Title: Head protective airbag and device
Abstract: A head protective airbag which is adapted to not be inflated or to be scarcely inflated when dragged out of a pillar cover is provided. The airbag can be extremely smoothly pulled or dragged out of the pillar cover. The head protective airbag is provided with a triangular first cell in a front portion of the airbag. The first cell is in communication with a gas inlet through first and second gas passages. As an inflator is actuated, gas flows first mainly into the first gas passage through the gas inlet so that the airbag pushes and opens a roof trim above a B-pillar and thus starts to deploy into a vehicle cabin. The first cell is pulled by the first gas passage and an area around the first gas passage so as to tear a trim of an A-pillar and come out of the trim. After that, the first cell is inflated.
Patent Number: 6,971,665 Issued on 12/06/2005 to Tanaka
| Inventors:
|
Tanaka; Tadashi (Asaka, JP)
|
| Assignee:
|
Takata Corporation (Tokyo, JP)
|
| Appl. No.:
|
387868 |
| Filed:
|
March 14, 2003 |
Foreign Application Priority Data
| Mar 19, 2002[JP] | 2002-076617 |
| Current U.S. Class: |
280/729; 280/730.2 |
| Intern'l Class: |
B60R 021/22; B60R 021/24 |
| Field of Search: |
280/729,730.2,743.1,743.2,730.1,749
|
References Cited [Referenced By]
U.S. Patent Documents
| 6409211 | Jun., 2002 | Sheng et al.
| |
| 6450527 | Sep., 2002 | Kobayashi et al.
| |
| 6527296 | Mar., 2003 | Bakhsh et al.
| |
| 6659502 | Dec., 2003 | Breyvogel et al.
| |
| 2002/0014762 | Feb., 2002 | Bakhsh et al.
| |
| 2002/0020991 | Feb., 2002 | Tanase et al.
| |
| 2004/0026907 | Feb., 2004 | Takahara.
| |
| Foreign Patent Documents |
| 101 19 198 | Nov., 2001 | DE.
| |
| 1 182 099 | Feb., 2002 | EP.
| |
| 10-291457 | Nov., 1998 | JP.
| |
| 2000/-296751 | Oct., 2000 | JP.
| |
| 2001/-106014 | Apr., 2001 | JP.
| |
| 2001/-163158 | Jun., 2001 | JP.
| |
| 2001/-163161 | Jun., 2001 | JP.
| |
| 2001/-180423 | Jul., 2001 | JP.
| |
| 2001/-233155 | Aug., 2001 | JP.
| |
| 2001/-260796 | Sep., 2001 | JP.
| |
Primary Examiner: English; Peter C.
Attorney, Agent or Firm: Foley & Lardner LLP
Claims
1. A head protective airbag to be disposed to extend along a pillar and a roof
side rail of a vehicle, comprising:
a first cell having a first side extending along the pillar;
a second cell extending away from the roof side rail; and
a gas passage positioned to carry gas from a top to a bottom of the airbag for
introducing gas only into the first cell;
wherein the passage is connected to the first cell only at a second side opposite
to the first side of the first cell.
2. The head protective airbag of claim 1,
wherein the gas passage includes a first portion extending substantially vertically
from an upper portion to a lower portion of the head protective airbag, and a second
portion extending along a lower side of the head protective airbag and connecting
the first portion of the gas passage to the first cell.
3. A head protective airbag as claimed in claim 2, wherein the second cell is
positioned to extend along the first portion of the gas passage.
4. The head protective airbag of claim 1, wherein the first cell is configured
so that when inflated the first cell has a substantially triangular profile; and
wherein the gas passage is connected adjacent to a corner of the triangular profile
opposite to the first side of the first cell.
5. The head protective airbag of claim 1, further comprising a gas supply means
for supplying gas into the head protective airbag.
