EP4034272B1 - Pulley with single-direction travel - Google Patents

Description

Technical area

The invention relates to a pulley.

Prior art

In adventure parks, going down a zip line is a popular activity. The practitioner installs the pulley on a cable so as to slide along the cable from the starting area to the finishing area.

The tension applied on the cable between the start zone and the finish zone is configured so that an average weight user can reach the finish zone with low momentum. The tension applied to the cable is low enough that a slack zone exists just before the arrival zone.

The result is that the cable rises close to the arrival zone and the user ascends along the cable thanks to the speed acquired during the descent. However, when the practitioner is not heavy enough, the speed acquired is not sufficient for the latter to reach the finish zone. This results in the pulley slowing down as it gets closer to the finish area until it stops and then moves in the other direction.

To avoid this inconvenience and facilitate the recovery of the user, it is particularly advantageous to provide a pulley which is equipped with an anti-return system. The anti-return system is configured to authorize the circulation of the pulley on the cable in a first direction of circulation and to prevent circulation in the other direction.

Such a pulley is described in the document US 2016/0355197 which provides for the use of a rotating cam. In circulation along the cable, the axis of rotation of the cam is substantially horizontal and perpendicular to the longitudinal axis of the cable.

When the pulley moves in the forward direction, the friction between the cable and cam causes the cam to rise to slide along the cable. When the pulley is subjected to a force that encourages it to move in a backward direction, the cam is not encouraged to lift relative to the cable. On the contrary, the contact surface between the cam and the cable increases which increases the friction between the cam and the cable. The cam is shaped in a self-locking manner so as to block the pulley and thus prevent movement in the rearward direction. The cam lifts the rear sheave off the pulley. It appears that this construction is not as simple to install as it appears so that the effectiveness of the cam is strongly dependent on the diameter of the associated cable. As there are many standards for cable diameters between 12 and 13mm, the operation of the pulley varies significantly from one installation to another.

Another configuration was proposed by the company BORNACK which markets a pulley having a roller configured to only rotate in one direction. This solution is not interesting because it is expensive and strongly dependent on the friction which exists between the cable and the roller, that is to say it is very difficult or even impossible to have effective blocking by means of a roller that slides along the cable.

Object of the invention

• une paire de réas disposés en ligne, la paire de réas possédant des gorges définissant un axe de circulation du câble dans la poulie et correspondant à l'axe longitudinal du câble,
• un bloqueur mobile entre une première position autorisant le déplacement de la poulie selon l'axe longitudinal du câble selon un premier sens et une deuxième position empêchant le déplacement de la poulie selon un deuxième sens opposé, le bloqueur définissant une rainure destinée à coopérer avec le câble, la rainure comportant des première et deuxième parois latérales opposées reliées par une paroi de fond, le bloqueur étant disposé de sorte que l'axe de circulation du câble passe entre les deux parois latérales.

An object of the invention consists of providing a pulley provided with an anti-return system which is easy to implement, economical while ensuring effective blocking of the pulley in the reverse direction. For this purpose, the pulley comprises:

• a pair of sheaves arranged in a line, the pair of sheaves having grooves defining an axis of circulation of the cable in the pulley and corresponding to the longitudinal axis of the cable,
• a movable blocker between a first position allowing movement of the pulley along the longitudinal axis of the cable in a first direction and a second position preventing movement of the pulley in a second opposite direction, the blocker defining a groove intended to cooperate with the cable, the groove comprising first and second opposite side walls connected by a bottom wall, the blocker being arranged so that the axis of circulation of the cable passes between the two side walls.

The pulley is remarkable in that at least the first side wall is movable along the axis of circulation of the cable and in that the movement of the blocker between the first position and the second position corresponds to a movement of the first side wall according to the second direction to offset the first and second side walls along the axis of circulation of the cable and block the pulley on the cable by bracing.

In one development, the blocker is mounted free in a direction perpendicular to the axis of circulation of the cable and perpendicular to the axes of rotation of the sheaves, the weight of the blocker driving one of the side walls of the groove or the bottom wall towards the cable circulation axis.

