FR2716484A1 - Burglary detector and preventer for security lock - Google Patents

Abstract

The burglary detector has a stator and rotor cylinder and a mobile bolt. A detector (35) is mounted in the stator and may move axially from an inactive position to an active position. In the active position the detector prevents any latch movement of the bolt. An helicoidal spring (40) is used to push the detector in the active position. Movement of the cylindrical rod (35) is normally constrained by three balls (42,43,44) the first engaging with the throat (41) of the bar. On any attempt to drill the lock the rotor (25) will be pushed backwards and the ball (44) remote from the rod (35) will fall into a channel (46) releasing the rod (35) to prevent latch movement.

Description

 The invention relates to an anti-intrusion device for a security lock of the type comprising a stator cylinder and rotor and a bolt movable under the action of the rotor between a retracted position and a locking position in which the bolt is projecting. .

 In such a lock, axial and / or radial combination elements normally immobilize the rotor in rotation relative to the stator, the introduction of an appropriate key in the cylinder having the effect of aligning these combination elements according to the plane d end and / or the circumferential surface of the rotor and thus allow its free rotation relative to the stator and, consequently, the drive of the bolt by means of a drive mechanism.

 Attempts to break in such a lock generally consist in carrying out an axial drilling resulting in a partial or total destruction of the rotor and / or of the combination elements so as to allow, from the outside, to act directly on the latch drive mechanism. It may also be a forcing aiming, in particular, to break the connection between the rotor and the bolt drive mechanism and to allow the free actuation of this mechanism independently of the rotor.

 In order to protect the security locks against such burglary attempts, it is known to equip them with an indicator device which remains immobilized in an inactive position as long as the lock remains in normal operating condition and which is released. and goes into an active position in which any movement to withdraw the bolt is prohibited in the event of an attempted break-in.

 Patent FR-A-2,500,521 describes such an anti-theft device consisting of a linkage mechanism external to the cylinder, comprising means sensitive to thermal attack by the lock and to displacement of the cylinder.

However, such a mechanism external to the cylinder has a non-negligible size. In addition, its triggering under the effect of a thermal attack is likely to pose reliability problems. Finally, it does not provide sufficient protection in the event of the rotor being pierced.

 It is known from document FR-A-2 626 925 to solve the aforementioned dimensions problems by placing a thermal informer directly in the thickness of the stator.

However, because of its thermal triggering mode, this informer is likely to present reliability problems and risks of untimely triggering.

 Finally, document DE-A-32 26444 describes a device for locking the rotor relative to the stator which is activated in the event of thermal and / or chemical and / or mechanical attack on the cylinder. However, such a device does not offer completely satisfactory protection because, if drilling is continued until the bolt drive mechanism is reached, the latter can then be actuated without hindrance. It is therefore not a reporting device.

 The invention aims to provide a burglar-alarm device for a security lock which is simple and compact in design, which offers high protection against tampering by drilling and / or forcing, and which is particularly functional. reliable.

 To this end, the subject of the invention is an anti-intrusion device for a security lock comprising a stator cylinder and rotor and a movable bolt, said device comprising a feeder mounted in said stator and able to move axially between a position inactive and an active position in which said delator prohibits any movement of the bolt rotor, elastic means for urging said delator in its active position, and means for retaining the delator in its inactive position against said elastic means, characterized in that said retaining means comprise at least one locking element interposed between said delator and a part of said cylinder vulnerable to an attempted break-in by forcing and / or drilling and shaped to allow the displacement of said locking element in the release position of said informant in response to a change in the geometry and / or the position of the ladi you part under the effect of said attempted break-in.

Other characteristics and advantages of the invention will emerge from the following description of embodiments given by way of examples and illustrated by the appended drawings in which
Figure 1 is an axial sectional view of a first type of cylinder equipped with a delator according to a first embodiment of the invention
Figure 2 is a sectional view along line II-II of Figure 1;
Figure 3 is a partial sectional view of a cylinder similar to that of Figure 1 equipped with an informer according to a second embodiment of the invention;
Figure 4 is a view similar to Figure 3 illustrating a third embodiment of the informer according to the invention;
Figure 5 is a view similar to Figure 3 illustrating a fourth embodiment of the informer according to the invention;
Figure 6 is an axial sectional view of a second type of cylinder equipped with a delator according to a fifth embodiment of the invention;
Figure 7 is a sectional view along line VII
VII of figure 6
Figure 8 is an exploded schematic view of a conventional sliding caliper mechanism for actuating a bolt by means of a cylinder according to one of Figures 1 to 7; and
FIG. 9 is an elevation view of the mechanism of FIG. 8.

