SUSPENDED LIFTING DEVICE WITH EXTENDED ELEMENTS ALLOWING FOR VARIOUS INCLINATIONS

Abstract

The present invention relates to a suspended lifting device intended particularly for transporting essentially long elements. The device comprises a cradle having, at rest, a horizontal receiving surface for such elements (16) which are elongated along a longitudinal direction. Approximately at the edge and in the middle of the cradle along this direction, a lifting arm (20) includes an upright (28) situated in a vertical plane. The lower part of the upright is fixed to the cradle by a connection, and the upper part, extending over the cradle, is provided with a suspension hook (24). The lifting device is notable in that the connection of the lower part of the upright (28) to the cradle includes a pivot (34) which is parallel to the plane of the cradle and which has a locking system providing several angular positions for this upright relative to the plane of the cradle.Applicable in particular to the transport of roofing panels. Figure for the abbreviation: Figure 1.

Description

Title of the invention: SUSPENDED LIFTING DEVICE FOR ELONGATED ELEMENTS ALLOWING FOR DIFFERENT INCLINES Technical field of the invention

[0001] The present invention relates to a suspended lifting device for elongated elements allowing different inclinations of these elements at the point of their placement, for the purpose of their installation. Technological background

[0002] Some construction sites require the lifting, most often with the aid of a crane, of elongated elements previously placed on the ground and resting horizontally there, in order to place them at a height on a roof surface which has an inclination according to the length of these elements, which inclination can vary from one roof to another according to an angle between 5° and 40°.

[0003] In particular, it is known to lift elongated building roofing panels with a crane. These panels are initially laid flat on the cradle of a lifting device equipped with a lifting hook, allowing them to be moved over a roof to be covered, which has a slope along the length of the panels. This enables operators working on the roof to grasp the panels one after the other and position them for fixing to the roof structure.

[0004] As a known method for lifting such panels, pallet lifters are currently used for their transport. The cradle of these lifters consists of two forks attached to the base of at least one upright located in a vertical plane, and the upper part (or the two upper parts, when connected) overhanging the cradle is equipped with a suspension hook. Preferably, the two forks are adjustable in width and are very slightly raised at their ends. However, the gap between the two forks, even when fully extended, rarely exceeds one meter, whereas roofing panels are several meters long, often between six and ten meters.These differences in dimensions pose stability problems and therefore a risk of the load falling during the maneuver between lifting the cradle and bringing it above the roof, near the point where the transported panel is to be installed. Consequently, in practice, the panels are most often transported one by one using the pallet forklift.

[0005] Lifting the panel placed on the pallet lifter using the hook located at the top of the latter, above the center of gravity of the assembly, maintains the cradle and panel in their horizontal position. Operators on the roof must, when it is inclined, grasp the panel which has been transported horizontally and which therefore has an end offset in height due to the slope of the roof, to free it from the cradle and then tilt it in order to position it on the frame.

[0006] This operation requires two operators, one at each end of the panel, who must retrieve the horizontally positioned panel, either by bringing it to 90° from its final position (namely the one in which it is placed in the direction of the slope) while being at the same height on the roof to release the panel from its cradle, or by bringing said panel parallel to the slope with, in this case, an operator who is located at the top of the slope, and who must therefore bend down to catch the panel, and an operator located at the bottom of the slope, who must then catch the panel by raising his arms, then lower it to a height corresponding to the slope to tilt it and place it.

[0007] This operation on panels that are relatively heavy and bulky (their weight ranges from 6 to 20 kg / m² depending on whether they are single or double sheet, or even include insulation sandwiched between the two sheets), with potentially sharp edges, presents problems related to the effort required, the ergonomics of the operation, the time lost, and the risk of accidents due to the mass and inertia of these panels. In particular, for operators working on an inclined plane that can reach 40°, sometimes with gaps between the structural elements, this operation is undoubtedly very delicate.

[0008] It is also known to move building roofing panels from the ground to the area of ​​the roof to be covered using a vacuum lifting beam. This lifting device comprises several pairs of suction cups surmounted by two independent vacuum circuits, two electric vacuum pumps connected to a battery, and a lifting hook. Such a lifting beam is most often used with a radio control system. Due to its complexity, this lifting method has the disadvantage of being very expensive. Furthermore, by its very nature, it can only transport one roofing panel at a time.