6. An airbag for the side of a vehicle comprising:
a plurality of inflatable cells positioned along a longitudinal direction of
the vehicle, wherein each of the inflatable cells is configured so that gas is
introduced into the cell adjacent only a top or a bottom of the airbag;
a gas inlet having a first end adapted to be connected to an inflator and a second
end fluidly connected to the plurality of inflatable cells, wherein the gas inlet
is configured so that gas from the inflator enters the airbag only through the
second end of the gas inlet; and
a first gas passage extending in a vertical direction and located between at
least two of the inflatable cells;
wherein one end of the gas passage is positioned opposite the second end of the
gas inlet so that the gas passage inflates downwardly prior to any substantial
inflation of any of the plurality of cells.
7. The airbag of claim 6, wherein a second gas passage is fluidly connected to
the bottom of the gas passage and extends generally horizontally to supply inflation
gas to a first one of the plurality of inflatable cells.
8. The airbag of claim 7, wherein the first one of the plurality of cells is
triangular in shape.
9. The airbag of claim 7, wherein the first one of the plurality of cells is
positioned to extend along a pillar of the vehicle.
10. The airbag of claim 7, wherein a third gas passage is fluidly connected to
the bottom of the first gas passage and extends generally horizontally towards
the rear of the vehicle to supply inflation gas to a second one of the plurality
of inflatable cells.
11. The airbag of claim 7, wherein a second inflatable cell is positioned rearward
from said first inflatable cell and above the second gas passage, wherein gas for
inflating the second inflatable cell does not pass through the first gas passage.
12. The airbag of claim 11, wherein the second inflatable cell is located forward
of the first gas passage.
13. The airbag of claim 11, further comprising a third inflatable cell positioned
rearward from the first gas passage, wherein gas for inflating the third inflatable
cell does not pass through the first gas passage.
14. The airbag of claim 6,
wherein the gas passage is located in a midsection of the airbag relative to
the longitudinal direction of the vehicle; and
wherein the airbag is configured so that the gas passage inflates prior to the
inflatable cells so that as the gas passage inflates, the inflatable cells are
pulled out of a storage position prior to inflating.
15. The airbag of claim 14, wherein the gas passage is positioned so that inflation
gas for at least one of the inflatable cells must pass through the gas passage.
16. The airbag of claim 15, wherein the gas passage supplies inflation gas to
a triangular shaped first inflatable cell located at a forward most part of the airbag.
17. The airbag of claim 14, wherein one end of the gas passage is positioned
adjacent a position wherein the airbag is configured to receive inflation gas from
an inflator.
Description
BACKGROUND
The present invention relates to a protective airbag for protection of a vehicle
occupant's head and, more particularly, to an airbag which is to be inflated to
expand over windows of side doors in the event of a lateral collision or roll-over
of a vehicle.
Airbag for protection of a vehicle occupant's head is disposed along a corner
formed by a roof and a side portion of a vehicle cabin in the normal state and
is adapted to be inflated with gas introduced through gas inlets to expand over
windows of side doors.
Most of such head protective airbags are of a type which is disposed from an
A-pillar along a roof side rail. Among the head protective airbags, there is a
type not to allow the inflation of a portion along the A-pillar and a type to allow
the inflation of a portion along the A-pillar. The present invention relates to
a head protective airbag of a type to allow a portion along the A-pillar to be
inflated just like the latter type and to a head protective airbag device with
the head protective airbag.
FIGS. 6A-6C and FIG. 7 show the structure of a conventional head protective
airbag (Japanese Unexamined Patent Publication No. H10-291457, incorporated by
reference herein) which is adapted to allow a portion along the A-pillar to be
inflated. FIG. 6(A) is a perspective view showing the airbag in a state of being
inflated by introduction of gas, and FIGS. 6B and 6C are sectional views taken
along a line B—B and a line C—C of FIG. 6(A), respectively. FIG. 7
is an illustration showing the airbag in a state of being inflated within a vehicle cabin.
The airbag
41 comprises two sheets
42,
43 which are superposed
on each other and joined together along their peripheral edges to form chambers
(cells)
51-
59 extending vertically.
