Safety device for a vehicle seat

Abstract

The invention relates to a safety device (5) with an airbag device (6) which can be integrated into a side structure of a vehicle seat (1) and a belt device (7) which can be integrated into the vehicle seat (1), wherein the airbag device (6) has an inflatable airbag (10), and the belt device (7) has a belt (15), a belt tensioner (16) and a tensioning means (9) connecting the belt (15) to the belt tensioner (16), wherein the belt tensioner (16) has a drive wheel (8) which can be driven to perform a rotary movement when the belt tensioner (16) is activated and to which the traction means (9) is connected, wherein the drive wheel (8) has a first force-transmission contour with a plurality of depressions and / or elevations arranged distributed in the circumferential direction, and the traction means (9) has a second force- transmission contour (18) corresponding in shape to the shape of the first force-transmission contour, and the drive wheel (8) and the traction means (9) engage in one another by a positive force-transmitting connection of the first and second force-transmitting contours (18), wherein the drive wheel (8) transmits the rotary movement into a linear tensioning movement of the tensioning means (9) when the belt tensioner (16) is activated.

Description

[0001] Safety device for a vehicle seat

[0002] The present invention relates to a safety device for a vehicle seat with the features of the preamble of claim 1 and a vehicle seat with the features of the preamble of claim 7.

[0003] Safety devices of the generic type comprise at least one airbag device integrated in a side structure of a vehicle seat and a belt device with a belt which is tightened when the safety device is activated and, in the tightened position, holds an airbag inflated by the airbag device in position. Furthermore, a gas generator is provided which, when activated, abruptly generates a gas flow to inflate the airbag, which simultaneously serves to drive a belt tensioner associated with the belt of the belt device.

[0004] Such a safety device is known, for example, from the publication DE 10 2022 110946 B3 and is also referred to as a seat cushion restraint system (SCRS). The belt device provided there comprises a belt tensioner with a drive wheel designed as a gas turbine with turbine blades and a winding shaft connected to the drive wheel of the gas turbine in a rotationally fixed manner, to which a traction means connected to the belt is attached. When the safety device is activated, the gas generator suddenly releases a very large volume flow of gas, which inflates the airbag and is simultaneously directed onto the drive wheel of the gas turbine in the belt tensioner, so that the drive wheel is driven to rotate. Due to the winding shaft, which is non-rotatably connected to the drive wheel, it is thus abruptly driven in the winding direction of the traction means when the safety device and the gas generator are activated, so that the belt of the belt device connected to the traction means is tightened accordingly. The traction means is connected to the winding shaft in a tension-proof manner and is thus wound up into a coil on the winding shaft when the safety device is activated. The solution known there thus requires an installation space which is at least present in the vehicle seat and which is defined by the winding shaft and the outer diameter of the winding of the traction means to be wound thereon.

[0005] The object of the invention is to provide a safety device of the generic type with a belt tensioner with improved force transmission to the traction means and a reduced installation space requirement.

[0006] To solve the problem, a safety device with the features of claim 1 and a vehicle seat with the features of claim 7 are proposed. Further preferred embodiments of the invention can be found in the sub-claims, the figures and the associated description.

[0007] In accordance with the basic idea of the invention, it is proposed that the drive wheel has a first force transmission contour with a plurality of depressions and / or elevations distributed in the circumferential direction and the traction means has a second force transmission contour corresponding in shape to the shape of the first force transmission contour, and the drive wheel and the traction means engage with one another by means of a positive forcetransmiting connection of the first and second force-transmiting contours, the drive wheel transmiting the rotary movement into a linear tightening movement of the traction means when the belt tensioner is activated.

[0008] With the proposed solution, the force is transmited by means of a positive connection between the traction means and the drive wheel in a local, stationary force transmission zone in the area of the overrun zone of the traction means on the drive wheel, so that the force transmission does not otherwise require a fixed connection between the traction means and the drive wheel. This means that the traction means no longer needs to be fixed and wound onto the drive wheel in a tension-proof manner and can instead be routed further from the power transmission zone as required. It is possible to wind up the traction means or to lead it away from the drive wheel, as the part of the traction means that has passed the drive wheel makes no further contribution to the transmission of the tensioning movement. The belt tensioner can thus be made considerably more compact, at least in the area of the drive wheel, as the tensioning means only has to rest against the drive wheel in the force transmission zone.

