U.S. patent number RE37,280 [Application Number 08/970,827] was granted by the patent office on 2001-07-17 for inflatable seat belt having defined shape.
This patent grant is currently assigned to Takata Coporation. Invention is credited to Tsuneo Chikaraishi, Nobuya Osada, Yoshihiko Tanaka.
United States Patent |
RE37,280 |
Tanaka , et al. |
July 17, 2001 |
Inflatable seat belt having defined shape
Abstract
An inflatable seat belt apparatus is formed of an inflatable
portion which is usually maintained in a band shape and has an
envelope part inflated and deployed in a spindle shape by
introducing a gas generated by a gas generating device, the gas
generating device acting in case of exceeding a predetermined
threshold, a webbing having the inflatable portion extending over
at least a range directly contacting with an occupant, a tongue
fixed to an end of the inflatable portion and having a gas inlet
from the gas generating device inside thereof and a buckle which
detachably engages the tongue. The envelope part is made of a
knitted fabric expanded in the weft direction in a range of
contacting the chest of the occupant when the envelope part is
inflated. The inflatable seat belt apparatus includes an inflation
restricting device for restricting the expansion in the weft
direction besides the range.
Inventors: |
Tanaka; Yoshihiko (Tokyo,
JP), Chikaraishi; Tsuneo (Hikone, JP),
Osada; Nobuya (Kouga-gun, JP) |
Assignee: |
Takata Coporation (Tokyo,
JP)
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Family
ID: |
23026945 |
Appl.
No.: |
08/970,827 |
Filed: |
November 14, 1997 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
269367 |
Jun 30, 1994 |
05465999 |
Nov 14, 1995 |
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Current U.S.
Class: |
280/733 |
Current CPC
Class: |
A44B
11/2523 (20130101); B60R 21/18 (20130101); D04B
1/123 (20130101); D10B 2403/0312 (20130101); D10B
2505/122 (20130101) |
Current International
Class: |
A44B
11/25 (20060101); B60R 21/16 (20060101); B60R
21/18 (20060101); B60R 021/18 () |
Field of
Search: |
;280/733,728.3,730.1,730.2,728.1,729,740,743.1,736 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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50-67520 |
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Jun 1975 |
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JP |
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1-83436 |
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Mar 1989 |
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JP |
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6-56001 |
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Mar 1994 |
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JP |
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6-144138 |
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May 1994 |
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JP |
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6-262995 |
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Sep 1994 |
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JP |
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6-262994 |
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Sep 1994 |
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JP |
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Other References
Hall, The Standard Handbook of Textiles, pp. 184-185..
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Primary Examiner: English; Peter C.
Attorney, Agent or Firm: Foley & Lardner
Claims
What is claimed is:
1. An inflatable seat belt for restraining movement of an occupant
in a vehicle, comprising:
a webbing attached to the vehicle and extending for restraining
movement of the occupant;
an inflatable portion fixed to the webbing and contacting the
occupant when the webbing is worn, the inflatable portion including
an elastic.Iadd., heat-resistant .Iaddend.inflatable tube having an
elongated shape.[.and heat resistance.]. , and fixed to the
webbing; a knitted.Iadd., flat .Iaddend.member .[.in a flat form
and.]. connected at both longitudinal ends to the webbing to
entirely cover the inflatable tube, said knitted member having
elasticity in a direction perpendicular to a longitudinal direction
of the webbing and non-elasticity in the longitudinal direction of
the webbing; and a .[.non-expandable.]. cover for substantially
completely covering the knitted member and having a joining portion
extending along the longitudinal direction of the webbing without
connecting to the knitted member, said joining portion having a
first part corresponding to a chest of the occupant and at least
one second part situated adjacent to the first part, said first
part being weaker than the second part in strength;
a tongue fixed to the inflatable portion and having a gas flow path
therein; and
a buckle attached to the vehicle and engagable to the tongue, said
buckle having a .[.port.]. .Iadd.body .Iaddend.to supply a gas to
the inflatable portion through the gas flow path of the tongue so
that when the inflatable tube is inflated by the gas, the knitted
member expands laterally at the portion corresponding to the first
part while breaking the first part, expansion of the knitted member
being restricted by the second part.
2. An inflatable seat belt according to claim 1, wherein said first
part is sandwiched between two second parts so that a center
portion of the inflatable portion inflates.
3. An inflatable seat belt according to claim 2, wherein said
inflatable portion further includes a filter attached to the gas
flow path of the tongue, said webbing extending throughout the
entire inflatable portion, and said elastic inflatable tube having
an elongated shape and completely surrounding the webbing and the
filter.
4. An inflatable seat belt according to claim 2, wherein said
elastic inflatable tube has a shape corresponding to the webbing
when the gas is not supplied .[.and is made of silicone rubber.].
.
5. An inflatable seat belt according to claim 4, wherein said
.[.inflatable portion.]. .Iadd.tongue .Iaddend.further includes an
end fitting situated inside .[.the.]. .Iadd.a .Iaddend.filter and a
caulking fitting situated over the cover to sandwich the filter,
the inflatable tube, the knitted member and the cover therebetween,
said tongue .Iadd.including a tongue pipe .Iaddend.passing through
the end fitting and the caulking fitting.
6. An inflatable seat belt according to claim 2, wherein said
inflatable portion further includes a filter attached to the gas
flow path of the tongue, said webbing being fixed at one end to the
.[.filter, the.]. inflatable tube.[., the knitted member and the
cover.]. without entirely extending throughout the inflatable
portion.
7. An inflatable seat belt according to claim 6, wherein said
elastic inflatable tube has a shape corresponding to the webbing
when the gas is not supplied .[.and is made of silicone rubber.].
..Iadd.
8. An inflatable seat belt according to claim 4, wherein said
elastic inflatable tube is made of silicone
rubber..Iaddend..Iadd.
9. An inflatable seat belt according to claim 7, wherein said
elastic inflatable tube is made of silicone
rubber..Iaddend..Iadd.
10. An inflatable occupant protection device comprising:
an elongated webbing;
an inflatable member;
a fabric member connected to the elongated webbing to cover the
inflatable member, wherein the fabric member expands in a direction
transverse to a longitudinal direction of the elongated webbing
upon inflation of the inflatable member, thereby pre-tensioning the
elongated webbing; and
a cover disposed over the fabric member, wherein the cover
restricts the shape and volume of the inflatable member after the
inflatable member is inflated and deployed;
wherein the cover has a joining portion extending along the
longitudinal direction of the elongated webbing, the joining
portion having a first part and at least one second part, the first
part being weaker in strength than the second part; and
wherein the joining portion of the cover is not attached to the
fabric member..Iaddend..Iadd.
