ES2901691T3 - portable lifting device - Google Patents

Abstract

Lifting device (10) comprising: - a cantilever crane (20) comprising a mast (21) and a loading arm (22, 23) - or loading strut - retractable along the mast; - reversible coupling means (30) of the mast with two bars (100, 101) of a ladder; - a closing member (24) of the reversible coupling means; - a member (40) carrying the device on the shoulder; and - a crossbar (50) supporting one of the bars, and in which the carrier member and the crossbar are integral to the mast.

Description

DESCRIPTION

portable lifting device

Technical area

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

State of the art

Many industrial buildings and facilities, particularly fuel-based electricity production facilities, have ladders affixed ("permanently") to the walls, allowing operators to move around the facility or building, for example, to perform maintenance or control operations.

Where these operations require the use of an object, for example a tool or measuring device, and no fixed means of lifting are provided near a ladder, it may be necessary for an operator who has climbed the ladder to lift the suspended object. to a deformable link, such as a rope, along the ladder, or conversely lowers the object suspended from a deformable link, also along the ladder.

The lifting and lowering of the object are even more difficult if the object is bulky, heavy and/or fragile, and it is common that no lifting device capable of facilitating these actions is integrated into the installation.

Therefore, there is a need for a lifting device that can be easily carried and positioned by an operator climbing a ladder.

Patent JPH11159270 describes a separating device for a mobile ladder that can be fixed to two adjacent bars of the ladder by means of fixed hooks and sliding hooks on which the springs rest. The body of the separation device comprises a main portion comprising a set of tubes forming an "H" and arranged to extend along the ladder, "under" the ladder, that is, between the ladder and the wall of a building against which the ladder is supported by the spreader.

The body of the device further comprises a support portion on the wall of the building, 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 allows a ground operator to lift an air conditioning unit "under" the ladder, from the ground on which the ladder rests to a previously fixed support. 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 lifting a load along a ladder that is rigidly fixed to a wall.

This device is bulky, in particular due to the rigid connection between the "H"-shaped main portion and the support portion; therefore, it is not suitable for lifting a load along a ladder cage, within the ladder cage, nor is it suitable for being carried by an operator climbing a ladder, in particular a ladder cage.

This bulky device is also not suitable for being attached to a ladder and then removed from the ladder by an operator standing on the ladder.

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

United States patent application 2016/245019 A1 describes a lifting device comprising the following features: a cantilever crane comprising a mast and a loading arm - or loading strut; means of reversible coupling of the mast with two bars of a ladder; and a support crossbar on one of the bars and in which the crossbar is integral with the mast.

Description of the invention

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

In particular, there is a demand for a portable device for lifting a load along a fixed ladder, which is light, compact, safe to use, adaptable to different types of ladders in terms of diameter and spacing of the bars, portable non-handheld, which can be attached to the ladder quickly and with one hand, to allow an operator wearing the device to climb the ladder, attach the device to the ladder and continue their progression up the ladder safely.

According to the invention, a lifting device is proposed comprising a cantilever crane comprising a mast and a retractable loading arm along the mast, with reversible coupling means (hooking) of the mast with two bars of a ladder , a device carrier member, and a support crossbar on one of the bars, the carrier member and crossbar being integral with the mast.

The reversible coupling means of the mast with two bars of a ladder preferably comprise a first hooking member to a first bar of the ladder (hereinafter called "upper rung"), which is fixed to the mast preferably rigidly, and a second member for hooking to a second ladder bar (hereinafter referred to as the "bottom rung" and substantially parallel to the first ladder rung), which is mounted to be movable with respect to the mast, so that the reversible coupling means are adjustable (deformable), and the reversible coupling means comprise return means of the engaging members towards each other.

In other words and according to another aspect of the invention, a lifting device is proposed comprising:

- a mast having a longitudinal axis;

- a load strut - or load arm - integral with the mast in the vicinity of a first longitudinal end (or upper part) of the mast;

- a device carrier member that is integral with the mast;

- a support piece (on a top bar) integral with the mast, extending transversely (with respect to the longitudinal axis), and carrying (or comprising) a first hooking member (on the top bar) extending to each side of the mast, preferably substantially symmetrical about the longitudinal axis;

- a second hooking member (to the lower bar) that is slidingly mounted with respect to the mast, in the vicinity of a second longitudinal end (or base) of the mast;

- a return member of the second hooking member towards the first hooking member;

and in which the load strut is retractable along the mast, which can go from an extended configuration in which the free end of the load strut extends a first distance from the longitudinal axis, to a retracted configuration in which the free end of the load strut extends a second distance from the longitudinal axis which is less than the first distance.

