Safety device for a motor vehicle seat

p0001The invention relates to a safety device for a motor vehicle seat with the features of the preamble of claim 1.

p0002A safety device of this type has a seat surface which is typically formed by a seat cushion and on which a person using the corresponding motor vehicle seat can sit, as well as a movably mounted (adjustable) securing element associated with the seat surface, with a drive device which can be activated in a crash case From an initial position in such a way that it counteracts, together with the seat surface, the forward displacement of the basin of a person sitting on the seat surface in the seat longitudinal direction. The seat surface extends along a seat longitudinal direction which, in the installed state of the seat, corresponds in a motor vehicle, for example, essentially to the vehicle longitudinal axis (direction of travel of a motor vehicle)

p0003The seat surface forms on the one hand a component of the motor vehicle seat, to which the safety device is assigned; But at the same time it also forms part of the safety device itself since, together with the securing element, it is intended to limit the forward displacement of the basin of a person sitting on the seat surface. For this purpose, the securing element is brought closer to the seat surface (of the seat cushion) by means of the drive device, wherein, if appropriate, a certain deformation of the seat surface can also occur. However, the spatial position of the seat surface as a whole (for example by pivoting the seat surface) is not changed.

p0004By the cooperation of the securing element, which is moved out of its initial position, and the seat surface, it is intended to prevent a person who is strapped with a seat belt of the corresponding vehicle seat from slipping under the seatbelt, especially the lap belt, during a crash-induced forward displacement. This effect is also called "submarining" in English.

p0005In order to counteract the predecessor of the basin in the seat longitudinal direction of a person sitting on the seat surface in the event of a crash, a number of specific solutions are known from the prior art. It is common to all these solutions that a securing element is moved in the region of the seat surface of the motor vehicle seat in or shortly before a crash case in such a way that the securing element and seat surface limit the forward movement in the seat longitudinal direction of the basin of a vehicle occupant or allow it only within a controlled range .

p0006Such a vehicle seat is known, for example, from DE 100 11819 A1. There, the securing element is moved in the direction of the seat surface of the motor vehicle seat by means of a pyrotechnic drive in the event of a crash.

p0007Not all collisions of motor vehicles in road traffic will result in a total damage to the vehicle. Therefore, a large number of traffic accidents exist with a collision in the course of which the movement of the securing element from the initial position is activated and the vehicle is damaged in such a degree that repair of the damage occurring on the vehicle is still worthwhile. Furthermore, it is conceivable that an imminent collision which has ultimately been exerted is detected by a pre-crash sensor system present in the vehicle and activates the movement of the securing element from the initial position. In such cases, the motor vehicle seat known from the previously cited publication has the disadvantage that, in particular, the pyrotechnic drive device of the securing element of the motor vehicle seat must be replaced during the repair of the vehicle. This will result in additional repair costs.

p0008The present invention is therefore based on the object of providing a simple safety device for a motor vehicle seat which counteracts the pre-displacement of the basin of a person sitting on the motor vehicle seat in a crash case in a cost-effective manner without having the aforementioned disadvantages.

p0009This object is achieved by a safety device having the features of claim 1.

p0010According to the invention, it is provided that the drive device of the safety device has means for returning the securing element to the initial position, and the drive device ensures a renewed movement of the securing element in a new crash case after the safety element has been returned to the initial position.

p0011Thus, a motor vehicle seat is provided in which the movement of the securing element, which is also triggered as a feed movement, which is triggered in a crash case, is reversible. This means that the movement of the securing element can be reversed from the initial position after a first crash case and additionally the safety device provides the movement of the securing element from the initial position again in a second crash case.

p0012This has the advantage that it is possible in a simple manner, without the exchange of components of the drive device of the securing element, to simply reset the motor vehicle seat with the securing element and the drive device back into the original state after a crash case.

p0013A crash case is understood to mean both an actual collision and an imminent collision of a motor vehicle. The second variant is particularly relevant for motor vehicles whose safety system has a sensor system for detecting impending collisions (pre-crash sensors).

p0014The safety device according to the invention is particularly suitable for counteracting slipping of the person's pelvis in the seat longitudinal direction under a section of the safety belt arranged in the region of the pelvis in the case of a person strapped with a seat belt on the vehicle seat.

