BELT RETRACTOR WITH AN ELECTRICALLY OPERATED BLOCKING DEVICE

Description

[0001] The present invention relates to a belt retractor with an electrically actuated blocking device having the features of the preamble of claim 1.

[0002] A generic electrically operated blocking device is known, for example, from GB 2 398 824 A.

[0003] Such blocking devices serve to stop an externally toothed control disc, which is rotatably mounted on a belt shaft of the belt retractor, by engagement of a blocking lever relative to the belt shaft and thereby force a blocking pawl to move into a toothing fixed to the vehicle, which in turn blocks the belt shaft in the extension direction.

[0004] In conventional mechanical locking devices, an inertial mass is mounted on a contact surface. This mass is deflected when a predetermined vehicle deceleration is exceeded, thereby deflecting the locking lever and forcing it to engage the toothing of the control disc. Such mechanical locking devices are also referred to as vehicle-sensitive sensor devices. One problem with these mechanical locking devices is that the inertial mass must always be aligned in a defined orientation on the contact surface relative to the vehicle's longitudinal and transverse axes, regardless of the installation geometry of the belt retractor, to prevent the belt shaft from being inadvertently blocked.This means that the belt retractor must be designed for each individual vehicle. The alignment of the contact surface and the mass resting on it in relation to the belt retractor must be individually designed so that it corresponds to the specified alignment, taking into account the installation geometry of the belt retractor in the vehicle. Furthermore, with belt retractors integrated in the front seats, such as in convertibles, there is the problem that the inertial mass is inadvertently deflected on the contact surface when the angle of the backrest is adjusted or when the backrest is folded forward to allow access to the rear seats. This causes the blocking lever to inadvertently move into the external toothing of the control disc. This blocks the belt retractor in the extension direction and the backrest cannot be swivelled any further, or the occupant cannot fasten their seat belt. To avoid this, additional switch-off mechanisms orCompensating mechanisms must be provided, but these must only be effective in these cases, so that the occupant is restrained in the event of an accident. These challenges make such a mechanical locking device very complex.

[0005] In the case of an electrically operated blocking device, as known from GB 2 398 824 A, for example, the movement of the blocking lever is controlled electrically, which eliminates the previously required inertial mass. The belt retractor can therefore be mounted in various positions in the vehicle and also in backrests. Furthermore, the blocking of the belt shaft can be controlled by an electrical signal from a control device. The signal can be generated by a control device which can also generate the signal in response to other sensor devices or control systems. For example, it is conceivable to block the belt shaft automatically when a driving dynamics assistance system is activated, which is controlled, for example, in response to a signal from an optical sensor device.This also controls the electrical locking device directly or indirectly depending on the signal from the optical sensor device. Furthermore, the electrically actuated locking device can be operated in any orientation and configuration, as it is not actuated by inertial forces and therefore does not need to be aligned in a specific direction relative to the vehicle's direction of travel. It can therefore also be preferably installed in seats of at least partially autonomous vehicles, which the occupant can adjust over considerably larger adjustment ranges for improved communication with other occupants, for alignment in a rest position, or generally to utilize the freedom gained through autonomous driving, compared to seats in conventional, non-autonomous vehicles.

[0006] An electrically actuated blocking device 100 used by the applicant in its products, which corresponds to the embodiment of GB 2 398 824 A, is described in the Figure 1 and 2 This document discloses a belt retractor having the features of the preamble of claim 1.

[0007] The electrically actuated blocking device 100 comprises as basic elements a housing 1 with an L-shaped basic structure with a base plate 15 and a first upright leg 16, a blocking lever 2 pivotally mounted on the first upright leg 16 of the housing 1, an electromagnet 3 and a first spring 4, which is held at one end on the housing 1 and is connected at the other end to a lever arm 22 of the blocking lever 2 projecting outward from the first upright leg 16. The first spring 4 is designed as a tension spring such that it preloads the blocking lever 2 into a position in which it engages with a blocking tip 25 in a toothing 26 of a control disk 21 and thereby holds the control disk 21 relative to the belt shaft 20. The control disk 21 with the toothing 26 is only in the Figure 9in a belt retractor according to the invention. Thus, when the belt shaft 20 rotates in the extension direction, the blocking pawl is automatically forced to engage a toothing fixed to the vehicle, and the belt shaft 20 is subsequently blocked against further belt webbing extension. The blocking lever 2 comprises a contoured part 24 and a steel plate 5, wherein the steel plate 5 faces the electromagnet 3, so that when the electromagnet 3 is energized, the blocking lever 2 is attracted by it and thus pulled out of the toothing 26 of the control disk 21. The belt shaft 20 can therefore subsequently rotate freely in the extension and retraction directions. The advantage of this solution is that the belt shaft 20 is blocked in the extension direction even in the event of a power failure or a defect in the electromagnet 3, and the occupant is safely restrained in this case too.