Each of the latching members may be in the form of a bent elbow, hook or staple-shaped tab, which is adapted/chosen so that the shape and dimensions of each latching member so that the member can overlap (or partially surround) a portion of the length of a ladder rail, to keep the device in contact with the ladder rung.

The invention makes it possible to have, due to the fact that the load strut is separated, a compact device, with a slender and balanced shape, which can be easily handled and manipulated with one hand by an operator who is standing on the ladder and who grasps the device. for the mast, also good for hooking over its shoulder than for sticking out its shoulder, for fixing it to two parallel bars by deformation (extension) of the reversible coupling means, and for separating it from the bars by a manipulation in the reverse direction.

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

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

According to one embodiment, the extension of the reversible coupling means is accompanied by a lengthening 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 coupling means can be obtained, after the second coupling member has been coupled with the lower bar, by means of a 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 force of sufficient traction to overcome the return forces exerted by the return means as well as the frictional forces during the sliding of the second latching member along the mast.

The intensity of this pulling force can be in a range from approximately one Newton (1N) to approximately ten Newtons (10N).

The device comprises a reversible coupling means locking member or device, in particular, a locking member that prevents the sliding of the second coupling member along the mast, such as a cam clamping lever.

The retractable and deployable load stanchion may include one or two arms articulated on the mast, in particular one or two arms pivoting according to one or two pivot axes that are substantially perpendicular to the longitudinal axis of the mast, in particular parallel(s) to the longitudinal axis of the mast. to the longitudinal axis of the support piece.

According to this embodiment, the load strut comprises a draw arm and a load arm. Alternatively, the loading stanchion may comprise a loading arm and a deformable drive, such as a cable, connecting the loading arm to the mast.

This allows the load strut to be retracted by a pivot of the arm (or arms) relative to the mast.

For this particular purpose, at least part of the mast may have, in cross section, a concavity that faces the arm(s) of the load strut. This concave part can thus receive a part of the arm, in the position of retraction of the load strut, which at the same time guarantees the rigidity of the mast.

The device may comprise a mutually reversible fixing member for the two arms of the loading strut, such as a pin, which holds this fixing member integral with the device, in particular integral with the loading arm, by a second deformable joint just like a wire.

The device may comprise a closing member of the mutually reversible fixing member of the two arms, which can be integral to - in particular integrated into - the mutual fixing member of the arms, which is this closing member, for example , which is constituted by a ball from a pin to a safety ball.

The device may further comprise a shackle that is fixed in the vicinity of the free end of the load strut and/or a carabiner used to suspend a hoisting pulley from the shackle and/or the load strut, the pulley which may include a brake for a lifting cable or strap that is attached to the pulley.

The invention allows to obtain a compact and light lifting device that is easy to carry on the shoulder. In particular, the dimensions of the parts of the lifting device and the materials that are chosen for its manufacture can make it possible to obtain a device whose mass is less than 5 or 10 kilograms, which allows the device to lift a load of several tens of a kilogram.

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

- carry the device on the shoulder, in front of the body;

- climb a ladder to the vicinity of a platform that can be provided in the vicinity of the top of the ladder;

- engaging the movable latching member below a "lower" ladder bar that extends substantially at the level of the operator's waist;

- holding the device with one hand by the mast, which causes the reversible coupling means to extend and then engage the fixed coupling member on an "upper" bar of the ladder, which bends the mast against this bar;

- lock the reversible coupling means; then the operator grabs onto the platform:

- unfold the bracket crane;

- couple the loading arm in the peg by the pin to the ball; Y

- Suspend a lifting pulley from the loading arm.

Rather, a method of removing the device may comprise the following operations:

- separate the lifting pulley from the loading arm;

- uncouple 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 stands on the ladder in front of the device:

- place the carrying member on the shoulder;

- release the reversible coupling means;

- hold the device with one hand by the mast, which causes the reversible coupling means to extend, then release the fixed hooking member of the "upper" bar of the ladder, moving the upper part of the mast away from this bar; later

- release the mobile hooking member under the "lower" bar of the ladder.

Other aspects, characteristics and advantages of the invention appear in the following description that refers to the attached figures and illustrates, without any limiting character, the modalities of the invention.

Brief description of the figures.

Figure 1 illustrates, in perspective view, a lifting device whose load strut has been deployed.