p0015The drive device preferably has a releasable barrier which blocks a return movement of the securing element into the initial position. The releasable barrier has the function of preventing forces acting on the securing element during a crash fall to move the securing element back in the direction of the initial position. After the crash case, the barrier can be released in order to move the securing element back into the initial position by means of the drive device.

p0016In a preferred variant of the safety device, the means for returning the securing element to the starting position comprise a spring device. This spring device is arranged in such a way that the securing element applies a force to the spring device during the feed movement of the securing element. After the crash case, the lock on the securing element can be released so that the spring force of the spring device moves the securing element back into the initial position. In this embodiment of the motor vehicle seat, the drive device preferably has a motor device for the feed movement of the securing element in a crash case. As motors for a motor device, all types of electric motors, in particular also electric motors, are suitable for producing a linear movement.

p0017In a second variant of the invention, the means for returning the securing element to the initial position is designed in the form of a motor device, and the drive device has a spring element for the feed movement of the securing element in a crash case. The spring element is thereby prestressed in the initial position of the securing element and secured by a holding device. In a crash case, the spring element is triggered by the holding device, and the spring force of the spring element is converted into the feed movement of the securing element. After the crash, the securing element can be guided back into the initial position by activating the motor device, the spring element being again prestressed and secured by means of the holding device.

p0018In a third variant, the motor device of the drive device serves both to move the securing element out of the initial position in the feed movement in a crash case and also to return the securing element to the initial position after the crash. The motor device thus serves both as a means for returning the securing element and as a means for the feed movement of the sliding element. An additional holding device as in the second variant of the motor vehicle seat is not required.

p0019In each of the three preceding embodiments, the drive device preferably has a transmission for force transmission and possibly transmission between the motor device and the securing element.

p0020The transmission may, for example, be a gear transmission (including toothed rack and toothed belt transmissions), a spindle transmission, a lever transmission, a belt transmission or a transmission using a flexible traction means.

p0021The securing element preferably extends below a padding of the seat surface substantially perpendicular to the seat longitudinal direction. In particular, the securing element can be arranged on a seat shell of the seat part. As a result, the securing element can be moved in the direction of the seat surface in a simple manner in a crash case, so that the seat surface and the securing element form a threshold which essentially acts along the direction of extension of the securing element and which is used for advancing the pelvis of a person sitting on the motor vehicle seat along the entire seat Width of the seat.

p0022For this purpose, the securing element preferably has an adjusting section which is brought into such a position during the feed movement of the securing element that it (together with the seat surface) delimits the forward displacement of the basin of a person sitting on the corresponding seat surface

p0023Furthermore, the securing element has at least one section, for example in the form of an end section, by means of which the securing element is guided along its direction of movement and on which the drive means can also attack.

p0024The feed movement of the securing element in a crash case can be designed as a translation, as a rotation or as a combination of a translation with a rotation. All three variants of the feed movement have in common that the securing element moves in the direction of the basin of the person sitting on the seat surface of the motor vehicle seat.

p0025In a first advantageous embodiment, the securing element moves purely translatively in a crash case. In this case, the securing element is designed essentially in the form of a strand. The motor vehicle seat has guide structures arranged opposite thereto on the side regions thereof which receive the two end sections of the strand-shaped securing element and serve to guide the translatory feed movement. A motor device is preferably arranged at each end section of the strand-shaped securing element. In the case of the first variant of the motor vehicle seat, this motor device serves exclusively for the implementation of the feed movement; For the return movement into the initial position, a spring device is then provided. In the reversed second variant, a spring element realizes the feed movement and the motor device serves to return the securing element. In the third variant, the motor device is used both for implementing the feed movement and for returning the securing element to the initial position.

p0026In a further preferred embodiment, a rotational feed movement of the securing element is provided. In this case, the securing element is constructed in the form of a bow. A straight-line pivoting section can in particular be provided between the two end sections of the bracket-shaped securing element. The bow-shaped securing element is pivoted with both end sections so as to be pivotable on the side areas of the vehicle seat in order to enable the rotary feed movement of the securing element in a crash case. The rectilinear pivoting range of the securing element acts on the seat surface during the feed movement such that the threshold forms on the seat surface which counteracts the forward displacement of the basin of a person sitting on the motor vehicle seat.