[0009] For lifting other elongated elements laid horizontally on the ground and bringing them into position at an angle, in this case wind turbine blades, a known type of lifting device, described in particular by documents EP-A1-2924278 and EP-A1-2623768, comprises a triangular lifting system equipped with a cable, including an upper attachment point that is lifted by the hook of a crane. The other two points of the triangle are fixed to the elongated element, on either side of the vertical line of the hook, to form one side of the triangle parallel to that element.

[0010] A remote-controlled motor of the triangular system winds the cable onto a pulley, thus modifying the geometry of the triangle. In this way, the elongated element is moved longitudinally relative to the vertical axis of the hook, thereby shifting its center of gravity and the element's inclination. This type of lifting device is used particularly for lifting wind turbine blades to fix them at an angle onto the propeller hub.

[0011] However, this type of lifting device presents problems of complexity in its design and operation due to the pivots at the corners of the triangular shape of the lifting system, the cable with its winding hub, and the motor that drives this hub. These moving parts can experience wear and tear and a risk of failure over time. Their complexity leads to manufacturing costs, and they also necessitate the periodic maintenance and inspections required for any lifting system to prevent accidents. Furthermore, the aforementioned lifting devices also only provide for the transport of such elongated elements individually. Presentation of the invention

[0012] The present invention is specifically intended to avoid these problems of the prior art.

[0013] To this end, it proposes a suspended lifting device intended in particular for transport of essentially long elements, such as roofing panels, said device comprising a cradle having at rest a horizontal plane for receiving such elements which are elongated along a longitudinal direction and, substantially at the edge and in the middle of the cradle along this direction, a lifting arm comprising an upright situated in a vertical plane, the lower part of which is attached to this cradle by a connection, and the upper part of which overhangs the cradle is provided with a suspension hook, said lifting device being remarkable in that the connection of the lower part of the upright to the cradle includes a pivot which is parallel to the plane of the cradle and which has a locking system giving several angular positions of this upright relative to the plane of the cradle.

[0014] A first advantage of this device is that it allows the lifting of several elongated elements stacked one on top of the other, to a height of about one meter, instead of the current lifting unit by unit.

[0015] Another advantage of this lifting device is that it allows, in a simple and quick way, to prepare an inclination of the upright relative to the cradle at rest placed horizontally on the ground, to lock this inclination by the locking system, and then to load without difficulty the elongated elements delivered flat horizontally onto this cradle.

[0016] Next, lifting the lifting arm's hook above the cradle's central point by a crane will cause the device to rise, automatically positioning the upright vertically, simply because the center of gravity of the assembly, including the cradle and the supported elements, aligns below the hook. This automatically results in the elements being inclined to the angle determined by the position between the upright and the cradle.

[0017] In particular, for panels used as roof covering, by providing several possible angular positions of the upright relative to the cradle corresponding to different types of roof, the correct inclination of the panels is obtained during lifting and instantaneously, simply by lifting the device, which allows them to be positioned as close as possible to the roof to be covered, parallel to the slope.

[0018] Each operator can then easily slide the top panel of the stack to the side of the stack to lower it to a low height, in order to position it directly on the roof structure. This operation requires little effort, is ergonomic by limiting the movement of the panel on the roof of the building, requires minimal effort, and presents little danger.

[0019] The lifting device for elongated elements according to the invention may further comprise one or more of the following characteristics, which may be combined with each other.

[0020] Advantageously, the cradle includes a longitudinal member which is arranged laterally, in the vertical plane of the upright, on the side of the locations of the elements.

[0021] In this case, advantageously, the longitudinal member has in its central part two parallel plates which are fixed on its sides and which form between them a guide for the base of the upright when the latter is pivoting.

[0022] According to a preferred construction, the two sheets and the base of the upright have aligned holes receiving an axis forming the pivot.

[0023] According to this construction, the two sheets also have, aligned in at least one row in an arc of a circle, holes receiving removable pins which allow the angular position of the upright to be set relative to the longitudinal member.

[0024] Preferably, at least two pins come from each side of the upright in a fitted manner to achieve its angular shimming.

