EP0330547A1 - Sling strap - Google Patents

Abstract

Sling strap, characterised in that the stirrup (4), which has a loop (5) comprising two side cheeks (9, 9') which each have holes (10, 10') in which pivots a revolving assembly (8) consisting of two positioning discs (11, 11') which are joined, on the one hand, by a receiving pin (12) forming an integral part of the receiving means and around which pin (12) the end (2) of the strap (1) is wrapped and folded back through 180 DEG , and, on the other hand, and on both sides of and parallel to the receiving pin (12), by two carrying pins (13, 13') which define between them a straight slot (14) which guides the end (2) of the strap (1) situated in line with the receiving pin (12). The assembly formed by the revolving positioning discs (11, 11') and the carrying pins (13, 13') form the positioning and guiding means of the strap (1). <IMAGE>

Description

The present invention relates to a sling-strap intended to allow the lifting and handling of objects or loads in particular by means of suitable machines such as overhead crane, hoist etc ...

The strap slings are conventionally constituted by metal loops around which the ends of the straps are fixed by means of seams. Such slings are far from being completely satisfactory, due to the relatively long delivery and manufacturing times linked to the compulsory use in the factory of a sewing machine and, above all, the fact that, once sewn, the length of the strap is irremovable, and offers no possibility of adjustment; it is therefore always necessary to have in stock a batch of sling straps of different lengths, which again increases their cost price under significant conditions.

In addition, the sewing operation causes a certain deterioration of the strap (thread cut by the stitching) which results in a reduction in the maximum load.

The object of the present invention is to remedy these drawbacks by proposing a strap sling consisting of a flat strap as well as at least one rigid loop stirrup fixed to at least one end of the strap, which can be Climb on place, without sewing operation, and, the length of which can be adjusted almost instantaneously, without any tools, while having a tensile strength at least equal to that of devices of the same conventional type used.

According to the invention, the rigid stirrup which advantageously consists of a hot forged piece of high-strength alloy steel, comprises means for receiving the end of the strap cooperating with means for positioning and guiding it. ci and with means for blocking the assembly thus put in place.

The sling-strap which is the subject of the invention is characterized in that the stirrup comprising two lateral cheeks respectively provided with bores in which is articulated a rotary assembly constituted by two positioning discs connected on the one hand by a receiving axis forming an integral part of the receiving means and around which the end of the strap is wound and brought back to 180 °, and, on the other hand, and on either side of the receiving axis parallel to this the latter, by two carrying axes defining between them a guide slot of the end of the strap located at the right of the receiving axis, the assembly formed by the rotary positioning discs and the carrying axes constituting the positioning means and strap guide.

It is, of course, necessary that shoulders are provided so that the positioning discs are perfectly maintained at the cheeks of the stirrup.

It is clear that the operation of preliminary positioning of the strap, during which the latter is somehow "preformed" without risk of damage, is extremely simple and does not require te no tools; it is only necessary to ensure that the length of the dead strand of the strap is sufficient.

Preferably, the receiving axis has a circular section, and the carrying axes are arranged symmetrically with respect thereto, and for example have a section in the form of a section of circle in order to define between them a rectilinear guide slot. ; this particular form should however in no way be considered as limiting and could be different without thereby departing from the scope of the invention; one can for example opt for load-bearing axes each consisting of two twinned circular axes.

To facilitate the triple axis rotation operation, one of the positioning discs or first positioning disc is preferably provided with a winding key.

According to another characteristic of the invention, the blocking means consist, on the one hand, of two ears integral with the rotary assembly and carrying respectively a perforation corresponding to a perforation of the stirrup, and, on the other hand , by a locking pin capable of being introduced into the perforations of the stirrup and of the rotary assembly to block the latter in rotation.

In the general case, the ears are fixed to the positioning disc, to the internal part of the stirrup, directly against the cheeks thereof, so as to have an element having optimum rigidity. To allow its installation and fixing, the locking pin is provided at one of its ends with a fin head and at its opposite end with a corresponding thread with a thread provided in one of the holes in the stirrup.

In addition to the aforementioned advantages, the mounting on the same rotation disk of the three axes forming a triple axis makes it possible to increase the rigidity of the assembly constituting the locking zone, to eliminate the phenomenon of bending of the axis and above all to accentuate to a large extent the moment of inertia.

