WO2006089670A2

WO2006089670A2 - Airbag retainer system

Info

Publication number: WO2006089670A2
Application number: PCT/EP2006/001386
Authority: WO
Inventors: Walter Eberle; Christian Götz; Till Heinrich; Simon Kramer; Albert Reitinger; Julien Richert
Original assignee: Daimlerchrysler Ag
Priority date: 2005-02-25
Filing date: 2006-02-16
Publication date: 2006-08-31
Also published as: WO2006089670A3; JP2008531364A; DE102005048912A1

Abstract

The invention relates to an airbag retainer system (1) with an airbag (3), a gas generator (2) and an airbag limiter device, limiting the maximum unfurling extent of the airbag (3), dependent on parameters relevant to passenger occupancy and permits a reliable unfurling of the airbag (3), whereby a storage device is provided for the retainer strap limiting the unfurling path of the airbag (3) and the same is provided outside the airbag (3).

Description

DaimlerChrysler AG

Airbag restraint system

The invention relates to an airbag restraint system according to the preamble of patent claim 1.

In modern vehicle construction increasingly restraint systems are used, which are adapted in the event of an accident or an accident on the in-vehicle occupants. For this purpose, occupant-relevant parameters are first recorded and subsequently evaluated or passed on to the restraint systems. In this way it is ensured that the restraint systems are optimally adjusted according to the respective situation, whereby the protection of vehicle occupants is increased.

From DE 298 05 217 Ul, for example, a device is known with which the shape of a gas bag and in particular the unfolding distance in the unfolded state can be influenced. For this purpose, arranged in the airbag tethers are provided whose length is varied by a sensor-controlled AufwiekelVorrichtung. In the case of restraint, the position of the vehicle occupant is detected by a sensor and the length of the tethers is limited accordingly. To limit the length of the tethers arranged in the airbag take-up devices are provided. From DE 100 20 795 Al it is known, depending on the position of the gas bag restraint system associated vehicle seat, to change the length of the located in the gas bag portion of a tether.

Against the background of this prior art, the invention has for its object to provide an airbag restraint system in which the deployment path of the airbag is limited, which allows reliable deployment to the predetermined deployment position of the airbag.

This object is achieved by an airbag restraint system having the features of patent claim 1.

Accordingly, the gas bag restraint system according to the invention with an airbag and a gas generator is distinguished by an airbag limiting device which limits the maximum deployment path of the airbag as a function of occupant-relevant parameters. The airbag limiting device has a storage device for at least one limiting band of the airbag limiting tether, wherein the storage device is arranged outside of the airbag. If in the context of the invention of deployment path is mentioned, so is the distance from the vehicle elements in which the airbag is arranged to the ideal impact point of an occupant on the unfolded airbag meant. The occupancy parameters are all parameters which have an influence on the occupant's load in the event of an accident. Examples include the weight of the occupant, the speed of the vehicle before or during the impact, the size of the occupant and the position of the occupant on his vehicle seat. According to the invention, a tether is provided whose length has a direct influence on the deployment path of the gas bag. In order to ensure a safe deployment of the gas bag regardless of the length of the tether, a storage device for the tether is provided. The storage device is designed so that it reliably provides a certain length of tether at all times. The storage device is arranged outside the gas bag. This means that the storage device is not arranged in the gas bag but in the vicinity of the gas bag. The arrangement of the storage device, which is independent of the gas bag, ensures that the gas bag can reliably deploy independently of the storage device of the tether at each set length of the tether. Thus, the invention can also be used independently of any gas bag form or airbag deployment.

Advantageous embodiments can be found in the dependent claims.

