EP0058810A1 - Openable pulley block - Google Patents

Abstract

1. Openable pulley or muffle of the type comprising two support flanges (3, 4) or two support brackets (10, 14) with two flanges (3, 4) one of which (3) supports both the sprindle (6) of at least one groove pulley (1) over which there passes a cable (2) and, directly or by means of another component, a pivot axis (9), supporting an openable portion (4) such that the pivoting of this portion (4) about the said axis (9) enables the introduction of the cable (2) or its release from between the two flanges (3, 4), whereas a means for suspending the pulley or the load, such as a hook (5), whose axis passes substantially through the median plane of the groove pulley (1), is connected to one of the flanges (4) indirectly via a component such as a stud crossbar (15), this crossbar (15) being located, with respect to the axis (6) of the groove pulley (1), on the same side as the axis of opening (9) of the pulley or muffle, the hook (5) being connected to the openable portion (4) and not to the flange (3) supporting the groove pulley (1) such that the traction effort exerted by the load on the groove pulley (1) via the cable (2) creates torques whose effect is to close the openable portion (4) of the pulley/muffle if it is open, characterised in that the openable portion connected to the hook (5), and constituted by the flange (4) which does not support the groove pulley (1), has its pivoting axis (9) orientated perpendicularly to the axis (6) of the groove pulley (1) and offset with respect of the median plane of the groove pulley (1) such that the traction effort exerted by a load not only causes the closure of the pulley/muffle by closing up its two flanges (3, 4) but also maintains this pulley in the closed position during the entire period in which the effort due to the load is applied, means (21, 31, 43, 54, 54a) being provided so as to keep the two flanges (3, 4) spaced from one another if no effort due to a load is being applied, without opposing the closure of the pulley/muffle under the action of a load.

Description

The present invention relates to a pulley or an opening block, of the type comprising two load-bearing flanges, or two load-bearing fittings supplemented by two flanges, one of which simultaneously supports the axis of at least one sheave over which a cable and, directly or through another part, a pivot axis perpendicular to the axis of the sheave and offset, relative to the median plane of the sheave, on the side of the flange not carrying the sheave, this axis pivoting bearing itself, directly or through another part, the flange not carrying the sheave, so that the pivoting of the latter flange around said axis allows the introduction of the cable or its release d '' between the two flanges, while a means for suspending the pulley or the load, such as a hook, the axis of which passes substantially through the median plane of the sheave, is connected to one of the flanges, either directly by a transverse block forming a body with this flange, or indirectly p ar by the intermediary of a part such as a cross with pins or trunnions, this block or this cross being located, relative to the axis of the sheave, on the same side as the opening axis of the pulley or block. Such a device, usable as a deflection pulley suspended by its hook, but also as a fixed or movable block in hauling, lifting, horizontal traction or oblique traction, 'can be opened or closed whether it is hung by its hook , or hung on the cable, or that it rests on the ground in any position.

We already know opening pulleys of this kind, also called "cut" pulleys, in which the two flanges are articulated to each other by an axis located between the sheave and the hook, with a position offset laterally. In these known devices, the hook is secured to the flange which carries the sheave. Locking means in the closed position are also already known for these opening pulleys, but on the one hand they do not provide absolute security: in the event of forgetting to close and lock, or in the event of failure of these locking means, the flanges tend to move apart under the effect of the load, hence the risk of opening, of cable exit, load drop, e _' tc ..., and secondly the so-called "safety" systems do not allow opening in all positions of the device, especially if the device hangs by its hook.

The present invention seeks to remedy these drawbacks by providing a deflection pulley or an improved opening block in which, on the contrary, the mere presence of a load automatically causes closing and locking, and in which opening, generally after prior manual unlocking, can only occur after removal of the traction force applied via the cable, in order to avoid any accident. Another object of the invention, in conjunction with the above, is to provide an apparatus which can be easily opened by one man if the apparatus remains suspended, after removal of the traction due to the load, and which is maintained then open on its own, the man can thus always use his two hands to introduce or remove the cable, before closing the device, or even letting it close itself under the effect of the load; the man must also be able to carry the open device with both hands to place it on the cable.

To this end, the invention essentially relates to an opening pulley or block of the kind mentioned in the introduction, but in which, unlike known embodiments, the hook is connected to the flange not carrying the sheave, therefore pivots with this flange by compared to the flange which carries the sheave, so that the tensile force that a load exerts via the cable on the sheave creates couples whose effect is to bring the two flanges one of imperatively the other, thus closing the pulley / block if it was open and kept closed for the duration of the application of the force due to the load, so that this pulley / block cannot remain open when it is lifting a load.

The arrangement chosen implies that the axis of the hook forms a certain angle with the median plane of the sheave, when the flanges are spaced apart, that is to say the open pulley; the presence of a load results in a traction which tends to cancel this angle, that is to say to confuse the axis of the hook and the median plane of the sheave, therefore to keep the pulley in its closed position. Thus, only the removal of the load makes opening possible and the return of the flanges in the closed position takes place automatically, as soon as a load is attached, which is an additional advantage compared to known devices which require delivery in place manually tilting or rotating flanges, or hinges and hook-carrier crosspieces in other opening pulley systems.

• Une première solution consiste à prévoir des moyens à butée, limitant l'angle de pivotement de l'ensemble "flasque ne portant pas le réa + crochet" par rapport à l'ensemble "flasque non lié au crochet + réa", dans le sens de la fermeture de la poulie/moufle sous l'effet d'une charge, de telle sorte que l'appui d'un ensemble sur l'autre n'engendre pas d'efforts de flexion que les pièces ne pourraient supporter, ces moyens à butée ayant aussi pour effet de supprimer, dans la position fermée de la poulie/moufle, la transmission de l'effort dû à la charge par l'intermédiaire de l'axe de pivotement. Il en résulte que cet axe, n'étant plus porteur de la charge mais seulement accessoire pour permettre l'ouverture de la poulie, peut être sensiblement réduit en diamètre.

Torques of forces, which tend to bring the flanges together and keep the pulley in the closed position, also have the effect, when one flange rests on the other via the axis of the sheave or in any other way , to tend to flex the flanges and other parts subjected to these couples. These bending effects are variable, depending on the distances between the flanges, the hook axis and the pivot axis of the movable flange, and the invention also provides means making it possible to limit or avoid such bending, if this is necessary:

• A first solution consists in providing stop means, limiting the pivoting angle of the "flange not carrying the sheave + hook" assembly relative to the "flange not linked to the hook + sheave" assembly, in the direction closing of the pulley / block under the effect of a load, so that the support of one assembly on the other does not generate bending forces that the parts could not withstand, these stop means also having the effect of eliminating, in the closed position of the pulley / block, the transmission of the force due to the load via the pivot axis. As a result, this axis, no longer carrying the load but only accessory to allow the opening of the pulley, can be significantly reduced in diameter.