 Referring to FIG. 1, a security lock comprises a cylinder 1 comprising a cylindrical protective housing 2 in which are housed a stator 3 and a rotor 4.

 The housing 2 has the shape of a skirt, the transverse wall 5 of which has an axial orifice 6 for introducing a key 7 into the rotor 4. Between the stator 3 and the housing 2 is interposed a shield 8 having the form of '' a cylindrical skirt provided with an axial hole for the passage of the key 7. A safety washer 9 fixed relative to the stator 3 and a washer 10 forming a shield for the rotor 4 are interposed between the end face of the rotor 4 facing the orifice 6 and the transverse wall of the shielding 8. The washer 10 is made of a very hard metal alloy, for example a tungsten carbide alloy, and can rotate freely relative to the stator 3, which has the effect to increase the difficulties encountered in the event of an attempt to drill the cylinder 1. The washers 9 and 10 have holes aligned with that of the shield 8 to allow the passage of the key 7.

 The stator 3 consists of an external stator 11 and an internal stator 12 joined together by a strong pin 13 made of a very hard metal alloy, for example a tungsten carbide alloy.

 The combination elements of the cylinder 1 comprise three radial pins 14 slidably mounted in the rotor 4 and which are biased towards the interior thereof by three pushers 15 each subjected to the action of a spring 16. Each pushbutton 15 and its corresponding spring 16 is disposed in a radial bore 17 of the outer stator 11 and, likewise, the pins 14 can slide in bores 18 of the rotor 4 which, in the locking position of the lock, are aligned respectively with the bores 17.

 The cylinder 1 also comprises several axial combination elements, only one of which is shown in FIG. 1. Each axial combination element comprises an axial pin 19 housed in an axial bore 20 formed at the periphery of the rotor 4 from its face end 21 opposite the shielding 10. The internal stator 12 has axial bores 22 in each of which is mounted a pusher 23 biased towards the axial pin 19 by a spring 24. In the locking position of the lock, the bores 20 and 22 are aligned.

 The rotor 4 is secured to one end of a rotor axis 25 by a pin 26 made of a very hard metal alloy, for example a tungsten carbide alloy. The cylindrical rotor axis 25 extends through a cylindrical bore of the inner stator 12 and its end opposite to the rotor 4 has two parallel flats 27 allowing its engagement in a T-shaped slot 28 of rectangular section formed in a room. cylindrical drive 29 rotatably mounted in a ring 30 immobilized between an end face of the external stator 11 and a rear wall 31 closing the cylinder on the side opposite to the wall 5 and having an axial orifice 32 through which protrudes a tubular extension of the ring 30 and part of the drive part 29.

 Finally, the drive part 29 carries an eccentric 33 intended, in a conventional manner, to ensure the displacement in translation of a bolt by means of a sliding caliper mechanism as shown in FIGS. 9 and 10.

 The structure of the cylinder 1 described above as well as its operation are perfectly conventional.

When a key 7 is introduced into the cylinder 1, this has the effect of aligning the end of the pins 14 in contact with the pushers 15 on the cylindrical contact surface of the rotor 4 with the external stator 11. Similarly , each pin 19 is pushed back by the key 7 so that its end face in contact with the corresponding pusher 23 is placed in the joint plane 21.

Thus, the rotor 4 can be freely rotated by the key 7 in the stator 3 and cause the bolt to move through the rotor axis 5 of the drive part 29, of the eccentric 33 and of the sliding caliper mechanism of FIGS. 9 and 10.

