EP2406447A1

EP2406447A1 - Antitheft device for merchandise including means for the placement and simplified removal thereof

Info

Publication number: EP2406447A1
Application number: EP10715312A
Authority: EP
Inventors: Alain Favier
Original assignee: Exaqtworld SA
Current assignee: Exaqtworld SA
Priority date: 2009-03-09
Filing date: 2010-03-09
Publication date: 2012-01-18
Anticipated expiration: 2030-03-09
Also published as: FR2942835B1; ES2442895T3; EP2406447B1; US20120011904A1; US8733138B2; FR2942835A1; WO2010103228A1

Abstract

The invention relates to an antitheft device (1) to be attached to an item capable of being stolen and including a control portion (2) that is rotatable relative to an attaching portion (3), said attaching portion (3) including an attaching means (4) that is translatably movable with an unlocked position, for placing of the item into the device (1) and for removing same, and wherein the rotation of the control portion (2) relative to the attaching portion (3) translates the attaching means (4), and with a locked position (4) for maintaining the device (1) on the item and wherein the rotation of the control portion (2) relative to the attaching part (3) does not translate the attaching means (4). The control portion (2) comprises a transmission mechanism (15) with a controller for the torque applied to the control portion so that the locked position is achieved for a predetermined value of the torque of forces.

Description

Anti-theft device with simplified placement and removal

The present invention relates to an antitheft device for clinging to an article that may be stolen, and an antitheft system associated therewith.

Certain types of sensitive products such as glasses, golf clubs, alcohol bottles, shoes, tennis rackets or some fragile textiles such as ties or bristles require effective protection against shoplifting. .

However, the existing macaroons or antitheft markings for the protection of this type of product have often complex opening and closing systems, which can in certain cases irreversibly damage the article for which they were to provide protection, and sometimes require the protection. use of mechanical and / or electronic tools bulky and sometimes tedious operation.

It should be added that these antitheft markings are often large and too heavy compared to the article to be protected. The present invention aims to solve all or part of the disadvantages of the state of the art.

For this purpose, the subject of the invention is an antitheft device intended to hook onto an article that may be stolen, comprising a control part movable in rotation with respect to a fastening part, said fastening part comprising latching means movable in translation with an unlocked position for the introduction of the article into the device and its withdrawal and wherein the rotation of the control portion relative to the attachment portion causes the translation of hooking means, and a locked position for retaining the device on the article and wherein the rotation of the control portion relative to the hooking portion does not cause the translation of the hooking means.

This provision allows a simplified security of the article by free from the use of any material for its implementation.

The locked position is automatically reached for a predetermined value of a force torque applied to the control portion. Thus, the user wishing to lock the device on the article in order to prevent its withdrawal exerts a force couple until reaching a predetermined value which depends on the device itself, in particular the internal transmission system connecting the control part. to the attachment means, and not the user.

This predetermined value once reached leads, by design of the aforementioned internal system, to a predetermined force exerted by the fastening means of the device on the article. It is then no longer possible to transmit additional effort to the attachment means because the internal system temporarily no longer temporarily connects the control part to the attachment means. The internal system connecting the control part to the attachment means comprises, locally in the transmission chain of the forces, a connecting portion which is designed (sizing ...) to stop automatically when the effort applied to it exceeds a threshold value (like a mechanical fuse). If the user continues to apply a force torque to the control part no more effort is transmitted in the transmission chain due to the interrupted link portion.

More particularly, the predetermined value of the force torque to be applied to the control part is defined during the design of the device and, in particular, during the design of the various parts constituting the internal force transmission system connecting the control part. to the attachment means.

The manufactured device thus comprises in itself the adjustment of the control portion to the predetermined value mentioned above. According to one characteristic, the predetermined value is such that the force exerted by the fastening means of the device on the article is adjusted according to the article. The dimensioning performed during the design of the device is adapted to the nature or type of the article to be protected.

For the same type of article, for example glasses, the sizing is the same regardless of the article model. Thus, the predetermined value of the force torque to be applied to the control portion and the resultant force exerted on the article do not vary from model to model.

For example, whatever the model of glasses and in particular the thickness of the branches of the glasses the predetermined value of the couple of forces and the resulting force exerted on the article are the same.

A device is therefore applicable to the same type or to the same type of article. However, for a different type of article, for example a bottle, a pre-set / differently sized device is to be used.

According to one feature, the force exerted on the article is sufficient to avoid manual removal of the device of the article without being too high so as not to damage the article.