[0025] Advantageously, the width between two successive holes in the row or of each row in the arc of a circle is such that the width between two pins after their insertion into said holes corresponds either to the width of the upright, or to a fraction 1 / 2, 1 / 3 or 1 / 4 of this width.

[0026] According to yet another preferred construction, in the plane of the cradle, on each side of the connection of the upright, the longitudinal member has a fork arranged in a transverse direction.

[0027] In this case, each fork has an adjustable positioning according to the length of the longitudinal member.

[0028] Still in this hypothesis, each end of the cradle has a transverse vertical stop providing a wedge for the ends of the elongated elements.

[0029] In addition, each end of the cradle has in its plane a support base for the ends of the elongated elements.

[0030] Preferably, the vertical stop and the base are formed from the same folded sheet metal.

[0031] Advantageously, the longeron is a tube with a square cross-section and the bent sheet metal is then welded onto an extension consisting of a square tube fitted and mounted to slide into one end of the longitudinal member.

[0032] Even more advantageously, the lifting arm has in its upper part a crossbar which, depending on its length, has different positions for the attachment of the suspension.

[0033] In this latter construction, the cross member is surmounted by a slide formed by a sheet metal whose lower edge has notches distributed along its length.

[0034] In a variant or in association with this latter construction, the cross member is surmounted by a slide formed by a bar bent at three points and thus presenting the shape of an M providing two possible positions for the suspension attachment, one unloaded and the other loaded.

[0035] According to another preferred construction, each fork is equipped with a strap attachment system to hold and secure all the roof covering panels during their transport phase between the ground and the roof to be covered. Brief description of the drawings

[0036] The invention will be better understood and other features and advantages will become more apparent upon reading the following description given by way of example, with reference to the accompanying drawings in which: [Fig.1] is a perspective view of a lifting device according to the invention; [Fig.2] is a side view of this device; [Fig.3] is a rear detail view of the connection of the lifting arm upright to the cradle of this device, said upright being locked in an inclined position; [Fig.4] is a front view of this device showing a cradle inclination of 30° relative to the horizontal; [Fig.5] is a rear view of this device containing a stack of panels with the same 30° inclination; [Fig.6] is a front perspective view of this device open to its maximum length; [Fig.7] is a side view of this device showing a sliding variant; [Fig.8] is another rear view detail of the linkage of the lifting arm upright of this device locked this time in a vertical position, therefore perpendicular to the cradle; [Fig.9] and [Fig. 10] are perspective views, respectively from the rear and front, in which a fork is shown fitted with a panel fixing strap. Description of preferred embodiments

[0037] Throughout the following description, the term "upper" or "top" refers to a cradle of the lifting device placed flat, at rest, on a horizontal surface. The elongated elements will be chosen to be, for example, sheet metal roofing panels. Such panels are generally about one meter wide, with lengths ranging from four to ten meters, most often around six meters, and weigh approximately fifteen kilograms per square meter. These panels typically have longitudinal ribs to improve their strength properties, particularly resistance to bending, torsion, buckling, etc. They may also have surface features such as grooves and raised areas that imitate, for example, tiles or slates.

[0038] Figures 1, 2, and 6 depict a lifting device according to the invention, which device comprises a cradle having a horizontal receiving plane for stacked elongated elements 16. This cradle includes, along a longitudinal direction, a tubular longitudinal member 2 with a square cross-section, positioned on one side of the location of said stacked panels 16. On either side of its midpoint, the longitudinal member 2 receives a fork 4 arranged transversely in a mounting plane on the cradle. A central lifting arm 20 fixed to the midpoint of the longitudinal member 2 allows the entire device to be lifted.

[0039] Each fork 4 is fixed to the longitudinal member 2 by means of a slide 6 comprising a clamping screw 7, allowing adjustment of the longitudinal position of this fork on half of the longitudinal member it equips in order to obtain a spacing between the two forks which allows perfect support of the elongated panels 16 stacked on said forks, against the longitudinal member 2. It is provided that the longitudinal member 2 has a length of six meters, that the spacing between the two forks therefore reaches this value of six meters, so that the cradle perfectly supports panels that can reach ten meters in length as will be described below.

