U.S. patent application number 10/023721 was filed with the patent office on 2002-06-06 for seatbelt system having seamless inflatable member.
Invention is credited to Busgen, Alexander, Cross, S. Jay, Morris, Edward Lee JR., Roemke, Lowell William, Walthall, William Lewis.
Application Number | 20020067031 10/023721 |
Document ID | / |
Family ID | 23837138 |
Filed Date | 2002-06-06 |
United States Patent
Application |
20020067031 |
Kind Code |
A1 |
Busgen, Alexander ; et
al. |
June 6, 2002 |
Seatbelt system having seamless inflatable member
Abstract
A passenger restraint system (100) for an occupant of a vehicle
(102) includes an inflatable belt portion comprising a seamless
hollow inflatable textile member that becomes inflated upon the
occurrence of a collision. The inflatable textile member may vary
in size and construction along its length. The belt portion (104,
112) tightens against the occupant's body when the inflatable belt
portion becomes inflated.
Inventors: |
Busgen, Alexander;
(Wuppertal, DE) ; Cross, S. Jay; (Scottsdale,
AZ) ; Morris, Edward Lee JR.; (Phoenix, AZ) ;
Roemke, Lowell William; (Tempe, AZ) ; Walthall,
William Lewis; (Scottsdale, AZ) |
Correspondence
Address: |
Goodrich Corporation
25401 N. Central Avenue
Phoenix
AZ
85027
US
|
Family ID: |
23837138 |
Appl. No.: |
10/023721 |
Filed: |
December 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10023721 |
Dec 21, 2001 |
|
|
|
09462626 |
Dec 20, 1999 |
|
|
|
Current U.S.
Class: |
280/733 ;
280/743.1 |
Current CPC
Class: |
D03D 1/02 20130101; D03D
1/0005 20130101; B60R 2021/23324 20130101; B60R 21/272 20130101;
B60R 21/18 20130101; B60R 2021/23547 20130101 |
Class at
Publication: |
280/733 ;
280/743.1 |
International
Class: |
B60R 021/18; B60R
021/16 |
Foreign Application Data
Date |
Code |
Application Number |
May 11, 1997 |
DE |
DE 19719218.1 |
Mar 26, 1998 |
DE |
DE 19813630.7 |
Claims
What is claimed is:
1. In a combination for protecting an occupant in a vehicle in the
event of a collision involving the vehicle, the vehicle (102)
having a support structure (106, 125) and having a seat (108) for
the occupant with an inboard side and an outboard side and having a
first retainer means (122) at the inner side of the occupant's seat
and having second retainer means (124) at the outer side of the
occupant's seat, a unitary belt (100) including an inflatable belt
portion (104) and a lap belt portion (112), the inflatable belt
portion (104) extending diagonally across the chest of the
occupant, the inflatable belt portion having first and second
opposite ends and being constructed to be attached at the first end
to the support structure (106) in the vehicle (102), the inflatable
belt portion comprising a seamless hollow textile structure (200,
210, 220), the lap belt portion (112) having first and second ends
and being attached at the first end to the second end of the
inflatable belt portion and extending across the lap of the
occupant from the second end of the inflatable belt portion (104),
the second end of the lap belt portion having a coupling member
(116) for coupling to the first retainer means (122) in the
vehicle, the lap belt portion (112) having a second coupling member
at a position near the inflatable belt portion for coupling to the
second retainer means (124) in the vehicle, and means (124, 116)
operatively coupled to the lap belt portion (112) for extending the
lap belt portion upwardly in the direction of the inflatable belt
portion (104) and for providing for a tightening of the lap belt
portion against the lap of the occupant when the inflatable belt
portion becomes inflated.
2. In a combination as set forth in claim 1, wherein the textile
structure (104, 112, 160, 220, 210, 220) is a continuously woven
member that is pleated prior to inflation.
3. In a combination as set forth in claim 1, wherein the textile
structure (104, 112,160, 220, 210, 220) is a continuously woven
member of varying diameter when inflated, the textile structure
having a center portion (204, 214, 225) between first end portions
(201, 211, 221) and second end portions (203, 213, 223), the
inflated diameter of the end portions being less than that of the
center portion, the first end portion being constructed to be
attached to the support structure (106, 125) in the vehicle (102),
and the second end portion being constructed to be attached to the
lap belt portion (112, 160).
4. In a combination as set forth in claim 1, wherein the textile
structure (104, 112, 160, 220, 210, 220) is a continuously woven
member of varying diameter when inflated, the textile structure
having first end portions (201, 211, 221) and second end portions
(203, 213, 223) and a center portion (204, 214, 225), the diameter
of the end portions being less than that of the center portion, the
number of warp ends (205, 216) per unit of textile circumference
decreasing as the diameter of the textile structure increases, the
first end portion being constructed to be attached to the support
structure (106, 125) in the vehicle (102).
5. In a combination as set forth in claim 1, wherein the textile
structure (104, 112, 160, 220, 210, 220) is a continuously woven
member having first end portiosn (201, 211, 221) and second end
portions (203, 213, 223) joined to a center portion (204, 214,
225), at least some of the weft members (206) adjacent the second
end portion being of plastically extensible filamentary material
(202).
6. In a combination as set forth in claim 1 wherein the inflatable
textile structure (104, 112, 160, 220, 210, 220) is a continuously
woven member having a portion (228) that is plastically expansible
in diameter without rupture in response to inflation gas pressure
in excess of a predetermined value
7. In a combination as set forth in claim 6, wherein the inflatable
textile structure (104, 112, 160, 220, 210, 220) has a first end
portion (201, 211, 221) and a second end portion (203, 213, 223)
which are resistant to increase in diameter when inflated in
response to inflation gas pressure in excess of a predetermined
value and a center portion (204, 214, 225) which plastically
expands in diameter without rupture in response to inflation gas
pressure in excess of said predetermined value.
8. In a combination as set forth in claim 6, wherein the inflatable
textile structure (104, 112, 160, 220) has a first end portion
(221) and a center portion (225) which are resistant to an increase
in diameter when inflated in response to inflation gas pressure in
excess of a predetermined value and a second end portion (228)
which plastically expands in diameter without rupture in response
to inflation gas pressure in excess of said predetermined
value.
9. In a combination as set forth in claim 1, wherein the textile
structure (104, 112, 160, 200, 210, 220) is a continuously woven
member of varying diameter, the textile structure having first end
portions (201, 211, 221) and second end portions (203, 213, 223)
and a center portion (204, 214, 225), the diameter of the end
portions when inflated being less than that of the center portion
when inflated, the center portion extending diagonally across the
chest of the occupant.
10. In a combination as set forth in claim 1, wherein the textile
structure (104, 112, 160, 200, 210, 220) is a continuously woven
member of varying diameter, the textile structure having first end
portions (201, 211, 221) and second end portions (203, 213, 223)
and a center portion (204, 214, 225), the diameter of the end
portions when inflated being less than that of the center portion
when inflated, the center portion extending diagonally across the
chest of the occupant and across the outboard side of the neck and
the head of the occupant.
11. In a combination for protecting a human occupant in a vehicle
(102) in the event of a collision involving the vehicle, the
vehicle having a support structure (106, 125) and having a seat for
the occupant with an inboard side and an outboard side, a unitary
belt (100, 160) including an inflatable belt portion (104, 160)
comprising a seamless hollow textile member (180, 200, 210, 220)
extending across the body of the occupant, the inflatable belt
portion (104, 160, 180) having first and second opposite ends
extending between the inboard side and the outboard side of the
seat (108) and being constructed to be attached to the support
structure (106, 125) in the vehicle (102), the construction of the
inflatable belt portion providing for a tightening of the belt
against the occupant when the inflatable belt portion becomes
inflated, and inflator means (10) disposed relative to the first
end of the inflatable belt portion providing gas inflation of the
inflatable belt portion when the vehicle is in a collision.
12. In a combination as set forth in claim 11, wherein the seamless
hollow textile member (180, 200, 210, 220) is a continuously woven
member that is pleated prior to inflation.
13. In a combination as set forth in claim 12, wherein the pleated
textile member (104) is encased in a frangible cover (105) that is
ruptured upon inflation of the pleated textile member.
14. In a combination as set forth in claim 11, wherein the
inflatable textile member (180, 200, 210, 220) is a continuously
woven member which is of varying size along its length when
inflated, the inflatable textile member having first end portions
(201, 211, 221) and second end portions (203, 213, 223) joined to a
center portion (204, 214, 225), the inflated size of the end
portions being less than that of the center portion.
15. In a combination as set forth in claim 11, wherein the
inflatable textile member (180, 200, 210, 220) is a continuously
woven member that is of varying size along its length when
inflated, the number of warp ends (205, 216) per unit of textile
circumference decreasing as the size of the textile member
increases.
16. In a combination as set forth in claim 11, wherein the
inflatable belt portion (104, 160) includes an integrally woven
stiffener (193) comprising larger warp members (194) that contact
the occupant and resist twisting of the inflatable belt portion and
carry most of the load when the belt is tensioned in a
collision.
17. In a combination as set forth in claim 11, wherein the
inflatable belt portion (104, 160, 180, 190) contains at least two
integrally woven chambers (181, 182, 191, 192) that are
inflatable.
18. In a combination as set forth in claim 17, wherein one of the
chambers (181, 191) is first inflated and another of the chambers
(182, 192) is subsequently inflated by gas passing from said one
chamber (181, 191).
19. In a combination as set forth in claim 11, wherein the
inflatable belt portion (104, 160, 180, 190) contains at least two
integrally woven inflatable chambers (181, 182, 191, 192) are
sequentially inflatable.
20. In a combination as set forth in claim 11, wherein the
inflatable textile member (200, 210, 220) is a continuously woven
member that is of varying size along its length when inflated, the
number of weft ends (206) per unit of textile length increasing as
the size of the textile member increases.
21. In a combination as set forth in claim 20, wherein the number
of weft ends (206) per unit of textile length is greater in the
center portion (204, 214, 225) than in the end portions (201, 211,
221, 203, 213, 229) of the inflatable textile member.
22. In a combination as set forth in claim 20, wherein the center
portion (214, 225) includes a greater number of warps (205, 216)
than the end portions (211, 213, 221, 223) of the inflatable
textile member.
23. In a combination as set forth in claim 20, wherein the center
portion (204) includes the same number of warps (205) as the end
portions (201, 203) of the inflatable textile member (200).
24. In a combination as set forth in claim 20, wherein at least
some of the weft members (206) of the center portion (214. 225) of
the inflatable textile member (210, 220) are of plastically
extensible filamentary material (202).
25. In a combination as set forth in claim 11, wherein the
inflatable textile member (210, 220) is a continuously woven member
having a portion (214, 224) that is plastically expansible in size
without rupture in response to inflation gas pressure in excess of
a predetermined value that does not cause substantial plastic
expansion of the remainder of the inflatable textile member.
26. In a combination as set forth in claim 20, wherein the
inflatable textile member (210. 220) has a first end portion (211,
221) which does not substantially increase in size when inflated in
response to inflation gas pressure in excess of a predetermined
value and a second end portion (224) which plastically expands in
size without rupture in response to inflation gas pressure in
excess of said predetermined value.
27. In a combination as set forth in claim 20, wherein the
inflatable textile member (220) has a first end portion (221) and a
second end portion (223) which are resistant to increase in size
when inflated in response to inflation gas pressure in excess of a
predetermined value and a center portion (225, 224) which
plastically expands in size without rupture in response to
inflation gas pressure in excess of said predetermined value.
