United States Patent
`
`1191
`
`[111
`
`4,021,058
`
`Suzuki et al.
`[45]
`May 3, 1977
`
`
`[54] SAFETY BAG DEVICE FOR VEHICLE
`
`3,847,412
`
`1 1/1974 Mattson ........................... .. 280/736
`
`[75]
`
`Inventors: Mikio Suzuki, Hekinan; Yoshiyuki
`Hanoi-i, Nagoya, both of Japan
`[73] Assignee: Nippon Soken, Inc., Nishio, Japan
`[22] Filed:
`Oct. 28, 1975
`.
`[21] APPL N0-3 6269565
`[30]
`Foreign Application priority Data
`Oct. 30, 1974
`Japan ......................... 49-125740
`[52] U.S. Cl. ................................. .. 280/737; 222/3;
`137/68 A; 137/516.11; 137/71
`Int. Cl.” ....................................... .. B60R 21/08
`[51]
`[58] Field of Search ........ .. 280/735, 736, 741, 742,
`280/737; 137/68 A, 71, 516.11, 543.15;
`222/3
`
`*
`
`[56]
`-'
`
`3,093,155
`3,777,772
`3,797,853
`3,813,007
`
`References Cited
`
`UNITED STATES PATENTS
`6/1963
`Dawes ...................... 137/516.11 x
`l2/1973 Arnold et al.
`................... .. 280/737
`
`3/1974 Grosch et a1.
`... . . . .
`.. .. . . . .. 137/71
`5/ I974
`Doin et al.
`.....................
`280/736
`
`Bet“
`Pfimafl’ E«Wmi"e"*K_e““eth
`éttogney, Agent, or Fzrm—-Cushman, Darby &
`51178 man
`ABSTRACT
`,
`_
`[
`1
`_
`In a safety bag device for use in a vehicle and of the
`type wherein a rupture plate is interposed between a
`high pressure gas container and a conduit leadingto an
`inflatable safety bag. A nozzle having a plurality of
`nozzle holes opened into the conduit is interposed be_
`tween the rupture plate and the conduit. A spool is
`slidably fitted to the nozzle in such a way that it may
`normally close a pyedetermmed number of nozzle
`holes, but may be displaced away from the nozzle to
`open them in response to the increase in pressure in the
`nozzle chamber when the rupture plate is ruptured in
`case of a collision, whereby the flow rate of the high
`pressure gas flowing into the inflatable safety bag may
`be suitably controlled so _as to prevent very rapid ex-
`P““‘:‘°“ °f the bag resulmg "‘ the “‘3“’3' t° 3" °°°"'
`Pa“ -
`_
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`4 Claims, 5 Drawing Figures
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`U.S. Patent May 3, 1977
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`Sheet 1 of3
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`4,021,058
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`U.S. Patent May 3, 1977
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`Sheet 2 of 3
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`FIG 2
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`U.S. Patent May 3, 1977
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`Sheet 3 of3
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`4,021,058
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`FIG. 4
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`P/PESZSU/?E/NC'0N774/NE/?
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`SAFETY BAG DEVICE FOR VEHICLE
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates to generally a safety
`bag device for protecting the occupants in a vehicle in
`case of a collision, and more particularly to a safety bag
`device provided with a flow control device for control-
`ling the flow rate of the. high pressure gas to be injected
`into an inflatable safety bag..
`I
`There hasbeen devised and demonstrated a safety
`bag device of the type comprising an inflatable safety
`bag, a high pressure gas container‘, a conduit adapted to
`lead the high pressure gas discharge out of the con-
`tainer» into the safety bag, a rupture plate interposed
`between the container and the conduit, a cylindrical
`spool guide disposed within the container, the opened
`end of said spool guide. being fitted into the outlet
`opening of the container and closed with the rupture
`plate, said spool guide having a plurality of holes
`formed through the side wall thereof for admitting
`therein the high pressure gas in the container, and a
`spool slidably fitted into the spool guide in such a way
`as to open and close the holes, thereby controlling the
`flow rate of the high pressure gas flowing into the safety
`bag when the rupture plate is ruptured in case of a
`collision of the vehicle. In the safety bag device of the
`type described, an electric detonator is placed adjacent
`the rupture plate so that in case of a collision, the deto-
`nator is ignited to explode to rupture the rupture plate.
