EP0978609A1 - Electric power assisted door lock - Google Patents

Abstract

With the door closed, the bolt-plate (2) notch (9) retains the door-jamb hasp bar (11,13), since the catch (3) prevents the forces opposed by the return spring (14) and compressed peripheral door seal (16) from rotating (F3) the bolt and releasing the door. The catch pivots about an off-centre peg (23) on the face of an eccentric (21), itself rotatable (F5) about a fixed pivot (22) by a geared motor (4,20). To open the door, the motor is run, first aligning the eccentric and catch pivots (27,28) with the catch bearing point (29,8). This slightly increases seal compression and catch pressure, but as the eccentric rotates through a further 180 degrees the catch retreats rapidly from the bearing point (8), allowing the seal and spring forces to assume control of the bolt, whose consequent rotation (F3) liberates the hasp bar. At this point, a radial peg (24) on the eccentric begins to drive the catch directly, clear of the bolt, through a stop (26) on the catch. A manually operated (19) trip lever (17) permits emergency opening during electrical failure. The motor drive, opt., also assists in door closing.

Description

• un pêne pouvant pivoter autour d'un axe et pourvu d'au moins un cran d'arrêt,
• un cliquet pouvant pivoter entre une position de verrouillage ou fermeture, dans laquelle ledit cliquet est en prise avec un cran d'arrêt du pêne, et une position de déverrouillage ou ouverture, dans laquelle ledit cliquet est hors de prise dudit cran d'arrêt, et
• un moteur électrique couplé audit cliquet pour le faire pivoter de sa première position à sa seconde position.

The present invention relates to an electrically assisted door lock, in particular for a motor vehicle, of the type comprising:

• a bolt that can pivot around an axis and provided with at least one stop notch,
• a pawl which can pivot between a locking or closing position, in which said pawl is engaged with a latch stopper, and an unlocking or opening position, in which said pawl is out of engagement with said stopper, and
• an electric motor coupled to said pawl to rotate it from its first position to its second position.

Currently, motor vehicle manufacturers tend to equip vehicle doors with door seals harder and harder to solve comfort problems: impermeability to road noise, airtightness for air conditioners, etc.

Due to the use of harder seals, comfort door opening and closing are considerably decreases. In fact, to close the door, you have to slam it with a more great force to achieve sufficient compression of the door seal for the lock to self-lock. In addition, in the closed state of the door, the door seal exerts on it, by reaction, a force relatively important which is transmitted to the mechanism of the lock. In particular, the bolt and the ratchet of the lock are strongly applied against each other, so the user must exercise relatively large force on the door opening mechanism to be able to release the ratchet from the bolt and thus allow the opening Door.

To overcome these drawbacks, the trend is to equip motor vehicle doors with power assisted locks electric, assistance with opening, but also, in some cases, assistance with closing.

Among the many known assist locks electric, there are some that have two motors, namely a motor for opening and a motor for closing. There are also which have a single motor for opening and closing according to their direction of rotation or according to the angular value of rotation, for example a half-turn for closing and a half-turn additional for opening.

In general, all known locks with assistance electric have motors sized to pass efforts important for opening and even more for closing, which leads to the use of fairly large geared motors, which are expensive and difficult to install in vehicle doors because of the size of the motors and associated reduction mechanisms. In in addition, these geared motors consume energy relatively large and they are often slow and therefore become criticizable in terms of speed, especially when opening (feeling user waiting).

The object of the present invention is therefore to propose a electrically assisted door lock, of the type defined above, which overcomes all these drawbacks.

To this end, the door lock according to the invention is characterized in that the electric motor is coupled to the pawl at means of an eccentric which can be rotated by the motor electric through a shaft whose axis is said to be the first axis of rotation, said axis having a fixed position relative to the axis of the pivot of the bolt, the eccentric bearing a shaft whose axis is said to be second axis of rotation, said second axis being offset from the first axis, the pawl being pivotally mounted on said shaft, a first stop being carried by the eccentric and a second stop being carried by the ratchet, so that, starting from the closed state of the lock, when the eccentric is rotated by the electric motor on a first fraction of a turn, said eccentric moves the pawl by relative to the bolt stop noticeably in a defined direction by a line, which constitutes the trace of the plane defined by the first axis of rotation and the contact edge in a common perpendicular plane P, until the first stop comes into contact with the second stop, after which, when the eccentric continues to rotate on a second fraction of a turn around the first axis of rotation, it drives with it the ratchet by rotating it around the second axis of rotation to release the pawl from the latch stopper.