The upper portions of the chambers
51-
59 are in fluid communication
with an upper chamber
60 extending along the upper edge of the airbag
41.
Formed in the sheet
42 is an opening
60a for allowing gas
to be supplied into the upper chamber
60. Portions between adjacent chambers
51-
59 are defined as webs
61-
68 into which no gas is
permitted to be introduced.
The airbag
41 is folded by pulling the lower edge thereof up and is disposed
along about a roof side rail i.e. a corner formed by a roof
71 and a side
portion of a vehicle
70, an A-pillar
78, and a C-pillar
79.
The airbag
41 is covered by a suitable cover such as a pillar trim and a
roof trim (not shown).
The airbag
41 having the aforementioned structure acts as follows. When
the vehicle
70 is involved in a lateral collision or roll-over, gas is supplied
into the upper chamber
60 through the opening
60a. The gas
inflates the upper chamber
60 and the vertical chambers
51-
59,
whereby the airbag
41 pushes and opens the aforementioned cover and expands
over the windows of side doors. The airbag
41 lies between the occupant's
head and the side portion of the vehicle, thereby protecting the occupant's head.
When the window is opened, the occupant's body is protected from being thrown out
of the vehicle by the airbag.
In a conventional head protective airbag which is adapted to allow the inflation
of a portion along a pillar, the airbag starts to be inflated within the cover
and pushes and opens the cover, whereby the airbag deploys into the vehicle cabin.
Therefore, the cover must have a large enough opening to allow the deployment of
the already expanding airbag.
SUMMARY
It is an object of the present invention to provide a head protective airbag
which
is adapted to allow the inflation of a portion along a pillar, but not to allow
or scarcely allow the inflation before it is pulled or dragged out of a pillar
cover, whereby the portion can be extremely smoothly dragged out of the pillar
cover and to provide a head protective airbag device provided with the airbag.
A head protective airbag of the present invention is a head protective airbag
to
be disposed to extend along at least one pillar and a roof side rail, comprising
one or more first cell extending along the pillar, and one or more second cell
extending along the roof side rail, wherein a passage for introducing gas into
the first cell is connected to the first cell only at a portion opposite to the
pillar side of the first cell.
In addition, a head protective airbag device of the present invention comprises
the above head protective airbag and a gas supply means for supplying gas into
the head protective airbag.
In the head protective airbag and airbag device, during gas is introduced into
the airbag to inflate the airbag, the introduction of gas into the first cell extending
along the pillar is conducted only through the gas passage connected to the portion
opposite to the pillar side of the first cell. In this case, the gas passage is
inflated with gas prior to the inflation of the first cell. Until the gas passage
is inflated, the airbag pushes and opens a cover so as to start to deploy into
a vehicle cabin. Therefore, the first cell is pulled by a portion including the
inflated gas passage, whereby the first cell opens the pillar cover and is pulled
out into the vehicle cabin before the first cell starts to be inflated or the cells
are inflated a little. Since the first cell which is not or scarcely inflated is
still small in volume, the first cell can be smoothly pulled out with little interference
with the pillar cover. Then, the first cell coming out of the cover can be smoothly
inflated with introduced gas without any restraint by the pillar cover.
The gas passage preferably includes a first gas passage extending substantially
vertically from an upper portion to a lower portion of the head protective airbag,
and a second gas passage extending along the lower side of the head protective
airbag and connecting the first gas passage to the first cell.
According to an embodiment of the invention, after the first gas passage
extending vertically is inflated to deploy downwardly, the second gas passage is
inflated whereby the first cell is dragged out of the pillar cover.
In this case, it is preferable that the at least one second cell is disposed
along
the first gas passage. According to this head protective airbag, when the first
gas passage of the airbag is inflated to deploy downwardly, the second cell is
pulled downwardly by the inflated first gas passage. Therefore, the second cell
can be smoothly inflated.
According to the present invention, it is preferable that the first cell
is formed substantially in a triangular profile of which one side extends along
the pillar and the gas passage is connected to a portion including an opposing
corner of the one side of the triangular profile. Since the triangular first cell
starts to come out of the pillar cover at an apex (the aforementioned corner) of
the triangular profile, the resistance applied to the first cell by the pillar
cover is extremely small.