28. In a combination as set forth in claim 11, wherein the textile
member (180, 200, 210, 220) is a continuously woven member that
varies in size along its length when inflated, the textile member
having first end portions (201, 211, 221) and second end portions
(203, 213, 223) joined to a center portion (204, 214, 224), the
size of the end portions when inflated being less than that of the
center portion when inflated, the center portion extending
diagonally across the chest of the occupant.
29. In a combination as set forth in claim 11, wherein the textile
member (180, 200, 210, 220) is a continuously woven member of
varying size, the textile member having first end poritons (201,
211, 221) and second end portions (203, 213, 223) joined to a
center portion (204, 214, 225), the size of the end portions when
inflated being less than that of the center portion when inflated,
the center portion extending diagonally across the chest of the
occupant and across the outboard side of the neck and the head of
the occupant.
30. In a combination as set forth in claim 11, wherein the textile
member (180, 200, 210, 220) is a continuously woven member that
varies in size along its length when inflated, the textile member
having first end portions (201, 211, 221) and second end portions
(203, 213, 223) joined to a center portion (204, 214, 225), the
size of the end portions when inflated being less than that of the
center portion when inflated, the center portion extending across
the lap of the occupant.
31. In a combination as set forth in claim 30, further including a
coupling member (116) affixed to an end of the belt (112) and a
retainer means (122) in the vehicle (102) for detachably receiving
the coupling member, wherein the inflator means (10) is disposed
within the inflatable belt portion and is electrically coupled to
receive a triggering signal when the belt is coupled to its
retainer means.
32. In a combination as set forth in claim 31, wherein the inflator
means (10) is disposed adjacent the end of the belt to be
detachably coupled to its retainer.
33. In a combination as set forth in claim 31, further including a
retractor (124) for minimizing slack in the belt portion (112, 104)
and for preventing the length of the belt portion from increasing
when a force above a predetermined value is imposed on the belt
portion for increasing the length of the belt portion, wherein the
inflator means (10) is disposed between the retractor (124) and the
end of the belt to be detachably coupled to its retainer means
(122).
34. In a combination as set forth in claim 30, further including
length adjustment and locking means (124) positioned under the seat
(108) operably connected to the lap belt portion (112) for
adjustment of the length of the lap belt portion and for providing
for a tightening of the lap belt portion against the lap of the
occupant when the inflatable belt portion (104, 160) becomes
inflated, wherein the belt extends beneath the seat, and the
inflator means (10) is disposed between the length adjustment means
(124) and the end of the belt to be detachably coupled to its
retainer (122).
35. In a combination as set forth in claim 30, wherein the inflator
means (10) is disposed externally of the inflatable belt portion
(104, 160).
36. In a combination for protecting an occupant in a vehicle (102)
in the event of a collision involving the vehicle, the vehicle
having a support structure (106, 125) and having a seat (108) for
the occupant with an inboard side and an outboard side and having a
first retainer means (122) at the inner side of the occupant's seat
and having second retainer means (124) at the outer side of the
occupant's seat, a unitary belt (100) including a lap belt portion
(112) and an inflatable belt portion (104), the lap belt portion
(112) being disposed to extend across the lap of the occupant and
having a first end for attachment to the first retainer (122), the
lap belt portion having a second end opposite the first end, the
inflatable belt portion (104) extending diagonally across the chest
of the occupant, the inflatable belt portion having first and
second opposite ends and being constructed to be attached at the
first end to the support structure in the vehicle (106), the
inflatable belt portion comprising a seamless hollow textile member
(180, 200, 210, 220), the inflatable belt portion (104) being
attached to the lap belt portion (112) at the second end of the lap
belt portion, means disposed at the second end of the lap belt
portion (112) for coupling to the second retainer (124) and for
guiding the lap belt portion to the inflatable belt portion, means
disposed at the second end of the inflatable belt portion (104) for
attaching the inflatable belt portion to the support structure, and
a retractor (124) disposed relative to the lap belt portion near
the second coupling member for minimizing slack in the lap belt
portion upon attachment of the first coupling member to the first
retainer (122) and for preventing the length of the lap belt
portion from increasing when a force above a predetermined value is
imposed on the lap belt portion for increasing the length of the
lap belt across the lap of the occupant.
37. In a combination for protecting an occupant in a vehicle (102)
in the event of a collision involving the vehicle, the vehicle
having a support structure (106, 125) and having a seat (108)
connected to the support structure (125) for the occupant with a
first side and a second side and having a first retainer means
(122) at the first side of the occupant's seat and having second
retainer means (124) at the occupant's seat, a unitary belt (100)
including an inflatable lap belt portion (112, 160) comprising a
seamless hollow textile member (180, 200, 210, 220), the inflatable
lap belt portion (112, 160) being disposed to extend across the lap
of the occupant and having a first end affixed to a first coupling
member (116) for detachable attachment to the first retainer mean
(122), the lap belt portion (112) having a second end opposite the
first end coupled to the second retainer means (124), guide means
(103) for guiding the lap belt portion (112) from the second side
of the seat to extend across the lap of the occupant, a retractor
(124) disposed relative to the lap belt portion (112, 160) for
minimizing slack in the lap belt portion upon attachment of the
first coupling member (116) to the first retainer means (122) and
for preventing the length of the lap belt portion from increasing
when a force above a predetermined value is imposed on the lap belt
portion for increasing the length of the lap belt across the lap of
the occupant, and inflator means (10)disposed relative to the
inflatable belt portion providing gas inflation of the inflatable
belt portion when the vehicle is in a collision.
38. In a combination as set forth in claim 37, wherein the
retractor (124) and the inflator means (10) are disposed under the
seat (108).
39. In a combination for protecting an occupant in a vehicle (102)
in the event of a collision involving the vehicle, the vehicle
having a support structure (106, 125) and having a seat (108)
connected to the support structure (125) for the occupant with a
first side and a second side and having a first retainer means
(122) at the first side of the occupant's seat and a second
retainer means (103) at the second side of the occupant's seat, a
unitary belt (112) including an inflatable lap belt portion (160)
comprising a seamless hollow textile member (160, 180, 200, 210,
220), the inflatable lap belt portion (160) being disposed to
extend across the lap of the occupant and having a first end
affixed to a first coupling member (116) for detachable attachment
to the first retainer means (122), the lap belt portion having a
second end opposite the first end coupled to the second retainer
means (103, 124), guide means (103) for guiding the lap belt
portion (112, 160) from the second side of the seat to extend
across the lap of the occupant, and a retractor (124) disposed at
the second side of the seat for minimizing slack in the lap belt
portion upon attachment of the first coupling member to the first
retainer means and for preventing the length of the lap belt
portion from increasing when a force above a predetermined value is
imposed on the lap belt portion for increasing the length of the
lap belt across the lap of the occupant, and inflator means (10)
disposed relative to the inflatable belt portion providing gas
inflation of the inflatable belt portion when the vehicle is in a
collision.
40. In a combination as set forth in claim 36, wherein the
inflatable belt portion (160, 180, 200, 210, 200) is integrally
woven with the lap belt portion (160).
41. In a combination as set forth in claim 36, wherein the
inflatable belt portion (190) includes an integrally woven
stiffener (193) that resists twisting of the inflatable belt
portion.
42. In a combination as set forth in claim 36, wherein the
inflatable belt portion (190) includes an integrally woven
stiffener (193) comprising larger warp members (194) that contact
the occupant and resist twisting of the inflatable belt portion and
carry most of the load when the belt is tensioned in a
collision.
43. In a combination as set forth in claim 36, wherein the
inflatable belt portion (160, 180, 190) contains at least two
integrally woven chambers (181, 182, 191, 192) that are
inflatable.
44. In a combination as set forth in claim 43, wherein one of the
chambers (181, 191) is first inflated and another of the chambers
(182, 192) is subsequently inflated by gas passing from said one
chamber (181, 191).
45. In a combination as set forth in claim 37, wherein the
inflatable belt portion (160, 180, 190) contains at least two
integrally woven inflatable chambers (181, 182, 191, 192) are
sequentially inflatable.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a system for, and method of,
providing a seamless inflatable member such as an inflatable bag or
seat belt, in a vehicle and inflating the member to protect an
occupant when a collision involving the vehicle occurs.
BACKGROUND OF THE INVENTION
[0002] Safety of occupants in vehicles is an important concern to
manufacturers of the vehicles and to the occupants of the vehicles.
The manufacturers have disposed seat belts, some partially or
wholly inflatable, and inflatable air bags in the vehicles to
protect the occupants when collisions involving the vehicle occur.
An inflatable member (this term is used herein to describe an air
bag as well as an inflatable belt or an inflatable belt portion)
becomes inflated upon the occurrence of a collision involving a
vehicle to reduce the occupant's velocity and deceleration below
unacceptable rates and to limit the occupant's movement to enhance
the occupant's safety. Many manufacturers have started to provide
inflatable members for occupants of the front driver seat of an
automobile. Most automobile manufacturers now provide 3-point seat
belts which include a shoulder belt portion and a lap belt portion.
Most aircraft passenger seats are now provided with 2-point seat
belts which include only a lap belt portion. The number of points
refers to the number of anchors or retainers that affix the safety
belt system for an occupant.
[0003] Perhaps the most significant consideration in a vehicle
containing an inflatable member relates to the fact that such a
member cannot begin to restrain the occupant's motion during the
vehicle collision until the occupant has moved into engagement with
such member. Air bags that are typically deployed from the
dashboard or steering wheel waste an important portion of the time
and deceleration space available to protect the occupant against
injury. This markedly reduces the occupant's protection from the
level that can be provided if the restraint is initiated before the
occupant has moved within the vehicle after initiation of the
vehicle collision.
[0004] Non-inflatable seat belts now in use suffer from certain
significant disadvantages. For example, although certain selected
designs of seat belts can, through the use of pre-tensioning
devices, begin a restraint of the occupant earlier than the
restraint provided by an air bag deployed from the dashboard or
steering wheel, such belts do not provide for control of the
occupant's head motion. This shortened deceleration time, however,
has caused markedly higher decelerations and loadings, at least of
the occupant's head, and has produced less than desirable results
from the standpoint of injury thereto.
[0005] Seat belts are also often of narrow physical construction
and thus have not provided for the distribution of the restraining
loads over wide areas of the occupant's body. This has resulted in
unnecessarily high loads being imposed upon the occupant over the
limited portion of the occupant's body in engagement with the seat
belt when a collision involving the vehicle occurs. Additionally
such belts have possessed an elongation that, in many situations,
has allowed the head of an occupant to strike the steering wheel or
the dashboard when the occupant has been seated in a front
seat.
[0006] Furthermore, the spooling out of the webbing material in the
seat belt and the stretching of the seat belt have contributed to
an increased duration of the unrestrained motion of the occupant
before any effective restraint. This has meant that the motion of
the occupant has had to be brought to a stop in a shorter time than
would have been possible if the seat belt had not elongated. This
has contributed to the production of undesirably high rates of
motion and deceleration on the occupant during the restraint
imposed by the seat belt on the movement of the occupant.