During the first fraction of a turn of the eccentric, the recoil movement of the pawl relative to the latch stopper has to allow decompression of the seal of the fitted door of the lock according to the invention. By choosing appropriately the eccentricity of the eccentric and / or the angular value of the first fraction of a turn performed by the eccentric, it is possible to do so that the door seal is completely or practically completely decompressed by the time the eccentric has completed said first fraction of a turn. At this time, the reaction exerted by the seal of door on the door is almost zero and, consequently, the force of friction between the bolt and the ratchet, at their point of contact, is greatly reduced compared to that which exists in a lock classic in which the pawl is mounted pivoting about an axis fixed. As a result, the torque that the gearmotor group must produce to overcome this friction force and, therefore, to release the pawl from the latch stopper during the fraction next turn of the eccentric is significantly lower than the one that must be produced by the gearmotor group of a conventional lock. We can show, by calculation, that the torque that the gear motor group associated with the lock according to the invention must produce for open the lock, is about three times weaker than that which must produce the gear motor group associated with a conventional lock, if a friction bearing is used for mounting the eccentric on its axis, and that it can be about ten times weaker if we use a ball or needle bearing for mounting the eccentric on its axis.

In addition, during the entire decompression phase of the joint door, the latter exerts on the door a force which, as we will see in detail below, is transmitted to the bolt of the lock and by this to the ratchet which in turn transmits it to the eccentric in a direction tending to rotate it in the same direction as the direction of rotation produced by the gear motor group. Consequently, during this decompression phase of the door seal, it has a motor action which helps the geared motor group to rotate the eccentric. Thanks to the present invention, it therefore becomes possible to use a less powerful, less powerful motor-reduction unit and consuming less energy than the associated geared motors with classic locks.

For the implementation of the present invention, the value eccentricity of the eccentric can be, for example, chosen from so as to be at least half the difference between the thickness of the door seal in the decompressed state (door open) and the thickness of the door seal in compressed state (door closed). In addition, the first stopper can be arranged in such a way that when it comes in contact with the second stop, at the end of said first fraction of turn, the contact edge between the pawl and the catch is substantially in the plane defined by the first and second axes of rotation, on the side of the first axis where the second axis is not located. Under these conditions, if the said first fraction of a turn corresponds to a angle of about 180 ° or a little more, the eccentric moves the ratchet relative to the stopper by an amount equal to twice the value of the eccentricity and we are then assured that the door seal will be completely decompressed at the end of said first fraction of a turn.

By giving the eccentricity of the eccentric a higher value larger than that indicated above, it is possible to make it so that the door seal is completely decompressed after a fraction of eccentric turn less than 180 °, for example about 90 °. Said first fraction of a turn, at the end of which the pawl begins to be released from the latch stopper, maybe then reduced accordingly. It follows that, for a rotational speed data of the gear motor group, the total duration of the opening cycle of the lock can be reduced compared to the case where the value of the first fraction of a turn is 180 ° or slightly more.

In an advantageous embodiment of the lock according to the invention, this can include a third stop which is fixed relative to the axis and against which the first stop is resting in the closed state of the lock. Preferably, said third stop is arranged in such a way that, in the closed state of the lock, the first and second axes of rotation and the contact edge have traces, in a common perpendicular plane P, which constitute the vertices of a flattened triangle such that, when the eccentric is driven in rotation to open the lock, said second axis crosses the plane defined by the first axis of rotation and the contact edge, the trace of said plane in the perpendicular plane P forming the base side of said flattened triangle. Under these conditions, the force exerted by the seal of door on the door and transmitted by the latch to the ratchet in the closed state of the lock will keep the first stop pressed against the third stop and the pawl will be well maintained in its locking position.

• la figure 1 montre, vue en plan de manière schématique, une serrure à assistance électrique selon l'invention, les divers éléments de la serrure étant représentés dans des positions correspondant à l'état fermé de ladite serrure ;
• les figures 2 à 5 sont des vues semblables à la figure 1, montrant différentes positions occupées par les éléments de la serrure au cours d'un cycle d'ouverture de cette dernière ;
• la figure 6 est un chronogramme illustrant, de manière comparative, le fonctionnement d'une serrure classique à assistance électrique et le fonctionnement de la serrure à assistance électrique selon l'invention.

