EP3816093A1 - Self-locking pulley - Google Patents

Abstract

The pulley (1) comprises a fixing head (2) and a first flange (3). A first shaft (4) extends from the first flange (3). A sheave (5a) is rotatably mounted around the first shaft (4) in a single direction of rotation. A cam (7) is movably mounted to move away from or approach the sheave (5a). A spring (8) is mounted to exert a force moving the cam (7) towards the sheave (5a). A handle (9) is mounted on a first flange (3) for moving the cam (7) between first and second positions.

Description

Technical area

The invention relates to a pulley.

Prior art

In many fields, it is known to use a pulley which consists of a fixing head associated with a sheave mounted for rotation. The pulley is fixed to an anchor point by means of the fixing head. The sheave makes it possible to modify the return force between a load to be lifted and the force applied by the user. A rope connects the load to the user and the rope takes support on the sheave.

There are known pulleys which have two flanges, one flange of which is movable relative to the other flange. The sheave is placed between the flanges. In a particular configuration, the two flanges each define an opening. The two ends of the flanges form the fixing head. The two openings are held together by a carabiner which secures them to the anchor point.

The document US 7,168,687 describes a configuration in which the sheave is installed between two flanges. One of the flanges is fixed to the fixing head while the other flange is mounted to pivot with respect to the first flange. The sheave and the second flange are mounted to move around the same rotation shaft. The second flange is held in the closed position by means of a push button which is partially housed in the fixing head and which is inserted into a through hole of the second flange in order to prevent rotation. Such a configuration does not provide for forming a self-locking pulley, which requires the integration of a rope locking system next to the pulley.

A progress capture pulley with descender is marketed by the company CMC under the name CSR2 PULLEYS and presented in the document US 7,419,138 . The pulley comprises a sheave, the rotation shaft of which is mounted so as to be eccentrically movable with respect to a support flange. The pulley also has a blocker fixedly mounted on the support flange. The rotation shaft of the sheave can be moved by means of a force applied to a lever to bring the rotation shaft closer to the ascender and thus lock the string against the sheave. The sheave is mounted to rotate in a single direction. This solution does not allow not to support significant stresses on the rope so that a slip can occur which generates a heating of the pulley and therefore a lowering of the coefficient of friction between the pulley and the rope.

It also appears that the device marketed by the company CMC under the name MPD ™ Multi Purpose Device does not provide a satisfactory result. Such a product is presented in the document US 7,658,264 and has a pulley mounted movably about an axis of rotation. The pulley is associated with a cam also mounted to move around the same axis of rotation. The pulley is configured so as to allow only one direction of rotation. When a traction on a piece of rope is applied in the second direction of rotation, this causes the blocking of the pulley. The friction between the rope and the pulley causes the rotation of the pulley until the rope jams by means of the cam. It is necessary to have sufficient friction in order to counter the force provided by a resistance spring which places the cam in a position preventing any blocking of the rope. As stated in the document US 7,658,264 , the blocking of the rope is strongly dependent on the friction between the rope and the pulley which leads to a great variability in the quality of the blocking according to the state of wear of the rope and the pulley.

Object of the invention

• une tête de fixation,
• un premier flasque fixé à la tête de fixation,
• un premier arbre de rotation s'étendant depuis le premier flasque,
• un premier réa monté mobile à rotation autour du premier arbre de rotation, le premier réa étant monté mobile à rotation selon un seul sens de rotation,
• une came bloquante montée mobile par rapport au premier réa pour s'éloigner ou se rapprocher du premier réa, la came bloquante étant montée mobile entre une première position et une deuxième position.

An object of the invention is to provide a pulley which is more compact than the configurations of the prior art and which provides efficient locking of the rope. To this end, the pulley comprises:

• a fixing head,
• a first flange fixed to the fixing head,
• a first rotation shaft extending from the first flange,
• a first sheave mounted to rotate around the first rotation shaft, the first sheave being mounted to rotate in a single direction of rotation,
• a locking cam mounted movably relative to the first sheave to move away from or approach the first sheave, the locking cam being mounted movably between a first position and a second position.

• le premier arbre de rotation est monté fixe par rapport au premier flasque,
• la came bloquante est montée mobile par rapport au premier flasque,
• un ressort est monté pour exercer une force déplaçant la came bloquante vers le premier réa,
• une poignée montée sur premier flasque, la poignée étant liée fonctionnellement à la came bloquante pour déplacer la came bloquante entre la première position et la deuxième position.

The self-locking pulley is remarkable in that:

• the first rotation shaft is mounted fixed relative to the first flange,
• the locking cam is mounted to move relative to the first flange,
• a spring is mounted to exert a force moving the locking cam towards the first sheave,
• a handle mounted on a first flange, the handle being operatively linked to the blocking cam to move the blocking cam between the first position and the second position.

In one development, the first sheave comprises a groove defining at least one V-shaped section. Preferably, the first sheave comprises a textured groove, more preferably a faceted groove.

Advantageously, the locking cam is arranged to sink into a groove of the first sheave.

In one development, the locking cam has a textured working surface disposed opposite the groove of the first sheave.

Advantageously, the locking cam is mounted to be movable in rotation around a second rotation shaft mounted fixedly on the first flange or the fixing head.

Preferably, the first sheave is configured to allow rotation according to a first direction of rotation and to prohibit rotation according to a second of rotation opposite to the first direction of rotation. The rotation of the blocking cam in the first direction of rotation causes the blocking cam to move towards the first sheave.

In a particular embodiment, the handle is mounted so as to be able to rotate around a third rotation shaft mounted fixed to the first flange.

Advantageously, the handle is functionally linked to the locking cam by means of a set of gears defining a gear ratio which is preferably different from 1.

In a preferred configuration, the rotation of the handle according to the first direction of rotation causes the rotation of the locking cam according to the second direction of rotation and the rotation of the handle in the second direction of rotation causes the locking cam to rotate in the first direction of rotation.

In an advantageous configuration, the handle comprises a pin cooperating with a stop. The pin is intended to come into contact with the stopper to form a mechanical connection between the handle and the locking cam. The rotation of the handle causes the rotation of the stopper and the rotation of the locking cam.