Figure 2 is a perspective view from another angle of the device illustrated in Figure 1.

Figure 3 illustrates, in side view, the lifting device illustrated in Figures 1 and 2.

Each of Figures 1 to 3 also includes, in the lower part of the figure, a section illustrating an end position of the mobile lower member for hooking the device to a ladder bar.

Figure 4 illustrates, in side view, the device illustrated in Figure 3 in a loading stanchion retraction configuration which is obtained by tilting the loading stanchion arms along the mast of the device. Figure 5 illustrates, in top view, the device illustrated in Figure 3 and is a view along V of Figure 3.

Figure 6 schematically illustrates a coupling operation of a lower hooking member of the lifting device with a lower ladder bar, and Figure 7 schematically illustrates a subsequent coupling operation of an upper hooking and support member of the lifting device with another bar extending above the bottom bar.

Figure 8 schematically illustrates an object lifting operation using a lifting device that is attached to the top two bars of a "non-pop-up" ladder, that is, the top of which extends to the level of a platform on which an operator can stand, and Figure 9 schematically illustrates an object lifting operation using a lifting device that is attached to two successive bars of a "pop-up" ladder, that is, the top of which extends above a platform on which an operator can stand.

Detailed description of the invention

Unless otherwise indicated explicitly or implicitly, structurally or functionally identical or similar elements or members are designated by identical references in the various figures.

With reference to Figures 1 to 9, the device 10 is used to hoist a load marked 104 in Figures 8 and 9, which is suspended from a deformable link such as a rope, along a fixed ladder 102 comprising at minus two bars 100, 101 which overlaps the device 10 for this purpose is temporarily fixed.

The device 10 comprises a cantilever crane 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 load strut along the mast.

For lifting a load, pulling is done by an operator with a rope (not shown) which is attached to a pulley (not shown) which is suspended from the load strut 22, 23.

For this purpose, the device may comprise, as illustrated in Figures 1 to 3, a shackle 90 which is fixed in the vicinity of the free end 25 of the load strut and a carabiner which is suspended from the shackle and which supports the pulley of the loader. elevation.

The pulley may comprise a brake for the hoist rope which engages the pulley.

In the embodiments illustrated in Figures 1 to 5, the mast 21 consists of a bar, the cross section of which is U-shaped.

The upper arm 23, which serves as a brace, is fixed to the upper end 74 of the mast 21, between the wings of the U-shaped profile 21, by means of a pivot with axis 72 perpendicular to axis 70.

The lower arm 22, which serves as a load arm and on whose free end 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 means of a pivot axis d '71 parallel to axis 72.

The arms 22, 23 can thus partially extend between the wings of the U-shaped section 21, along this section, when their respective free ends have been mutually separated, as illustrated in Figures 4, 6 and 7.

Each arm 22, 23 respectively comprises a yoke 26, 27 (see Figure 4) which is pierced with a hole for the passage of a ball pin 80 (see Figure 3 in particular) serving as a reversible mutual locking member for arms 22, 23.

To deploy the load strut, the operator rotates the arms 22, 23, from their retracted position along the mast to a deployed position illustrated in Figures 1 to 3 and 5, a position in which the holes for 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 does not engage in the holes of the yokes, the pin is connected to one of the pieces of the device by means of a deformable joint 81 (see Figure 3); the pin, for example, is connected, by the joint 81, to another yoke 28 which is provided on the arm 22.

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

The device 10 comprises a support beam 50 (see Figure 2 in particular) for support and hooking on a ladder bar, which is rigidly fixed to the arm 21, in a substantially "central" portion of the mast, that is, in a intermediate portion between the upper 74 and lower 75 ends of the mast.

The crosspiece 50 extends according to a transverse axis 73 (with reference to the axis 70) which is parallel to the axes 71, 72 of rotation of the arms.

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

The crosspiece 50 comprises - and is essentially made up of - three flat wings (see Figure 4 in particular) elongated along the axis 73:

- a first wing 34 serves to fix (rigidly) the crossbar 50 to the mast 21;

- a "central" wing 31, which forms a right angle with the wing 34 to extend in a plane perpendicular to the axis 70 of the mast; Y

- a third wing 32, which forms an obtuse angle with the wing 34, serves to retain the crossbar 50 (and the device 10) that engages with the bar 100 as long as the crossbar rests on this bar.