`< As a result, the high pressure gas in the container flows
`through the holes of the guide into the conduit and then
`into the safety bag. However, the safety bag device of
`the type described has some defects that when the
`space between the guide and the spool slidably fitted
`therein is too small, the fragments of the ruptured plate
`impinge against the spool and that the impact of the
`explosion is exerted to the spool. As a result, the
`smooth displacement of the spool is adversely affected
`so that the satisfactory flow control of the high pressure
`gas cannot be attained. -Further, when the space is
`increased in order to overcome the above problem, the
`flow rate of the high pressure gas increases resulting in
`I very rapid expansion ofthe safety bag, thus causing the
`injury to the occupant.
`A
`SUMMARY OF THE INVENTION
`
`One of the objects of the present invention is there-
`fore to provide. a safety bag devicewherein the flow
`rate of the high pressure gas charged into the safety bag
`in case of a collision maybe suitably controlled,
`whereby the injury to the occupant by the sudden ex-
`pansion ofthe safety bag may be positively prevented.
`. The above and other objects maybe attained by a
`safety bag device in accordance with the ‘present inven-
`tion comprising an inflatable safety bag, a high pressure
`. gas source, a conduit adapted to lead the gas dis-
`charged from the; gas source into the safety bag, rup-
`,. ture plate means interposed between the gas source
`. and the conduit for normally interrupting the commu-
`nication therebetween except for the case of a collision
`of the vehicle, a nozzle interposed between the rupture
`plate means and the conduit and having a plurality of
`nozzle holes opened into the conduit, and spool means
`slidably fitted to the nozzle for closing a predetermined
`number of the nozzle holes when the rupture plate is
`not ruptured and for opening the nozzle holes in re-
`sponse to the pressure increase in the nozzle as a result
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`of the rupture of said rupture means, whereby the flow
`rate of the high pressure gas flowing into the safety bag
`may be suitably controlled so as to prevent the sudden
`expansion of the safety bag.
`The. above and other objects, features and advan-
`tages of the present invention will become more appar-
`ent from the following description of one preferred
`embodiment thereof take in conjunction with the ac-
`companying drawing.
`'
`
`BRIEF DESCRIPTION OF THE DRAWING
`
`FIG. 1 is a schematic view, partly in section, of a
`safety bag device in accordance with the present inven-
`tion;
`. FIG. 2 is a fragmentary sectionalview thereof illus-
`trating a spool in nonnal position immediately after the
`rupture of a rupture plate;
`FIG. 3 is a view similar to FIG. 2, but illustrates the
`spool in retracted position; and
`FIGS. 4 and 5 are diagrams used for the explanation
`of the mode of operation of the device in accordance
`with, the present invention.
`Same reference numerals are used to designate simi-
`lar parts throughout the figure.
`‘
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`Referring first to FIG. 1 illustrating one preferred
`embodiment of the present invention, a high pressure
`container constituting a high pressure gas source 1 has
`its outlet opening closed with a rupture plate assembly
`2 including an electric detonator 3 electrically con-
`nected to collision detecting devices and a power sup-
`ply (both not shown) through lead wires. The rupture
`plate assembly 2 has externally threaded ‘screws and
`screwed into the internally screw threaded opening of
`the high pressure container 1, and the electronic deto-
`nator 3 is adapted to be ignited inresponse to the out-
`put signals from the collision detecting devices, thereby
`causing the rupture on the rupture plate assembly 2 so
`as to permit the discharge of the high pressure gas from
`the high pressure gas container ,1 into an inflatable
`safety bag B through a nozzle 4 and a conduit 12 as will
`be described in detail hereinafter. The portion 2’ to be
`ruptured", namely rupture plate, of the rupture plate
`assembly 2 is formed thinner or defined by an annular
`groove so that the ruptured opening with a predeter-
`mined opening area may be provided. In the instant
`embodiment, the high pressure gas container 1 con-
`tains the high pressure nitrogen. However, it is to be
`understood that it may contain any suitable high pres-
`sure gas with or without a gas-forming agent.
`The nozzle 4 is interposed between the rupture plate
`assembly 2 and the conduit 12, and has a plurality of
`small- and large diameter nozzle holes 13 and 14
`opened into the conduit 12. The small-and-large diam-
`eter nozzle holes 13 and 14 are arrayed in circumferen-
`tial rows, respectively, and the row of the small diame-
`ter nozzle holes 13 is located closer to the rupture plate
`assembly 2 than the row of the large diameter nozzle
`holes 14.