This arrangement makes it possible to adjust the device on the article with a pressure adapted to, on the one hand, not to risk damaging it, for example by scratching or crushing it and, on the other hand, to exert a force sufficient pressure on the article so that removal of the device from the article is not easy.

According to one characteristic, the hooking portion comprises a fixed portion against which the hooking means press the article in the locked position.

This arrangement makes it possible to secure fragile articles without having to pierce them, contrary to what certain existing anti-theft devices do.

Thus, the hooking means move in translation to press the article or a part thereof against a fixed portion and exert on it a predetermined clamping pressure or force and adapted to prevent separation of the device. Article. This fixed portion serves as a stop.

For example, the pressure or clamping force is applied in one or more directions on one or more surfaces of the article or part of it and the movement of the latter in a direction perpendicular to the aforementioned direction (s) is thus prevented.

According to one characteristic, the attachment portion comprises a passage opening of the article in which the attachment means move in translation.

This passage opening can be through an axis of introduction in the case of a golf club, glasses, or tennis racket sleeves but can also be non-through to allow the attachment of the device on items that can not be introduced in a through opening, as is the case of textile products for example.

In another aspect, the shape of the opening is adapted to the shape and dimensions of the article on which the device is intended to hang.

This arrangement makes the device more reliable by removing geometric insertion constraints and eliminating the possibility for a thief to force the device by introducing a tool through the opening.

According to one characteristic, the fixed portion is defined by a wall or by one of the walls delimiting the opening.

Thus, if the opening is defined by a ring-shaped support, the fixed portion is defined by the inner surface of the ring. According to one characteristic, the control portion is rotatable about an axis along which the hooking means are translated.

Thus, the effort exerted by the user is a rotational effort. In practice, the user turns an actuating member (eg button or knob) integral with the control part.

According to one characteristic, a system internal to the device transforms the rotational movement into a translation movement.

The design of this transmission system defines the predetermined adjustment values of the torque and the force exerted on the article. According to one characteristic, the control part has a contact surface for the rotation of said control part by a user, the contact surface being located at a distance from the axis of rotation. The distance between the axis of rotation and the contact or actuation surface defines a lever arm which makes it possible to increase the clamping force to exert on the article from a predetermined value of torque of forces to be applied. for use on the control part. This arrangement thus constitutes for the user an aid for locking the device on an article.

A normal effort on the part of the user is sufficient to exert on the article a tightening force which normally would require the use of a tool and require a greater force. According to one characteristic, the device is configured / designed so that the distance between the contact surface and the axis of rotation is such that the force exerted by the attachment means of the device on the article is obtained for a predetermined value. reduced force torque applied to the control part. Note that the actuating or gripping surface (actuating portion) of the control portion of some devices may be sized to be relatively far from the axis of rotation and thereby increase the lever arm effect. The goal here is to reduce as much as possible the effort that the user must produce to lock the device. In other cases, it is preferred to have a device that is as compact as possible and thus avoids giving too large dimensions to the actuating portion of the control portion. This choice is preferred for example when the article is relatively small.

The choice between the one and the other case may depend on the nature of the article to be protected and may also or alternatively fall within an easy compromise of implementation / compactness.

According to one embodiment, the control part comprises a casing integral with an actuating wheel enclosing a rotatable cam intended to drive in translation the catching means, a transmission mechanism intended to create a first mechanical connection between the housing and the cam in a preferred direction of rotation and a clutch mechanism for creating a second mechanical connection between the housing and the cam in both directions of rotation.

According to the same embodiment, the transmission mechanism comprises an S-shaped portion, integral with the cam and whose ends of the branches of the S are elastically deformable in the plane of the S and in the form of saw teeth on their outer contour , and a ring disposed facing the housing and whose inner contour has a sawtooth-shaped shape whose teeth have a shape complementary to those present at the ends of the S-shaped portion and having projecting elements blocking the rotation of the the ring in a direction of rotation by their interaction with elements integral with the housing.

According to the same aspect, the clutch mechanism comprises a finger movable in translation inside a first housing formed in the cam and of complementary shape to that of the contour of the finger, a return spring which in the rest position maintains entirely the movable finger inside the first housing, and a second housing formed on the housing of complementary shape to that of the contour of the finger.

advantageously; identification or identification means, such as RFID, radiofrequency, acoustic or electromagnetic means, are placed in the rotatable control portion. The geometry and shape of the control part can accommodate any type of anti-theft plotter or coil thus making it compatible with all types of technologies in the sector of the industry of electronic antitheft prevention of articles and traceability.