[0008] The electromagnet 3 comprises a base component 6 with a columnar central section 7 and two radial flanges 8, each of which projects radially outward at one of the ends of the central section 7. The electromagnet 3 is held by the base component 6 on the base plate 15 of the housing 1. The base component 6 has a tubular passage section 14 in the central section 7 and an annular space 9radially outward on the central section 7, wherein the annular space 9 is delimited towards the ends of the central section 7 by the radial flanges 8. Furthermore, the electromagnet 3 comprises a coil 10 with a plurality of turns, which is arranged in the annular space 9 and is electrically contacted with an external control device via lines 11 provided in the base component 6. In addition, the electromagnet 3 comprises a first iron core 12, which is arranged in the tubular passage section 14 of the base component 6 and has a free end facing the steel plate 5 of the blocking lever 2.

[0009] When the coil 10 is energized, the blocking lever 2 is attracted by closing a first magnetic circuit 1, defined by the first upstanding leg 16 of the housing 1, the first iron core 12 and the sections of the blocking lever 2 and the base plate 15 between the first iron core 12 and the first upstanding leg 16, as shown in the right-hand illustration of the Figure 2 can be seen. Furthermore, a damping element 13 in the form of a soft tube, e.g. in the form of a short piece of hose, is provided, which is clamped at its ends between two extensions of the radial flange 8 facing the blocking lever 2. The damping element 13 is positioned so that the blocking lever 2 does not rest with its free end on the damping element 13 in the deflected position (left illustration of the Figure 2) and only in the tightened position does it come into contact with the central soft section of the damping element 13 between the clamping points (right illustration of the Figure 2 ). This dampens the tightening movement of the locking lever 2 in the final phase of the movement. This dampening creates a soft stop and prevents annoying "rattling noises" during the tightening movement and possible subsequent slight movements of the locking lever 2.

[0010] The object of the invention is to provide a belt retractor with an electrically actuated blocking device which is improved with regard to the blocking process.

[0011] To achieve this object, a belt retractor having the features of claim 1 is proposed. Further preferred embodiments of the invention can be found in the subclaims, the figures, and the associated description.

[0012] According to the basic idea of ​​the invention, it is proposed that a second spring is provided, which is arranged in such a way that the blocking lever, regardless of its

[0013] Position with its blocking arm and is tensioned by the blocking arm during a pivoting movement from the toothing of the control disc.

[0014] The proposed solution has several advantages. A first advantage is that the second spring is tensioned by the pivoting movement of the blocking lever out of the toothing of the control disc, so that the blocking movement of the blocking lever during the pivoting movement into the toothing of the control disc is supported in addition to the force exerted by the first spring and by the force exerted by the second spring during relaxation. This can reduce the time required to block the control disc and thus also the time required to block the belt shaft, for example, to a value of less than 4 ms. A further advantage is that the blocking lever rests on the second spring regardless of its position, so that firstly the movement of the blocking lever is triggered immediately and secondly unwanted rattling noises are permanently avoided regardless of the position of the blocking lever.Furthermore, the blocking lever is fixed in position regardless of its position due to the permanent contact with the second spring, and adverse movements of the blocking lever can be avoided.

[0015] It is further proposed that the second spring supports the blocking lever in the area of ​​the blocking arm on its side facing away from the control disc. The proposed further development allows the blocking lever to be subjected to a compressive force by simply resting on the second spring. An additional connection between the blocking lever and the second spring can thus be omitted. Furthermore, the blocking lever preferably rests on the second spring with the blocking arm, so that the blocking lever is subjected to a tensile force on both sides at two spaced-apart points on either side of its pivot bearing via the lever arm and a compressive force via the blocking arm.