An easy way to ensure control of the Ðntfaltungsstrecke of Gassaσks depending on occupant load relevant parameters is to set the maximum deployment path of the airbag in dependence on the position of the restraint system associated vehicle seat. In such a control, it is believed that a small, light person places the vehicle seat further forward relative to the steering wheel, and a large, heavy person places the vehicle seat further to the rear. Thus, only the position of the vehicle seat provides information that represents occupant load relevant parameters. This design is particularly advantageous because of the position the vehicle seat particularly easy to capture and transferred to the airbag-limiting device. It is also conceivable to determine the maximum deployment path of the gas bag by a linear, a non-linear or a limited linear function of the position of the restraint system associated vehicle seat.

For example, limiting the airbag sizing may result from a seated position that is greater or less than a seated position for riding or comfortable sitting. This is for example given in two-door vehicles when the seat is adjusted for easy boarding. Another limitation may result from technical feasibility, for example, space reasons. This limitation is then mainly in the edge region of the seat adjustment and the setting of

Limiting device provided. It is also conceivable to provide a limitation in the middle. This then has the effect that when the seat is arranged in the region of middle seating positions, no variation on the gas bag restraint system is made.

It is conceivable to mechanically connect the position of the vehicle seat with the airbag limiting device. A mechanical coupling between the vehicle seat and gas bag boundary means represents a particularly reliable and störunanfällige coupling. In this way, it is always ensured that the gas bag limiting device adjusts the maximum deployment path of the gas bag in dependence on the position of the vehicle seat and an optimal adaptation of the Gas bag restraint system is ensured. Of course, it is also conceivable to carry out the coupling between the position of the vehicle seat and the airbag-limiting device electrically. To Sensors are required to detect the position of the vehicle seat. Furthermore, an evaluation unit and an actuator connected to the evaluation unit is necessary, which sets the maximum deployment path of the gas bag via the gas bag boundary device. The actuator may be, for example, an electric drive. It is just as conceivable to use other widely used drives, such as hydraulic drives.

As a mechanical coupling, a Bowden cable can be provided. When a Bowden cable is a structurally simple component, which also still works reliably after many load changes. A Bowden cable is a proven in the automotive sector, often used and therefore cost-effective component.

As storage device for the tether, a winding shaft may be provided. It is conceivable to connect the one end of the tethers with the airbag and to connect the other end of the tethers with the winding shaft and roll up on this. The tethers can be arranged both inside and outside the airbag. Of course, both arrangements are conceivable. The position of the winding shaft thereby directly influences the length of the tether available in the case of an unfolding gas bag. It is conceivable to unwind the tether when changing the position of the winding shaft. It is also conceivable to produce only a tether on the winding shaft, to block the winding shaft and to provide the lots when deploying the airbag available. A particularly space-saving solution is given when the winding shaft is arranged in a housing of the gas generator. It is conceivable, for example, to store the winding shaft rotatably mounted on the gas generator. This solution is particularly space-saving, since no additional space is required for the gas bag boundary device. In addition, the straps stored on the winding shaft are available in the immediate vicinity of the gas bag and can be removed directly from the storage device when the gas bag is deployed. The tether is where it is needed, so that always a safe deployment is guaranteed.

The winding shaft may be connected directly or indirectly with the Bowden cable. The winding shaft can serve as storage device for at least a portion of the Bowden cable. Between the foremost position of a vehicle seat and the rearmost position of a vehicle seat can be up to 30 cm difference. These 30 cm are therefore also available with the Bowden cable as a control variable. Due to the limited space requirement within the gas bag module or in the vicinity of an airbag module brings the possibility to wind the Bowden cable on the winding shaft, a considerable space advantage. Depending on how much Bowden cable is wound on the winding shaft, the winding shaft takes a changed angular position relative to the fixed gas generator. The winding shaft is then fixed over the Bowden cable. This means that each seating position is assigned a specific angular position of the winding shaft. About the changed angular position, the Fangbandlose can be adjusted, ie the length of the tether, which is available in the event of deployment of the airbag. Here, the relationship between Bowden cable and tether be coupled via the winding shaft such that the more Bowden cable is wound on the winding shaft -Sitz takes a front position the less tether is available. With a rear seat position where there is less to no Bowden cable on the winding shaft, there is more tether available. The more tether is available, the greater the deployment distance of the gas bag.

