U.S. patent number RE36,587 [Application Number 08/970,779] was granted by the patent office on 2000-02-29 for inflatable seat belt having bag filter.
This patent grant is currently assigned to Takata Corporation. Invention is credited to Tsuneo Chikaraishi, Yoshinori Ohishi, Yoshihiko Tanaka.
United States Patent |
RE36,587 |
Tanaka , et al. |
February 29, 2000 |
Inflatable seat belt having bag filter
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 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 path
from the gas generating device and a buckle to which the tongue is
detachably engaged. The inflatable portion has an elastic
inflatable unit inserted into the envelope part and is inflated and
deployed by introducing the gas generated by the gas generating
device into the elastic inflatable unit via a filter.
Inventors: |
Tanaka; Yoshihiko (Tokyo,
JP), Ohishi; Yoshinori (Ohtsu, JP),
Chikaraishi; Tsuneo (Hikone, JP) |
Assignee: |
Takata Corporation (Tokyo,
JP)
|
Family
ID: |
23026938 |
Appl.
No.: |
08/970,779 |
Filed: |
November 14, 1997 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
269365 |
Jun 30, 1994 |
05466003 |
Nov 14, 1995 |
|
|
Current U.S.
Class: |
280/733;
280/743.1 |
Current CPC
Class: |
A44B
11/2523 (20130101); B60R 21/18 (20130101); B60R
21/2346 (20130101); D04B 1/16 (20130101); D10B
2505/122 (20130101); D10B 2403/0311 (20130101) |
Current International
Class: |
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
|
|
|
|
|
|
|
42 35 338 |
|
Apr 1993 |
|
DE |
|
50-67520 |
|
Jun 1975 |
|
JP |
|
64-83436 |
|
Mar 1989 |
|
JP |
|
6-56001 |
|
Mar 1994 |
|
JP |
|
6-144138 |
|
May 1994 |
|
JP |
|
6-262994 |
|
Sep 1994 |
|
JP |
|
6-262995 |
|
Sep 1994 |
|
JP |
|
Other References
Hall, The Standard Handbook of Textiles, pp. 184-185..
|
Primary Examiner: English; Peter C.
Attorney, Agent or Firm: Foley & Lardner
Claims
We claim:
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 formed over a part of the webbing and
contacting the occupant when the webbing is worn, said inflatable
portion including a cylindrical skirt disposed on one side of the
webbing and formed of a heat resisting material; a filter directly
attached to and completely surrounding the skirt; an elastic
inflatable tube having an elongated shape and completely
surrounding the webbing and the filter containing the skirt, said
elastic inflatable tube having heat resistance and being fixed to
the webbing; and a knitted member in a flat form and connected to
the webbing to cover the entire inflatable tube, said knitted
member having an elasticity in a direction perpendicular to a
longitudinal direction of the webbing;
a tongue fixed to the skirt 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 hot gas to
the inflatable portion through the gas flow path of the tongue,
said hot gas flowing through the skirt and passing through the
filter to lower temperature of the hot gas so that the inflatable
tube is inflated by the gas while the knitted member is expanded by
enlargement of the tube.
2. An inflatable seat belt according to claim 1, wherein said
inflatable portion formed of the skirt, the filter, the inflatable
tube and the knitted member is .[.a.]. laminated .[.and not
folded.]..
3. An inflatable seat belt according to claim 2, wherein said
inflatable portion further includes a .[.non-expandable.]. cover
for covering the knitted member, said cover being sewn by a thread
along the longitudinal direction of the webbing so that when the
inflatable tube is inflated, the thread is torn to allow the
inflatable tube to inflate easily.
4. An inflatable seat belt according to claim 3, wherein said skirt
has a length of about one third of the length of the filter.
5. An inflatable seat belt according to claim 4, wherein said
inflatable portion further includes an end fitting situated inside
the skirt and a caulking fitting situated over the cover to
sandwich the skirt, the filter, the inflatable tube and the knitted
member therebetween, said tongue passing through the end fitting
and the caulking fitting.
6. An inflatable seat belt according to claim 5, wherein said
elastic inflatable tube is made of silicone rubber. .Iadd.
