U.S. patent application number 10/035938 was filed with the patent office on 2002-07-04 for gas bag module.
This patent application is currently assigned to TRW Automotive Safety Systems GmbH & Co. KG. Invention is credited to Bohn, Stefan.
Application Number | 20020084640 10/035938 |
Document ID | / |
Family ID | 7950648 |
Filed Date | 2002-07-04 |
United States Patent
Application |
20020084640 |
Kind Code |
A1 |
Bohn, Stefan |
July 4, 2002 |
GAS BAG MODULE
Abstract
The invention relates to a gas bag module comprising a gas bag,
an outer contour of the gas bag being defined by a gas bag wall
which has a front wall for the impact of an occupant with a centric
opening as a transition to an indentation in the gas bag. The
indentation is formed in that during inflation a center portion of
the gas bag wall is prevented from freely moving and is restrained.
A closure part is provided which encloses one of the indentation
and the opening and engages the gas bag wall. A traction means is
provided which is connected with the closure part. The traction
means is attached such that due to a deployment of the gas bag a
tensile force is exerted on the traction means and the tensile
force is passed on to the closure part, and one of the indentation
and the opening being at least partly closed.
Inventors: |
Bohn, Stefan; (Goldbach,
DE) |
Correspondence
Address: |
TAROLLI, SUNDHEIM, COVELL, TUMMINO & SZABO L.L.P.
111 LEADER BLDG.
526 SUPERIOR AVENUE
CLEVELAND
OH
44114-1400
US
|
Assignee: |
TRW Automotive Safety Systems GmbH
& Co. KG
|
Family ID: |
7950648 |
Appl. No.: |
10/035938 |
Filed: |
December 26, 2001 |
Current U.S.
Class: |
280/743.1 ;
280/743.2 |
Current CPC
Class: |
B60R 2021/23382
20130101; B60R 21/2338 20130101; B60R 21/233 20130101 |
Class at
Publication: |
280/743.1 ;
280/743.2 |
International
Class: |
B60R 021/16 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 2000 |
DE |
200 22 016.0 |
Claims
1. A gas bag module comprising a gas bag, an outer contour of said
gas bag being defined by a gas bag wall which has a front wall for
the impact of an occupant with a centric opening as a transition to
an indentation in said gas bag, said indentation being formed in
that during inflation a center portion of said gas bag wall is
prevented from freely moving and is restrained, a closure part
which encloses one of said indentation and said opening and engages
said gas bag wall, and a traction means being provided which is
connected with said closure part, said traction means being
attached such that due to a deployment of said gas bag a tensile
force is exerted on said traction means and said tensile force is
passed on to said closure part, and one of said indentation and
said opening being at least partly closed.
2. The gas bag module as claimed in claim 1, wherein said traction
means is on the one hand connected to said gas bag wall and on the
other hand to said closure part.
3. The gas bag module as claimed in claim 1, wherein in a
completely inflated condition of said gas bag said traction means
runs obliquely outwards to a lateral portion of said gas bag wall,
said traction means being attached to said lateral portion.
4. The gas bag module as claimed in claim 1, wherein said traction
means is disposed in an interior of said gas bag.
5. The gas bag module as claimed in claim 1, wherein said closure
part is one of a strap and a rope surrounding one of said
indentation and said opening.
6. The gas bag module as claimed in claim 1, wherein said closure
part is accommodated in a guideway provided in said gas bag wall so
as to be movable with respect to said gas bag wall.
7. The gas bag module as claimed in claim 1, wherein said closure
part and said traction means are integrally connected with each
other.
Description
TECHNICAL FIELD
[0001] This invention relates to a gas bag module comprising a gas
bag.