Advantageously, the blocker is arranged so that the weight of the blocker brings the bottom wall and the axis of circulation of the cable closer together.

Preferably, the first and second side walls are mounted movable along the axis of circulation of the cable, when the blocker moves from the first position to the second position, the distance of movement of the first side wall is greater than the distance of movement of the second distance along the axis of circulation of the cable.

In a particular embodiment, the pulley is configured to cooperate with a cable of a first diameter and in which the separation distance between the first and second side walls is greater than the first diameter at least over a height greater than half of the first diameter so that the first and second side walls are separated by a diameter of the cable in the first position and in the second position.

Advantageously, the pulley comprises a housing housing the blocker, the housing defining stops limiting the movement of the first side wall and the second side wall along the axis of circulation of the cable in the first direction.

In a preferred configuration, the housing and the blocker define a functional clearance in a direction passing through the two side walls of the groove and the axis of circulation of the cable.

Preferably, the housing and the blocker define a functional clearance in a direction passing through the bottom wall and the axis of circulation of the cable.

In another development, the blocker is mounted removable relative to the housing.

Preferably, the housing prevents the rotation of the blocker around an axis of rotation parallel to the axes of rotation of the sheaves.

In a particular embodiment, the housing is mounted stationary relative to a support bracket supporting the sheaves when the blocker moves between the first and second positions.

In an advantageous configuration, the box is mounted removable relative to a support bracket supporting the sheaves.

Preferably, the housing defines first and third stops limiting the movement of the first side wall of the blocker along the axis of circulation of the cable and second and fourth stops limiting the movement of the second side wall of the blocker along the axis of circulation of the cable, the distance between the second and fourth stops being less than the distance between the first and third stops along the axis of circulation of the cable.

In another development, the housing defines first and second stops configured to form a support plane of the blocker in the first position perpendicular to the axis of circulation

Summary description of the drawings

• la figure 1 illustre, de manière schématique, en perspective, un premier mode de réalisation d'une poulie avec un dispositif anti-retour ;
• la figure 2 illustre, de manière schématique, en perspective, un second mode de réalisation d'une poulie avec un dispositif anti-retour ;
• la figure 3 illustre, de manière schématique, une poulie avec une vue éclatée du dispositif anti-retour ;
• la figure 4 illustre, de manière schématique, en vue de coupe selon le plan A-A au niveau du dispositif anti-retour ;
• la figure 5 illustre, de manière schématique, en vue de côté une poulie munie d'un dispositif anti-retour ;
• la figure 6 représente, de manière schématique, en vue de dessus et en coupe dans le dispositif anti-retour selon le plan B-B, une poulie dont le dispositif anti-retour est dans une position de circulation ;
• la figure 7 représente, de manière schématique, en vue de dessus et en coupe dans le dispositif anti-retour selon le plan B-B, une poulie dont le dispositif anti-retour est dans une position de blocage,
• la figure 8 représente, de manière schématique, en vue de face, une poulie dont le dispositif anti-retour est dans une position autorisant le déplacement, le câble étant sensiblement rectiligne,
• la figure 9 illustre, de manière schématique, en vue de côté et en coupe dans le dispositif anti-retour selon un plan C-C, une poulie munie d'un dispositif anti-retour dans une position autorisant le déplacement, le câble étant sensiblement rectiligne;
• la figure 10 représente, de manière schématique, en vue de face, une poulie dont le dispositif anti-retour est dans une position autorisant le déplacement avec le câble plié par la poulie,
• la figure 11 illustre, de manière schématique, en vue de côté et en coupe dans le dispositif anti-retour selon un plan C-C, une poulie munie d'un dispositif anti-retour dans une position autorisant le déplacement, le câble étant sensiblement plié par la poulie,
• la figure 12 illustre, de manière schématique, en perspective, un premier mode de réalisation d'une poulie avec un dispositif anti-retour,
• la figure 13 illustre, de manière schématique, en vue de côté une poulie munie d'un dispositif anti-retour selon la figure 12,
• les figures 14 et 15 illustrent, de manière schématique, en vue de dessus et en coupe dans le dispositif anti-retour selon le plan C-C, une poulie dont le dispositif anti-retour est dans une position de circulation ou dans une position de blocage.

