la première distance.In other words and according to another aspect of the invention, there is proposed a hoisting device which comprises:

• a mast having a longitudinal axis;
• a boom - or load arm - integral with the mast in the vicinity of a first longitudinal end (or top) of the mast;
• a device carrying member which is integral with the mast;
• a support piece (on an upper bar) integral with the mast, which extends transversely (with respect to the longitudinal axis), and which carries (or comprises) a first attachment member (to the upper bar) extending on either side of the mast, preferably substantially symmetrically with respect to the longitudinal axis;
• a second attachment member (to the lower bar) slidably mounted with respect to the mast, in the vicinity of a second longitudinal end (or base) of the mast;
• a return member from the second hooking member to the first hooking member;

and in which the boom is retractable along the mast, being able to pass from a deployed configuration in which the free end of the boom extends a first distance from the longitudinal axis, to a retracted configuration in which the end free of the boom extends a second distance from the longitudinal axis which is less than the first distance.

Each of the fastening members can have the shape of a bent tongue, hook, or rider, the shape and dimensions of each fastening member being adapted / chosen so that the member can overlap (or partially surround) a portion length of a ladder rung, so as to retain the device in contact with the ladder rung.

The invention provides, when the boom is retracted, a compact device, slender and balanced, which can easily be grasped and manipulated with one hand by an operator standing on the ladder and grasping the device by the mast, both to engage it on its shoulder and to release it from its shoulder, to secure it to two parallel bars by deformation (extension) of the reversible engagement means, and to separate it from the bars by manipulation reverse.

The carrying member of the device may comprise or be essentially constituted by a first deformable link, of elongated shape, for example a strap or strip of textile material, of which the two ends are secured to the mast, preferably respectively in the vicinity of the two ends of the mast.

The first deformable link can be elastic; alternatively, the length of the link may be greater than the distance separating the two points of attachment of the link to the mast, so that an operator can engage his arm between the mast and the link until the device is suspended from his shoulder, the link then forming a strap.

According to one embodiment, the extension of the reversible engagement means is accompanied by an elongation of a return member (such as a spring) of the return means. Alternatively, this extension is accompanied by a compression of this return member.

The extension of the reversible engagement means can be obtained, after the second attachment member has been engaged with the lower bar, by traction exerted by the operator on the mast, substantially along the longitudinal axis of the mast and in the direction of the upper bar, with a tensile force sufficient to overcome the return forces exerted by the return means as well as the friction forces during the sliding of the second hooking member along the mast.

The intensity of this tensile force can be situated in a range going from approximately one Newton (1N) up to approximately ten Newton (10N).

The device comprises a member or device for locking the reversible engagement means, in particular a locking member preventing the sliding of the second hooking member along the mast, such as a cam clamping lever.

The retractable and deployable jib may include one or two articulated arm (s) on the mast, in particular one or two pivoting arms along one or two pivot axes which is (are) substantially perpendicular (s) to the longitudinal axis of the mast , in particular parallel (s) to the longitudinal axis of the support part.

According to one embodiment, the boom comprises a pulling arm and a load arm. Alternatively, the boom may have an arm of load and a deformable tie rod, such as a cable, which connects the load arm to the mast.

This allows the jib to be retracted by pivoting the arm (s) relative to the mast.

For this purpose in particular, at least part of the mast may have, in cross section, a concavity oriented towards the arm (s) of the jib. This concave part can thus receive a part of the arm, in the boom retracted position, while ensuring the rigidity of the mast.

The device may include a member for mutually reversible fixing of the two arms of the boom, such as a pin, this fixing member being kept integral with the device, in particular integral with the load arm, by a second deformable link such as a cable.

The device may comprise a member for locking the member for mutual reversible fixing of the two arms, which may be integral with - in particular integrated into - the member for mutual fixing of the arms, this locking member for example being constituted by a ball of a safety ball pin.

The device may further include a shackle fixed in the vicinity of the free end of the jib, and / or a carabiner serving to suspend a lifting pulley from the shackle and / or the jib, the pulley possibly comprising a brake for a rope or hoisting rope engaged in the pulley.