According to this configuration, the forces are distributed predominantly on the triple axis, the balance of the forces passing through the fourth axis, that is to say the locking axis.

According to another characteristic of the invention, the reception means comprise a slit for the passage of the strap essentially parallel to the reception axis and receiving the two strands of this strap after winding around the reception axis.

For these reasons of ease of manufacture and as a result of lowering of the cost price of the device, the passage slot is most often defined by two axes of introduction arranged parallel to the axis of reception of the end of the caliper opposite the buckle and therefore the lifting zone.

According to another characteristic of the invention, the rotary assembly is movable between an insertion position in which the guide slot is located between the passage slot and the receiving axis, and a locking position offset by approximately 540 ° with respect to the insertion position in which the perforations of the ears and the stirrup are in correspondence to allow the positioning of the locking pin.

In accordance with the above configuration, to put the strap on the stirrup, we first introduce it by one of its ends into the passage slot before wrapping it around the receiving axis and then pass its end back into the passage slot; then the rotary triple axis is rotated so that the strap begins by covering one of the load-bearing axes and then the second; the rotation is maintained until the perforations of the ears and the stirrup are opposite, which corresponds to a total rotation of approximately 540 °; it then only remains to block the system in this position by screwing the locking pin.

This configuration has the advantage that the device is perfectly symmetrical and therefore that the direction of rotation of the triple axis is unimportant.

To have a satisfactory fixation, it is necessary to make sure that the dead end of the strap exceeds the stirrup by at least twenty centimeters.

According to the invention, the locking pin in fact has a double role: in fact, it ensures the blocking of the device and, at the same time, avoids the rejection of the strap in the upper part by ensuring its maintenance.

In addition, it is essential that, once in place, the strap can not slide laterally and therefore, that the width thereof corresponds exactly to that of the axes around which it is locked.

According to another characteristic of the invention, allowing an adaptation of the stirrup to straps of different thicknesses and different widths (therefore elements of its variable geometry), there is provided an adjustment element constituted by a tubular element essentially of same length as the locking pin which it is intended to receive as well as, if necessary, by two legs fixed to the tubular element approximately perpendicular ment to it and defining between them a spacing corresponding to the width of the strap to be put in place.

This tubular element has the advantage of avoiding rejection of the strap and therefore of acting as a template or gauge which keeps the strap in width in the system.

The diameter of the tubular element is a function of the thickness of the strap: in the particular case of very thin straps, a large tube is used to obtain a wedging effect such as to keep the strap permanently in its working axis. and a fortiori in cases of undervoltage or overvoltage.

In the case of straps of greater thickness, it is of course necessary to reduce in parallel the section of this tubular element.

In the case of narrow width straps, the tubular element cooperates with tabs whose role is to guide the strap vertically and horizontally and which are placed in the guide slot of the carrying axes.

In all cases, the adjusting element presses on the strap and on the triple axis, avoiding rejection.

It is clear that the strap is thus perfectly held laterally by the adjusting element.

The sling-strap which is the subject of the invention can give rise to several possibilities of use for lifting, guying, lashing or even be used in the context of tensioning systems (floating strap for anti barrier -pollution, for oceanographic space handling, for boating, etc.) which may give rise to naval, land or air applications. She can also Lely be transformed into a sliding sling by adding a hook with loop, or even be twinned so as to obtain a double traction system.

It is clear that the sling-strap which is the subject of the invention in addition to the above-mentioned advantages linked to its variable geometry (length / width) has a tensile strength equal to and even greater than that of devices of the same type. conventionally used: the strap does not by definition undergo any deterioration during assembly and disassembly of 100% of the fibers are used while in the classic configuration with seam, there is a loss of at least 20% of fibers (section per seam / stitching). This new strap sling therefore has an increased efficiency of at least 20%.

Of course, to obtain satisfactory resistance, the entire stirrup as well as the triple axis, the lugs and the locking pin must be made of a high-performance material, in particular of noble alloy steel.

Another advantage of the sling-strap which is the subject of the invention, directly linked to its perfect symmetry, is that it can have two active strands allowing the lifting of larger loads from two gripping points (two-strand sling).