It is advantageous to provide that the locking cam is associated with a first toothed wheel cooperating with a second toothed wheel forming the stop. In a preferred configuration, the pin passes through a slot provided in the first flange.

Preferably, a second flange is rotatably mounted around the rotation shaft between an open position allowing the insertion or extraction of a string on the first sheave and a closed position prohibiting the insertion or extraction. of the rope, the first sheave separating the first flange and the second flange.

In another development, the self-locking pulley comprises a second sheave mounted movably to rotate around the first rotation shaft, the second sheave comprising a smooth groove and being configured to rotate in the first and second directions of rotation, the second sheave being separated from the first sheave by the first flange.

The subject of the invention is also a hauling system which is compact and which ensures efficient blocking of the rope.

The reeving system comprises a self-locking pulley according to one of the preceding configurations and a pulley device fitted with an additional support flange, an additional rotation shaft projecting from the additional support flange and an additional sheave mounted to rotate around it. the additional rotation shaft, a rope being attached to the self-locking pulley or the additional pulley device and extending between the self-locking pulley and the additional pulley device resting on at least the first sheave and the additional sheave.

Brief description of the drawings

• la figure 1 illustre, de manière schématique, une vue de côté d'une poulie autobloquante;
• la figure 2 représente de manière schématique, une vue en perspective côté d'une poulie autobloquante ;
• la figure 3 représente de manière schématique, une vue de face d'une poulie autobloquante avec une corde montée dans la poulie et la came bloquante appuyant sur la corde ;
• la figure 4 représente de manière schématique, une vue de face d'une poulie autobloquante avec une corde montée dans la poulie et la poignée actionnée pour déplacer la came bloquante à distance de la corde ;
• la figure 5 représente de manière schématique, une vue de face d'une poulie autobloquante sans corde montée dans la poulie, la came bloquante s'insérant dans la gorge du réa ;
• la figure 6 représente de manière schématique, une vue explosée de la poulie autobloquante représentant l'installation du réa ;
• la figure 7 représente de manière schématique une vue en coupe de l'engrenage liant la poignée avec la came bloquante éclatée d'une poulie ;
• la figure 8 représente de manière schématique un dispositif de mouflage comportant la poulie autobloquante.

Other advantages and characteristics will emerge more clearly from the following description of particular embodiments and implementation of the invention given by way of non-limiting examples and shown in the accompanying drawings, in which:

• the figure 1 schematically illustrates a side view of a self-locking pulley;
• the figure 2 schematically shows a side perspective view of a self-locking pulley;
• the figure 3 schematically shows a front view of a self-locking pulley with a rope mounted in the pulley and the locking cam pressing on the rope;
• the figure 4 schematically shows a front view of a self-locking pulley with a rope mounted in the pulley and the handle actuated to move the locking cam away from the rope;
• the figure 5 schematically shows a front view of a self-locking pulley without rope mounted in the pulley, the locking cam inserting into the groove of the sheave;
• the figure 6 schematically shows an exploded view of the self-locking pulley showing the installation of the sheave;
• the figure 7 schematically shows a sectional view of the gear connecting the handle with the exploded blocking cam of a pulley;
• the figure 8 schematically represents a reeving device comprising the self-locking pulley.

Description of the embodiments

As shown on the figures 1 to 8 , the pulley device 1 is advantageously a double pulley device and even more advantageously a pulley or double pulley device for a reeving device. The pulley device 1 forms a self-locking pulley. The pulley device 1 comprises a fixing head 2 which is fixed to a first flange 3. The pulley 1 also comprises a first rotation shaft 4 which extends from the first flange 3. A first sheave 5a is mounted to rotate around it. of the first rotation shaft 4. The first sheave 5a is mounted to move relative to the first flange 3 and relative to the fixing head 2 around the first rotation shaft 4. The first sheave 5a is intended to cooperate with a rope 6. The first rotation shaft 4 defines the axis of rotation of the first sheave 5a. The fixing head 2 defines a ring intended to fix the pulley 1 to an anchoring point, for example by means of a strap, a quick link or a carabiner. The first rotation shaft 4 is advantageously mounted fixed on the first flange 3. The first rotation shaft 4 can be mounted completely fixed or allow its autorotation on the first flange 3. The first flange 3 and / or the fixing head 2 are advantageously made of a metallic material.

The first sheave 5a is mounted to rotate only in a single first direction of rotation around the first rotation shaft 4. The first sheave 5a is configured so as not to be able to perform rotation in the other direction of rotation. The figures 3 and 4 illustrate a pulley device associated with a rope 6. According to the configuration presented, the pulley device 1 is configured to allow the rotation of the first sheave 5a in the counterclockwise direction and to prevent the rotation in the clockwise direction. In other words, the application of a force on the strand of rope 6 according to the arrow A will result in the blocking of the first sheave 5a. The application of a force on the end of the string according to the arrow B must cause the rotation of the first sheave 5a and the displacement of the string 6. The reverse configuration is possible.

According to the embodiments, the first sheave 5a has a smooth groove, or a textured groove. The shape of the groove can be of semi-circular section, but it is advantageous to have a V-shaped section. The groove is advantageously textured in order to promote friction between the string 6 and the first sheave 5a when the first sheave 5a is in a locked position and the rope 6 slides along the first sheave 5a. The friction makes it possible to better control the sliding speed of the string 6 and the contact between the string 6 and the first sheave 5 to place the first sheave 5 in the blocked position. The first sheave 5a and / or at least the groove of the first sheave 5a are advantageously made of a metallic material.

The textured groove may define a plurality of ribs which form constrictions in the groove to facilitate the mechanical connection between the groove and the string 6 which improves possible blockage of the string. The groove can define a plurality of facets or other shapes adapted to define friction.

The first sheave 5a is advantageously devoid of a groove provided with pins which penetrate into the string 6. The pins can be oriented so as to prevent the sliding of the string 6 relative to the first sheave 5a according to the authorized direction of rotation. for the first sheave 5a and to allow sliding of the string 6 when the first sheave 5a is in the blocked position. However, the value of such a configuration is limited.