Other characteristics and advantages of the invention will emerge more clearly during the following description of an embodiment of the lock, given by way of purely illustrative and nonlimiting example, with reference to the attached drawing. On this drawing:

• Figure 1 shows, in schematic plan view, an electrically assisted lock according to the invention, the various elements of the lock being shown in positions corresponding to the closed state of said lock;
• Figures 2 to 5 are views similar to Figure 1, showing different positions occupied by the elements of the lock during an opening cycle of the latter;
• Figure 6 is a timing diagram illustrating, in a comparative manner, the operation of a conventional electrically assisted lock and the operation of the electrically assisted lock according to the invention.

The lock 1 shown in Figures 1 to 5, intended for a door of a motor vehicle, essentially comprises, of in a manner known per se, a bolt 2, a pawl 3 and a gear motor assembly 4 coupled to the ratchet 3 to move it from the position of locking or closing shown in Figure 1 at the position of unlocking or opening shown in figure 5.

The bolt 2 is shown pivoting on an axis 5 fixed to a plate (not shown), which can itself be fixed on the edge free from door 6 of the vehicle. The bolt 2 has two notches 7 and 8 can cooperate with the pawl 3, as well as a fork 9 which, in the closed state of lock 1, receives and traps a keeper 11 which is rigidly attached to the vehicle body, for example to a door jamb 12, as symbolically represented by the dashed line 13. In practice, keeper 11, which can have, for example, in a manner known per se, the shape of a cylindrical tenon with head and can be attached to another plate (not shown), which is itself fixed to the vehicle body in the rebate of the bay door.

A spring 14 biases the bolt 2 in the direction of the arrow F1 so as to place it in a position roughly corresponding to that shown in Figure 5 when the lock 1 is in the open state. This position of the bolt can be optionally defined, so known, by a stop (not shown). Although spring 14 is here shown schematically in the form of a coil spring of traction, it could also be carried out, in a known manner, in the form a spiral spring placed around axis 5.

The pawl 3, which is pivotally mounted in a manner that will described in detail below, has a latching finger 15 which is in engagement with the catch 8 of the bolt 2 in the closed state of the lock 1 (Figure 1).

In Figure 1, there is also shown, so schematic, a door seal 16 as well as an emergency mechanism 17, hand operated, allowing lock 1 to be opened in the event of electrical failure. The emergency mechanism 17 is here represented under the form of a bent lever, which can pivot around an axis 18 under the action of a command symbolized by arrow 19, but it could be performed in any other known manner.

In the closed state of door 6 and lock 1 (Figure 1), the door seal 16 is strongly compressed. By reaction, it applies therefore at door 6 a force F2 which tends to open this door. However, as the pawl 3 is engaged with the catch 8 of the bolt 2, it prevents it from pivoting in the direction of arrow F3 around the axis 5; since the keeper 11 is in the fork 9 of the bolt 2 and that it is integral with the door jamb 12, it prevents the door 6 from open up. At the same time, by reaction, the strike 11 exerts on the bolt 2 a force F4 proportional to the force F2. This force F4, combined to the force of the spring 14 (the intensity of which is usually much higher weak than that of forces F2 and F4), tends to rotate the bolt 2 in the direction of the arrow F3 around the axis 5. As a result, the bolt 2 is strongly pressed against the latching finger 15 of the pawl 3. This is the reason why in classic locks where the ratchet 3 is mounted pivoting around a fixed axis, the gear motor coupled to ratchet 3 must produce, when opening lock 1, a torque very important to overcome friction between contact surfaces of the snap-in finger 15 of the pawl 3 and of the catch 8 of the bolt 2 in order to release the latter.

To remedy this, the invention provides for coupling the gear motor 4 to the pawl 3 via an eccentric 21. This eccentric 21 can pivot around the axis of rotation 27 of a shaft 22 which is mechanically coupled to the gear motor 4 as is symbolically represented by the dashed link 20 in FIG. 1. The axis 27 of this shaft 22 occupies a fixed position relative to the axis of pivot 5 of the bolt 2. The pawl 3 is pivotally mounted on the axis eccentric 28 of a shaft or crank pin 23 of the eccentric 21. The assembly pivoting of the pawl 3 around the axis 28 can be ensured by through a friction bearing or, preferably, by via a ball or needle bearing (not shown), to reduce friction and therefore efforts. However, if for reasons of economy, the lock has only one bearing, this will preferably be placed at axis 27 because the impulse generated by the starting torque must allow to drive in first the axis 27 of the eccentric in the kinematic chain. Well of course, we can plan to mount a bearing at both axes 27 and 28.