The invention provides a compact, lightweight hoisting device that is easy to carry on the shoulder. In particular, the dimensions of the parts of the hoisting device and the materials chosen to produce them can make it possible to obtain a device whose mass is less than 5 or 10 kilograms, the device making it possible to hoist a load of several tens of kilograms.

• porter le dispositif à l'épaule, sur le devant du corps ;
• gravir une échelle jusqu'au voisinage d'une plateforme qui peut être prévue au voisinage du sommet de l'échelle ;
• engager l'organe d'accrochage mobile sous un barreau « inférieur » de l'échelle s'étendant sensiblement au niveau de la taille de l'opérateur ;
• en tenant le dispositif d'une main par le mât, provoquer l'extension des moyens d'engagement réversible puis engager l'organe d'accrochage fixe sur un barreau « supérieur » de l'échelle, en rabattant le mât contre ce barreau ;
• verrouiller les moyens d'engagement réversible ; puis, l'opérateur se tenant sur la plateforme :
• déployer la potence ;
• accoupler le bras de charge au tirant par la goupille à bille ; et
• suspendre une poulie de levage au bras de charge.

A method of installing the device on a ladder may include the following operations:

• wear the device on the shoulder, on the front of the body;
• climb a ladder to the vicinity of a platform which may be provided in the vicinity of the top of the ladder;
• engage the movable attachment member under a "lower" rung of the ladder extending substantially at the level of the waist of the operator;
• by holding the device with one hand by the mast, cause the reversible engagement means to extend and then engage the fixed hooking member on an “upper” rung of the ladder, by folding the mast against this rung;
• lock the reversible engagement means; then, the operator standing on the platform:
• deploy the gallows;
• couple the load arm to the tie rod by the ball pin; and
• suspend a lifting pulley from the load arm.

• séparer la poulie de levage du bras de charge ;
• désaccoupler le bras de charge du tirant par extraction de la goupille à bille, de sorte que le bras de charge et le tirant pivotent et s'escamotent le long du mât ; puis, l'opérateur se positionnant sur l'échelle devant le dispositif :
• mettre l'organe de port à l'épaule ;
• déverrouiller les moyens d'engagement réversible ;
• en tenant le dispositif d'une main par le mât, provoquer l'extension des moyens d'engagement réversible puis dégager l'organe d'accrochage fixe du barreau « supérieur » de l'échelle, en écartant la partie supérieure du mât de ce barreau ; puis
• dégager l'organe d'accrochage mobile de sous le barreau « inférieur » de l'échelle.

Conversely, a method of removing the device may include the following operations:

• separate the lifting pulley from the load arm;
• disconnect the load arm from the tie rod by extracting the ball pin, so that the load arm and the tie rod pivot and retract along the mast; then, the operator positioning himself on the ladder in front of the device:
• put the carrying organ on the shoulder;
• unlock the reversible engagement means;
• by holding the device with one hand by the mast, cause the reversible engagement means to extend, then release the fixed hooking member from the "upper" rung of the ladder, by moving the upper part of the mast away from this bar; then
• release the movable hooking member from under the "lower" rung of the ladder.

Other aspects, characteristics, and advantages of the invention appear in the following description which refers to the figures. appended and illustrates, without any limiting nature, embodiments of the invention.

BRIEF DESCRIPTION OF THE FIGURES

• The figure 1 illustrates, in perspective view, a hoisting device whose boom is deployed. The figure 2 is a perspective view from another angle of the illustrated device figure 1 .
• The figure 3 illustrates, in side view, the illustrated hoisting device figures 1 and 2 .
  Each of the figures 1 to 3 furthermore comprises, in the lower part of the figure, a cutout illustrating an extreme position of the movable lower member for fastening the device to a ladder rung.
• The figure 4 illustrates, in side view, the illustrated device figure 3 in a jib retraction configuration obtained by tilting the arms of the jib along the mast of the device.
• The figure 5 illustrates, in top view, the illustrated device figure 3 and is a view along V of the figure 3 .
• The figure 6 schematically illustrates an operation for engaging a lower hooking member of the hoisting device with a lower ladder rung, and the figure 7 schematically illustrates a subsequent operation of engagement of an upper hooking and support member of the hoisting device with another bar extending above the lower bar.
• The figure 8 schematically illustrates an operation of hoisting an object using a hoisting device secured to the two upper rungs of a "non-emerging" ladder, ie. the top of which extends to the level of a platform on which an operator can stand, and the figure 9 schematically illustrates an operation of hoisting an object using a hoisting device secured to two successive rungs of a "emerging" ladder, ie. the top of which extends above a platform on which an operator can stand.