It is conceivable to stockpile several tethers on a winding shaft. Thus, the length of several tethers can be changed by changing the position of a winding shaft. If the winding shaft in the storage areas for the individual tethers has different diameters, different lengths of the tethers can be adjusted depending on the position of the vehicle seat. Thus, the length of several tethers can also be set differently via an airbag limiting device.

Another aspect of the invention lies in the particular embodiment of the winding shaft for the storage of the tethers and the Bowden cables. In order to prevent an adjustment of the tether length occurs at each seat adjustment, it is proposed that the winding shaft is composed of several sub-shafts.

When the sub-shafts are provided with internal threads which engage with a threaded sleeve arranged on the gas generator, a rotation of the sub-shaft always causes an axial displacement on the gas generator. This has the effect that one of the partial waves can be used as a stop for the rotational movement of another partial wave. In order to avoid voltage peaks, a damping device can be provided between two adjacent partial waves.

In order not to hinder the gas outlet of the gas generator, the threaded sleeve may be provided with openings which are in register with the gas outlet openings of the gas generator.

Of particular importance is a fail-safe, which causes an automatic alignment of the winding shaft, if the Bowden cable adjustment is not possible.

One way of fail-safe may be a locking of the part shaft, which stores the Bowden cable.

Alternatively, the fail-safe can be formed by two opposing coil springs, which always sets the partial wave with the Bowden cables in a 50% position.

In the following the invention will be explained in more detail with reference to the embodiments illustrated in the drawings.

Showing:

1a is a schematic representation of the gas bag restraint system according to the invention with a vehicle seat associated therewith, which occupies a front seat position;

Fig. Ib is a schematic representation of the gas bag restraint system according to the invention with a vehicle seat assigned thereto, which occupies a rear seat position;

2 is a three-dimensional, partially sectioned view of a gas generator for an inventive gas bag restraint system,

3 is a sectional view of a gas generator along its longitudinal axis for an inventive gas bag restraint system,

4 is a three-dimensional view, which is partially cut, of a winding shaft for a gas generator of a gas bag restraint system according to the invention,

5a, 5b, a portion of a winding shaft according to Figure 4,

6 is a perspective view of a gas generator with a split winding shaft,

7 is a front, side and top view of the gas generator of FIG. 6,

8 is a perspective view of a gas generator with reverse rotation,

9 is a front view and sectional view of a gas generator with a multi-rotatable winding shaft,

10 is a perspective view of a gas generator with gas-permeable partial wave, 11 is a front, side and plan view of the representation of FIG. 10,

12 is a perspective view of a gas generator with different translation stages,

13 is a perspective view of a gas generator with different translation stages in a second embodiment,

14 is a side view and a perspective view of a gas generator with Ausfa1Isicherung,

15 shows a failure fuse in a second embodiment,

16 shows a fail-safe in a third embodiment,

17 shows an electric motor driven stop of the winding shafts with a perspective view of the drive,

18 shows a second embodiment of an electric motor operated stop of the winding shaft,

19 shows a damping device for tethers,

20a shows a fail-safe device in a fourth embodiment, Fig. 20b is a coordinate system in which the effect of two counter-rotating torsion springs shown in FIG. 16 is shown as well as

Fig. 20c is a coordinate system in which the relationship between the adjusting force and angular position of the two springs of FIG. 16 is shown.