7. An inflatable occupant protection device comprising:
an elongated webbing;
an inflatable member;
a bag filter disposed within the inflatable member which filters
gas flowing into the inflatable member upon inflation thereof;
and
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..Iaddend..Iadd.8. An inflatable occupant protection device
according to claim 7, wherein the inflatable member includes a
skirt disposed within the bag filter..Iaddend..Iadd.9. An
inflatable occupant protection device according to claim 8, wherein
the skirt is formed of a heat resisting material..Iaddend..Iadd.10.
An inflatable occupant protection device according to claim 8,
wherein the fabric member is a knitted fabric member that is easily
expandable in the direction transverse to the longitudinal
direction of the elongated webbing..Iaddend..Iadd.11. An inflatable
occupant protection device according to claim 7, further comprising
a tongue having a gas flow path therein, the tongue being connected
to the inflatable member..Iaddend..Iadd.12. An inflatable occupant
protection device according to claim 11, further comprising 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.13. 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 in a direction transverse to a
longitudinal direction of the elongated webbing; and
disposing a bag filter within the inflatable member, the bag filter
filtering gas flowing into the inflatable member upon inflation of
the inflatable member..Iaddend..Iadd.14. A method for providing
occupant protection according to claim 13, further comprising the
step of disposing a skirt within the inflatable
member..Iaddend..Iadd.15. A method for providing occupant
protection according to claim 14, wherein the step of disposing a
skirt within the inflatable member comprises disposing a skirt
formed of a heat resisting material within the inflatable
member..Iaddend..Iadd.16. A method for providing occupant
protection according to claim 13, further comprising the step of
connecting a tongue to the inflatable member, the tongue having a
gas flow path therein..Iaddend..Iadd.17. A method for providing
occupant protection according to claim 16, 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. . A method for providing occupant protection
according to claim 13, wherein the step of fixing to the elongated
webbing an inflatable member comprises fixing to the elongated
webbing an inflatable member that is covered by a knitted fabric
member that is easily expandable in the direction transverse to the
longitudinal direction of the elongated webbing..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
structural portion formed in an envelope shape which is usually
maintained in a band shape and is inflated, in an accident in a
predetermined form to withstand high temperature 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 in occupant's body, which
restrains the occupant from sudden movement by a deceleration and
an impact in a crash.
Such a seat belt apparatus comprises a webbing as a woven belt made
of a fabric which has approximately a 50 mm width and is formed
according to Japanese Industrial Standard, a retractor (hereinafter
referred to 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 the 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 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 made of a
fabric. The portion is folded like bellows and is banded by a weak
adhesive so as to usually .[.maintain.]. .Iadd.remain .Iaddend.in a
band shape, or the portion is folded in the 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 inflatable
structural 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 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 a
reclining function 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 quite 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 air bag apparatus.
In the inflatable seat belt apparatus mentioned above, the gas
generator operates according to an operation signal from a sensing
unit such as an acceleration sensor sensing an impact at a crash
and the envelope shape inflatable portion is then substantially
instantaneously inflated and deployed in a predetermined form.
Because it is necessary to immediately spout a gas to the
inflatable portion similar to the air bag apparatus, the gas
generator may be a device for generating a compressed gas or
compressed air filled in a compression container such as a
cylinder. The compressed gas may be nitrogen or carbon dioxide gas.
In case of using the compressed air, a small compressor is
generally mounted.
The inflatable portion of the inflatable seat belt apparatus has a
capacity which is about 1/6-1/7 of the air bag apparatus. Further,
the cylinder or the like which is smaller than the air bag
apparatus is enough for the inflatable seat belt apparatus.
However, the inflatable seat belt is necessary to be equipped with
a device for attaching and detaching the cylinder and a device for
preventing the gas from leaking. The gas pressure should be
inspected periodically.
Recently, .[.the.]. most air bag apparatus .[.has the.]. .Iadd.use
a .Iaddend.gas generator (hereinafter, .[.we call.]. "inflator")
which is a device for instantaneously generating a gas by using
.[.a.]. rapid combustion of a compound.