[0040] Each end of the longitudinal member 2 receives an extension 8 consisting of a square tube fitted into that of this longitudinal member, which can slide inside, and a locking pin or screw 17 for locking its longitudinal position. Advantageously, this locking pin or screw 17 cooperates with two of the holes 19 drilled opposite each other, at regular intervals of ten cm, for example, in the upper and lower faces respectively of the sliding extension 8. The outer end of the tube of the extension 8 is further provided with a vertical plate 10 arranged transversely, forming an end stop for the supported panels 16 in order to achieve their longitudinal alignment. Two handles 14 arranged at the top of the outer face of each end plate 10 facilitate straight-line movement of the extensions 8 relative to the stringer 2, when their pins or clamping screws are removed.The usable length of each extension cord 8 should ideally be at least two meters.

[0041] Each end plate 10 is made from a sheet of metal folded inwards at the bottom to form a horizontal base 12 positioned at the level of the mounting surface, i.e., at the level of the upper faces of the forks 4. This is intended to support the ends of the panels 16 in addition to the two forks 4 arranged in intermediate positions. The folded sheet metal 10, which acts as both a stop and a support for the stacked panels 16, is advantageously welded to the end of the extension 8. Alternatively, if it is difficult to make the end 10 from a single folded sheet, the "stop" and "support" parts 12 of the end plate are each made from a sheet of metal, the two parts being welded together at an angle of 90°.

[0042] In this way, with the lifting device placed flat on the ground, most generally in a horizontal position or at least very close to horizontal, the two extensions 8 are prepared to be perfectly positioned to receive the superimposed panels 16 between the end plates 10, ensuring that their center of gravity is aligned with that of the lifting arm 20. The spacing of the two forks 4 is also prepared so as to obtain, with the bases 12 of the end plates 10, supports for the panels 16 which are ideally distributed over the length of the cradle to avoid their deformation.

[0043] The lifting arm 20 includes a cross member with a square cross section 22, the rear end of which is fixed to the upper end of an upright 28 having the same cross section, the cross member 22 thus overhanging the cradle of the device and, if installed, the stacked panels 16 ready to be transported.

[0044] The cross member 22 has a length at least equal to half the width of the panels 16 that can be received on the cradle, i.e. at least fifty centimeters and preferably in the order of sixty to seventy centimeters, and it includes above it a slide 26 formed by a vertically arranged sheet metal which is fixed at its ends to the upper face of the cross member and which has notches 25 distributed along its length on its lower edge. Thus, whatever the total weight of the panels transported relative to the weight of the lifting arm, one of the notches 25 of such a cross member 26 will be located substantially above the center of gravity of the "cradle + panels" assembly (see [Fig. 2]).

[0045] A suspension attachment means 24, for example a ring formed by a steel rod, is engaged in the space under the slide 26 to be lifted by the hook of a crane, after having been adjusted in a transverse position in that of the aforementioned notches which is located overhanging the center of gravity of the "cradle + panels" assembly to be moved, in order to keep a perfect horizontal seat in this transverse direction.

[0046] In a variant shown in [Fig.7], the cross member 22 is surmounted by a slide 50 formed by a round section iron or bar which is bent at three points 51 so as to present the shape of an M thus providing two possible positions for the suspension attachment 24, one when the device according to the invention is unloaded and the other when said device is loaded.

[0047] The upright 28 has in its upper part, on each side along the longitudinal direction, and slightly below the cross member 22, a wide handle 30 which facilitates gripping by an operator, in particular for guidance when dropping the panels 16 from the lifting device, in order to cover the roof.

[0048] At midpoint of its length, the longitudinal member 2 has on each of its two sides a welded guide plate 32, parallel to the longitudinal direction. This plate has a substantially straight lower edge and an upper edge that overhangs in an arc centered on a pivot 34 located just above the longitudinal member. The pivot 34 consists of an axis engaged in a hole through each of the two plates 32 and in a hole provided in the lower part of the upright 28 located between said plates, in order to allow the lifting arm 20 to pivot in the vertical plane with precise guidance between these plates.