 In order to protect the cylinder 1 against attempts to break in by drilling or forcing, it comprises a delator comprising a cylindrical rod 35 having a first part 36 extended by a second part 37 of smaller section than that of the first part 36 The external stator 11 comprises, in an axial plane containing the axis of the pin 13, an axial bore 38 extending between the pin 13 and a second axial bore 39 of larger diameter than the bore 38. The second bore axial 39 extends through the wall 31, the ring 30 and partially in the external stator 11. In the axial bore 39 is housed a helical spring 40 disposed around the part 37 of the rod 35 and bearing against the one of its ends against the bottom of the bore 39 of the external stator 11 and at its other end against the shoulder formed between the parts 36 and 37 of the rod 35. In the vicinity of its end adjacent to the pin 13, l part 37 of the rod 35 has a peripheral groove 41 with a circular profile in which a ball 42 bears. The ball 42 is held at the bottom of the groove 41 by a ball 43 which is itself pushed by a ball 44 which takes bearing against the rotor axis 25. The balls 42, 43 and 44 are freely mounted in a substantially vertical cylindrical radial bore 45 formed in the outer stator 11 and the inner stator 12. Finally, a longitudinal groove 46 is formed in the surface outside of the rotor axis 25, this groove 46 as well as the bores 38, 39 and 45 being centered on the axial plane of the cylinder 1 containing the axis of the pin 13. The groove 46 has a length at least equal to the diameter balls 42, 43 and 44 and it extends longitudinally between bore 45 and pin 26 so that its end situated on the side of bore 45 is placed immediately upstream of the contact zone of ball 44 with the surface ex axis 25.

On the other hand, the depth of the groove 46 is at least equal to that of the groove 41 formed in the rod 35.

 As also shown in FIG. 2, the rotor 4 has several longitudinal pins 47 at its periphery. These pins 47 made of very hard metal alloy, for example tungsten carbide, play no role in the normal operation of the lock and their only function, in the event of an attempted break-in by drilling, is to channel the drilling towards the center of the rotor thanks to their hardness.

 In such a case, the bore is thus channeled towards the radial pin 26 which, by its position, is particularly vulnerable and difficult to protect. If the drilling is continued, the pin 26 is broken and, due to the axial forces applied to the drilling tool, the rotor axis 25 is pushed back to the bottom of the bore 28. During this movement, the groove 46 is moved in line with the bore 45, the ball 44 falls by gravity into the groove 46 and the rod 35 thus released is pushed back by the spring 40 from its retracted and inactive position shown in FIG. 1 in an active position in which it prohibits any movement of withdrawal of the bolt from its locking position.

 The way in which the informer inhibits the operation of the bolt will be better understood by referring to Figures 8 and 9.

 The conventional bolt actuation mechanism shown in these figures comprises a bolt proper 50 comprising a longitudinal slot 51 in which a fixed cylindrical stop 52 protrudes. The bolt has along its lower edge two notches 53 in one or the other of which, depending on the position of the bolt 50, the eccentric 33 of the cylinder 1 can come to engage when the rotor 4 is rotated by the key 7. On the side opposite to the notches 53, the bolt 50 carries a rod 54 extending through the core of a U-section stirrup 55. The rod 54 ends in a head 56, such as a screw, retaining a washer 57. A helical spring 58 is mounted between the washer 57 and the core of the U-shaped stirrup 55. The spring 58 thus urges the stirrup 55 to bear against the bolt 50 as shown in FIG. 9. Each of the sides of the stirrup 55 has a cutout 59 of which the upper edge has three notches 60 defining three s bolt positions 50.

 When the fixed stop 52 is received in one of the notches 60, it prohibits any movement of the stirrup 55, and consequently of the bolt 50 which is integral therewith in translation by means of the rod 54. When the rotor 4 is turned by means of the key 7, the eccentric 33 bears against the lower edge of the flanks of the stirrup 55 and raises the latter until the indentations provided in the upper edge of the cutouts 59 are located at above the stop 52. Continuing the rotational movement of the rotor 4, the eccentric 33 engages in a notch 53 and drives the bolt 50 in translation with the stirrup 55. When, in the pursuit of the rotational movement , the eccentric 33 moves away from the bolt 50, the stirrup 55 descends and comes to a stop in a position in which the fixed stop 52 is engaged in a notch 60 adjacent to that in which this stop 52 was received in the previous position of the bolt. The three notches 60 therefore make it possible to define an open position and two locking positions corresponding respectively to partially and completely projecting positions of the bolt.