11. An inflatable occupant protection device according to claim 10,
further comprising a tongue fixed to the inflatable member and
having a gas flow path therein..Iaddend..Iadd.
12. An inflatable occupant protection device according to claim 11,
further comprising a buckle, the buckle being engageable with the
tongue and having a body to supply a gas to the inflatable member
through the gas flow path of the tongue..Iaddend..Iadd.
13. An inflatable occupant protection device according to claim 12,
wherein the inflatable member further includes a filter attached to
the gas flow path of the tongue..Iaddend..Iadd.
14. An inflatable occupant protection device according to claim 11,
wherein the inflatable member is made of a heat resistant
material..Iaddend..Iadd.
15. An inflatable occupant protection device according to claim 14,
wherein the heat resistant material is silicone
rubber..Iaddend..Iadd.
16. An inflatable occupant protection device according to claim 10,
wherein the fabric member is tubular knitted textile
member..Iaddend..Iadd.
17. An inflatable occupant protection device according to claim 16,
wherein the tubular knitted textile member is
plain-stitched..Iaddend..Iadd.
18. A method for providing occupant protection comprising the steps
of:
attaching an elongated webbing to a vehicle;
fixing to the elongated webbing an inflatable member, the
inflatable member being covered by a fabric member which is
connected to the elongated webbing, the fabric member
pre-tensioning the elongated webbing upon inflation of the
inflatable member by expanding the fabric member in a direction
transverse to a longitudinal direction of the elongated webbing;
and
fixing a cover over the fabric member;
wherein the cover restricts the shape and volume of the inflatable
member after the inflatable member is inflated and deployed,
and
wherein the cover has a joining portion extending along the
longitudinal direction of the elongated webbing, the joining
portion having a first part and at least one second part, the first
part being weaker in strength than the second part; and
wherein fixing the cover comprises fixing the cover over the fabric
member without attaching the joining portion of the cover to the
fabric member..Iaddend..Iadd.
19. A method for providing occupant protection according to claim
11, further comprising the step of providing a tongue fixedly
connected to the inflatable member and having a gas flow path
therein..Iaddend..Iadd.
20. A method for providing occupant protection according to claim
19, further comprising the step of providing a buckle for engaging
the tongue, the buckle having a body to supply gas to the
inflatable member through the gas flow path of the
tongue..Iaddend..Iadd.
21. A method for providing occupant protection according to claim
19, further comprising the step of attaching a filter to the
tongue..Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an inflatable seat belt apparatus,
more particularly to an inflatable seat belt, wherein a webbing of
a seat belt apparatus to restrain an occupant has an inflatable
portion formed in an envelope shape which is usually maintained in
a band shape and is inflated, in an accident, in a predetermined
shape with gas .[.spouted.]. from a gas generating means.
Presently, a seat belt apparatus is necessary for a vehicle or the
like as an apparatus .[.for securing.]. .Iadd.to secure .Iaddend.an
occupant's body .[., which.]. .Iadd.. Such apparatus
.Iaddend.restrains the occupant from sudden movement by a
deceleration and an impact in a crash.
Such a seat belt apparatus .[.comprises.]. .Iadd.may comprise
.Iaddend.a webbing .Iadd.such .Iaddend.as a woven belt made of a
fabric which has approximately a 50 mm width and is formed
according to Japanese Industrial Standard.[., to.]. .Iadd.. The
seat belt apparatus may .Iaddend.have a retractor (hereinafter
referred to .Iadd.as an .Iaddend.ELR: Emergency Locking Retractor),
a buckle, a tongue, an anchor and so on.
The ELR winds the webbing by a winding force of a spring and locks
the webbing from withdrawing only at a crash so as to restrain the
occupant. The buckle is mounted on a suitable position near a floor
so that the webbing fits the occupant's body well.
Conventionally, the seat belt apparatus locks the webbing from
withdrawing by the function of .Iadd.the .Iaddend.ELR at a crash to
restrain the occupant from a forward movement.
For improvement in the efficiency of restraining the occupant, each
of U.S. Pat. Nos. .[.3,841,645.]. .Iadd.3,841,654.Iaddend.,
3,865,398, and 3,866,940 discloses a seat belt apparatus in which
the webbing has a portion formed in an envelope shape and is folded
like .Iadd.a .Iaddend.bellows. The portion is provided with a weak
adhesive so as to usually maintain .[.in.]. in a band shape, or the
folded portion is held in .[.the.]. .Iadd.a .Iaddend.band shape by
fastening means such as a fastener, so that in a crash, the portion
formed in the envelope shape is inflated and deployed by .[.a
spouted.]. gas from a gas generator connected to the webbing.
According to the seat belt apparatus having .[.the.]. .Iadd.an
.Iaddend.inflatable portion formed in an envelope shape
(hereinafter, .[.it is called as.]. "an inflatable seat belt
apparatus"), force applied to the occupant can be distributed over
.[.the.]. .Iadd.a .Iaddend.range wider than the conventional
webbing so as to decrease the stress applied to the occupant and a
higher safety efficiency can be provided.
The inflatable seat belt apparatus is effective even for a rear
seat. For mounting an air bag apparatus for an occupant on the rear
seat, the air bag apparatus is generally mounted on the rear side
of the back portion of the front seat. It is necessary that the
front seat structure has a high rigidity for suitably operating the
air bag apparatus for the rear seat to efficiently restrain and
secure the occupant. However, it is difficult to provide the
reclining mechanism having a movable portion to the front seat if
the air bag apparatus is mounted on the rear side of the back
portion of the front seat. Therefore, the inflatable seat belt
apparatus is effective for the rear seat because the inflatable
seat belt apparatus can be independently mounted on the rear seat
and has no restriction such as the above mentioned air bag
apparatus.
In such an inflatable seat belt apparatus, wherein the envelope
shaped portion is folded to form a band shaped belt having a
predetermined width as mentioned above, the folded envelope shaped
portion is piled up to be thickened. Therefore, the belt is hard to
fit the occupant's body during wearing and hard to pass smoothly
.Iadd.through .Iaddend.a slip guide of a pillar anchor.
Accordingly, there is a fear of decreasing the belt wearing rate
because the occupant feels an incongruity during wearing.