The invention also relates to an anti-theft system comprising an antitheft device as described above and comprising identification means, a means for unlocking the device for moving from the locked position to the unlocked position, and a means for detecting means of identification, such as a security gantry.

The invention will be better understood from the description which follows, with reference to the attached schematic drawings showing, by way of non-limiting examples, some embodiments of an antitheft device according to the invention. Figure 1a is a perspective view of an antitheft device according to a first embodiment of the invention.

Figure 1b is an exploded perspective view from above of the antitheft device shown in Figure 1a. Figure 2a is a perspective view of an antitheft device according to a second embodiment of the invention.

Figure 2b is an exploded perspective view from above of the antitheft device shown in Figure 2a.

FIG. 3a is a perspective view of an anti-theft device in a situation according to a third embodiment of the invention

Figure 3b. is an exploded perspective view from above of the antitheft device illustrated in Figure 3a.

Figure 4 is an exploded perspective view from below of the antitheft device according to a fourth embodiment. According to FIGS. 1a, 2a, 3a, an antitheft device 1 according to the invention comprises a control part 2 and a fastening part 3.

The attachment portion 3 has an opening 6 for the introduction or removal of the article to be protected. As shown in each of these figures, this opening 6 may have several forms according to the article to be secured. The device of FIG. 1a makes it possible to secure pairs of eyeglasses by inserting one of the branches of the pair of spectacles through the opening 6.

The device of Figure 2a allows for example the securing of golf clubs or tennis rackets by inserting their sleeve through the opening 6 or bottlenecks of wine bottles and spirits.

The device of FIG. 3a makes it possible to secure textile articles or fabrics 25 by inserting one of the edges 26 of the fabric 25 through the opening 6. This avoids having to pierce the fabric 25 with a nail, as this is the case in many antitheft devices of the state of the art. As shown in Figures 1b, 2b, 3b or 4 the attachment portion 3 of an antitheft device 1 according to the invention is divided transversely into two half-portions or half-boxes 3a and 3b. These two half-portions 3a and 3b are made integral with each other for example by means of pins 7a arranged transversely projecting along the joint plane on one of the half-portions aligned with holes 7b arranged transversely following the join plane on the other half-portion. This mechanical connection is permanently maintained for example by an ultrasonic welding process.

Other systems for assembling half-portions are conceivable.

These two half-portions 3a and 3b contain hooking means 4 which clamp the article to be protected as it passes through the opening 6,

These attachment means 4 comprise a fixed part 4a constituted by a wall formed by the union of the two half-portions 3a and 3b, and a translational part 4b. The translational part 4b comprises a cylindrical portion 10b hollow and threaded on its inside and a flat portion 4b 'of rectangular shape located in a plane transversely intersecting the cylindrical portion 10b and having a length and a width greater than the diameter of the cylindrical portion 10b.

The flat portion 4b 'protrudes into the opening 6 in which it is retained by a surface resulting from the meeting of the two half-portions 3a and 3b serving as a rear stop for the flat portion 4b'.

The fixed part 4a and the movable part 4b with its flat portion 4b 'are opposite each other in the opening 6. The fixed part 4a may also serve as a front stop for the flat portion 4b' in the case where no article has passed through the opening 6.

Rubber pieces 5 are glued on the facing surfaces of the fixed portion 4a and the flat portion 4b 'of the movable portion 4b to provide more adhesion to the antitheft device 1 once it is locked on the article but also in order to preserve the article and the anti-theft device 1 itself when tightened on the article.

As shown in FIGS. 1b, 2b, 3b, the control part 2 of an antitheft device 1 according to the invention comprises among other things a cam 9 and an actuating wheel 21 providing the mechanical connections with the hooking portion 3. In fact, by joining the two half-portions 3a, 3b of the hooking portion 3 form a first annular groove 11a inner and a second external annular groove 8a. The cam 9 of substantially cylindrical shape, has a disk-shaped annular portion 11b and a threaded portion 10a. The annular portion 11b is intended to move in, the first annular groove 11a of the hooking portion 3 while the threaded portion is introduced into the hollow cylindrical portion 10b and threaded of the movable portion 4b of the attachment means 4 This annular portion 11b is introduced into the annular groove 11a inner at the time of the meeting of the two half-portions 3a, 3b.