The inflator receives, first, an operational signal from the
acceleration sensor at a crash to act as a trigger for the
electrical squib, and activates an igniter by an electrical
squib.[.;.]..Iadd.. .Iaddend.Then, a propellant burns to rapidly
generate gas.
The propellant may be sodium azide .[.(NAN3).]. (.Iadd.NaN.sub.3)
.Iaddend.which is well known as a propellant and generates nitrogen
gas by combustion.
In the conventional inflatable seat belt apparatus, a thick fabric
is folded, and the inside of the fabric is coated with silicone
rubber to provide high airtightness for the envelope shape portion.
Also, the inflator is provided with a simple filter for cooling the
inside thereof to lower the temperature of the introduction gas, so
that the high temperature gas from the inflator is directly
introduced into the envelope shape portion.
.[.The applicant has already disclosed an invention of the.].
.Iadd.Disclosed in commonly-owned Japanese patent applications are
.Iaddend.inflatable seat belt apparatus, wherein the envelope shape
portion is formed from a knitted textile and has an inflatable unit
made of a rubber tube and situated inside thereof (.Iadd.see
.Iaddend.Japanese Patent .[.Applications.]. .Iadd.Application
.Iaddend.No. 210353/1992, .Iadd.publication no. 6-144138, published
on May 24, 1994; Japanese Patent Application .Iaddend.No.
210355/1992.Iadd., publication no. 6-56001, published on Mar. 1,
1994.Iaddend.). .[.Furthermore, the applicant has already disclosed
an invention of the.]. .Iadd.Disclosed in another Japanese patent
application is an .Iaddend.inflatable seat belt apparatus, wherein
the envelope shape portion is formed from a fabric having
expandable wefts and has an inflatable unit made of a rubber tube
and situated inside thereof (.Iadd.see .Iaddend.Japanese Patent
Application No. 78623/1993.Iadd., publication no. 6-262994,
published Sep. 20, 1994.Iaddend.).
According to the above mentioned inventions, when the occupant
wears the inflatable seat belt apparatus, the envelope shape
portion is maintained in a thin band shape as compared with the
conventional inflatable seat belt apparatus in which the thick
fabric is folded. Furthermore, in an emergency, the envelope shape
portion can be quickly inflated and deployed without fail.
FIG. 1(a) illustrates an example of the inflatable seat belt
apparatus, wherein a shoulder belt is formed of a knitted textile
and has an inflatable unit made of rubber tube and situated inside
thereof.
In this figure, numeral 51 designates a tongue. The tongue 51 has a
gas inlet 54 as an inlet for introducing the gas into a rubber tube
53 arranged in the belt 52. The gas inlet 54 is coupled to a gas
outlet 56a of gas generating means (inflator) 56 situated inside a
buckle 55 when the tongue 51 is engaged with the buckle 55 for
fixing a belt end 52a.
FIG. 1(b) exemplifies a state of a belt 52 inflated and deployed in
a predetermined form. The propellant in the inflator 56 is burned
to generate a reacted gas, and the gas is introduced into the
rubber tube 53 of the belt 52 through the gas inlet 54, so that the
belt is inflated and deployed in the predetermined form.
As the gas is rapidly introduced into the rubber tube 53, the
rubber tube is inflated as shown in the FIG. 1(b). The shape of the
whole inflatable portion is controlled by a knitted textile
structure 57 formed in an envelope shape which covers the rubber
tube 53. The inflatable portion has 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
.[.soften.]. .Iadd.softened.Iaddend..
Because the inflatable portion formed in the 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 as a pre-tensioner which holds the
occupant more effectively.
In the inflatable seat belt apparatus of this kind, the gas spouted
from the inflator is introduced into the tube with a high
temperature and high pressure condition as soon as the gas is
generated.
FIG. 2 is a temperature distribution diagram exemplifying a result
of the temperature distribution within the tube at this stage. The
figure also shows the inflatable portion in an inflated condition
to indicate the relative position.
At this stage, the inside of the tube has a highest temperature at
a tongue portion near the gas inlet as shown in FIG. 2. In the
longitudinal direction L, respective temperatures appear with
introduction of the gas as shown by the dotted lines. The solid
line shows a curve tracing the respective temperatures.