`L
`‘
`Within a guide 6 in the form of a cylinder attached to
`the conduit 12 at a right angle relative to the axis
`thereof is slidably fitted. a spool 5 which is slidable
`between the inner wall of the guide 6 and the outer wall
`surface of the nozzle 4, and is biased by a bias spring 7
`so as to normally close the large diameter holes 14.
`Therefore, immediately after the rupture of the portion
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`2' of the rupture plate assembly 2, the flow rate of the
`high pressure gas discharged out of the high pressure
`gas container 1 and flowing into the inflatable bag B is
`controlled by the small diameter nozzle holes 13. A seal
`ring 8 is interposed between the nozzle 4 and the spool
`5. The space 17 within the nozzle 4 is communicated
`with the space 11 defined between the nozzle 4 and the
`spool 5 through a plurality of small diameter holes 9
`axially formed through the cylindrical side wall of the
`noule 4 so that the high pressure gas may be intro-
`duced into the space 11. The space 15 defined by the
`spool 5 and the guide 6, is communicated, not with the
`conduit 12, but with the surrounding atmosphere
`through a hole 10 formed through the wall of the guide
`6 so that the pressure in the space 15 equals the atmo-
`spheric pressure.
`The outlet of the conduit 12 is joined by welding to a
`diffuser D with a plurality of slits S through which is
`charged the high pressure gas into the bag B. Within
`the diffuser D are disposed a tubular perforated plate P
`and a filter F consisting of a few layers of wire screens
`wound in the form of a tube in order to prevent the
`passage into the bag B of the smaller fragments pro-
`duced by the ignition and explosion of the electric
`detonator 3 and the rupture of the portion 2’ of the
`rupture plate assembly and a retainer R which is made
`of, for instance, rubber, and is supporting the electric
`delonator 3.
`
`In the instant embodiment, the inflatable bag B is
`made of plain weave nylon cloth sheet and of the con-
`ventional type provided with suction holes (not shown)
`for introducing the surrounding air, and is nonnally
`folded as shown in FIG. 1.
`
`Next the mode of operation of the air safety bag
`device with the above construction will be described
`with reference to FIGS. 2 and 3. In case of a collision,
`in response to the output signals from the collision
`detecting devices (not shown), the electric detonator 3
`is ignited and exploded to rupture the portion 2’ of the
`rupture plate assembly 2 so that the rupture opening 16
`is formed. As a result, the high pressure nitrogen gas is
`discharged out of the container 1 into the nozzle 4, and
`larger explosion and rupture fragments are received in
`the space 17 in the nozzle 4. The discharged high pres-
`sure nitrogen gas flows into the conduit 12 as indicated
`by the arrows through the small diameter nozzle holes
`13. Concurrently, the high pressure nitrogen gas flows
`through the holes 9 into the space 11, thereby forcing
`the spool 5 to_retract away from the large diameter
`nozzle holes 14 against the bias spring 7 so that the
`large diameter holes 14 are gradually opened. As a
`result, the flow rate of the high pressure nitrogen gas
`flowing into the conduit 12 through the nozzle 4 is
`gradually increased. Until the large diameter nozzle
`holes 14 are wide open, the expansion of the bag B is so
`slow that the injuries to the occupant due to the sudden
`expansion of the bag B are completely prevented.
`When the large diameter nozzle holes 14 are wide open
`as shown in FIG. 3, the flow rate of the high pressure
`nitrogen gas is increased so that the bag B is inflated
`fully within a short time to protect the occupant.
`Next referring to FIG. 4, the relationship between the
`area S of the ruptured opening 16 (See FIGS. 2 and 3)
`and the total area S’ of the small-and-large diameter
`nozzle holes 13 and 14, on the one hand, and the pres-
`sure variation in the nitrogen gas in the container 1 will
`be described. When the flow control device consisting
`of the nozzle 4, the spool 5, and bias spring 7 is not
`
`provided, the pressure change is very rapid as indicated
`by the curve a in FIG. 4. However, when the flow con-
`trol device is provided in such way that S > S’ or S .5.
`S’, the pressure change is slow as indicated by the curve
`c or b. Thus, the injuries to the occupants by the sudden
`expansion of the safety bag B may be very effectively
`prevented by the provision of the flow control device in
`accordance with the presentinvention.
`Furthermore, as shown in FIG. 4, when the ratio S/S’
`is suitably selected, the pressure change in the con-
`tainer 1 may be suitably controlled after the time t,
`when the large-diameter nozzle holes ' 14 are wide
`opened. .