[0009] It is also proposed that the traction means is flexible in itself. Due to the flexible design of the traction means, it can adapt better to the outer shape of the drive wheel in the area of the power transmission zone, so that the power-transmiting engagement of the traction means with the drive wheel can be improved. Furthermore, with the section that has just passed the drive wheel, the traction means exerts no or a considerably lower counterforce that counteracts the tightening movement when it encounters obstacles, as it can deform itself when it encounters corresponding obstacles. Furthermore, after passing the drive wheel, the traction means can be guided away in any desired curvature, so that it can adapt beter to existing installation spaces. As the traction means is only exposed to tensile forces during power transmission, apart from the small lateral forces caused by the engagement of the toothing, the proposed flexibility is not a disadvantage. Possible flexible traction means include, for example, a flexible plastic, elastomer or metal strip with a second power transmission contour, e.g. in the form of toothing or a regular structure of recesses or cutouts, link chains with a chain structure corresponding to the shape of the first power transmission contour of the drive wheel or the like.

[0010] It is further proposed that a catching volume is provided on the belt tensioner in relation to the tensioning movement of the traction means upstream to accommodate the traction element. The catching volume can be formed by a corresponding container or also by a free space deliberately provided on the belt tensioner in the vehicle seat or on the belt tensioner, into which the traction element is discharged. For this purpose, the catching volume is designed in the size of the volume and the arrangement of the volume in such a way that it enables a correspondingly controlled removal and reception of the traction means.

[0011] It is also proposed that a gas generator is provided which, when activated, abruptly releases a gas flow to inflate the airbag and drive the belt tensioner. The airbag and the belt tensioner are thus activated at the same time and supplied with a gas flow by a single gas generator in a compact design, whereby a time delay in the activation or the activation process of the airbag and the belt tensioner can be deliberately brought about by a corresponding design of the flow paths.

[0012] It is further proposed that the belt pretensioner has a mass body drive with a mass body chain which, when the belt pretensioner is activated, can be driven to perform a drive movement during which they engage positively with an outer contour of a second drive wheel connected to the drive wheel in a rotationally fixed manner. The proposed drive has the advantage that it enables a particularly long tensioning movement defined by the length of the mass body chain, whereby the mass body chain can be stored in a tube with any desired course, which can be specially adapted in its shape to the available installation space ratios.

[0013] It is also proposed that the belt tensioner has a backstop that acts against the rotational movement of the drive wheel during the tensioning movement. This means that the tensioning means and thus also the belt is locked against a return movement after the tightening movement has taken place, the belt is practically held in the tightened position and thus supports the airbag in the predetermined position.

[0014] To solve the problem, a vehicle seat with two safety devices according to one of claims 1 to 6 with two identical airbag devices and two identical belt devices is also proposed, wherein the airbag devices and the belt devices are arranged symmetrically to a central axis on two opposite side structures of the vehicle seat. With the proposed solution, the occupant siting on the vehicle seat is restrained on both sides, i.e. is laterally protected in both directions with respect to a direction of impact.

[0015] The invention is explained below with reference to preferred embodiments with reference to the atached figures. It shows Fig. 1 shows a vehicle seat with a safety device according to a first and a second embodiment before and after activation; and

[0016] Fig. 2 shows an enlarged view of the vehicle seat of Fig. 1; and

[0017] Fig. 3 an enlarged representation of a drive wheel of the safety device with a belt tensioner according to the first and second embodiments; and

[0018] Fig. 4 a vehicle seat with a safety device according to a third embodiment before and after activation; and

[0019] Fig. 5 an enlarged view of the vehicle seat of Fig. 4; and

[0020] Fig. 6 an enlarged view of a drive wheel of the safety device with a belt tensioner according to the third embodiment; and