DETAILED DESCRIPTION OF THE INVENTION

Unless expressly or implied otherwise, elements or bodies - structurally or functionally - identical or similar, are designated by identical references in the various figures.

By reference to figures 1 to 9 , the device 10 is used to hoist a load marked 104 figures 8 and 9 , which is suspended from a deformable link such as a rope, along a fixed ladder 102 comprising at least two bars 100, 101 superimposed on which the device 10 is temporarily secured for this purpose.

The device 10 comprises a bracket 20 comprising a mast 21 extending along a longitudinal axis 70, and two arms 22, 23 articulated with respect to the mast and forming a retractable jib along the mast.

For hoisting a load, traction is performed by an operator on a rope (not shown) engaged in a pulley (not shown) suspended from the boom 22, 23.

For this purpose, the device may include, as illustrated figures 1 to 3 , a shackle 90 fixed in the vicinity of the free end of the boom, and a carabiner suspended from the shackle and supporting the lifting pulley.

The pulley may include a brake for the hoisting rope engaged in the pulley.

In the illustrated embodiments figures 1 to 5 , the mast 21 consists of a bar whose cross section has a "U" shape.

The upper arm 23, serving as a tie rod, is fixed to the upper end 74 of the mast 21, between the wings of the U-shaped profile 21, by a pivot with an axis 72 perpendicular to the axis 70.

The lower arm 22, serving as a load arm and to the free end of which the shackle 90 is fixed, is fixed at a distance from the upper end 74 of the mast 21, between the wings of the U-shaped profile 21, by a pivot d 'axis 71 parallel to axis 72.

The arms 22, 23 can thus extend partly between the wings of the U-shaped profile 21, along this profile, when their free ends respective ones have been mutually dissociated, as illustrated figures 4 , 6, and 7 .

Each arm 22, 23 respectively comprises a yoke 26, 27 (cf. figure 4 ) pierced with an orifice for passage of a ball pin 80 (cf. figure 3 in particular) serving as a reversible mutual fixing member of the arms 22, 23.

To deploy the boom, the operator rotates the arms 22, 23, from their retracted position along the mast to a deployed position illustrated figure 1 to 3 and 5 , position in which the holes of the yokes 26, 27 are aligned so that the operator can engage the pin 80 in these holes.

To avoid the fall or loss of the pin when the latter is not engaged in the orifices of the yokes, the pin is connected to one of the parts of the device by a deformable link 81 (cf. figure 3 ); the pin is for example connected, by the link 81, to another yoke 28 provided on the arm 22.

To prevent the untimely exit of the pin 80 from the yokes, the pin comprises a locking member formed by a ball.

The device 10 comprises a cross member 50 (cf. Figure 2 in particular) support and hooking on a ladder rung, which is rigidly fixed to the arm 21, in a substantially “central” portion of the mast, ie. in an intermediate portion between the upper 74 and lower 75 ends of the mast.

The cross member 50 extends along a transverse axis 73 (with reference to the axis 70) which is parallel to the axes 71, 72 of pivoting of the arms.

The arms 22, 23 extend from a first side of the mast 21, while the cross member 50 extends from a second side of the mast opposite to the first side.

• une première aile 34 sert à fixer (rigidement) la traverse 50 au mât 21 ;
• une aile « centrale » 31, qui forme un angle droit avec l'aile 34 de façon à s'étendre dans un plan perpendiculaire à l'axe 70 du mât ; et
• une troisième aile 32, qui forme un angle obtus avec l'aile 34, sert à retenir la traverse 50 (et le dispositif 10) engagée avec le barreau 100 tant que la traverse repose sur ce barreau.

