EP2397435A1 - Joining device to secure the link between lifting equipment and a piece - Google Patents

Abstract

The device (1) has a connection element (2) partially encased in a cavity (5) formed in an element (9). A load limiting element (6) is inserted in a longitudinal housing (7) formed in a wall of the element and the connection element. The limiting element is configured so as to be broken under an overloading effect of a part to move the connection element at a distance (delta), in a direction opposite to a lifting direction, from an operating position to non-operating position. The connection element is prevented from rotation and rotated freely in the cavity in respective positions.

Description

The present invention relates to a connecting device for connecting a lifting tool and a workpiece.

In general, in conventional lifting areas encountered in such diverse sectors as the building industry, it is known to use a device such as a swivel to ensure the connection between one end of a tool of lifting and a piece to lift. Part of the swivel to which the workpiece is attached is provided with a freedom of rotation whose function is to provide a degree of freedom in rotation to the workpiece during its lifting and during its movement.

For example in the field of the aircraft industry, for assembling structures such as the fuselage or wing, devices such as a swivel or a shackle, or an assembly between various shackles and / or swivels are also used for ensure the connection between the lifting equipment and a workpiece to be lifted and moved to a specific location.

In general, a problem can arise when the swivel is subjected too often to loads exceeding the load threshold tolerated by the tool. The various parts constituting all the lifting equipment are then weakened. Fragile areas can then become the seat of crack initiation, which may eventually lead to breakage of the lifting equipment.

Also generally in the field of lifting, in order to ensure the safety and validity of the lifting equipment, it is imperative to carry out a periodic check of the equipment to detect if the latter has an anomaly. But this control is usually not instantaneous or continuous and the occurrence of an overload is not detected immediately.

It is therefore impossible for the operator to check or detect whether a lifting tool has been weakened or not by one or more load overshoots. In addition, it is also not immediate to know the frequency use of tooling in overload situations to evaluate the risk of rupture.

Therefore, these periodic checks do not provide a satisfactory guarantee of safety in the event of an abnormal event not detected.

In addition, a tool may no longer be equipped with parts that conform to the original parts while maintaining a perfectly functional appearance at first glance.

The parts thus replaced during poor maintenance do not guarantee the same resistance to the lifting force and can make the use of such tools dangerous.

The present invention aims to provide a control of safety and validity of the tool more efficient and safer against the risk of breakage of a swivel lifting equipment during the handling operation.

In particular, it aims to be able to detect the overflow of the first use under overload conditions to avoid continuing to use weakened swivels.

The invention proposes to integrate a load limiter element directly into the junction device which, in the event of an overflow, will allow on the one hand to indicate the overflow of the load and on the other hand to make said connecting device unusable, obliging the user to maintain the junction device.

Another object of the invention is to provide a means of traceability which makes it possible to indicate the state of the lifting tool, in particular the last date of inspection, maintenance, and possibly the replaced parts.

For this purpose, the invention relates to a connecting device for connecting a lifting tool to a workpiece, said device comprising a first element able to receive an end of said lifting tool, a second element having a first end provided with a mounting face on the opposite end of said first element, and a connecting element preferably having a T-shape for connecting with said workpiece, said connecting element being partially fitted into a correspondingly shaped cavity formed in said second element.

According to the invention, said device comprises a load limiter element inserted in a longitudinal housing made diametrically in the wall of the cavity of said second element and in the connecting element, said load limiting element being configured so as to be able to break under the effect of a determined overload of the workpiece, causing displacement of a distance δ of said connecting element along a lifting axis in a direction opposite to the lifting direction, of a so-called operating position in which said element link is locked in rotation in the cavity to a so-called non-operating position in which said connecting element is free to rotate in the cavity.

Preferably, said first and second elements and said connecting element are arranged coaxially along the lifting axis.

