EP0508889A1 - Closed sling with a self-tightening loop - Google Patents

Abstract

The sling is formed by a metal wire the two ends of which are permanently fixed to each other, particularly by splicing (1), and which forms a tightening loop (3) extended by a lifting loop (4) which is larger than the preceding one, sliding sleeves (10) connecting these loops in their neighbouring parts near the load taken by the tightening loop. According to the invention, the sling comprises at least two lifting loops (4, 5) which are formed with the same wire as at least one tightening loop (3). <IMAGE>

Description

The subject of the present invention is a closed sling with a self-tightening loop.

A sling of this type is known under the name "cinching". It is constituted by a metallic wire, steel noted, whose two ends are permanently fixed to each other; this wire forms an eight whose loops are folded over one another and connected together, on their common part, by sliding sleeves; the smallest loop is intended to surround the package and to self-tighten on it when the largest so-called lifting loop is suspended from a hook and that said package by weighing on it tends to lengthen it by narrowing the the smallest so-called tightening loop.

This sling has the disadvantage of consuming substantially twice as much metal wire as an ordinary endless sling normally arranged, that is to say without "dead tower" around the package. However, its advantages are manifold: it ensures that the elements making up the load are joined together and prevents the load from sliding, whether unitary or composite.

When we want to increase the lifting force, we multiply the number of slings suspended on the same hook and therefore implements as many tightening loops as lifting loops. The disadvantage of this arrangement is that the consumption of metal wire is excessive and costly.

The object of the present invention is to remedy this drawback by proposing a single sling which retains all the advantages of the aforementioned multiple slings, namely self-tightening of the package, the ease of fitting and removing the sling, the increase in lifting force.

For this purpose and in accordance with the invention, the same sling comprises at least two lifting loops formed in the same metal wire as at least one tightening loop.

According to a particularly advantageous embodiment, a ring constituted by the wire whose ends are permanently fixed to each other is formed into a double eight and folded back on itself in a Z at the location of the nodes so that the extreme loop and the largest intermediate loop or loops are superimposed between them and the another smaller extreme loop, the large loops for lifting and the small loop for self-tightening.

The means of fixing the ends of the metal wire is located at the top of the tightening loop in the middle.

Various other characteristics and advantages of the invention will also emerge from the detailed description which follows.

Embodiments of the subject of the invention are shown, by way of nonlimiting examples, in the accompanying drawings.

• la figure 1 est une vue en plan de l'anneau de base d'une élingue ;
• la figure 2 est une vue en plan montrant l'ébauche d'une première forme de réalisation de l'élingue ;
• la figure 3 est une perspective schématisant la mise en forme de l'élingue à partir de l'ébauche ;
• la figure 4 est une vue en plan illustrant, avec une légère déformation pour améliorer la compréhension, la fin de la mise en forme, c'est-à-dire avec les trois boucles superposées ;
• la figure 5 est une vue en plan représentant l'élingue obtenue après pose des manchons coulissants sur l'élingue selon la figure 4 ;
• la figure 6 est une vue analogue à la figure 2 montrant l'ébauche d'une deuxième forme de réalisation de l'élingue ;
• la figure 7 est une vue analogue à la figure 4 concernant cette deuxième forme de réalisation.

On this drawing :

• Figure 1 is a plan view of the base ring of a sling;
• Figure 2 is a plan view showing the blank of a first embodiment of the sling;
• Figure 3 is a perspective diagramming the shaping of the sling from the blank;
• Figure 4 is a plan view illustrating, with a slight deformation to improve understanding, the end of shaping, that is to say with the three superimposed loops;
• Figure 5 is a plan view showing the sling obtained after fitting the sliding sleeves on the sling according to Figure 4;
• Figure 6 is a view similar to Figure 2 showing the blank of a second embodiment of the sling;
• Figure 7 is a view similar to Figure 4 relating to this second embodiment.

Whatever the embodiment envisaged, the sling is constituted by a single metal wire, advantageously made of steel, the ends of which are solidly and definitively fixed together, in particular by means of a splice 1. The pre-blank thus obtained is then a closed ring 2.

According to the first embodiment shown in FIGS. 2 to 5, the sling comprises a tightening loop 3 and two lifting loops 4, 5 extending one, the other without a solution of continuity. The loop 3 is intended to be threaded onto the package to be moved and when the loops 4 and 5 are taken by a hook of a lifting machine they cause the tightening of the loop 3 on the package.

The lifting force depends on the original wire section and corresponds to the sum of the wire sections of loops 4 and 5. Of course, the single self-tightening loop 3 cannot break, since the development of the sling is continuous.

To make the sling from the ring 2, a flat blank 6 in double eight is formed therewith, that is to say a geometric figure with three loops shown diagrammatically in FIG. 2. An extreme loop and a middle loop of the same outline are intended to constitute the two aforementioned lifting loops 4 and 5, while the other extreme loop of smaller diameter than the previous ones is the self-tightening loop 3.

The following operation illustrated by FIG. 3, consists in folding the blank 6 in Z at the location of the crossing nodes 7 and 8 of the loops considered 3 to 5 and in folding down the loops 4 and 5 l according to the arrow F one on the other and along arrow G, these two loops on loop 3, so as to obtain the almost completed sling 9 shown, in a more or less exploded manner for greater clarity, in FIG. 4.

To ensure the holding of the sling while allowing the tightening of the tightening loop 3, sliding sleeves 10 connect the three loops 3 to 5 in their neighboring parts intended to be in contact with the package and the sling is then obtained closed 11 shown in Figure 5. It is important to note that the splice 1 or other fastening means: ligature, clip, collar, crimping sleeve, is located at the top of the tightening loop 3, substantially in the middle.

In general, a single tightening loop 3 is sufficient, but nothing prevents the provision of at least two, braced by means of protection of the package: bars, net ...

In the same way, the sling can comprise more than two lifting loops, which is illustrated by the second embodiment according to FIGS. 6 and 7.

In this second embodiment, the blank 12 shown in FIG. 6 has three lifting loops 4, 13, 5 and a tightening loop 3 formed in the pre-blank ring 2, loops which are connected together by crossing nodes 7, 14 and 8 offering no resistance to the sliding of the original wire.

As in the first embodiment, the loops of the blank 12 are folded against each other (Figure 7) and sliding sleeves 10 not shown are put in place.

Claims (3)

Closed sling with self-tightening loop, constituted by a metal wire whose two ends are definitively fixed to each other, in particular by splicing (1), and which forms a tightening loop (3) extending by a loop of lifting (4) greater than the previous one, sliding sleeves (10) connecting these loops together in their neighboring parts, close to the load taken up by the tightening loop,
characterized in that it comprises at least two lifting loops (4, 5; 4, 5, 13) formed in the same wire as at least one tightening loop (3). Sling according to claim 1, characterized in that a ring (2) constituted by the wire, the ends of which are definitively fixed to each other, is formed in double eight and folded back on itself in Z at the place nodes (7, 8; 7, 8, 14) so that the larger end loop (4) and the one or more intermediate loops (5; 5, 13) are superimposed on each other and on the other smaller end loop (3), the large loops ensuring the lifting and the small one, the self-tightening. Sling according to claim 1 or 2, characterized in that the fixing means (1) of the ends of the wire is located at the top of the tightening loop (3) in the middle.

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