Further, the folded portions are glued together and therefore, the
inflatable portion is hard to deploy smoothly even when the
.[.spouted.]. gas is introduced into the envelope shaped portion
during .[.the.]. deployment.
.[.Therefore, the applicant has already proposed an.].
.Iadd.Disclosed in commonly-owned Japanese patent applications are
.Iaddend.inflatable seat belt apparatus which can overcome these
problems (Japanese Patent Application No. 210353/1992,
.Iadd.publication no. 6-144138, published May 24, 1994; and
Japanese Patent Application .Iaddend.No. 210355/1992,
.Iadd.publication no. 6-56001, published Mar. 1,
1994.Iaddend.).
These applications disclose inventions .[.that.]. .Iadd.in which
.Iaddend.the envelope shaped portion .[.is structure by.].
.Iadd.comprises .Iaddend.a knitted fabric member, i.e. a woven
textile member having wefts which expands enough.
According to these inventions, the seat belt apparatus is
maintained in a relatively thin band shape and can inflate and
develop the envelope shaped portion reliably and promptly .[.at.].
.Iadd.in .Iaddend.an emergency.
FIG. 1 (a) shows an example of .[.the .]. .Iadd.an
.Iaddend.inflatable seat belt apparatus, wherein one portion of a
shoulder belt is .[.structured by.]. .Iadd.comprised of .Iaddend.a
cylindrical knitted fabric member. .[.And.]. .Iadd.In this example,
.Iaddend.a rubber tube formed in an envelope shape is inserted into
the cylindrical knitted fabric member.
In this figure, numeral 51 designates a tongue. The tongue 51 has a
gas inlet 53 for introducing gas into the rubber tube in a belt 52
.[.inside thereof.]. . The gas inlet 53 is coupled to a gas outlet
of gas generating means, i.e. gas generator (not shown), connected
inside a buckle 54 when the tongue 51 is engaged with the buckle 54
for fixing a belt end 52a to the vehicle body.
FIG. 1 (b) shows an example of a state where a predetermined gas
pressure is applied to the belt portion of the inflatable seat belt
apparatus structured as stated above.
As shown in this figure, the rubber tube is inflated by the gas
pressure in the tube. .[.And a whole.]. .Iadd.The .Iaddend.shape of
the rubber tube is defined by the envelope shaped knitted fabric
member .[.wrapping.]. .Iadd.covering .Iaddend.the tube and is
inflated in a spindle shape. Because the area of the belt portion
touching the chest and the like of the occupant is increased, an
impact applied to the occupant is softened and the apparatus can
protect the occupant efficiently.
Because the inflatable portion formed in an envelope shape is
radially increased, the length of the belt in a longitudinal
direction is shortened by .DELTA.L. Therefore, the inflatable seat
belt apparatus .[.has a function.]. .Iadd.functions .Iaddend.as a
pre-tensioner so that the occupant is more effectively
.[.retained.]. .Iadd.restrained.Iaddend..
However, the following problems become apparent from various tests
using a model and a real vehicle for the inflatable seat belt
apparatus as mentioned above. The tests are executed by using a
full-sized dummy.
As shown in FIG. 2, the knitted fabric structural portion of the
shoulder belt 52 is effectively inflated and deployed in a
crash.
When the belt tries to restrain the dummy D from movement, the gas
in the tube escapes to a space 52b between the buckle near the
floor and the waist of the dummy D and to a space 52c between a
pillar anchor 55 and the shoulder of the dummy D, so that the
shoulder belt 52 is inflated in a gourd shape. In this state, the
shoulder belt 52 can not be inflated over an enough area at the
important place for catching the chest of the dummy D. This spoils
the merit of using an inflatable structure for the shoulder
belt.
Because the tube is inflated in the whole extent of the
longitudinal direction thereof, the inflation volume becomes large
and then the gas pressure in the tube is hard to .[.be increased.].
.Iadd.increase .Iaddend.. In addition, because the tube can not be
inflated enough in the radial direction thereof, the length of the
belt in the longitudinal direction is not .[.shorted.].
.Iadd.shortened .Iaddend.enough. Therefore, the above mentioned
function as a pre-tensioner does not work effectively.
Furthermore, the above mentioned inflatable seat belt apparatus has
various inconveniences. In the inflatable seat belt apparatus, the
envelope shaped portion of the shoulder belt is also wound in an
ELR mounted in the under portion in the pillar. The belt portion
formed of the knitted fabric is slightly thicker than the belt
portion formed of the fabric textile. Therefore, the ELR should be
exchanged for a special ELR which can accommodate the thick belt
formed of a knitted fabric.
A slip guide is mounted to the pillar anchor to change the
direction of the belt withdrawn .[.form.]. .Iadd.from the
.Iaddend.ELR. The slip guide has a guide opening for the belt. The
width of the guide opening is narrow for preventing the belt from
twisting and turning over. Therefore, it is hard to allow the thick
belt to smoothly pass therethrough.
On the other hand, .[.in case that.]. .Iadd.when .Iaddend.the belt
.[.is formed to have.]. .Iadd.has .Iaddend.a short width, the
occupant feels the belt is undependable. The belt must maintain its
stiffness and .[.its.]. .Iadd.a .Iaddend.form which .[.give
dependence.]. .Iadd.imparts a feeling of dependability .Iaddend.to
the occupant when the occupant uses the belt.
.[.It.]. .Iadd.A suitable design .Iaddend.should .[.be considered
to.]. .Iadd.also .Iaddend.prevent the surface of the knitted fabric
from abrasion.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to overcome the
above mentioned problems of the prior art and to provide an
inflatable seat belt apparatus .[.maintaining.]. .Iadd.that
maintains .Iaddend.a proper inflation shape and an internal
pressure therein when the apparatus restrains the occupant from
movement during deployment.
Furthermore, .[.the.]. .Iadd.it is an object of the invention to
provide an .Iaddend.inflatable seat belt apparatus .Iadd.which
.Iaddend.fits an occupant's body well and has enough durability
even if the apparatus is used repeatedly.
For accomplishing the above mentioned .[.object.].
.Iadd.objects.Iaddend., a first invention provides an inflatable
seat belt apparatus comprising an inflatable portion which is
usually maintained in a band shape and has an envelope part
inflated and deployed in a spindle shape by introducing a gas
generated by gas generating means, the gas generating means
actuating in case of exceeding a predetermined threshold, a webbing
having the inflatable portion extending over at least a range
directly contacting with an occupant, a tongue fixed to an end of
the inflatable portion and having a gas inlet for receiving the gas
from the gas generating means, and a buckle detachably engaging the
tongue, wherein the envelope part is made of a knitted fabric, and
the knitted fabric is expandable in the weft direction in a range
of contacting the chest and around the chest of the occupant when
the envelope part is inflated, while the inflatable seat belt
apparatus includes inflation restricting means for restricting the
expansion in the weft direction besides the range. Therefore, the
inflatable seat belt apparatus can restrain the occupant .[.form.].