If it is an opening pulley in which a transverse block linked to the hook forms one with one of the flanges, the support in the closed position can be produced between, on the one hand, a face of said transverse block which is secured to the flange not carrying the sheave, and on the other hand, at least one lug secured to the flange that carries the sheave.

If it is an opening pulley in which one of the flanges is linked to a hook-carrying cross-member, the abovementioned abutment means may result from the fact that said cross-member, linked to the flange not carrying the sheave, has a stud engaged in a lumen of the flange which carries the sheave, so that in the closed position of the pulley / block, the support is produced between this stud and the edge of the light, the pivot axis passing through or well through the cross itself, or through the flange not carrying the sheave and linked to said cross.

To completely avoid the bending forces in the closed position, said abutment means require a precise adjustment, which can however be avoided by making, with a certain flexibility in a transverse plane, the connection between the stud cross member, therefore the hook. , and the flange not carrying the sheave, for example by making this connection by means of a nut placed at the end of one of the nipples and pressing at least one elastic washer against the flange not carrying the sheave, or against the bearing hardware of this flange. Alternatively, it is the connection between the pivot axis and the flange carrying the sheave which is produced with a certain flexibility, by means of a yoke, the mounting of which on said flange for example uses at least one elastic washer interposed between these two elements and held by the tightening of a nut. By providing such flexible connections, in particular by the use of elastic washers, it is obtained that the forces of the couples liable to cause the bending of the flanges / fittings will press the elastic washers and allow a certain modification of the angle, substantially straight, formed either by the flange not carrying the sheave with the cross member, or by the flange carrying the sheave with the yoke carrying the hinge pin for opening the pulley. It is this slight modification of the angle considered which makes it possible to avoid bending of the flanges / fittings.

According to another characteristic of the invention, in order to facilitate the operations of entering and leaving the cable using two hands, spring means are provided to keep the two flanges apart from one another. , or to bring the two flanges in the separated position and keep them there, until the tensile force exerted by the weight of the cable and / or the load, or the weight of the device resting on the cable and / or of the load, becomes greater than the resistance of said spring means.

• - d'un ressort fixé sur la flasque liée au crochet et comportant une partie incurvée coopérant avec l'extrémité libre de l'axe du réa, porté par l'autre flasque, extrémité sur laquelle sont ménagées une rampe et une gorge aptes à recevoir la partie incurvée dudit ressort ;
• - ou d'un cliquet monté pivotant sur la flasque liée au crochet, ce cliquet étant soumis à l'action d'un ressort et coopérant avec l'extrémité libre de l'axe du réa, porté par l'autre flasque, extrémité sur laquelle sont ménagées une rampe et une gorge aptes à recevoir ledit cliquet.

Preferably, other spring means are also provided to ensure automatic locking when closing the pulley / block under the effect of a load, these means requiring manual unlocking to allow the opening of the pulley / muffle. These locking means prevent the opening of the pulley from occurring as soon as the load is removed, if the first spring means are designed to bring the flaccid ones into the separated position and keep them there, or accidentally under the effect of '' involuntary external action. The opening of the pulley by spacing the two flanges can only be done after unlocking manual age, by the operator. On the other hand, said locking means are designed to be put in place automatically, when the pulley is closed under the effect of a load. They can be constituted, in particular, in the form:

• - A spring fixed on the flange linked to the hook and comprising a curved part cooperating with the free end of the axis of the sheave, carried by the other flange, end on which are formed a ramp and a groove capable of receiving the curved part of said spring;
• - Or a pawl mounted to pivot on the flange linked to the hook, this pawl being subjected to the action of a spring and cooperating with the free end of the sheave axis, carried by the other flange, end on which are provided a ramp and a groove adapted to receive said pawl.

• Si les moyens de verrouillage automatique et de déverrouillage manuel sont détériorés, l'appareil peut s'ouvrir par exemple lorsqu'il a posé une charge sur le sol et, éventuellement, le câble risque de sortir de la gorge du réa et de tomber au moment où l'opérateur s'apprête à remonter la charge. Ainsi le choix d'une ouverture automatique ne présente pas une sécurité totale, notamment en cas de traction oblique lorsque la tension du câble devient très faible, et si les moyens de verrouillage ne sont pas d'une fiabilité absolue et sont susceptibles de devenir défectueux.

As for the first spring means, according to one embodiment of the invention, they consist of an opening spring, in particular wound around the axis by which the two flanges are articulated and bearing on these two flanges, so to tend to spread them and keep them in the spread position, until voluntary manual or automatic closing under the effect of a load. This spring therefore ensures automatic opening of the pulley, after removal of the load and after manual unlocking, in the case where locking means in the closed position are provided. This version of the device which is the subject of the invention therefore comprises, both, an automatic closing and locking under the effect of the load, and an automatic opening under the action of a spring, after cancellation of the load. and manual unlocking; a disadvantage is however the following:

• If the automatic locking and manual unlocking means are damaged, the device can open for example when it has placed a load on the ground and, possibly, the cable may come out of the throat of the sheave and fall as the operator prepares to raise the load. Thus the choice of an automatic opening does not present total security, in particular in the case of oblique traction when the cable tension becomes very low, and if the locking means are not of absolute reliability and are liable to become defective. .

This drawback is eliminated in another embodiment of the invention, no longer comprising a spring to ensure both automatic opening and keeping in the open position, but in which a spring is provided, carried by one of the flanges, such as that carrying the sheave, or by an element integral with this flange, and able to snap onto an element integral with the other flange, such as that linked directly or indirectly to the hook, when the two flanges are separated one from the other, to maintain the two flanges in this separated position, until voluntary manual or automatic closing under the effect of a load. In this other version, which may or may not include means for automatically locking the closure with manual unlocking, the automatic closing of the pulley is guaranteed by the traction force, according to the basic idea of the invention, even if operator failed to close device; it is made perfectly safe, and the invention thus provides a pulley _'opens high security, as it does not currently exist. In this case, the effort to be exerted will be greater to open the pulley until the spring engages, especially if a cable of a certain weight is engaged in the groove of the sheave, but the effort to be provided remains reasonable, while at least for devices with common capacities.

• - selon une première possibilité, il s'agit d'un ressort profilé, porté par l'une des flasques, telle que celle portant le réa, et permettant l'enclenchement d'un téton solidaire de l'autre flasque, telle que celle liée au crochet, lorsque les deux flasques sont écartées l'une de l'autre.
• - selon une deuxième possibilité, il s'agit d'un ressort en forme d'étrier, dont les extrémités sont liées à deux oreilles elles-mêmes liées à la flasque portant le réa et formant une chape sur laquelle est montée pivotante l'autre flasque liée au crochet, la partie médiane dudit ressort en forme d'étrier étant engageable dans une gorge annulaire de l'écrou de retenue du crochet, lorsque les deux flasques sont écartées l'une de l'autre.