It is to be understood that both the foregoing general description and the following
detailed description are exemplary and explanatory only, and are not restrictive
of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention
will become apparent from the following description, appended claims, and the accompanying
exemplary embodiments shown in the drawings, which are briefly described below.
FIG. 1 is a front view, as seen from a vehicle cabin, showing a head protective
airbag according an embodiment of the present invention.
FIG. 2 is an illustration showing a deployment process of the head protective airbag.
FIG. 3 is an illustration showing a deployment process of the head protective airbag.
FIG. 4 is an illustration showing a deployment process of the head protective airbag.
FIG. 5 is a front view, as seen from a vehicle cabin, showing a head protective
airbag according another embodiment.
FIGS. 6A-6C are illustrations for explaining a conventional head protective airbag.
FIG. 7 is an illustration for explaining the conventional head protective airbag.
DETAILED DESCRIPTION
Hereinafter, embodiments of the present invention will be described
with reference to the attached drawings. FIG. 1 is a front view, as seen from a
vehicle cabin, showing a head protective airbag according an embodiment of the
present invention and FIGS. 2-4 are illustrations showing deployment processes
of the head protective airbag. In the following description, the longitudinal direction
is the longitudinal (back-and-forth) direction of a vehicle to which the head protective
airbag is installed.
A head protective airbag (hereinafter, sometimes simply called "airbag")
1
of this embodiment is folded and disposed to extend from an A-pillar
31
to a C-pillar
33 through a roof side rail
32 of a vehicle
30.
The airbag
1 has substantially a trapezoidal profile in the deployment state
so that it is inflated into a curtain shape to extend along a side surface of the
vehicle cabin from the roof side rail
32 and the respective pillars
31,
33 to the vicinity of the upper edges of front and rear door panels
34,
35 so as to cover over the upper half of a side face of the vehicle cabin
in the event of a lateral collision or roll-over of a vehicle.
That is, the airbag
1 has a front side la to be extending along the A-pillar
31, a lower side l
b to be extending along the upper edges of the
door panels
34,
35, a rear side
1c to be extending
along the C-pillar
33, and an upper side
1d to be extending
along the roof side rail
32 wherein the lower side l
b is longer than
the upper edge
1d so that the airbag
1 substantially has a
trapezoidal profile.
The airbag
1 comprises two sheets which are joined to each other by joints
including a line-shaped joint
2 extending around their peripheries (with
some parts thereof extending inward of the sheets), line-shaped joints
3-
7
extending inside the peripheries, and circular joints
8-
14 for reinforcing
areas around ends of the line-shaped joints
3-
7. The airbag
1
is designed to be inflated by introduction of gas into spaces between the sheets.
It should be noted that the line-shaped joints
2-
7 and the circular
joints
8-
14 may be formed by any of various joining means such as
sewing, bonding, and welding.
The airbag
1 has an L-shaped projection
15 extending from a middle
portion in the longitudinal direction of the upper side
1d thereof.
Formed in the projection
15 is a gas inlet
16 for introducing gas
into the airbag
1. A gas generator (inflator)
17 is connected to
the gas inlet
16 for inflating the airbag
1. In an alternative embodiment,
the projection
15 may be a separate piece from the airbag
1.
The line-shaped joint
2 comprises a front part
2a extending
along the front side
1a, a lower part
2b extending
along the lower side
1b, a rear part
2c extending along
the rear side
1c, and an upper part
2d extending along the
upper side
1d of the airbag
1.
The line-shaped joint
3 extends to communicate with a circular joint
8
which is disposed near a corner formed by the front side
1a and the
upper side
1d of the airbag
1. The circular joint
8
is positioned to border on or quite close to the line-shaped joint
2 at
the corner.