p0027In this case, a motor device is arranged in the region of at least one end section of the bracket-shaped securing element. This motor device serves, as described above, in the translatory feed movement for implementing the feed movement of the securing element and / or for returning the securing element to the initial position. For the variants in which the motor device is used only for the feed or return of the securing element, a spring element or a spring device is correspondingly provided for the respectively other movement.

p0028A further preferred embodiment of the motor vehicle seat is characterized in that the drive device has a strand-shaped traction means and the securing element is operatively connected to the motor device by means of the strand-shaped traction means. The strand-shaped traction means is used here to force the force exerted by the motor device on the securing element. A Bowden cable or a plastic strand with low self-extension can be used as a strand-shaped traction means.

p0029Due to the geometric mounting conditions on the motor vehicle seat, it may be advantageous to guide the strand-shaped traction means between the securing element and the motor device via at least one deflecting element. A deflecting roller can, for example, be used as the deflecting element.

p0030A further advantageous embodiment of the invention comprises a second strand-shaped traction means which is arranged between the motor device and an end portion of a lap belt provided on the motor vehicle seat such that the motor device in a crash case during the movement of the securing element realizes a tightening of the lap belt to the seat surface . This embodiment integrates the function of a belt tensioner in a simple and cost-effective manner.

p0031The strand-shaped traction means of the embodiments of the motor vehicle seat can be moved by means of the motor device either in a winding or translational manner in order to realize the desired feed and / or return movement of the securing element. When a second traction-type traction means is used, the rotational or translatory movement of the traction-type traction means additionally serves the belt tightening of the lap belt. A combination of a rotary and translatory movement of the strand-shaped traction means is also conceivable for achieving the above-mentioned effects.

p0032A further advantageous embodiment of the motor vehicle seat using a strand-shaped traction means is characterized in that the strand-shaped traction means is fastened by its first end to the securing element and by its second end by way of at least one deflecting element to an end portion of a lap belt provided on the motor vehicle seat In a crash case, the lap belt simultaneously tensions the strand-shaped pulling means towards the seat surface. In this way, the function of a belt tensioner can be easily and cost-effectively integrated into the motor vehicle seat.

p0033In all embodiments of the motor vehicle seat according to the invention, it is advantageous to make the securing element plastically deformable. In this case, it acts as a energy-absorbing element in a crash case in interaction with the basin of the person sitting on the seat surface. In particular, it is advantageous if the plastic deformation of the securing element occurs in a crash case essentially along the seat longitudinal direction with the goal of the controlled, braked movement of the basin.

p0034The drive device of the motor vehicle seat is preferably controllable by signals from a crash sensor in a motor vehicle. The motor vehicle seat can thus be easily integrated into the safety system of a motor vehicle.

p0035In this case, the drive motor of the drive device can be arranged centrally between two longitudinal sides of the seat surface of the corresponding motor vehicle seat, or alternatively two drive motors can be provided for moving the securing element which are arranged on one of the two longitudinal sides of the seat surface.

p0036Further features and advantages of the invention will become apparent from the following description of several exemplary embodiments with reference to the figures.