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 represented in the appended drawings, in which:

• there figure 1 illustrates, schematically, in perspective, a first embodiment of a pulley with an anti-return device;
• there figure 2 illustrates, schematically, in perspective, a second embodiment of a pulley with an anti-return device;
• there Figure 3 illustrates, schematically, a pulley with an exploded view of the anti-return device;
• there Figure 4 illustrates, schematically, in sectional view along plane AA at the level of the anti-return device;
• there Figure 5 illustrates, schematically, in side view a pulley equipped with an anti-return device;
• there Figure 6 represents, schematically, in top view and in section in the anti-return device along the plane BB, a pulley whose anti-return device is in a circulation position;
• there Figure 7 represents, schematically, in top view and in section in the anti-return device along the plane BB, a pulley whose anti-return device is in a blocking position,
• there figure 8 represents, schematically, in front view, a pulley whose anti-return device is in a position allowing movement, the cable being substantially rectilinear,
• there Figure 9 illustrates, schematically, in side view and in section in the anti-return device along a plane CC, a pulley provided with an anti-return device in a position allowing movement, the cable being substantially rectilinear;
• there Figure 10 represents, schematically, in front view, a pulley whose anti-return device is in a position allowing movement with the cable bent by the pulley,
• there Figure 11 illustrates, schematically, in side view and in section in the anti-return device along a CC plane, a pulley provided with an anti-return device in a position allowing movement, the cable being substantially bent by the pulley,
• there Figure 12 illustrates, schematically, in perspective, a first embodiment of a pulley with an anti-return device,
• there figure 13 illustrates, schematically, in side view a pulley provided with an anti-return device according to the Figure 12 ,
• THE figures 14 and 15 illustrate, schematically, in top view and in section in the anti-return device according to the plane CC, a pulley whose anti-return device is in a circulation position or in a blocking position.

Description of embodiments

As illustrated on the figures 1 to 7 , a pulley device 1 comprises a pair of sheaves 2 or rollers which are advantageously of identical structures. The pair of sheaves 2 are mounted in line. The two sheaves 2 have a groove so that the in-line assembly of the two grooves defines an axis of circulation of a cable 3 in the pulley. The circulation axis of cable 3 corresponds to or is parallel to the longitudinal axis of cable 3.

Each sheave 2 is rotatably mounted on a shaft 4, preferably freely rotating. The two shafts 4 are fixed on a support bracket 5. The support bracket 5 is advantageously in the shape of an inverted U. The support bracket 5 may be a metal support bracket. The support bracket 5 can be formed by a sheet metal deformed to define a U or substantially a U. The support bracket 5 can be produced by an assembly of several elements and for example first and second flanges. The support bracket 5 defines first and second wings 6 and 7.

Such a device is advantageously used for the aerial transport of a person during a zip line passage on a rope or an insurance cable (not shown). Pulley 1 circulates along cable 3 which is fixed.

The two sheaves 2 are mounted movable in rotation by means of two rotation shafts 4. The two rotation shafts 4 are installed parallel to each other. The two rotation shafts 4 define two different axes of rotation. The two axes of rotation advantageously belong to the same plane which divides each sheave into two equal parts.

In a particular embodiment, the stirrup 5 has two opposite wings 6 and 7. The two shafts 4 are advantageously fixedly mounted on the two wings 6 and 7.

Pulley 1 can be made in different shapes. In the configuration illustrated in figure 1 , the first wing 6 extends under the sheaves 2. The first wing 6 is associated with a movable finger 8 which cooperates with the second wing 7 to close a housing of the cable 3 in the pulley 1. The movable finger 8 has a button actuation 9 which is used to unlock the movable finger 8 and move it to an open position. In the open position, the movable finger 8 is moved away from the second wing 7 in order to be able to insert or extract the cable 3 there.