`When the ratio S/S’ is so selected as to obtain the
`pressure change curve b and when the total opening
`area S” of the holes’9 is changed, the pressure curves
`as shown in FIG. 5 are obtained. That is, the curve b’
`represents when the total opening area S" is smaller
`while the curve b”, when the total opening area S" is
`larger. It is seen that when the total opening’ area S” is
`larger, both the time t,” when the large diameter noz-
`zle holes 14 are started to be opened and the time t,"
`when the large diameter nozzle holes 14 are wide
`opened are faster than the corresponding time t," and
`the time t2’ when the total opening area S" is smaller.
`Thus, the desired expansion or inflation characteristics
`of the safety bags may be attained by suitably selecting
`the ratio among the opening areas S, S’ and S" and the
`pressure of the bias spring 7.
`So far the nozzle holes 13 and 14 of the nozzle 4 have
`been described as having the different diameters or
`opening areas, but it is to be understood that they may
`have the same diameter or opening area if the pitches
`of the nozzle hole rows are different, that is, the num-
`ber of nozzle holes 14 is larger than thatxof nozzle holes
`13.
`-
`
`As described above, in a safety bag device for use in
`a vehicle and of the type in which a. -rupture plate is
`interposed between a high pressure gas container and a
`conduit communicating the container with the bag,
`according to the present invention, a nozzle having a
`plurality of circumferential
`rows of nozzle holes
`opened into the conduit is interposed between the rup-
`ture plate and the conduit, and a spool is slidably fitted
`to the nozzle in such a way that a predetermined num-
`ber of nozzle holes of the nozzle may be closed and
`opened in response to the pressure in the nozzle,
`whereby the flow rate of the high pressure gas flowing
`into the safety bag may be controlled. Therefore the
`rapid and dangerous expansion of the safety bag after
`the rupture of the rupture plate may be positively pre-
`vented, and the desired safety bag expansion or infla-
`tion characteristics may be attained. Furthermore, the
`flow rate control of the high pressure gas is not ad-
`versely affected by the larger fragments produced by
`the explosion and rupture.
`I
`What is claimed is:
`
`1. In a safety bag device for use in a vehicle and of the
`type comprising an-inflatable safety bag, a high pres-
`sure gas source, a conduit for leading the gas dis-
`charged from said gas source into said bag, and rupture
`plate means interposed between said gas source and
`said conduit for normally interrupting the communica-
`tion between said gas source and said conduit unless
`said rupture plate means is ruptured in case of a colli-
`sion of the vehicle, the improvement comprising:
`a nozzle member interposed between said rupture
`plate means and said conduit and having a nozzle
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`guide means attached to said conduit for guiding
`sliding movement of said spool means; and
`a bias spring disposed between said spool means and
`said guide means for urging said spool in a direc-
`tion opposite to said first direction, whereby the
`flow rate of the high pressure gas into said safety
`bag may be controlled to be low at the intitial stage
`and higher thereafter.
`2. An improvement as set forth in claim 1, wherein
`said plurality of said nozzle holes are arrayed in a plu-
`rality of rows.
`3. An improvement as set forth in claim 1, wherein
`said rows comprises a first row and a second row, the
`first row includes a plurality of small diameter nozzle
`holes while the second row, a plurality of large diame-
`_ter holes.
`4. An improvement as set forth in claim 1, wherein a
`space is formed in said nozzle at one end portion
`thereof in opposed relation with the inlet port thereof,
`whereby the fragments produced by the rupture of said
`rupture plate means may be carried by the high pres-
`sure gas flow and received in said space.
`fl!
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`chamber and a plurality of nozzle holes opening
`into said conduit from said nozzle chamber for
`conducting gas from said source to said conduit
`following rupture of said rupture plate means, said
`nozzle member also having a head portion and at
`least one communication hole formed in said head
`portion and opening into said nozzle chamber;
`spool means fitted to said nozzle member so as to
`define outside the head portion of said nozzle
`member a spool chamber communicating with said
`nozzle chamber through said communication hole,
`said spool means closing a predetermined number
`of said nozzle holes when said rupture plate is not
`ruptured and being slidable with respect to said
`nozzle member and in a first direction to open the
`predetermined number of nozzle holes when pres-
`sure in said spool chamber reaches a predeter-
`mined value as gas is introduced through said com-
`munication hole into said chamber in response to
`an increase in pressure in said nozzle chamber as a
`result of the rupture of said rupture plate means;
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