It is particularly advantageous to have a textured groove in order to ensure a contact which ensures a minimum frictional force between the string 6 and the first sheave 5a. The application of a force on the string in directions A and B results in the actuation of the sheave 5 leading respectively to the blocking of the sheave 5 or to its rotation. The use of a textured groove facilitates obtaining the blocking of the first sheave 5a.

The device comprises a locking cam 7 which is mounted to be movable relative to the first sheave 5a, to the first shaft 4 and to the first flange 3. The locking cam 7 is advantageously mounted to be movable in rotation, in translation or a combination of these two movements.

The locking cam 7 is movably mounted between a first position and a second position so as to approach or move away from the groove. The locking cam 7 approaches or moves away from the bottom of the groove in order to be able to apply a greater or lesser force to the rope 6 placed in the groove. In a first position where the distance between the locking cam 7 and the bottom of the groove of the first sheave 5a is small or minimal, the pressure exerted by the locking cam 7 on the string 6 ensures the locking of the string relative to the first sheave. 5a. The rope 6 cannot slip relative to the first sheave 5a. The application of a force on the string according to the arrow B causes a rotation of the first sheave 5a and a displacement of the string 6. The application of a force on the string according to the arrow A causes a blocking of the sheave 5 this which prevents the movement of the rope 6 according to the arrow A.

In a second position where the distance between the locking cam 7 and the bottom of the groove of the first sheave 5a is large or maximum, the pressure exerted by the locking cam 7 on the string 6 is low or zero, which allows the sliding of the string relative to the first sheave 5a. The application of a force on the string 6 according to the arrow A causes a blocking of the sheave 5 then a slippage of the string 6 relative to the first sheave 5a. The application of a force on the string 6 according to the arrow B causes a rotation of the first sheave 5a and / or a sliding of the string 6 relative to the first sheave 5a and therefore a displacement of the string 6.

Preferably, the locking cam 7 is configured to be able to be introduced between the opposite edges of the groove of the first sheave 5a. The locking cam 7 can be inserted inside the groove to cooperate with a multitude of rope diameters and in particular rope diameters which are much smaller than the maximum diameter defined by the width of the groove. The insertion depth of the locking cam 7 in the groove of the pulley has no effect on the orientation of the pulley device. For example the document US 7,419,138 provides for a rotation of the sheave relative to the attachment point to block the string. The sheave moves as well as the force associated with the mass to be lifted. If the fixing head is designed to have good alignment with the axis of rotation of the sheave during the tensile phases, the alignment cannot be obtained during the blocking phases or vice versa. The devices of the prior art are configured in order to cooperate with a cord of predefined diameter. When the diameter of the rope differs from the recommended diameter by a few millimeters, the device becomes difficult to use. A thicker string causes a problem with insertion in the throat. In contrast, a thinner string greatly reduces the blocking capacity on the sheave. With a locking cam which is introduced into a V-shaped or substantially V-shaped groove to push the string against the sheave, the locking cam ensures sufficient contact between the sheave and the string for very different string diameters. The device is less sensitive to the diameter of the rope and ensures the locking of the rope in the device.

Advantageously, the pulley comprises a spring 8 or an elastic element which is connected to the locking cam 7 on the one hand and to the first flange 3 or to the fixing head 2 on the other hand. The spring 8 applies a stress on the blocking cam 7 which directs the blocking cam towards the first sheave 5a to press the string against the first sheave 5a and possibly block the string 6. The spring 8 is configured so as not to prevent the movement of the sheave. rope 6 when applying a force according to arrow B.

The locking cam 7 is advantageously configured to be a self-locking cam during the application of a force according to the arrow A. In other words, the locking cam 7 is configured to cooperate with the first sheave 5a and block the rope 6 in the direction of arrow A. The cam advantageously comprises a surface texturing which ensures good contact with the string.

The movement of the rope 6 in the second direction (arrow A) causes the movement of the locking cam 7 towards the first sheave 5a which increases the stress applied to the rope 6 and prevents its displacement. Advantageously, the locking cam 7 is mounted to rotate in two directions of rotation. The first direction of rotation of the cam is identical to the first direction of rotation of the first sheave 5a. The rotation of the locking cam 7 in the first direction of rotation causes the locking cam to move closer to the bottom of the first sheave 5a.

Once the rope is locked against the first sheave 5a by means of the locking cam 7 and the first sheave 5a has been locked, it is not possible to slide the rope 6 in the direction of arrow A. The cam must then be actuated. blocking 7 to keep it away from the throat and reduce the force applied to the rope 6.

To facilitate the use of the self-locking pulley 1, it is advantageous to install the locking cam 7 in the half-space which contains the fixing head. The half-space is defined by means of the plane which passes through the axis of rotation of the first sheave and which is perpendicular to the axis connecting the rotation shaft 2 and the fixing head. The cam is located in the portion of the pulley where the rope 6 is in tension and is pressed against the first sheave. However, this configuration limits the possible movement of the locking cam 7.

It is particularly advantageous to use a handle 9 which is operably linked to the blocking cam 7 to move the blocking cam 7. It is advantageous not to mount the handle 9 directly on the blocking cam 7 so as to be able to facilitate the actuation. of the locking cam 7. Advantageously, the locking cam 7 is mounted substantially between the fixing head and the first sheave 5a which improves the compactness of the device but limits its movement. By avoiding direct coupling between the handle and the locking cam, the movement accessible to the handle is different from the movement of the locking cam, which facilitates its use under load.

It is particularly advantageous to take advantage of a reduction between the angle of rotation of the handle 9 and the angle of rotation of the locking cam 7. It is advantageous to provide a mounting of the handle relative to the locking cam 7 which is configured so that a displacement of the handle 9 according to a first angle causes a displacement of the locking cam 7 by a second angle smaller than the first angle in order to have a fine modulation of the force applied by the handle on the position of the locking cam 7. It is also possible to have a configuration where a movement of the handle 9 at a first angle causes a movement of the locking cam 7 by a second angle greater than the first angle. The configuration of the cam is then different.