In the configuration illustrated in figure 2 , the support stirrup 6 defines two through holes which allow the passage of a carabiner 10. The carabiner 10 is installed between the two sheaves 2. The opening of the movable finger of the carabiner 10 allows it to be inserted or removed. extract the cable 3. The carabiner 10 passes through the support bracket 5 which defines the mechanical connection between the carabiner 10 and the cable 3. The carabiner 10 is mounted in the through hole to define the mechanical connection between the the user and the cable 3. When the user is suspended by means of the carabiner 10, the carabiner 10 presses on the support stirrup 5 which is held by the cable 3.

In all the illustrated embodiments, the pulley 1 defines a housing for inserting the cable 3, other configurations are possible. The pulley 1 circulates along the longitudinal axis of the cable 3, bearing on the two sheaves 2, inside the grooves.

The pulley 1 includes an anti-return device 11 which is configured to allow the movement of the pulley 1 relative to the cable 3 in only one direction. The anti-return device 11 authorizes the movement of the pulley 1 relative to the cable 3 along the longitudinal axis of the cable 3 in a first direction called the forward direction. The anti-return device 11 prevents the movement of the pulley 1 relative to the cable 3 in a second direction opposite to the first direction and called the rear direction.

The anti-return device 11 is advantageously fixed to the support bracket 5. Advantageously, the anti-return device 11 is fixed removable relative to the support bracket 5.

As illustrated in figures 3 to 7 , the anti-return device 11 comprises a blocker 12 which defines a groove 13. The blocker 12 has first and second side walls 12a and 12b which are connected to each other by a bottom wall so as to define the groove 13. Groove 13 cooperates with cable 3 to ensure blocking of the pulley in the rear direction without hindering forward progression. Cable 3 circulates inside groove 13.

The blocker 12 is mounted movable between a first position called the circulation position and a second position called the blocking position. In the circulation position, the blocker 12 authorizes movement between the cable 3 and the pulley 1 in the first direction. In the blocking position, the blocker 12 presses on the cable 3 which prevents the movement of the pulley 1 in the second direction. In the blocking position, the blocker 12 presses on the two opposite walls of the cable. The blocker is placed in a buttress position in order to block the cable in the pulley.

Between the first position and the second position, the blocker 12 moves angularly. The movement of the blocker 12 can be a pure rotation, but it can also be a mixture between a rotation and a translation or a more complex movement with a rotation. From the first position to the second position, at least the first side wall 12a of the blocker 12 moves along the axis of circulation of the cable 3 to follow the movement of the cable 3, that is to say along the second sense. It is possible that the two side walls can move, but it is advantageous for the movement of the second side wall 12b to be as reduced as possible to ensure good compactness of the anti-return device 11.

Between the first position and the second position, the value of the displacement of the first side wall 12a is different from the value of the displacement of the second side wall 12b along the axis of circulation of the cable 3. In other words, the first and second side walls 12a and 12b move over different distances along the axis of circulation of the cable 3 because of the rotation of the blocker 12. The rotation of the blocker 12 causes an offset of the side walls 12a and 12b along the axis of circulation of the cable 3. In other words, the two contact zones between the cable 3 and the side walls 12a and 12b belong to two distinct planes perpendicular to the longitudinal axis of the cable.

Between the first position and the second position, the orientation of the blocker 12 changes. The orientation of the blocker 12 can be represented by the value of the angle which exists between the longitudinal axis of the cable 3 and the axis which connects the two side walls 12a and 12b. Preferably, the value of the angle changes continuously in absolute value.

It is advantageous to provide that the blocker 12 does not have a rotation shaft which connects the blocker to the support stirrup or to the rest of the pulley.

As the blocker 12 turns, the distance accessible to the cable 3 to pass inside the groove 13 decreases, the friction increases until the moment when the blocker 12 comes to rest on the cable 3 and immobilizes the double pulley 1.