Various forms can be given to the spring whose function is to maintain the flanges in the separated position:

• - according to a first possibility, it is a profiled spring, carried by one of the flanges, such as that carrying the sheave, and allowing the engagement of a stud secured to the other flange, such as that linked to the hook, when the two flanges are spaced apart the other.
• - According to a second possibility, it is a caliper-shaped spring, the ends of which are linked to two ears themselves linked to the flange carrying the sheave and forming a yoke on which the other is pivotally mounted. flange linked to the hook, the middle part of said stirrup-shaped spring being able to be engaged in an annular groove of the hook retaining nut, when the two flanges are spaced from one another.

Advantageously, in the case of a pulley with a hook-carrying cross member, and when the pivot axis passes through the cross member, the stud of the latter, engaged in a slot in the flange and / or the fitting carrying the sheave, constitutes also the stud which, in the open position, engages in the profiled spring, if this kind of spring is envisaged to keep the flanges apart from one another. In the case where the pivot axis crosses the upper part of the flange or. fitting, the aforementioned stirrup spring, supported by the hook retaining nut, may be preferable.

In all the embodiments defined above, the spring means which keep the two flanges apart from one another, in the open position of the pulley / block, and the spring means which ensure the automatic locking when closing the pulley / block under the effect of a load, are designed as two entirely separate devices, which must be added one and the other on the basic elements that the pulley / block opening. This results in a certain complexity of production, resulting in particular in a multiplication of parts such as pins and springs, or machining such as those necessary for the realization of the various grooves previously mentioned. The present invention also provides other embodiments, comprising a constructive simplification and in particular limiting the number of complicated and fatigue-prone production parts, by virtue of a single and simple device capable of performing the functions of automatic locking of the pulley / block in the closed position, manual opening of the lock and, by continuity of movement, opening of the flange and then maintaining it in the open position, without opposing the automatic closing of said pulley / block from the open position by a progressive movement, the whole always ensuring safety in use when a load is applied according to the fundamental characteristic of the invention.

To this end, the means provided, on the one hand, for keeping the two flanges apart from one another and, on the other hand, for ensuring automatic locking during closing are constituted by a single pawl mounted pivotally on the flange or its supporting fitting linked to the hook and not carrying the sheave, said pawl, subjected to the action of a spring tending to rotate it in a determined direction, capable of cooperating on the one hand, in the closed position of the pulley / block, with a complementary housing of an element integral with the flange carrying the sheave, and on the other hand, in the open position of the pulley / block, with a bearing surface belonging to this element integral with the flange carrying the sheave, said bearing surface and / or the part of the pawl which cooperates with this surface forming a ramp or a cam which allows, during the application of a load, the sliding of one on the other against the action of the aforementioned jurisdiction, in the sense of bringing together ix flanges of the pulley / block.

Thus the same pawl pivotally mounted on one of the flanges, and possibly the same part of this pawl, ensures on the one hand the locking when the pulley / block is closed, by cooperating with an element secured to the other flange and then placed in a first position relative to the pawl, and on the other hand the retainer in the open position (without locking but by obtaining a certain sufficiently stable balance ), always cooperating with the same element, then placed in a second relative position. The spring also remains unique in this device.

According to one embodiment, the pawl is pivotally mounted on the flange or its bearing fitting linked to the hook and does not carry the sheave along an axis parallel to the pivot axis of said flange, and this pawl, which the aforementioned spring tends to be brought closer to said flange, comprises on the one hand a lever making it possible to move it away from said flange against the action of the spring, and on the other hand a finger capable of cooperating either with a housing or with a boss with curved profile, both belonging to an element secured to the flange carrying the sheave. This element is advantageously constituted by one of the arms of a yoke integral with the flange carrying the sheave and supporting the hinge pin of the other flange, in which case no additional part is necessary: it suffices to give at one of the edges of this clevis arm a special profile, with a recess which constitutes the housing of the pawl finger in the locked closed position, and with a boss on which the same pawl finger rests, in the open position of the pulley / block.

According to another embodiment, the pawl is pivotally mounted on the flange or its supporting fitting linked to the hook and does not carry the sheave along an axis perpendicular to the plane of said flange, and this pawl comprises on the one hand an operating lever , and on the other hand a head of at least partially conical shape, while the complementary element integral with the flange carrying the sheave has a folded part parallel to the latter flange, so that the head of the pawl can either engage between said folded part and the flange or its supporting fitting linked to the hook, the aforementioned spring tending to hold the pawl in this position, or be supported externally against said part folded by its conical surface. This folded part is advantageously constituted by an extension bent at right angles to one of the arms of a yoke integral with the flange carrying the sheave and supporting the axis of articulation of the other flange. In the closed position = e the pulley / block, the head of the pawl, interposed between the opening flange and the bent extension or clevis arm, and held by the spring in this arrangement, prevents any separation of the two flanges. In the open position of the pulley / block, the support of the ratchet head against the bent extension of the yoke arm maintains this position, while the conical shape of said head allows its sliding on its support surface when closing the pulley / block.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing which illustrates the principle thereof and which represents, by way of nonlimiting examples, some embodiments of this pulley opening:

• Figure 1 is a very schematic side view, with partial section, recalling the principle of a known opening pulley, with indication of the open position;
• Figure 2 is a very schematic front view, corresponding to the known pulley of Figure 1 but also to the pulleys according to the invention of the following figures;
• Figure 3 is a very schematic side view, showing another known opening pulley;
• Figure 4 is a very schematic side view, with partial section, illustrating the principle of the opening pulley according to the invention;
• Figure 5 is a block diagram similar to Figure 4, showing a first embodiment of the means to stop limiting the pivoting angle of the assembly "flange not carrying the sheave + hook", with indication of the open position;
• Figure 6 is a block diagram similar to the previous, showing a second embodiment of said stop means;
• Figure 7 is a side view of an embodiment of the opening pulley according to the invention shown in detail, with a pawl mounted pivotally along an axis parallel to the axis of articulation of the two flanges, in the closed position and locked by this ratchet;
• Figure 8 is a view similar to Figure 7, but showing the open position, in which the same pawl keeps the two flanges apart from one another;
• Figure 9 is a front view, in the closed position, of the opening pulley of Figures 7 and 8;
• Figure 10 is a side view of another embodiment, with a pawl mounted pivoting along an axis perpendicular to the plane of the flange connected to the hook, in the closed position and locked by this pawl, and also with partial indication of the open position in which the same pawl keeps the two flanges apart from one another;
• Figure 11 is a front view of the opening pulley of Figure 10;
• Figure 12 is a partial sectional view along 12-12 of Figure 11;
• Figure 13 shows, in perspective, the pawl alone of the embodiment according to Figures 10 to 12;
• Figure 14 is a detailed front view of an opening pulley according to the invention, provided with a spring capable of holding the two flanges apart from one another;
• Figure 15 is a side view of the pulley according to Figure 14, shown in the open position;
• Figure 16 is a detailed front view of an opening pulley according to the invention, provided with a suitable spring bringing the two flanges into the separated position and keeping them there;
• Figure 17 is a vertical sectional view along line 17-17 of Figure 16;
• Figure 18 is a side view of the pulley according to Figures 16 and 17 shown in the open position;
• Figures 19, 20 and 21 are very schematic side views, with partial sections, illustrating the principle of the opening pulleys according to the invention including a flexible connection to avoid bending forces in the closed position;
• Figure 22 is a detailed front view of an opening pulley provided with such a flexible connection, between the hook-carrying cross member and the flange not carrying the sheave;
• Figure 23 is a vertical sectional view along line 23-23 of Figure 22;
• Figure 24 is a horizontal sectional view, on an enlarged scale, along 24-24 of Figure 22;
• Figure 25 is a vertical sectional view similar to Figure 23, but in the open position;
• Figure 26 is a detailed front view of an opening pulley, constituting a variant of the preceding figures;
• Figure 27 is a plan view from above of the pulley of Figure 26, without its hook and without its lower part;
• Figure 28 is a vertical sectional view along 28-28 of Figure 26;
• Figure 29 is a partial view, along arrow F of Figure 28;
• Figure 30 is a vertical sectional view similar to Figure 28, but in the open position.