In motor vehicles, gas bag restraint systems 1, which have a gas generator 2 and an airbag 3, have been used for some time. These serve to catch a vehicle occupant located on a vehicle seat 4 in the event of an accident and thus to avoid too high accelerations. If one wishes to adapt the functions of the gas bag restraint system, such as its shape or size achieved after deployment, to parameters relevant to occupant load, the invention proposes to provide a mechanical coupling in the form of a Bowden cable 5. If a vehicle seat occupies a forward position relative to the cockpit or to the steering wheel of the vehicle, then it can be assumed that there is a smaller and lighter person on the seat. For this person, a gas bag with a smaller extent in the X direction is required (see Fig. Ia). The invention is concerned with varying over the Bowden cable 5, the size of the airbag 3. If the vehicle seat 4 occupies a rear position in the vehicle, then it is to be assumed that a larger or heavier person is located on the vehicle seat and a gas bag with a larger extent in the X direction is required to adequately restrain the occupant (see FIG ).

This is achieved in that the Bowden cable 5 with one end to the vehicle seat 4 and with its other end to a Gas bag limiting device attacks. The airbag-limiting device has a storage device for at least one of the deployment path of the airbag limiting tether and will be described in more detail below.

FIG. 2 shows an exemplary embodiment of a storage device for a gas bag limiting device. The storage device consists of a winding shaft 6. The winding shaft 6 is hollow and, as explained below, rotatably mounted on a gas generator 7. The gas generator 7 is a commercially available gas generator with an ignition charge, not shown, and gas outlet openings 8 through which gas can escape from the gas generator 7 for deployment of the airbag. Around the winding shaft 6 around a housing 9 is arranged. The housing 9 is also substantially cylindrical and arranged around the gas generator 7 around. It is firmly connected to the gas generator 7 via fastening elements screws 11. The housing 9 has in the region of the gas outlet openings 8 of the gas generator recesses 12, which are designed so that they ensure a trouble-free escape of the gas flow.

The gas generator 7 is arranged with the winding shaft 6 and the housing 9 as a unit in a further housing 13, which serves to receive the gas generator 7 and the attachment of this gas generator 7 in the vehicle. For this purpose, the housing 13 flanges 14 with holes 15.

FIG. 3 shows the gas generator 7 in section in a housing 13. The gas outlet openings 8 in the gas generator 7 can be seen. Around the gas generator 7 around the winding shaft 6 is arranged. It is rotatable about bearing 16 relative to Gas generator 7 is arranged. Around the winding shaft 6 around the housing 9 can be seen, which is connected by screws 11 fixed to the gas generator 7.

The winding shaft 6 has several different areas. As can be seen from FIG. 2, the region of the winding shaft 6 situated above the gas outlet openings 8 of the gas generator 7 is provided with recesses 10 which serve to ensure unhindered escape of gas. In each case right and left of the area with the recesses 10 storage devices 17a to 17d are provided for Pangbänder. The storage devices 17 a to 17 d consist of grooves that extend radially around the winding shaft 6 around. They have a defined diameter D, which extends over a width adapted to the tethers. In the illustrated embodiment, the diameter D of the grooves 17a to 17d are the same size. The tethers, not shown, are wound around the winding shaft 6 in the corresponding grooves 17a to 17d. Each groove 17a to 17d takes on exactly one tether. Each groove is delimited laterally and has a Oberfläσhenbeschaffenheit, which always allows a reliable winding and unwinding of the tethers.

It is conceivable to make the diameters D of the grooves 17a to 17d different. In this way, a different length of each tether or a different lots can be provided via a winding shaft 6.

On one side of the winding shaft 6, another storage device 18 connects, which serves to receive the Bowden cable 5. The storage device 18 is a part of the winding shaft β or according to the Winding shaft 6 rotatably mounted on the gas generator 7 and with

1 of the winding shaft 6 firmly connected. It has a groove 19. The groove 19 serves to receive the Bowden cable 5. The Bowden cable 5 is fixed in the groove 19 with its one end.

In addition to the groove 19, a further groove 21 is provided in the storage device 18. This serves to receive a coil spring 22. The coil spring 22 is attached at its one end to the storage device 18 and the winding shaft 6 and with its other end to the fixed housing 9. Thus, the coil spring 22 causes the winding shaft 6, when no external forces act on them, always assumes a defined starting position.