The line-shaped joint
3 is formed in a U-like shape comprising a front
part
3a extending diagonally from the circular joint
8 to
the lower back of the airbag
1, a middle part
3b as a continuation
of the front part
3a and extending substantially in the longitudinal
direction at about the middle in the vertical direction of the airbag
1,
and a rear part
3c extending from the middle part
3b toward
a middle portion in the longitudinal direction of the upper side
1d of
the airbag and connected to a circular joint
9.
The middle part
3b of the line-shaped joint
3 is spaced
apart from the line-shaped joint
2 extending along the lower side
1b
of the airbag, thereby forming a second gas passage
22 between the line-shaped
joint
2 and the middle part
3b of the line-shaped joint
3.
The second gas passage
22 extends in the longitudinal direction along the
lower part
2b of the line-shaped joint
2 in a lower portion
of the airbag
1.
A first cell
18 formed substantially in a triangular profile is defined
by the front part
3a of the line-shaped joint
3 extending
diagonally to the lower back, a front-side portion of the lower part
2b
of the line-shaped joint
2 extending in the longitudinal direction,
and the front part
2a of the line-shaped joint
2 extending
along the A-pillar
31. The triangular first cell
18 communicates
with the second gas passage
22 at an opposing corner of the front part
2a
of the line-shaped joint of the first cell
18, that is, at a corner
between the rear side and the lower side of the first cell
18.
Inside the first cell
18, a line-shaped joint
4 formed substantially
in a triangular profile which is similar to and smaller than the figure of the
first cell
18 is formed. An inside area
19 defined by the line-shaped
joint
4 is a non-inflatable portion into which no gas is introduced. The
non-inflatable portion acts to prevent the thickness of the airbag when inflated
from being too large. The line-shaped joint
4 extends in a loop starting
from a circular joint
10 and returning to the circular joint
10.
Formed between the rear part
3c of the line-shaped joint
3
and a line-shaped joint
6 is a first gas passage
21. The upper portion
of the first gas passage
21 faces the aforementioned gas inlet
16
and the lower portion of the first gas passage
21 communicates with the
second gas passage
22. The first gas passage
21 extends in the vertical
direction at a middle portion in the longitudinal direction of the airbag
1.
A second cell
20a is defined along the front-side of the first
gas
passage
21. The second cell
20a is formed in a U-like shape
between the line-shaped joint
3 and the line-shaped joint
5. In this
embodiment, two circular joints
11 and
12 are formed at substantially
the same level (height) with of the circular joint
9 in front of the circular
joint
9. The line-shaped joint
5 is formed to extend in a U-like
shape between the circular joints
11 and
12.
A line-shaped joint
6 is in formed substantially in a C-like shape as a
continuation of the lower part
2b of the line-shaped joint
2,
extending upwardly at a middle portion in the longitudinal direction of the airbag
1, and being curved rearwardly toward a circular joint
13.
The lower part
2b of the line-shaped joint
2 extends substantially
into a Ω-like shape between a middle portion and a rear portion of the airbag
1 and returns to the vicinity of the lower side
1b of the
airbag
1. An area
24 defined and surrounded by the lower part
2b
of the line-shaped joint
2 in the Ω-like shape is a non-inflatable
portion into which no gas is introduced. A cell
23a is formed between
this area
24 and the first gas passage
21, a cell
23b is
formed between this area
24 and a line-shaped joint
7, and a cell
23c is formed between the line-shaped joint
7 and the rear
part
2c of the line-shaped joint
2.
The line-shaped joint
7 branches from a portion near the lower end of
the rear part
2c of the line-shaped joint
2 and extends upwardly
to reach a circular joint
14.
The circular joints
11,
12,
9,
13,
14 are
positioned substantially at the same level (height), thereby forming a narrow gas
passage, extending along the upper side
1d of the airbag
1,
between these circular joints
11,
12,
9,
13,
14
and the upper part
2d of the line-shaped joint
2.
The airbag
1 is folded by pulling the lower edge thereof up and is disposed
along about the roof side rail
32, the A-pillar
31, and the C-pillar
33. In a storage position, the airbag
1 is covered by a suitable
cover such as a pillar trim and a roof trim (not shown).
