EP0869236B1 - Safety cylinder operable from one side even when a key is inserted in the opposite side - Google Patents

Abstract

The cylinder has a stator (1a,b) and rotors (2a,b) with a key recess and a bit (7) between the two rotors (2a,b). The mechanical connection between the bit and at least one of the rotors is effectuated by mechanical connection between the bit and one of the rings of the drive lug. The movement of an axial element (13) is limited so that the axial element does not extend beyond the plane of the central flange (9) of the bit. The movement of the axial element exerts a mechanical pressure on the ring of the other part of the drive lug when acted on by a key which is fully pushed into place.

Description

The invention relates to safety cylinders intended for the control of a lock, said cylinders comprising two barrels of safety which allow a control of the lock on each side of the door on which said lock is arranged.

A double barrel safety cylinder is a device well-known described, for example, in the French patent application 2 686 641. This safety cylinder has two barrels made up each of a stator and a rotor capable of pivoting about an axis relative to the stator, each rotor having a key housing in which protruding keying means, the two stators being formed by coaxial cylindrical shells, which are linked between they according to a generator by a resistant rectilinear beam for form a stator block. Each rotor has, at its opposite end at the key entry, a cylindrical recess on the side wall from which two diametrically opposite slots have been provided. Each of the two barrels is likely to cause, via a mobile coach, a rotary bit carried by the ends of the two rotors, the bit being axially positioned relative to the block stator thanks to mechanical retaining means which are inserted between each of the stators and the bit and which engage in the ends of each of the rotors, so that these retaining means act not only for the axial positioning of the bit relative to the two stators, but also for the axial retention of each rotor in its associated stator.

In a known way, the coach, which allows to join angularly one of the rotors with the bit, is a part carried by the ends of the two rotors and capable of movement axial translation relative to the stator block so as to ensure the mechanical clutch between one or the other of the rotors and the bit, depending on the axial position it occupies. The movement of the coach is carried out under the push of the end of the key when said key is engaged in the key housing of one of the rotors: in this case, the end of the key pushes the coach into a position, where it ensures the clutch between the rotor, where the key is engaged, and the bit; in this position, the other rotor of the stator block is disengaged from the bit.

Generally, the coach consists of two parts having the same profile comprising two diametrically opposite lugs, these two parts being linked together by a common axis and being able rotate freely with respect to each other; the bit has a cylindrical collar in which is formed a median veil, in which there is made an orifice, the outline of which corresponds to the common profile of each of the two parts of the coach. When the coach is in taken with the first rotor and with the bit, the first part of the coach has its pins engaged in the hole in the bit and in slots in the side wall of the end recess of the first rotor; in this position, the second part of the coach has its lugs engaged in the slots in the end recess of the second rotor and thus remains angularly positioned relative to this second rotor.

When the lock is at rest, the angular position of the bit with respect to the stator block and the angular positions of the rotors with respect to said stator block are perfectly defined; in this relative position, the profiles of each part of the coach are vis-à-vis the corresponding holes in the bit wall. When a key is engaged in the first rotor, the coach positions axially so that the profile of its first part penetrates in the opening of the veil of the bit, this first part remaining nevertheless mechanically engaged with the first rotor. This position allows the first rotor to be turned by means of its key associated by training the bit and the first part of the coach, while the second part of the coach is not trained in rotation and remains engaged with the second rotor; due to rotation of the bit, the second part of the coach is no longer in front of the orifice allowing it to be secured to the veil of the bit and the coach can therefore no longer be operated in axial translation by the end of the key associated with the second rotor. It follows that, as soon as a key is inserted into the housing of key of the first rotor and that the first rotor has turned angularly relative to its rest position which allows the extraction of the key, it it is impossible to operate the lock by a key inserted in the key housing of the second rotor, which is still in its rest position: in fact, the key can no longer be fully depressed in its key slot since the second part of the coach comes into abutment against the veil of the bit.

This drawback is particularly serious, if the first rotor was operated by a sick person inside of a room, because it is no longer possible to enter the room in manipulating the lock from the outside to rescue him.