[0007] Use of inflatable seat belts of the types known in the prior
art does not overcome all of the deficiencies and disadvantages
discussed above. Many prior attempts at eliminating these
deficiencies and disadvantages with inflatable belts have included
seat belts with a pair of inflatable sections within the belt (one
for the shoulder belt portion, the other for the lap belt portion)
and have additionally required the inflation of these sections to
be accomplished by larger than desirable inflators. Many previous
attempts at producing satisfactory inflatable belts have also
resulted in serious problems with storing the pair of inflatable
sections in the vehicle and have required these inflatable sections
to occupy areas that interfere with entrance and egress of the
occupant respectively into and from the vehicle.
[0008] The deficiencies and disadvantages of many prior art
inflatable seat belts have also required the inflators to be
positioned at the releasable coupling member and the retainer to be
positioned at the sides of the seats. This duality of inflatable
sections has caused many significant problems. One of these has
been that the inflatable gases have had to pass through conduits
located at the buckle attachment point of the belts that are in
themselves releasable. This makes the belts and the inflator
difficult to package and to operate.
[0009] The inflatable belts with dual inflatable sections have had
to be attached to mechanisms which allow for variable lengths of
the belts to be deployed due to variable sizes and positions of the
occupants within the vehicle. This has required the inflator to be
located at the buckle location with the aforementioned deficiencies
or has required the heavy mass of the inflator to be contained
within the inflatable sections of the seat belts. Furthermore, the
duality of inflatable sections has required additional inflators,
squibs, wiring and the like to be used since both of the inflatable
sections in the pair have had to be simultaneously inflated.
[0010] Most inflatable seat belts known in the prior art have other
significant deficiencies and disadvantages. For example, they do
not adequately protect the occupant's neck and head in a side
collision. Furthermore, they also do not adequately protect the
occupant's lower extremities. This results from the fact that the
front seat occupant's lower extremities tend to slide forward
against the instrument panel at the time of the collision while the
occupant in the rear seat tends to slide against the rear of the
front seat. This "submarining" has caused the occupants to incur
injuries to the lower extremities.
[0011] The inflators associated with most prior inflatable seat
belts have operated in an inefficient thermodynamic manner, and
thus have required relatively large amounts of pyrotechnic
materials to be provided in the inflators so that the size and
weight of the inflators have had to be increased to undesirable
proportions. The amount of the pyrotechnic material required in
most of the inflators of the prior art has been roughly between
fifty percent (50%) to one hundred percent (100%) more than is used
in the preferred inflator of this invention. As a result,
acceptable packaging of most prior art inflatable belts and the
inflator within a vehicle has been precluded.
[0012] The configuration and composition of the combustible
materials used in most existing inflators have also produced
relatively slow inflation systems. These slow inflation systems,
while useful for air bags, have not been useful for inflatable seat
belts since such restraints must deploy in less than one fourth of
the time for the deployment of a typical air bag, to be effective,
particularly to provide occupant protection from side impacts. The
deceleration distance of a vehicle involved in a side collision and
the time interval between the initiation of the side impact against
the vehicle and the striking of the occupant against an interior
vehicle surface are greatly reduced relative to the distance and
time for a front impact.
[0013] The combustible materials for some of these known systems
have also required filters to collect the solid particulates that
are produced in operation. Other known systems have utilized
pyrotechnic grains of such size that grain fracture and cracking
have occurred and have caused variations in the combustion surface,
thereby detrimentally affecting the burning rates within the grains
and hence the inflation time Furthermore, when large grains have
been utilized with slow burning rates, the variations in
performance over the range of operating temperatures have been
undesirably large, resulting in variations in protection. For
example, assuming a 40-50 millisecond function time, the changes in
the burning rate of the pyrotechnic material have caused the
function time of the inflator to vary by approximately .+-.20% when
the temperature has been varied between 175.degree. F. and
-65.degree. F. This considerable percentage change in the burning
rate has produced a change in overall function time of
approximately 15-20 milliseconds, an appreciable portion of the
time available to an air bag to decelerate the movement of the
occupant, given that a typical frontal impact of an automobile
lasts only about 120 milliseconds.
BRIEF DESCRIPTION OF THE INVENTION
[0014] This invention provides a system which overcomes the above
disadvantages and deficiencies. It comprises a seat belt combining
a seamless hollow inflatable belt portion disposed across and
adjacent the occupant's body which becomes tightened against the
occupant's body when the inflatable portion becomes inflated.
"Hollow" as used herein in reference to a textile structure means
that such structure is capable of being inflated. In a first
preferred embodiment, it comprises a 3-point seat belt combining a
seamless generally tubular inflatable shoulder belt portion
disposed across and adjacent the occupant's chest, neck and head
and an interconnected lap belt portion which becomes tightened
against the occupant's lap when the inflatable portion becomes
inflated. In a second preferred embodiment, it comprises a 2-point
seat belt having a seamless generally tubular inflatable belt
portion disposed across and adjacent the occupant's lap which
becomes tightened against the occupant's lap and extends upward
toward the occupant's chest when the inflatable portion becomes
inflated. Either of these enhanced restraints prevent the occupant
in a front seat from sliding against the instrument panel or the
steering wheel at the time of vehicular impact, thereby protecting
against injury to the occupant's knees and lower extremities.
Either of these enhanced restraints also prevents the occupant in a
rear seat from sliding against the back of a front seat.
[0015] Furthermore, in the first embodiment that includes an
inflatable shoulder belt portion, when inflated, the inflatable
generally tubular belt portion shortens in effective length and
displaces away from the chest of the occupant to provide, in
combination, pretensioning of the inflatable belt portion, load
distribution and a support cushion for the head in frontal
collision. Additionally, by passing the inflatable belt portion
across the shoulder and alongside the head, the inflatable
generally tubular belt portion protects the occupant's neck and
head from injury due to side impact.
[0016] An suitable inflator which responds almost instantaneously
when a collision involving the vehicle occurs is described in WO
97/23367 published Jul. 3, 1997, entitled "Inflatable Seat Belt
System", naming Donald J. Lewis as inventor, which is incorporated
herein by reference. For example, the inflator provides for the
inflation of the inflatable belt portion in approximately ten
milliseconds (10 ms) after being triggered by the vehicle
collision. This is enabled in part by the use of a small pressure
volume of approximately two (2) cubic inches in the inflator. This
inflator is adapted for use with small particles of a pyrotechnic
material, which provide a large surface that enhances the burning
rates of such particles to provide for gas generation rates up to
approximately ten (10) times greater than that of the inflators of
the prior art. Furthermore, the relatively small amount of the
pyrotechnic material in this inflator produces a minimal amount of
any noxious by-products or noxious smells. This inflator is further
advantageous in that all of the components in the inflator are
disposed within a housing and in that a gas in the housing flows
through a short outlet directly into the inflatable belt portion to
inflate the inflatable belt portion almost instantaneously after
triggering by the vehicle collision.
[0017] The gas flowing through the outlet of the inflator inflates
an inflatable belt portion disposed across the occupant's body and
attached to a vehicle support structure (e.g. a pillar behind the
occupant's seat, the floor or a structural seat affixed to the
vehicle support structure), thereby protecting the occupant's
body.
[0018] The inflatable belt portion of this invention may be
integrally formed as by weaving to a webbing defining the remainder
of the belt portion, or attached as by multiple stitching to
webbing defining the remainder of the belt portion. Some of this
stitching may be configured to become progressively, but not
completely, detached to dissipate the forces imposed on the
inflatable belt portion when the inflatable belt portion becomes
inflated. Where the inflatable belt portion is disposed diagonally
across the chest of the occupant and is joined to a lap belt
portion, the lap belt portion is preferably arranged to slideably
extend through an opening in a coupling member adjacent the
inflatable belt portion and laterally across the occupant's
lap.
[0019] In such an arrangement the lap belt portion becomes
tightened against the occupant's lap when the inflatable belt
portion becomes inflated. The lap belt portion is removably
attached as by the coupling member to a retainer at the inner side
of the seat. When the coupling member is detached from the
retainer, the lap belt portion becomes disposed (e.g. wound) on a
retractor to dispose the inflatable belt portion near the outboard
seat side between the support structure (e.g. the pillar behind the
driver's seat) and the retractor. The occupant can then enter and
exit the vehicle without encumbrance. Alternatively, the retractor
for the lap belt portion may be connected to the seat itself, and
the seat attached to a vehicle support structure, e.g. the floor or
frame of the vehicle.
[0020] The inflatable belt portion is preferably enveloped within a
cover made from any suitable material; for example, a polyester or
a nylon. The cover may be made from a single piece of material
attached at Its opposite ends as by stitching to define a flattened
cylinder enveloping the inflatable belt portion. The cover
stitching progressively separates as the inflatable belt portion
becomes progressively inflated in a direction away from the
inflator. The cover is advantageous in that it may designed to
assist in providing for a controlled inflation of the inflatable
belt portion in a direction away from the inflator. It also
minimizes degradation of the material forming the inflatable belt
portion as from ultraviolet light and protects the inflatable belt
portion from degradation as from chafing against the occupant. A
stiffener may be disposed in the cover against the inflatable belt
portion to prevent the inflatable belt portion from twisting.
Alternatively, the cover may be made from a frangible fabric
material designed to burst open as the inflatable belt portion is
inflated. Alternatively, the inflatable belt portion may contain an
integral stiffener to prevent the inflatable belt portion from
twisting. The cover may extend beyond the inflatable belt portion
to define the remainder of the belt portion in place of standard
webbing.
[0021] A switch may be disposed in the retainer in an open position
When the coupling member is disposed in the retainer, the switch
becomes closed. The switch is included in an electrical circuit
which is operative to initiate the combustion of the pyrotechnic
material within the inflator, upon the occurrence of a collision
involving the vehicle, when the switch is closed. In this way, the
inflatable belt portion can become inflated upon the occurrence of
a collision involving the vehicle only when the inflatable
restraint system of this invention is connected to protect the
occupant's body. This importantly avoids unnecessary deployment and
attendant replacement costs of repairing a vehicle after a
collision.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In the drawings:
[0023] FIG. 1 is a sectional view of an inflator suitable for use
with the invention, including a frangible container holding
particles of a pyrotechnic material and including a housing
enveloping the container and holding a gas, for producing
thermodynamic energy for inflating an inflatable member such as an
inflatable belt portion in a vehicle such as an automobile or
aircraft.
[0024] FIG. 2 is a sectional view similar to that shown in FIG. 1
but shows the inflator after the opening of the container as a
result of a partial combustion of the particles of the pyrotechnic
material in the container and further schematically shows the
continued combustion of the pyrotechnic particles in the
housing.
[0025] FIG. 3 is a schematic fragmentary perspective view of a
vehicle including a unitary belt, comprising an inflatable shoulder
belt portion and a non-inflatable lap belt portion, adapted to
restrain the movements of an occupant seated in the vehicle in the
event of a collision involving the vehicle.
[0026] FIG. 4 is a schematic fragmentary side elevational view of
the vehicle and the occupant seated in the vehicle and shows the
disposition of the inflatable shoulder belt portion and the lap
belt portion after the inflation of the inflatable belt
portion.
[0027] FIG. 5 is a fragmentary perspective view of the unitary
belt, including the inflatable shoulder belt portion and the lap
belt portion, illustrating the attachment of the inflatable belt
portion and the lap belt portion by an arrangement of stitches
adapted for dissipating the stresses produced in the inflatable
belt portion when the inflatable belt portion becomes inflated.