The eccentric 21 carries a stop 24, which, in the closed state of the lock (Figure 1), is in contact with a stop 25 fixed by relative to axis 5. During an opening cycle of the lock, the stop 24 can come into contact with a stop 26 carried by the pawl 3. The fixed stop 25 can be, for example, formed by a locking pin carried by the plate which supports the elements of lock 1. The stop fixed 25 is arranged so that, in the closed state of the lock, the axis 27 of the shaft 22, the axis 28 of the shaft 23 and the contact edge 29 between the pawl 3 and the bolt 2 constitute the edges of a very trihedron flattened, the section of which by a plane P perpendicular to said edges is a very flattened triangle as shown in figure 1. The point which represents the trace of the axis 28 in said plane P is then above from line 31 which, in plane P, joins the points representing the traces of the axis 27 and the edge 29 in the same plane P. On the drawing, the plane P is the plane of FIGS. 1 to 5. Under these conditions, the pressure which is exerted by the bolt 2 on the pawl 3 and which is generated, as indicated above, by the reaction force exerted on door 6 by compressed seal 16, tends to rotate the eccentric 21 around the axis 27 in the direction opposite to the arrow F5. As a result, the stop 24 is held in abutment against the fixed stop 25 and that the lock 1 is blocked in its closed state.

Now, if the gear motor 4 is started so rotate the eccentric 21 in the direction of arrow F5 around the axis 27, the eccentric 21 begins by pushing the pawl 3 against the latch 8 of bolt 2, which has the effect of exerting on the latter a force F6 (figure 1). Due to the presence of the strike 11 in the fork 9 of the bolt 2, the latter then swings around the strike 11, so that door 6 closes more and door seal 16 is momentarily supercharged as shown in Figure 2. This first phase of the opening cycle of lock 1, during which slightly overcompresses the door seal 16, is relatively short, because it corresponds to an angle of rotation of a few degrees from eccentric 21 around axis 27 and ends at moment when the traces in the plane P of axes 27, 28 and the edge of contact 29 are coplanar in a plane Q, the trace of which in the plane P is line 31 (Figure 2). At this time, the force F6 which was applied by the pawl 3 to the bolt 2 due to the rotation of the eccentric 21, stops growing.

On the other hand, as soon as the axis 28 of the shaft 23 has crossed the plane Q (the eccentric 21 continuing to rotate around the axis 27 in the direction of arrow F5), as shown in FIG. 3, the force F7, which is exerted by the bolt 2 on the pawl 3 and which is generated by the reaction force of the compressed seal 16 on the door 6, is transmitted to the shaft or crank pin 23 of the eccentric 21. The moment of this force F7 relative to the axis 27 of the eccentric 21 forces the latter to turn in the direction of arrow F5, i.e. in the same direction as the direction of drive of the gear motor 4. Consequently, the energy stored by compression in door seal 16 is now restored and contributes with the gear motor 4 to rotate the eccentric 21, to the point that there is practically no need for supply electrical power to the gear motor 4 so that it does turn the eccentric 21, the rotation of the latter can be ensured practically only by the energy stored in the joint 16.

During this phase of the lock opening cycle 1, the eccentric 21 forces the pawl 3 to move back relative to the notch stop 8 of bolt 2, substantially in the direction of line 31 and force F7 until eccentric 21 arrives in position shown in Figure 4. In this position, the axes 28, 27 and the edge of contact 29 are coplanar and their traces in the plane P are aligned in this order on line 31, i.e. axis 27 is between the axis 28 and the contact edge 29. During this last phase of rotation of the eccentric 21, the door 6 is ajar and the door seal 16 is decompressed. For example, as already indicated above, the eccentric 21 can be dimensioned in such a way that the door seal 16 is completely decompressed when the eccentric arrives in the position shown in Figure 4 or a shortly before this time. The stop 26 is disposed on the pawl 3 such so that the stop 24 carried by the eccentric 21 comes into contact with the stop 26 when the three tracks 28, 27 and 29 are aligned in this order (Figure 4). However, if the door seal 16 is completely decompressed before eccentric 21 reaches position shown in Figure 4, the stop 26 could be disposed on the pawl 3 in such a way that the stop 24 comes into contact with it earlier, that is to say for an angle of rotation of the eccentric 21 less than 180 ° relative to the position shown in Figure 2.

As soon as the stop 24 carried by the eccentric 21 arrives at contact with the stop 26 carried by the pawl 3, this stop 24 then acts as a "knock" of training (or coaching element), to oblige the pawl 3 to be pivoted at the same time as the eccentric 21 around the axis 27 of the latter, as indicated by the arrow F8 in FIGS. 4 and 5, so that the pawl 3 releases the bolt 2. As soon as the pawl 3 has released bolt 2, it pivots in the direction of arrow F3 under the action of return spring 14 to release the keeper 11 and allow opening door 6 as shown in figure 5.