The mechanical connection between the handle 9 and the locking cam 7 can be made by a rack system as shown in figure 7 . The gear set can define a gear ratio equal to 1 or different from 1. The locking cam 7 has a first set of teeth 7a which cooperates with a second set of teeth 9a mounted on the handle 9. It is advantageous to choose a functional connection between the handle 9 and the locking cam 7 which ensures that a rotation of the distal end of the handle away from the fixation head 2 to approach the rotation shaft 4 results in a removal of the locking cam from the bottom of the groove. In use, the mass to be lifted applies a force to the self-locking pulley which is held in position by means of the fixing head 2. The rotation of the end of the handle 9 to approach the rotation shaft 4 allows the user to apply a force oriented substantially in the same direction as the weight of the mass to be lifted. Consequently, the force applied by the user to the handle to move the locking cam does not drastically modify the orientation of the self-locking pulley.

It is advantageous to use a blocking cam 7 whose surface intended to come into contact with the cord 6 is textured to ensure good contact with the cord and its blocking on the first sheave 5a. It is also advantageous to provide that the locking cam 7 has through recesses in order to be able to evacuate the mud and dust present on the rope and to ensure effective locking over the entire length of the rope.

When the first sheave 5a is blocked, the movement of the handle 9, advantageously in rotation, causes the movement of the locking cam 7 to move away from the groove of the first sheave 5a. The rope 6 disposed between the first sheave 5a and the locking cam 7 sees its constraint decrease until it allows a sliding of the rope 6 relative to the first sheave 5a. By adjusting the position of the handle, it is possible to adjust the value of the friction force between the string and the first sheave 5a and therefore to adjust the sliding speed of the string 6 with respect to the first sheave 5a which is blocked.

In the embodiment illustrated in figures 1 to 8 , the spring 8 ensures continuous contact between the rope 6 and the locking cam 7 in the absence of stress on the handle 9. The force applied to the rope 6 by the locking cam 7 reduces the risk of the rope slipping relative to to the first sheave 5a and therefore ensures immediate or almost immediate blocking of the string 6 with the first sheave 5a and makes it possible to obtain the blocking of the first sheave 5a more quickly.

Advantageously and as illustrated in the figures 1 to 8 , the locking cam 7 is mounted in rotation around a second rotation shaft 10 mounted fixedly on the first flange 3. The spring 8 is preferably a torsion spring mounted around the second rotation shaft 10.

Preferably, the handle 9 is mounted to rotate around a third rotation shaft 11 which is fixedly mounted on the first flange 3.

When the handle 9 and the locking cam 7 are connected by a gear, the latter advantageously has a first toothed wheel 12 defining the teeth 7a of the locking cam 7 and a second toothed wheel 13 defining the teeth 9a of the handle. Depending on the configurations, the first toothed wheel 12 can be monolithic with the locking cam 7 or the second toothed wheel 13 can be monolithic with the handle 9.

It is advantageous that the rotating shaft of the toothed wheel 12 is collinear with the rotating shaft 10 and / or that the rotating shaft of the toothed wheel 13 is collinear with the rotating shaft 11. For example, the handle 9 is mounted on the first flange 3 and has a pin 14. The pin 14 passes through a slot provided in the first flange 3. The pin 14 bears against a toothed wheel 13 which has the teeth 9a. The second rotation shaft 10 is different from the first rotation shaft 4 and is advantageously disposed outside the area occupied by the first sheave 5a. In other words, the two rotation shafts 4 and 10 are separated by a distance greater than the radius of the first sheave 5a. The rotation shafts 10 and 11 are different.

In a particular configuration, the pin 14 is mounted fixed relative to the toothed wheel 12 so that the movement of the handle 9 causes the rotation of the toothed wheel 12 and the teeth 9a and that the movement of the toothed wheel 12 and the teeth 9a trains the displacement of the handle 9. In an advantageous alternative embodiment, the pin 14 is movably mounted in a lumen between two opposite ends of the lumen. The toothed wheel 13 partially covers the slot depending on the position of the blocking cam 7. The position of the toothed wheel 13 is linked to the position of the blocking cam 7. The pin 14 is mounted to move relative to the toothed wheel. 13. The toothed wheel 13 is disposed between the two ends of the light. In this configuration, the movement of the blocking cam 7 causes the movement of the toothed wheel 13 independently of the position of the pin 14. The insertion of the rope 6 between the blocking cam 7 and the groove causes a movement of the blocking cam 7 but does not cause the movement of the pin 14 and does not cause the movement of the handle 9. The spring 8 presses the locking cam 7 against the string 6. To reduce the intensity of the force applied to the string 6 by the locking cam 7, it is necessary to actuate the handle 9 from its first position which corresponds to a rest position to an engagement position where the pin 14 comes into contact with the toothed wheel 13 in a first direction of movement of the handle 9. From the engagement position, the movement of the handle 9 causes the movement of the toothed wheel 13 and the movement of the locking cam 7. It is particularly advantageous to provide that the handle 9 comprises a pin 14 cooperating with stubborn to mechanically link the handle with the blocking cam 7. The pin 14 is intended to come into contact with the stopper to form a mechanical connection between the handle 9 and the blocking cam 7 and the rotation of the handle 9 causing the stopper to rotate and the rotation of the locking cam 7.

The teeth 9a engage with the teeth 7a and cause the locking cam 7 to rotate.

The spring 8 is configured to apply a force to the locking cam 7 to return the locking cam 7 to the first position. At the same time, the spring 8 moves the handle 9 into a first position representative of the first position of the locking cam 7.

Advantageously, the pulley 1 comprises a second flange 15 which is mounted to rotate around the rotation shaft 4. The second flange 15 is mounted to rotate relative to the first flange 3. The second flange 15 has an internal face and an external face. The first sheave 5a faces the internal face of the second flange 15. The first sheave 5a is arranged between the first flange 3 and the second flange 15 in the direction of the axis of rotation. The second flange 15 defines a first position which cooperates with the fixing head to close the pulley 1. The second flange 15 also defines a second position which corresponds to an open position of the pulley 1.