The known opening pulley, the principle of which is recalled by FIGS. 1 and 2, generally comprises: a sheave 1 in the groove of which passes a cable 2, two carrying flanges 3 and 4, and a hook 5. The sheave 1 is mounted to rotate on an axis 6 fixed, by means of a nut 7, to the flange 3, the upper part of which is integral with the hook 5. This upper part of the flange 3 is further extended by two ears 8 which form a sort of clevis supporting an axis 9, in a direction perpendicular to the axis 7 of the sheave 1. The second flange 4 is pivotally mounted, by its upper part, around the axis 9, to allow the opening of the pulley (position indicated in dashed lines in Figure 1). As shown in Figure 2, the flange 4 can be mounted on a support fitting 10, in which case it is the upper part of the fitting 10 which is crossed by the axis 9. In the closed position, the two flanges 3 and 4 being parallel, and the axis 6 passing through an opening of the flange 4, the pulley is locked by a spring 11, carried by the fitting 10 and / or the flange 4, and engaged in a groove 12 produced near the free end of the axis 6, which has a frustoconical conformation 13 constituting a ramp for the engagement of the spring 11.

FIG. 3 shows another known opening pulley, in which the bearing fitting 14 of the flange 3 carrying the sheave 1 has its upper part linked to the hook 5 indirectly, that is to say by means of a cross member 15, one end of which, shaped as a stud or a journal, is linked to the flange 3. The other end of the cross member 15 is linked to an intermediate piece 16, supporting the pin 9 on which the carrier fitting 10 is pivotally mounted flange 4.

Whatever their execution details, the known opening pulleys, previously described; have their hook 5 secured, directly or indirectly, with the flange 3 which carries the sheave 1. As a result, in the unlocked position, or in the event of failure of the locking means 11-12, the flanges 3 and 4 can spread.

On the contrary, in the opening pulley object of the in vention, the principle of which is illustrated in FIG. 4 (where the corresponding parts retain the same references as previously), the hook 5 is connected to the flange 4 which does not carry the sheave 1, therefore pivots around the axis 9 with this flange 4 (see also the line in phantom in Figure 5). It follows that the tensile force f, which a load exerts via the cable 2, tends to bring the flanges 3 and 4 together, therefore tends to close the pulley or to maintain it closed.

The hook 5 can be fixed, as shown in FIGS. 4 and 5, to a transverse block 17 which laterally extends the upper part of the flange 4 (or of its possible supporting fitting 10). The axis 9 can in this case cross said block 17, as well as the two ears 8 integral with the flange 3. In the completely closed position, one or two lugs 18, which comprise the ears 8 or the flange 3, serve as a stop for the transverse block 17 (see Figure 5), therefore limit the pivot angle of the assembly "flange 4 + hook 5".

Figure 6 shows, in principle, another embodiment of the opening pulley object of the invention, with a cross member 15 carrying the hook 5, according to the design already mentioned with reference to Figure 3. The flange 4 not carrying the shea 1 is linked to one end of the cross-member 15, so that this flange 4 will pivot with the hook 5 around the axis 9, which, as shown, can cross the cross-member 15. To produce means with a stop equivalent to the lugs 18 of Figure 5, the cross member 15 here comprises, at its end remote from the flange 4, a lug 19 engaged in a slot 20 of the flange 3 which carries the sheave 1. In the closed position, the lug 19 comes to bear against the upper edge of light 20.

Figures 7,8 and 9 show, in detail, a first embodiment of an opening pulley is closing and now being closed under the effect of the load, according to the principle explained above, the two fuzzies 3 and 4 being here mounted respectively on load-bearing fittings 14 and 10. The fitting 14 secured to the flange 3 supports, at its top , a yoke formed by two parallel arms 8, which are for example welded to said fitting and which support an axis 9, on which is hinged the fitting 10 secured to the other flange 4. The hook 5 is here attached to a cross member 15 which laterally extends the upper part of the fitting 10, and which comprises a lug 19 cooperating with a slot 20 in the fitting 14.

According to the particularity of the embodiment of FIGS. 7 to 9, the fitting 10 of the flange 4 linked to the hook 5 has a lateral recess 52, at the level of which is pivotally mounted, around an axis 53 parallel to the axis pivoting 9 of the flange 4, a pawl designated as a whole by the reference 54. Around the axis 53 is also wound a spiral spring 55, the ends of which rest on one of the flange 4, the other on the pawl 54, so that this spring 55 tends to bring the pawl 54 closer to the flange 4.

The pawl 54 includes an operating lever 56, extending approximately along a vertical edge of the fitting 10 and making it possible to separate said pawl 54 from the flange 4, against the action of the spring 55. For that the lever 56 can be grasped easily, it has a curved free end, located at the level of a recess 57 of the fitting 10. The pawl 54 also comprises a branch which forms substantially a right angle with the lever 56 and which comprises a locking finger 58 turned upwards.

The finger 58 is located opposite the lower edge of one of the yoke arms 8, the edge which comprises on the one hand a recess 59 complementary to the dcigt 58, on the other hand a boss 60 with a curved profile.

In the closed position of the pulley (see figure 7), the pawl 54 has its lever 56 parallel to the flange 4 and to the fitting 10, while its finger 58 is inserted into the recess 59 of the clevis arm 8. This engagement of the finger 58 in the housing that constitutes the recess 59 is held by the spring 55, and a real locking in the closed position is therefore achieved.

To open the pulley, and therefore to move aside the flange 4 from the flange 3, the lever 56 of the pawl 54 must first be pulled to the position indicated in dashed lines in FIG. 7, position which allows the finger 58 to come out completely housing 59 and coming into contact with the boss 60. The pulling movement of the lever 56, being continued in the same direction, allows by continuity to open the pulley, by pivoting the flange 4 around the axis 9 .