p0037Show it:<dl id="dl0001"><dt>FIG. 1a</dt><dd>Schematic view of a longitudinal section of a first embodiment of the motor vehicle seat with a rotatably movable securing element in the initial position;</dd><dt>FIG. 1b</dt><dd>1 a with the triggered securing element in the feed motion;</dd><dt>FIG. 2a</dt><dd>Schematic view of a longitudinal section of a second embodiment of the motor vehicle seat with a translationally movable securing element in the initial position;</dd><dt>FIG. 2b</dt><dd>2 a with the triggering element triggered in the feed motion;</dd><dt>FIG. 3a</dt><dd>Schematic view of a longitudinal section of a third embodiment of the motor vehicle seat with a translationally movable securing element in the initial position and belt tensioning;</dd><dt>3b</dt><dd>FIG. 3a shows a motor vehicle seat with a triggered securing element in the feed motion;</dd><dt>FIG. 4a</dt><dd>Schematic view of a longitudinal section of a fourth embodiment of the motor vehicle seat with a translationally movable securing element in the initial position and belt tensioning; </dd><dt>FIG. 4b</dt><dd>4 shows a vehicle seat from FIG. 4a with a triggered securing element in the feed motion;</dd><dt>FIG</dt><dd>Schematic view of a longitudinal section of a fifth embodiment of the motor vehicle seat with a rotatably movable securing element in the initial position and belt tightening;</dd><dt>FIG. 5b</dt><dd>FIG. 5a shows a motor vehicle seat with a triggered safety element in the feed motion;</dd><dt>FIG. 6a</dt><dd>Schematic view of a longitudinal section of a sixth embodiment of the motor vehicle seat with a rotatably movable securing element in the initial position and belt tightening;</dd><dt>FIG. 6b</dt><dd>Motor vehicle seat from FIG. 6a with triggered securing element in feed motion;</dd><dt>7a</dt><dd>Schematic view of a longitudinal section of a seventh embodiment of the motor vehicle seat with a rotatably movable securing element in the initial position and belt tensioning;</dd><dt>FIG. 7b</dt><dd>7a with triggered securing element in feed motion and FIG</dd><dt>FIG</dt><dd>A perspective view of a bow-shaped, energy-absorbing securing element;</dd><dt>9a and 9b</dt><dd>A perspective view and a side view of a seat part with a first concrete embodiment of a securing element which can be adjusted by means of a drive device;</dd><dt>FIG</dt><dd>2 shows a second concrete embodiment of a securing element which can be adjusted by means of a drive device in a perspective view; </dd><dt>Figures 11a and 11b</dt><dd>1 shows a further embodiment of a seat part with a concrete embodiment of a securing element which can be adjusted by a drive device in a perspective illustration and a side view;</dd><dt>FIG</dt><dd>4 shows a perspective view of a seat part with a fourth concrete embodiment of a securing element which can be adjusted by a drive device;</dd><dt>13a and 13b</dt><dd>A perspective view and a side view of a fifth concrete embodiment of a securing element which can be adjusted by means of a drive device.</dd></dl>

p0038FIG. 1a shows a schematic view of a longitudinal section along the seat longitudinal direction X of a first embodiment of a motor vehicle seat 1 with a safety device. In a known manner, the motor vehicle seat 1 has a backrest part 11 and a seat part 12 with a seat surface 10 arranged on the upper side of the seat part 12. The seat part 12 comprises a seat shell 13; On which a padding is provided. On the surface of the padding, in turn, the seat surface 10 is arranged. FIG. 1a shows the region from the knees to the neck, the thigh region and the pelvic region lying on the seat surface 10 of the seat part 12. The basin B of the seated person is shown schematically below a lap belt section 4 of a seat belt.

p0039A bow-shaped securing element 2 is arranged between the seat shell 13 and the seat surface 10 of the seat part 12 to form the safety device. Only one end section 24 in FIG. 1a can be seen between the end regions 24, 24 'of the securing element 2, one adjusting section 26 extending essentially perpendicularly to the longitudinal cutting plane extending in the form of a pivot section. The bow-shaped securing element 2 is pivoted with its end regions 24, 24 'on the side structure and / or seat shell 13 of the motor vehicle seat 1 so as to be pivotable.

p0040FIG. 1b shows the same sectional view as FIG. 1a, wherein the same elements of the motor vehicle seat are provided with the same reference symbols.

p0041The securing element 2 has a drive device 3 for generating a rotational movement of the adjustment section 26 in the direction of the seat surface 10 and the basin B of a person sitting on the motor vehicle seat 1 (rotational feed movement). The drive device 3 is designed in the form of a motor device 31 arranged on at least one of the end regions 24, 24 'of the bracket-shaped securing element 2. This motor device 31 at the same time forms the means which enable the safety element 2 to be returned to the initial position after a crash.

p0042However, it would also be conceivable that the embodiments shown in FIGS. 1a and 1b. Is used exclusively for the feed movement or for the return of the securing element 2. In this case, a respective spring device, which is operatively connected to the securing element 2, should be provided, which serves to generate the feed movement or the return movement and is in each case pretensioned by the counter-movement of the securing element 2, which is driven by the motor device 31.