When the pawl 3 has turned enough to release bolt 2 completely, it is possible to have the eccentric 21 is stopped by a fixed stop, which can be the stop 25 or another stop, and that the geared motor 4 and the eccentric 21 are returned to their starting position (figure 1) or by feeding reverse of the gear motor 4, either by a return spring (not shown).

From the above, we see that the gear motor 4 of lock 1 according to the invention must provide a torque of some importance and therefore consume energy, only during the over-compression phase of the door seal 16, that is to say while the eccentric 21 passes from the position shown in the figure 1 at the position shown in Figure 2. During the rest of the cycle opening of lock 1, or the mechanical energy stored in the compressed door seal 16 adds or replaces energy mechanical produced by the gear motor 4 to rotate the eccentric 21 from the position shown in Figure 2 to the position shown in Figure 4, or the gear motor 4 has practically more resistance to overcome (after seal 16 has been decompressed - Figures 4 and 5), so that it consumes practically no more energy electric to rotate the eccentric 21.

The gear motor 4 of the lock according to the invention therefore consumes less energy than that of a conventional lock electric assistance, in which the pawl 3 pivots about an axis fixed. This can be better understood using the chronogram of the figure 6. The upper part of this chronogram relates to the operation of a conventional lock, while the lower part of the timing diagram relates to the operation of the lock according to the invention.

In the upper line of this timing diagram, phase I is the release phase, i.e. the phase during which the gear motor rotates the pawl around its pivot axis so as to slide his locking finger on the stopper of the bolt. During this phase I, the gear motor must produce a strong torque to overcome the friction between the pawl 3 and the bolt 2, so it spends significant energy as it is indicated by the sign - in zone A of the timing diagram. Phase II is an ejection phase, i.e. the phase in which the door seal push back the door after, in the conventional lock, the pawl 3 has released the bolt 2; in this phase II, the door seal provides a certain energy as indicated by the + sign in area B of the timing diagram. However, the energy supplied by the door seal is spent practically in pure loss since it only serves to repel the door without helping the gear motor to rotate the pawl.

In the lower part of the timing diagram in Figure 6, phase I 'corresponds to the overcompression phase of the door seal 16, which is the only phase during which the gear motor 4 of the lock 1 according to the invention must produce a relatively torque important and therefore spend energy as indicated by the sign - in zone C of the timing diagram. Phase II 'is here another ejection phase during which the door seal 16 pushes back door 6 (this phase roughly corresponds to the passage of the eccentric 21 from the position of figure 2 to the position of the figure 4). Throughout this phase II ', the door seal restores, like this is indicated by the + sign in area D of the timing diagram, the energy that it had stored by compression and this energy is used not only to push door 6 back, but also to rotate the eccentric 21, so that the overall electrical energy at supply to the gear motor 4 can be greatly reduced.

Lock 1, which has been described above, provides an electric assistance when opening the lock, but it can just as easily also provide electrical assistance when closing the lock. In the latter case, contrary to what was indicated above, at the end of the lock opening cycle, the eccentric 21 is brought back not to the starting position of the Figure 1, but in the position shown in Figure 4, in which the stop 24 has come into contact with the stop 26, and it remains in this position waiting for the door to close. In this way, when a user closes the vehicle door by "slamming" it, the pawl 3 is free to disappear in its unlocked position, against the action of its own return spring (not shown), in sliding on the edge of the bolt 2 which pivots in the opposite direction to the arrow F3 under the action of the strike 11. It will be noted that the lock 1 can be easily closed on the second notch, i.e. on notch 8 of the bolt 2, simply by slamming the vehicle door, because the pawl 3 is at this backward moment and door seal 16 is decompressed, as shown in FIG. 4. A position sensor, for example a contactor of limit switch, can be provided, in a manner known per se, for detecting the arrival of the bolt 2 in its closed position shown in the figure 4, in order to restart the gear motor 4 running in the opposite direction in the sense that it had during the opening cycle of lock 1, that is to say in the opposite direction to arrow F5. It follows that the eccentric 21 pushes the pawl 3 and the bolt 2 in the direction of arrow F6 of the Figure 1 and the door seal 16 is then compressed until the three traces 27, 28 and 29 line up on line 31 as shown in Figure 2. As soon as trace 28 has crossed line 31 in the direction opposite to that of arrow F5, the door seal 16 helps the gear motor 4 rotate the eccentric 21 until the stop 24 of the latter comes into contact with the fixed stop 25 (Figure 1). At this moment, the power supply of the gear motor 4 can be cut.