Once this flange 4 is moved away from the flange 3, the lever 56 of the pawl 54 is released. As shown in FIG. 8, the finger 58 of the pawl 54 then comes into contact with the edge of the boss 60 in its part remote from the recess 59. The system then remains in equilibrium, by the action of the spring 55; the pulley is thus kept in the open position.

In the event of application of a force tending to close the pulley, and acting either on the flange 4 (manual closing force), or on the sheave 1 (automatic closing force by the weight of a load), the action of the spring 55 is overcome. The finger 58 of the pawl 54 slides along the edge of the boss 60 of the clevis arm 8 and finally "drops" back into the housing 59, which causes the automatic resetting of the locking device when the closed position is reached.

In the embodiment according to FIGS. 10 to 13, the pawl 54a is pivotally mounted, on the assembly constituted by the flange 4 and its supporting fitting 10, around an axis 53a which is perpendicular to the plane of the flange 4 , and offset laterally with respect to the axis of symmetry of this flange 4. A spring 55a, shown partially felt, is wound in a spiral around the axis 53a, while its ends are supported one on an edge of the fitting 10 and the other on the pawl 54a.

This pawl 54a comprises an operating lever 56a, turned downwards, and its upper part forms a head 58a having a conical surface, the conformation of said pawl 54a being clearly visible in FIG. 13.

One of the yoke arms 8 has an extension 60a bent at a right angle and thus coming in front of the fitting 10. In the closed position of the pulley, the extension 60a is parallel to the fitting 10 and to the flange 4, and the distance which separates said extension 60a from the fitting 10 corresponds substantially to the thickness of the head 58a of the pawl 54a.

Thus, in the closed position of the pulley, the head 58a of the pawl 54a is introduced into the housing 59a of corresponding dimension delimited: by a part of the clevis arm 8 considered, by the extension 60a of this arm, and by the external face of the fitting 10. The spring 55a acts on the pawl 54a in the direction of engagement and maintenance of the head 58a in the housing 59a, and the presence of the head 58a in the housing 59a prevents any separation of the two flanges 3 and 4, so that the locking in the closed position is achieved.

To open the pulley, therefore to move aside the flange 4 from the flange 3, the lever 56a of the pawl 54a is pushed to the position indicated in dashed lines in FIG. 10; this movement releases the head 58a from the pawl 54a, bringing it below the bent extension 60a therefore out of the housing 59a. The locking being thus removed, the pulley can be opened, by pivoting the flange 4 around the axis 9.

Once the pulley is open, the lever 56a of the pawl 54a is released. As shown in the dashed line in FIG. 10, the head 58a of the pawl 54a then comes into contact with the lower edge of the extension bent 60a of the yoke arm 8, and the system remains in equilibrium by the combined action of the spring 55a and the taper of the head 58a of the pawl 54a.

In the event of application of a force tending to close the pulley, the action of the spring 55a is overcome. The conical surface of the head 58a of the pawl 54a slides on the lower edge of the bent extension 60a of the clevis arm 8, finally causing the automatic resetting of the locking.

Figures 14 and 15 show, in detail, another embodiment of an opening pulley according to the invention, in which it is a spring 21, in the form of a profiled blade, which keeps the pulley open when the two flanges 3 and 4 have been separated, at the same time as the corresponding fittings 14 and 10. The two ends of the spring 21 are fixed by means of members 22 such as screws or rivets between the two ears 8 forming the yoke located at the top of the fitting 14 which carries the flange 3 and the sheave 1. The other fitting 10, carrying the hook 5, has its upper transverse block 17 provided with a stud 23 intended to be engaged in the spring 21.

A certain manual effort must be exerted to open the pulley, by pivoting the fitting 10 around the axis 9, and to engage the stud 23 in the spring 21. This effort is weakest when the apparatus rests on the ground. , because the operator does not have to overcome the weight of the device and the cable 2.

Locking in the closed position of the pulley according to FIGS. 14 and 15 is ensured by another spring 11, made of steel wire, fixed by a rivet 24 on the fitting 10 and on the flange 4. This spring 11 comprises a curved part , able to automatically engage in the groove 12 of the axis 6, after "mounted" on the frustoconical end 13 of this axis 6. Two stops 25 and 26 position the spring 11 so that it occurs correctly at the end of axis 6, when closing the pulley.

In addition to the opening 27 of the flange 4 and the fitting 1Q which allows the passage of the axis 6 in the closed position, the same parts are here pierced, in their lower part, with an additional opening 28 receiving in position closed the free end of an axle 29 which carries a becket 30 and which is fixed to the lower part of the flange 3 and of the fitting 14.

FIGS. 16 to 18 relate to another embodiment, where the two flanges 3 and 4 are devoid of bearing fittings, but which is distinguished above all by the fact that a spring 31 is mounted so as not only to keep the pulley open, but also to bring the two flanges 3 and 4 in the separated position, after unlocking.

The spring 31 is wound around the axis 9 by which the two flanges 3 and 4 are articulated, and it bears against the internal faces of the latter, acting in the direction of their spacing, therefore in the direction of the opening of the pulley.

• a) Le ressort 31 peut être choisi suffisamment fort pour que la flasque 4 s'écarte d'elle-même, après déverrouillage manuel, lorsque la charge ne correspond qu'au poids du câble 2 qu'un homme peut soulever à deux mains. La poulie restant ouverte, l'opérateur aura les deux mains libres pour soulever le câble 2, ou pour remettre ce câble ou un autre câble dans la gorge du réa 1.
• b) On peut aussi concevoir, avec un ressort d'ouverture automatique 31 légèrement plus faible, que sous le seul poids du câble 2 la poulie, même déverrouillée, reste fermée, et qu'elle ne s'ouvre que si le câble 2 a été soulevé manuellement, pour être dégagé. Dans ce cas, inversement, la poulie se refermera d'elle-même lorsque le câble sera remis en place dans la gorge du réa 1.

The automatic locking and manual unlocking means could here be carried out as previously, but FIGS. 16 to 18 make it possible to indicate a variant: on the flange 4 which does not carry the sheave 1 is mounted, near the opening 27 receiving axis 6, a pawl 32 mounted pivoting about an axis 33 and subjected to the action of a spring 34. In the same way as the spring 11 of the previous embodiment, this pawl 32 cooperates with the groove 12 and the frustoconical end 13 of the axis 6. Manual action is necessary to pivot said pawl 32, against the force of the spring 34, in order to release the flange 4 and allow it to move apart if the charge is sufficiently reduced. Depending on the force of the spring 31 which acts in the opening direction, various effects can be obtained for the practical use of the pulley:

• a) Spring 31 can be chosen strong enough so that the flange 4 moves away from itself, after manual unlocking, when the load only corresponds to the weight of the cable 2 that a man can lift with both hands. The pulley remaining open, the operator will have both hands free to lift the cable 2, or to put this cable or another cable in the groove of the sheave 1.
• b) It is also conceivable, with a slightly weaker automatic opening spring 31, that under the sole weight of the cable 2 the pulley, even when unlocked, remains closed, and that it only opens if the cable 2 has been lifted manually, to be released. In this case, conversely, the pulley will close by itself when the cable is replaced in the groove of sheave 1.