 If, in one of the locking positions of the bolt, the informer 35 is triggered as a result of an attempted break-in, the latter protrudes through the cutout 59 of the adjacent side of the stirrup 55. The distance between the rod 35 of the informer and the lower edge of this cutout 59 is chosen such that in the event of displacement upwards of the stirrup 55, the lower edge of this cutout 59 abuts against the rod 35 before the stop 52 has escaped from the notches 60. Under these conditions, any driving of the bolt by the eccentric 33 is prohibited.

 Reference will now be made to FIGS. 3 to 5 which respectively represent three alternative embodiments of the informer fitted to the cylinder 1 and on which the reference numbers of FIGS. 1 and 2 increased respectively by the numbers 100, 200 and 300 have been used to designate the parts. corresponding.

 In the embodiment of Figure 3, the informer differs from that shown in Figure 1 in that the ball 142 is normally held in position at the bottom of the groove 141 of the rod 135 by an L-shaped slide 162 capable of sliding axially with the rotor axis 125 in a cavity 163 formed in the internal stator 112. The slide 162 is engaged in a groove in the rotor axis 125 with which it is thus made integral in translation. The other branch of the L is notched at its upper end so as to provide a cavity 165 in which, in the event of displacement of the slide 162 with the rotor axis 125 under the effect of a drilling, the ball 142 may fall and release the rod 135.

 The embodiment of FIG. 4 differs from that of FIG. 3 only in that the ball 142 is replaced by a cylindrical pin 270 with a spherical head.

 In the embodiment of Figure 5, a wedge-shaped slider 380 is engaged in a groove 381 of the rotor axis 325 so as to be integral in translation thereof. A pusher 382 also in the form of a wedge is pressed against the slide 381 by a radial spring 383. The pusher 382 is slidably mounted in a radial bore 384 of the exterior 311 and interior 312 stators. A plate 385 secured to the pusher 382 and pierced a hole with a diameter at least equal to that of the part 337 of the rod 335 is normally received at the upper part of the periphery of the hole in a groove 386 of the part 337 of the rod 335. The plate 385 and the groove 386 preferably both have a rectangular section.

 If the rotor axis 325 is moved in translation in the direction of the part 329 under the effect of an attempted break-in, the correlative displacement of the slide 380, which is in contact with the pusher 382 by an oblique joint plane , pushes the latter radially upwards against the action of the spring 383. The plate 385, which is integral with the pusher 382, is also moved radially upwards until its central orifice is aligned with the part 337 of the rod 335. The latter is then released and, under the action of the spring 340, it is moved into its active position for immobilizing the bolt in the locked position.

 FIGS. 6 and 7 illustrate an anti-theft tamper device according to the invention applied to a conventional cylinder 401 which differs from the cylinder of FIGS. 1 to 5 in that the stator 403 on the one hand and the rotor 404 on the other hand are each monobloc. The same reference numbers as in FIGS. 1 and 2, increased by the number 400, designate corresponding elements.

 Between the front wall 405 of the cylinder and the stator 403 are interposed an annular crown 471 and a cage 472 in the form of a cylindrical skirt which is itself concentric with an annular extension 473 of the stator 403. The rod 435 of delator extends axially over the major part of the length of the cylinder 401 and its end opposite to the large diameter part 436 ends in a flat 490 received in an annular groove 474 formed internally in the crown 471. The cage 472 has a radial bore 475 in which is housed a ball 442 held engaged in the annular groove 441 of the part 437 of the rod 435 by the annular extension 473 of the stator 403.

 The cylindrical cage 472 is immobilized in rotation relative to the stator 403 in the angular position corresponding to the locking of the rod 435 by the ball 442, by means of a pin 476 with a fracture initiator which is engaged in a radial bore 477 formed in the annular extension 473 and the cylindrical cage 472.

 A pin 478 of large section made of a metal alloy of great hardness, for example tungsten carbide, is housed in the rotor 404, in the axis of the passage of the head of the key 407. This pin 478 serves as a key stop and also prohibits any attempt to break in by drilling with a small diameter drill.