[0028] FIG. 6 is a fragmentary sectional view taken substantially
on the line 6-6 of FIG. 5 and shows in additional detail the
stitching attaching the inflatable belt portion and the lap belt
portion to form the unitary belt, as well as the folding of the
inflatable belt portion to produce a minimal stress on the
inflatable belt portion when the inflatable belt portion becomes
inflated.
[0029] FIG. 7 is a fragmentary view showing in additional detail
the stitching also shown in FIGS. 5 and 6 and illustrating the use
of the seat belt stitching in the area where the inflatable belt
portion remains folded even after inflation, this stitching being
used to transmit loads from the inflatable belt portion to the lap
belt portion.
[0030] FIG. 8 is a front elevational view of a seated occupant and
shows the unitary belt, including the inflatable shoulder belt
portion and the lap belt portion, in solid lines with the
inflatable belt portion and the lap belt portion restraining the
occupant, while showing the inflatable belt portion in broken lines
with the inflatable belt portion and the lap belt portion in a
non-restraining stowed position.
[0031] FIG. 9 is a sectional view of the inflatable belt portion
and a cover enveloping the inflatable belt portion and is taken
substantially on the line 9-9 of FIG. 5.
[0032] FIG. 10 is a side elevational view of a hollow textile
having a cavity of varying diameter.
[0033] FIG. 11 is a side elevational view of a hollow textile
having a cavity of varying diameter including warp members that
float over the region of smaller diameter.
[0034] FIG. 12 is an end view schematically depicting production of
a hollow textile having a cavity.
[0035] FIG. 13 is a fan-shaped weaving guide for spreading and
contracting the spacing of the warp members.
[0036] FIG. 14 is a stitching pattern for joinder of the inflatable
belt portion and another belt portion to form a unitary belt.
[0037] FIG. 15 is a side elevational cutaway view of an inflatable
belt including a three-layer seamless hollow textile structure.
[0038] FIG. 16 is fragmentary perspective view of an inflatable
belt including a three-layer seamless tubular textile
structure.
[0039] FIG. 17 is a schematic view of a weaving pattern for an
inflatable textile structure, the pattern being visible when the
textile structure is severed parallel to the warp direction.
[0040] FIG. 18 is a schematic view of a weaving pattern for an
inflatable textile structure, the pattern being visible when the
textile structure is severed perpendicular to the warp
direction.
[0041] FIG. 19 is a side elevational view of a seamless inflatable
textile (shown in its inflated state) of varying diameter.
[0042] FIG. 20 is a side elevational view of a seamless inflatable
textile (shown in its inflated state) for an inflatable belt
system.
[0043] FIG. 21 is a fragmentary front elevational view of a seated
occupant and shows another embodiment of a unitary belt, including
the inflatable belt portion as the lap belt portion restraining the
occupant.
[0044] FIG. 22 is a side elevational view of a seamless inflatable
textile (shown in its inflated state) for an inflatable belt
system, in solid lines at normal inflation pressure, and in dashed
lines after exposure to excess internal gas pressure.
[0045] FIG. 23 is a schematic view of an apparatus for weaving a
seamless hollow textile structure.
DETAILED DESCRIPTION OF THE INVENTION
[0046] The invention will first be described in reference to the
unitary belt indicated generally at 100 (FIGS. 3 and 4).
Thereafter, the invention will be described in reference to the
unitary belt indicated generally at 160 (FIG. 21).
[0047] One embodiment of an apparatus (an inflator) for inflating
an inflatable member such as an inflatable belt portion is
generally indicated at 10 in FIGS. 1 and 2. In the embodiment of
the inflator 10 shown in the drawings, a housing 12 is provided.
The housing 12 may be made from a material with a low thermal
conductivity to serve as a pressure vessel for holding a gas,
preferably an inert gas such as nitrogen, helium or argon. Argon is
the preferred gas. The gas may be inserted into the housing 12
through a hollow pin 14 which may be closed as by welding after the
gas has been inserted into the housing.
[0048] The housing 12 may be crimped as at 16 to hold an insert 18
preferably having a low thermal conductivity. The housing 12 and
the insert 18 may be formed from a metallic material preferably of
a tow thermal conductivity or from a material with an interior
surface coating of a low thermal conductivity. The housing 12 and
the insert 18 may also be formed from an epoxy, fiber glass, nylon
or a number of other suitable materials having a low thermal
conductivity, all which are well known in the art. A ring 19 is
disposed in the housing 12 adjacent the crimp 16 to provide a seal
for preventing gas leakage from the housing.
[0049] A switch 20 may be disposed in the insert 18. A diaphragm 22
may be pressed against the switch 20 when the pressure of the gas
in the housing 12 exceeds a predetermined value. When the pressure
of the gas in the housing 12 becomes less than such predetermined
value, the diaphragm 22 becomes displaced from the switch 20. The
switch 20 then becomes closed to illuminate a light on the
instrument panel or display panel (not shown) at the front of the
occupant compartment in the vehicle, thereby indicating that the
inflator 10 is not operative. The operation of the switch 20 may
provide a signal to associated electronic circuitry. This signal
provides an indication that the inflator 10 is in a defective
state. Such associated circuitry is believed to be known to a
person of ordinary skill in the art.
[0050] The inflator 10 includes a suitable squib (also known as an
initiator or igniter), which may be constructed as follows. A plug
26 may be made from a material having a low thermal conductivity.
Preferably the plug 26 has the same composition as the material of
the insert 18. Connector pins 24 extend into the plug 26. The
connector pins 24 are connected electrically to a bridge wire 28.
The bridge wire 28 is preferably coated or in direct juxtaposition
with a first firing compound 29 which is selected to appropriately
interface electronically and thermally with the electro-thermal
characteristics of the bridge wire 28 so as to provide the desired
ignition of particles of a pyrotechnic material 30. The bridge wire
28 and the first firing compound 29 are believed to be known in the
art. The particles of the pyrotechnic material 30 are disposed
within a frangible container 32 in juxtaposition to the first
firing compound 29. The plug 26 electrically isolates the connector
pins 24, one from the other, to prevent electrical shorting. The
burning time of the pyrotechnic material 30 may be between
approximately one millisecond (1 ms.) and approximately thirty
milliseconds (30 ms.) and is preferably between approximately two
millisecond (2 ms.) and approximately five milliseconds (5 ms.),
depending upon the application.
[0051] The combustible or pyrotechnic material 30 may constitute
relatively small particles or granules with a size in the range of
approximately 0.010 inches to approximately 0.060 inches The
particles may typically have physical dimensions of approximately
0.050 inch in diameter and approximately 0.20 inch thick or
physical dimensions which are roughly spherical and granular with a
sixteen (16) mesh size.
[0052] Material 30 may illustratively constitute particles of a
material designated as UPCo 302 or UPCo 718 by Universal Propulsion
Company, Phoenix, Ariz., USA. The particles of the pyrotechnic
material 30 may comprise a mixture of different sizes to control
the time for the combustion of the combustible material. When used
in the quantities required for the inflator 10, the material 30 has
properties of providing by-products when partially combusted, or
end products when fully combusted, that are environmentally safe
and that do not produce offensive or noxious smells when used in
the small quantities associated with the inflator 10. The term
"environmentally safe" as used herein is meant to indicate that the
by-products and end products from the combustion of the pyrotechnic
material 30 do not injure the occupant or damage the vehicle or the
atmosphere.
[0053] The housing 12 may be crimped as at 31 and a ring 34 may be
provided at the crimp to seal the housing to a manifold 36. The
ring 34 may be affixed to the housing 12 by well-known means other
than a crimp. The manifold 36 may be made from a material having a
low thermal conductivity and may preferably correspond in
composition to the insert 18 and the plug 26. A rupturable
diaphragm 38 may be disposed across an opening 40 in the manifold
36 to isolate the opening from the housing 12 until the diaphragm
becomes ruptured. It will be appreciated that other means than the
diaphragm 38 may be used to isolate the housing 12 from the opening
40, and to provide a communication between the housing and the
opening when the gas in the housing expands. For example, a
spring-biased pop-off valve may be used instead of the diaphragm
38.
[0054] The opening 40 communicates with a conduit 42 extending from
the manifold 36. The conduit 42 is preferably disposed fixedly in
the manifold 36 as by a pin 44 or may be rotatably affixed as by a
snap ring or by other means known in the art. Alternatively, the
conduit 42 may be capable of a relative rotation about its axis to
assist in providing the most desirable position for inflating an
inflatable belt portion 104 (FIG. 4) as the inflatable belt portion
passes over the occupant's body. The conduit 42 communicates with
the inflatable belt portion 104 (FIG. 4). It will be appreciated
that the conduit 42 may be omitted if the opening 40 is intended to
communicate directly with the inflatable belt portion 104, such as
when the inflator is disposed within the inflatable belt portion
(FIG. 21).
[0055] When a collision involving the vehicle occurs, an electrical
signal passes through the connector pins 24 to the bridge wire 28.
This may be accomplished in a manner well known in the art. The
bridge wire 28 then becomes heated to ignite the first firing
compound 29 which in turn ignites particles of the combustible
material 30. The frangible container 32 becomes opened or ruptured
by the heat generated from the combustion of the particles of the
combustible material 30.
[0056] Rupture of the container 32 occurs after a relatively short
period of time such as approximately one millisecond (1 ms). After
the rupture of the container 32, the partially combusted particles
of the pyrotechnic material 30 pass into the housing 12 where such
particles continue to combust. This combustion occurs for a
relatively short period of time such as approximately two to five
milliseconds (2-5 ms). As shown schematically in FIG. 2, the
particles of the pyrotechnic material travel in a direction away
from the container 32 toward the opening 40 and combust as they
travel in this direction. This causes the particles of the
pyrotechnic material 30 to diminish in size as they travel from the
container 32 toward the opening 40.
[0057] Furthermore, the combustion of the particles of the
pyrotechnic material 30 in the housing 12 causes the heat generated
by such combustion to be transferred directly and thermally to the
molecules of the gas in the housing 12 without substantial contact
with the housing 12, the end plug 18 and the manifold 36. The
housing 12, the container 32, the end plug 18 and the manifold 36
present low thermal conductivity surfaces to interface with the
heated gas, thereby causing the heat liberated from the combustion
of the pyrotechnic material to be utilized effectively only to heat
and expand such gas.
[0058] As previously indicated, the gas in the housing 12 is
preferably nitrogen, helium or argon. All limit chemical reaction
between the pyrotechnic material 30, or any by-products or end
products resulting from the combustion of such pyrotechnic
material, and such gas. Of the inert gases, argon is preferred
because it has a low thermal conductivity. As a result, a
substantial portion of the heat generated by the combustion of the
particles of the pyrotechnic material 30 is trapped within the
molecules of the argon gas. This heat is used to raise the
temperature of the molecules of the argon gas in the housing 12. It
expands the argon gas in the housing and increases the pressure of
the argon gas against the diaphragm 38.
[0059] The frangible container 32 and the housing 12 also
co-operate in maximizing the temperature increase of the gas in the
housing 12 as a result of the heat generated by the particulate
combustion. The housing 12 and the container 32 are made from low
thermal conductivity materials, at least on the surfaces in contact
with the gas. Such materials may be ceramics, rubber coatings,
polyethylene coatings and the like. These materials have relatively
low thermal conductivities as compared to relatively high thermal
conductivity of materials such as steel or aluminum that may be
used for the structure of housing 12 and the container 32.