In the case of a symmetrical load, to obtain a sling with two active strands, it suffices to wind and lock the strap in the usual position, then to pass the two strands above the axes of introduction and not in the passage slot as in the case of the single-strand sling to allow obtaining an angle α between the two strands and finally to connect to the lower ends from the latter a strap hook and adjust these two accessories on the two strands thus formed so that the tensile force is uniformly distributed over the two strands relative to the center of gravity of the load.

In the case of non-symmetrical loads, it is advantageous to adjust the length of the two strands before winding and the positioning of the locking blade; the device is then indeed mobile in sliding, which makes it possible to be easily placed in the axis of gravity.

This position having been established, it then only remains to wind and lock the strap and to carry out the final adjustment of its two lower ends.

• - la figure 1 représente une élingue-sangle conforme à l'art antérieur,
• - la figure 2 est une vue en perspective de l'élingue-­sangle conforme à l'invention,
• - la figure 3 représente l'étrier à boucle,
• - la figure 4 est une vue de profil de l'élingue-­sangle conforme à l'invention,
• - la figure 5 est une vue similaire à la figure 4, sur laquelle les différents axes sont représentés en pointillés,
• - la figure 5a est une coupe schématique montrant la position de l'ensemble rotatif lors de l'introduc­tion de la sangle,
• - la figure 5b est une vue correspondant à la figure 5a après rotation de 360° suivant la flèche I de l'ensemble rotatif,
• - les figures 6a à 6c représentent l'élément de régla­ge,
• - les figures 7 et 8 représentent une configuration particulière de l'élingue-sangle.

The characteristics of the sling-strap which is the subject of the invention will be described in more detail with reference to the accompanying drawings, in which:

• FIG. 1 represents a strap sling according to the prior art,
• FIG. 2 is a perspective view of the sling-strap according to the invention,
• FIG. 3 represents the loop stirrup,
• FIG. 4 is a side view of the sling-strap according to the invention,
• FIG. 5 is a view similar to FIG. 4, on which the different axes are shown in dotted lines,
• FIG. 5a is a diagrammatic section showing the position of the rotary assembly when the strap is introduced,
• FIG. 5b is a view corresponding to FIG. 5a after 360 ° rotation along arrow I of the rotary assembly,
• FIGS. 6a to 6c show the adjusting element,
• - Figures 7 and 8 show a particular configuration of the sling-strap.

According to Figure 1, the slings-straps of the prior art are constituted by a flat strap 1 which is fixed by sewing by one of its ends 2 around a ring 3 which can, for example, add a hook not shown.

Such devices of the prior art are commonly used in particular for lifting, guying, lashing and have a number of drawbacks mainly related, on the one hand, to the obligation of the implementation in the factory of 'a sewing machine to allow sewing operations, and, on the other hand, the impossibility of any adjustment of the length of the strap 1 (variable geometry).

According to Figures 2 and 4, the sling-strap according to the invention consists, on the contrary, of a rigid stirrup 4 provided with a loop 5 around which the end 2 of a strap 1 is wound and then locked in a particular way, which will be described in more detail above.

The configuration of the loop 5 which defines the lifting area of the sling-strap could of course be arbitrary without departing from the scope of the invention; by way of examples not shown in the figures, mention may be made of swivels with a large eye, with a small eye, with a clevis pin, with a fixed clevis, or else hooks with swivel or with safety (latch). These are of course elements of the technique conventionally and commonly used.

According to Figures 3 and 5, the stirrup 4 with loop 5 is provided, at its lower part with two axes parallel introduction 6, 6 ′ defining between two a passage slot 7 through which the end 2 of the strap 1 is introduced according to arrow A in the stirrup.

This insertion slot cooperates with an assembly 8 movable in rotation about an axis x-x ′ parallel to the introduction axes 6, 6 ′. To allow the establishment of this assembly 8, which will be described in more detail in the remainder of this description, the stirrup 4 is provided with lateral cheeks 9, 9 ′ respectively provided with circular holes 10, 10 ′.

According to Figures 3 and 5, the rotary assembly 8 consists of two positioning discs 11, 11 ′ connected on their periphery by a receiving axis 12 of circular section, as well as by two carrying axes 13, 13 ′ which have a section in the form of sections of a circle and define, between them, a rectilinear guide slot 14 which is located in line with the receiving axis 12. A winding key 15 makes it possible to manually rotate the assembly 8 around its axis of rotation xx ′.