The region 23 within the receptacle 13 above the gas generator 7 and the housing 9 serves to receive a folded gas bag, not shown.

Figure 4 shows in three-dimensional form the winding shaft 6 with the housing 9 in a sectional view. Evident are in the housing 9, the recesses 12 for the passage of the gas and receptacles 24 for the screws 11 for fixing the housing 9 to the gas generator 7. As described above, the winding shaft 6 is composed of different areas together. In the front area, the storage device 17c and 17d designed as grooves can be seen. This is followed by a perforated area with recesses 10 connects. Following this perforated area further storage device 17a and 17b are provided. This is followed by the storage device 18 for receiving the Bowden cable 5 and the coil spring 22. Evident is also the groove 19 for receiving the Bowden cable 5 and the groove 21 for receiving the coil spring 22. At the top of the winding shaft 6 in the region of the groove 19 is a slot 25th brought in. In the housing 9 and in the airbag housing or the receptacle 13 is also an unillustrated entrance opening is provided either in the form of a bore or in the form of a slot for the Bowden cable 5, so that this out of the airbag housing out can be. The storage device 18 is fixedly connected to the winding shaft 6. In this case, all compounds, such as adhesive or welded joints but also positive connections such as gears in question.

Figures 5a and 5b show another embodiment of the storage device 18 ', which is shown here detached from the winding shaft 6. This storage device 18 'differs from that described above in that the groove 21 for receiving the coil spring 22 has been supplemented by a second groove 19' for receiving a second Bowden cable. The second Bowden cable can be used as a replacement of the coil spring 22 and serve to reset the winding shaft 6 in its starting position. In other words, a Doppelbowdenzug is provided, each one Bowenzug is responsible for a direction of rotation. Furthermore, two slots 26 can be seen in the drawing, which open into holes 27. The slots 26 with the holes 27 serve to receive the ends of the Bowden cables and for permanent attachment of these ends to the winding shaft 6. In this way it is ensured that reliable power can be transmitted from the Bowden cables to the winding shaft 6. The storage device 18 'can, as already described above, be fastened to the winding shaft 6 via conventional fastening means.

The mode of operation of the gas bag restraint system according to the invention will now be described below. By an adjustment of the vehicle seat 4, a force is introduced into the Bowden cable 5. This force is transmitted through the Bowden cable 5 to the winding shaft 6, so that each position of the vehicle seat 4 is associated with a defined angular pitch of the winding shaft 6. The winding shaft 6 is fixed in this position by the Bowden cable 5 and this oppositely acting spring 22 so that it retains this position until the vehicle seat 4 is adjusted again, especially when the gas generator 7 is ignited and the gas bag 3 unfolds. On the winding shaft 6 are stored four tethers, which are wound around the winding shaft 6 and connected at one end firmly with this. By the influence of the Bowden cable 5 on the Wickewelle 6 and taking a certain angular position, a lot is set on the tethers. Thus, the stockpiled on the winding shaft 6 tethers on the respective position of the vehicle seat 4 adapted lots. Now, if the gas bag ignited, this lot is withdrawn from the winding shaft 6 until the lots is used up and pulls the tether on the fixed winding shaft 6, but can not continue to unwind. Thus, the angular position of the winding shaft 6 determines the lots and over the length of the available tether.

It may be provided in the set angular position additional means for locking or fixing the winding shaft 6. These can then be activated when the gas generator is ignited so that a reliable setting of the storage device is always possible before ignition. For example, it is conceivable to clamp the winding shaft 6 on the gas generator 7 during ignition of the gas generator. This can be achieved in that the winding shaft 6 is designed so that they deformed or arrested at the resulting pressure during ignition and thus rotation of the winding shaft 6 is prevented relative to the gas generator 7. By targeted material weakening on the gas generator 7 or winding shaft 6, for example, one or more Spreizklappen open, which in turn exert pressure from the inside against the winding shaft or housing and hold them over friction and / or positive engagement. Likewise, a locking mechanism may be provided, for example in the form of a pawl, which is activated upon ignition of the gas bag and the winding shaft 6 additionally holds. The airbag flap, which opens when unfolding the gas bag can also be used to lock the winding shaft 6.