.Iadd.from .Iaddend.movement with a wide contacting area around the
chest of the occupant. Further, the pressure in the inflatable
portion can be increased because the volume of the inflation is
minimized and the webbing is shortened .[.certainly.].
.Iadd.reliably .Iaddend.in the longitudinal direction. Therefore,
the function as a pre-tensioner is effectively provided to restrict
the occupant more effectively.
The second invention provides an inflatable seat belt apparatus
comprising an inflatable portion having an envelope part formed
over a range of .[.connecting.]. .Iadd.contact with .Iaddend.an
occupant and usually maintained in a band shape, the envelope part
being inflated and deployed in a rough spindle shape by introducing
a gas generated by gas generating means thereinto in case of
exceeding a predetermined threshold, a webbing having one end fixed
to the inflatable portion and the other end accommodated in winding
means by winding, a tongue fixed to a distal end of the inflatable
portion and having a gas inlet for receiving the gas from the gas
generating means, and a buckle detachably engaging the tongue,
wherein the envelope part is made of a knitted fabric, and the
knitted fabric is expandable in the weft direction in a range of
contacting the chest and around the chest of the occupant when the
envelope part is inflated, while the inflatable seat belt apparatus
includes inflation restricting means for restricting the expansion
in the weft direction besides the range.
Therefore, the inflatable portion can become thinner so that the
inflatable seat belt apparatus becomes useful. As .[.well as.].
.Iadd.with .Iaddend.the first invention, the inflatable seat belt
apparatus can restrain the occupant from movement with a wide
contacting area around the chest of the occupant. Further, the
pressure in the inflatable portion can be increased because the
volume of the inflation is minimized and the webbing is shortened
.[.certainly.]. .Iadd.reliably .Iaddend.in the longitudinal
direction. Therefore, the function as a pre-tensioner is
effectively provided to restrict the occupant more effectively.
In the above inventions, preferably, the inflation restricting
means comprises a cylindrical cloth cover having a connecting
portion extending in the longitudinal direction thereof, the
cylindrical cloth cover being formed to cover the envelope part.
The connecting portion comprises a first part corresponding to the
chest .[.and.]. of the occupant and a second part, the first part
being broken away by a pressure in the envelope part during the
inflation and deployment, and the second part being maintained
without .[.break.]. .Iadd.breaking .Iaddend.even even during the
inflation and deployment. Therefore, the inflation shape and
inflation volume of the inflatable portion during the inflation and
deployment thereof can be easily controlled. In addition, the
envelope part is effectively protected during wearing and so on and
the durability of the belt portion constructing the inflatable
structural portion is improved.
Preferably, the connecting portion is formed by a .[.seaming.].
.Iadd.a seam.Iaddend..
Furthermore, preferably, the envelope part is formed by a tubular
knitted textile.
In the first invention, preferably, the webbing has an end fixed to
the tongue with the inflatable portion and the other end
accommodated in .Iadd.a .Iaddend.winding means .[.by winding.]. ,
the inflatable portion extending over at least a range directly
contacting .[.with.]. an occupant to wrap the webbing .[.as a core
thereof.]. .
In the above mentioned inventions, preferably the inflatable
portion has a tubular inflatable member inserted thereto, the
tubular inflatable member being inflatable by introducing a
gas.
Preferably, the inflation restricting means has an inflation
restricting part disposed on the surface of the tubular inflatable
member, so that an inflation of the envelope part is restricted by
restricting an inflation shape of the tubular inflatable
member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 (a), and 1 (b) are explanatory views showing an example of
inflation shapes of a conventional inflatable seat belt apparatus
having an inflatable member structured by a knitted fabric;
FIG. 2 is a perspective view simply showing a result of tests using
a dummy, wherein the inflatable seat belt apparatus as shown in
FIG. 1 is inflated and deployed;
FIG. 3 is a simplified perspective view showing an embodiment of an
inflatable seat belt apparatus according to a first invention;
FIG. 4 is a perspective partial view magnifying and exemplifying
the inside of the inflatable portion when an occupant .[.usually.].
wears the inflatable seat belt apparatus shown in FIG. 3;
FIG. 5 is a perspective partial view exemplifying the inside of the
inflatable structural portion when the inflatable seat belt
apparatus shown in FIG. 4 is inflated and deployed;
FIG. 6 is a longitudinal sectional view showing a structure of a
slip guide side of the inflatable portion .Iadd.taken along a line
VI-VI in FIG. 4.Iaddend.;
FIGS. 7 (a)-7 (c) are explanatory drawings showing a state of
sewing of a cover of the inflatable portion and a state of the
inflatable portion restricting the inflation shape by the
cover;
FIG. 8 is a perspective view .[.simply.]. showing a result of tests
using a dummy, wherein the inflatable seat belt apparatus of the
present invention is inflated and deployed;
FIGS. 9 (a)-9 (c) are perspective views showing an altered example
of a member for restricting an inflation shape of the inflatable
portion;
FIG. 10 is a plain stitch pattern showing an altered example of a
knitted fabric structure;
FIG. 11 is a perspective view showing a fitting structure between a
tongue and the end of the inflatable portion;
FIG. 12 is a longitudinal sectional view showing a section of the
fitting structural taken along a line XII--XII in FIG. 11;
FIG. 13 is a cross sectional view showing a simplified structure of
an engaged portion of a buckle;
FIG. 14 is a vertical sectional view showing a releasing operation
of the tongue by a press button of the buckle;
FIG. 15 is an end view showing a front face of the buckle;
FIG. 16 is a partial longitudinal sectional view showing a
structure of a slip guide side of the inflatable portion according
to the second invention; and
FIGS. 17 (a)-17 (c) are perspective views showing altered examples
of members for restricting an inflation form of the inflatable
portion according to the second invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of an inflatable seat belt apparatus according to the
present invention is now described referring to the attached
drawings.
FIG. 3 is a simplified perspective view showing a whole structure
of the inflatable seat belt apparatus 1. This figure illustrates
.[.for clarifying.]. relationships among respective components of
the inflatable seat belt apparatus applied to the right side front
seat.