p0043The feed movement of the securing element 2 results in the formation of a sleeper extending transversely to the seat longitudinal direction X, which extends substantially along the entire width of the seat surface 10 and which is brought into direct contact with the pelvis, which is strongly compressed in this region. The so-called looseness between the basin B and the securing element 2 is reduced by the compressed padding between the securing element 2 and the seat surface 10. The preferably fence element 2, which can be deformed horizontally in the X-direction and vertically stiff, can thus immediately, in the event of a crash, transfer the energy of the occupant introduced via the basin B directly into deformation work. In this way, a uniform, low load on the basin B and other body parts is realized. In addition, the loads of the vehicle seat 1 are thereby also reduced.

p0044The force required for the plastic deformation is designed in such a way that the forward movement of the basin B of a seated person is braked in a crash case on a section controlled by the deformation of the securing element 2 along the seat longitudinal direction X. As a result, the forces acting on the basin B and the spinal column of a seated person in the event of a crash can be reduced. The securing element 2 thus acts as an energy-absorbing element.

p0045FIG. 2a shows a second embodiment of the motor vehicle seat 1 in the same schematic longitudinal sectional view as in FIG. 1a.

p0046In contrast to the first embodiment, this motor vehicle seat 1 has a translatory-movable securing element 2. The substantially longitudinally extending securing element 2, which is arranged essentially perpendicular to the longitudinal section plane, is arranged with its end sections 24 in the two lateral areas of the seat part 12 in guide structures 35, respectively. The guide structures 35 can be designed in the form of a rail.

p0047Just as in the embodiment of the motor vehicle seat 1 described above, three basic variants exist with regard to the design of the drive device 3.

p0048In a first variant, the drive device 3, as shown in FIG. 2 b, has a motor device 31 on each side of the motor vehicle seat, which drives both the feed movement and the return movement of the securing element 2.

p0049In the second variant, the motor device 31 is provided exclusively for the feed movement, wherein the return movement of the securing element 2 is realized by means of a spring device, which is not shown in FIGS. 2a and 2b. The spring device is then preloaded during the feed movement of the securing element 2

p0050In the third variant, the motor device 31 is provided for the return movement of the securing element 2, whereby the feed movement can be realized by means of a spring element, which is not shown in FIGS. 2a and 2b. For this spring element, a holding device is required which can be triggered in the event of a crash. An electromagnet which provides the required linear movement of the securing element 2 together with the guide structures 35 can in particular be used as the motor device 31.

p0051FIGS. 3a to 7b show five further embodiments of the motor vehicle seat which combine the principle of a retractable securing element 2 with a device for tightening the lap belt of a seat belt arranged on the motor vehicle seat.

p0052All the five illustrated embodiments have in common that the drive device 3 comprises at least one strand-shaped pulling means 37. This strand-shaped traction means 37 is in operative connection with the motor device 31, 31 'in such a way that the end portion 44 of a seat belt 4 arranged at the basin B simultaneously tapers toward the seat surface 10 during the feed movement of the securing element 2. In the embodiment shown,

p0053FIG. 3a shows a first exemplary embodiment of a motor vehicle seat 1 according to the invention with an integrated belt tensioning device in a longitudinal sectional view parallel to the seat longitudinal direction X. As in the vehicle seat 1 shown in FIGS. 2a and 2b, a translatively movable securing element 2 is provided. 2, the motor device 31 'is arranged in the region below the backrest part 11 and is operatively connected to the securing element 2 via a first strand-shaped pulling means 37. For this purpose, the strand-shaped traction means 37 is fastened by its one end to the securing element, to the motor device 31 via a deflection means designed as a deflecting roller 39.

p0054In addition, the drive device 3 has a second strand-shaped traction means 37 '. This second strand-shaped traction means 37 'is fastened by its one end to the motor device 31' and by its second end to the end portion 44 of the safety belt 4 which runs on the basin B of a seated person and thus produces the operative connection between the motor device 31 'and the safety belt 4.