[0016] It is further proposed that the second spring is fixed at a first and a second end, and that the blocking lever with the blocking arm rests against a spring section of the second spring arranged between the first and the second end of the spring. By being fixed, the second spring is fixed at its two ends to the blocking device relative to the blocking lever in the form of an abutment and, together with the spring section provided between the two fixed ends, simultaneously forms a resilient support surface for the blocking lever. The second spring is fastened at both ends to the blocking device in a tensile-resistant manner so that it is tensioned in the region of the spring section when the blocking lever is tightened, and the tensioning force generated in the spring is absorbed by the blocking device via the two fixed ends.

[0017] Furthermore, the blocking arm can preferably have a profile structure adapted to the surface of the spring on the surface intended for contact with the second spring. This adapted profile or surface structure can increase the contact area between the blocking lever and the second spring. This adapted profile structure can be shaped such that it is adapted to the shape of the second spring in the tensioned state and / or also in the relaxed state. In this case, the shape of the surface of the blocking lever in the longitudinal direction of the second spring as well as in the transverse direction of the second spring are available for shaping the surface structure. In this case, the profile structure can be implemented, for example, in the form of one or two specifically designed curves in the surface of the blocking lever, i.e. it can be deliberately uneven.

[0018] It has been found that the profile structure can preferably be formed by a plurality of cams of different heights, with the cam with the greatest height being arranged centrally and the cams with the shorter height being arranged laterally and symmetrically to the central cam with the greatest height. Due to the shape of the proposed profile structure, the contact surface of the blocking lever is continuously enlarged from an initially smaller contact surface to a larger contact surface during tensioning of the second spring, so that tensioning of the spring can be achieved with an increasing spring force, which in turn also results in an increase in the braking force acting on the blocking lever.

[0019] Furthermore, the surface of the second spring can have a structure consisting of several grooves running perpendicular to the pivot axis of the locking lever. The proposed profiling has the advantage that the locking lever is better secured against lateral displacement relative to the second spring by the grooves.

[0020] It is further proposed that the second spring be formed by a coil spring. Coil springs can be manufactured very cost-effectively in large series and can be procured and installed as finished parts. They also have the advantage that, due to the windings, they already have a profiled surface structure with grooves, which can be used for the lateral positional fixation of the locking lever described above.

[0021] It is further proposed that the second spring be arranged at an angle of 5 to 15 degrees relative to the pivot axis of the blocking lever, which allows the length of the second spring to be extended while maintaining the same installation space width, thus improving the spring behavior. If a coil spring is provided, the proposed arrangement can additionally compensate for the pitch of the windings by arranging the coil spring at the same angle, opposite to the pitch of the windings. Thus, the second spring can be arranged so that the grooves between the windings are perpendicular to the pivot axis of the blocking lever.

[0022] It is further proposed that a stop damper be provided on the blocking lever and / or a fixed counter surface of the blocking device, limiting the pivoting movement of the blocking lever. The stop damper can further dampen the movement of the blocking lever in the final phase. In this case, any noise generated when the blocking lever comes into contact with the second spring can be further reduced by the damping properties of the stop damper. For this purpose, the stop damper can be made of, for example, a low-hardness plastic or an elastomer.

[0023] A particularly proven construction of the electromagnet can be realized in that the electromagnet has a coil with a through-opening, and an iron core is arranged in the through-opening, which, when a voltage is applied to the coil, exerts a magnetic force via the steel plate on the blocking lever and actuates it to trigger a blocking or unblocking movement against the force of the first spring.

[0024] Furthermore, in this case, it is proposed that the movement of the blocking lever is forced by at least a first magnetic circuit which is formed by the first iron core, the upstanding first leg and the sections of the base plate and the blocking lever between the first iron core and the upstanding first leg.

[0025] The invention will be explained below using a preferred embodiment with reference to the attached figures. Fig. 1 shows an exploded view of a belt retractor with an electrically actuated blocking device according to the prior art; and Fig. 2 shows an electrically actuated blocking device according to the prior art with a blocking lever in two different positions in a sectional view; and Fig. 3 shows a further developed electrically actuated blocking device in various views; and Figs. 4 to 8 show various enlarged sections of the further developed electrically actuated blocking device; and Fig. 9 shows a belt retractor according to the invention with a further developed blocking device with a blocking lever in two different positions in a side view.