Preferably, the second flange 15 is provided with a friction member 16 which defines a groove intended to receive the string at the output of the first sheave 5a. The friction member 16 and the first sheave 5a are separated by the second flange 15.

Advantageously, the pulley comprises a second sheave 5b which is rotatably mounted on the rotation shaft 4 or on an additional rotation shaft which is advantageously collinear with the rotation shaft 4. The two sheaves 5a and 5b are separated. by the first flange 3 and can rotate independently of each other. Advantageously, the second sheave 5b is configured to be able to rotate in both directions of rotation. The second sheave 5b is advantageously a smooth groove sheave to reduce the friction between the string 6 and the pulley 1.

The second sheave 5b is advantageously devoid of an association with a system for blocking the rope 6, for example by blocking cam.

As indicated above, the pulley device 1 can be part of a reeving device as illustrated in figure 8 wherein the pulley device 1 cooperates with an additional pulley device which also comprises one or more pulleys mounted on one or more support flanges which are associated with a fixing head. The additional pulley device is advantageously different from the pulley device described above, for example by being provided only with smooth-groove sheaves and / or by being devoid of rope locking means.

A rope runs alternately between the sheaves of the pulley device and the additional pulley device to connect them mechanically. One of the pulley device and the additional pulley device is connected to an anchor point and the other device is connected to a mass to be lifted. The user pulls on the rope 6 in order to lift the mass, which corresponds to a tensile force according to the arrow B. When the user stops requesting the rope, 6 the mass applies a force according to the arrow A which blocks the first sheave 5a. The rope 6 is blocked by the locking cam 7 against the first sheave 5a.

By actuating the handle 9, the user moves the locking cam 7 relative to the sheave 5a and more precisely relative to the groove to reduce the stress applied to the rope 6. When a threshold position is reached, the rope 6 can be pulled back. move by sliding on the first sheave 5ab. In this case, it is advantageous to use a textured sheave to provide friction and better control the running speed of the rope 6 as a function of the position of the locking cam 7.

It is particularly advantageous to have a pulley 1, the rotation shaft 4 of which is fixed relative to the first flange 3 because this reduces or avoids the displacement of the sheave 5a between the phases of traction on the rope and the blocking phases. This also makes it possible to increase efficiency during the traction phases. The rotation shaft 4 being mounted fixed on the first flange 3, this makes it possible to facilitate the integration of the sheave 5a in the pulley device 1 and to gain in compactness.

The sheave 5a is circular or substantially circular and turns in order to follow the movement of the string during a force according to the arrow B which improves the efficiency during the tensile phases by taking advantage of the low friction forces provided by the sheave 5a in comparison of a conventional belay device which has a lot of friction.

The pulley device 1 is configured so as to define a rope circulation path almost exclusively formed by the first sheave 5a. In other words, the rope circulating in the pulley device follows the shape of the pulley over half of its perimeter or substantially half of its perimeter to form a semicircle or almost a semicircle. As indicated above, on this semicircle, the string takes advantage of the low friction provided by the sheave 5a. Under load, the rope 6 passes through the pulley device without leaning on a fixed element introducing friction other than the locking cam 7. The locking and unlocking of the rope is effected by moving the movable cam 7 relative to the sheave. 5a and relative to the first flange which makes it possible to reduce the movements of the pulley relative to the anchoring point between the traction phases and the locking phases.

In the illustrated embodiment, the pulley device 1 is configured so that the first sheave 5aa and the locking cam 7 are the only points of continuous contact with the rope to ensure minimum friction and therefore high efficiency. The pulley device is preferably configured so that the first flange has no projecting zone towards the first sheave 5a out of the half-space defined by the plane passing through a diameter of the first sheave 5a and perpendicular to the axis connecting the axis of rotation of the first sheave 5a and the fixing head 2. The rope 6 can move freely without rubbing against the first flange 3.

The blocking cam 7 is mounted so as to move closer to or away from the first sheave 5a which allows a movement of the blocking cam 7 to follow the movements of the rope 6 at the exit of the first sheave 5a (according to arrow B) and reduce the friction induced by the locking cam 7. In comparison, in a conventional belay device, the rope slides on a movable cam in rotation and a not insignificant friction is sought in order to move the cam according to the direction of movement of the rope. rope. For example, the document US 2014/0262611 suggests using a belay device with a pulley. Like all belay devices, a certain level of friction is introduced by the multiple fixed zones on which the rope slides. The pulley is used in association with a blocking system beyond a threshold speed representative of a fall to modulate the frictional force and block the rope. In such a configuration, when the user pulls on the rope, the efficiency is low because the friction is high.

The pulley 1 preferably comprises a locking mechanism configured to lock the second flange 15 in the first position relative to the first flange 3. In the closed position, the rope or the cable installed in the pulley 1 cannot be extracted. It is also not possible to install a rope or cable. In the open position, it is possible to install a cable or a rope between the two flanges 3 and 15 and advantageously in contact with the first sheave 5a.

The locking mechanism may have a rod 17 fixed to the first flange 3 or to the fixing head 2. The rod 17 is mounted movably between a first position and a second position according to a first movement. The first movement may be a translational movement or a rotational movement or a combination thereof. The first movement is advantageously not a translation of the rod 17 parallel to the axis of rotation of the first sheave 5a.

In the first position, the rod 17 engages with the second flange 15 to hold the second flange 15 in the first position. In the second position, the rod 17 allows the rotation of the second flange 15. The rod 17 protrudes from the external face of the second flange 15. The second flange 15 can be formed from metallic material or from plastic material. The rod 17 can be formed of metallic material or of plastic material

The pulley 1 comprises a shutter 18 fixed to the second flange 15 and mounted to move between a first position and a second position according to a second movement different from the first movement. The first movement is different from the second movement which forces the user to perform two consecutive and different movements to actuate the shutter 18 then actuate the actuating rod 17 in order to then perform the rotation of the second flange 15. The use of two different consecutive movements on two separate elements makes it possible to reduce or even avoid the disengagement of the rod 17 in comparison with a single disengagement movement of the rod 17.