According to FIG. 5a, to allow the introduction of the end 2 of the strap 1 into the stirrup, the rotary triple-axis assembly 8 is placed, by acting on the key 5, in a position in which the slot of guide 14 is located between the passage slot 7 and the receiving axis 12, then the end 2 of the strap 1 is wound around the axis 12 and brought back to 180 ° in the slots 14 and 7 so that it comes out again. It is, at this time, necessary to ensure that the length of the dead strand corresponding to the end 2 is sufficient to then have good support.

To achieve blocking of the strap 1, the rotation of the rotary assembly 8 with three axes 12, 13, 13 ′ according to arrow I is continued, the strap is then wound around the carrying axes 13 and 13 ′; after rotation of 360 ° around the axis xx ′ from the position shown in Figure 5a, the strap 1 is in the position shown in Figure 5b in which it is held more rigidly thanks to the double winding around the triple axis 12, 13, 13 ′; there is therefore "self-tightening" of the strap.

According to Figures 3 and 5, the positioning discs 11 and 11 ′ of the rotary assembly 87 carry respectively opposite the receiving axis 12, two ears 16, 16 ′ directly contiguous to the internal surface of the cheeks 9 , 9 ′ of stirrup 4.

These ears 16, 16 ′ carry perforations 17, 17 ′ intended to come during the rotation of the assembly 8 along the arrow I around the axis xx ′ in correspondence with perforations 18, 18 ′ provided in the cheeks 9, 9 ′ of stirrup 4.

According to Figures 3 and 5, the ears 16, 16 ′ are arranged in such a way that the matching of the perforations 17, 18, 17 ′, 18 ′ requires a rotation of the rotary assembly 8 by approximately 180 ° from from the position shown in Figure 5b. This angle of rotation - which has the advantage of giving the device perfect symmetry and therefore allowing the user to turn the triple axis 8 either in the direction I or in the opposite direction - could, of course, be different without for this is outside the scope of the invention.

According to FIG. 3, the presence of the perforations 17, 17 ′, 18, 18 ′ makes it possible to block the assembly 8 in rotation by virtue of a locking pin 19, one end of which carries an operating head 20 while the opposite end carries a thread 21 cooperating with a corresponding thread 22 provided in the part internal hole 18 of cheek 9 of stirrup 4.

According to Figure 4, the stirrup actually has two roles; it serves, of course, to allow lifting of loads from the mouth 4; moreover, the zones indicated has cheeks 9, 9 ′ situated on either side of the rotary assembly with triple axis 8 around which the strap 1 is wound ensure the protection of the latter vis-à-vis the abrasion (unlike the device of the prior art shown in FIG. 1 in accordance with which the strap is thickened around the ring 3, which leads to an abrasion phenomenon at the level of this ring when the sling-strap bears on floor).

According to Figures 6a, 6b and 6c, good support requires that the width 1 of the strap 1 corresponds approximately to the length of the three axes 12, 13, 13 ′ of the rotary element 8 (Figures 2 and 3) and that -this has a thickness such that it is perfectly maintained in the locking position between the locking axis 19 and the triple axis 12, 13, 13 ′; an adjustment element 23 allows the strap sling to adapt to all cases.

According to FIG. 6a, in the case of thin straps 1, it is necessary to provide around the locking pin 19 a tubular element 24 whose diameter is a function of the thickness of the strap 1 and whose length corresponds approximately that of three axes 12, 13, 13 ′, this element then alone constitutes the adjusting element 23.

According to FIG. 6b, if the width l ′ of the strap 1 becomes appreciably less than the length of the axes 12, 13, 13 ′, two guide tabs 25 and 25 ′ are added to the tubular element 24 fixed approximately perpendicular to this element and extending tangentially from the periphery of this itself, these legs delimiting between them a spacing 26 corresponding to the width l ' of the strap 1 and coming to be introduced into the guide slot 14 which separates the two carrying axes 13, 13 ′.

According to Figures 6b and 6c, it is of course necessary to choose an adjustment element 23 whose height h located between the spacing 26 defined by the legs 25 and 25 ′ and the tubular element 24 (depending on the diameter of the tubular element 24) increases when the thickness of the strap decreases; this zone h as well as the periphery of the tubular element 24 define a zone which can be used for marking and identification.