[0026] In the Figure 3 an electrically actuated blocking device 100 further developed according to the invention can be seen, which is mentally inserted into the belt retractor known in the prior art and the blocking device 100 there of the Figure 1and 2 The further developed blocking device 100 corresponds in its basic structure to the one based on the Figure 1 and 2 described and known in the prior art blocking device 100, so that in this regard reference is made to the description in the introduction to the description and only the differing structural features of the further developed blocking device 100 and the resulting advantages are described below.

[0027] In the Figure 3 the further developed blocking device 100 can be seen in a position with the blocking lever 2 deflected, which corresponds to the one shown in the left illustration of the Figure 2 The position of the blocking device 100 can be seen in the figure. In the left illustration of the Figure 9The same further developed blocking device 100 can be seen on a belt retractor according to the invention with a deflected blocking lever 2, while the right-hand illustration shows the same blocking device 100 with a non-deflected blocking lever 2. In the blocking position, the blocking lever 2 engages with a blocking tip 25 in the toothing 26 of the control disc 21, thereby blocking the control disc 21 relative to the belt shaft 20, so that the blocking pawl is forced into the control movement into the vehicle-fixed toothing of the belt retractor, blocking the belt shaft 20 in the extension direction. The belt shaft 20 is then subsequently blocked in the extension direction of the seat belt wound thereon.

[0028] Instead of the previously provided damping element 13 (see Figure 1 and 2) a second spring 17 is now provided, which is held by its two ends 18 and 19 on opposite extensions of the radial flange 8 facing the blocking lever 2. The second spring 17 is designed as a helical spring with a large number of turns and grooves 33 arranged between them on the surface and has a spring section 27 provided between the two ends. The second spring 17 is arranged such that, with the spring section 27, it supports the blocking lever 2 on the profile structure 28 provided on the underside of the blocking arm 23. The blocking lever 2 thus rests against the second spring 17 even in the deflected position and finds an elastic abutment in it, so that it is fixed in position even in the deflected position, i.e. is secured against unintentional pivoting out of the toothing due to the spring force exerted by the second spring 17.The second spring 17 is arranged here at an angle of 5 to 15 degrees to the pivot axis of the blocking lever 2, i.e. slightly diagonally opposite it, whereby the spring length can be increased with the same installation width. Furthermore, if the second spring 17 is aligned opposite to the pitch of the coils of the helical spring, the pitch of the coils can be compensated so that the grooves 32 between the coils are aligned perpendicular to the pivot axis of the blocking lever. The coils with the grooves 33 formed between them form a surface structure which secures the blocking lever 2 against lateral slipping relative to the second spring 17. If the second spring 17 is not designed as a helical spring, e.g. as a leaf spring, this surface structure can also be in the form of depressions in the second spring 17.The second spring 17 is preferably made of metal so that its properties are less dependent on temperature and are more resistant to aging than when using a plastic spring.

[0029] Furthermore, in addition to the first upright leg 16, a second upright leg 35 is provided on the base plate 15, opposite the first leg 16, via which a second magnetic circuit can be closed to increase the attractive force of the electromagnet 3. Furthermore, the second leg 35 can also serve to support the upper radial flange 8 or, alternatively, to hold the second spring 17. However, the holder of the second spring 17 on the radial flange 8 of the electromagnet 3 is advantageous in that in this case it is arranged on the part which exerts the attractive force on the blocking lever 2 when the electromagnet 3 is energized, so that the movement of the blocking lever 2 is directly cushioned when the electromagnet 3 is energized.

[0030] In the second leg 35, an elongated hole 34 is provided for fastening the blocking device 100 to the belt retractor, in particular to a housing of the belt retractor, as can also be seen in the enlarged illustration of the Figure 6 can be seen. An identical elongated hole 34 can also be provided in the first upright leg 16, so that the blocking device 100 can also be held on both sides.

[0031] Furthermore, a stop damper 33 is provided on the underside of the blocking lever 2, on the side of the steel plate 5 facing the radial flange 8. The lines 11 are designed here as contact pins extending vertically downwards in the form of dimensionally stable metal pins, as in the Figure 5 can be seen.