BACKGROUND OF THE INVENTION
[0002] There are gas bags in which an outer contour of the gas bag
is defined by a gas bag wall which has a front wall for the impact
of the occupant with a centric opening as a transition to an
indentation in the gas bag, the indentation being formed in that
during inflation a center portion of the gas bag wall is prevented
from freely moving and is restrained. In such ring-shaped gas bags,
the center portion which in a conventional gas bag is presented to
the occupant, is prevented from moving towards the occupant in that
it remains fixedly attached to the module. In this arrangement,
restraint is effected via the ring-shaped front wall around the
indentation. The indentation which is not filled with gas is to be
as small as possible so as to help the head of the occupant to be
intercepted as safe as possible.
BRIEF SUMMARY OF THE INVENTION
[0003] The invention provides a gas bag module in which the
indentation is closed at least in part, preferably even completely
closed. This is achieved in a gas bag module which comprises a gas
bag, an outer contour of the gas bag being defined by a gas bag
wall which has a front wall for the impact of an occupant with a
centric opening as a transition to an indentation in the gas bag.
The indentation is formed in that during inflation a center portion
of the gas bag wall is prevented from a free movement, preferably
from any movement, and is restrained. A closure part is provided
which encloses one of the indentation and the opening and engages
the gas bag wall. A traction means is connected with the closure
part. The traction means is attached such that due to a deployment
of the gas bag a tensile force is exerted on the traction means and
the tensile force is passed on to the closure part, and one of the
indentation and the opening being at least partly closed.
[0004] In the gas bag module according to the invention a closure
part is provided preferably in the region of the transition from
the front wall to the indentation (i.e. the opening), or in the
region of the indentation and as close as possible to the front
wall, which closure part is actuated by the traction means and at
least largely closes the opening or the indentation. The closing
force is generated by the gas bag itself during the process of
deployment. The opening in the front wall or the indentation thus
has a much smaller open cross-sectional area than in the case of a
gas bag formed without closure part and without traction means, but
otherwise is formed identically.
[0005] Preferably, the traction means is on the one hand connected
to the gas bag wall and on the other hand to the closure part. The
gas bag wall is displaced during deployment, so that the traction
means is moved relative to the gas bag wall, whereby the tensile
force required for actuating the closure part is produced.
[0006] In the completely inflated condition of the gas bag, the
traction means preferably runs obliquely outwards, i.e. sidewards,
to a lateral portion of the gas bag wall to which it is attached.
This formation ensures that the traction means does not produce any
recess or indentation in the region of the opening, when the
traction means would act as a limiting strap.
[0007] The traction means may be arranged outside the gas bag, so
as to extend along the gas bag wall, or in accordance with the
preferred embodiment in the interior of the gas bag, i.e. within
the chamber to be inflated, whereby a relatively plain outside wall
is available for the occupant for restraint purposes.
[0008] The closure part preferably is a strap or rope surrounding
the indentation or the opening.
[0009] Furthermore, a guideway is preferably provided in the gas
bag wall, in which guideway the closure part is accommodated so as
to be movable with respect to the gas bag wall, similar to a bag
the opening edge of which has been folded over and sewn, so that
the bag can be pulled tight by means of a rope accommodated
therein.
[0010] Preferably, closure part and traction means are made in one
piece, preferably as a strap or a rope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a cross-sectional view of an embodiment of the
gas bag module according to the invention, with the gas bag not yet
completely inflated, and
[0012] FIG. 2 shows a cross-section through the gas bag module as
shown in FIG. 1 with the gas bag almost completely inflated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] FIG. 1 shows a gas bag module which has a gas bag 3, a gas
generator 5 and a module housing 7 with a module cover 9 in the
form of flaps. The gas generator 5 is surrounded by a pot-shaped or
bell-shaped diffuser 10, which has been put over the gas generator
from above and is attached to the module, more precisely to the
module housing 7. Instead of the diffuser 10 any other component
surrounding the gas generator 5 and firmly attached to the module
may be provided.
[0014] The gas bag, which is a front gas bag arranged in the
steering wheel or in the dashboard, has a gas bag wall which
consists of several portions. One of these portions is the front
wall 11, which faces the occupant in the inflated condition (FIG.