We have already proposed, for example in European patents 291 220, 509 682 and 536 653, coupling mechanisms avoiding the aforementioned drawback by adopting a special structure for the trainer used in the cylinder. Unfortunately, all of these devices have a large number of parts, which generates assembly difficulties, on the one hand, and a price high cost, on the other hand. The present invention therefore aims to offer a coaching structure that is simple and inexpensive for its realization and which leads to an easy assembly, without it being not necessary to modify the realizations previously known barrel rotors and bit associated with cylinders to two barrels.

The present invention therefore relates to a safety cylinder for lock comprising two barrels made up each of a stator and a rotor capable of pivoting about an axis relative to the stator, each rotor having a key housing in which protruding keying means, the key associated with the rotor allowing the declaving of the rotor relative to its stator associated, the two rotors being coaxial and cooperating with a bit single rotary which is arranged between them and can be driven by a coach by one or the other of the two rotors for the operation of the lock, said coach being carried by the bit and consisting of two coaxial parts each associated with one of the two rotors, each part of the coach comprising two elements, namely an element peripheral and an axial element, these two elements being susceptible of a relative translation and being recalled elastically towards the relative position they occupy in the absence of a key. Such a safety cylinder is known from document DE-A-38 28 354. The invention is characterized by the fact that the two parts of the coach are free to rotate one by relative to the other, the peripheral element of a coach part being an annular element of which the axial element of said part is integral in rotation, the trainer being capable of translation along the axis common of the two rotors under the action of at least one key associated with at least one of the rotors to come into a position where it performs a mechanical fastening in rotation between the bit and at least one rotors by mechanical engagement between, on the one hand, the bit and, on the other hand, at least one of the annular elements of the coach.

In a preferred embodiment, each axial element comprises, on the one hand, a cylindrical barrel, which can slide in the corresponding annular element, and, on the other hand, on the rotor side with which it is associated, a front flange on one side of which takes supports an elastic means tending to push it towards its associated rotor and on the other side of which can bear the end of the key of said associated rotor. Advantageously, one of the axial elements is a male element provided, on the side opposite to its flange, of an axial pivot, while the other axial element is a female element rotatably mounted on said pivot and mechanically retained at against the action of the elastic means associated with it; restraint mechanical of the female axial element on its pivot can be obtained by simple crimping.

Advantageously, each annular element comprises a peripheral shell on which two lugs protrude, said peripheral shell sliding in the orifice of the bit, and a internal shell guiding the translation of the associated axial element, the annular space between the two shells serving as housing for a elastic means.

In a manner known per se, it is possible to provide that the bit has a cylindrical collar, which is carried by both ends of the two rotors and held axially with respect to them, said collar being provided with a median veil where an orifice is made, the profile of which allows the axial passage of one or other of the annular elements for a suitable angular positioning of said annular element; But, in addition, the aforementioned orifice allows the axial passage of one or other of the axial elements whatever its angular orientation.

Advantageously, the stroke of an axial element is limited so that said axial element cannot extend substantially beyond the mean plane of the median of the bit when the element corresponding annular is in abutment against the median veil of said bit.

We can predict that the two annular elements are identical and have two diametrically opposite lugs of different cross section, so that the bit cannot be dragged by an annular element only for an angular relative position unique of said bit relative to said annular element.

Preferably, each rotor has, at its end adjacent to the bit, an open cylindrical recess, on the one hand, on its entire face opposite the bit and, on the other hand, in two slots in its side wall, at least one of the two pins of each annular element extending radially so as to be able to engage in a slot in its associated rotor to ensure the connection in rotation between said rotor and said annular element, the axial dimension of the cylindrical recess being sufficient to contain one of the two parts of the coach and avoid, as well, that the annular element of the part contained in the recess does not come into engagement with the bit.

In known manner, the bit can be maintained by compared to the two rotors thanks to two circlips arranged in grooves peripherals of the rotors, on either side of the collar of the bit. We may provide that the elastic means interposed between the collar of a axial element and the corresponding annular element either a spring helical arranged around the axial element.

To better understand the object of the invention, we will describe it now, as a purely illustrative example and not limiting, an embodiment shown in the accompanying drawing.