[0032] When the electromagnet 3 is energized, the blocking lever 2 is attracted by the magnetic force exerted by the electromagnet 3 on the steel plate 5 and thereby pivots with its blocking tip 25 out of the toothing 26 of the control disc 21. The control disc 21 is thereby released and, due to its spring load, rotates back by a small angle of rotation relative to the belt shaft 20, thereby pulling the blocking pawl out of the vehicle-fixed toothing so that the belt shaft 20 can then rotate freely in the extension and retraction directions. At the same time, the first spring 4 and the second spring 17 are tensioned by the tightening movement of the blocking lever 2. The blocking lever 2 tensions the first spring 4 via the lever arm 22, exerting a tensile force. At the same time, the blocking lever 2 with the blocking arm 23 exerts a compressive force on the second spring 17 lying on its underside, whereby this spring is deformed in an arc shape in the direction of the base plate 15.The blocking arm 23 of the blocking lever 2 has on its underside a profile structure 28 consisting of three cams 29, 30 and 31, which have a different height, as shown in the . Figure 4can be seen. The cam 29 with the greatest height is arranged centrally between the two cams 30 and 31 with the smaller, identical heights. Furthermore, the two cams 30 and 31 with the smaller, identical heights are arranged symmetrically to the middle cam 29 with the greater height, i.e. at an identical distance from it. As a result, during the tightening movement of the blocking lever 2, the second spring 17 is first tensioned via the middle cam 29, and the two cams 30 and 31 with the smaller height only come into contact with the second spring 17 later and preferably simultaneously. As a result, the second spring 17 is tensioned successively via the cams 29, 30, 31, and the tightening movement of the blocking lever 2 is braked more strongly towards its end by an increasing spring force. The cams 29, 30, 31 thus form, in the connection of the highest points or lines of their front sides, a surface adapted to the curvature of the tensioned second spring 17.Of course, the cams 29, 30, 31 can additionally also have a surface which is concavely curved in its longitudinal extent and which is adapted to the curvature of the second spring 17 in its cross-section, so that the cams 29, 30, 31 bear against the second spring 17 over a larger area of ​​the circumference.

[0033] On the underside of the blocking arm 23 of the blocking lever 2, a stop damper 33 is also provided, which is directed towards the upper side of the radial flange 8 of the electromagnet 3 and prevents the blocking lever 2 from coming into direct contact with its steel plate 5 with the radial flange 8 even under the most unfavourable circumstances, as shown in the Figure 7can be seen. The stop damper 33 has a tip with which it initially comes into contact with the surface of the radial flange 8, and which, due to its shape, causes increasing damping of the blocking lever 2 during the tightening movement. The stop damper 33 can be formed, for example, from a low-hardness plastic, an elastomer, or the like.

[0034] In the Figure 8 The mounting of the blocking lever 2 on the upright first leg 16 can be seen. The blocking lever 2 is provided with a protruding arm to the side, forming a gap 2b. The first leg 16 is provided with an upright arm 16a, which engages in the gap 2b. Thus, the blocking lever 2 is mounted laterally relative to the upright leg 16. Furthermore, the gap 2b simultaneously forms a stop for limiting the movement of the blocking lever 2 in the direction of the upright leg 16.

[0035] The second spring 17 is arranged obliquely with respect to the longitudinal axis of the blocking lever 2 at an angle other than 90 degrees, preferably at an angle of 5 to 15 degrees to the pivot axis of the blocking lever 2, so that with the same width of the blocking device 100, a longer second spring 17 with correspondingly softer spring characteristics can be used. If the second spring 17 is designed as a helical spring, the arrangement of the second spring 17 can compensate for the pitch of the coils to such an extent that the grooves 33 are aligned approximately perpendicular to the pivot axis of the blocking lever 2. As a result, the blocking lever 2 with the profile structure 28 finds improved hold on the spring 17 and is better secured against lateral slipping on the second spring 17.

[0036] The advantage of the second spring 17, in addition to cushioning the tightening movement, is that when the electromagnet 3 is deactivated, the second spring 17 in the tensioned position supports the blocking movement of the blocking lever 2 and, in addition to the first spring 4, also pushes the blocking lever 2 into the toothing 26 of the control disc 21. This can shorten the time required for blocking the control disc 21 and thus the blocking of the belt shaft 20 in the extension direction. The blocking lever 2 is thus driven by both the tensile force exerted by the first spring 4 and the compressive force exerted by the second spring 17 to perform the pivoting movement required for locking.