2), and which the same can impact upon in the case of restraint.
Moreover, a surrounding lateral portion 12 and a rear wall 13 are
provided. The front wall has a centric opening 15, from which the
gas bag wall extends towards inside, to the diffuser 10, so that a
deep indentation is formed which usually is open from the outside
and is provided with the reference numeral 17. The gas bag wall
defining the indentation is designated with the reference numeral
14. The opening 15 defines a transition from the front wall 11 to
the indentation 17.
[0015] Usually, the gas bag consists of various fabric parts,
namely two outer, ring-shaped fabric parts 18 and 20 sewn by means
of the surrounding seam 16 as well as two inner fabric parts 22,
24, which are connected with each other at the surrounding seam 26,
the fabric part 22 being sewn to the fabric part 20 at the edge of
the opening 15.
[0016] The indentation 17 is formed in that the lowermost part
(center portion 54) of the fabric part 24 is permanently attached
to the diffuser 10 and in the case of restraint, during inflation,
is prevented from moving towards outside.
[0017] By means of the indentation 17 a ring-shaped chamber 30 to
be filled with gas is obtained. The indentation 17 is not to be
filled with the gas of the gas generator.
[0018] In the interior of the chamber 30 a rope or pull strap 16 is
disposed, which with its free ends is disposed between the fabric
layers 18, 20 and is attached to the gas bag wall by the seam 16.
The pull strap is thus attached to the lateral portion 12 of the
gas bag wall. In the completely inflated condition, it obliquely
extends upwards towards the opening 15, where it extends around the
edge of the opening 15 and is accommodated in a guideway in the gas
bag wall in the region of the edge of the opening 15 so as to be
movable with respect to the gas bag wall, similar to a closure rope
sewn in at the edge of a bag. The guideway is formed in that on the
radially inner side a first connecting seam 40 is provided, by
means of which the fabric layers 20, 22 are sewn. Radially spaced
from this seam 40 a second seam 42 extends around the opening, and
this seam is not closed completely in the circumferential
direction, so that the pull strap 32 can get out of the
guideway.
[0019] The portion of the pull strap 32, which extends outside the
guideway, is referred to as traction means 100, and the portion
inside the guideway circumscribing the opening 15 is referred to as
closure part 102.
[0020] In the case of restraint, the gas bag module operates as
follows: Via the gas generator 5, gas is introduced into the
chamber 30, so that the gas bag being deployed urges the cover 9
towards outside. There is obtained a ring-shaped outlet opening 52
through which the gas bag can leave the module. There is not shown
a circular middle part of the cover, which rests against the center
portion 54 above the same and is permanently attached to the
diffuser 10, so that it does not swivel towards outside when the
cover 9 is opened.
[0021] The gas bag is deployed further towards the occupant, the
ring-shaped front wall 11 moving towards the occupant more and
more, but still having a large opening 15. Due to the fact that the
pull strap 32 bridges a longer portion of the gas bag wall, a
tensile force is exerted on the pull strap 32, for instance because
the lateral portion 12 of the gas bag wall tends to further bulge
towards outside in the direction X. Due to the tensile force, the
pull strap 32 is displaced in the direction of the arrow R and
completely or almost completely pulls tight the opening 15, as this
is represented in FIG. 2.
[0022] The occupant thus faces an almost or even completely closed
front wall 11.
[0023] The pull strap 32 might also be disposed outside the chamber
30 and be displaced by the gas bag wall bulging towards outside, so
as to achieve the closure of the opening 15. Moreover, there might
also be provided two or more catch straps oppositely disposed at
the indentation 17, to provide the gas bag with a symmetrical
shape.
[0024] The closure part 102 need not loop around the opening
directly at the transition from the front wall 11 to the
indentation 17, for it might also surround the fabric part 22 for
instance in the uppermost third of the indentation (see closure
part 102' shown in broken lines in FIG. 2) and in that way close
the indentation in the region of the opening 15.
* * * * *