[0060] The housing 12 and the container 32 also do not absorb any
significant amount of the generated heat because they are exposed
to high temperatures only for relatively short periods of time of
approximately ten milliseconds (10 ms) or less. This is in contrast
to most previously known inflators that function at such elevated
temperatures for approximately thirty to sixty milliseconds (30-60
ms). During such relatively extended periods of time, significant
heat is transferred to the members forming such inflators.
[0061] When the gas has expanded sufficiently in the housing 12,
the diaphragm 38 breaks and the gas expands through the opening 40
and the conduit 42. The conduit 42 may be optional. By eliminating
the conduit 42, the heated gas is transferred directly through the
opening 40 to the inflatable belt portion 104. The area of the
diaphragm 38 and the cross section areas of the opening 40 and the
conduit 42 may be selected to control the time for the rupture of
the diaphragm 38 and the flow of the gas through the opening and
the conduit into the inflatable belt portion 104. The particular
composition of the pyrotechnic material 30 and the relative sizes
of the different particles in such material also control the time
within which the gas is to be heated within the container 32, and
accordingly controls the time for the gas to flow into the
inflatable belt portion 104.
[0062] The gas flowing through the conduit 42 passes into an
inflatable member such as the inflatable shoulder belt portion 104
which may be made from a suitable material such as nylon or
polyester and may be included in a unitary belt generally indicated
at 100 (FIGS. 3 and 4). The unitary belt 100 is adapted to be
disposed in a vehicle generally indicated at 102. The unitary belt
100 is constructed to protect an occupant in the event of a
collision involving the vehicle 102. As illustrated in FIGS. 3 and
4, the inflatable belt portion 104 of the unitary belt 100 is
attached at its upper end to a support structure such as a pillar
106 which is disposed at the side of the vehicle 102 and above a
seat 108 which holds the occupant. The pillar 106 is disposed to
the rear of a vehicle door 10 through which the front seat occupant
enters and exits. The support structure may alternately constitute
any other suitable portion of the vehicle. For example, the support
structure may constitute a flange on the inner surface of the roof
portion when the inflatable belt portion 104 protects an occupant
in the rear seat of the vehicle. As illustrated in FIG. 21, the
support structure may constitute a structural seat affixed to a
structural floor or frame of the vehicle.
[0063] There are numerous ways to provide and position the
inflator. The inflator 10 shown in FIG. 4 is preferably disposed at
the upper end of the inflatable belt portion 104. When the
inflatable belt portion 104 is attached to the pillar 106, this
attachment may be at the upper end of the pillar 106. The
inflatable belt portion 104 may be preferably integrated between a
decorative fascia with the standard shoulder belt adjustment
mechanism enabling the upper position of the inflatable belt
portion to fit most favorably the full range of occupants. The
inflatable belt portion 104 is preferably disposed above the
occupant's shoulder and above the occupant's neck and approximately
at a horizontal level approximating the occupant's cheek (left
cheek if the occupant is the driver).
[0064] Alternatively, the inflator may be installed into the
webbing and clamped into position away from the largest inflated
diameter section of the inflatable belt portion. An embodiment of
this configuration is illustrated in FIG. 21. As a further
alternative, the inflator may be positioned externally to the
inflatable portion of the belt and a port provided in the belt that
is operably connected to the inflator as shown in FIG. 4. The port
may be at the end of the inflatable belt portion or along the
length thereof.
[0065] The inflatable belt portion 104 may be folded in a manner as
shown in FIG. 6. As shown in FIG. 6, the inflatable belt portion
104 is provided with a pair of opposed wall portions 104a and 104b
laterally displaced from each other. Each of the wall portions 104a
and 104b extends in a zigzag configuration from the lateral
extremity of such wall portion to a position intermediate the
lateral distance between the lateral extremities of such wall
portions. This relationship enhances the speed at which the
inflatable belt portion 104 in the embodiment shown in FIGS. 3, 4
and 8 can be inflated downwardly from the top of the inflatable
belt portion across the chest of the occupant. It also enhances the
uniformity in the inflation downwardly of the inflatable belt
portion 104. In like manner, the inflatable lap belt portion 160
shown in FIG. 21 is preferably folded to enhance the speed and
uniformity of the inflation away from the gas generator and across
the lap of the occupant.
[0066] A cover 105 (FIG. 9) preferably envelops the inflatable belt
portion 104. The cover 105 may be formed from a suitable material
such as polyester and may be provided with a color matching the
decor of the interior of the vehicle 102. The cover 105 may be
formed from a single piece of material attached at its opposite
ends as by stitching 109 The stitching 109 may be disposed to face
the body of the occupant so that it is not visible to other
occupants in the vehicle. The cover 105 becomes separated
progressively from the inflatable belt portion 104 as the
inflatable belt portion becomes inflated. Preferably a stiffener
107 is disposed within the cover 105 against the inflatable belt
portion 104 to prevent the inflatable belt portion 104 from
twisting so that the inflatable belt portion is in a flattened
configuration prior to inflation.
[0067] The cover 105 provides several advantages. It prevents the
inflatable belt portion 104 from becoming degraded as from
ultraviolet light. It also prevents the inflatable belt portion 104
from becoming degraded as from chafing against the chest of the
occupant. It additionally holds the inflatable belt portion 104 to
a consistent initial minimal volume and holds the folds of the
inflatable belt portion to provide a consistent unfolding of the
belt portion during its inflation. It also reduces the stress on
the inflatable belt portion 104 as it becomes inflated. The
stiffener 107 also assists in retaining the folds of the inflatable
belt portion 104 to provide a consistent unfolding of the belt
portion.
[0068] The inflatable shoulder belt portion 104 extends diagonally
(at a transverse angle) downwardly to a position near, but above,
the occupant's lap at the inner or inboard side of the occupant's
seat 108. In this diagonal or transverse configuration, the
inflatable belt portion 104 crosses the occupant's chest. As shown
in the embodiment illustrated in FIGS. 5 and 7, at the lower
position, the bottom of the lower end of the inflatable belt
portion 104 is suitably connected to a standard seat belt webbing
material that forms a lap belt portion 112. This may be
accomplished by stitching with a reinforcing stitch known as a
boxed-X pattern stitch (FIGS. 5 and 7), although other stitches can
be used, for example, a curved nine-point diamond pattern stitch
(FIG. 14). The lap belt portion 112 may be made from a suitable
material such as nylon or polyester. The construction of the lap
belt portion 112 may correspond to the construction of the lap
belts now in use. The inflatable shoulder belt portion 104 and the
lap belt portion 112 may be considered to form a unitary belt.
Alternatively, in the embodiment shown in FIG. 8, the inflatable
shoulder belt portion 104 and the lap belt portion 112 are
integrally formed as by weaving a textile structure as shown in
FIGS. 19, 20 or 22. As shown in FIG. 19, the integrally woven lap
belt portion is hollow and inflatable. As shown in FIGS. 20 and 22,
the integrally woven lap belt portion is flat and not hollow and
inflatable. Alternatively, the inflatable belt portion may be
attached by appropriate stitching to a continuation of a tubular
textile cover material.
[0069] At a position near, but above, the occupant's lap, the lap
belt portion 112 extends through a D-ring coupling member 116 (FIG.
8). A D-ring coupling member such as the D-ring coupling member 116
is well known in the art. The D-ring coupling member 116 has an
opening 115 (FIG. 5) through which the lap belt portion 112 extends
to change the direction of the lap belt portion 112 from a downward
and transverse direction to substantially a horizontal direction
(FIG. 8) in which the lap belt portion extends across the
occupant's lap. At its inboard end, the lap belt portion 112 is
attached to the D-ring coupling member 116 (FIG. 3) that is
removably coupled to a retainer 122 in the vehicle. The
construction of the D-ring coupling member 116 and the retainer 122
is well known in the art for use in vehicles such as automobiles
now on the market.
[0070] In the embodiment shown in FIG. 21, the 2-point lap belt is
affixed to a coupling member 116 capable of being detachably
attached to retainer 122. The construction of the D-ring coupling
member 116 and the retainer 122 is well known in the art for use in
vehicles such as automobiles now on the market.
[0071] The inflatable shoulder belt portion 104 becomes inflated
downwardly from the top of the belt when the inflator 10 is
actuated. This is advantageous because it is desirable to exclude
the mounting of the inflator 10 in undesirable locations such as
the buckle and retractor locations due to their attendant gas and
electrical connection deficiencies. Furthermore, the inflation of
the inflatable shoulder belt portion 104 downwardly from the top of
the inflatable belt portion facilitates protection initially of the
head, neck and chest of the occupant. This is advantageous because
an injury to the occupant's head, neck and chest can be life ending
but an injury to the occupant's lower extremities such as the
occupant's knees and ankles is generally at worst crippling.
Furthermore, the case of a side impact of the vehicle 102, the time
available for interspacing the protective cushion between the head
and the interior of the side of the vehicle in a collision against
the side of the vehicle is relatively short (e.g. 10-15
milliseconds). The downward inflation of the inflatable shoulder
belt portion 104 from the top of the inflatable belt portion is
particularly beneficial in such situations.
[0072] As will be seen from FIG. 4, the inflatable shoulder belt
portion 104, when inflated, protects the occupant's neck and head.
This controls the occupant's head motion by providing an inflated
cushion that supports the occupant's head from beneath the chin and
prevents the occupant's head from rotating violently in a forward
direction. When the occupant's head rotates violently forward, as
in the prior art, accompanied by a forward movement of the
occupant's chest, the occupant's head may impinge against the
dashboard or instrument panel or steering wheel (when the occupant
is in a front seat) unless adequate restraint against this movement
is provided as in this invention. Furthermore, the occupant's neck
may be severely strained, as in the prior art, as a result of the
violent jerk imparted downwardly to the neck at the time of the
collision. It will be appreciated that the inflatable shoulder belt
portion of this invention also protects the occupant's chest and
legs. When the occupant is sitting in the rear seat, the occupant's
neck and head are protected in this manner by the inflatable belt
portion of this invention from moving against the rear of the front
seat.
[0073] When the inflatable shoulder belt portion 104 becomes
inflated, its effective length is shortened as the path length of
the inflated material in the inflatable belt portion is forced
outwardly. This in turn draws the webbing portion of the lap belt
portion 112 through the D-ring portion of the coupling member 116
when the coupling member is coupled to the retainer 122. This
causes the lap belt portion 112 to become tightened against the lap
of the occupant. The lap belt portion 112, when tightened by the
inflation of the inflatable belt portion 104, restricts the
movements of the occupant's lower torso. This inhibits the
occupant's lower body from sliding forwardly and accordingly
significantly mitigates the chance that the occupant's knees and
feet will be injured. It also positions occupant's upper torso so
that the occupant's head and chest can be most effectively
restrained. In like manner, when the inflatable lap belt portion
160 (FIG. 21) becomes inflated, its length is shortened.
[0074] The amount of the pyrotechnic material 30 in the container
32 is so small and the inflation of the inflatable belt portion 104
is so fast that the temperature of the inflatable belt portion
increases only a minimal amount. For example, the temperature rise
of the inflatable belt portion 104, 160 as a result of the
inflation of such belt portion may be approximately only 7 degrees
Fahrenheit. This prevents the occupant from being burned such as
sometimes occurs in the inflatable restraints of the prior art.