[0021] Fig. 7 a drive wheel with a belt tensioner with a mass body chain; and

[0022] Fig. 8 a seat cushion of a vehicle seat according to the invention with two safety devices before activation; and

[0023] Fig. 9 a seat cushion of a vehicle seat according to the invention with two safety devices after activation. In Figure 1, a vehicle seat 1 with a seat cushion 3, a backrest 2 pivotably connected to the seat cushion 3 via a joint 14 and a headrest 4 arranged on the upper side of the backrest 2 can be seen in the left-hand representation, whereby the same vehicle seat 1 can be seen in the upper representation of Figure 2 in an enlarged section of the seat cushion 3 and the backrest 2. In the vehicle seat 1, a safety device 5 according to the invention can be seen with an airbag device 7 arranged in a lateral section of the backrest 2 and a belt device 7 before activation.

[0024] The belt device 7 comprises a belt 15, which is fastened with a first end in an upper section of the backrest 2, whereby it can be fastened separately to the backrest 2 via corresponding fastening means or also via the airbag device 6. The belt 15 is laid in such a way that it extends further downwards through the backrest 2 to the joint 14 and from there further through a lateral section of the seat cushion 3 to a deflection device 11 arranged at the front of the seat cushion 3. The belt 15 is deflected at the deflection device 11 and connected at its second end to a tension means 9 in a tension-proof manner. The traction means 9 has a second force transmission contour in the form of a toothing 17, with which it engages in a shape-corresponding second force transmission contour 18 of a drive wheel 8 and, above this, is in a positive connection of a force transmission zone with the drive wheel 8 in the region of the contact zone of the traction means 9 on the drive wheel 8.

[0025] The drive wheel 8 is in a rotationally fixed connection with a second drive wheel 13 of a belt tensioner 16, which can be seen in Figure 3 and which drives the drive wheel 8 in a rotary movement when it is activated. The rotary movement of the drive wheel 8 is transmitted into a linear traction movement of the traction means 9 by the positive engagement of the toothing 17 of the traction means 9 in the first force transmission contour 18 of the drive wheel 8. This pulling movement of the pulling means 9 is then in turn transmitted to the second end of the belt 15 in order to tighten the belt 15, so that the belt 15 assumes the position shown in the middle illustration of Figures 1 and 2 after activation of the belt tensioner 16 or the belt device 7. The first force transmission contour 18 on the drive wheel 8 is designed to correspond in shape to the toothing 17 of the traction means 9, which in the simplest case can be realized by this also being designed as toothing. Alternatively, it is also sufficient if the drive wheel 8 has a first force transmission contour in the form of regularly arranged recesses, in which the traction means 9 engages with the points of the toothing 17. Furthermore, the traction means 9 can also have a second force transmission contour in the form of regularly arranged recesses, e.g. in a ladder structure, whereby the first force transmission contour 18 on the drive wheel 8 can then also be designed as a type of toothing, which engages with the tips in the recesses of the ladder structure for force transmission in the force transmission zone. The first and second force transmission contours are designed to correspond in shape, for example in that one of the force transmission contours is designed as a positive shape and the other force transmission contour is designed as a negative shape. It is not necessary for the force transmission contours to be in full contact with each other, it is sufficient if they are in positive contact with each other in the circumferential direction and thus transmit the tensile force. In this case, the first force transmission contour on the drive wheel 8 is arranged over its entire circumference on the radially outer lateral surface of the drive wheel 8 and the second force transmission contour over the entire length of the section of the traction means 9 with which the traction means 9 passes the drive wheel 8 during the tightening movement, so that the force-transmiting connection is not interrupted during the tightening movement of the belt 15.

[0026] The airbag device 6 comprises an inflatable airbag 10 which, when the airbag device 6 is activated, is deployed to the inflated geometry shown in the middle illustrations of Figures 1 and 2. The airbag device 6 is arranged in a laterally arranged section of the backrest 2, and the airbag 10 is inflated from the airbag device 6 when activated from the backrest 2 in the direction of the seat cushion 3.

