EP2893106B1 - Shock-resistant motorized locking device - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to the field of electrical devices to provide a locking function, such as motorized locks or mechatronic positioning sets, comprising an electric actuating element and a pivoting lever for locking the device.

The present invention relates more particularly to the holding of high security locks, having a high resistance to mechanical shocks assenées during an external attack of the device. The invention also relates to a mechatronic system to withstand an external shock or a high frequency vibration, as may be subject to actuators embedded in automobiles or aircraft in an accident.

STATE OF THE PRIOR ART

We know in the state of the art the French patent FR2945065 describing an electronic lock comprising a stator and a rotor rotatably mounted in the stator and a rotor locking member movable between a locking position in which it engages the rotor to block its rotation and a retracted position in which it releases the rotation of the rotor. A movable stop movable between a first position in which it opposes a displacement of the locking member from its locking position and a second position in which the locking member is free to leave its locking position. The movable stop includes a permanently magnetized portion adapted to retain the movable stop in its first position, bearing against a fixed stop without consuming energy when shaking is applied to the lock.

The European patent EP2412901 discloses another example of an electronic lock, comprising a stator and a rotor, a rotor locking member and a lever movable between a locking position, and unlocking. An arm memory is rotated between a rest position and storage under the action of a magnet. This arm comes into contact with a mechanical stop.

The patent US5010750B1 also discloses an electronic lock, comprising a stator and a rotor, a rotor locking member and a lever movable in rotation between a locking and unlocking position. This lock further comprises an actuator for moving the lever between its locking and unlocking positions.

DISADVANTAGE OF THE PRIOR ART.

In the solutions of electronic locks of the prior art, the locking member is in contact, at rest and in the locking position, with a mechanical stop against which it relies. Therefore, by applying violent or periodic shocks, at a given frequency, it can cause the unblocking of this unexpected body. Shock vibrations applied to the frame are transmitted by the stop to the movable member, and the transmitted energy causes the displacement of this member and the undesired release of the lock.

The skilled person is therefore confronted with a paradoxical situation where it is necessary to ensure the mechanical locking of a locking member by preventing any mechanical contact capable of ensuring mechanical energy transmission.

SUMMARY OF THE INVENTION

The invention relates, in its most general sense, to a locking device comprising a movable locking member, the displacement of which can be prevented by a locking member interacting with a motorized lever, characterized in that said motorized lever is rotatable about a axis relative to the frame, the center of gravity of said lever being located on said axis, said lever being maintained in a determined stable position and without rigid mechanical contact of the lever with the frame out of its axis of rotation. The mechanical wave propagating in a structure during an impact is transferred to the locking lever by the mechanical contact points that it has with the fixed frame. Thus, the shock wave is propagated by the pivot axis on the one hand and by the capture device (at the above-mentioned point of contact) on the other hand. If, due to the balancing of the lever, the device is insensitive to what is transmitted by the axis, it is however sensitive to the force transmitted to the capture device. This is similar to what happens in a Newton's pendulum when the end ball is ejected because of the kinetic energy transmitted to it by the dropped ball.

Thus, regardless of the capture force generated between the rotary lever and the frame, there will always be a risk of propagation of a shock of sufficient intensity to eject the lever from its stability position and thus unlock the lock.

The invention thus proposes a locking device comprising an electric actuator displacing, within a frame, a locking lever in rotation about a fixed axis relative to the frame, said lever having its center of gravity on said fixed axis characterized in that said lever is maintained in a determined stable position and, at rest, without rigid mechanical contact of the lever with the frame out of its axis of rotation.

The term "at rest" in the sense of this patent means the state of the device when it is locked and no effort is exerted on any of its components.

The notion of rigid mechanical contact is generally implemented when the lever is in mechanical contact with a rigid part integral with the frame. This rigid connection then transmits the energy of the shock to the lever when the frame is struck.