p0055In addition, as shown in FIG. 3b, this spring element 31 "is prestressed during the feed movement of the securing element 2, which is driven by the motor device 31 ', in such a way that, as a result of the movement of the securing element 2, The motor device 31 'winds a part of the strand-shaped first traction means 37. At the same time, the motor device 31' winds the second traction-type traction device 37 ' So that the end portion 44 of the seat belt 4 is pulled towards the seat surface 14. In this way, the tightening of the seat belt 4 assists the already described effect of the feed movement of the securing element 2 and thus acts in an uncontrolled preliminary displacement of the berth B of a seated person in a crash Case.

p0056FIGS. 4a and 4b show a second embodiment of a motor vehicle seat 1 according to the invention, which is very similar to the first embodiment of FIGS. 3a and 3b, with an integrated belt tensioner. The only difference is that the motor device 31 'does not realize the feed movement and the belt tensioning by the winding of the strand-shaped pulling means 37 and 37' but by a translational movement of the end sections of the strand-shaped pulling means 37, 37 'assigned to the motor device 31'. For generating the linear movement, in particular a correspondingly designed electromagnet can serve as motor device 31 '.

p0057FIGS. 5 a and 5 b show a third embodiment of a motor vehicle seat according to the invention with an integrated belt tensioner. As in the case of the motor vehicle seat illustrated in FIGS. 1a and 1b, a rotatably movable, bracket-shaped securing element 2 is shown. In addition, the drive device 3 has a spring element 33 for the feed movement of the securing element 2. In the initial position of the securing element 2 shown in FIG. 5 a, the spring element 33 is prestressed against the securing element 2. In a crash case, a holding device (not shown in FIG. 5a) is triggered so that the rotary feed movement of the securing element 2, which is driven by the spring element 33, can take place in the direction of the seat surface 10, as shown in FIG. 5b. The motor device 31 arranged on an articulated end section of the securing element 2 serves to return the rotatably movable securing element.

p0058A strand-shaped pulling means 37 is arranged on the adjustment section 26 of the bow-shaped securing element 2 and is operatively connected by means of deflecting means 39 to the end section 44 of a lap belt 4 such that the rotational feed movement of the securing element 2 inevitably causes a tightening of the lap belt 4 towards the seat surface 10. In the embodiment shown in FIGS. 5 a and 5 b, two deflection means designed as deflecting rollers 39 are arranged below the seat shell 13 essentially along the seat longitudinal direction X.

p00595a and 5b it would also be conceivable to provide as a means for returning the securing element 2 a spring device which is prestressed against the feed movement in the feed movement of the securing element 2, which is driven by the motor device 31. If a spring element is provided for the feed movement or for the return movement, the motor device 31 can also be provided at any point along the strand-shaped pulling means 37, in particular integrated with the deflection means 39.

p0060Starting from the embodiment shown in FIGS. 5a and 5b, a further variant, in which the motor device 31 is provided both for the feed movement and for the return movement of the securing element 2, is shown as a fourth embodiment of the motor vehicle seat 1 according to the invention in FIGS. 6a and 6b .

p0061FIGS. 7 a and 7 b show a fifth embodiment of a force-pulling seat 1 according to the invention with an integrated belt tensioner. This motor vehicle seat 1 has a translatory-movable securing element 2 as described with reference to FIGS. 2 a and 2 b. Otherwise, the construction of the drive device 3 corresponds to a strand-shaped pulling means 37 of the illustration shown in FIGS. 6a and 6b. Therefore, the embodiments made for the mentioned figures apply correspondingly to the embodiment shown in FIGS. 7a and 7b.

p0062FIG. 8 shows a schematic perspective view of a bracket-shaped securing element 2 which can be used for the embodiments of the motor vehicle seat 1 according to the invention shown in FIGS. 1 a and 1 b or 5 a to 6 b.

p0063Between the two end sections 24, 24 'of the bracket-shaped securing element 2, a rectilinear adjustment section 26 extends in the form of a pivot section. The two end sections 24, 24 'are angled away from the adjustment section 26 in such a way that they form a pivot axis. The securing element 2 can thus be pivotally pivoted at the end sections 24, 24 'in a simple manner so that the adjustment section 26 in the seat part 12 of a motor vehicle seat 1 can be moved in the direction of the seat surface 10.