The central wing 31 can serve as a support surface on a top ladder bar 100, when the diameter of this bar is less than or equal to the width of the wing 31. Otherwise, the supporting and hooking crossbar 50 rests on the bar. 100 for its two lateral wings 32 and 34.

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

As illustrated in Figure 2, the central portion of the latching wing 32 is provided with a cutout 32a which serves to reduce the mass of the cross member. Consequently, the hooking wing 32 comprises two projecting tabs that extend respectively at the two longitudinal ends of the crossbar 50, such that these hooking tabs extend on both sides of the mast.

As illustrated in Figures 2 and 3 in particular, the crossbar 50 is in the form of a staple, the concavity of which is directed towards the lower end 75 of the mast.

The device 10 comprises a second latching member 33 with a second ladder bar 101 parallel to the first ladder bar 100, which is rigidly attached to a sheet 29 which is slidingly mounted with respect 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 latching member 33 is movable (sliding) with respect to the mast 21.

The movable latching member 33 extends to the side of the crossbar 50 and has an upwardly enlarged staple shape, the concavity of which is directed towards the upper end 74 of the mast and towards the crossbar 50.

As illustrated in Figures 2 to 4, the mobile hooking member 33 is formed by three flat wings parallel to the axis 73, and has a cross section identical to that of the crossbar 50.

The shape and dimensions of the crossbar 50 and of the movable hooking member 33 are adapted so that each of these pieces 33, 50 can partially surround a longitudinal portion of a ladder bar: the crossbar 50 overlaps part of a portion longitudinal portion of the upper bar 100, and the movable latching member 33 surrounds the bottom of a longitudinal portion of the lower bar 101 (see Figures 3 and 7 to 9).

The enlarged shape of crossbar 50 and movable latching member 33 allows them to accommodate bars of different diameters by self-centering.

The device 10 also comprises a return member that is constituted by a spring 35 (see Figures 6 and 7), a first end of which is fixed to the sheet 29 and a second end of which is fixed to the mast, so that this spring is stressed in traction when the movable latching member 33 moves away from the lower end 75 of the mast, as schematically illustrated in Figures 1 to 3 and 6.

The spring 35 serves to return the sheet 29 and the member 33 towards the upper end of the mast, that is, towards the crossbar 50.

Spring 35 allows the device to stand on its own on the scale when not locked.

In addition, the spring 35 also serves to auto adapt the support and latch members (31 to 34) as a function of the distance to the center of the ladder bars.

Sheet 29 is perforated with a longitudinal opening through which extends a rod which is fixed to the core of the mast and which is integral with a lever 24 with pivoting cam 36 capable of pressing on sheet 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 engagement member 33 with relative to the mast.

The crossbar 50 and its supporting and latching members 31, 32, 34 can be positioned eccentrically on the mast, that is, closer to the lower end 75 of the mast than to the upper end 74, so that the load-bearing strut of the device extends along above the bearing 103 (or platform illustrated in Figures 8 and 9), in particular when the ladder stops at the level of the bearing as illustrated in Figure 8, thus allowing the operator in charge to retrieve the object 104 and which is located in the bearing, to grab the object more easily.

The device 10 further comprises a strap 40 for carrying the device (see Figure 7), whose two ends 41, 42 are fixed to the mast, respectively, in the vicinity of the two ends 74, 75 of the mast.

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

The device can be used as follows:

- an operator carrying the device 10 (whose load strut retracts) on the shoulder (for example, the left shoulder) by the strap 40 climbs a ladder to a certain height, the device rests on the shoulder, between the operator and the scale;

- the operator standing with his hand that does not correspond to the shoulder carrying the device (for example, his right hand) holding/hanging from a ladder bar, separates his opposite hand (his left hand) from the ladder, grabs the device by its pole, with one hand (with your left hand), which keeps the strap on your shoulder to prevent an accidental fall of the device;

- the operator engages the lower movable latching member 33 of the device under a ladder bar 101 that extends, for example, slightly above his belt, while keeping (with his left hand) the mast tilted as illustrated in Figure 6, ie, the upper end 74 of which extends from the ladder bars, between the ladder and the operator's torso;

- the operator then exerts (with his left hand) a vertical upward pull on the mast illustrated in Figure 6 by the load strut 95, which is sufficient to cause the extension of the spring 35 and the sliding of the blade 29 and from the lower latching member 33, with respect to the mast, to the configuration illustrated in Figure 6 in which the upper latching members 31, 32 extend above the bar 100 protruding from the bar 101 with the that member 33 engages;