When the pulley 1 moves in the first direction, the cable 3 rubs on one or other of the side walls of the blocker 12 which causes the movement of the blocker 12 towards the first position or its maintenance in the first position which is a position allowing movement. In the illustrated embodiment, when the pulley 1 moves in the first direction, the cable pushes the blocker 12 towards a stop in a configuration where the opening defined by the groove 13 is maximum. When the pulley 1 moves in the second direction, because of friction, the cable 3 applies a force on the blocker 12 to move it towards the second position. The first side wall 12a moves in the second direction. The two side walls move until the second side wall comes to a stop and is blocked. The first side wall 12a continues to move because of the cable 3 which causes the blocker 12 to rotate. The blocker 12 rotates until the second side wall 12b comes into contact with the cable 3 simultaneously with the contact between the cable 3 and the first wall 12a. The opposite sides of the cable 3 rest on the first and second side walls so that the cable 3 is held fixed relative to the cable. The first side wall comes to rest on the stop, which blocks the blocker 12 and blocks the pulley 1 on the cable 3. The blocker 12 can no longer rotate, which blocks the movement of the pulley relative to the cable 3.

The rotation of the groove 13 takes place around an axis which passes through the cable 3, that is to say which is located between the two side walls of the groove 13. The value of the angle of rotation to obtain the blocking of the cable is defined by the diameter of the cable and the width of the groove. Thus, a blocker 12 is able to block several cable diameters. However, to increase the reactivity of the blocker 12 and/or to ensure its compactness (that is to say limit the angular range to obtain the blocking of the thinnest cable), it is advantageous to use grooves adapted to cable ranges 3. To increase the versatility of the pulley, it is advantageous to form a first groove with a first width at one end and to form a second groove with a second width at the other end of the blocker. To adapt to the diameter of the cable, simply turn the blocker 12 over to move from one groove to another.

Advantageously, in the circulation position, the two side walls of the groove 13 do not come into contact simultaneously with the cable 3, which greatly reduces the friction caused by the pulley in its movement in the first direction. The width of the groove 13 is slightly greater than the diameter of the cable 3.

The pulley 1 is intended to cooperate with a cable of diameter D. The diameter is advantageously between 12mm and 13mm. Conventionally, adventure parks are equipped with 12mm, 12.7mm and/or 13mm cables. In an advantageous embodiment, the distance which separates the two side walls of the groove 13 is greater than the diameter D over a distance at least equal to half the diameter and preferably less than twice the diameter. In this way, the blocker 12 comes into contact with the cable 3 on the two diametrically opposite sides in the blocking position. This configuration makes it possible to have a particularly effective blocker 12 and in particular more effective than a groove configuration 13 which is more restricted.

It is particularly advantageous to provide that the groove 13 is configured so that the bottom wall comes into contact with the cable 13 in the first position, in the second position and between these two positions. It is preferable that the blocker 12 is mounted movable perpendicular to the plane containing the axes of rotation of the sheaves 2 and that the side walls extend along an axis perpendicular to the plane containing the axes of rotation of the sheaves 2.

As illustrated in figures 4 and 5 , it is advantageous for the blocker to be mounted free of movement in a direction perpendicular to the axis of circulation of the cable and perpendicular to an axis which connects the two lateral faces which allows during circulation of the pulley in the first direction of circulation to have a movable blocker to reduce the friction forces linked to the blocker 12 in the first direction of circulation. As illustrated in figures 8 , 9 , 10 And 11 , the freedom of movement of the blocker 12 relative to the cable makes it possible to maintain a blocking position independently of the deformation of the cable linked to the pulley. THE figures 9 And 11 show the vertical displacement of the blocker imposed by the deformation of the cable. The blocker remains in a position allowing movement and the movement of the blocker does not modify the engagement of the blocking position, unlike the prior art.

As illustrated in figures 4 and 5 , it is also advantageous for the blocker to be mounted free of movement in a plane perpendicular to the axis of circulation of the cable in the direction connecting the lateral faces which allows when circulation of the pulley in the first direction of circulation to have a movable blocker to reduce the friction forces linked to the blocker 12 in the first direction of circulation.