• ledit élément de liaison comporte une tête et un axe de montage, ledit axe étant pourvu d'un filetage externe sur au moins une partie de sa surface externe joignant son extrémité à une surface inférieure du deuxième éléments lorsque ledit dispositif est en position dite de fonctionnement, un trou de la pièce étant pourvu d'un filetage complémentaire dudit filetage externe,
• le dispositif comporte un moyen de blocage logé dans un logement aménagé dans la paroi de la cavité dudit deuxième élément, ledit moyen coopérant avec un évidement réalisé sur la paroi de l'axe de montage étant apte à bloquer en rotation ledit élément de liaison dans la cavité par rapport au deuxième élément,
• le dispositif comporte une bague à usage unique destinée à venir sertir autour de la paroi extérieure du deuxième élément, ladite bague étant positionnée de telle sorte que les accès auxdits logements dans lesquels sont reçus respectivement ledit élément limiteur de charge et le moyen de blocage soient scellés par ladite bague,
• le dispositif comporte une rondelle interposée entre la deuxième extrémité du deuxième élément et la pièce, ladite rondelle étant serrée sur l'axe de montage, comportant une face supérieure fixée sur la deuxième extrémité du deuxième élément et une face inférieure prenant appui sur la pièce lorsque ladite pièce est fixée sur l'axe de montage.

In various particular embodiments of the connecting device for connecting a lifting tool and a workpiece, each having its particular advantages and likely many possible technical combinations:

• said connecting element comprises a head and an axis of assembly, said axis being provided with an external thread on at least a part of its external surface joining its end to a lower surface of the second element when said device is in said operating position a hole in the part being provided with a thread complementary to said external thread,
• the device comprises a locking means housed in a housing provided in the wall of the cavity of said second element, said means cooperating with a recess formed on the wall of the mounting pin being able to lock in rotation said connecting element in the cavity with respect to the second element,
• the device comprises a disposable ring intended to be crimped around the outer wall of the second element, said ring being positioned such that the accesses to said housings in which said load limiting element and the locking means are respectively received are sealed by said ring,
• the device comprises a washer interposed between the second end of the second element and the part, said washer being clamped on the axis of mounting, having an upper face fixed on the second end of the second element and a lower face bearing on the workpiece when said workpiece is fixed on the mounting axis.

Advantageously, the device comprises an indicator of the breaking of said load limiting element able to emit an audible or visual alarm signal.

According to the invention, said rupture indicator may be a visual indicator consisting of a colored band surrounding the outer wall of the mounting pin, said strip being positioned on the mounting axis so that it is made visible by the displacement of said connecting element by a distance of 8 from the so-called operating position to the so-called non-operating position.

Advantageously, said first end of the second element is provided with a rotational mounting face on the opposite end of said first element to avoid subjecting the part to a gyratory effect.

• en figure 1: une vue en coupe d'un dispositif de jonction pour assurer la liaison entre un outil de levage et une pièce selon l'invention;
• en figure 2: une vue éclatée en coupe du dispositif de jonction selon l'invention;
• en figure 3: une vue du dispositif de la figure 1 et 2 dans laquelle ledit dispositif est en position dite de hors fonctionnement ;
• en figure 4: une vue en coupe selon AA de la figure 1 dans laquelle le moyen de blocage est montré hors du logement;
• en figure 5: une vue en coupe d'une variante du moyen de liaison avec la pièce du dispositif de jonction de l'invention de la figure 1.

Other features and advantages of the invention will become apparent on reading the following description of non-limiting exemplary embodiments of the invention with reference to the drawings which represent:

• in figure 1 : a sectional view of a connecting device to ensure the connection between a lifting tool and a part according to the invention;
• in figure 2 an exploded sectional view of the connecting device according to the invention;
• in figure 3 : a view of the device of the figure 1 and 2 wherein said device is in the so-called off-function position;
• in figure 4 : a sectional view according to AA of the figure 1 wherein the blocking means is shown out of the housing;
• in figure 5 : a sectional view of a variant of the connecting means with the part of the junction device of the invention of the figure 1 .

The purpose of the joining device of the present invention is, on the one hand, to ensure a conventional connection between a lifting tool and a workpiece such as a swivel, and on the other hand to offer a maximum guarantee of safety and security. validity of this junction device.

The general concept of the invention is based on an automatic monitoring of the use of the connecting device in the event of overflow via via a load limiter element integrated directly into the structure of the device.