The gas generated by the combustion in the inflator has quite high
temperature. However, because the temperature drops along the
longitudinal direction, the tube works efficiently if it can
withstand the high temperature only for a very short period.
Silicone rubber with a heat resistance has been adapted to the tube
for receiving the high temperature gas to withstand the high
temperature in the tube.
However, many cinders are produced by the combustion of the
propellant of the inflator. The cinder is mainly fine carbon
powder. The cinders are spouted into the tube with the reaction
gas.
Because the cinder has a high temperature and has a large heat
capacity compared with the gas, the cinder harms the rubber surface
of the tube when the cinder collides with the inner surface of the
tube. When the rubber surface is badly harmed, there is a
possibility of making a hole in the tube.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention is to solve the
above mentioned conventional problems and to provide an inflatable
seat belt apparatus having a high safety, wherein a tube of an
inflatable belt portion is not damaged even if the tube is exposed
to high temperature gas.
For overcoming the above mentioned object, this 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 acting
when 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 path from the gas generating
means, and a buckle with which the tongue is detachably engaged,
wherein the inflatable portion has an elastic inflatable unit
inserted into the envelope part and is inflated and deployed by
introducing the gas generated by the gas generating means into the
elastic inflatable unit via a filter.
The elastic inflatable unit is inserted into the envelope part in
the inflatable portion and the filter is inserted into the elastic
inflatable unit. Thus, the inflatable seat belt apparatus is
inflated and deployed by introducing the gas generated by the gas
generating means.
Therefore, the high temperature and high pressure gas can be
lowered and the cinder having high temperature can be collected by
the filter so as to prevent the elastic inflatable unit from
melting and breakage by gluing the cinder discharged with the gas
introduced into the elastic inflatable unit onto the inner surface
of the elastic inflatable unit.
In this case, the filter is preferably a cylindrical bag filter
inserted into the elastic inflatable unit. Thus, the temperature of
the gas can be lowered along the longitudinal direction of the
inflatable portion and the cinder can be collected with a wider
area so as to prevent the filter from binding. Therefore, the
inflatable portion can be inflated and deployed without fail.
Further, the bag filter is preferably formed of a woven fabric of
heat resistant fiber.
Furthermore, the elastic inflatable unit is preferably a silicone
rubber tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) and 1(b) are explanatory drawings showing conditions
that an inflatable seat belt apparatus having an inflatable portion
formed from a knitted textile structure is inflated;
FIG. 2 is a simplified temperature distribution diagram showing a
distribution of gas temperature in the inflatable portion of the
inflatable seat belt apparatus as shown in FIG. 1(a);
FIG. 3 is a simplified structural view showing an inflatable seat
belt apparatus of an embodiment according to the present
invention;
FIG. 4 is a perspective partial view magnifying and exemplifying
the inside of the inflatable portion shown in FIG. 3;
FIG. 5 is a perspective partial view exemplifying the inside of the
inflatable portion when the inflatable seat belt apparatus shown in
FIG. 4 is inflated and deployed;
FIG. 6 is a perspective view showing a fitting structure between a
tongue and an end of the inflatable portion;
FIG. 7 is a longitudinal sectional view showing an arrangement of
the components of the inflatable portion;
FIGS. 8(a) and 8(b) are partial vertical sectional views showing an
end of the inflatable portion near a slip guide side;
FIG. 9 is a cross sectional view showing a simplified structure of
an engaged portion of a buckle according to the present
invention;
FIG. 10 is a longitudinal sectional view showing a releasing
operation of the tongue by a press button of the buckle;
FIG. 11 is an end view showing a front face of the buckle;
FIGS. 12(a) and 12(b) are simplified perspective views showing an
altered example of a bag filter according to the present invention;
and
FIG. 13 is an explanatory drawing exemplifying a gas flow in the
bag filter .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of an inflatable seat belt apparatus according to the
present invention are 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 between.]. 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 fixed to a predetermined
position near the floor between the right and left front seats via
the tongue 3 and has the other end 2b downwardly guided through a
slip guide 5 or a pillar anchor mounted on a pillar P. The pillar
anchor is adjustable in upper and lower directions. The shoulder
belt is thus hung around and from the slip guide 5 to be wound up
in an ELR 6 arranged near the floor.