[0037] Overall, the movement of the blocking lever 2 can be realized by the provided second spring 17 and the compressive force exerted thereon, both during the tightening movement against the blocking device 100 and during the locking movement into the toothing 26 of the control disk 21, with significantly smaller inherent movements and thus in a significantly more controlled manner than was possible with the previously known solution in the prior art with only a first spring 4. In particular, due to the provided second spring 17, the blocking lever 2 is driven from two sides during the locking movement to the pivoting movement, wherein the torques exerted on the blocking lever 2 by the first spring 4 and the second spring 17 are added together.A further advantage of the invention is that the blocking lever 2 is still driven to the locking movement even if the first spring 4, for whatever reason, exerts no or only a lower spring force on the blocking lever 2, in that the blocking lever 2 is then driven to the locking movement via the second spring 17.

Claims

1. Belt retractor, comprising - a rotatably mounted belt shaft and - a toothed control disk (21) rotatably mounted thereon and - an electrically actuatable blocking device (100) having - a housing (1) with a base plate (15) and an upright first limb (16), and - a blocking lever (2) which is pivotably mounted in a pivot bearing of the upright first limb (16) and has a steel plate (5), - the electrically actuatable blocking device (100) stopping the control disk (21) with respect to the belt shaft, by means of an engagement of the blocking lever (2) in the toothing the control disk (21), and as a result forcing a blocking pawl to perform a movement in which it comes into engagement in a toothing of the belt retractor that is fixed to the vehicle and blocks the belt shaft in the pull-out direction, - the blocking lever (2) having a lever arm (22) that projects outward from the first limb (16) and on which a first spring (4) acts, which preloads the blocking lever (2) into a position in which it engages, with a blocking tip (25) arranged at the end of a blocking arm (23), in the toothing (26) of the control disk (21), and - an electromagnet (3) arranged in the housing (1), which exerts a force on the blocking lever (2) by energization, by means of which force said blocking lever is pulled out of the toothing (26) of the control disk (21) with the blocking tip (25), characterized in that - a second spring (17) is provided, which is arranged in such a way that the blocking lever (2) rests, with its blocking arm (23), against it irrespective of its position and is tensioned by the blocking arm (23) during a pivoting movement from the toothing (26) of the control disk (21).

2. Belt retractor according to claim 1, characterized in that - the second spring (17) supports the blocking lever (2) in the region of the blocking arm (23) on its side facing away from the control disk (21).

3. Belt retractor according to any of the preceding claims, characterized in that - the second spring (17) is fixed with a first and a second end (18, 19), and the blocking lever (2) rests, with the blocking arm (23), against a spring portion (27) of the second spring (17) that is arranged between the first and the second end (18, 19) of the second spring (17).

4. Belt retractor according to any of the preceding claims, characterized in that - the blocking arm (23) has, on the surface provided for resting against the second spring (17), a profile structure (28) adapted to the surface of the second spring (17).

5. Belt retractor according to claim 4, characterized in that - the profile structure (28) is formed by a plurality of cams (29, 30, 31) of different heights, the cam (29) of the greatest height being arranged centrally, and the cams of the lower height (30, 31) being arranged laterally and symmetrically with respect to the central cam (29) of the greatest height.

6. Belt retractor according to either claim 4 or 5, characterized in that - the surface of the second spring (17) has a structure consisting of a plurality of grooves (32) extending perpendicularly to the pivot axis of the blocking lever.

7. Belt retractor according to any of the preceding claims, characterized in that - the second spring (17) is formed by a coil spring.

8. Belt retractor according to any of the preceding claims, characterized in that - the second spring (17) is arranged at an angle of 5 to 15 degrees relative to the pivot axis of the blocking lever (2).

9. Belt retractor according to any of the preceding claims, characterized in that - an impact absorber (33) that limits the pivoting movement of the blocking lever (2) is provided on the blocking lever (2) and / or a fixed counter-surface of the blocking device (100).

10. Belt retractor according to any of the preceding claims, characterized in that - the electromagnet (3) comprises a coil (10) having a through-opening (14), and - an iron core (12) is arranged in the through-opening (14), which core, when a voltage is applied to the coil (10), exerts a magnetic force on the blocking lever (2) via the steel plate (5) and actuates the blocking lever counter to the force of the first spring (4) in order to trigger a blocking or unblocking movement.

11. Belt retractor according to claim 10, characterized in that - the movement of the blocking lever (2) is forced at least by a first magnetic circuit (I) which is formed by the first iron core (12), the upright first limb (16), and the portions of the base plate (15) and of the blocking lever (2) between the first iron core (12) and the upright first limb (16).