It is understood here that a cam is a mechanical part transforming a rotary movement into a translational movement. A holding piece 8b comprising a circular portion having a lip 8c of diameter substantially equal to that of the inside of the outer annular groove 8a is forcefully introduced on the same groove 8a on the attachment portion 3. The holding piece 8b is thus retained on the attachment portion 3, also preventing the separation of the two half-portions 3a, 3b.

The cam 9 has on its upper part a coaxial housing 12a for accommodating in its entirety a finger 13.

The finger 13 is metallic and has on one of its two ends a projecting element 13a allowing it to be disposed coaxially to a through hole of the cam 9 formed along its axis of rotation. On the other end of the finger 13 is a rectangular portion 13b in which is formed a housing 14a for receiving a helical compression spring 14. Once the antitheft device 1 mounted, the spring 14 is at rest or compressed between the housing 14a formed in the rectangular portion 13b of the finger 13 and another housing 14b formed on the housing 18 (on an inner face) of the control portion 2.

Coaxially with this housing 14b, it is provided on an inner face housing 18 another housing 12b of complementary shape to the rectangular shape of the rectangular portion 13b of the finger 13.

The assembly comprising the finger 13, the housing 12a on the cam 9, the housing 14a on the finger 13 the spring 14 and the housing 14b and 12b on the housing 18 constitutes a clutch mechanism 24 for the antitheft device 1.

Coaxially with this clutch mechanism 24, a transmission mechanism 15 with a torque controller is arranged in the control part 2 of the antitheft device 1.

This mechanism 15 comprises a portion 16 of the S-shaped cam 9 formed thereon integrally, and a ring 17 disposed between the cam 9 and the housing 18.

The two ends 16a of the S-shaped portion 16 are flexible along the S plane and each provided with a sawtooth portion 19a. The plane of S is, in the examples described, perpendicular to the axis of rotation of the cam.

The ring 17 has, on its inner contour 19b, a sawtooth shape whose teeth have a shape complementary to those of the portions 19a, and on its underside of the projecting elements 20a, for example, in the form of rectangular trapezoids arranged on flexible branches transversely to the plane of the ring 17. This configuration is illustrated in Figures 2b and 3b but the projecting elements 20a may have another shape and be arranged on the outer contour of the ring 17 as shown in FIG. figure 4.

A housing 18a formed on the inner face of the housing 18 allows the coaxial movement of the ring 17 with the partial 6 of the cam 9 in the shape of S.

This movement is stopped in a direction of rotation by projecting elements 20b, also of trapezoidal rectangle shape, formed on the housing 18 on the trajectory of the rectangular trapezoidal protruding elements 20a arranged on the flexible branches of the ring 17.

The trapezoidal rectangular elements of the housing 18 and the crown 17 are arranged in opposition so that the slopes of two trapezoids rectangles meet in a direction of rotation, thus allowing the branches of the crown 17 to flex and the crown to rotate, while in the other direction of rotation, the rectangular sides of the trapezoids meet, thus preventing bending of the branches of the ring 17 and therefore the rotation thereof.

Alternatively, it will be noted that other elements attached to the ring 17, on the one hand, and to the casing 18 (internal face), on the other hand, can fulfill the same functions of meshing in a direction of rotation (the crown and the housing being rotatably connected) and rotated relative to each other in the opposite direction.

Finally, identification or marking means 23 are concealed inside the control part 2. These means may comprise an antenna as illustrated in FIGS. 2b and 2c or be electromagnetic as illustrated in FIG. 1b. In this last example, it is shown that the actuating wheel 21 can take another form to adapt to the identification or identification means 23 used.

This wheel 21 is closed on its rear part by the casing 18. As illustrated in FIGS. 2b, 3b and 4, the wheel 21 comprises complementary projecting portions 22a and recesses 22b disposed on the casing 18. This mechanical connection and therefore access to the interior of the control part 2 is rendered tamper-proof for example by an ultrasonic welding process.

Streaks 21a are formed on the contour of the wheel 21, (surface contact or actuation) to facilitate the grip by the user.

It is also possible to add to the wheel 21 a display device (not shown) having a display area larger than that of the wheel 21 and for viewing additional information on the article protected by the anti-theft device 1 according to the invention. Regarding the use of the device 1 according to the invention, during the establishment of the device 1 on an article to be protected, the user begins by spreading the attachment means 4 to the maximum to allow insertion of the article in the opening 6. In other words the attachment means are moved so that they penetrate as little as possible inside the opening and thus clear the free space in the opening. opening for the passage of a portion of the article therein. For this, it turns the knob 21 according to its opening direction, this movement rotates the ring 17 in its blocking direction. At the same time, the inner contour 19b of the crown 17, despite the non-locking position of the sawtooth moments of the inner contour 19b of the ring 17 and of the S-shaped piece 16 disposed on the cam 9, still leads to the latter. This movement is possible because in the absence of a force exerted on the moving part 4b of the attachment means 4, the flexibility of the branches of the S-shaped piece 16 disposed on the cam 9 is sufficient to allow the driving of the cam 9 and thus the translation of the mobile part 4b of the attachment means 4.