The particular advantage of the invention is the fact that all parameters are already set before the ignition of the gas bag. This can be done automatically with each adjustment of the Pahrzeugsitzes 4. Once ignition and thus deployment of the airbag occurs, no variation is needed and no parts have to be moved during deployment. This leads to the system functioning reliably.

It is conceivable to provide an attenuator between the tether and the corrugation shaft 6, which serves to avoid force peaks in the tethers and to suppress excessive loading of the tethers.

The following explanations deal with the problem of only moving the winding shaft 6 when a critical driving situation has actually been detected. This has the advantage that the shaft does not have to move with every seat adjustment. FIG. 6 shows a winding shaft 6 'which is divided into three partial shafts 30,

31 and 32 is divided. The partial wave 30 and the partial wave

32 form the storage device for the tethers 33 and 34 and 35 and 36. The partial shaft 31 forms the storage device for two Bowden cables 37 and 38, which are connected to the Sitzverstelleinrichtung. As in the previous embodiments, both the partial shaft 30 and the partial shaft 32 grooves 39a to 39d, which serve to receive the tethers 33 to 36. In addition, recesses 10 are provided in the partial shafts 30 and 32, which serve to ensure an unhindered escape of gas. The partial shafts 30 to 32 are each provided with internal threads 40 which are brought into engagement with threaded sleeves 41. The threaded sleeves 41 are, as can be seen in particular from FIG. 7c, fastened on the gas generator 7.

Thus, the middle part of shaft 31 forms a stop for the movement of the partial shafts 30 and 32, as soon as they are rotated by the withdrawal of the tethers 33 to 36 in the direction of arrow A in rotation. The deduction of the tethers 33 to 36 thus causes a rotation of the partial shafts 30 and 32, which rotate the partial shafts 30 and 32 with its internal thread 40 on the threaded sleeves 41 and to move to acting as a stop part shaft 31. Depending on the seat adjustment, the partial shaft 31 can be adjusted either to the right or left on the threaded sleeve 41, so that either the right part shaft 30 or the left part shaft 32 first strikes the part shaft 31. This striking in turn causes the tethers of the respective partial wave are not further developed, so that a defined tether length is available for airbag molding. The mode of operation of the gas bag restraint system shown in FIGS. 6 and 7 is as follows: By adjusting the vehicle seat 4, a force is introduced into the Bowden cable 37 or 38. This force causes the partial shaft 31 to rotate on its threaded sleeve 41, so that the partial shaft 31 shifts to the right or left from its central position shown in FIG. 7c. This position of the partial shaft 31 is maintained until the vehicle seat 4 is adjusted again. Accordingly, the adjustment of the seat 4 has no direct influence on the winding of the tethers on the partial shafts 30 and 32. Only in an accident or anticipated by sensors safely detected accident in which the gas generator 7 is ignited, the tethers are 33 to 36 of their stocking device on the partial shafts 30 and 32 deducted. And so far, until the partial shaft 30 or 32 to the middle part of the shaft 31-abuts ab- described above. The stop is damped by a damping ring 29 which is arranged in each case a partial shaft 30 or 32 and is arranged between the partial shaft 30 or 31 or 32.

Figures 8 and 9 show an embodiment of the gas bag restraint system according to the invention, in which the winding shaft via a gear unit (44, 47-49) is particularly damped to prevent force peaks. For this purpose, the winding shaft 6 '' in turn divided into two partial shafts 42 and 43, which are connected to each other via a damping device 44. The two partial shafts 42 and 43 are analogous to those in the embodiment of Figures 6 and 7, but without internal thread. The partial shafts 42 and 43 run on bearing bushes 45, wherein the partial shaft 43 in the case of a critical driving situation with the Storage device 46 can be coupled. The storage device 46 is designed for storing Bowden cables.