• la figure 1 représente, en élévation, un cylindre de sûreté selon l'invention, la représentation étant faite avec arrachement pour que la zone centrale du cylindre apparaisse en coupe axiale ;
• la figure 2 représente une vue axiale du panneton du cylindre de la figure 1 ;
• la figure 3 représente, en perspective, le panneton de la figure 2 ;
• la figure 4 représente, en coupe axiale, l'entraíneur du cylindre selon l'invention, dont l'élément axial mâle a été représenté non coupé, sauf pour la partie sertie de son pivot ;
• la figure 5 représente une vue axiale, selon VIII-VIII de la figure 4, de l'élément annulaire de l'entraíneur de la figure 4 ;
• la figure 5a représente une vue axiale de l'élément annulaire de la figure 5, du côté opposé à la vue de la figure 5 ;
• la figure 5b représente une coupe selon Vb-Vb de la figure 5 ;
• la figure 5c représente une vue en perspective de l'élément annulaire de la figure 5, du côté qui est vu sur ladite figure 5 ;
• la figure 5d représente une vue en perspective de l'élément annulaire de la figure 5, du côté opposé à celui vu sur la figure 5c ;
• la figure 6 représente une vue axiale, selon VIII-VIII de la figure 4, de l'élément axial mâle de l'entraíneur de la figure 4 ;
• la figure 6a représente une vue axiale de l'élément axial mâle de la figure 6, du côté opposé à la vue de la figure 6 ;
• la figure 6b représente une vue latérale, selon VIb-VIb de la figure 6, de l'élément axial mâle de ladite figure 6 ;
• la figure 6c représente une vue en perspective de l'élément axial mâle de la figure 6, du côté qui est vu sur ladite figure 6 ;
• la figure 6d représente une vue en perspective de l'élément axial mâle de la figure 6, du côté opposé à celui vu sur la figure 6c ;
• la figure 7 représente une vue, selon VIII-VIII de la figure 4, de l'élément axial femelle de l'entraíneur de la figure 4 ;
• les figures 7a à 7d sont des vues de l'élément axial femelle de la figure 7 analogues respectivement aux vues des figures 6a à 6d de l'élément axial mâle ;
• la figure 8 représente une vue selon VIII-VIII de l'entraíneur de la figure 4 ;
• la figure 9 représente une vue en perspective de l'un quelconque des deux rotors du cylindre de la figure 1 ;
• la figure 10 représente, en coupe axiale, la zone du cylindre de la figure 1 où se trouve le panneton, l'entraíneur de la figure 4 étant mis en place entre les deux rotors du cylindre et une clef étant insérée dans le logement de clef du rotor figuré à droite sur le dessin, la coupe étant faite dans le plan de la clef ;
• la figure 11 représente les mêmes éléments que la figure 10 lorsque la clef du rotor de droite a tourné d'un angle inférieur à 360° et que l'on a introduit une clef dans le logement de clef du rotor de gauche, la coupe étant faite dans le plan de cette dernière clef ;
• la figure 12 représente les mêmes éléments que la figure 11, lorsque la clef du rotor de gauche a tourné pour venir dans le plan où se trouvait la clef du rotor de droite de la figure 11, la coupe étant faite dans le plan commun des deux clefs.

On this drawing :

• FIG. 1 represents, in elevation, a safety cylinder according to the invention, the representation being made with cutaway so that the central zone of the cylinder appears in axial section;
• 2 shows an axial view of the bit of the cylinder of Figure 1;
• Figure 3 shows, in perspective, the bit of Figure 2;
• FIG. 4 shows, in axial section, the drive of the cylinder according to the invention, the male axial element of which has been shown uncut, except for the part set with its pivot;
• 5 shows an axial view, along VIII-VIII of Figure 4, of the annular element of the coach of Figure 4;
• FIG. 5a represents an axial view of the annular element of FIG. 5, from the side opposite to the view of FIG. 5;
• Figure 5b shows a section along Vb-Vb in Figure 5;
• FIG. 5c represents a perspective view of the annular element of FIG. 5, from the side which is seen in said FIG. 5;
• FIG. 5d represents a perspective view of the annular element of FIG. 5, on the side opposite to that seen in FIG. 5c;
• 6 shows an axial view, along VIII-VIII of Figure 4, of the male axial element of the coach of Figure 4;
• FIG. 6a represents an axial view of the male axial element of FIG. 6, from the side opposite to the view of FIG. 6;
• FIG. 6b represents a side view, along VIb-VIb of FIG. 6, of the male axial element of said FIG. 6;
• FIG. 6c represents a perspective view of the male axial element of FIG. 6, from the side which is seen in said FIG. 6;
• FIG. 6d represents a perspective view of the male axial element of FIG. 6, on the side opposite to that seen in FIG. 6c;
• 7 shows a view, along VIII-VIII of Figure 4, of the female axial element of the coach of Figure 4;
• Figures 7a to 7d are views of the female axial member of Figure 7 respectively analogous to the views of Figures 6a to 6d of the male axial member;
• Figure 8 shows a view along VIII-VIII of the coach of Figure 4;
• Figure 9 shows a perspective view of any of the two rotors of the cylinder of Figure 1;
• 10 shows, in axial section, the cylinder area of Figure 1 where the bit is located, the trainer of Figure 4 being placed between the two rotors of the cylinder and a key being inserted in the key housing the rotor shown on the right in the drawing, the cut being made in the plane of the key;
• FIG. 11 represents the same elements as FIG. 10 when the key of the right rotor has turned by an angle less than 360 ° and when a key has been inserted into the key housing of the left rotor, the cross section being made in the plan of this last key;
• FIG. 12 represents the same elements as FIG. 11, when the key of the left rotor has turned to come into the plane where the key of the right rotor of FIG. 11 was, the cut being made in the common plane of the two keys.