[0075] As shown in FIGS. 5 and 6, the inflatable belt portion 104
is relatively narrow before inflation. This results from the zigzag
folded configuration of each of the wall portions 104a and 104b
from the lateral extremity of such wall portion to a position
intermediate the wall portions. This is shown in FIGS. 5 and 6.
However, when the inflatable belt portion 104 becomes inflated, it
expands so that the lateral distance between the wall portions 104a
and 104b becomes considerably increased. This is best seen in FIGS.
7 and 8. This is advantageous since the unit force imposed upon the
occupant's body at any position on the chest, neck and head of the
occupant's body is considerably reduced by the significant increase
in the area of contact of the inflatable belt portion 104 against
the occupant's body. The inflatable lap belt portion 160 (FIG. 21)
is likewise preferably folded before inflation.
[0076] The lap belt portion 112 is adapted to be coupled to a
retractor 124 fixedly disposed in the vehicle near the floor of the
vehicle. Alternatively, the retractor 124 may be affixed to the
floor of the vehicle or the seat. The retractor 124 may be
constructed in a conventional manner well known in the art to
dispose (e.g. wind) the lap belt portion 112 on the retractor to
allow the unwinding of the lap belt portion from the retractor.
Suitable retractors are used with lap belts in vehicles now on the
market. For example, the retractor 124 may constitute a Webbing
Velocity Sensitive Retractor (Part No. 501580-4031) available from
Am-Safe, Inc. of Phoenix, Ariz., USA. This retractor is
incorporated by reference in this application.
[0077] The retractor 124 prevents the lap belt portion 12 from
being extended upon the occurrence of a collision involving the
vehicle 102. Since the lap belt portion 112 cannot be extended at
such a time, the inflation of the inflatable shoulder belt portion
104 produces a tightening of the lap belt portion 12 against the
lap of the occupant. At the same time, the inflatable shoulder belt
portion 104 becomes disposed adjacent to the occupant's head, neck
and chest to substantially restrain movement of these portions of
the occupant's body.
[0078] When the coupling member 116 (FIGS. 3, 5 and 8) is detached
from the retainer 122 in a manner well known in the art, the
retractor 124 causes the lap belt portion 104 to become disposed
(e.g., wound) on the retractor. As a result, the inflatable belt
portion 104 becomes disposed downwardly to a position adjacent, but
to the rear of, the seat 108. This is shown in broken lines in FIG.
8. In the instance where the upper end of the inflatable belt
portion 104 is attached to the pillar 106, the occupant is able to
enter and exit the vehicle through the front door without any
obstruction from any portion of the inflatable belt 104 since the
pillar is to the rear of the front door. As shown in FIG. 21, when
the coupling member 116 is detached from the retainer 122 in a
manner well known in the art, the retractor 124 mounted under the
seat 108 causes the inflatable lap belt portion 160 to be drawn
across the seat toward roller guide 103.
[0079] As will be seen, the inflatable belt assembly 100 is
advantageous because it can be fitted or retrofitted in a vehicle
without having to alter any of the components or sub-assemblies in
the vehicle. The unitary belt 100 can be provided for the occupant
of the driver's seat, the occupant of the other front seat and the
occupants in the rear seats. The unitary belt 100 is provided as an
integral assembly in each of these seats, in part because the
inflator 10 for inflating the inflatable belt portion 104 is
disposed in juxtaposition to such inflatable belt portion.
[0080] As will be appreciated from the above discussion, the
inflatable belt portion 104 becomes inflated almost instantaneously
after the occurrence of a collision involving the vehicle. As the
inflation reaches the bottom of the inflatable belt portion 104
(the end distal from the inflator), it exerts a large stress upon
the inflatable belt portion 104, which is believed to be
particularly high at the end portion that is last to be filled with
gas. While the inventors do not wish to be held to a single theory,
it is believed that this stress is caused by a pulse or shock wave
in the inflation gas due to the high velocity at which it enters
and fills the inflatable belt portion. In the construction
illustrated in FIGS. 5 and 7, this corresponds to the bottom end of
the inflatable belt portion 104. which is also the position of
thickness discontinuity between the relatively thin fabric section
of the inflatable belt portion 104 and the thicker portion of the
webbing of the standard seat belt construction as represented by
the lap belt portion 112. This webbing constitutes the material of
the lap belt portion 112. The position of the thickness
discontinuity is at the position where the inflatable belt portion
112 is attached to the lap belt portion 112.
[0081] Upon inflation, the large stress at the position of the
thickness discontinuity between the inflatable belt portion 104 and
the lap belt portion 112 may tend to tear the relatively thin
material of the inflatable belt portion 104 and separate the
inflatable belt portion 104 from the lap belt portion 112 if
measures were not provided to prevent this from occurring. If the
inflatable belt portion 104 became fully separated from the
inflatable belt portion 112, the desirable effects of inflating the
inflatable belt portion 104 would be lost from the standpoint of
protecting the occupant.
[0082] One way for resolving the problem discussed in the previous
two paragraphs is a stitching arrangement as generally indicated at
130 in FIGS. 5-7. The stitching arrangement includes pluralities
132a, 132b, 132c, 132d and 132e of stitches 134 arranged in a
saw-tooth or zigzag pattern that extends along the end of the belt
portion 104 or even into belt portion 112. As best seen in FIG. 5,
the pluralities 132a, 132c and 132e of the stitches 134 have a
greater length than the pluralities 132b and 132d of the stitches
134. The pluralities 132b and 132d of the stitches 134 are
preferably disposed respectively between the pluralities 132a and
132c of the stitches 134 and between the pluralities 132c and 132e
of the stitches 134. It will be appreciated that the pluralities of
the stitches 134 may have the same or variable lengths. When the
inflatable belt portion 104 becomes inflated downwardly from the
upper position of such belt portion, the force produced on the thin
inflatable cloth constituting the inflatable belt portion 104 at
the bottom end of such inflatable belt portion is attenuated as it
acts upon progressive ones of the stitches 134 in each of the
pluralities 132a, 132b, 132c, 132d and 132e. This action loads each
stitch progressively to the point of separation and thereby
provides for a separation of such stitch. This may be
illustratively seen in FIG. 7. However, this stitching arrangement
is not required in all embodiments of inflatable belt portions;
some embodiments exhibit sufficient inherent strength to resist
these stresses.
[0083] The large inflation-induced stress at the position of the
end of the tubular inflatable belt portion 104 where it is joined
to the lap belt portion 112 can alternatively be addressed by
provision of the lower end of the inflatable belt portion 104 with
an elastomeric reinforcement where it is joined to the webbing
forming lap belt portion 112. The folds adjacent the lower end of
the inflatable belt portion 104 are coated and adhered to one
another with an elastomeric material such as self-curing silicone.
The elastomeric material progressively tears away as inflation
proceeds, thereby reducing the load on the cloth of the inflatable
belt portion below that at which the cloth would rupture due to the
inflation gas pulse. However, this elastomeric or silicone
reinforcement is not required in all embodiments of continuous
inflatable belt portions; some embodiments exhibit sufficient
inherent strength to resist these stresses. In certain embodiments,
such an elastomeric reinforcement can be used in combination with
other means to resist this large stress.
[0084] At a position removed in the inflatable belt 104 from the
pluralities 132a, 132b, 132d, 132d and 132e of the stitches 134,
additional stitches 136 and 138 (FIGS. 6 and 7) are disposed
laterally across the widths of the overlapping inflatable belt
portion 104 and the lap belt portion 112 at spaced positions along
the overlapping lengths of the inflatable belt portion and the lap
belt portion. Additional stitches extend diagonally from each
lateral edge of the stitches 136 to the other lateral edge of the
stitches 138 to define a criss-cross pattern. Such diagonal
stitches are indicated at 140 and 142. These stitches serve to
transmit the loads carried by one lateral edge of the inflatable
belt portion 104 along the lateral dimensions of the inflatable
belt portion 104 and the lap belt portion 112 to the other lateral
edge of the inflatable belt portion. The combination of stitches
136, 138, 140 and 142 may be referred to as a boxed-X stitch.
[0085] The large stress at the lower end of the inflatable belt
portion 104 can alternatively be addressed by provision of the
lower end of the inflatable belt portion 104 as a seamless hollow
inflatable member. In certain preferred embodiments, the one-piece
tapered woven textile maintains continuity as the seamless fabric
tapers from a larger size to a smaller size. As the size of the
hollow textile becomes smaller, the warp ends per unit of width
(weft direction of the textile) increase, thereby inherently
increasing the rupture resistance at the end of the tapered tubular
textile. Also, in certain preferred embodiments, selected wefts and
optionally selected warps may be formed of filamentary material
that is only partially oriented, that is, intentionally not fully
drawn and heat set at the time of manufacture. In this latter
instance, inflation of the hollow inflatable member causes these
plastically extensible weft ends and warp ends to be further drawn
in the event that the stress due to internal inflation pressure
exceeds a threshold value, thereby dissipating the inflation gas
energy and pressure that might otherwise rupture the inflatable
belt portion 104 or its (sewn) connection to the lap belt portion
112. Selective placement of plastically extensible warp ends can be
used to assist in inflation and expansion of the inflatable belt
portion away from the body of the occupant. As such partially
oriented fibrous member is drawn, it increases in orientation and
strength. In certain applications, use of partially oriented
plastically extensible weft members permits manufacture of a
tapered tubular woven inflatable belt portion in which the large
diameter portion and the small diameter portions are of the same or
nearly the same diameter as woven and expand to different diameters
when inflated. This simplifies manufacture of the seamless hollow
textile for the inflatable belt portion and enables provision of an
inflatable belt portion that is lighter and less voluminous in its
uninflated state as compared to prior inflatable restraint
belts.
[0086] At the conclusion of the collision event, it is preferable
that the inflatable belt portion deflate at least partially to
facilitate egress from the vehicle. This may be accomplished
through diffusion of the inflation gas through the fabric of the
inflatable belt portion 104, 160 which may be designed to have a
specific porosity, or through one or more vents provided in the
inflatable belt portion 104, 160. In all cases, the inflation
system provides sufficient gas before and during the collision
event to inflate and maintain inflation of the inflatable belt
portion 104, 160 sufficient to protect the occupant and when the
inflator has exhausted preferably allows deflation in a short time
of several seconds.
Manufacture of Tapered Seamless Textile Structure for Use in
Inflatable Belt Portion
[0087] Suitable seamless hollow textiles for use in inflatable belt
portion 104, 160 made be made as follows. Suitable seamless tapered
textiles 60, 70 such as are shown in FIG. 10 and FIG. 11
respectively having a cavity 61, 71 of changing size or diameter
may be manufactured by weaving a tubular shape as a pair of
two-dimensional, layered surfaces that are joined at their edges as
shown in FIG. 12. A tube 78 is woven so as to produce two textile
layers 80, 81 lying over each other in which only the edge regions
82, 84 are woven together. For this, the shuttle-weaving technology
is especially advantageous, because the weft 85 is therefore uncut,
alternatingly woven about warps 87 into the upper textile layer 80
and the lower textile layer 81 and consequently no seam locations
form within the range of the woven tubular textile. Also, automatic
needle weaving machines like those manufactured by Jakob Muller of
Frick, Switzerland may be used, though the weft member must be held
at the selvedge of the textile, which results in a more or less
distinct bulge in the warp direction of the textile.