The cross member 50 comprises - and is essentially constituted by - three flat wings (cf. figure 4 in particular) elongated along the axis 73:

• a first wing 34 serves to (rigidly) fix the cross member 50 to the mast 21;
• a "central" wing 31, which forms a right angle with the wing 34 so as to extend in a plane perpendicular to the axis 70 of the mast; and
• a third wing 32, which forms an obtuse angle with the wing 34, serves to retain the cross member 50 (and the device 10) engaged with the bar 100 as long as the cross member rests on this bar.

The central wing 31 can serve as a bearing surface on an upper ladder bar 100, when the diameter of this bar is less than or equal to the width of the wing 31. Otherwise, the cross member 50 d ' support and hooking rests on the bar 100 by its two lateral wings 32 and 34.

The length of the cross member 50 is greater than the width of the mast to ensure stable support and hooking of the device on the bar 100.

As shown figure 2 , the central part of the hooking wing 32 is provided with a cutout 32a serving to reduce the mass of the cross member. Consequently, the hooking wing 32 comprises two projecting tongues extending respectively at the two longitudinal ends of the cross member 50, so that these hooking tongues extend on either side of the mast.

As shown figures 2 and 3 in particular, the cross member 50 has the shape of a rider, the concavity of which is directed towards the lower end 75 of the mast.

The device 10 comprises a second hooking member 33 with a second ladder bar 101 parallel to the first ladder bar 100, which is rigidly fixed to a blade 29 slidably mounted relative to the mast, between the wings of the mast and against the core of the mast, along the longitudinal axis 70 of the mast, in the vicinity of the lower end 75 of the mast, so that the attachment member 33 is movable (sliding) relative to the mast 21.

The mobile hooking member 33 extends opposite the cross member 50 and has the shape of a jumper flared upwards, the concavity of which is directed towards the upper end 74 of the mast and towards the cross member 50.

As shown figures 2 to 4 , the movable hooking member 33 is formed of three plane wings parallel to the axis 73, and has a cross section identical to that of the cross member 50.

The shape and dimensions of the cross member 50 and of the movable attachment member 33 are adapted so that each of these parts 33, 50 can partially surround a longitudinal portion of a ladder rung: the cross member 50 overlaps the part. upper part of a longitudinal portion of the upper bar 100, and the mobile hooking member 33 surrounds the lower part of a longitudinal portion of the lower bar 101 (cf. figures 3 and 7 to 9 ).

The flared shape of the cross member 50 and of the movable hooking member 33 allows them to adapt to bars of different diameters by self-centering.

The device 10 also comprises a return member constituted by a spring 35 (cf. figures 6 and 7 ) a first end of which is fixed to the blade 29 and a second end of which is fixed to the mast, so that this spring is biased in traction when the movable hooking member 33 is moved away from the lower end 75 of the mast, as shown schematically on the figures 1 to 3 and 6 .

The spring 35 serves to return the blade 29 and the member 33 towards the upper end of the mast, ie. towards the traverse 50.

The spring 35 allows the device to be self-held on the scale when it is not locked.

In addition, the spring 35 also serves to self-adapt the support and hooking members (31 to 34) according to the center distance of the ladder rungs.

The blade 29 is pierced with a longitudinal opening through which extends a rod fixed to the core of the mast and which is integral with a lever 24 with pivoting cam 36 able to press on the blade 29.

The cam lever 24 serves to prevent, in a first configuration (orientation) of the lever, and conversely to allow in a second configuration (orientation) of the lever, the sliding of the blade 29 and of the second hooking member 33 relative to the mast.

The cross member 50 and its support and hooking members 31, 32, 34 can be positioned eccentrically on the mast, ie. closer to the lower end 75 of the mast than to the upper end 74, so that the boom of the device extends above the bearing 103 (or platform shown figures 8 and 9 ), especially when the ladder stops at the landing as illustrated figure 8 , thus allowing the operator in charge of recovering the object 104 and located on the landing, to grasp the object more easily.

The device 10 further comprises a strap 40 for transporting the device (cf. figure 7 ), the two ends 41, 42 of which are secured to the mast, respectively in the vicinity of the two ends 74, 75du mast.

Unless the strap 40 is elastic, its length is greater than the distance between its two points 41, 42 for attachment to the mast.