p0064In the region of the one end section 24, a motor device 31 with a gear 34 is arranged to transmit a torque to the securing element 2 and to pivot about the pivot axis. The transmission 34 is also in operative connection with a barrier 32, which prevents a return movement of the securing element 2 during the feed movement. The active connection of the barrier 32 with the gear 34 can be released as required in order to return the securing element 2, for example, by the motor device 31 or by a spring element (not shown in FIG. 8) into the initial position.

p0065Five exemplary embodiments for a specific embodiment of the securing element 2 and the associated drive device 3, which are each arranged on a seat part 12 comprising a seat shell 13, are described below with reference to FIGS. 9 a to 13 b.

p00669a and 9b, a drive motor 31 is arranged centrally between the two longitudinal sides 12a, 12b of the seat part 12, which is extended in the seat longitudinal direction X, of the seat part 12, a motor shaft 310 perpendicular to the longitudinal axis of the vehicle running towards both longitudinal sides 12a, 12b X and is provided at its end with a gear wheel 311 and 312, respectively. Each of these toothed wheels 311, 312, which can be driven by the drive motor 31, engages with the toothing of an associated toothed rack 211, 212 which extends parallel to a longitudinal side 12a, 12b of the seat part 12 in the seat longitudinal direction X. A tube forming the adjustment section 26 of the securing element 2 is accommodated at one end of the two toothed rods 211, 212 and can be adjusted along the longitudinal axis X of the vehicle by means of the toothed rods 211, 212, as indicated by the double arrow in FIG. 9b. Depending on the direction of rotation of the drive motor 31, on the one hand a displacement of the securing element 2 out of an initial position is possible in order to counteract the forward displacement of the basin of a person sitting on the corresponding vehicle seat, or alternatively a return of the securing element 2 into the initial position.

p0067In FIGS. 9a and 9b, the securing element 2 is shown in its crash-conditionally advanced state, from which it can be returned to the initial position by actuation of the drive motor 3.

p0068FIG. 10 shows a securing element 2 and an associated drive device 3 with a driving motor 31 to be arranged centrally, without the associated seat part. As in the exemplary embodiment explained with reference to FIGS. 9a and 9b, a drive shaft 310 'runs off from the drive motor 31 in two opposite directions, but the sections of the drive shaft 310' lying outside the motor housing are provided with an external thread. A bushing 313, 314, which is provided with an internal thread, is provided on each of the drive shaft 10, which is provided with an external thread, on both sides of the drive motor 31, which bushes are mounted on the drive shaft 310 'in a rotationally fixed but longitudinally displaceable manner. On each of the bushes 313, 314, a connecting rod 213 or 214 is pivotally pivoted at an articulation point 213a, 214a such that the connecting rods 213, 214 can rotate freely about their respective articulation axis 213a, 214a in their common plane. The two connecting rods 213, 214 extend towards the adjusting section 26 of the securing element 2, which is formed by a transverse rod, and engage with it via pins 213b, 214b, which engage in a longitudinal guide (elongated hole) 263, 264, respectively. The front adjusting section 26 of the securing element 2 is additionally guided in an elongated guide element 360 projecting longitudinally from the housing of the drive motor 31.

p0069FIG. 10 shows the front adjusting section 26 of the securing element 2 after a translational movement (along the direction of the double arrow in FIG. 10) away from the drive motor 31 (feed movement) into a crash-related pre-displaced position, Corresponding motor vehicle. By actuation of the drive motor 31 (with a reversal of the direction of rotation of the motor relative to the preceding forward displacement of the front adjusting section 26 of the securing element 2), the securing element 2 can be returned to the initial position shown in dashed lines in FIG. The transmission of the displacement force of the drive motor 31 on the front V preparing portion 26 of the fuse element 2 is realized via the longitudinally displaceable manner on the drive shaft 310 'mounted sockets 313, 314, soft inwardly in the direction of the drive motor 31 move, and hinged about the hereto gelenkbar Connecting rods 213, 214. For the defined longitudinal guidance of the front adjusting section 26 of the securing element 2, the longitudinally extending guide element 360 protruding from the housing of the drive motor 31 is used.