In this figure, numeral 2 designates a shoulder belt. The shoulder
belt 2 has an end 2a to which a tongue 3 is fixed. The shoulder
belt 2 is engaged and fixed to a buckle 4 mounted on a
predetermined position of the floor between the right and left
front seats via the tongue 3. The shoulder belt has the other end
2b downwardly guided through a slip guide 5 of a pillar anchor (not
shown) mounted on a pillar P. The pillar anchor is adjustable in
upper and lower directions. The shoulder belt is thus hung from the
slip guide 5 to be wound up in an ELR 6 arranged near the
floor.
A loop belt 7 has an end 7a fixed to an anchor plate 8 fixed to a
mouthpiece of the tongue 3 and has the other end 7b wound in the
ELR 9 mounted on the floor at the door side beyond the seat
cushion.
.[.The description will now be made as regard to details.].
.Iadd.Details .Iaddend.of the structures of the shoulder belt,
peripheral components of the tongue, and the buckle, respectively
.Iadd.will now be described.Iaddend..
The shoulder belt 2 comprises the end 2b wound and accommodated in
the ELR 6, the other end 2a connected to the tongue 3, and a piece
of webbing 10 as a through member as shown in FIG. 3. In this
embodiment, for the webbing 10, a band shaped belt having a 50 mm
width and a 1.6 mm thickness which is tightly woven by twilling,
plain weaving or the like by using polyester finished yarn .[.is
employed.]. . The webbing 10 is equivalent to one of a conventional
seat belt apparatus. The webbing 10 has a section between an
abdominal region and a right shoulder region which directly touches
the body of an occupant wherein the section has a portion covered
by a cylindrical cover 20 made of a cloth and formed to have a
slight thickness.
In the inside of the portion having the slight thickness, several
kinds of envelope shaped members are accommodated
overlappingly.
In FIG. 4, numeral 10a shows the webbing 10 positioned within the
cover 20. Because of the difference .[.of the functions.]. .Iadd.in
function.Iaddend., this portion of the belt is called an inner belt
21, the portion of the belt which is exposed outside and is wound
into the ELR is called the webbing 10, and these portions are
designated by the different numerals 10 and 21, respectively.
The inner belt 21 is inserted in a flat condition into a tube 22,
formed of a thin film and made of silicone rubber as shown in FIG.
4. The tube 22 made of silicone rubber is cylindrical and has an
end 22a sealingly fixed to a predetermined position of the inner
belt 21 as shown in FIG. 6. Therefore, the tube 22 is inflated in a
long and slender cylindrical shape as a gas is introduced into the
tube 22.
This tube 22 is accommodated in a cylindrical knitted textile
member 23 of flat type which is knitted in a size slightly larger
than the tube 22. In this embodiment, the knitted textile member 23
is constituted by a tubular knitted textile using a polyester
finished yarn (1500 denier). The knitted textile member 23 of the
tubular knitted textile has a characteristic .Iadd.by
.Iaddend.which .Iadd.it .Iaddend.does not expand in the
longitudinal direction of the belt (.[.wrap.]. .Iadd.that is in the
warp .Iaddend.direction of the knitted fabric) and is easily
expandable in a .[.direction (.]. weft direction of the knitted
fabric .[.).]. .Iadd.so .Iaddend.that the circumference of the
cylindrical shape is increased.
The cloth cover 20 as described above is arranged to .[.wholly.].
.Iadd.completely .Iaddend.cover the knitted textile member 23 of a
cylindrical shape, and the knitted textile member 23 and the cover
20 are firmly sewn together with the inner belt 21 as shown in FIG.
6.
Preferably, a material for the cover 20 does not show a crease and
is soft .[.in touching.]. .Iadd.to the touch .Iaddend.because the
cover 20 is a portion directly touched with the hand of the
occupant and directly contacts with the .[.clothe.]. .Iadd.clothing
.Iaddend.of the occupant. In this embodiment, a tricot knit fabric
knitted by warp knitting with a polyester finished yarn is employed
for the cover 20.
The thick portion has the inflatable tube 22 with the inner belt 21
as a core, and the end is connected to the gas generator via the
tongue 3 so as to be inflated and deployed by the gas introduced in
a very short period of time at a crash. Therefore, the inflatable
seat belt apparatus can efficiently restrain the occupant from
movement. In this specification, .Iadd.reference is made to an
.Iaddend."inflatable portion" .[.will be denoted.]. instead of .[.a
whole set of.]. the .Iadd.entire .Iaddend. inflatable member
.[.hereinafter.]. .
In addition to the embodiment described above, this invention may
be accomplished by the following embodiments having modified
components of the inflatable structural portion.
For the tube 22, a rubber material which has high elasticity even
against a rapid inflation and has heat-resistance because the high
temperature gas is filled in the inside of the tube 22 is suitable
for .[.using.]. .Iadd.use.Iaddend.. The material having rubber-like
elasticity may be used for the tube 22. The material may be, for
example, various kinds of thermoplastic elastomer, urethane rubber,
fluorocarbon rubber, blended rubber or the like.
The knitted textile member 23 is .[.the.]. .Iadd.a seamless
.Iaddend.tubular knitted textile of wefts .[.having no seam for.].
forming a cylindrical shape in the above mentioned embodiment. The
stitch may be plain stitch, rib stitch, pearl stitch, interlock
stitch or the like. In this case, the elongation of the knitted
textile member 23 in the weft direction is changeable by
.[.converting.]. .Iadd.altering the .Iaddend.density of knitted
loops .[.into.]. .Iadd.in .Iaddend.the .[.wrap.]. .Iadd.warp
.Iaddend.direction.
The knitted fabric of a flat type is made by plain weave. In this
case, it is possible that two sheets of the knitted fabrics in a
long and slender shape are overlapped and the ends of the knitted
fabrics are sewn together to make a cylindrical form, and that both
ends of one sheet of the knitted fabric are sewn together to make a
circular form.
A cloth employed for the cover 20 may be a plain weave fabric using
a nylon yarn or polyester yarn.
Besides the materials as described above, other material such as a
resin film, an artificial leather or the like is considered to be
employed for the cover if the material satisfies the conditions of
.[.the.]. feel, .[.the.]. stiffness, .[.the.]. persistence and so
on.
FIG. 5 is a perspective partial section view .[.for
understanding.]. .Iadd.illustrating .Iaddend.the inside of the
inflatable portion shown in FIG. 4 when the inflatable seat belt
apparatus is inflated and deployed.