On the contrary, the invention eliminates this rigid connection between frame and lever to make the lever insensitive to any external shock because the impact energy is never transmitted elsewhere than the center of gravity of the lever, which does not generates no torque and maintains a position.

Advantageously the stable position is achieved without power consumption.

Various embodiments of this function have been devised. The suspension without rigid contact of the lever can thus be obtained by elastic elements (at least one mechanical spring) or preferably by magnetic elements (connection without contact magnet / magnet or magnet / ferromagnetic material). This suspension can be independent, or integrated with the actuating means of the locking lever.

These suspension means without rigid contact create a mechanical filter type "low-pass" which excludes transmission of shocks and vibrations at high frequency (relative to the resonant frequency of the device).

In a particular embodiment, the actuator moving the locking lever also realizes the magnetic force maintaining the stable position of the lever.

The invention also aims at providing an actuator for a locking device driving in rotation about a fixed axis a locking lever characterized in that the locking lever has its center of gravity on said fixed axis and in that the actuator comprises at least one magnet and has a variable gap to ensure a stable position without power consumption.

Advantageously, the gap is minimum when the lever is in its locked stability position and maximum in the unlocked position.

BRIEF DESCRIPTION OF THE FIGURES

• La figure 1 est une représentation en perspective d'un dispositif complet de serrure électromécanique basé sur l'emploi d'un moteur électrique et d'un dispositif stabilisateur sans contact selon un premier mode de réalisation.
• Les figures 2a, 2b et 2c sont des vues de face en détail du dispositif de la figure 1, représenté dans trois états différents.
• La figure 3 est une représentation de l'invention selon un deuxième mode de réalisation du dispositif d'actionnement, qui présente intrinsèquement une caractéristique de stabilité sans courant réalisée par l'actionneur.
• Les figures 4a, 4b et 4c sont des vues de face en détail du dispositif de la figure 3, représenté dans trois états différents.
• La figure 5 est un tracé du couple qui s'exerce sur le levier de verrouillage en fonction de l'alimentation de l'actionneur et de la position du levier selon la réalisation présentée en figure 3.
• La figure 6 est une représentation en perspective d'un dispositif complet de serrure électromécanique dans un exemple qui ne fait pas partie de l'invention basé sur l'emploi d'un actionneur de type solénoïde à palette et d'un stabilisateur à base de ressorts élastiques.
• Les figures 7a, 7b et 7c sont des vues de face de détail selon 3 états de la structure présentée en figure 6.
• Les figures 8a et 8b sont des vues de face de détail selon 2 états d'une variante de la structure présentée en figure 6.

We can better understand the relevance of the invention through the description of the following different figures, with different possible variations:

• The figure 1 is a perspective representation of a complete electromechanical lock device based on the use of an electric motor and a non-contact stabilizer device according to a first embodiment.
• The Figures 2a, 2b and 2c are front views in detail of the device of the figure 1 , represented in three different states.
• The figure 3 is a representation of the invention according to a second embodiment of the actuating device, which intrinsically has a characteristic of stability without current carried by the actuator.
• The Figures 4a, 4b and 4c are front views in detail of the device of the figure 3 , represented in three different states.
• The figure 5 is a plot of the torque that is exerted on the locking lever according to the supply of the actuator and the position of the lever according to the embodiment presented in figure 3 .
• The figure 6 is a perspective view of a complete electromechanical lock device in an example which does not form part of the invention based on the use of a solenoid-type paddle actuator and a spring-elastic stabilizer.
• The Figures 7a, 7b and 7c are front views of detail according to 3 states of the structure presented in figure 6 .
• The Figures 8a and 8b are detailed front views according to 2 states of a variant of the structure presented in figure 6 .

DETAILED DESCRIPTION OF THE EMBODIMENT

The description which follows refers to a nonlimiting example of embodiment in the form of a lock with a movable bolt. But the invention is not limited to the production of a lock and extends to any type of locking device comprising a movable member that can be immobilized transiently via an element interacting with a motorized lever.