Referring to the drawing, it can be seen that the two stators of the stator block 1 of a safety cylinder comprising two barrels have been designated by 1 a and 1 b . In general, the safety cylinder, which is described here, has identical elements for its right part and its left part in the drawing: the index a is assigned to the references of the organs of the left part and the index b for the references of the organs on the right, the reference figures adopted being the same for the same organs. The stator block 1 constitutes a longitudinal beam in the median axial plane of which the keying devices 200 are arranged, which make it possible to immobilize angularly a rotor 2 a , 2 b placed in each of the stators 1 a , 1 b respectively. Each rotor comprises, in a known manner, a key housing, the teeth of the key ensuring the unlocking of the aforementioned locking means. Each rotor has, at its end disposed in the central zone of the safety cylinder, a recess 3 a , 3 b respectively; the recess 3 a , 3 b is cylindrical and it opens on the outside, on the one hand, by its end face facing the other rotor and, on the other hand, by two longitudinal slots 4 a , 4 b respectively, diametrically opposite.

Each rotor 2, 2b comprises externally in the bottom region of its recess, a peripheral groove 5a, 5b to the bottom of which opens the slits 4 a, 4 b. A circlip 6 a , 6 b is inserted into the groove 5 a , 5 b and comes to block each rotor longitudinally inside its associated stator. Between the two circlips 6 a , 6 b is disposed the bit 7 of the safety cylinder.

Conventionally, the bit 7 comprises a cylindrical collar 8, which is carried by the two ends of the rotors 2 a , 2 b , said collar being provided with a median web 9. The bit 7 also comprises, arranged radially by compared to the collar 8, an operating tab 10, which cooperates with the organs of the lock with which the safety cylinder is associated. The veil 9 has in its central zone an orifice 11 consisting of a circular part 110 to which two diametrically opposite radial parts 111, 112 are connected; the radial parts 111, 112 have different profiles. The collar 8 has an axially length corresponding to that which separates the two circlips 6 a , 6 b , from which it follows that the bit 7 is perfectly positioned longitudinally relative to the stator block 1 and to the two rotors 2 a , 2 b .

The driver 12 of the cylinder of FIG. 1 is made up of two parts, each formed by an axial element 13 a , 13 b and an annular element 14 a , 14 b . The two annular elements 14 a , 14 b are strictly identical with respect to each other, while there is a slight difference between the two axial elements 13 a , 13 b . Indeed, one 13 has axial elements is a female element while the other 13 b is a male element, which comprises a pivot 15. The pivot 15 is mechanically integral with the axial element 13 b and it passes through a axial bore 116 of the axial element 13 a . The two axial elements 13 a , 13 b are capable of moving in a bore 16 a , 16 b of each annular element 14 a , 14 b . Axial elements 13, 13b externally comprise a cylindrical central zone 113 surmounted on two opposite sectors, one of 90 ° and the other of 60 °, two longitudinal thickenings 114, 115 parallel to the axis of the zone 113. Zone 113 and the two extra thicknesses 114, 115 constitute a cylindrical barrel. Each axial element 13 a , 13 b comprises a front flange 17 a , 17 b respectively, which projects radially beyond the longitudinal thickenings 114, 115; each flange 17 a , 17 b therefore consists of two angular sectors, one of 90 ° and the other of 60 °. A helical spring 18 a , 18 b is interposed between the flange 17 a , 17 b and the corresponding annular element 14 a , 14 b , so that the axial elements 13 a , 13 b are pushed by the helical springs 18 a , 18 b identical in the direction which separates the flanges 17 a , 17 b from the median plane of the coach 12. The two axial elements 13 a , 13 b are nevertheless held relative to each other due to the fact that the end of the pivot 15 is crimped to prevent the ejection of the female axial element 13 a under the action of the spring 18 a . For the two axial elements 13 a , 13 b , the axial lengths of the parts 113, 114, 115 are identical; similarly the flanges 17 a , 17 b are identical. In the absence of external action, the two axial elements 13 a , 13 b are therefore arranged symmetrically relative to the median plane of the coach, as shown in FIG. 4.