[0088] Previously known processes for the weaving of tubular
structures generate a constant textile width. The diameter of the
woven cavity, and thus the woven tube, is therefore constant. In
certain embodiments of the invention having an inflatable belt
portion, however, a hollow textile is preferred where a more or
less strongly tapering diameter or where a constant conicity
between two different diameters is desired. Tapered cavity textile
structures could be produced until now only by a spiral wrapping
(filament winding) process or by an interlacing (braiding) process.
The spiral wrapping (filament winding) process is very time
consuming and costly and is limited by the danger of movement of
the yarn members on the developing core. The interlacing (braiding)
process cannot lay yarn members in the circumferential direction of
a tube. Because the braid yarn members are not laid in the
circumferential direction, their full strength is not available to
the resist hoop (circumferential direction) stress which exists
when the textile structure is inflated. The cavity size can not be
changed in a continuous braiding process, except by passing a
mandrel of the desired pattern through the braiding machine, with
the attendant difficulty of subsequently removing the mandrel.
[0089] The goal of finding a woven textile structure that forms a
cavity, e.g. a tubular structure, where the fibrous members proceed
in axial and in circumferential directions, and where the cavity
diameter itself increases or reduces in the direction of the warp
members may be achieved as described herein below.
[0090] In one embodiment for changing the cavity diameter, as shown
in FIG. 10, the spacing of the warps 62 from one another is
contracted as well as spread apart during manufacture of the
textile 60. The overall number of the warps thus remains constant
in the textile 60. The textile width changes as the spacing of the
warps 62 changes and thus does the diameter of the woven cavity
61.
[0091] In another embodiment for changing of the warp width and
thus the cavity width of the textile, as shown in FIG. 11, warps 72
are removed or added as weaving of the textile 70 proceeds.
Individual or groups of warps are periodically left behind to
remain in the high or low compartment position of the weaving
apparatus while the cavity 71 is being woven. These warps 72 float
for a distance outside of the surface of the woven structure as
shown in FIG. 11. At such sites, where these warps 72 are tied in
again into the textile, the textile width increases and thus the
woven cavity 71 or tube diameter likewise increases. For this
manufacturing process, it is advantageous to use a jacquard machine
with single warp member control It is also advantageous to use for
the support of the changing textile width a fan-like weaving reed
90 as shown in FIG. 13 together with a mechanism which catches and
positions the selvedges of the fabric, or other different equipment
that gives the warps the desired lateral spacing.
[0092] Conventional shuttle weaving technology is especially
advantageous for the production of the seamless tubular members
having variable warp widths. According to conventional weaving
technology, the bobbin of weft material and shuttle are together
conveyed through the weaving surface as shown in FIG. 12 and,
because the weft member 85 is not severed at the selvedge but is
returned and carried back in the following layer, selvedges 82, 84
are formed. The weft member 85 is returned alternatingly in the
upper textile layer 80 and the lower textile layer 81. The prepared
textile 78 has thus a cavity 86 and tubular structure without a
seam location since the upper layer 80 turns at the selvedges 82,
84 without interruption of the lower layer 81 turns. Combination of
this type of fabric production with one of the proposed warp
lateral spacing or width variations provides a seamless woven tube
with different diameters.
[0093] As an alternative or auxiliary method of manufacture, the
width or size of the textile cavity 61, 71, 86 respectively shown
in FIGS. 10, 11, 12 may be reduced by increasing the weft member
tension which leads to a constriction of the warp members and thus
to a changed textile width. It is advantageous in this instance to
have an adjustable weft-yarn brake that at certain times brakes the
weft yarn more and at other times less.
[0094] In another embodiment of a seamless tubular textile
structure, more than two layers can be woven over each other, e.g.
three as shown in FIGS. 15 and 16. These embodiments therefore
result in two more superposed cavities (181, 182 of textile 180 in
FIG. 15 and 191, 192 of textile 190 in FIG. 16) or chambers that
proceed in the warp direction. The proposed width-changing
techniques described herein also therefore lead to the narrowing or
widening of the cavities of the seamless multiple cavity tubular
textile 180, 190. For use in the inflatable belt portion 104, 160
one or more of the cavities could be connected to the source of
inflation gas. As shown in FIG. 16, at least a portion of one of
the cavities could be formed from warp members of greater strength
than the warp members of the other one of the cavities to provide
greater structural capacity. As shown in FIG. 16, portion 193 of
the bottom of the bottom cavity 191 is formed of warps 194 that are
of greater size and strength than the remainder of the warps
forming seamless hollow inflatable textile 190. In use in the
inflatable seat belt of this invention, the warp members of greater
strength are positioned against the body (chest or lap) of the
occupant, thereby reducing the stress on the thinner material of
the inflatable cavity of the inflatable belt portion at the
position of the thickness discontinuity between the inflatable belt
portion 104 and the lap belt portion 112. As shown in FIG. 16, the
inflatable belt portion includes warp members 194 of greater
strength and greater resistance to elongation under an imposed
tensile load that are positioned to correspond to the area of the
inflatable belt portion which contacts the body (chest or lap) of
the occupant, thereby preventing undesired elongation of the
unitary belt in a collision in the event that inflation does not
occur or the inflatable portion becomes ruptured.
[0095] In certain preferred embodiments, such as those shown in
FIGS. 15 and 16, the system is configured to cause the lower
chamber 181, 191 of the inflatable belt portion to inflate first,
and thereafter the inflation gas passes (as indicated by the
arrows) from the lower chamber 181, 191 through ports 185 (FIG. 15)
or porous section 195 (FIG. 16) in the middle textile layer into
the upper chamber 182, 192 to subsequently inflate the upper
chamber. In use the lower chamber 181 191 is positioned adjacent
the body of the occupant. Sequential inflation beginning with the
lower chamber followed by inflation of the upper chamber serves to
more gradually impose a force on the occupant, thereby assisting
the occupant to be positioned correctly relative to the seat and
the seat belt system as the second chamber is subsequently inflated
to more fully protect the occupant. Use of multiple chambers with
sequential inflation allows use of a greater overall chamber size
without as great a risk of rupture of the inflatable belt portion
or injury of the occupant due to sudden expansion of the inflatable
belt portion. This is particularly of value where the inflatable
belt portion 160 extends across the lap of the occupant, as in an
arrangement like that shown in FIG. 21. In use, the chamber 191
positioned in contact with the occupant is first inflated and the
remaining chamber 192 or chambers are subsequently inflated,
thereby assisting to position the occupant in a preferred upright
posture in the event of a collision when the occupant is not
sitting upright.
[0096] In another embodiment of a seamless tubular textile
structure, a vertically adjustable fan-shaped weaving reed or guide
90 like that shown in FIG. 13, or such as is described in WO
96/31643 to Busgen, is employed to assist the narrowing or
spreading of the warp yarns. The fan-shaped reed pieces are moved
together as a unit so that a vertical shift in weaving reed
position causes a narrowing or spreading of the lateral spacing of
the warp members. In practice, the fan-shaped reed 90 is positioned
dependent on the particular weft in the predetermined textile
pattern thereby causing the warp members to become more or less
densely packed. A programmed computer or microprocessor may be
employed to control the position of the fan-shaped reed. The less
densely packed warp members result in a wider textile width, and
thus larger cavity size or diameter, and the more densely packed
warp members result in a narrower textile width and thus smaller
cavity size or diameter.
[0097] Elements of a suitable weaving apparatus 240 are shown
schematically in FIG. 23. The warp yarns 241 are drawn from warp
beam 242 over letoff guide roll 243 through the eyes of heddles 244
and fan-shaped weaving reed 245 by takeup roll 250. In practice in
the manufacture of a single cavity hollow textile, there are four
groups of warp yarns, two for the upper layer of the hollow textile
and two for the lower layer of the hollow textile, although only
two are observable. The spacing of the warp yarns 241 in the shed
is controlled by the position of fan-shaped reed 245 which as shown
may be moved upward or downward or toward or away or combinations
of these movements relative to the heddles to vary the spacing of
the warp yarns 241 as the shuttle 246 containing a bobbin 247 of
weft yarn 248 is passed through the shed. The weaving apparatus 240
is equipped with selvedge guides 249 which grip the selvedges of
the newly formed hollow textile 251 and guide it to the takeup roll
250. The position of the selvedge roller guides 249 is varied in
correspondence to the warp spacing as determined by the position of
the fan-shaped reed 245. For simplicity of illustration, the
harnesses for vertical movement of the heddles are not shown, as
these are well known to those of ordinary skill in the textile
art.
[0098] In another embodiment of a seamless tubular textile
structure, a weaving guide having laterally movable warp guide
members (not illustrated) is employed. Alternatively, an actively
working adjustment can be used that laterally directs and positions
the warp members.
[0099] For use in inflatable belt assemblies, seamless hollow or
tubular textile structures can be produced as a continuous member
of changing cavity size, the pattern being periodically repeated as
shown in FIGS. 19, 20 and 22 as desired for the required inflatable
belt portion 112, 160, and subsequently severed in the smaller
cavity portions to provide a plurality of like inflatable members.
Alternatively, individual seamless hollow or tubular textile
structures of changing cavity size can be produced one at a time,
the weaving pattern being repeated after severance of the preceding
completed structure.
[0100] In certain embodiments, as shown in FIGS. 20 and 22, the
seamless hollow textile structure 200 and 220 respectively is
manufactured with plastically extensible filaments 202 (partially
oriented yarn) in a predetermined portion of the warp members and
weft members. Where such plastically extensible filaments are
employed, any excessive stress that would otherwise arise during
inflation may be absorbed by drawing of such plastically extensible
filaments to produce a larger inflated shape 224 as shown in dashed
lines in FIG. 22 in the event that the internal gas pressure
exceeds a predetermined threshold value that otherwise might cause
tearing of the fabric of the inflatable belt portion. Type N13
nylon available from DuPont having an elongation of 300 or more
percent is an example of a plastically extensible filamentary
material that can be used. Yarns of different degrees of plastic
extensibility may be employed in the manufacture of the hollow
textile structure for use in a restraint system of the invention.
Unstabilized yarns may be used at weaving in selected or all
locations to allow shrinkage in subsequent treatment operations to
tighten the weave. In contrast, the remainder of the hollow textile
structure is formed of higher tensile yield point yarns that have a
much lower elongation capability, e.g. about 20 percent.
[0101] As shown in FIG. 19, the seamless hollow textile structure
200, includes first hollow end portion 201 and second hollow end
portion 203 that are joined by integral weaving to center portion
204. The number of warps 205 is constant throughout the length of
textile structure 200, but the number of wefts 206 per unit of
length is greater adjacent end portion 203 than adjacent end
portion 201. The wefts in portion 208 are more closely spaced than
the wefts in the remainder of the hollow textile structure 200.
[0102] As shown in FIG. 20, the seamless hollow textile structure
210, includes first hollow end portion 211 and second hollow end
portion 213 that are joined by integral weaving to center portion
214. The number of warps 205 is varied throughout the length of
textile structure 210, with additional warps 216 being provided in
proportion to the increase in size (circumference) of the hollow
textile structure. The number of wefts 206 per unit of length is
greater adjacent second end portion 213 than adjacent first end
portion 211. The cross-sectional configuration of second end
portion 213 changes from a hollow woven to a flat woven
construction that is not inflatable as the distance from the center
portion 214 increases.