A lap 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 near the floor of the door side beyond the seat
cushion.
.[.The description will now be made as regard to details.].
.Iadd.Details .Iaddend.of the .Iadd.respective .Iaddend.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 has a through or integral 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 is used. The webbing 10 may be
formed of polyester finished yarn tightly woven by twilling, plain
weaving or the like. The webbing 10 is equivalent to 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 is 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 shape or elongated members are accommodated
overlappingly.
In FIG. 4, numeral 10a shows that the webbing 10 is positioned
within the cover 20. Because of the difference of the functions,
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 fixed to a predetermined position of the inner belt 21 to
maintain the airtightness as shown in FIG. 8(a). Therefore, the
tube 22 is inflated in a long and slender cylindrical shape as 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.is hardly expandable in the
longitudinal direction of the belt (.[.wrap.]. .Iadd.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 cover
the knitted textile member 23 of a cylindrical shape. The knitted
textile member 23 and the cover 20 are firmly sewn together with
the inner belt 21 as shown in FIG. 8(a).
Preferably, a material for the cover 20 does not show the crease in
the belt and is soft to the touch because the cover 20 is a portion
directly touched with the hand of the occupant and directly
contacts with the clothes of the occupant. In this embodiment, a
tricot knit fabric knitted by warps with polyester finished yarns
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 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 after a crash. Therefore, the
inflatable seat belt apparatus can efficiently restrain the
occupant from movement. In this specification, "inflatable portion"
will be denoted instead of a whole set of the inflatable member
hereinafter.
In addition to the embodiment described above, this invention may
be accomplished by the following modified components of the
inflatable 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. The.]. .Iadd.use. A .Iaddend.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, rubber/blended rubber or the
like.
The knitted textile member 23 is constituted by .[.the.]. .Iadd.a
.Iaddend.tubular knitted textile 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 .[.charging.].
.Iadd.changing .Iaddend.a density of weft 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 .[.2.]. .Iadd.two .Iaddend.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 the knitted fabric are sewn together to
make a circular form. .Iadd.Upon inflation, the knitted fabric
expands in a direction transverse to the longitudinal direction of
the webbing 10 to pretension the webbing 10, for example, in a
manner similar to that illustrated in FIGS. 1(a) and 1(b).
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 view for understanding the inside of the
inflatable portion shown in FIG. 4 when the inflatable seat belt
apparatus is inflated and deployed.
As shown in this figure, the tube 22 is inflated by the introduced
gas, and the knitted textile member 23 constituted by the tubular
knitted textile is elongated in the radial direction in a
cylindrical shape. When the predetermined inner pressure is
applied, a portion of the thread sewing 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 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 3 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 (a 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.
Referring to FIG. 6 and FIG. 7, .[.the description will now be made
as regard to.]. details of the fitting structure between the
inflatable portion 25 and the tongue 3 provided with the gas inlet,
.[.and to.]. .Iadd.as well as .Iaddend.a structure of a bag filter
.Iadd.will now be described.Iaddend..
FIG. 6 is a perspective view showing the connecting portion between
the tongue 3 and the inflatable portion 25. In FIG. 6, an 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 easy to
be 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 with a buckle
body of the buckle 4 (not shown). The tongue pipe 33 has a gas path
34 formed inside thereof. The gas from an inflator (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 constituted
of a normal webbing.
FIG. 7 is a longitudinal sectional view showing the inside of the
inflatable portion.
As shown in FIG. 7, each component, i.e. the inner belt 21, the bag
filter 26, the tube 22, the knitted textile member 23 and the cover
20, of the inflatable portion 25 is overlapped to the peripheral
portion of the end fitting 31 coated by a rubber coating 31a to
tightly connect with each other .Iadd.and thereby form a laminate
(i.e., layered) structure.Iaddend.. The caulking fitting 32 having
an inside coated by a rubber coating 32a is fixed to the peripheral
portion of the inflatable portion.