The shutter 18 is configured to at least partially cover the rod 17 so as to prevent the actuation and therefore the displacement of the rod 17 from the first position to the second position. By covering the rod 17, the shutter 18 prevents the user from coming into contact with the rod 17 and thus prevents the user from moving the rod 17 from the first position to the second position. The shutter 18 is not configured to hold the second flange 15 in the first position by a mechanical connection. The shutter 18 installed on the outer face of the second flange 15 is not in direct contact with the first flange 3 and is not directly involved in maintaining the second flange 15 in the closed position.

Preferably, the movement of the shutter 18 from the first shutter position to the second shutter position takes place in a first direction of movement which is opposite to the second direction of movement of the rod 17 during the movement of the rod 17 from the first rod position to the second rod position. The first direction of movement of the shutter can be a movement towards the rotation shaft 4 while the second direction of movement can be a movement away from the shaft 4. The reverse configuration is also possible.

The illustrated configuration allows a user's finger to come into contact with the shutter 18. The finger moves in the first direction of movement in order to move the shutter 18 and make the rod 17 accessible. Having become accessible, the user's finger returns to its starting position by moving in the second direction opposite to the first direction. The finger comes into contact with the rod 17 and moves the rod 17 from the first position to the second position to release the second flange 15 and allow its rotation. The finger can apply a third movement to move the second flange 15. The finger can press the shutter 18 to cause the rotation of the second flange 15.

It is advantageous to use a rotary shutter 18 because this facilitates its implementation and its movement with a single finger. It is also advantageous to combine a rotary shutter with a translational rod because this facilitates the disengagement of the rod when the finger returns in the second direction of movement.

Advantageously, the second flange 15 defines a first end stop which is configured to stop the movement of the shutter 18 which moves in the first direction. Once the shutter 18 reaches the first end stop, the application of a force in the first direction results in the rotation of the second flange 15 relative to the first flange 3 when the rod 17 is in the second position. If the rod 17 is in the first position, the force applied to the shutter 18 is prevented by the mechanical connection which exists between the rod 17 and the second flange 15. The shutter 18 is advantageously mounted to rotate on a rotation shaft. 19 fixedly mounted on the second flange 15.

Advantageously, the second flange 15 defines a second end stop which defines the first position and / or which is configured to prevent, in its first position, the shutter 18 from coming into direct contact with the rod 17. The second end stop is configured to prevent the movement of the shutter 18 beyond its first position in the second direction of movement. By preventing the movement of the shutter 18, an involuntary movement of the shutter 18 according to the second movement is impossible, which prevents the movement of the rod 17 by means of the shutter 18.

Preferably, the shutter 18 is rotatably mounted which facilitates the movement of the shutter 18 with a single hand and advantageously with a single finger.

In an advantageous configuration, a spring (not shown) is connected to the second flange 15 and to the shutter 18. The spring is configured to return the shutter 18 to its first position. The spring ensures increased safety because the shutter 18 naturally returns to its first position to cover the rod 17. Advantageously, the shutter 18 is separated from the second flange 15 by the end of the rod 17. Preferably , the spring is separated from the first flange 3 by the second flange 15.

Advantageously, an additional spring (not shown) is connected on the one hand to the fixing head 2 or to the first flange 3 and on the other hand to the rod 17. The additional spring is configured so that the rod 17 is returned. in the first position in the absence of solicitation.

In a particular configuration illustrated, the shutter 18 has a shutter zone covering the rod 17 in the first rod position. In its first position, the closure zone faces the rod 17 along the axis of rotation of the shaft 4. Preferably, when the rod 17 is in the second position (allowing the rotation of the second flange 15), the rod 17 is visible independently of the position of the shutter 18, which allows the user to observe that the second flange 15 will not be kept in the closed position, which improves the operating safety of the pulley.

When the rod 17 and the shutter 18 are both in the first position and the second flange 15 is closed, the shutter 18 covers the rod 17 in the direction of the axis of rotation which prevents its unwanted actuation. .

Preferably, the rod 17 is terminated by a gripping zone having an enlarged section with respect to a section of the rod 17 engaging with the second flange 15. The shutter 18 has a closing zone completely covering the gripping zone. in a direction parallel to the axis of rotation of the second flange 15 relative to the first flange 3.

Advantageously, the gripping zone is covered by a colored indicator having a color different from the color of the shutter 18 and from the color of the first flange 3. The shutter zone completely masks the colored indicator when the rod 17 and the shutter are in the first position and the pulley is closed. The masking is observed in a direction of observation parallel to the axis of rotation of the second flange 15 relative to the first flange 3. The use of a colored indicator makes it possible to quickly detect that the shutter 18 is not. arranged, relative to the actuating rod 7, in a position representative of the maintenance of the pulley 1 in the closed position.

In an advantageous configuration, the second flange 15 defines a sliding ramp for the rod 17. When moving the second flange 15 from the open position to the closed position, the rod 17 comes into contact with the sliding ramp which moves the rod 17 out of its locking position. Thus, when the second flange 15 returns to its closed position, the user is able to quickly and visually detect that the second flange 15 has not yet reached the closed position, which improves safety. Once the closed position is reached, the rod 17 leaves the ramp to cooperate with a hook defined in the side wall of the second flange.

In a preferred configuration, the displacement of the rod 17 from the first position to the second position corresponds to a distance of the rod 17 relative to the rotation shaft 4. The rod 17 moves at least according to a component perpendicular to the axis. 'axis of rotation between the two flanges 3 and 6. Advantageously, the rod 17 moves only in a plane perpendicular to the axis of rotation of the flange 15, for example in rotation, in translation.

Advantageously, the shutter 18 is mounted to rotate around a rotation shaft 19 fixed to the second flange 15. The shaft 19 moves during the rotation of the second flange 15.