The damping device 44 comprises a fixed on the gas generator 7 ring 47, project radially from the eight stub axles 48. On each of these stub axles 48, a damper wheel 49 is rotatably mounted.

With its teeth engages each damping wheel 49 in teeth 50 of the partial shaft 43 and 42, which are introduced into the respective corresponding end face. The independently rotatable partial shafts 42 and 43 thus influence each other. For example, if the tethers 33 and 34 completely withdrawn, so that the rotational movement of the partial shaft 42 is stopped, this abrupt stop attenuated via the damping device 44 is transmitted to the partial shaft 43, so that here no force peaks can arise.

Figures 10 and 11 show a modified embodiment of the solution described in Figures 6 and 7. The middle part shaft 31 'is designed together with its threaded sleeve 41' such that gas can escape from the outlet openings 8 unhindered. For this purpose, the partial shaft 31 'apertures 52, which are arranged similar to an impeller. The thread of the threaded sleeve 41 'is not completely circumferential but provided with recesses 53, in turn, openings 54 are introduced. The openings 54 are in overlap with the gas outlet openings 8 of the gas generator. 7

Figures 12 and 13 show perspective views of an inventive gas bag restraint system with partial waves 55 and 56, the different winding diameters D have. This means that the tethers 33 and 34 wound on partial shaft 55 can enable a considerably longer deployment distance of the gas bag than the tethers 35 and 36 wound on the partial shaft 56.

However, it is also possible to vary the winding diameter D on a single part shaft, as shown in FIG. Here, for example, the diameter of the tether 34 is kept smaller than the diameter of the tether 33rd

Figures 14, 15 and 16 show ways in which the winding shaft ensures a safe deployment of the gas bag in case of failure of the Bowden cable. For this purpose, it is provided that the winding shaft always occupies the 50% seat position automatically either in its rest position or in case of failure of the Bowden cable. For this purpose, as shown in FIGS. 15 and 16, counter-rotating springs 60 and 61 can be provided on the partial shaft 31 which receives the Bowden cables 37 and 38. The cradle springs 60 and 61 are fixed at one end to the split shaft 31 and at the other end to the fixed housing 9. Thus, the coil springs cause, if no external forces through the Bowden cables 37 and 38 act on the partial shaft 31, an automatic positioning of the partial shaft 31 on its threaded sleeve.

In order to prevent an adjustment of the part shaft 31 by the train of tethers during inflation of the airbag with the storage device for the Bowden cables 37 and 38, a lock may be provided according to Figure 14, which is activated when the gas generator. The lock 70 snaps with locking lugs 71 in the recesses provided in the 72 part shaft 31 and thus prevents them from rotating. The Partial shafts 30 and 32 can thereby move unhindered on the partial shaft 31 and strike it.

The motor-driven stop 80 shown in FIG. 17 for the winding shafts 30 and 32 includes an eccentric 81, which is rotated in response to the desired stop position by a servomotor 82. The eccentric 81 is connected via a gear 83 to the servo motor 82. A housing 84 receives a bearing 85 for the gear 83. Depending on the deflection of the eccentric either the left or the right winding shaft 30 or 32 can be further processed.

Alternatively, as the embodiment of FIG. 18 shows, a servomotor 86 driving a stop 87 which is slidably held by a rack gear 88.

In addition, the tethers can be secured by means of a damping device 89 against force peaks. For this purpose, the tethers are sewn so that when the burden of the retention of the gas bag fabric tears the seam and thus takes the force peaks of the attachment points of the tethers.