As the tube 22 is inflated by the introduced gas, the knitted
textile member 23 constituted by the tubular knitted textile is
elongated in the radial direction to be inflated in a cylindrical
shape. When the predetermined inner pressure is applied, a portion
of the thread sewing together the cloths of the cover 20 is torn. A
seam 20a of the cover is then opened like a mouth, and the tube 22
covered by the knitted textile member 23 is inflated in a spindle
shape to be forced out from the opening of the seam 20a.
.[.While, because.]. .Iadd.Because .Iaddend.a seam 20b of the cover
20 is sewn firmly at a predetermined range on the pillar anchor
side of the inflatable portion 25 and at a predetermined range on
the tongue side, the inflation of the tube 22 is limited by a cover
portion 20c of the cover 20, so that the cover portion 20c is
inflated only in a long and slender cylindrical form. The diameter
of the cylindrical form is approximately 3.6 cm in this
embodiment.
The length in the longitudinal direction of the belt is shortened
because the inflatable portion 25 is inflated in a spindle shape.
At this point, because the knitted textile member 23 of the
inflatable portion 25 receives a tensile force in the longitudinal
direction of the belt, the inner belt 21 does not receive the
tensile force so that the inner belt 21 is loose.
FIG. 6 is a sectional view showing the structure of an end of the
inflatable portion 25 and the webbing 10 (the webbing 10 is called
the inner belt 21 .[.in case that.]. .Iadd.where .Iaddend.it is
located inside the inflatable portion 25 as mentioned above) near a
slip guide side.
As the structure is not now .[.be.]. described again, the end of
the knitted textile member 23 is integrally glued to the end 20d of
the cover 20 by the adhesive and is firmly sewn to the webbing 10.
The end 22a of the .Iadd.silicone rubber .Iaddend.tube 22 .[.made
of silicone rubber.]. is glued to the inner belt 21 within the
knitted textile member 23 inside of the sewing part.
A cylindrical bag filter 26 is accommodated in the tube 22 to
collect cinders such as carbon powder .[.spouted.]. .Iadd.produced
.Iaddend.with the high temperature reaction gas.
The bag filter 26 is made of a cloth which is closely woven to be
able to collect the high temperature fine cinders and to be able to
pass the gas freely. Since the high temperature cinders are adhered
to the inner surface of the filter, the material for the filter is
preferably a cloth having heat resistance.
.[.The description will now be made as regard to a.]. .Iadd.A
.Iaddend.method for controlling a shape of the inflatable portion
25 fully inflated and the inflatable volume .Iadd.will now be
described.Iaddend..
FIG. 7 (a) is a plan view showing the cloth cover 20 used in this
embodiment. The cloth cover 20 is made by seaming together the ends
of tricot knit fabric having a predetermined size to be a slender
cylindrical shape. In this embodiment, a margin for seaming of the
inflatable portion 25 is approximately 800 mm in whole length and
has a range (A) of approximately 300 mm in length at the tongue
side, a range (B) at the middle and a range (c) of approximately
200 mm in length at a slip guide side. The margin is seamed by a
fine thread (60 denier) along the whole length once.
Further, the range (A) and the range .[.(c).]. (.Iadd.C.Iaddend.)
are seamed by a heavy thread (630 denier) twice. The seam pitch by
the heavy thread is closer than the seam pitch by the fine thread.
That is, the seamed portion 20a of the range (B) is seamed only by
the fine thread. At this stage, the fine thread is so strong that
the thread is not broken as the occupant pulls the seam during
wearing.
In case of using a thinner cloth for the cover 20, another cover
20A is preferably covered over the range (A) besides the cover 20
as shown in FIGS. 7 (a) and 7 (b) to restrict the cloth of a cover
portion 20e of the cover 20 near the tongue 3 from breaking when
the gas is introduced into the tube 22 rapidly.
FIG. 7 (c) is an explanatory drawing showing an example of a state
that the inflatable portion 25 covered by the cover 20 shown in the
same FIG. 7 (a) is inflated and deployed by the spouted gas.
First, an impact sensor senses a rapid deceleration over a
predetermined threshold at a crash or the like and then outputs an
operational signal to the gas generator. Thus, the gas generator
generates the gas rapidly. The gas is then .[.spouted to be.].
introduced into the inflatable portion 25 through the gas inlet of
the tongue 3. The inflatable portion 25 is rapidly inflated in a
long and slender cylindrical shape as a whole. When the gas
pressure in the tube 22 is increased to the predetermined gas
pressure, the seam 20a of the above mentioned cover 20 is broken to
extrude the tubular knitted textile at the range (B) in a spindle
shape. As a result of this, the inflatable portion is formed in a
shape as shown in FIG. 7 (c) as a whole.
Therefore, the inflation volume of the inflatable portion 25 can be
restricted about 1/3 of the inflatable portion without the cover 20
as shown in FIG. 1 which is the same size of the inflatable portion
25. The gas pressure in the inflatable portion 25 is increased
since the amount of the gas generated from the gas generator is the
same, so that the above mentioned function as a pre-tensioner is
exactly provided.
FIG. 8 is a simplified perspective view showing a result of tests
using a full-sized dummy D which is for testing the inflation and
deployment of the inflatable seat belt apparatus according to the
present invention.
According to the inflatable seat belt apparatus covered by the
cover 20 shown in FIG. 7(a), the inflatable portion 25 is inflated
around a chest of the dummy D as the center thereof. At this stage,
at .Iadd.either side of .Iaddend.the chest of the dummy D, the
apparatus can provide .[.the.]. .Iadd.a .Iaddend.wide area touching
the dummy D which is wider by 1.6 times than a seat belt apparatus
having a normal webbing 10. Therefore, the inflatable seat belt
apparatus can protect the occupant securely and softly.
It should be understood that the seam portion and range for
breaking of the cover 20 can be set freely by changing the margin
portion for seaming of the cover.
As apparent from FIG. 8, the inflatable portion 25 is inflated in
the slender cylindrical shape .[.at.]. .Iadd.across .Iaddend.the
chest, so that the inflatable seat belt apparatus can restrain a
portion between the clavicle and the shoulder and a portion between
the waist and the hip of the occupant softly as compared with the
normal webbing.
The inflatable range of the inflatable portion 25 can be controlled
by adjusting the strength for seaming the cover. Thus, the suitable
inflation shape and the reduction of the inflatable volume are
accomplished.