• un opérateur portant le dispositif 10 (dont la flèche est escamotée) à l'épaule (par exemple l'épaule gauche) par la sangle 40 gravit une échelle jusqu'à une hauteur déterminée, le dispositif étant soutenu à l'épaule, entre l'opérateur et l'échelle ;
• l'opérateur se tenant avec sa main ne correspondant pas à l'épaule portant le dispositif (par exemple sa main droite) serrée/accrochée à un barreau de l'échelle, sépare sa main opposée (sa main gauche) de l'échelle, saisit le dispositif par son mât, d'une main (de sa main gauche), en conservant la sangle à l'épaule afin d'éviter une chute accidentelle du dispositif ;
• l'opérateur engage l'organe 33 inférieur mobile d'accrochage du dispositif sous un barreau 101 d'échelle s'étendant par exemple légèrement au dessus de sa ceinture, en maintenant (par sa main gauche) le mât incliné comme illustré figure 6, c.à.d. dont l'extrémité supérieure 74 s'étend à distance des barreaux de l'échelle, entre l'échelle et le torse de l'opérateur ;

• l'opérateur exerce alors (par sa main gauche) une traction verticale ascendante sur le mât illustrée figure 6 par la flèche 95, qui est suffisante pour provoquer l'extension du ressort 35 et le coulissement de la lame 29 et de l'organe 33 inférieur d'accrochage, par rapport au mât, jusqu'à la configuration illustrée figure 6 dans laquelle les organes 31, 32 supérieurs d'engagement s'étendent au-dessus du barreau 100 surplombant le barreau 101 avec lequel est engagé l'organe 33 ;
• dans cette configuration, l'opérateur plaque (par sa main gauche), par un mouvement de pivotement illustrée figure 6 par la flèche 96, le mât contre les barreaux d'échelle, puis relâche son effort de traction (95) de sorte que les organes 31, 32, 34 d'engagement s'engagent avec le barreau 100 et que la traverse 50 vienne en appui sur ce barreau ;
• l'opérateur peut alors lâcher le mât du dispositif, faire coulisser la sangle le long de son bras (gauche), et verrouiller (par sa main gauche) le coulissement de la lame 29 en agissant sur le levier 24 à came 36 ;
• l'opérateur peut ensuite continuer sa progression sur l'échelle jusqu'à une plateforme proche du sommet du mât (et de l'échelle), déployer ensuite la flèche de la potence, verrouiller l'assemblage mutuel des bras 22, 23 par la goupille à bille, engager un mousqueton portant une poulie dans la manille suspendue à la flèche, et engager une corde de levage dans la poulie.

The device can be used as follows:

• an operator carrying the device 10 (the arrow of which is retracted) on the shoulder (for example the left shoulder) by the strap 40 climbs a ladder to a determined height, the device being supported on the shoulder, between the 'operator and scale;
• the operator standing with his hand that does not correspond to the shoulder carrying the device (for example his right hand) clamped / hung on a rung of the ladder, separates his opposite hand (his left hand) from the ladder, grasps the device by its mast, with one hand (with his left hand), keeping the strap on the shoulder in order to prevent an accidental fall of the device;
• the operator engages the lower movable hooking member 33 of the device under a ladder bar 101 extending for example slightly above his belt, while maintaining (by his left hand) the mast inclined as illustrated figure 6 , i.e. whose end upper 74 extends away from the rungs of the ladder, between the ladder and the operator's torso;

• the operator then exerts (by his left hand) an upward vertical traction on the illustrated mast figure 6 by the arrow 95, which is sufficient to cause the extension of the spring 35 and the sliding of the blade 29 and of the lower hooking member 33, relative to the mast, to the illustrated configuration figure 6 wherein the upper engagement members 31, 32 extend above the bar 100 overhanging the bar 101 with which the member 33 is engaged;
• in this configuration, the operator plate (by his left hand), by a pivoting movement illustrated figure 6 by the arrow 96, the mast against the ladder rungs, then releases its tensile force (95) so that the engagement members 31, 32, 34 engage with the bar 100 and that the cross member 50 comes in support on this bar;
• the operator can then let go of the mast of the device, slide the strap along his arm (left), and lock (by his left hand) the sliding of the blade 29 by acting on the lever 24 with cam 36;
• the operator can then continue his progression on the ladder to a platform close to the top of the mast (and the ladder), then deploy the jib of the jib crane, lock the mutual assembly of the arms 22, 23 by the ball pin, engage a carabiner with a pulley in the shackle suspended from the boom, and engage a lifting rope in the pulley.