Advantageously, the anti-return device 11 defines a housing 14 which contains the blocker 12. The blocker 12 is movably mounted in the housing 14. The blocker 12 defines stops which limit the movement of the blocker 12 in the first position and in the second position. The position of the stops defines the value of the angular displacement of the blocker 12 between the first and second positions.

In the illustrated embodiment, the housing 14 is configured to define a functional clearance with the blocker 12. The functional clearance allows movement of the blocker 12 perpendicular to the axis of circulation of the cable 3 and advantageously parallel to the axis of rotation sheaves 2. The functional clearance makes it possible to adapt the position of the groove 13 in relation to the position of the cable 3 and in relation to the housing. The functional clearance makes it possible to limit the friction between the blocker 12 and the cable 3 when the pulley 1 moves in the forward direction while ensuring continuous or quasi-continuous contact between the blocker 12 and the cable 3.

It is also advantageous to provide that another functional clearance exists between the cable 3 and the blocker 12 in a direction parallel to the axis of rotation of the blocker 12 and in a plane perpendicular to the longitudinal axis of the cable 3. The clearance functional allows free movement of the blocker above the cable 3 when moving the pulley. The weight of the blocker 12 presses the blocker 12 on the cable 3 which ensures continuous or quasi-continuous contact between the blocker 12 and the cable 3. The weight of the blocker 12 ensures sufficient friction with the cable 3 to detect the direction of movement of the cable 3 and modify the position of the blocker 12 accordingly. The functional clearance allows a translation of the blocker perpendicular to the axis of circulation of the cable 3 and advantageously perpendicular to the plane containing the axes of rotation of the sheaves 2.

During its movement, the position of the cable in the pulley changes according to the movements of the user, the two functional games ensure continuous or quasi-continuous contact between the cable 3 and the blocker 12 without introducing significant friction.

In a particular embodiment, the blocker 12 is mounted movable around an axis of rotation which is perpendicular to the longitudinal axis of the cable 3 and perpendicular to the axis of rotation of the sheaves 2. The axis of rotation of the blocker 12 is perpendicular to the plane containing the axes of rotation of the two axes of rotation when the sheaves 2 are identical. This embodiment is more effective than the configuration where the groove is rotated by 90° in the plane perpendicular to the axis of circulation of the cable 3 because the weight of the blocker 12 does not generate a force imposing continuous or quasi-continuous contact of the same side wall on cable 3.

When the pulley 1 travels in the forward direction, the blocker 12 rubs on the cable 3 which pushes the blocker 12 against first and second stops 15a, 15b of the side walls of the housing 14 so that the blocker 12 is in the position of circulation. When pulley 1 seeks to move in the rear direction, blocker 12 rubs on cable 3 which pushes blocker 12 against third and fourth stops 15c and 15d. One of the side walls of the blocker 12 moves over a short distance or does not move or hardly at all while the other side wall moves over a much longer distance to achieve the angular movement of the blocker 12.

The housing 14 defines first and third stops 15a and 15c which limit the movement of the first side wall 12a of the blocker 12 along the axis of circulation of the cable 3. The stops 15a and 15c are separated by the first side wall 12a. The second and fourth stops 15b and 15d limit the movement of the second side wall 12b of the blocker 12 along the axis of circulation of the cable 3. The stops 15b and 15d are separated by the second side wall 12b.

The distance between the second and fourth stops 15b and 15d is less than the distance between the first and third stops 15a and 15c along the axis of circulation of the cable 3. Advantageously, the distance between the second and fourth stops 15b and 15d defines a small functional clearance so that the blocker 12 can move along the axis of circulation of the cable 3 for example by 1mm or 2mm.

In an advantageous configuration, the housing 14 is mounted fixed relative to the stirrup 5 when the blocker 12 moves between the first position and the second position. This configuration ensures better operation of the blocker. For example, the housing 14 is fixed to the bracket 5 by means of a screw 15.

Preferably, the housing 14 is configured to prevent the rotation of the blocker 12 perpendicular to the axis of circulation of the cable 3 and parallel to the axis of rotation of the sheaves 2. In the illustrated configuration, the housing 14 is mounted removable relative to the support bracket 5. This makes it possible to form a double pulley which can be provided with or without the anti-return system 11.