Since the inflatable portion 25 is structured as described above,
the inflatable portion 25 is maintained sealingly at the end 25a
thereof and a break 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.
The structure of the bag filter 26 will now be described referring
to FIG. 7.
The bag filter 26 is a filter formed of a fabric having high air
permeability which is sewn in an envelope form. The filter has
substantially the same width as the width of the inner belt 21 and
is choked at a distal end side thereof. The bag filter 26 is
inserted into the tube 22 and has an end fixed to the tongue 3.
Furthermore, a skirt 27 is inserted into the bag filter and has a
length which is one third of the length of the bag filter 26. The
skirt 27 is cylindrical, and opens at a distal end thereof and is
formed of the same fabric of the bag filter in this embodiment.
The bag filter 26 and skirt 27 are made from heat-resistant fiber
in this embodiment. For example, the heat-resistant fiber may be
aramid fiber. The aramid fiber is well known as a trade mark
Kevlar.TM. fiber and has high stiffness and high elasticity.
Further, the aramid fiber has good heat resistance and good flame
tightness and starts carbonizing at approximately 500.degree. C.,
so that the aramid fiber does not melt and burn even at a high
temperature.
Though the Kevlar.TM. fiber employed in this embodiment is
para-bond aramid fiber, meter-bond aramid fiber may, of course, be
employed in view of its heat resistance. Furthermore, the filter
may be formed of not only a textile fabric but also a non-woven
fabric.
The bag filter 26 is inflated with the gas spouted from the
inflator and is capable of collecting the cinders having
predetermined or .[.more bigger.]. .Iadd.larger .Iaddend.sizes to
the inside thereof because of its air permeability. The tube is
then inflated with the gas passing through the bag filter 26. At
this stage, as the gas temperature is lowered, the bag filter
effectively acts as a filter and a diffuser.
The skirt is overlapped around the tongue to effectively display
its heat resistance while considering the temperature distribution
as shown in FIG. 2.
Though the aramid fiber is employed in this embodiment as described
above, the fiber may be carbon fiber, alumina fiber,
silicon-carbide fiber or glass fiber, each of which has high heat
resistance.
The carbon fiber has an extremely high heat resistance because it
is made by burning and carbonizing organic fiber. Therefore, the
heat resistance of the carbon fiber is expected to withstand
approximately 2000.degree. C. if the carbon fiber is employed as a
diffuser which receives no load as described in the present
invention.
The alumina fiber as an oxide inorganic material has also very high
heat resistance and is convenient as a textile.
FIG. 8(a) is a sectional view showing a structure of an end between
the inflatable portion 25 and the webbing 10, i.e. the inner belt
21 located inside the inflatable portion 25, near a slip guide
side.
As the structure is 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 tube 22 made of silicon rubber is welded or glued to the
inner belt 21 within the knitted textile member 23. The end of the
bag filter 26 described above is located inside the tube 22.
FIG. 8(b) shows a modification of the example shown in FIG. 8(a).
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 at a predetermined position. The inner belt is cut near
the end 22a of the tube 22 where the inner belt 21 is fixed to the
tube 22. Only the cylindrical bag filter 26 having the same
function as described above is accommodated in the tube 22.
In this embodiment, the inflatable portion 25 works as a "webbing"
in a crash or the like where the gas generating means does not
work. The inflatable portion 25 expands slightly in the
longitudinal direction because of the elongating characteristic of
the knitted textile member 23. Therefore, the inflatable portion 25
and the webbing 10 can receive a tensile force of the belt so as to
restrain the occupant properly.
The inflatable portion 25 is inflated in a suitable form as in the
embodiment shown in FIG. 8(a) at a crash so as to restrain the
occupant at the wide area of the inflatable portion 25.
FIGS. 9-11 are explanatory drawings showing embodiments of the
buckle. The buckle 4 supports a tongue pipe 33 and has the gas
generating means. The buckle 4 introduces the produced gas from the
gas generating means through a gas path 34 in the tongue pipe
33.