A second operator located at a lower level, at the bottom of the ladder, can then lift a load suspended from the lifting rope.

Once the load has been placed on the platform, the operator can proceed, in reverse order to the previous one, with the reverse operations to retract the boom, put the device strap back on the shoulder, then detach the device from the ladder.

Claims (9)

1. A hoisting device (10) including:

   - a bracket (20) including a mast (21) and a load arm (22, 23) - or boom - retractable along the mast;

   - means (30) for reversibly engaging the mast with two rungs (100, 101) of a ladder;

   - a member (24) for latching the reversible engagement means;

   - a member (40) for wearing the device on a shoulder; and

   - a cross member (50) for pressing on one of the rungs,

   and in that the wearing member and the cross member are integral with the mast.
2. The device according to claim 1, wherein the means (30) for reversibly engaging the mast with two rungs of a ladder include a first member (31, 32, 34) for hanging to a first ladder rung (100), which is attached to the mast, a second member (33) for hanging to a second ladder rung (101) which is movably mounted relative to the mast, and means (35) for returning the hanging members (31 to 34) to each other.
3. The device according to claim 1 or 2, wherein:

   - the mast has a longitudinal axis (70);

   - the load arm - or boom - is integral with the mast in the vicinity of a first longitudinal end (74) of the mast;

   - the pressing cross member (50) extends transversally (73) relative to the longitudinal axis (70), and carries (or includes) a first member (31, 32, 34) for hanging to a first ladder rung (100) which extends on either side of the mast, preferably substantially symmetrically relative to the longitudinal axis (70);

   - the device includes a second member (33) for hanging to a second ladder rung (101) parallel to the first ladder rung, said second hanging member (33) being slidably mounted relative to the mast, in the vicinity of a second longitudinal end (75) of the mast;

   - the device includes a member(35) for returning the second hanging member (33) to the first hanging member (31, 32, 34);

   - the retractable boom can switch from an extended configuration in which the free end of the boom extends at a first distance from the longitudinal axis (70), to a retracted configuration in which the free end of the boom extends at a second distance from the longitudinal axis (70) which is lower than the first distance;

   the shape and dimensions of each hanging member (31 to 34) being adapted such that the hanging member can overlap or partially surround a portion of a ladder rung (100, 101).
4. The device according to any of claims 1 to 3, wherein the wearing member (40) includes - or essentially consists of - a first deformable link the two ends of which are secured to the mast, preferably in the vicinity of both ends (74, 75) of the mast respectively, and the length of which can be higher than the distance separating both points of attachment of the link to the mast.
5. The device according to any of claims 2 to 4, wherein the latching member (24) is a locking member preventing the second hanging member (33), such as a cam clamp lever, from sliding.
6. The device according to any of claims 1 to 5, wherein the bracket (20) includes one or two arms (22, 23) hinged to the mast (21), in particular one or two pivoting arm(s) along one or two pivot axis (axes) (71, 72) which is (are) substantially perpendicular to the longitudinal axis (70) of the mast, especially parallel to the longitudinal axis (73) of the pressing end hanging cross member (50).
7. The device according to any of claims 1 to 6, wherein at least one part of the mast (21) has, in a transverse cross-section, a concavity oriented to the arm(s) (22, 23), wherein at least one part of the mast can have a "U"-shaped transverse cross-section the opening of which is oriented to the arm(s) (22, 23).
8. The device according to any of claims 1 to 7 which includes a member (80) for mutually reversibly attaching both arms (22, 23) of the boom, such as a pin, this attachment member being held integral with the device, in particular integral with the load arm (22), through a second deformable link (81) such as a cablet.
9. The device according to claim 8 which includes a member for latching the member (80) for mutually reversibly attaching the arms, which is preferably integral with - in particular integrated to - the member (80) for mutually attaching the arms.

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