Each of the annular elements 14 a, 14 b has a cylindrical peripheral shell 214 from which project two pins 215, 216. The lug 216 extends over the entire axial length of the shell 214 while the pin 215 is that a small axial length and is located at the end of one of the shell 214. The profiles of the lugs 215, 216 are different; the two lugs 215, 216 occupy on the shell 214 equal and diametrically opposite angular sectors. On the angular sector occupied by the lug 215, the shell 214 is hollowed out to form a wide slot 221. In line with the lug 215, an internal cylindrical shell 217 is connected coaxially to the shell 214. The shell 217 has two zones recesses 218, 219 allowing the passage of the two extra thicknesses 114, 115 and, over a shorter axial length, the passage of the two sectors of the flanges 17 a , 17 b . The inside diameter of the shell 217 corresponds, apart from the clearance, to the outside diameter of the cylindrical zone 113 of the axial elements 13 a , 13 b . Between the shells 214 and 217 is formed an annular zone, which is extended, in the direction of the bearing end of the lug 215, by a groove 220. The spring 18 a , 18 b is housed in said annular zone and its first turn is arranged in the groove 220. The lugs 215 and 216 have a profile, which corresponds respectively to the radial parts 111, 112 of the orifice 11, and the diameter of the circular part 110 of the orifice 11 is equal, to the clearance close to the outside diameter of the cylindrical shell 214.

It therefore appears that the two annular elements 14 a, 14 b are pressed against each other by the springs 18 a, 18 b which rest on the flanges 17 a, 17 b. The median veil 9 of the bit 7 has a thickness which is sufficient so that, if the support plane of the annular elements against each other is in the median plane of the veil 9, the two pins 215, 216 of the two annular elements each have at least part of their axial length inside the thickness of the web 9, so that, in this position, represented in FIG. 12, the two annular elements 14 a , 14 b are engaged with bit 7.

We will now describe the operation of the safety cylinder shown in the drawing. In this operation, the keys associated with the rotors 2 a , 2 b have been respectively designated by the references 20 a , 20 b . For the remainder of the explanation, it will be assumed that the rotor 2b is disposed on the interior side of the door.

When the key 20 b is introduced into the rotor 2 b , as shown in FIG. 10, the end of the key 20 b comes to bear against the flange 17 b inside the recess 3 b , which pushes the entire driver 12 to the left in Figure 10 and causes the end of the annular element 14 b which carries the lug 215 inside the hole 11 provided for this purpose in the central web 9 of the blade 7 so that the annular element 14 b is engaged with the bit 7; in addition, the lug 216 remains inside one of the slots 4 b of the rotor 2 b , where it follows that the rotor 2 b can rotate the annular element 14 b and, therefore, the bit 7; such a rotation is possible since the key 20 b could come, thanks to the displacement of the annular element 14 b , in its position of maximum insertion allowing the unclogging of the rotor 2 b . Simultaneously, the lugs 215 and 216 of the ring member 14a were positioned within the veil and 9 are fully engaged within the slots 4a of the rotor 2a, so that rotation of the bit 7 can be carried out without any modification of the angular position of the annular element 14a, which remains in place while the pivot 15 is pivoted with the annular elements 14 b and 13 b axially. The operation of the safety cylinder was thus carried out from one of the barrels, without the position of the rotor 2 a of the other barrel having been modified, that is to say that the rotor 2 a is located in the position where the introduction of the key is possible.