The blocker 12 is advantageously formed by a metal plate, for example a steel plate which defines the groove 13. The blocker can be in the form of a flat plate.

The housing 14 is advantageously closed by a cover 16.

In the illustrated embodiments, the blocker 12 is formed by two parallel opposite faces and the housing 14 defines a support plane perpendicular to the axis of circulation of the cable 3. When moving the pulley in the first direction of movement , the cable pushes the blocker against the support surface. Other forms of blockers are possible in cooperation with a support plane which deviates from a perpendicular position to obtain the first position and the second position.

The configuration illustrated does not have a spring pushing or pulling on the blocker in order to gain compactness. However, it is possible to provide the use of a spring which is configured to push or pull on the blocker 12 in order to place it in the second position in the absence of stress. When the pulley is requested to move in the first direction of movement, the cable 3 forces the spring and modifies the angular opening of the groove. This embodiment is less advantageous than the previous one because the spring causes the blocker 12 to continuously rub on the cable.

THE figures 12 , 13, 14 and 15 illustrate a particular embodiment of a pulley mentioned above. The pulley has a blocker 12 mounted to rotate and preferably only mounted to rotate. In the illustrated embodiment, the axis of rotation is defined by a rotation shaft 17 mounted at one end of the blocker 12. The housing 14 defines a cavity cooperating with the shaft 17 to define the rotation of the blocker 12 perpendicular to the longitudinal axis of the cable and preferably perpendicular or almost perpendicular to the axis of rotation of the rollers 2.

There Figure 14 illustrates the forward movement of the pulley relative to cable 3. The direction of movement is represented by the arrow. There Figure 15 illustrates the reverse circulation of the pulley relative to the cable 3. The desired direction of circulation is represented by the arrow.

When the pulley travels forward, the cable pushes the blocker against the housing so that the opening in the blocker 12 is greater than or equal to the diameter of the cable 3. The pulley can move along the cable with friction weak induced by the blocker 12. On the contrary, when the pulley tries to move in the other direction, the friction between the cable and the blocker pushes the blocker to move away from the end side wall of the housing. The blocker 12 turns which reduces the effective width of the groove 13. The more the blocker 12 turns, the more the width decreases which increases the friction until the blocker blocks the pulley on the cable. As with the previous configurations, the blocker can define two different groove widths 13 to adapt to at least two different diameters of cable 3. It is advantageous for the housing to define a cavity having a substantially circular section to receive a rotation shaft having a substantially circular section.

As with the previous embodiments, the housing 14 can define first and second stops 15a, 15b which fix the position of the blocker in the position authorizing movement in front of the pulley. It is also possible that the case defines a third fog 15c and a fourth stop 15d. However, it is preferable that the cavity defines a circular arc extending over more than half of the circle to hold the rotation shaft in the cavity when the cable pulls on the rotation shaft to cause rotation of the blocker 12 . THE figures 14 and 15 represent a cavity forming at least ¾ of a circle and which maintains the rotation shaft of the blocker in the cavity.

As indicated above, this embodiment makes it possible to have a blocker which moves in rotation around the axis of rotation defined by the cavity and the rotation shaft. This also allows the translational movement of the blocker along the longitudinal axis of the cavity and the blocker.

Claims (15)

1. Pulley (1) designed to move along a longitudinal axis of a cable (3) of a first diameter comprising :

   - a pair of sheaves (2) arranged in line, the pair of sheaves (2) having grooves defining an axis of circulation of the cable (3) in the pulley (1) and corresponding to the longitudinal axis of the cable (3),