Of course, in all cases the opening spring 31 must be chosen in such a way that the closing of the pulley, up to the locking position, is perfectly achievable manually by one man, both when the device is suspended by its hook 5 only when it is placed on the ground. However, when the pulley is on the ground (and rests in particular on the ground by its flange 3 carrying the sheave 1), the weight of the device not contributing to the closing, the operator must exert a force slightly greater than that necessary to operate the same manual closing when the device is suspended.

In addition, as shown in FIG. 18, taking into account the spring 31, the opening of the pulley is here necessarily limited by a stop, constituted by a finger 17a of the transverse block 17 which cooperates with part of the flange 3 located at look.

• Dans le cas de la figure 19, où la flasque 4 ne portant pas le réa 1 est liée au crochet 5 par l'intermédiaire d'une traverse 15, une liaison souple est réalisée entre cette flasque 4 et la traverse 15. Dans ce but, un écrou 35 est monté sur le téton 36 de la traverse 15 qui est opposé au téton 19 coopérant avec la lumière 20, l'écrou 35 comprimant une rondelle élastique 37 entre lui-même et la face extérieure de la flasque 4.

Whatever their details, the embodiments of FIGS. 5 to 18 require a very precise adjustment so that the stop means, constituted either by the lugs 18 cooperating with the transverse block 17, or by the light 20 cooperating with the lug 19, completely avoid bending forces in the closed position. These bending forces can be suppressed in addition both the opening pulley, object of the invention, by provisions which will first be explained, in principle, with reference to the diagrams of Figures 19, 20 and 21:

• In the case of Figure 19, where the flange 4 not carrying the sheave 1 is linked to the hook 5 via a cross member 15, a flexible connection is made between this flange 4 and the cross member 15. For this purpose , a nut 35 is mounted on the stud 36 of the cross member 15 which is opposite to the stud 19 cooperating with the slot 20, the nut 35 compressing an elastic washer 37 between itself and the outer face of the flange 4.

In the case of FIG. 20, the connection between the flange 4 and the hook-carrying crosspiece 15 remains rigid. The two ears 8, supporting the axis 9 passing as previously in the cross member 15, here belong to a separate yoke 38, and a flexible connection, always produced by a nut 39 and an elastic washer 40, is provided between said yoke 38 and the flange 3 which carries the sheave 1.

FIG. 21, which again corresponds to a flexible connection produced between the flange 4 not carrying the sheave 1 and the cross-member with hook 15, shows that, as a variant, the axis 9, instead of passing through the cross-member 15, can pass through the upper part of the flange 4.

Figures 22 to 25 show, in detail, an embodiment of an opening pulley produced according to the principle of Figure 19, that is to say with a flexible connection formed between the flange 4 not carrying the sheave 1 and the cross member 15 through which the axis 9 passes. The flanges 3 and 4 being here carried by fittings 14 and 10, this flexible connection is more precisely produced between the fitting 10 and the stud 36 of the cross member 15. It is note that the other stud 19 serves both as a stop means, cooperating with the edge of the light 20 in the closed position, and of a lug cooperating with the profiled spring 21 in the open position. Considering that the aforementioned flexible connection guarantees, in the closed position, the support of the stud 19 under the upper edge of the slot 20, avoiding bending, the axis 9 can be of relatively reduced diameter as shown in the drawing.

Another constructive feature of the embodiment according to FIGS. 22 to 25 lies in the fact that the two ears 8 belong to a yoke 38, distinct from the fitting 14 and fixed to the top of the latter by means of two screws 41 and a rivet 42 which also serves to retain the profiled spring 21.

Finally, FIGS. 26 to 30 show in detail an embodiment similar to the previous one as regards the flexible connection, but in which the articulation axis 9 crosses the upper part of the fitting 10 (according to the principle shown in Figure 21), not the crossbar 15.

Maintaining the pulley in the open position is ensured here by a spring 43 in the shape of a stirrup, the ends of which are linked respectively to the two ears 8, by being freely engaged in holes made on these ears B. The two lateral branches of the spring 43 are articulated around two respective pins 44 and 45, offset with respect to the axis 9, while the middle part of the spring 43 is inserted between, on the one hand, the nut 46 for retaining the hook 5 and , on the other hand, the internal face of the fitting 10. Thus the middle part of the spring 43 slides along the nut 46, during the opening movement and, in the fully open position, as shown in FIG. 30, it is engaged and supported in an annular groove 47 of the nut 46. This groove 47 is obviously shaped in such a way that, under the effect of a load on the cable, the spring 43 disengages from itself to allow automatic closing of the pulley.

In this latter embodiment, the spring 11 has a somewhat modified conformation, which is only an additional variant of the locking means. in the closed position: this spring 11 has a bent end 48 positioned in a small hole in the fitting 10, a rectilinear part located under the fitting 10, between the latter and the flange 4, turns 49 housed in an opening 50 of the fitting 10, and a last curved part situated in front of this fitting 10, this part cooperating with the groove 12 of the axis 6 as well as with a stop 51.

• - Remplacement du crochet 5 par toute suspente équivalente, qui dans tous les cas sera liée à la flasque 4 et/ou au ferrement 10 ne portant pas le réa 1.
• - Montage de deux ou plusieurs réas sur l'axe 6.
• - Réalisation "monobloc" ou en éléments séparés de l'ensemble constitué par la flasque 4 et/ou le ferrement 10, le bloc 17 et le crochet 5, tournant autour de l'axe 9 qui peut traverser cet ensemble monobloc ou la flasque 4 ou le ferrement 10 ou la traverse 15 ou une pièce intermédiaire quelconque, l'axe 9 étant par ailleurs lié par un moyen quelconque-à la flasque 3 et/ou au ferrement 14 portant l'axe 6 du réa 1.
• - Réalisation de la liaison souple entre la flasque 4, ou le ferrement 10, et la traverse 15 portant le crochet 5, ou entre la flasque 3, ou le ferrement 14, et la chape 38 comportant les deux oreilles 8 liées à l'axe d'articulation 9, par tout autre moyen qu'une rondelle élastique pressée par un écrou.
• - Modification de la forme des cliquets 54 et 54a qui assurent à la fois le verrouillage automatique en position fermée et le maintien en position ouverte, ainsi que modification de la position et de l'orientation de l'axe de pivotement de tels cliquets, dont le montage peut se faire, selon le type de poulie ouvrante concerné, sur une flasque, sur un ferrement, ou simultanément sur ces deux organes associés.
• - Remplacement du ressort 21 ou 43 par tout moyen susceptible de maintenir écartées les flasques 3 et 4 malgré l'action du poids de la partie de l'appareil suspendue à l'axe 9 et, éventuellement, du poids d'une certaine longueur de câble 2, mais permettant la fermeture automatique de la poulie ouvrante dès que le câble est mis en place ou quand il est chargé.
• - Conformation du ressort profilé 21 telle que celui-ci puisse maintenir par enclenchement le téton 23 du bloc 17 ou le tourillon 19 de la traverse 15 en position d'ouverture et aussi, éventuellement, en position de fermeture, notamment si l'on n'a pas prévu de système de verrouillage automatique de la poulie fermée.
• - Remplacement du ressort 11 ou du cliquet 32 de verrouillage en position fermée par tout autre moyen de verouilla- ge automatique, coopérant ou non avec l'axe 6 du .réa 1, et éventuellement suppression de tout moyen de verrouillage en position fermée, la poulie restant "de sécurité" par le.fait qu'elle se ferme d'elle-même sous l'effet d'une charge.
• - Adaptation pour l'obtention d'un déchargement automatique, en prévoyant que la poulie s'ouvre d'elle-même lorsque la charge touche le sol ou lorsque la tension sur le câble tend vers zéro.
• - Application à des poulies et moufles ouvrantes avec des réas de toutes dimensions, et avec des flasques et/ ou des ferrements de toutes formes, quelles que soient en outre les techniques de formage et d'assemblage de ces pièces.