In a particular embodiment, the second rotation shaft 19 protrudes from the internal face of the second flange 15. Preferably, the fixing head 2 defines a groove 20 cooperating with the second rotation shaft 19 to form a stopper. limit switch during a rotation of the second flange 15 from the second position to the first position. When closing the pulley 1, the second flange 15 pivots and the second rotation shaft 19 comes into contact with the groove 20 and slides along the groove 20 until reaching the end stop which defines the first position of the second flange 15.

The second rotation shaft 19 is mounted on the second flange 15 which facilitates the actuation of the shutter 18. The actuation of the shutter 18 can be performed independently of the position of the second flange 15 relative to the first flange 3. The shutter 18 is mounted to rotate with respect to the second flange 15 around the second rotation shaft 19 and the second rotation shaft 19 is mounted to be movable in rotation with respect to the first flange 3.

In an advantageous configuration, the groove 20 has a lateral dimension adjusted to the lateral dimension of the second rotation shaft 19 in order to absorb the force between the fixing head 2 and the second flange 15. In this configuration, the force applied by the cord on the first sheave 5a may result in a deflection of the rotation shaft 4. In order to be able to withstand greater forces, it is advantageous to provide that the second flange 15 is mechanically connected to the first flange 3 by means of a second mechanical connection different from the rotation shaft 4. The second mechanical connection is provided by the second rotation shaft 19 which engages in the fixing head 2 or in the first flange 3. The force applied to the first sheave 5a is distributed over the two flanges 3 and 15.

In the particular configuration illustrated, the second flange 15 has a side wall defining a hook or a recess engaging with the rod 17. Once the rod 17 is blocked in the hook or the recess, the second flange 15 remains in the closed position. which prevents its rotation. The side wall connects the internal face with the external face.

In a particular embodiment, the first flange 3 is made monolithically with part of the fixing head 2. Advantageously, the fixing head 2 is rotatably mounted about an axis of rotation which is perpendicular to the 'rotation axis.

In the embodiment illustrated on figure 6 , the first sheave 5a is mounted on a bearing 20, for example a ball bearing which is connected between the rotation shaft 4 and the first sheave 5a. An adapter can be mounted on the shaft 4 to better define the rotation of the first sheave 5a.

The figure 2 illustrates a pulley 1 in the closed position with the rod 17 and the shutter 18 each in the first position. The two flanges 3 and 15 are mechanically connected by means of the first shaft 4 and the rod 17. The shutter 18 completely covers the rod 17 to prevent its inadvertent actuation. The second flange 15 is held in the closed position by means of the rod 17. The handle 9 is located between the first position and the second position, in a position which places the locking cam in an intermediate position. In the intermediate position, the force applied by the locking cam 7 on the string is weak or even zero so as to allow the sliding of the string relative to the first sheave 5a, the intensity of the force depends on the diameter of the string used.

The figures 3 and 4 illustrate the movement of the locking cam 7 relative to the rope 6 as a function of the position of the handle 9. The figure 5 illustrates the insertion of the locking cam 7 inside the groove of the sheave 5 in a particular embodiment when the handle is in the first position.

The figures 5 and 6 illustrate a particular embodiment of a mechanism ensuring the rotation of the sheave 5a in a single direction of rotation. The figure 6 illustrates a configuration using two blockers 21 which cooperate with cavities arranged inside the sheave 5a, but other configurations are possible. The figure 6 shows an exploded view of the pulley 1 with the assembly of the sheave 5a on a ball bearing 22 around the shaft 4.

The figure 7 illustrates the particular integration of the two toothed wheels 12 and 13 in part of the thickness of the first flange 3.

As shown in figure 7 , the pulley may comprise a second sheave 5b and a second additional flange 15 which is separated from the first flange 3 by the second sheave 5b and the second additional flange 15 is mounted to be movable in rotation around the rotation shaft of the second sheave 5b. The second additional flange 15 is mounted to rotate relative to the first flange 3 and to the fixing head 2. The second additional flange 15 has an inner face and an outer face. The second sheave 5b faces the internal face of the second additional flange 15. The second additional flange 15 is advantageously mounted identically to the second flange 15.

The second additional flange 15 can be opened independently of the second flange 15.

The pulley 1 also has a second locking mechanism configured to lock the second additional flange 15 in the first position relative to the first flange 3. In the closed position, the rope or cable installed in the pulley 1 or cannot be extracted. . It is also not possible to install a rope or cable. In the open position, it is possible to install a cable or a rope between the first flange 3 and the second additional flange 15. The ropes installed in the pulley are separated by the first flange 3.

The additional locking mechanism has an additional rod 7 fixed to the first flange 3 or to the fixing head 2. The additional rod 7 is mounted to move between a first position and a second position according to a first movement. The first movement may be a translational movement or a rotational movement or a combination thereof. The first movement is not a translation of the additional rod along the axis of rotation of the shaft 4.

In the first position, the additional rod engages with the second additional flange 15 to hold the second additional flange 15 in the first position. In the second position, the additional rod allows rotation of the second additional flange 15. The additional rod protrudes from the outer face of the second additional flange 15. Advantageously, in the second position, the additional rod 15 is not in contact with it. the second additional flange 6. The actuation of the additional rod according to the first movement makes it possible to pass from the first additional rod position to the second additional rod position according to a first direction of actuation and from the second additional rod position to the first additional rod position in a second direction of actuation opposite to the first direction of actuation. The first movement can be a rotation or a translation. The assembly of the additional rod can take one of the multiple configurations of the rod described above.

An additional shutter is mounted on the second additional flange 15. According to one of the configurations already presented for mounting the shutter 18 on the second flange 15. The opening of the second flange 15 is performed independently of the opening of the second. additional flange 15.

Advantageously, the rotation shaft 10 of the locking cam is fixed on one side to the first flange 3 and on the other side to the fixing head 2 by means of a support plate 23 as illustrated in the figures. figures 2 to 7 .