[0049] In order to reinforce the strength of these two sheets 32, it is planned to connect them at intervals by means of spacers 44 arranged slightly recessed from the edge in an arc of a circle, at points far from the upright 28 so as not to hinder its pivoting,

[0050] The two plates 32 also have identical holes 36 forming at least one row aligned in an arc with constant spacing, allowing removable pins 42 to be received and for this purpose fitted with handles 40 on the rear side of the upright of the device. The width between two successive holes 36 of the row or of each row in arc of a circle is such that the width between two pins 42 after their insertion into said holes corresponds either to the width of the upright 28, or and preferably to a fraction 1 / 2, 1 / 3 or 1 / 4 of this width so as to multiply the possible angular positions A of the upright 28.

[0051] In this way, an operator selects the angular position of the upright 28 as close as possible to the slope of the roof to be fitted with panels 16, taking into account the possibilities offered by the holes 36, and then engages two pins 42 to lock the rotation of the upright 28 of the lifting arm 20 in both directions. The two removable pins 42 can, if necessary, be positioned, one on one row of holes in an arc and the other on another row of holes. By way of example, [Fig. 3] shows a removable pin 42a to the right of the upright 28, which is fully inserted into its two opposing holes, and a removable pin 42b to the left of said upright, which is only partially inserted.

[0052] For a vertically arranged upright 28 as illustrated in more detail in [Fig.8], after loading the lifting device with a stack of panels 16, the crane lifts it by the ring 24 positioned in a chosen notch of the slide 26. The center of gravity being in the plane of the lifting arm 22, the upright 28 is vertical and the cradle remains in a horizontal plane as illustrated in [Fig.6].

[0053] Figures 4 and 5 show a post 28 which, while the cradle of the lifting device was at rest in a flat, horizontal position, was inclined relative to the plane of the cradle at an angle A corresponding to the angle that the roof to be fitted makes with the horizontal. During lifting, the crane applies a force F to the ring 24 which balances the weight G of the device acting on its center of gravity. This center of gravity, positioned vertically under the ring 24, keeps the post 28 vertical, while the cradle and the panels 16 it carries are then inclined at the angle A formed by this post.

[0054] On the downstream side, the end plate 10 forms a stop preventing the panels 16 from sliding downwards.

[0055] Fig. 6 also shows a maximum extension of the extensions 8, the forks 4 being for this purpose also spread out to the maximum at the ends of the longitudinal member 2. A large load length of the lifting device is obtained, for example of ten meters, the two forks being spread out by six meters, with four supports distributed under the length of the panels 16, consisting of the two forks 4 and the bases 12 of the two end plates 10.

[0056] According to the invention, panels 16, or any other long product, exhibiting significant mass and inertia, can thus be transported and deposited at various inclinations simply by choosing at the beginning of the operation the angular position A of the upright 28. The crane will place them precisely on a roof with the correct inclination A, which greatly facilitates and secures working at height for the operators.

[0057] If necessary, in order to maintain and secure the stack of panels 16 during the transport phase between the ground and the roof to be covered with said panels, each fork 4 is provided with a strap attachment system 52, as shown in Figures 9 and 10. To this end, the free end of the fork 4 is designed in the form of two fingers 53 between which one end of the strap 52, having an axis fixed perpendicular to the strap, can be inserted and thus held in a position desired to be perpendicular to the stringer 2. After wrapping the stack of panels 16, the other end of the strap is attached to the slider 6 by means of a ratchet system, until the stack is perfectly tightened. The strap is released by the operators located on the roof to be covered and can, if necessary, be reused for one of the future transports.

[0058] Advantageously, the top of each fork 4 is provided with a non-stick and scratch-resistant coating designed to protect the lower panel of the stack to be transported. This coating is, for example, in the form of a pad that covers the fork and extends from one longitudinal edge to the other of a support 54 fixed by screws below the fork. The edges of this pad, for example made of a plastic material or of an SBR-type rubber, are attached to the edges of the support 54 by means, for example, of screw / nut / washer devices that pass through holes drilled near the edges of the pad. Thus, the pad can be easily replaced with a new one in case of wear. Such a pad has the advantages of preventing slippage and damage to the load.