It goes without saying that the invention is not limited to the sole embodiments of this opening pulley or block which have been described above by way of examples; on the contrary, it embraces all the variants designed according to the same principles, and it includes in particular all the equivalent means of those described all the derived applications. Thus one would not depart from the scope of the invention by the following modifications or adaptations:

• - Replacement of the hook 5 by any equivalent hanger, which in all cases will be linked to the flange 4 and / or to the fitting 10 not carrying the sheave 1.
• - Assembly of two or more sheaves on axis 6.
• - Realization "monoblock" or in separate elements of the assembly constituted by the flange 4 and / or the fitting 10, the block 17 and the hook 5, rotating around the axis 9 which can pass through this monobloc assembly or the flange 4 or the fitting 10 or the crosspiece 15 or any intermediate piece, the axis 9 being moreover linked by any means-to the flange 3 and / or to the fitting 14 carrying the axis 6 of the sheave 1.
• - Realization of the flexible connection between the flange 4, or the fitting 10, and the cross member 15 carrying the hook 5, or between the flange 3, or the fitting 14, and the yoke 38 comprising the two ears 8 linked to the axis articulation 9, by any other means than an elastic washer pressed by a nut.
• - Modification of the shape of the pawls 54 and 54a which ensure both automatic locking in position closed and keeping it in the open position, as well as modifying the position and orientation of the pivot axis of such pawls, the mounting of which can be done, depending on the type of opening pulley concerned, on a flange, on a fitting, or simultaneously on these two associated members.
• - Replacement of the spring 21 or 43 by any means capable of keeping the flanges 3 and 4 apart despite the action of the weight of the part of the device suspended from the axis 9 and, possibly, the weight of a certain length of cable 2, but allowing the automatic closing of the opening pulley as soon as the cable is put in place or when it is loaded.
• - Conformation of the profiled spring 21 such that the latter can hold the lug 23 of the block 17 or the pin 19 of the cross member 15 in the open position and also, possibly, in the closed position, in particular if n has not provided an automatic locking system for the closed pulley.
• - Replacement of the spring 11 or of the pawl 32 for locking in the closed position by any other automatic locking means, cooperating or not with the axis 6 of the .rea 1, and possibly removing any locking means in the closed position, the pulley remaining "safe" by the fact that it closes by itself under the effect of a load.
• - Adaptation for obtaining an automatic unloading, by providing that the pulley opens itself when the load touches the ground or when the tension on the cable tends towards zero.
• - Application to pulleys and opening blocks with sheaves of all sizes, and with flanges and / or fittings of all shapes, whatever the techniques of forming and assembling these parts.

Claims (21)