The embodiments described in a nonlimiting manner relate to a lock (1) comprising a frame (3), and a bolt (9) movable between translation relative to the frame (3), the displacement of which can be blocked by the engagement head of a piston (6) in a housing (10).

This piston (6) is movable in translation in a direction perpendicular to the direction of movement of the bolt (109). A spring (16) pushes the piston (6) to rest in the direction of the bolt (9), so as to keep the piston head in the engaged position in the housing (10). The piston head (6) has a truncated or conical shape, complementary to the shape of the housing (10), so that the displacement of the bolt (9) pushes the piston (6) due to the transverse component (perpendicular the axis of movement of the bolt (9)) of the forces exerted by the inner edge of the housing (10) on the piston head (6).

The lock further comprises a lever (5) movable between a locking position in which it prevents the displacement of the piston (6), and therefore the release of its head, and an unlocking position where it allows the displacement of the piston and the releasing the bolt (9) when the piston head (6) is completely out of the housing (10).

The object of the invention is to prevent shocks exerted on the bolt (9) or any other accessible part of the lock propagate with sufficient energy to the lever (5) and inadvertently causes its displacement the locking position in another position where it no longer ensures the blocking movement of the piston (6).

The Figures 1, 2a, 2b and 2c represent a motorized locking device (1) in a first embodiment. This lock mechanism comprises a rotary actuator (2), integral with the frame (3), electrically controlled by a polyphase switched motor, a torque motor or a proportional actuator or variable reluctance. The rotor (4) of the actuator (2) is mechanically coupled to the locking lever (5), the design of which allows the latter to disengage the passage of a third part (piston (6) in the drawing) when it has performed its rotational movement generated by the supply of the actuator (2).

This lever (5) has, in association with the rotor (4) of the actuator (2) with which it is connected, a center of gravity on its axis of rotation (7). According to this embodiment, the lever (5) consists of a ferromagnetic material. The lever (5) is thus sensitive to the magnetic field generated by a polarized structure (8) (= magnetized) integral with the frame (3). The magnetic circuit is designed so that it generates a stable position of the lever at least in one position. Thus, in the absence of supply of the actuator (2), the entire rotor (4) undergoes a magnetic attraction, via the lever (5), which tends to reposition it in the vertical stable position. On other mechanisms, one can also imagine having several positions of stability (states locked and unlocked).

From left to right, Figures 2a, 2b and 2c show three states of operation of a locking device employing this first embodiment.

The figure 2a represents the locked state. The bolt (9) is shown in the extended position. A piston (6) of linear stroke is engaged in the bolt (9) in the high position under the action of the spring (16).

It can not go down because of the presence of the lever (5) locking. The engagement of the piston (6) in the bolt (9) is achieved through a housing (10) in the bolt (9). Thus, if a force is applied to the bolt (9), so as to translate it, it is transmitted to the piston (6) in two components. A horizontal component supported by the frame (3) and on the other hand a vertical component, lower, transmitted to the lever (5) locking. The lever being in its vertical stable position, it transmits this force to the frame, due to an elastic deformation of the axis which links it to the motor, or the support of the actuator (2). The piston (6) can not disengage the bolt (9), the lock is locked.

The figure 2b represents the lever (5) when it is rotated by the actuator (2) supplied with electric current. Under the action of the created torque, of greater intensity than the magneto-static torque generated by the polarized structure (8) which tends to keep it in vertical stable position, the lever (5) is pivoted.

The Figure 2c represents the mechanism in the unlocked position. The bolt (9) undergoes an effort that tends to translate it. Due to the respective shapes of the piston (6) and the bolt (9), the piston (6) is driven in translation. Since the lever (5) has been pivoted, the piston (6) can continue its travel until it is completely disengaged from the bolt (9). The lock is then in an unlocked state.