Once the article passed through the opening 6, the user will turn the knob 21 in the closing direction of the attachment means 4 which will initially cause the ring 17 whose teeth contour 19b interior will block the teeth of the S-shaped piece 16 disposed on the cam 9, then drive the cam 9 in rotation which, in turn, causes the mobile part 4b of the attachment means 4 in translation until that she reaches the article.

Once the movable portion of the hooking means in contact with the article and for a predetermined torque value during the design of the device (torque of clamping forces applied by the user on the wheel), the ring 17 will enter in rotation in its direction of rotation, as opposed to blocking direction, thus making unnecessary any further tightening attempts.

Note that the predetermined value of the force torque is given in the examples described by the force to be applied by the user during tightening to disengage the elements protruding from the ring of complementary projecting elements of the housing. The diameter of the actuating wheel centered on the axis of rotation of the cam facilitates the clamping force to be applied by the user to exercise on the article a much higher clamping force.

When the predetermined value of the torque of forces is reached by the user pressing the knob of the control part, the attachment means exert on the article a predetermined clamping force by the design of the device and which is adapted to the article. This clamping force is determined by sizing of all the constituents of the internal motion transmission system which has just been described.

The article is thus locked with the antitheft device and therefore secure. The locating means 23 hidden in the control part 2 of the antitheft device 1 according to the invention will trigger an alarm when passing the article near a security portal.

Once secured, loosening of the anti-theft device 1 of the article will not be possible because, in the loosening direction of the knob 21, the flexibility of the branches of the S-shaped part 16 disposed on the cam 9 is too important to oppose the torque exerted during tightening. The branches of the S-shaped piece 16 disposed on the cam 9 will thus flex primarily radially, that is to say in the plane of the S, without any movement being transmitted to the attachment means 4.

The only way to release the article of the antitheft device 1 according to the invention is to engage the wheel 21 with the cam 9 by means of the clutch mechanism 24.

For this, the user must have a powerful neodymium-type magnet against the outer face of the housing 18 to release the metal finger 13 from its housing 12a and attract against the inner face of the housing 18 by opposing the compression force of the spring 14.

At the same time, the user must turn the knob 21 in the direction causing the hooking means 4 to open. For a certain position of the knob 21, the rectangular portion 13b of the metal finger 13 will enter the housing 12b of complementary rectangular shape of the housing 18. The rotation of the wheel 21 will then directly cause the rotation of the cam 9 by means of the finger 13, the rectangular portion 13b will be disposed partly in the housing 12a of the cam 9 and partly in housing 12b of casing 18.

Once the antitheft device 1 separated from the article, the user moves the magnet away and the spring 14 relaxes, causing the finger 13 inside its housing 12a in the cam 9. The device 1 is thus ready to a new use.

As goes without saying, the invention is not limited to the embodiments of this device 1, described above as examples, but it encompasses all variants. The finger 13 may for example have any shape except circular, the housing 12a and 12b to have a shape capable of rotating the finger 13.

It will also be noted, in a non-limiting manner, that the control part may be of a different shape with one or more gripping members of different shapes and dimensions.

In addition, the internal system for transmitting the rotational movement produced by the user and transforming into a movement of axial displacement of the hooking means may be different.

The constituent elements of this system and interconnected must be able to transmit a force to move the attachment means to a certain value of effort from which the connection between two of the elements cooperating together is interrupted.

For example, it may be a disengagement or uncoupling of two parts from each other when the applied force torque exceeds a predetermined value applied during manufacture.

For example, the force exerted by a user on the device of Figures 2a and 2b is 22.05 N, the radius of the wheel 21 is 1.27 cm and the force torque produced is 28 Ncm. The resulting clamping force that is applied by the device to the article is about 200 N.

The force exerted by a user on the device of FIGS.