The airbag
1 having the aforementioned structure acts as follows. When
the vehicle is involved in a lateral collision or roll-over, the inflator
17
is activated to supply gas into the airbag
1. The gas from the inflator
17 flows through the gas inlet
16 mainly to the first gas passage
21 so as to inflate the middle portion in the longitudinal direction of
the airbag
1 downwardly as shown in FIG. 3. Then, the airbag
1 pushes
and open a roof trim
36B above a B-pillar
37 and thus starts to deploy
into the vehicle cabin.
After the middle portion of the airbag
1 further deploys along the B-pillar
from the state shown in FIG. 3, gas flows into the second gas passage
22
so that the lower edge portion of the airbag
1 is also inflated. At the
time when the second gas passage
22 starts to be inflated, a portion about
the first cell
18 of the airbag
1 is pulled or dragged by already-inflated
portions of the airbag
1, i.e. the second gas passage
22 and the
area around the second gas passage
22, so as to tear a trim
36A of
the A-pillar and come out of the trim
36A. Gas from the second gas passage
22 is introduced into the first cell
18 thus pulled out, thereby
inflating the first cell
18.
As described above, according to one embodiment of the present invention, the
inflation of the first cell
18 is carried out after the first cell
18
is dragged out of the trim
36A. When the first cell
18 comes out
of the A-pillar trim
36A, the first cell
18 is not or scarcely inflated
so that the first cell
18 is still small in volume. Accordingly, the frictional
resistance applied to the first cell
18 by the A-pillar trim
36A
is extremely small so that the first cell
18 can be extremely smoothly dragged
out of the trim
36A. In addition, the trim
36A is required to create
a smaller slit through which the airbag
1 is pulled out so that the trim
36A has a simple structure.
In this embodiment, the first cell
18 has a triangular profile of which
one side extends along the A-pillar
31 and communicates with the second
gas passage
22 at an opposing corner of the side along the A-pillar
31.
When the second gas passage
22 is inflated, the first cell
18 starts
to come out of the trim
36A at the corner side thereof. Therefore, the resistance
applied to the first cell
18 by the trim
36A when the first cell
18 is dragged out of the trim
36A is extremely small, thereby allowing
smooth deployment of the first cell
18.
When gas flows into the first gas passage
21 so that the middle portion
of the airbag
1 is inflated downwardly as shown in FIG. 3, the second cell
20a and the cell
23a adjacent to the first gas passage
21 are also pulled by the inflated first gas passage
21 and is thus
dragged out of the trim
36B. Since these cells
20a,
23a
are inflated mainly outside the trim
36B, the movement of the airbag
1 pushing and opening the trim
36B to deploy out of the trim
36B
is also smooth.
In this embodiment, since the cells
23b and
23c are
also pulled by the first gas passage
21 which is already inflated or being
inflated, the cells
23b and
23c are dragged out of
the trims
36B,
36C into the vehicle cabin before the cells start
to be inflated or the cells are inflated a little. The movement of these cells
is also smooth.
Though the triangular first cell
18 is provided only in a front portion
of the airbag
1 along the A-pillar
31 in the aforementioned embodiment,
a triangular first cell may also be provided in a rear portion of the airbag along
the C-pillar
33.
FIG. 5 shows an airbag
1A according to another embodiment having such
a structure. The airbag
1A has triangular cells
18A,
23C formed
in a front portion and a rear portion thereof. At the centers of the cells
18A,
23C, triangular non-inflatable areas
19′,
24′
are formed by line-shaped joints
4′,
4", respectively. The
cells
18A,
23C are defined by line-shaped joints
3′,
3", respectively. The line-shaped joints
3′,
3" are
connected to circular joints
8′,
14′ formed at front
and rear corners of the upper side of the airbag, respectively. A first gas passage
21A is formed between the liner-shaped joints
3′ and
3".