The present invention also seeks to limit or even prohibit the use of the junction device when it has been subjected to an overload case.

It is also intended to provide a means of traceability on the state of the lifting tool and the connecting device.

An embodiment of a connecting device according to the invention meeting these criteria is represented on the figure 1 . The figure 2 is an exploded view of the figure 1 to better describe the different elements constituting the device.

The junction device 1 is composed of an assembly of elements intended to ensure the connection between the lifting tool and the workpiece. Tooling and the part are not represented on the figures 1 and 2 .

This assembly comprises a first element 8 provided with means for receiving one end of the lifting tool, a second element 9 having a first end provided with a mounting face on the opposite end of the first element 8, and a connecting element 2 preferably having a T-shape comprising a head 3 and a mounting pin 4 to ensure the connection with the workpiece.

The head 3 and a part of the mounting pin 4 are partially received in a corresponding shaped cavity 5 made in the second element 9 and trapped in the cavity.

The first 8 and second elements 9 and the connecting element 4 preferably have a shape of revolution and are arranged coaxially along a lifting axis 12.

On the figure 1 is shown an example of first element 8 provided with a connection means with the end of the lifting tool. It is a ring, it can also be a hook or any other means of attachment.

To exercise the conventional function of a swivel, the second element must be rotatable about an axis which is the lifting axis 12 relative to the first element.

For this, the first end of the second element 9 is provided with a rotational mounting face on the opposite end of the first element 8.

This first end has a shape adapted to engage in a housing 16 arranged at the end of the first element 8.

The figure 2 shows a circumferential groove 15 is formed on the outer wall of the first end, the profile of the wall of the groove and the profile of the inner wall of the housing 16 cooperate together to receive balls 11 between the walls, thus conferring second element 9 rotational mobility around a point which is on the lifting axis relative to the first element 8.

The T-shaped connecting element 2 is trapped in the cavity 5 of the second element 9 and it is not free to rotate in the cavity due to the presence of a load limiter element 6 which eliminates this degree of freedom.

The load limiting element 6 is inserted into a longitudinal housing 7 made diametrically in the wall of the cavity 5 of the second element through the mounting axis 4 of the connecting element.

The axis of this housing is perpendicular to the mounting axis 4, that is to say also perpendicular to the lifting axis. 12.

The head 3 and the mounting shaft 4 of the second element 9 are partially held in the cavity only by the load limiting element, so that when a part is fixed on the mounting axis, its load is entirely supported by the load limiting element 6.

Therefore, when the load limiting element 6 is subjected to a workpiece having a load greater than a predetermined threshold value for the load limiting element. The latter breaks in three parts under the effect of the overload of the part fixed on the end of the mounting pin 4, causing a displacement of a distance 8 of the connecting element 2 along the axis of lifting in a direction opposite to the lifting direction and then releasing the rotation of the connecting element 2 in the cavity 5.

The connecting element 2 then moves from a so-called operating position in which it is locked in rotation in the cavity 5 to a so-called non-operating position in which it is free to rotate in the cavity 5.

The displacement of the connecting element 2 is stopped when the lower face 13 of the head 3 abuts against the upper face 14 of a recess of the cavity 5.

The figure 3 represents the junction device in the so-called out-of-operation position.

The junction device of the present invention is particularly suitable in the case of a specific use where the connection with the workpiece is performed by direct screwing of the axis 4 on the workpiece.

The axis 4 then comprises an external thread on at least a portion of its outer surface joining its end to a lower face of the second element 9, a hole in the part being provided with a thread complementary to said external thread. The screwing of the axis 4 is made by turning the element 9.

In this case, when the device 1 is in the so-called off-operation position, it is no longer possible to disengage the axis 4 of the part by simply unscrewing the element 9.

To make it possible to remove the axis 4 of the part, it is necessary to act on a blocking means located in a housing 7 arranged in the wall of the cavity 5 of the second element 2 which makes it possible to block in rotation the axis 4 in the cavity and allows the unscrewing of the axis 4 by turning the element 9.