1b, to give rise to the same torque force of 28 Ncm and produce the same clamping force of 200 N, is reduced compared to that indicated above due to the larger lever arm. Indeed, the wheel 21 comprises two portions which extend from the central casing 18 in directions opposed to increase the distance between the actuating surface offered to the user and the axis of rotation shown in Figure 1 b. The actuating wheel has for example a general shape of hammer head which facilitates gripping. The distance between a free end of one of the two portions and the axis is for example 2.35 cm which requires the user to develop a force of only 11, 92N.

Claims

1. Anti-theft device (1) for hooking onto an article that can be stolen, comprising a control part (2) rotatable with respect to a hooking part (3), said hooking part ( 3) comprising hooking means (4) mobile in translation with:

an unlocked position intended for the introduction of the article into the device (1) and its removal and in which the rotation of the control part (2) with respect to the attachment part (3) causes the translation fastening means (4), and

a locked position intended to retain the device (1) on the article and in which the rotation of the control part (2) with respect to the attachment part (3) does not cause the translation of the means of latching (4), characterized in that the locked position is reached for a predetermined value of a force torque applied to the control portion (2).

2. Antitheft device according to claim 1, characterized in that the value is predetermined during the design of the device.

3. antitheft device according to claim 1 or 2, characterized in that the predetermined value is such that the force exerted by the fastening means of the device on the article is adjusted according to the article.

4. Antitheft device according to claim 3, characterized in that the force exerted on the article is sufficient to prevent manual removal of the device of the article without being too high so as not to damage the article.

5. antitheft device according to one of the preceding claims, characterized in that the attachment portion (3) comprises a fixed portion against which the hooking means press the article in the locked position.

6. antitheft device (1) according to one of the preceding claims characterized in that the attachment portion (3) comprises an opening (6) for the passage of the article wherein the attachment means (4) move in translation.

7. Antitheft device (1) according to claim 6 characterized in that the shape of the opening (6) is adapted to the shape and dimensions of the article on which it is intended to hang.

8. antitheft device according to claim 5 and claim 6 or 7, characterized in that the fixed portion is defined by a wall defining the opening.

9. anti-theft device according to one of the preceding claims, characterized in that the control portion (2) is rotatable about an axis along which the hooking means (4) are translated.

10. Anti-theft device according to claim 9, characterized in that a system internal to the device transforms the rotational movement into a translational movement.

Anti-theft device according to claim 9 or 10, characterized in that the control part (2) has a contact surface for the rotation of said control part by a user, the contact surface being situated at a distance from the 'rotation axis.

12. antitheft device according to claim 11, characterized in that it is configured so that the distance between the contact surface and the axis of rotation is such that the force exerted by the fastening means of the device on the article is obtained for a predetermined reduced value of the force torque applied to the control part.

13. Antitheft device (1) according to one of the preceding claims characterized in that the control portion (2) comprises a casing (18) integral with an actuating wheel (21) enclosing:

- A cam (9) rotatable for driving in translation the hooking means (4),

- a transmission mechanism (15) with a torque controller for creating a first mechanical connection between the housing (18) and the cam (9) in a preferred direction of rotation, and

- A clutch mechanism (24) for creating a second mechanical connection between the housing (18) and the cam (9) in both directions of rotation.

14. Antitheft device (1) according to claim 13 characterized in that that the transmission mechanism (15) with torque controller comprises:

- a portion (16) S-shaped, integral with the cam (9) and whose ends (16a) of the branches of S are elastically deformable in the plane of the S and have a sawtooth shape on their outer contour, a ring gear (17) arranged facing the casing (18) and whose inner contour (19b) has a sawtooth shape whose teeth have a shape complementary to those present at the ends (16a) of the part (16); ) S-shaped and having elements (20a) protruding blocking the rotation of the ring (17) in a direction of rotation by their interaction with elements (20b) integral with the housing (18).

15. Antitheft device (1) according to one of claims 13 or 14 characterized in that the clutch mechanism (24) comprises:

- a finger (13) movable in translation inside a first housing (12a) formed in the cam (9) and of complementary shape to that of the contour of the finger (13),

- a return spring (14) which in the rest position fully maintains the finger (13) movable within the first housing (12a), and

- A second housing (12b) formed on the housing (18) of complementary shape to that of the contour of the finger (13).

16. Antitheft device (1) according to one of the preceding claims wherein means (23) for identification or marking, such as RFID, radiofrequency, acoustomagnetic or electromagnetic means, are placed in the control part (2) movable in rotation.

An anti-theft system comprising: - an antitheft device (1) according to claim 16,

- unlocking means for moving from the locked position to the unlocked position, and

means for detecting the identification means according to claim 16, such as a security gantry.