The "coupling" between the buckle 4 and tongue 3 is achieved by
engaging a tubular groove 33b disposed on the peripheral surface of
a distal end of the tongue pipe 33, to metal balls 47 inserted in
tapered holes of coupling hole 44a formed in the buckle 4. Each of
the metal balls 47 has a portion projecting from the inner surface
of the coupling hole 44a.
In FIG. 9, numeral 41 designates a housing in which a portion of a
flange plate 42 is fixed. The buckle 4 is secured by the flange
plate 42 to the housing 41 near 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. 9 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, tapered.]. .Iadd.Tapered .Iaddend.holes 44b are formed at
a peripheral surface of the buckle body 44 at predetermined
intervals. The metal ball 47 is inserted in each tapered hole 44b
to be able to move from the peripheral surface side of the buckle
body 44 so that a portion of the 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 a
release operation ring 49 biased by a spring 48 in a direction of
the arrow B. Therefore, one portion of the metal ball 47 projects
into the tubular groove 33b disposed on the peripheral surface of
the tongue pipe 33 to press and bear the tubular 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 one
portion of the housing in a direction of the arrow C as shown in
FIG. 10.
The press button 50 is an operational button of non-encircle type
and has a pressing face 50a disposed at an upper front position of
the housing as shown in FIG. 11. Therefore, the occupant can
operate the button 50 by one action.
.[.The description will now be briefly made as regard to a.].
.Iadd.A .Iaddend.mechanism of releasing the tongue 3 from the
buckle 4 .Iadd.will now be described.Iaddend..
As the press button 50 is pressed in the direction of the arrow C
as shown in FIG. 10, 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 slides against a biasing force of
spring 48 in the direction of the arrow C to release the pressure
of the metal ball 47 from the release operational ring 49.
Therefore, the metal balls 47 are released from the tubular 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 push out the tongue pipe 33 from the
inside of the buckle body 44 and then the tongue 3 is released from
the buckle 4.
FIGS. 12(a), 12(b) are explanatory drawings showing modified
filters 26, 26A.
In the embodiment described before, to improve the heat resistance
around the tongue 3 where the temperature of the spouted gas is
high, the skirt 27 is mounted inside of the bag filter 26 as shown
in FIG. 7. However, touch of the belt and feeling when wearing the
belt are bad because the belt has a thick portion by the
overlapping structure. The modifications as shown in FIGS. 12(a)
and 12(b) are the bag filters structured by only one piece.
For the bag filter 26 shown in FIG. 12(a), a textile having
different fabric thickness which is formed of aramid fiber is
employed to vary the performance of heat resistance along the
longitudinal direction. For a portion around the tongue, a thick
fabric 26A which has higher heat resistance is employed in order to
lower the temperature of the diffuser. For the head, a sheer fabric
26B which has lower heat resistance is employed to mainly obtain a
filter effect. It is possible that different kinds of
heat-resistance fibers are combined and sewn. That is, a higher
heat-resistance fiber may be used around the tongue and a sheer
aramid fiber fabric may be used around head.
FIG. 12(b) illustrates an example that a metal film coating such as
aluminum is provided to an inner surface of the bag filter 26 for a
range corresponding to the skirt part. Though the coated range has
non-air permeability, the thermal insulation effect is improved at
the tongue portion. Therefore, the temperature in the tube is
equalized and the highest temperature around the tongue is
lowered.
The range to be coated is preferably set with reference to the gas
flow as shown in FIG. 13.
That is, the shoulder belt, i.e. the tube 22, the inner belt 21 and
the bag filter 26, is curved gently around the tongue to fit to the
body of the occupant D. In this state, an elbow part 26a of the bag
filter 26 is hit directly and intensively by the heat flow when the
gas is spouted from the inflator (not shown). Therefore, the
temperature of the elbow part 26a is raised partially to quite
.Iadd.a .Iaddend.high temperature. Since the bag filter is employed
not to directly provide radiant heat in this embodiment, it is
necessary to deal with such partial and continuous heating.
Therefore, preferably, the elbow part 26a is provided with the
above described coating or .[.2.]. .Iadd.two .Iaddend.sheets
.Iadd.of .Iaddend.textile fabrics are overlapped at this part.
* * * * *