[0027] The geometry of the belt 15 and the airbag 10 in the tightened or deployed position after tightening and deployment are matched to each other in such a way that the belt 15 supports the airbag 10 laterally and thus holds it in position. This supporting and holding in position of the air-bag 10 can be further supported by the belt 15 being connected to the airbag 10, for example by a stitching or guide openings. In the first embodiment example, the traction means 9 is designed as a dimensionally stable rod and is thus displaced backwards out of the seat cushion 3 past the drive wheel 8 when it is activated.

[0028] In the second embodiment example shown in the right-hand illustration of Figure 1 and the lower illustration of Figure 2, the traction means 9 is designed to be flexible so that, after passing the drive wheel, it can be received by multiple deformations in any direction in a collection volume 19 of the belt tensioner 16 or the seat cushion 3 provided for this purpose without exiting the seat cushion 3.

[0029] Since the traction means 9 is only subjected to traction when the belt tensioner 16 is activated in the section between the drive wheel 8 and the second end of the belt 15, its flexibility is not a disadvantage for the transmission of force. The flexibility is even advantageous, since the traction means 9 can thus adapt better to the first power transmission contour 18 of the drive wheel 8. Furthermore, this makes it easier to fold the traction means 9 into the collection volume 19. Due to the positive engagement in the first force transmission contour 18 and the ideally localized punctual force transmission in this area, the tensioning means 9 is only subjected to tension in the section between the drive wheel 8 and the second end of the belt 15, while the section of the tensioning means 9 that has already passed the force transmission point of the drive wheel 8 is no longer subjected to tension.

[0030] Figure 3 shows the belt tensioner 16 according to a first embodiment. The belt tensioner 16 has a second drive wheel 13, which is designed here as a turbine wheel with radial blades. Furthermore, a gas generator 12 is provided which, when activated, abruptly releases a gas flow which drives the turbine wheel or the second drive wheel 13 to rotate. The second drive wheel 13 is non-rotatably connected to the drive wheel 8, so that the drive wheel 8 is also driven to perform the rotary motion described at the beginning. At the same time, the gas flow generated by the gas generator 12 can also be used to inflate the airbag 10, whereby the flow connections can be established by suitable gas lances or gas lines. Figures 4 and 5 show the vehicle seat 1 with a safety device 5 according to a third embodiment example. The safety device 5 of the third embodiment differs from the first two embodiments in that the traction means 9 is wound onto the drive wheel 8. For this purpose, the end of the traction means 9 is attached to the drive wheel 8 via a fastening means 24, as can be seen in Figure 6. The force is transmitted in an identical manner via a second force transmission contour formed by a toothing 17 on the traction means 9 and a first force transmission contour 18 on the drive wheel 8. The traction means 9 is wound onto the drive wheel 8 in several coils wound next to each other and therefore no longer needs to be subsequently removed.

[0031] Figure 7 shows an alternative embodiment of a belt tensioner 16 with a drive in the form of a mass body chain 20 consisting of a large number of individual balls guided in a tube 25. The second drive wheel 13 here has an outer contour 27 with a plurality of regularly arranged spherical recesses, the shape of which is adapted to the outer shape of the individual balls and which enable a positive force transmission from the individual balls of the mass body chain 20 to the second drive wheel 13 due to the engagement of the individual balls. Furthermore, a collecting container 26 is provided, into which the individual balls are collected after passing the second drive wheel 13. Furthermore, a return lock 21 is provided, which is connected to the drive wheel 8 and above it also to the second drive wheel 13, so that the drive wheel 8 and the second drive wheel 13 are blocked against reverse rotation after a tightening movement has taken place. The drive wheel 8, the second drive wheel 13 and the backstop 21 are shown one above the other for ease of recognition, but in the implementation they are of course arranged and connected coaxially and in a slewing ring and must be imagined one behind the other in the illustration.