Similar to FIG. 16, the fail-safe mechanism according to FIG. 20a shows a possibility, such as, for example, that the winding shaft 32 can be held in a 50% position with compensation of the force / torque-free region around the middle position (see FIG. 20b). A pin 90, which is held by a spring 91 in the direction of the winding shaft under bias, causes the winding shaft 32 is always held in the 50% position, since it engages in a recess 92 of the winding shaft 32. Only by the Bowden cables, not shown here, the winding shaft 32 is rotated from its position. With the two opposite winding springs is brought in possibly defective Bowden cables the winding shaft in the safe working position (50% position). By this measure Federktafttoleranzen (typically up to 20%) can be compensated or compensated.

Of course, the preceding embodiments can be combined with each other to achieve an optimal retention effect or adjustment of the gas bag.

Claims

DaimlerChrysler AGPatent claims

1. airbag restraint system (1) with an airbag (3), a gas generator (2) and an airbag limiting device that limits the maximum deployment path of the airbag (3) depending on occupant load relevant parameters, wherein the airbag-limiting device is a storage device for at least a limiting band that delimits the deployment path of the gas bag (3), characterized in that the storage device is arranged outside the gas bag (3).

2. Airbag restraint system according to claim 1, characterized in that the maximum unfolding distance in dependence on the position of the restraint system (1) associated vehicle seat (4).

3. Airbag restraint system according to claim 1 or 2, characterized in that a mechanical coupling between the position of the Vehicle seat (4) and the airbag limiting device (1) is provided.

4. Airbag restraint system according to one or more of the preceding claims, characterized in that a Bowden cable (5) is provided as a mechanical coupling.

5. Airbag restraint system according to one or more of the preceding claims, characterized in that as a storage device for the tether a

Winding shaft (6) is provided.

β. The gas bag restraint system according to one or more of the preceding claims, characterized in that the winding shaft (6) is arranged in a receptacle (13) of the gas generator (7).

7. Airbag restraint system according to one or more of the preceding claims, characterized in that the winding shaft (6) is rotatably mounted on the gas generator (7) and disposed within the receptacle (13) of the gas generator (7).

8. Airbag restraint system according to one or more of the preceding claims, characterized in that the winding shaft (6) with the Bowden cable (5) is connected.

9. Airbag restraint system according to one or more of the preceding claims, characterized in that the winding shaft (6) serves as a Bevratsratung device for several Pangbänder.

10. Airbag restraint system according to one or more of the preceding claims, characterized in that the winding shaft (6) has different diameters for the storage of several Pangbändern.

11. winding shaft for a gas bag restraint system according to one or more of the preceding claims, characterized in that the winding shaft (6, 6 ', 6' ') at least two

Partial shafts (30, 31, 32, 42, 43, 46, 55, 56,) comprises.

12. Winding shaft according to claim 11, characterized in that at least one partial shaft with internal thread (40) is provided, which is in engagement with a on the gas generator (7) threaded sleeve (41).

13. Winding shaft according to claim 11, characterized in that one of the partial shafts (31) is designed as a stop for the rotational movement of another partial shaft (30, 32).

14. Winding shaft according to claim 11, characterized in that between the winding shafts, a transmission unit (44, 47-49).

15. Winding shaft according to claim 12, characterized in that the threaded sleeve (41) has openings (54) for the gas outlet.

16 winding shaft according to one of claims 11 to 15, characterized in that a fail-safe is provided, which causes an automatic alignment of the winding shaft.

17. Winding shaft according to claim 16, characterized in that the fail-safe is a lock (70)

18. Winding shaft according to claim 16, characterized in that in addition a locking or locking by the gas generator or airbag flap is provided.

19. Winding shaft according to claim 16, characterized in that the failsafe by two opposing coil springs (60, 61) is formed.

20. Winding shaft according to claim 16, characterized in that the failure insurance has two opposing springs.

21, gas bag restraint system according to claim 1, characterized in that the maximum unfolding distance in dependence on the position of the restraint system (1) associated occupant takes place.

22. Airbag restraint system according to claim 1 or 21, characterized in that a coupling between the position of the occupant and the airbag-limiting device (1) is provided with electrical adjusting device.