   - a blocker (12) movable between a first position allowing displacement of the pulley (1) along the longitudinal axis of the cable (3) in a first direction and a second position preventing displacement of the pulley (1) in a opposite second direction, the blocker (12) defining a groove (13) designed to cooperate with the cable (3), the groove (13) comprising first and second opposite side walls (12a, 12b) connected by a bottom wall, the blocker (12) being arranged so that the axis of circulation of the cable (3) passes between the two side walls (12a, 12b),

   pulley (1) characterized in that at least the first side wall (12a) is movable along the axis of circulation of the cable (3) and in that the displacement of the blocker (12) between the first position and the second position corresponds to a displacement of the first side wall (12a) in the second direction to shift the first and second side walls (12a, 12b) along the axis of circulation of the cable (3) and block the pulley (1) on the cable (3) by overcentring.
2. Pulley (1) according to claim 1 wherein the blocker (12) is mounted freely in a direction perpendicular to the axis of circulation of the cable (3) and perpendicular to the axes of rotation of the sheaves (2), the weight of the blocker (12) driving one of the side walls (12a, 12b) of the groove (13) or the bottom wall towards the axis of circulation of the cable (3).
3. Pulley (1) according to claim 2 wherein the blocker (12) is arranged so that the weight of the blocker (12) brings the bottom wall and the axis of circulation of the cable (3) closer together.
4. Pulley (1) according to one of the preceding claims, wherein the first and second side walls (12a, 12b) are mounted so as to be movable along the axis of circulation of the cable (3), when the blocker (12) moves from the first position to the second position, the distance of movement of the first side wall (12a) is greater than the distance of movement of the second distance along the axis of circulation of the cable (3).
5. Pulley (1) according to one of the preceding claims configured to cooperate with a cable (3) of a first diameter and wherein the separation distance between the first and second side walls (12a, 12b) is greater than the first diameter at least over a height greater than half the first diameter so that the first and second side walls (12a, 12b) are separated by a diameter of the cable (3) in the first position and in the second position.
6. Pulley (1) according to one of the preceding claims, comprising a housing (14) housing the blocker (12), the housing (14) defining stops (15a, 15b) limiting the displacement of the first side wall (12a) and the second side wall (12b) along the axis of circulation of the cable (3) in the first direction.
7. Pulley (1) according to the preceding claim wherein the housing (14) and the blocker (12) define a functional clearance in a direction passing through the two side walls (12a, 12b) of the groove (13) and the axis of circulation of the cable (3).
8. Pulley (1) according to one of claims 6 and 7 wherein the housing (14) and the blocker (12) define a functional clearance in a direction passing through the bottom wall and the axis of circulation of the cable (3).
9. Pulley (1) according to any one of claims 6 to 8, wherein the blocker (12) is removably mounted with respect to the housing (14).
10. Pulley (1) according to any one of claims 6 to 9, wherein the housing (14) prevents rotation of the blocker (12) about an axis of rotation parallel to the axes of rotation of the sheaves (2).
11. Pulley (1) according to any one of claims 6 to 10, wherein the housing (14) is mounted stationary relative to a support bracket (5) supporting the sheaves (2) when the blocker (12) moves between the first and second positions.
12. Pulley (1) according to any one of claims 6 to 11, wherein the housing (14) is removably mounted relative to a support bracket (5) supporting the sheaves (2).
13. Pulley (1) according to any one of claims 6 to 12, wherein the housing (14) defines first and third stops (15a, 15c) limiting the displacement of the first side wall (12a) of the blocker (12) along the axis of circulation of the cable (3) and second and fourth stops (15b, 15d) limiting the displacement of the second side wall (12b) of the blocker (12) along the axis of circulation of the cable (3), the distance between the second and fourth stops (15b, 15d) being less than the distance between the first and third stops (15a, 15c) along the axis of circulation of the cable (3).
14. Pulley (1) according to any one of claims 6 to 13, wherein the housing (14) defines first and second stops (15a, 15b) configured to form a bearing plane for the blocker (12) in the first position perpendicular to the axis of circulation.
15. Pulley (1) according to any one of claims 6 to 11, wherein the housing (14) defines a cavity cooperating with a rotation shaft (17) mounted on the blocker (12), the cavity and the rotation shaft imposing a rotation of the blocker (12) when the blocker (12) blocks the pulley (1) on the cable (3) by overcentring.

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