The figures 3 and 4 represent a second embodiment of a mechatronic locking device (1) according to the invention having an operation as described in the explanations of the Figures 1, 2a, 2b and 2c . The The difference is the locking lever (5) which is designed to provide the rotor function to the actuating device as well as the magnetic interaction stability function. Thus, the lever (5) is balanced and polarized by the addition of a magnet (11). A stator (12) fixed to the frame (3) consists of ferromagnetic parts and is provided with a coil (13) generating a magnetic field. When feeding the coil (13), the magnetic field produced is channeled by the ferromagnetic structure of the stator (12). The interaction with the magnetic field created by the magnet (11) of the lever (5) generates a torque between the lever (5) and the stator (11), which induces the rotation of the lever (5). The assembly is designed so that the air gap between the lever (5) and the stator (11) varies as a function of the rotation of the lever (5). It is thus possible to achieve a minimum air gap when the lever (5) is in its stability position and maximum in the unlocked position. In doing so, when the coil (13) is no longer energized, the lever (5) undergoes a torque which tends to keep it in the stable position of minimum air gap.

In figure 4a , the device is shown in the locked position. The piston (6) is engaged in the bolt (9) and its travel is hampered by the vertical position of the locking lever (5). In this position, the air gap between the locking lever (5) and the poles (14) of the stator (12) is minimum. In the absence of power supply in the coil (13), the torque exerted without contact between the lever (5) and the stator (12) is zero in this position. The torque on the lever (5) as a function of its position and the current flowing through the coil (13) surrounding the stator (12) is represented on the figure 5 .

In figure 4b , the lever (5) is rotated during feeding of the coil (13). The air gap is then greater than when the lever (5) is vertical. It follows that if the current is canceled in the coil (13), it will appear a magnetostatic torque (= without current) which will cause the lever (5) to the stable position minimum gap.

Finally, figure 4c the device is shown in an unlocked state. The lever (5) has been rotated from its vertical position, thus releasing the piston (6) which is then likely to descend under the action of a force on the bolt (9).

The figure 5 presents the couples obtained on the axis of the locking lever of an actuator as presented in the descriptions of the figures 3 , 4a, 4b and 4c . The vertical stable position with the minimum air gap corresponds to the 0 ° position. Due to the air gap increase as the lever (5) is rotated, the currentless torque in the coil (13) describes the central solid curve, which is similar to a mechanical stiffness of magnetic origin. The lower - cross - and upper - squares - curves are the pairs obtained for opposite polarity currents in the coil (13). It is therefore possible to go from the locked position 0 ° to the unlocked position -30 ° by applying a current> 0 in the coil (13).

The figure 6 presents an example which does not form part of the invention based on the use of a rotary solenoid type actuator as presented, for example, in the patent FR2834119 . This structure does not include a magnet, it can be doubled to increase the torque on the lever (5). When the coil (13) is energized, the created magnetic flux is channeled by the stator (12), stator (12) which is in two distinct parts, and loops back through the ferromagnetic locking lever (5). In doing so, it appears a force of attraction between the stator (12) and the lever (5). Since the actuator (2) is not polarized, we use here a mechanical spring (15) to ensure the stability of the lever (5) in vertical position. The mechanical spring (15) is advantageously attached to the lever (5) in the vicinity of the axis of rotation, in order to damp the transmission of the shock wave when the lock (1) undergoes an external shock.

The Figures 7a, 7b and 7c present in detail the three distinct states of the solution presented in figure 6 . In figure 7a , the lever (5) is held in a stable position without current by the elastic stiffness of the torsion spring. In figure 7b , feeding the coils (12) generates a torque on the locking lever (5) which pivots by compressing the torsion spring (15). In Figure 7c , the lever (5) has made its entire stroke, under the action of the magnetic field generated by the stator (12). The piston (6) can then slide and release the bolt (9).

The Figures 8a and 8b present another example which is not part of the invention as presented on the figure 6 , with the difference that the mechanical spring (15) employee is of linear type (here tension spring). The Figures 8a and 8b respectively represent the device in the locked and unlocked state.