[0059] The lifting device according to the invention, simple and economical to manufacture, adapts quickly to equipment of varying lengths to deliver it at different angles. Having no moving parts during lifting and no motor, it has the advantage of being reliable, which reduces the risk of breakdowns, maintenance costs, and the mandatory inspection points required for all lifting equipment.

[0060] The lifting device can be used to carry any type of long element such as roofing panels, or even wind turbine blades, or any other element which, originally placed horizontally in the cradle of the device according to the invention, must be lifted in order to be made available at a predefined angle.

Claims

Demands

1. Suspended lifting device intended in particular for the transport of essentially long elements, such as roofing panels, said device comprising a cradle having at rest a horizontal plane for receiving such elements (16) which are elongated along a longitudinal direction and, substantially at the edge and in the middle of the cradle along this direction, a lifting arm (20) comprising an upright (28) situated in a vertical plane, the lower part of the upright being integral with this cradle by a connection which includes a pivot (34) which is parallel to the plane of the cradle, and the upper part of which overhangs the cradle being provided with a suspension hook (24),said lifting device being characterized in that the connection of the lower part of the upright (28) to the cradle further has a locking system giving several angular positions of this upright relative to the plane of the cradle and each end of the cradle receives a sliding extension (8) the outer end of which is provided with a vertical plate forming a transverse vertical stop (10) providing a wedge for the ends of the elongated elements (16).

2. Lifting device according to claim 1, characterized in that the cradle comprises a longitudinal member (2) which is arranged laterally, in the vertical plane of the upright (28), on the side of the locations of the elements (16).

3. Lifting device according to claim 2, characterized in that the longitudinal member (2) has in its central part two parallel plates (32) which are fixed on its sides and which form between them a guide for the base of the upright (28) when the latter is pivoted.

4. Lifting device according to claim 3, characterized in that the two plates (32) and the base of the upright (28) have aligned holes receiving an axis forming the pivot (34).

5. Lifting device according to claim 4, characterized in that the two plates (32) also have, aligned along at least one row in an arc of a circle, holes (36) receiving pins (42) for setting the angular position of the upright (28) relative to the longitudinal member (28).

6. Lifting device according to claim 5, characterized in that at least two pins (42) come from each side of the upright (28) in a fitted manner to achieve its angular positioning.

7. Lifting device according to claim 6, characterized in that the width between two successive holes (36) of the row or of each row in arc of a circle is such that the width between two pins (42) after their insertion into said holes corresponds either to the width of the upright (28), or to a fraction 1 / 2, 1 / 3 or 1 / 4 of this width.

8. Lifting device according to any one of claims 2 to 7, characterized in that, in the plane of the cradle, on each side of the connection of the upright (28), the longitudinal member (2) has a fork (4) arranged in a transverse direction.

9. Lifting device according to claim 8, characterized in that each fork (4) has an adjustable positioning along the length of the longitudinal member (2).

10. Lifting device according to any one of claims 2 to 9, characterized in that each end of the cradle has a transverse vertical stop (10) providing a support for the ends of the elongated elements (16).

11. Lifting device according to claims 9 and 10, characterized in that the vertical stop (10) and the base (12) are formed from the same folded sheet metal.

12. Lifting device according to claim 11, characterized in that the spar is a tube of square section and the bent sheet metal is then welded onto an extension (8) consisting of a square tube fitted and mounted to slide in one end of the spar (2).

13. Lifting device according to any one of claims 1 to 12, characterized in that the lifting arm (20) has in its upper part a cross member (22) having different positions along its length for the attachment of suspension (24).

14. Lifting device according to claim 13, characterized in that the cross member (22) is surmounted by a slide (26) formed by a sheet metal whose lower edge has notches distributed along its length.

15. Lifting device according to claim 13, characterized in that the cross member (22) is surmounted by a slide (50) formed by a bar bent at three points and thus having the shape of an M providing two possible positions for the suspension attachment (24), one unloaded and the other loaded.

16. Lifting device according to any one of claims 8 to 15, characterized in that each fork (4) is equipped with a strap attachment system (52) to hold and secure all the roof covering panels during their transport phase between the ground and the roof to be covered.

17. Lifting device according to any one of claims 8 to 16, characterized in that the top of each fork is provided with a non-stick and anti-scratch coating intended to protect the lower panel of the stack to be transported.

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