Though the description is made .[.as.]. .Iadd.in .Iaddend.regard to
the seaming by the thread for joining the cover in the above
description, an adhesive strength can be changed by changing the
adhesive surface if the joint is provided by adhesion, or a joint
strength is controlled by a mechanical joining member and thereby
the same effect can be provided.
.[.The description will now be made as regard to altered.].
.Iadd.Modified .Iaddend.examples for restricting the inflatable
range of the inflatable portion 25 instead of the cover 20
.[.referring.]. .Iadd.will now be described in reference
.Iaddend.to FIGS. 9 (a)-9 (c) and FIG. 10.
FIG. 9 (a) shows the knitted textile member 23 constituted by a
tubular knitted textile. The knitted textile member 23 has a
stitched portion which .[.are.]. .Iadd.is .Iaddend.hardened by
.[.impregnated.]. .Iadd.impregnation .Iaddend.of a resin .Iadd.so
as .Iaddend.not to expand even if the tube 22 inserted inside
thereof is inflated.
A resin coating 23c .[.indicating.]. .Iadd.with .Iaddend.a weak
tackiness is provided .[.onto.]. .Iadd.on .Iaddend.the knitted
textile member 23 so that the stitches of the knitted textile
member 23 can not be expanded when the belt is pulled during normal
wearing. As the tube 22 is inflated by the introduced gas and then
the gas pressure is applied, the adhesive of the resin coating
impregnated into the stitches is broken so that the inflatable
portion is inflated promptly. Since .[.the.]. both side portions
23a having strong resin coatings are not deformed and remain as
they are even when the tube is inflated, only the gas path portion
is inflated in a slender cylindrical shape. Also in this altered
example, an inflation shape similar to the state shown in FIG. 8 is
accomplished.
Further, according to the altered example, the inflatable range can
be controlled by the knitted fabric per se and the cover 20 can be
omitted since the stitches do not expand during normal wearing
because of the weak resin coating.
FIG. 9 (b) shows an altered example in which the inserted inner
belt 21 and the end of the tube 22 made of silicone rubber are
welded or glued together to form a gas path 22G and the tube 22 is
inserted into the knitted textile member 23 constituted by a
tubular knitted textile so as to construct the inflatable portion
25. Also in this altered example, an inflation shape similar to the
state shown in FIG. 8 is accomplished because an inflation shape of
the heat sealed or glued side portion 22b of the tube 22 is
restricted.
FIG. 9 (c) shows an altered example in which a reinforcing thread
22c is wound spirally around the end of the tube made of silicone
rubber to restrict the inflation shape of the wound portion. In
this altered example, a polyester finished yarn is employed as the
reinforcing thread 22c and is wound around the periphery of the
tube 22 with a predetermined pitch and fixed to the surface of the
tube by an adhesive or the like. Therefore, the periphery of the
tube 22 is not enlarged even when the gas is introduced
thereto.
At this stage, the inflation shape of the tube 22 can be freely
controlled by changing the winding pitch of the reinforcing thread
22c.
Further, the reinforcing thread may not only be wound around the
surface of the tube 22 already manufactured but also buried in the
tube 22 to be incorporated with the tube 22 as a core during
manufacturing.
FIG. 10 shows an example .[.that.]. .Iadd.in which .Iaddend.the
inflation shape of the inflatable portion 25 is controlled by
changing the stitch of the tubular knitted textile .[.as another
altered example.]. .
FIG. 10 shows an example of .Iadd.a .Iaddend.plain stitched knit
pattern. In such a knitting structure, the .[.warps.]. .Iadd.warp
threads .Iaddend.23e are inserted besides the .[.wefts.].
.Iadd.weft threads .Iaddend.at the same intervals as the courses
(c) of weft knitted loop 23d or proper intervals relative to the
courses (c) so that the inflation shape in the weft direction is
controlled. That is, an expanding amount in the lateral direction
of the knitted fabric member 23 is freely controlled by changing
the number, pitch, size or type of the warp .Iadd.threads
.Iaddend.23e .[.inserted.]. .
It should be understood that the above mentioned method can be
applied to another tubular knitted textile such as rib stitch and
pearl stitch.
.[.The description will now be made as regard to the detail.].
.Iadd.Details .Iaddend.of the fitting structure between the
inflatable portion 25 according to the present invention and tongue
3 having the gas inlet .[.referring.]. .Iadd.will now be described
in reference .Iaddend.to FIG. 11 and FIG. 12.
FIG. 11 is a perspective view showing a connecting portion between
the tongue 3 and the inflatable portion 25. In FIGS. 11 and 12, the
end 25a of the inflatable portion 25 is fixed to cover an end
fitting 31 made of metal which has a flat square section.
Furthermore, the end 25a is fixed firmly by a caulking fitting 32
so as to cover the periphery thereof, so that the inflatable
portion 25 is not easily broken away from the end fitting 31.
The end fitting 31 has a tongue pipe 33 secured to the distal end
thereof. The tongue pipe 33 is inserted and engaged to the buckle
body of the buckle 4 (not shown). The tongue pipe 33 has a gas path
34 formed inside thereof. The gas from gas generating means (not
shown) is introduced into the inflatable portion 25 through the gas
path 34 and the inside of the end fitting 31.
The tongue 3 is integrally structured by a combination of the end
fitting 31, the caulking fitting 32, and the tongue pipe 33 in this
embodiment.
The tongue pipe 33 has a lap belt anchor plate 8 fixed to the
bottom part thereof to secure an end 7a of a lap belt 7 as a normal
webbing.
FIG. 12 is a longitudinal sectional view showing a fitting
structure for the members of the inflatable portion 25 and the
tongue 3.
As shown in FIG. 12, the inner belt 21, the bag filter 26, the rube
22, the knitted textile member 23 and the cover 20, of the
inflatable portion 25 are overlapped to the peripheral portion of
the end fitting 31 coated by a rubber coating 31a to tightly touch
.[.with.]. each other. The caulking fitting 32 having an inside
coated by a rubber coating 32a is fixed to the peripheral portion
of the inflatable portion.Iadd.. .Iaddend.(In FIG. 12, the caulking
fitting 32 is separated.).[...].
Since the inflatable portion 25 is structured as described above,
the inflatable portion 25 is sealingly maintained at the end 25a
thereof and a break off or a breakage of the end fitting 31 is not
possible even if the reaction gas having high pressure is rapidly
introduced into the inflatable portion 25.