FIG. 11 represents the same members as FIG. 10 after the key 20 b has subjected the bit 7 to a rotation of an angle of 90 ° clockwise. If the key 20 a is then introduced into the rotor 2 a , the tip of the key 20 a will be able to penetrate fully into the recess 3 a by engaging in the slot 221 of the annular element 14 a and pushing back the flange 17 a with complete crushing of the spring 18 a . The axial element 13 a mechanically pushes the annular element 14 b to partially release the housings 110 and 111 from the web 9; this thrust from one element to the other is necessary to allow, in all cases, the penetration of the element 14 a into the web 9 under the thrust of the spring 18 a . In fact, if the key which is in the rotor 2b exerts a slight torque, for example due to the fact that it is linked to a set of keys of non-negligible weight, the action of the key causes a slight wedging by friction of the element 14 b in the veil 9 and, in this case, the thrust of the spring 18 a might not be sufficient for the element 14 a to penetrate into the veil 9, because the spring 18 a has low power.

It should be noted that the spring 18 b is partially compressed due to the fact that the key 20 b has necessarily remained in position in the rotor 2 b since, hypothetically, the rotor 2 b has rotated 90 ° and that, consequently , the key 20 b is not in the position where it can be extracted from its key housing. The lugs 215 and 216 of the annular element 14 a are in abutment against the web 9 of the bit 7 and they remain there since the orifices 111, 112 have moved during the rotation of the bit 7. However, if one turns the key 20 a , nothing prevents the rotation of the rotor 2 a and of the annular element 14 a relative to the bit 7, this rotation causing that of the axial element 13 a with pivoting relative to the pivot 15. On can thus bring the key 20 a in the position which corresponds to the position of the key 20 b , in which case the pins 215, 216 come in line with the corresponding radial parts 111, 112 of the orifice 11, which allows the pins 215 , 216 to penetrate inside the orifice 11 while being pushed by the spring 18 a .

This leads to the position shown in FIG. 12, in which the two springs 18 a , 18 b are partially compressed and the two lugs 215, 216 are both engaged in the parts 111, 112 of the web 9 of the bit 7. In this position, any rotation action on the key 20 a will cause the bit 7 and, simultaneously, the annular element 14 b , the rotor 2 b and the key 20 b . This drive can be maintained until one is in the open position of the lock and the two rotors 2 a , 2 b are returned to their rest position which allows the extraction of the key.

We therefore see that it has thus been possible, thanks to the particular structure of the driver 12, the operation of the safety cylinder while the key 20b was engaged in the corresponding barrel and was blocked there by the rotation of the rotor 2 b .

Claims (10)