Formed between the line-shaped joints
3′,
3" and a lower part
of a line-shaped joint
2′ extending along the periphery of the airbag
are second and third gas passages
22A,
22B which communicate with
the first gas passage
21A and extend in the longitudinal direction.
The line-shaped joints
3′,
3" are formed in U-like shape.
Formed inside the U-like line-shaped joints
3′,
3" are U-like
line-shaped joints
5′,
5", respectively. Second cells
20A,
23A are formed between the line-shaped joints
3′,
3"
and the line-shaped joints
5′,
5", respectively.
Further, formed inside the line-shaped joints
5′,
5"
are cells
20B,
23B. The airbag
1A is connected at a front
end and a rear end thereof to the A-pillar and the C-pillar via projections
26.
Also in this embodiment, gas from an inflator
17A introduced through
a gas inlet
16A positioned substantially at a middle portion in the longitudinal
direction of the airbag and flows into the first gas passage
21A to start
the inflation of the airbag
1A and to quickly draw out the first cells
18A,
23C from trims of the A-pillar and the C-pillar. Since the cells
18A,
23C are not or scarcely inflated when pulled out, the cells
18A,
23C can be smoothly pulled out through small slits of the trims.
The above embodiments are both illustrative examples of the present invention
and the present invention is not limited to the above embodiments. For example,
the profile and location of the second cell may be changed. Even the profile of
the first cell is not limited to triangle and may be substantially trapezoid, semi-circle,
or square.
Though the line-shaped joint having a shape similar to and smaller than the
first cell is provided inside the first cell and the area inside the line-shaped
joint is non-inflatable portion in the above embodiments, the shape of the line-shaped
joint is not limited to the shape similar to the first cell. Moreover, the non-inflatable
portion may be omitted.
Though the circular joints are provided at ends of the line-shaped joints
for reinforcing areas around ends of the line-shaped joints defining the first
and second cells and the first and second gas passages, the circular joints may
be omitted by connecting an end of a line-shaped joint to a midway of another line-shaped
joint and by connecting ends of line-shaped joints.
Though the first gas passage is disposed substantially at the middle in the
longitudinal direction of the airbag in the above embodiments, the location of
the first gas passage is not limited thereto. Further, two first gas passages may
be provided to be disposed at difference locations in the longitudinal direction
of the airbag. In this case, it is preferable that the airbag is provided along
the upper side of the airbag with a gas distributing means such as a duct having
gas ports which are in communication with upper parts of the respective first gas passages.
Though the gas inlet is disposed substantially at the middle in the longitudinal
direction of the upper side of the airbag in the above embodiments, the location
of the gas inlet is not limited thereto. The inflator to be connected to the gas
inlet may be located at any place such as the roof side rail or the C-pillar of
the vehicle. When the inflator is located in the C-pillar, a duct for introduction
of gas may be connected to the inflator in order to introduce gas from the inflator
into the first gas passage.
Though the head protective airbag is fabricated by joining two sheets together
in the above embodiments, the fabrication of the airbag is not limited thereto.
For example, the airbag may be obtained by using a base fabric which is woven originally
into an envelope shape by a so-called "hollow weaving" or "jacquard weaving" method.
In this case, the first and second cells and the first and second gas passages
are formed inside the airbag by woven joints inside and along the periphery of
the airbag, instead of joining the opposite surfaces of the airbag by the line-shaped
joints to divide the inside of the airbag.
As described above, according to the present invention, a head protective airbag
can be smoothly dragged out of interior members such as trims when a gas generator
of a head protective airbag device is actuated.
The priority application, Japanese Patent Application No. 2002-076617 filed Mar.
19, 2002 is incorporated by reference herein in its entirety.
Given the disclosure of the present invention, one versed in the art would
appreciate that there may be other embodiments and modifications within the scope
and spirit of the invention. Accordingly, all modifications attainable by one versed
in the art from the present disclosure within the scope and spirit of the present
invention are to be included as further embodiments of the present invention. The
scope of the present invention is to be defined a set forth in the following claims.
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