p007011a and 11b, the relevant adjusting section 26 of the securing element 2 can be displaced about a rotational axis D by pivoting, wherein the tube-shaped adjusting section 26 of the securing element 2 is braced on the axis of rotation D via a connecting tube 20. In the embodiment shown in FIG. For pivoting the adjusting section 26 of the securing element 2, a drive motor 31 is arranged centrally between the longitudinal sides 12a, 12b of the seat part 12, the motor shaft of which drives a gear 317 via a toothed belt 316 which is connected to the connecting tube 20 of the securing element 2, Actuation of the drive motor 31, the securing element 2 is pivoted. As an alternative to the toothed belt, the power transmission from the drive motor 31 can be effected, for example, by means of a warp or V-belt.

p007111a and 11b show the securing element 2 in a state in which its displacement section 26 has been displaced by pivoting into a position in which it is intended to prevent the slipping of the tank of a vehicle occupant in a crash case under the lap belt. From this position, the securing element 2 can be returned by its actuation of the drive motor 31 of the drive device 3 with a corresponding direction of rotation in its initial position, whereby the connecting tube 20 of the securing element 2 is guided in a longitudinal slot 120 of the seat part 12 and the adjustment section 26, in its initial position, An associated transverse slot 126 of the seat part 12.

p0072In the exemplary embodiment illustrated in FIG. 12 without the associated drive motor, the relevant adjusting section 26 of the securing element 2 is moved by a traction means 38 extending centrally between the two longitudinal sides 12a, 12b of the seat part 12, the adjusting section 26 of the securing element 2 being provided with lateral guide elements 266, 267 Is guided on a respective guide rail 216 or 217, respectively, which extends along one of the longitudinal sides 12a, 12b.

p0073FIG. 12 shows the securing element 2 in its starting position, from which it can be moved out of the seat longitudinal direction (along the double arrow shown in the figure) by means of an infeed movement into a displaced position in which it slides against the slipping of the basin of a vehicle occupant The lap belt.

p0074With regard to the design of the traction means 38, different variants are conceivable. In the case of a circulating traction means, for example in which the two free ends of a traction means are respectively connected to the securing element 2, the traction means is returned by the reversing of the direction of rotation of the drive motor relative to the preceding forward displacement of the traction motor Pulling means. In the case of an elongated traction means 38 which, as shown in FIG. 12, is fastened on the one hand to the relevant adjusting section 26 of the securing element 2 and with the other end to a suitable part of the drive motor (not shown), the restoring movement can be effected, for example, by means of a spring arrangement. Alternatively, such a pulling means 38 can also be arranged in such a way that the forward movement of the securing element 2 occurs in a crash case by means of a spring arrangement, and the restoring movement is performed by the traction means coupled to the drive motor.

p007513a and 13b, the relevant front adjustment section 26 of the securing element 2, which extends between the two longitudinal sides 12a, 12b of the seat part 12 transversely to the seat longitudinal direction X, has a respective spindle nut 268, 269 at its two outer ends Which is mounted so as to be non-rotatable and longitudinally displaceable on a threaded spindle 318, 319 extending in the longitudinal direction X of the seat. The two threaded spindles 318, 319 extend in each case along one of the two longitudinal sides 12a, 12b of the seat part 12 and are mounted on the seat shell 13. By actuating a drive motor (not shown in FIGS. 13a and 13b), which is assigned to the threaded spindles 318, 319 and produces a rotational movement of the threaded spindles 318, 319, a longitudinal movement of the spindle nuts 268, 269 arranged thereon, and thus the adjusting section 26 of the securing element 2, . This can then be moved forward out of the initial position illustrated in FIGS. 13a and 13b into a position in which it prevents the slipping of a vehicle occupant. The displacement of the adjusting section 26 into the initial position then takes place by reversing the direction of rotation of the drive motor and thus also of the threaded spindles 318, 319.

p0076In this case, a separate drive motor can optionally be assigned to each gear blade 318, 319, or a common motor is used which is coupled to the respective threaded spindle 318, 319 via suitable gear elements (for example via a toothed belt).