The figure 4 shows in detail the locking means for locking the axis 4 in rotation in the cavity. It comprises a pressure screw 19 adapted to exert pressure on a stop 21 having a rounded shape via a spring 20 compressed between the screw and the stop, so that a portion of said stop 21 is projecting at the end a housing 18 opening on a recess 22 formed on the wall of the axis 4.

This recess 22 is machined so as to have a profiled shape cooperating with the portion of the abutment 21 as a protrusion, so that the function of the rotational locking is activated only in a direction of unscrewing of the axis 4 relative to the piece and not insured in the direction of screwing.

The recess has substantially an S shape on the figure 4 when the second element rotates in the unscrewing direction, it also drives the axis 4 in the same direction by contact between the inner wall of the cavity and the outer surface of the mounting shaft until the 'one of the two corners of the recess 22 having a steep slope comes into abutment against the projecting portion of the stop 21, thereby blocking the axis 4 in this position. On the contrary, in the direction of the screwing, the recess 22 of the axis 4 always has the corner having a gentle slope facing the protruding part of the abutment, so that the axis 4 can not be locked in rotation by the abutment. and it remains free to rotate in the cavity. Therefore, the junction device of the present invention can no longer be screwed and reused after being overloaded, it must necessarily be returned to the maintenance circuit.

The device comprises a disposable ring 25 intended to be crimped around the outer wall of the second element 9, advantageously this ring is positioned in such a way that access to the housings 7, 18 in which the load limiting element is respectively received. 6 and the locking means are sealed by the ring 25.

Accessing the housing 18 to actuate the locking means and / or to remove the remaining parts of the load-limiting member has the effect of destroying the ring 25. The destruction of this ring indicates that the device must be returned in the maintenance circuit and no longer be used.

Advantageously, on this ring are written control information such as the date of last verification, or maintenance, which allows one hand to authenticate the ring and secondly allows the user to quickly check the status maintenance of the connecting device, lifting equipment. In particular the information on the ring allows the user to know if parts constituting the tool have been replaced during maintenance.

Thus it is impossible on the one hand to remove the axis 4 of the raised part without destroying the ring in order to access the housing 18 to lock in rotation the axis 4 in the cavity. In addition, the protruding portion of the abutment 21 cooperates with the shape of the recess so as to prohibit reassembly on a part, therefore the use of the connecting device after having been subjected to an overload.

In all cases, the junction device requires maintenance to replace the load limiting element 6, and to do this a disassembly of the device is necessary.

Advantageously, the device comprises an indicator that emits an audible or visual alarm signal to indicate that the load limiting element has acted and that the connecting device requires maintenance.

The device illustrated on the Figures 1 to 5 comprises a visual indicator constituted by a colored band 29 surrounding the outer wall of the axis. This band is positioned on the axis 4 so that when the load-limiting element has not triggered, it is invisible because of the wall of the cavity 5.

When the load limiting element has tripped under the effect of an overload, causing a displacement of the connecting element 2 by a distance 8 in the direction opposite to the lifting direction, this displacement then renders the colored band 29 visible.

Advantageously, to avoid friction by direct contact between the lower surface 28 of the second element and the workpiece, the device comprises a washer 26 interposed between the second end of the second element 9 and the workpiece, said washer being clamped on the shaft 4, having an upper face 27 fixed to the lower face 28 of the second end 9 and a lower face 40 bearing on the workpiece when said workpiece is fixed on the axis.

The Figures 1 to 4 have a junction device 1 specific to the need to lift parts by being screwed directly into the room by means of the axis 4.

According to a variant of the invention of the connecting means of the junction device with the part, the axis 4 is provided with an interchangeable connecting element 34 which can be a shackle, a hook or a ring which is illustrated on the figure 5 the axis 4 is screwed directly onto the connecting element.

The interchangeable connecting element 34 comprises a portion 33 provided with a hook or a ring and a portion 30 having a hole 37 provided with a complementary thread of the external thread of the axis 4, this hole being intended to receive said axis by screwing effect.