[0103] As shown in FIG. 22, the seamless hollow textile structure
220, includes first hollow end portion 221 and second hollow end
portion 223 that are joined by integral weaving to center portion
225. The number of warps 205 is varied throughout the length of
textile structure 220, with additional warps 216 being provided in
proportion to the increase in size (circumference) of the hollow
textile structure. The number of wefts 206 per unit of length is
greater adjacent second end portion 223 than adjacent first end
portion 221. The cross-sectional configuration of second end
portion 223 changes from a hollow woven to a flat woven
construction 229 that is not inflatable as the distance from the
center portion 225 increases. The wefts 206 in portion 228 are more
closely spaced than the wefts in the remainder of the hollow
textile structure 220, and are formed of plastically extensible
yarn 202 that has a greater elongation at breakage than the
elongation at breakage of the wefts in the remainder of the hollow
textile structure 220.
[0104] A suitable tapered seamless tubular textile structure
suitable for use in an inflatable belt assembly according to the
invention may be of the following parameters. The length of the
textile structure for the inflatable belt portion is typically from
about 50 to about 75 inches, the width in the narrowest section at
each end when flattened is 2.25 inches which corresponds to an
inflated diameter in the end portions about 1.4 inches, and the
width in the widest section between the spaced end portions when
flattened is about 9 inches which corresponds to an inflated
diameter in the largest section of about 5.7 inches. The warps may
be formed of a 280 denier, 34 filament, Type 728 nylon available
from E. I. duPont de Nemours & Company, Wilmington, Del.
(DuPont), USA. According to DuPont, Type 728 nylon yarn with a
twist of 3 turns per inch (1t/cm) has an elongation at break of
about 21.8 percent. The weft may be formed of 420 denier, 68
filament, Type 743 nylon available from DuPont. According to
DuPont, Type 743 nylon yarn with a twist of 3 turns per inch
(1t/cm) has an elongation at break of about 19 percent. The textile
includes 1276 warp ends spaced around the circumference, although
it is believed that the number of warp ends can be increased to
about 1400 for improved performance. The textile includes weft
members up to a maximum of 71/inch (28/cm), although this number is
believed to be greater than is necessary to withstand the hoop
stress during inflation. The weave pattern is a variation of a
plain weave that is described as a 4.times.4 filling rib pattern
(so called because ribs are produced in the filling direction
during weaving). Shown in FIGS. 17 and 18 is another preferred
weaving pattern for an inflatable textile structure of the
invention. As shown in FIG. 17, the weft ends 230 are paired and as
shown in FIG. 18, the warp ends 232 are in groups of four in the
textile structure. Following weaving, the textile structure may be
scoured to remove any processing oils and sizings, and to improve
dyeing and adhesion of a coating, if provided, to improve retention
of the inflation gas.
[0105] In certain embodiments where the inherent resistance to gas
permeability of the fabric of the inflatable belt portion is
insufficient to allow the inflated belt portion to retain its
inflated configuration for a sufficient time after a collision, a
coating is applied to the fabric of the inflatable belt portion to
reduce gas permeability relative to that of an uncoated fabric. It
is believed that a coating is not required in every
application.
[0106] Alternatively, a tapered seamless tubular textile structure
suitable for use in an inflatable belt assembly according to the
invention may be formed as set forth above, except the textile
structure is formed of polyester as described hereinafter. The warp
member may be formed of 440 denier, 100 filament, Type 52 (low
elongation) polyester from DuPont. The weft member may be formed of
440 denier, 100 filament, Type 68 (high tenacity) polyester from
DuPont. The weave pattern may be a 4.times.4 filling rib pattern as
described above.
[0107] For use in an inflatable seat belt assembly, the seamless
tubular textile structure is pleated, e.g. using a "W" fold pattern
as shown in FIG. 6 in order to reduce the width to that of typical
restraint webbing. The number of pleats is dependent upon the width
of the textile structure before pleating and the desired width
after pleating. The pleating process may be assisted by insertion
of metal strips into the textile structure to facilitate folding of
the textile structure to the desired width. When the pleating is
complete, the resultant inflatable textile band is pressed with a
hot press similar to those that are used to press apparel.
[0108] The pleated textile structure is then covered with a tubular
cover that is weaker in a direction corresponding to the weft
direction of its associated inflatable (pleated) portion so that
upon inflation the cover tears away and allows the inflatable
structure to inflate to full dimension. The cover may be color
coordinated for aesthetic purposes. There are numerous ways to
accomplish controlled tearing away of the cover during inflation of
the inflatable belt portion 104, 160. The cover can be sewn from a
strip of fabric that is joined at its ends as by stitching 109 to
encapsulate the inflatable belt portion as shown in FIG. 9.
Suitable fabric for a sewn cover 105 is available from Precision
Fabrics Group, Greensboro, North Carolina, as style number 54516.
Alternatively, the cover can be woven as a tubular member that is
slipped over the pleated inflatable belt portion. A suitable woven
tubular cover is available from Breed of Knoxville, Tennessee. The
woven tubular cover may be designed and manufactured to be
frangible, for example, through use of weaker yarns at selected
locations or by inducing weakness by mechanical action or by a
laser. Upon inflation of the inflatable belt portion 104, the cover
cleaves along the predetermined weakness thereby allowing the
inflatable to progressively inflate to its full dimension.
[0109] The inflatable belt portion 104 may be protected against the
influx of the inflation gas, particularly if the gas is hot enough
to degrade the fabric of inflatable belt portion 104, with a fabric
shield 150 (dashed lines in FIG. 4) that is attached to the gas
outlet of the inflator 10 and inserted into the inflatable belt
portion. The concentrically arranged fabric shield 150 and hollow
belt portion 104 may be affixed to the gas outlet of the inflator
10 as by a clamp or swaged metallic ring. The internal fabric
shield 150 may be formed of silicone-coated 630 denier nylon fabric
available from Milliken Company of Spartanburg, S.C. that is woven
into a tube of about 1.75 inch diameter by about 37 inches long
having a end 151 that is configured to be attached to the gas
inlet. The internal fabric shield 150 insulates the inflatable belt
portion from the hot inflation gas and thereby minimizes the
potential of damage to the inflatable textile structure of the
inflatable belt portion. An internal fabric shield is not required
for all embodiments of the inflatable belt portion 104. For those
embodiments of an inflatable belt portion that are inherently
sufficiently strong to resist rupture due to rapid inflation with a
heated gas, no internal fabric shield is needed. For those
embodiments of an inflatable belt portion that are not inherently
sufficiently strong to resist rupture during rapid inflation, an
internal fabric shield or other thermal insulation is needed. In
practice, for the same inflatable belt portion, this may be
dependent upon the source of inflation gas. Where the gas source
produces gas at a relatively high temperature that could degrade
the material from which the inflatable belt portion is formed, an
internal fabric shield is recommended to protect the inflatable
belt portion. Where the gas source does not produce gas at a
relatively high temperature that could degrade the material from
which the inflatable belt portion is formed, an internal fabric
shield is not needed. However, such an internal fabric shield can
be employed to locally strengthen the inflatable belt portion to
resist the shock of rapid inflation, thereby enabling use of a
lighter and weaker fabric for the main tube of the inflatable belt
portion.
[0110] Inflatable belt assemblies are costly. It is accordingly
desirable that the unitary belt 100 becomes inflated only when it
is intended to be used. To accomplish this, a switch 144 (FIG. 5)
may be disposed in the retainer 122 at a position where the
coupling member is coupled to the retainer 122. The switch 144 is
closed only when the coupling member 116 is coupled to the retainer
122. The switch 144 is connected in a circuit with the connector
pins 24 in FIG. 2. As a result, the inflator 10 is actuated to
obtain combustion of the pyrotechnic material 30 only when the
switch 144 is closed. This prevents the inflatable belt portion 104
from being inflated except when the occupant intends to obtain the
protection provided by the unitary belt 100.
[0111] The system constituting this invention has certain important
advantages in its individual sub-systems and in its assembly
relationship. For example, the inflator 10 provides an almost
instantaneous opening of the container 32 (FIGS. 1 and 2) and
inflation of the inflatable belt portion, the composition of the
pyrotechnic material 30 produces environmentally friendly gas, and
there are a minimal number of components in the inflator 10. The
inflator 10 of this invention also provides for substantially
uniform operating characteristics in the unitary belt 100 even with
considerable changes in the ambient temperature in the vicinity of
the vehicle. Where the inflatable belt portion has multiple
chambers (FIGS. 15 and 16) that are sequentially inflated, greater
protection of the occupant is possible than in the past. Where the
inflatable belt portion is provided with warps 194 of increased
strength (FIG. 16), rupture of the inflatable belt portion will not
result in loss of restraint.
[0112] The unitary belt 100 also has certain important advantages.
When the inflatable belt portion 104 becomes inflated, it protects
the occupant's chest, neck and head. It also tightens the lap belt
portion 112 against the occupant across the occupant's lap. This
provides additional protection for the occupant's lower
extremities. When the occupant desires to enter or exit the
occupant door 110, the coupling member 116 is detached from the
retainer 122 and the lap belt portion 112 becomes disposed (e.g.
wound) on the retractor 124. This disposes the inflatable belt
portion 104 substantially along the seat 108 at a position to the
rear of the door 110 as shown in FIG. 8.
[0113] The system constituting this invention also has other
advantages over the prior art. For example, the housing 12 is
disposed adjacent the opening 40 and the optional conduit 42. This
helps to minimize the time for the inflatable belt portion 104 to
become inflated. It also minimizes the weight of the inflator 10
and the space occupied by the inflator. The minimization in the
weight of the inflator 10 and the space occupied by the inflator
also minimizes the amount of the pyrotechnic material 30 in the
inflator. The combustion of the pyrotechnic material 30 produces
by-products and end products that do not require a filter to be
included in the inflator.
[0114] The system of this invention is also advantageous in the
disposition of the cover 105 (FIG. 9) in enveloping relationship to
the inflatable belt portion 104 to protect the inflatable belt
portion and control the inflation of the inflatable belt portion.
The system is also advantageous in disposing the switch 144 in the
retainer 122 to provide for the operation of the system only when
the switch is closed by the disposition of the coupling member 116
in the retainer.
[0115] Although this invention has been disclosed and illustrated
with reference to particular embodiments, the principles involved
are susceptible for use in numerous other embodiments that will be
apparent to persons skilled in the art. Although the invention has
been shown and described with respect to a certain preferred
embodiment or embodiments, it is obvious that equivalent
alterations and modifications will occur to others skilled in the
art upon the reading and understanding of this specification and
the annexed drawings. In particular regard to the various functions
performed by the above described integers (components, assemblies,
devices, compositions, etc.), the terms (including a reference to a
"means") used to describe such integers are intended to correspond,
unless otherwise indicated, to any integer which performs the
specified function of the described integer (i.e., that is
functionally equivalent), even though not structurally equivalent
to the disclosed structure which performs the function in the
herein illustrated exemplary embodiment or embodiments of the
invention. In addition, while a particular feature of the invention
may have been described above with respect to only one of several
illustrated embodiments, such feature may be combined with one or
more other features of the other embodiments, as may be desired and
advantageous for any given or particular application.
[0116] In addition, the invention is considered to reside in all
workable combinations of features herein disclosed, whether
initially claimed in combination or not and whether or not
disclosed in the same embodiment. The invention is, therefore, to
be limited only as indicated by the scope of the appended
claims.
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