FIGS. 13-15 are explanatory views showing an embodiment of the
buckle. The buckle 4 supports fixedly the tongue pipe 33 and has
the gas generating means disposed inside thereof to introduce the
spouted gas form the gas generating means through the gas path 34
in the tongue pipe 33 to the inflatable portion 25.
The "coupling" between the buckle 4 and tongue 3 is achieved by
engaging an annular groove 33b disposed on the peripheral surface
of a distal end of the tongue pipe 33, to metal balls 47 inserted
in .Iadd.respective .Iaddend.tapered coupling holes .[.44a.].
.Iadd.44b .Iaddend.formed on the buckle 4, in which each of the
metal balls 47 has a portion projecting from the inner surface of
the coupling hole 44a.
In FIG. 13, numeral 41 designates a housing in which a portion of a
flange plate 42 is fixed. The buckle 4 is secured to the flange
plate 42 which is fixed to the floor of the vehicle (not shown). In
the housing 41, a gas generator 43 as the gas generating means is
fixed to the flange plate 42. The gas generator 43 is firmly
connected to a buckle body 44 acting also as a gas passing
pipe.
FIG. 13 shows a state of coupling the tongue pipe 33 to the
coupling hole 44a. As shown in the figure, when the tongue pipe 33
is coupled to the coupling hole 44a of the buckle body 44, a tongue
pipe releasing ring 45 is pressed against a biasing force of the
spring 46 by the tongue pipe distal end 33a in a direction of the
arrow A.
.[.While, the.]. .Iadd.The .Iaddend.tapered holes 44b are formed on
a peripheral surface of the buckle body 44 at predetermined
intervals. .[.The metal ball.]. .Iadd.Each of the metal balls
.Iaddend.47 is inserted with allowance for moving from the
peripheral surface side of the buckle body 44 to each of the
tapered holes 44b so that the one portion of .[.the.]. .Iadd.each
.Iaddend.metal ball 47 projects from the inner surface of the
coupling hole 44a. When the tongue pipe 33 is coupled to the
coupling hole 44a, each of the metal balls 47 is pressed from the
peripheral surface side of the buckle body by releasing operation
ring 49 biased by a spring 48 in a direction of the arrow B.
Therefore, one portion of .[.the.]. .Iadd.each .Iaddend.metal ball
47 projects into the annular groove 33b disposed on the peripheral
surface of the tongue pipe 33 to engage the annular groove 33b of
the tongue pipe 33, so that the tongue pipe 33 is coupled and fixed
inside of the coupling hole 44a.
.[.While, release.]. .Iadd.Release .Iaddend.of the tongue pipe 33
is accomplished by pressing a press button 50 disposed on the
housing in a direction of the arrow C as shown in FIG. 14.
The press button 50 is an operational button of a non-circular type
and has a pressing face 50a directed toward an upper front position
of the housing as shown in FIG. 15. Therefore, the occupant can
operate the button 50 by one action.
.[.The description will now be briefly made in regard to a.].
.Iadd.A .Iaddend.mechanism .[.of.]. .Iadd.for .Iaddend.releasing
the tongue 3 from the buckle 4 .Iadd.will now be described in
brief.Iaddend..
As the press button 50 is pressed in the direction of the arrow C
as shown in FIG. 14, a protuberance portion 49a of the release
operational ring 49 is pressed by an operational arm 50b mounted on
the press button 50 in the direction of the arrow C so that the
release operational ring 49 slide against a biasing .[.farce.].
.Iadd.force .Iaddend.of the spring 48 in the direction of the arrow
C to release the pressure of the metal .[.ball.]. .Iadd.balls
.Iaddend.47 from the release operational ring 49. Therefore, the
metal .[.ball.]. .Iadd.balls .Iaddend.47 .[.becomes.]. .Iadd.become
.Iaddend.free so as to release the press fixing of the metal
.[.ball.]. .Iadd.balls .Iaddend.relative to the .[.tubular.].
.Iadd.annular .Iaddend.groove 33b of the tongue pipe 33. As a
result, the tongue pipe releasing ring 45 in the buckle body 44 is
biased by a spring 46 in a direction of the arrow D to press out
the tongue pipe 33 from the inside of the buckle body 44 and then
the tongue 3 is released from the buckle 4.
An embodiment of the second invention is now described referring to
FIGS. 16 and 17.
FIG. 16 is a sectional view showing a sewing portion of the
inflatable portion 25 near the slip guide side corresponding to
FIG. 6 of the first embodiment.
The end of the tubular knitted textile shown in FIG. 16 is
integrally glued to the end 20d of the cover 20 as in FIG. 6 and is
firmly sewed to the predetermined position of the webbing 10. The
end of the tube 22 made of silicone rubber is heat-sealed or glued
to the inner belt 21 (it is .[.also.]. called the inner belt
21.[.;.]. because it is located inside the inflatable portion 25 as
in the first invention.).[...]. The inner belt 21 is cut at a
portion corresponding to the end 22a where the tube 22 made of
silicone rubber is fixed. In the tube 22, only the cylindrical bag
filter 26 for performing the same function as the bag filter as
described in the first invention is accommodated.
In the inflatable seat belt apparatus structured in the manner
according to the second invention, the inflatable portion 25 is
operable as "webbing" at a weak crash which does not .[.causes.].
.Iadd.cause .Iaddend.the gas generating means to work. That is, the
inflatable portion 25 is expanded little in the longitudinal
direction due to the characteristics of the knitted textile member
23 used therein so that the inflatable portion 25 receives a
tensile force of the belt as well as a normal webbing and can
restrain the occupant reliably.
The inflatable portion 25 is inflated in the proper shape at a
crash as in the first invention so as to restrain the occupant for
the wider area of the inflatable portion 25.
Furthermore, the inflatable portion 25.Iadd., otherwise
.Iaddend.structured as mentioned above, .[.has.]. .Iadd.may have
.Iaddend.no inner belt 21, so that the tube 22 made of silicone
rubber may be modified as shown in FIGS. 17 (a)-(c).
FIG. 17 (a) shows an altered example in which the tube 22 is
restricted by heat sealing or gluing except the gas path 22G.
FIG. 17 (b) shows an altered example in which the diameter near the
gas inlet is reduced to approximately the same as the diameter of
the gas path 22G, and the reinforcing thread 22c is then wound
around the periphery of the tube 22.
FIG. 17 (c) shows an altered example in which the diameter near the
gas inlet is reduced to approximately the same as the diameter of
the gas path 22G, and the thickness of this portion is increased
.Iadd.so as .Iaddend.not to inflate during the gas
introduction.
* * * * *