- in this configuration, the operator places (with his left hand), through a pivoting movement illustrated in Figure 6 by the load strut 96, the mast against the rungs of the ladder, then releases his pulling force ( 95) so that the coupling members 31, 32, 34 engage with the bar 100 and that the crosspiece 50 rests on this bar;

- the operator can then release the device mast, slide the strap along his (left) arm and block (with his left hand) the sliding of the blade 29 acting on the lever 24 with the cam 36; - the operator can then continue his progression on the ladder to a platform near the top of the mast (and the ladder), then unfold the loading strut of the cantilever crane, lock the mutual set of arms 22, 23 by means of the ball pin, attach a carabiner with a pulley to the shackle suspended from the load strut, and attach a lifting rope to the pulley.

A second operator positioned at a lower level, at the bottom of the ladder, can lift a load suspended from the hoist rope.

Once the load is placed on the platform, the operator can proceed, in reverse order as above, with the reverse operations to retract the load strut, reattach the device strap to the shoulder, and then detach the device from the platform. ladder.

Claims (9)

i. Lifting device (10) comprising: - a cantilever crane (20) comprising a mast (21) and a loading arm (22, 23) - or loading strut - retractable along the mast; - reversible coupling means (30) of the mast with two bars (100, 101) of a ladder; - a closing member (24) of the reversible coupling means; - a member (40) carrying the device on the shoulder; Y - a support crossbar (50) on one of the bars, and in which the carrier member and crossbar are integral to the mast. 2. Device according to claim 1, in which the means (30) for reversible coupling of the mast with two bars of a ladder comprise a first member (31, 32, 34) for hooking to a first bar (100) of a ladder, which is fixed to the mast, a second member (33) for hooking to a second bar (101) of a ladder that is mounted mobile with respect to the mast, and means (35) for returning the members (31 to 34 ) latching towards each other. 3. Device according to claim 1 or 2, in which: - the mast has a longitudinal axis (70); - the loading arm - or loading strut - is integral with the mast in the vicinity of a first longitudinal end (74) of the mast; - the support crossbar (50) extends transversely (73) with respect to the longitudinal axis (70), and carries (or comprises) a first member (31, 32, 34) for hooking to a first bar (100) of a ladder that extends on both sides of the mast, preferably substantially symmetrically with respect to the longitudinal axis (70); - the device comprises a second hooking member (33) for hooking to a second ladder bar (101) parallel to the first ladder bar, said second hooking member (33) being mounted slidingly with respect to the mast, in the vicinity of a second longitudinal end (75) of the mast; - the device comprises a member (35) for returning the second hooking member (33) to the first hooking member (31, 32, 34); - the retractable load strut can pass from a deployed configuration in which the free end of the load strut extends a first distance from the longitudinal axis (70), to a retracted configuration in which the free end of the load strut extends extends a second distance from the longitudinal axis (70) that is less than the first distance; the shape and dimensions of each latch member (31 to 34) are adapted so that the latch member may overlap or partially surround a portion of a ladder bar (100, 101). Device according to any one of claims 1 to 3, in which the carrier member (40) comprises - or is essentially constituted by - a first deformable joint, the two ends of which are fixed to the mast, preferably respectively in the vicinity of two ends (74, 75) of the mast, and whose length can be greater than the distance that separates the two fixing points of the union to the mast. Device according to any of claims 2 to 4, in which the closing member (24) is a blocking member that prevents the sliding of the second latching member (33), such as a cam clamping lever . Device according to any one of claims 1 to 5, in which the cantilever crane (20) comprises one or two arms (22, 23) articulated on the mast (21), in particular one or two arms pivoting according to one or two pivot axes (71, 72) which is (are) substantially perpendicular(s) to the longitudinal axis (70) of the mast, in particular parallel(s) to the longitudinal axis (73) of the crossbar (50) support and hook. Device according to any of claims 1 to 6, in which at least part of the mast (21) has, in cross section, a concavity oriented towards the arm(s) (22, 23), at least one part of the mast can have a "U" shaped cross-section whose opening is oriented towards the arm(s) (22, 23). 8. Device according to any one of claims 1 to 7 comprising a member (80) for mutually reversible fixing of two arms (22, 23) of the load strut, such as a pin, this fixing member remains integral with the device, in particular integral with the loading arm (22), by a second deformable link (81) such as a cable. Device according to claim 8, comprising a closing member of the reversible mutual fixing member (80) of the arms, which is preferably integral - in particular, integrated with - the mutual fixing member (80). of the arms.