Claims (9)

1. Locking device comprising:

   - a frame (3);

   - a blocking unit (6);

   - a motorised lever (5);

   - a mobile locking unit (9), the displacement of which can be prevented by the blocking unit interacting with the motorised lever (5) in order to maintain the locking device in a locked state, the said motorised lever (5) being mobile in rotation around an axis (7) relative to the frame (3), between a locking position, in which it prevents the displacement of the blocking unit, in order to maintain the locking device in the locked state, and an unlocking position, in which it permits the displacement of the blocking unit, in the locking position, the lever (5) being in mechanical contact with the frame (3) only by means of its axis of rotation (7); and

   - an actuator (2) which can displace the lever (5) between its locking and unlocking positions,

   characterised in that:

   - the centre of gravity of the said lever (5) is situated on the said axis (7); and

   - the said lever (5) is maintained in a determined stable position corresponding to the locking position, without electrical consumption, by the action of a magnetic force acting without any mechanical contact on the lever (5).
2. Locking device according to Claim 1, characterised in that:

   - the mobile locking unit (9) comprises a receptacle (10);

   - the blocking unit (6) can prevent the displacement of the locking unit (9) by engaging its head in the receptacle (10);

   - in the locking position, the lever (5) can prevent the displacement of the blocking unit (6), and thus the release of the head of the blocking unit (6) from the receptacle (10);

   - in the unlocking position, the lever (5) can permit the displacement of the blocking unit (6) and the release of the locking unit (9) when the head of the blocking unit (6) is completely extracted from the receptacle (10).
3. Locking device according to either of the preceding claims, characterised in that the locking device is a lock.
4. Device according to either of Claims 2 to 3, wherein:

   - the locking unit (9) is a bolt which is mobile in translation relative to the frame (3);

   - the blocking unit (6) is a piston which is mobile in translation in a direction perpendicular to the direction of displacement of the bolt;

   - the locking device comprises a spring (16) which thrusts the piston (6) at rest back in the direction of the bolt (9), such as to maintain the head of the piston in position engaged in the receptacle (10);

   - the head of the piston (6) has a truncated or conical form which is complementary to the form of the receptacle (10), such that the displacement of the bolt (9) thrusts the piston (6) back because of the transverse component, perpendicular to the direction of displacement of the bolt (9), of the forces exerted by an inner edge of the receptacle (10) on the head of the piston (6).
5. Locking device according to any one of the preceding claims, wherein the axis of rotation (7) is fixed.
6. Locking device according to any one of the preceding claims, wherein the actuator (2) can also provide the magnetic force which maintains the said lever (5) in the determined stable position corresponding to the locking position.
7. Locking device according to Claim 6, wherein the actuator (2) comprises at least one magnet (11) and has a variable air gap which makes it possible to ensure the said stable position without electrical consumption.
8. Locking device according to Claim 7, characterised in that the air gap is minimum when the lever (5) is in its locking position, and is maximum in its unlocking position.
9. Device according to Claim 7, wherein:

   - the magnet (11) is secured on the lever (5);

   - the actuator comprises a stator (12) which is secured on the frame (3), this stator (12) being constituted by ferromagnetic parts, and being equipped with a coil (13) which generates a magnetic field, the said ferromagnetic parts being able, when the coil (13) is supplied with power, to channel the magnetic field produced and interact with the magnetic field created by the magnet (11) of the lever (5), such as to generate a torque between the lever (5) and the stator (12), which gives rise to the rotation of the lever (5);

   - the air gap is situated between the lever (5) and the stator (11), and varies according to the rotation of the lever (5), the air gap being minimum when the lever (5) is in its locking position, and maximum in its unlocking position, such that, when the coil (13) is no longer supplied with power, the lever (5) is subjected to a torque which tends to maintain it in the locking position, where the air gap is minimum.

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