 In the event of an attempt to drill using a large diameter drill in order to destroy the combination elements located upstream of the pin 478 and thus allow the free rotation of the rotor 404 relative to the stator 403, the cylindrical cage 472 automatically finds itself attacked by the drill. Under the effect of the torque which is thus applied to the cylindrical cage 472, the pin 476 with a breaking point is broken and the cage 472 is put into rotation. In its movement, it circumferentially drives the ball 442 which thus escapes from the groove 441 and the informer is released. The rod 435 is pushed back by the spring 440 into its active position where it prohibits any withdrawal of the bolt from its locking position as explained previously with reference to FIGS. 8 and 9.

 As is apparent from the above, the burglar-resistant device according to the invention allows, by purely mechanical means fully integrated into the cylinder and particularly reliable, to irreparably immobilize the bolt in the locked position in the event of attempted break-in by drilling and / or forcing the cylinder.

 It goes without saying that the embodiments described are only examples and they could be modified, in particular by substitution of technical equivalents, without departing from the scope of the invention.

Claims (12)

 1. burglar-resistant device for a security lock comprising a stator cylinder and rotor and a movable bolt, said device comprising a delator mounted in said stator and able to move axially between an inactive position and an active position in which said delator prohibits any movement of withdrawal of the bolt, elastic means for urging said informer towards its active position, and means for retaining said informer in its inactive position against said elastic means, characterized in that said retaining means comprise at least a locking element (42; 142; 242; 385; 442) interposed between said delator (35; 135 235; 335; 435) and a part (25; 125; 225; 325; 472) of said cylinder vulnerable to an attempt to breaking by forcing and / or drilling and shaped to allow the displacement of said locking element in the release position of said informer in response to alteration tion of the geometry and / or the position of said part under the effect of said attempted break-in.  2. Device according to claim 1, characterized in that said part is an axis (25, 125, 225, 325) connecting between the rotor (4) and a part (29; 129; 229 339) for driving the bolt (50).  3. Device according to claim 2, characterized in that said locking element (42; 142; 242; 385) is mounted in said stator (3) so as to move radially between its locking position and said release position in response to an axial displacement of said axis caused by an attempted break-in.  4. Device according to claim 3, characterized in that the radial movement of said locking element (42) is controlled by at least one intermediate piece (43, 44) movable radially in response to said axial movement of said axis.  5. Device according to claim 4, characterized in that said axis (25) comprises a cavity (46) in which said intermediate piece (44) is capable of falling by gravity in response to said axial movement of said axis.  6. Device according to claim 5, characterized in that said intermediate piece and said locking element consist of balls (42, 43, 44) stacked substantially vertically in a radial bore (45) of said stator (3), and the delator (35) comprises a rod having a groove (41) of circular profile complementary to that of said locking ball (42).  7. Device according to claim 3, characterized in that said locking element comprises a pusher (382) in the form of a wedge, bearing against a slide (380) also in the form of a wedge integral in translation with said axis (325), and a plate (385) integral with said pusher (382) and pierced with an opening traversed by said delator (335), said plate (385) being capable of being moved radially outward with said pusher against means elastic (383) from its locked position in which said plate is engaged with a groove from said delator to said release position in which said delator (335) escapes said plate through said opening.  8. Device according to claim 3, characterized in that the radial displacement of said locking element (142; 270) is controlled by a slide (162; 262) integral in axial translation with said axis (125; 225) and arranged to disengage in said stator a cavity in which said locking element is liable to fall by gravity in response to said axial movement of said axis.  9. Device according to claim 8, characterized in that said locking element (142; 270) has at least one spherical part and the delator (135; 235) comprises a rod having a groove (141; 241) of complementary circular profile .  10. Device according to any one of claims 1 to 9, characterized in that said rotor (4) has at its periphery several longitudinal pins (47) of metal alloy of very high hardness suitable, in the event of attempted break-in by drilling, to channel the drilling forces towards the center of the rotor.  11. Device according to claim 1, characterized in that said part is a cylindrical cage (472) coaxial with the stator (403) and normally immobilized in rotation around the latter in a predetermined angular position by connecting means (476), and in that said locking element is a ball (442) normally immobilized by said cage (472) in the wedging position between said stator (403) and said delator (435), said connecting means (476) being arranged to allow the rotation of said cage (472) around the stator (403) and the release of said indicator by said ball in the event of application to said cage of a drilling force.  12. Device according to claim 11, characterized in that said connecting means (476) are of the type with initiation of rupture.