The figure 8 shows an embodiment of the reeving system in which the pulley device described above cooperates with another pulley device. The rope connects the pulley device and an additional pulley device. The additional pulley device comprises one or more sheaves which are advantageously sheaves configured to rotate in both directions. The sheaves are preferably with a smooth groove. It is preferable to provide for the sheaves to be mounted for rotation around an axis of rotation and possibly around the same rotation shaft 24. The additional pulley device is provided with a support flange 3, a shaft. of additional rotation 24 projecting from the support flange 3 and an additional sheave mounted to rotate around the additional rotation shaft. A rope 6 extends between the self-locking pulley and the additional pulley device, resting on at least the first sheave 5a and the additional sheave.

In the illustrated embodiment, the additional pulley device is made substantially identical to the pulley device described above. It is nevertheless advantageous that the additional pulley device is devoid of a locking cam to facilitate its use. Preferably, the additional pulley device comprises a first flange 3 associated with a fixing head 2. The additional pulley device advantageously has one or more second flanges 15 mounted to rotate, for example to rotate around the axis of rotation of the sheaves. . The second flanges can be held in position by means of a fixing system equivalent to that described above and advantageously with a rod hidden by a shutter 18 to prevent its unintentional opening.

One of the ends of the rope 6 is fixed to the pulley device or to the additional pulley device, for example with a knot or a seam. Rope 6 runs alternately from the pulley device to the additional pulley device passing over the sheaves until leaving the additional pulley device or the pulley device. It is advantageous for the free end of the rope to leave the reeving system by leaving the pulley device and preferably the first sheave 5a in order to be in contact with the first sheave 5a and the locking cam 7.

By pulling on the free end of the rope 6, the additional pulley device and the pulley device move closer together which lifts a load. Preferably, the pulley device is hooked to an anchoring point so that the handle 9 does not move according to the distance between the pulley device and the additional pulley device.

Claims (16)

Self-locking pulley (1) comprising: - a fixing head (2), - a first flange (3) fixed to the fixing head (2), - a first rotation shaft (4) extending from the first flange (3), - a first sheave (5a) mounted to be movable in rotation around the first rotation shaft (4), the first sheave (5a) being mounted to be movable in rotation in a single direction of rotation, - a locking cam (7) mounted to move relative to the first sheave (5a) to move away from or approach the first sheave (5a), the locking cam (7) being mounted to move between a first position and a second position, self-locking pulley (1) characterized in that : - the first rotation shaft (4) is mounted fixed relative to the first flange (3) and to the fixing head (2), - the locking cam (7) is mounted to move relative to the first flange (3) and to the fixing head (2), - a spring (8) is mounted to exert a force on the locking cam (7) moving the locking cam (7) towards the first sheave (5a), - a handle (9) mounted on the first flange (3) or on the fixing head (2), the handle (9) being operatively linked to the locking cam (7) to move the locking cam (7) between the first position and the second position. Self-locking pulley (1) according to claim 1, wherein the first sheave (5a) has a groove defining at least one V-shaped section. Self-locking pulley (1) according to claim 2, in which the first sheave (5a) comprises a textured groove, preferably a faceted groove. Self-locking pulley (1) according to one of claims 2 and 3, in which the locking cam (7) is arranged to sink into a groove of the first sheave (5a). Self-locking pulley (1) according to the preceding claim, in which the locking cam (7) has a textured working surface disposed opposite the groove of the first sheave (5). Self-locking pulley (1) according to one of the preceding claims, in which the locking cam (7) is mounted so as to be able to rotate around a second rotation shaft fixedly mounted on the first flange (3) or the fixing head (2 ). Self-locking pulley (1) according to the preceding claim, in which the first sheave (5a) is configured to allow rotation in a first direction of rotation and to prohibit rotation in a second rotation opposite to the first direction of rotation and in which the rotation of the locking cam (7) in the first direction of rotation causes the locking cam (7) to move towards the first sheave (5a). Self-locking pulley (1) according to one of the preceding claims, in which the handle (9) is mounted so as to be able to rotate around a third rotation shaft (11) mounted fixed on the first flange (1). Self-locking pulley (1) according to the preceding claim, in which the handle (9) is operably linked to the locking cam (7) by means of a set of gears (12, 13) advantageously defining a gear ratio different from 1. Self-locking pulley (1) according to one of claims 8 and 9, wherein the rotation of the handle (9) according to the first direction of rotation causes the rotation of the locking cam (7) according to the second direction of rotation and the rotation of the handle (9) according to the second direction of rotation causes the rotation of the locking cam (7) according to the first direction of rotation. Self-locking pulley (1) according to one of claims 8 to 10, in which the handle (9) comprises a pin (11) cooperating with a stop, the pin (11) being intended to come into contact with the stop to form a mechanical connection between the handle (9) and the locking cam (7) and the rotation of the handle (9) causing the rotation of the stopper and the rotation of the locking cam (7). Self-locking pulley (1) according to the combination of claims 9 and 11, in which the locking cam (7) is associated with a first toothed wheel (12) cooperating with a second toothed wheel (13) forming the stop. Self-locking pulley (1) according to the preceding claim, in which the pin (14) passes through a slot provided in the first flange (3). Self-locking pulley (1) according to one of the preceding claims, in which a second flange (15) is rotatably mounted around the first rotation shaft (4) between an open position allowing the insertion or extraction of a rope (6) on the sheave (5b) and a closed position preventing the insertion or extraction of the string (6), the sheave (5a) separating the first flange (3) and the second flange (15). Self-locking pulley (1) according to one of the preceding claims, comprising: - a second sheave (5b) mounted so as to be able to rotate around the first rotation shaft (4) mounted fixedly relative to the first flange (3) and to the fixing head (2), the second sheave (5b) comprising a smooth groove and being configured to rotate in the first and second directions of rotation, the second sheave (5b) being separated from the first sheave (5a) by the first flange (3). Reeving system comprising a self-locking pulley (1) according to one of the preceding claims and an additional pulley device provided with an additional support flange, an additional rotation shaft projecting from the additional support flange and an additional sheave mounted at rotation around the additional rotating shaft, a rope being attached to the self-locking pulley or the additional pulley device and extending between the self-locking pulley and the additional pulley device resting on at least the first sheave (5a ) and the additional sheave.

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