1. - Opening pulley or block, of the type comprising two load-bearing flanges, or two load-bearing fittings supplemented by two flanges, one of which supports both the axis of at least one sheave through which a cable passes and, directly or by means of another part, a pivot axis perpendicular to the axis of the sheave and offset, relative to the median plane of the sheave, on the side of the flange not carrying the sheave, this pivot axis carrying itself even, directly or through another part, the flange not carrying the sheave, so that the pivoting of the latter flange around said axis allows the introduction of the cable or its release between the two flanges , while a means of suspending the pulley or the load, such as a hook, the axis of which passes substantially through the median plane of the sheave, is connected to one of the flanges, either directly by a transverse block forming a body with this flange, either indirectly through a part such that e nipple or trunnion, block or this crosspiece being located, relative to the axis of the sheave, on the same side as the opening axis of the pulley or block, characterized in that the hook (5) is connected to the flange (4) not carrying the sheave (1), therefore pivots with this flange (4) relative to the flange (3) which carries the sheave (1), so that the tensile force qu '' a load exerted via the cable (2) on the sheave (1) creates couples whose effect is to bring the two flanges (3,4) imperatively closer to each other, thus closing the pulley / muffle if it was open and now closed for the duration of the application of the force due to the load. 2. - Pulley or block opening according to claim 1, characterized in that stop means (17,18,19,20) are provided, limiting the pivot angle of the assembly "flange (4) not carrying the sheave (1) + hook (5) "relative to the assembly" flange (3) not linked to the hook (5) + sheave (1) ", in the direction of closing the pulley / muffle under the effect of a load, so that the support of an assembly on the other does not generate bending forces that the parts could not support, these means with stop also having the effect of remove, in the closed position of the pulley / block, the transmission of the force due to the load via the pivot axis (9). ₁ 3. - Pulley or block opening according to claim 2, and wherein a transverse block linked to the hook is integral with one of the flanges, characterized in that the support in the closed position is formed between, on the one hand, a face of said transverse block (17) which is integral with the flange (4) not carrying the sheave (1), and on the other hand, at least one lug (18) integral with the flange (3) which carries the sheave ( 1). 4. - Pulley or opening block according to claim 2, and wherein one of the flanges is linked to a hook-carrying cross member, characterized in that said cross member (15), linked to the flange (4) not carrying the sheave (1), has a stud (19) engaged in a lumen (20) of the flange (3) which carries the sheave (1), so that in the closed position of the pulley / block, the support is made! between this stud (19) and the edge of the light (20), the pivot axis (9) passing either through the crosspiece (15) itself, or through the flange (4) not carrying the sheave (1) and linked to said crosspiece (15). 5. - Pulley or block opening according to claim 4, characterized in that the connection between said crosspiece (15), therefore the hook (5), and the flange (4) not carrying the sheave (1), is made with a certain flexibility in a transverse plane, so as to avoid the bending forces of the flanges (3,4) and other parts, in the closed position, under the effect of the load. 6. - Pulley or opening block according to claim 5, characterized in that the flexible connection is produced by means of a nut (35) placed at the end of one (36) studs of the crosspiece (15) and pressing at least one elastic washer (37) against the flange (4) not carrying the sheave (1), or against the bearing fitting (10) of this flange (4). 7. - Pulley or opening block according to claim 4, characterized in that the connection between the pivot axis (9) and the flange (3) carrying the sheave (1) is produced by means of a yoke ( 38), mounted with a certain transverse flexibility on said flange (3) so as to avoid the bending forces of the flanges (3, 4) and other parts, in the closed position, _ under the effect of the load. 8. - Pulley or opening block according to claim 7, characterized in that the flexible connection between the yoke (38) and the flange (3) carrying the sheave (1) is produced by means of at least one elastic washer (40) interposed between these two elements and held by tightening a nut (39). 9. - Pulley or block opening according to any one of claims 1 to 8, characterized in that it comprises, to maintain the two flanges (3,4) spaced from one another in the absence of load due to the load, and to ensure automatic locking when closing the pulley / block under the effect of a load, a single pawl (54, 54a) pivotally mounted on the flange (4) or its fitting carrier (10) linked to the hook (5) and not carrying the sheave (1), said pawl (54, 54a), subjected to the action of a spring (55,55a) tending to rotate it in one direction determined, able to cooperate on the one hand, in the closed position of the pulley / block, with a complementary housing (59, 59a) of an element (8) integral with the flange (3) carrying the sheave (1), and on the other hand, in the open position of the pulley / block, with a bearing surface (60,60a) belonging to this element (8) integral with the flange (3) carrying the sheave (1), said surface d '' support (60,60a) and / or the part (58,58a) d u pawl (54,54a) which cooperates with this surface forming a ramp or a cam which allows, during the application of a load, the sliding of one over the other against the action of the aforementioned spring (55,55a), in the direction of approximation of the two flanges (3,4) of the pulley / block. 10. - Pulley or opening block according to claim 9, characterized in that the pawl (54) is pivotally mounted on the flange (4) or its supporting fitting (10) linked to the hook (5) and not carrying the sheave ( 1) along an axis (53) parallel to the pivot axis (9) of said flange (4), and in that this pawl (54), that the aforementioned spring (55) tends to approach said flange (4 ), comprises on the one hand a lever (56) making it possible to move it away from said flange (4) against the action of the spring (55), and on the other hand a finger (58) capable of cooperating either with a housing (59) or with a boss (60) with a curved profile, both belonging to an element (8) integral with the flange (3) carrying the sheave (1). 11. - Pulley or opening block according to claim 10, characterized in that said element consists of one of the arms (8) of a yoke integral with the flange (3) carrying the sheave (1) and supporting the hinge pin (9) of the other flange (4), one of the edges of this yoke arm (8) having a recess (59) which constitutes the housing of the finger (58) of the pawl (54) locked closing position, and a boss (60) on which rests the same finger (58) of the pawl (54), in the open position of the pulley / block. 12. - Pulley or opening block according to claim 9, characterized in that the pawl (54a) is pivotally mounted on the flange (4) or its supporting fitting (10) linked to the hook (5) and not carrying the sheave ( 1) along an axis (53a) perpendicular to the plane of said flange (4), and in that this pawl (54a) comprises on the one hand an operating lever (56a), and on the other hand a head (58a) at least partially conical in shape, while the complementary element (8) integral with the flange (3) por as the sheave (1) has a part (60a) folded parallel to the latter flange (3), so that the head (58a) of the pawl (56a) can either engage between said folded part (60a) and the flange (4) to its carrying fitting (10) linked to the hook (5), the aforementioned spring (55a) tending to maintain the pawl (54a) in this position, either to press outwards against said folded part (60a) by conical surface. 13. - Pulley or opening block according to claim 12, characterized in that the above-mentioned folded part is constituted by an extension (60a) bent at right angles to one of the arms (8) of a yoke integral with the flange (3 ) carrying the sheave (1) and supporting the hinge pin (9) of the other flange (4). 14. - Pulley or block opening according to any one of claims 1 to 8, characterized in that spring means (21; 31; 43) are provided to keep spaced from one another the two flanges (3 , 4) or to bring the two flanges (3,4) in the separated position and keep them there, until the tensile force exerted by the weight of the cable (2) or of the load, or the weight of the apparatus resting on the cable (2), becomes greater than the resistance of said spring means, and in that other spring means (11; 34) are provided to ensure automatic locking when the pulley is closed / block under the effect of a load, the latter means requiring manual unlocking to allow the opening of the pulley / block. 15. - Pulley or opening block according to claim 14, characterized in that it comprises a spring (21) carried by one of the flanges such as that (3) which carries the sheave (1), or by an integral element of this flange, and able to snap onto an element (23) integral with the other flange such as that (4) linked directly or indirectly to the hook (5) when the two flanges (3,4) are spaced apart. one from the other, to maintain the two flanges (3,4) in this separated position, until voluntary or automatic manual closing under the effect of a load. 16. - Pulley or block opening according to claim 14, characterized in that it comprises an opening spring (31), in particular wound around the axis (9) by which are articulated the two flanges (3,4) and bearing on these two flanges (3,4), so as to tend to separate them and keep them in the separated position, until voluntary manual or automatic closing under the effect of a load. 17. - Pulley or opening block according to claim 14, characterized in that the automatic locking means during closing under the effect of a load, requiring a maruel unlocking, are constituted in the form of a pawl (32 ) pivotally mounted on the flange (4) linked to the hook (5), this pawl being subjected to the action of a spring (34) and cooperating with the free end of the axis (6) of the sheave (1) , carried by the other flange (3), end on which are formed a ramp (13) and a groove (12) capable of receiving said pawl (32). 18. - Pulley or opening block according to claim 14, characterized in that the automatic locking means during closing under the effect of a load, requiring manual unlocking, are constituted in the form of a spring (11 ) fixed on the flange (4) linked to the hook (5) and comprising a curved part cooperating with the free end of the axis (6) of the sheave (1), carried by the other flange (3), end on which are formed a ramp (13) and a groove (12) adapted to receive the curved part of said spring (11). 19. - Pulley or opening block according to claim 15, characterized in that the aforementioned spring, maintaining the two flanges in the separated position, is a profiled spring (21), carried by one of the flanges, such as that (3) which carries the sheave (1), and allowing the engagement of a stud (23) integral with the other flange, such as that (4) linked to the hook (5), when the two flanges (3,4) are spaced from each other. 20. - Pulley or opening block according to claim 15, characterized in that the aforementioned spring, maintaining the two flanges in the separated position, is a caliper-shaped spring (43) whose ends are linked to two ears (8) themselves linked to the flange (3) which carries the sheave (1) and forming a yoke on which the other flange (4) is pivotally mounted linked to the hook (5), the middle part of said stirrup-shaped spring (43) being engaging in an annular groove (47) of the retaining nut (46) of the hook (5), when the two flanges (3,4) are spaced from one another. 21. - Pulley or opening block according to all of claims 4 and 20, characterized in that the stud (19) of the crosspiece (15), engaged in the lumen (20) of the flange (3) carrying the sheave ( 1), also constitutes the stud which, in the open position, engages in the profiled spring (21).

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