In this variant of the connecting means, when the connecting device is subjected to an overload, as in the case where the connecting element is fixed by screwing in the part to be lifted, the load limiting element 6 breaks in three. parts under the effect of the overload causing displacement of a distance 8 of the connecting element 2 along the lifting axis in a direction opposite to the direction of lifting and then releasing the rotation of the connecting element 2 in the cavity 5. The connecting device is then in a position said to be out of operation which requires maintenance. As in the first embodiment of the invention, the element 34 can no longer be dismantled by simply unscrewing the axis, it is then necessary to completely disassemble the junction device if the operator wishes to change the means of link for another operation. In addition, the mounting axis can not be reassembled on another connecting element, it is necessary to perform maintenance on the junction device.

Advantageously, a locking means is provided to reinforce the attachment of this connecting element 34 to the function device. To do this, a housing 31 is formed in the mounting axis 4, this housing being adapted to receive an axis such as a pin. The portion 30 comprises a housing 35. This connecting element 34 is fixed on the mounting pin 4 by passing the pin in the housing 31 provided for this purpose and in the housing 35.

It is also possible to control this interchangeable connecting element by limiting access to the housing 35 by means of a destructible crimped ring 32.

Claims (10)

Connecting device (1) for connecting a lifting tool to a workpiece, said device comprising a first element (8) able to receive an end of said lifting tool, a second element (9) having a first end provided with a mounting face on said first element (8), and a connecting element (2) for connecting with said workpiece, said connecting element (2) being partially fitted in a corresponding shaped cavity (5) in said second element (9), characterized in that said device comprises a load-limiting element (6) inserted into a longitudinal housing (7) formed in the wall of said second element (9) and of the connecting element (2). ), said load limiting element (6) being configured so as to be able to break under the effect of a specific overload of the workpiece, causing a displacement of a distance δ of said connecting element (2) according to the lifting pin (12) in a direction opposite to the lifting direction, of a so-called operating position in which the said connecting element (2) is locked in rotation in the cavity (5) towards a so-called non-operating position wherein said connecting element (2) is free to rotate in the cavity (5). Device according to claim 1, characterized in that said connecting element (2) comprises a head (3) and an axis of assembly (4), said axis (4) being provided with an external thread on at least a part of its outer surface joining its end to a lower face of the second element (9) when said device is in said operating position, a hole in the part being provided with a thread complementary to said external thread. Device according to claims 1 and 2, characterized in that the device comprises a locking means housed in a housing (7) arranged in the wall of the cavity (5) of said second element (2), said means cooperating with a recess ( 22) made on the wall of the mounting pin (4) being adapted to lock in rotation said connecting element in the cavity relative to the second element. Device according to claim 3, characterized in that said locking means comprises a pressure screw (19) adapted to exert pressure on a stop (21) having a rounded shape via a compressed spring (20), so that a portion of said abutment (21) protrudes at the end of a housing (18) opening on said recess (22) of the mounting pin (4). Device according to claim 4, characterized in that the device comprises a disposable ring (28) intended to be crimped around the outer wall of the second element (9), said ring being positioned in such a way that access to said housing ( 7, 18) in which respectively said load-limiting member (6) is received and the locking means are sealed by said ring (25). Device according to one of claims 3 to 5, characterized in that said recess (22) has a profiled shape cooperating with the portion of the abutment (21) in groove, so that the function of the blocking is activated only in the direction of unscrewing of the mounting pin (4) relative to the workpiece. Device according to one of claims 1 to 6, characterized in that the device comprises a washer (26) interposed between the second element (9) and the workpiece, said washer being clamped on the mounting shaft (4), comprising an upper face (27) fixed on the lower face (28) of the second end of the second element (9) and a lower face (40) resting on the workpiece when said workpiece is fixed on the mounting axis (4) . Device according to one of claims 1 to 7, characterized in that the device comprises an indicator of the rupture of said load limiting element (6), able to emit an audible or visual alarm signal. Device according to claim 8, characterized in that said rupture indicator is a visual indicator consisting of a colored strip (29) surrounding the outer wall of the mounting pin (4), said strip being positioned on the mounting axis (4) so that it is made visible by the movement of said connecting element (2) a distance of δ from the so-called operating position to the so-called non-operating position. Device according to one of claims 1 to 9, characterized in that said first end of the second element (9) is provided with a mounting face (15) rotated on the end (16) facing said first element ( 8).

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