The addition of this part 23 allows almost universal use of the stirrup.

Furthermore, and still without departing from the scope of the invention, it could be proposed to substantially modify the configuration of the stirrup 4 and, for example as shown in FIGS. 7 and 8, to pair it in two stirrups 4 and 4₂ secured on one of their edges. It is thus possible to produce a double traction system therefore with double load.

The configuration shown in Figure 7 allows the use of a strap whose free end has no metal end, which is very popular in certain lifting operations where the loads to be handled are delicate; this configuration can in particular find applications in the spatial or oceanographic fields (hulls, cabins, ice, glass, polished sheet metal, etc.). No metal part is thus likely to strike and damage the load to be lifted, however hooking or lashing is instantaneous.

According to Figure 8, when applied to the guying, this twin configuration allows the passage of a double strap and therefore a double traction; in addition, a non-magnetic system is thus obtained since the strap is most often made of synthetic fibers.

In the particular case of guying, the locking pin can be held in a manner known per se by means of a bolt and a pin.

Claims (7)

1 °) Sling-strap intended to allow the lifting and the handling of objects or loads in particular by means of suitable machines such as crane, overhead crane, hoist etc ... and consisting of a flat strap (1) as well as at least one rigid stirrup (4) with loop fixed to at least one of the ends (2) of the strap (1), the rigid stirrup comprising means for receiving the end (2) of the strap (1) cooperating with means for positioning and guiding the latter and with means for blocking the assembly thus put in place, sling-strap characterized in that the stirrup (4) comprising two lateral cheeks (9, 9 ′) respectively provided with holes (10, 10 ′) in which is articulated a rotary assembly (8) constituted by two positioning discs connected on the one hand by a receiving axis (12) forming an integral part of the means receiving and around which the end (2) of the strap (1) is wound and brought back to 180 °, and, on the other hand, and on either side of the 'receiving axis (12) parallel to the latter, by two carrying axes (13, 13 ′) defining between them a guide slot (14) of the end (2) of the strap (1) located in line with the 'receiving axis (12), the assembly formed by the rotary positioning discs (11, 11 ′) and the carrying axes (13, 13 ′) constituting the means for positioning and guiding the strap (1). 2 °) sling strap according to claim 1, characterized in that the locking means consist, firstly, by two ears (16, 16 ′) integral with the rotary assembly (8) and respectively carrying a perforation (17, 17 ′) corresponding to a perforation (18, 18 ′) of the stirrup, and, on the other hand, by a locking pin (19) capable of being be introduced into the perforations (18, 18 ′, 17, 17 ′) of the stirrup (4) and of the rotary assembly (8) to block the latter in rotation. 3 °) sling-strap according to any one of claims 1 and 2, characterized in that the receiving means comprise a passage slot (7) of the strap (1) essentially parallel to the receiving axis (12) and receiving the two strands of this strap after winding around the receiving axis. 4 °) sling strap according to claim 4, characterized in that the passage slot (7) is defined by two axes of introduction (6, 6 ′) arranged parallel to the receiving axis (12) to the end of the stirrup (4) opposite the loop (5). 5 °) sling strap according to any one of claims 1 to 4, characterized in that the rotary assembly (8) is movable between an insertion position in which the guide slot (14) is located between the slot passage (7) and the receiving axis (12) and a locking position offset by about 540 ° relative to the insertion position in which the perforations (17, 17 ′, 18, 18 ′) of the ears (16, 16 ′) and the stirrup (4) are in correspondence to allow the establishment of the locking pin (19). 6 °) sling strap according to any one of claims 1 to 5, characterized in that one of the positioning discs (11 ′) or first positioning disc is provided with a winding key (15). 7 °) sling-strap according to any one of claims 1 to 6, characterized in that it comprises an adjusting element (23) constituted by a tubular element (24) essentially of the same length. so that the locking pin (19) which it is intended to receive, as well as, if necessary, by two tabs (25, 25 ′) fixed to the tubular element (24) approximately perpendicular thereto and defining between them a spacing (26) corresponding to the width of the strap (1) to be put in place.

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