[0032] Figures 8 and 9 show a vehicle seat 1 according to the invention as seen from above on the seat cushion 3 before and after activation of two safety devices 5 provided therein. The safety devices 5 are arranged symmetrically to a central axis running in the longitudinal direction of the seat cushion 3. The drive wheels 8 of the safety devices 5 are arranged in pairs next to each other in a front section approximately in the middle of the seat cushion 3 and can thus be driven by a single belt tensioner 16 or by two separate belt tensioners 16. The belt tensioner 16 and the backstop 21 are shown separately from the drive wheels 8 to make them easier to recognize, but in the implementation they are structurally connected to the drive wheel 8, whereby appropriate gears or fixed connections can be provided for the connection. The airbag devices 6 are not shown and must be imagined in a backrest 2 running towards the viewer of the illustrations. The safety devices 5 each have a belt device 7 with a belt 15, which are each connected to the drive wheels 8 via a traction means 9. The belts are each arranged on opposing side structures 22 and 23 of the seat cushion 3 so that, when activated, they support an inflated air-bag 10 on the outside of both sides of the seat cushion 3. The occupant is thus supported on both sides by inflated and supported airbags

[0033] 10.

[0034] List of reference symbols

[0035] 1 Vehicle seat

[0036] 2 Backrest

[0037] 3 Seat cushion

[0038] 4 Head restraint

[0039] 5 Safety device

[0040] 6 Airbag device

[0041] 7 Seat belt device

[0042] 8 Drive wheel

[0043] 9 Traction device

[0044] 10 Airbag

[0045] 11 Deflection device

[0046] 12 Gas generator

[0047] 13 Second drive wheel

[0048] 14 Hinge

[0049] 15 Belt

[0050] 16 Belt tensioner

[0051] 17 Toothing

[0052] 18 Second Power transmission contour

[0053] 19 Catch volume

[0054] 20 Mass body chain

[0055] 21 Backstop Side structure Side structure Fastening element Tube Collecting container Outer contour

Claims

Claims:

1. Safety device (5) with-an airbag device (6) which can be integrated into a side structure of a vehicle seat (1) and a belt device (7) which can be integrated into the vehicle seat (1), wherein-the airbag device (6) has an inflatable airbag (10), and-the belt device (7) has a belt (15), a belt tensioner (16) and a tensioning means (9) connecting the belt (15) to the belt tensioner (16), wherein-the belt tensioner (16) has a drive wheel (8) which can be driven to perform a rotary movement when the belt tensioner (16) is activated and to which the traction means (9) is connected, characterized in that-the drive wheel (8) has a first force-transmission contour with a plurality of depressions and / or elevations arranged distributed in the circumferential direction, and the traction means (9) has a second force-transmission contour (18) corresponding in shape to the shape of the first force-transmission contour, and-the drive wheel (8) and the traction means (9) engage in one another by a positive forcetransmiting connection of the first and second force-transmiting contours (18), wherein-the drive wheel (8) transmits the rotary movement into a linear tensioning movement of the tensioning means (9) when the belt tensioner (16) is activated.

2. Safety device (5) according to claim 1, characterized in that-the traction means (9) is flexible in itself.

3. Safety device (5) according to one of claims 1 or 2, characterized in that-a collecting volume (19) is provided on the belt tensioner (16) upstream in relation to the tensioning movement of the tensioning means (9) for receiving the tensioning means (9).

4. Safety device (5) according to one of claims 1 to 3, characterized in that-a gas generator (12) is provided which, when activated, abruptly releases a gas flow for inflating the airbag (10) and for driving the belt tensioner (16).

5. Safety device (5) according to one of claims 1 to 4, characterized in that-the belt tensioner (16) has a mass body drive with a mass body chain (20) which, when the belt tensioner (16) is activated, can be driven to perform a drive movement during which it engages positively with an outer contour (27) of a second drive wheel (13) connected to the drive wheel (8) in a rotationally fixed manner.

6. Safety device (5) according to one of claims 1 to 5, characterized in that-the belt tensioner (16) has a backstop (21) acting against the rotational movement of the drive wheel (8).

7. Vehicle seat (1), characterized in that-two safety devices (5) according to one of claims 1 to 6 are provided with two identical airbag devices (6) and two identical belt devices (7), the airbag devices (6) and the belt devices (7) being arranged symmetrically to a central axis on two opposite side structures (22, 23) of the vehicle seat (1).

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