Note that during electrical assistance to the closing, the gear motor 4 is not used to rotate the pawl 3 of its unlocked position to its locked position but it serves only compress the door seal 16. The pawl 3 comes automatically in its locked position simply by slamming the door of the vehicle. As a result, even in the event of a breakdown current supply of the gear motor 4, the lock 1 according to the invention can nevertheless be closed at the second notch 8 of the bolt 2. Although in this case the door seal 16 is not compressed, this nevertheless offers vehicle occupants a better guarantee than the lock will remain closed in the event of a vehicle collision with another vehicle or with a fixed obstacle. Indeed, the closure on the second notch 8 of bolt 2 always resists better than closing the first notch 7 of said bolt. In this regard, the lock 1 according to the invention provides therefore a definite advantage compared to conventional locks in which, for closing assistance, the gear motor acts not not on the ratchet but on the bolt, and in which, in the event of a breakdown power supply to the gear motor, the lock cannot be closed only at the first notch of the bolt.

It goes without saying that the embodiment of the invention which has been described above was given as a purely indicative example and in no way limitative, and that many modifications can be easily brought by those skilled in the art without leaving the part of the invention. In particular, this is how lock 1 could be fixed to the door jamb 12 and the striker 11 to the door 6. In addition, although the invention has been described more particularly with regard to a door lock for motor vehicle, it could be used in all cases where a seal is strongly compressed between a door and a fixed chassis and where one wishes to have an electric assistance to open the door lock.

Claims (4)

Electrically assisted door lock, in particular for a motor vehicle, of the type comprising: a bolt (2) which can pivot about an axis (5) and provided with at least one stop notch (8), a pawl (3) which can pivot about the axis of a shaft parallel to the axis (5) between a locking or closing position, in which said pawl is engaged with a catch notch of the bolt along an edge contact (29) substantially parallel to the axis (5), and an unlocking or opening position, in which said pawl is out of engagement with said catch, and an electric motor (4) coupled to said pawl (3) to rotate it from its first position to its second position, characterized in that the electric motor (4) is coupled to the pawl (3) by means of an eccentric (21) which can be rotated by the electric motor (4) via a shaft (22) the axis (27) of which is said to be the first axis of rotation, the said axis (27) having a fixed position relative to the axis of the pivot (5) of the bolt (2), the eccentric (21) carrying a shaft ( 23) whose axis (28) is said to be the second axis of rotation, said second axis (28) being eccentric with respect to the first axis (27), the pawl (3) being pivotally mounted on said shaft (23), a first stop (24) being carried by the eccentric (21) and a second stop (26) being carried by the pawl (3), so that, starting from the closed state of the lock (1), when the eccentric (21) is rotated by the electric motor (4) for a first fraction of a turn, said eccentric causes the pawl (3) to move relative to the latch (8) of the bolt (2) substantially in a d irection defined by a line (31), which constitutes the trace of the plane defined by the first axis of rotation (27) and the contact edge (29) in a common perpendicular plane P, until the first stop ( 24) comes into contact with the second stop (26), after which, when the eccentric (21) continues to rotate for a second fraction of a turn around the first axis of rotation (27), it drives with it the pawl (3 ) by rotating it around the second axis of rotation (28) in order to release the pawl (3) from the catch (8) of the bolt (2). Lock according to claim 1, characterized in that the first stop (24) is arranged in such a way that, when it comes into contact with the second stop (26) at the end of said first fraction of a turn, the contact edge (29) between the pawl (3) and the stop notch (8) is substantially in the plane defined by the first (27) and second (28) axes of rotation, on the side of the first axis (27) where is not the second axis (28). Lock according to one of claims 1 or 2, characterized in that it comprises a third stop (25) which is fixed relative to the axis (5) and against which the first stop (24) is resting in the closed state of the lock (1). Lock according to claim 3, characterized in that said third stop (25) is arranged so that, in the state closed of the lock, the first (27) and second (28) axes of rotation and the contact edge (29) have traces, in a perpendicular plane common P, which constitute the vertices of a flattened triangle such that, when the eccentric (21) is rotated to open the lock (1), said second axis (28) crosses the plane defined by the first axis of rotation (27) and the contact edge (29), the trace of said plane in the plane perpendicular P forming the base side of said flattened triangle.

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