1. Safety cylinder for a lock comprising two barrels each consisting of a stator (1a, 1b) and a rotor (2a, 2b) capable of pivoting about an axis with respect to the stator (1a, 1b), each rotor (2a, 2b) comprising a key housing, into which keying means project, the key (20a, 20b) associated with the rotor (2a, 2b) allowing the rotor (2a, 2b) to be unkeyed from its associated stator (1a, 1b), the two rotors (2a, 2b) being coaxial and collaborating with a single rotary bit (7) which is positioned between them and can be driven by a driver (12) via one or other of the two rotors (2a, 2b) to operate the lock, the said driver (12) being carried by the bit (7) and consisting of two coaxial parts each associated with one of the two rotors, each part of the driver comprising two elements, namely a peripheral element (14a, 14b) and an axial element (13a, 13b), these two elements being capable of relative translation and being elastically returned to the relative position they occupy in the absence of a key (20a, 20b), the two parts of the driver (12) being free to rotate one with respect to the other, the peripheral element of one part of the driver being an annular element (14a, 14b) to which the axial element (13a, 13b) of the said part is secured so that the two rotate as one, the driver (12) being capable of translation along the common axis of the two rotors (2a, 2b) under the action of at least one key associated with at least one of the rotors so as to come into a position in which it mechanically secures the bit (7) and at least one of the rotors (2a, 2b) so that the two will rotate as one, characterized in that the mechanical securing of the bit (7) and of at least one of the rotors (2a, 2b) so that the two will rotate as one is performed by mechanical engagement between, on the one hand, the bit (7) and, on the other hand, at least one of the annular elements (14a, 14b) of the driver and through the fact that the travel of an axial element (13a, 13b) of one of the parts of the driver (12) is limited so that the said axial element cannot extend beyond the mean plane of the central web (9) of the bit (7), the said travel being nonetheless long enough for this axial element (13a, 13b) to be able to exert mechanical thrust on the annular element (14b, 14a) of the other part of the driver (12) when it is subjected to the action of a key (20a, 20b) fully inserted into the key housing in the rotor (2a, 2b) with which the said axial element (13a, 13b) is associated.
2. Safety cylinder according to Claim 1, characterized in that each axial element (13a, 13b) comprises, on the one hand, a cylindrical shank (113, 114, 115) which can slide in the corresponding annular element (14a, 14b) and, on the other hand, on the same side as the rotor (2a, 2b), a front flange (17a, 17b) against one side of which an elastic means (18a, 18b) tending to push it towards its associated rotor (2a, 2b) bears and against the other side of which the end of the key (20a, 20b) of the said associated rotor (2a, 2b) can bear.
3. Safety cylinder according to Claim 2, characterized in that one (13b) of the axial elements is a male element equipped, on the opposite side to its flange (17b), with an axial pivot (15) whereas the other axial element (13a) is a female element mounted so that it can rotate on the said pivot (15) and held mechanically against the action of the elastic means (18a) associated with it.
4. Safety cylinder according to one of Claims 1 to 3, characterized in that each annular element (14a 14b) comprises a peripheral shell (214) from which two studs (215, 216) project, the said peripheral shell sliding in the orifice (11) of the bit (7), and an inner shell (217) guiding the translation of the associated axial element (13a, 13b), the annular space between the two shells acting as a housing for an elastic means (18a, 18b).
5. Safety cylinder according to one of Claims 1 to 4, characterized in that the bit (7) has a cylindrical collar (8) carried by the ends of the two rotors (2a, 2b) and held axially with respect to them, the said collar (8) being equipped with a central web (9) in which there is made an orifice (11), the profile of which allows the axial passage of one or other of the said annular elements (14a, 14b) for appropriate angular positioning of the said annular element and the axial passage of one or other of the axial elements (13a, 13b) regardless of its angular orientation.
6. Safety cylinder according to Claim 5, characterized in that the central web (9) of the bit (7) is thick enough that, if the plane along which the annular elements bear against each other is in the central plane of the web (9), the two annular elements (14a, 14b) each have at least part of their axial length inside the thickness of the web so that, in this position, the two annular elements are in engagement with the bit (7).
7. Safety cylinder according to one of Claims 1 to 6, characterized in that the two annular elements (14a, 14b) are identical and have two diametrically opposed studs (215, 216) of different cross section so that the bit (7) can be driven by an annular element (14a, 14b) only when the said bit (7) is in one unique relative angular position with respect to the said annular element (14a, 14b).
8. Safety cylinder according to Claim 7, characterized in that each rotor (2a, 2b) comprises, at its end adjacent to the bit (7), a cylindrical counterbore (3a, 3b) open, on the one hand, over its entire face opposite the bit (7) and, on the other hand, via two slits (4a, 4b) in its side wall, at least one of the two studs (215, 216) of each annular element (14a, 14b) extending radially so that it can engage in a slit (4a, 4b) of its associated rotor (2a, 2b) to provide the rotational connection between the said rotor (2a, 2b) and the said annular element (14a, 14b), the axial dimension of the cylinder counterbore (3a, 3b) being large enough to contain one of the two parts of the driver (12) and thus prevent the annular element (14a, 14b) of the part contained in the counterbore (3a, 3b) from engaging with the bit (7).
9. Safety cylinder according to Claim 5 taken alone or in conjunction with one of Claims 6 to 8, characterized in that the bit (7) is held with respect to the two rotors (2a, 2b) by two circlips (6a, 6b) placed in peripheral grooves (5a, 5b) of the rotors (2a, 2b) on each side of the collar (8) of the bit (7).
10. Safety cylinder according to Claim 2 taken alone or in conjunction with one of Claims 3 to 9, characterized in that the elastic means inserted between the flange (17a, 17b) of an axial element (13a, 13b) and the corresponding annular element (14a, 14b) is a coil spring (18a, 18b) positioned around the axial element (13a, 13b).

Images