U.S. patent application number 12/459561 was filed with the patent office on 2009-11-05 for vehicle occupant protection system.
Invention is credited to David M. McCormick.
Application Number | 20090273168 12/459561 |
Document ID | / |
Family ID | 37452954 |
Filed Date | 2009-11-05 |
United States Patent
Application |
20090273168 |
Kind Code |
A1 |
McCormick; David M. |
November 5, 2009 |
Vehicle occupant protection system
Abstract
A vehicle occupant protection system includes a plurality of
inflatable devices, at least one fluid source for supplying a
pressurized fluid for the vehicle occupant protection system, and
at least one gas-tight manifold coupled to the at least one fluid
source for receiving pressurized fluid from the at least one fluid
source. The at least one manifold is also coupled to the plurality
of inflatable devices such that, upon activation of the vehicle
occupant protection system, the plurality of inflatable devices
receive from the at least one manifold sufficient pressurized fluid
to inflate the plurality of inflatable devices.
Inventors: |
McCormick; David M.; (St.
Clair Shores, MI) |
Correspondence
Address: |
L.C. BEGIN & ASSOCIATES, PLLC
510 HIGHLAND AVENUE, PMB 403
MILFORD
MI
48381
US
|
Family ID: |
37452954 |
Appl. No.: |
12/459561 |
Filed: |
July 2, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11442432 |
May 26, 2006 |
7591481 |
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12459561 |
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60685531 |
May 27, 2005 |
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Current U.S.
Class: |
280/736 |
Current CPC
Class: |
B60R 21/268 20130101;
B60R 21/26 20130101; B60R 2021/2765 20130101; B60R 2021/26058
20130101; B60R 2021/26094 20130101; B60R 2021/2685 20130101; B60R
21/272 20130101; B60R 2021/2615 20130101 |
Class at
Publication: |
280/736 |
International
Class: |
B60R 21/26 20060101
B60R021/26 |
Claims
1. A vehicle occupant protection system comprising: a plurality of
inflatable devices; at least one fluid source for supplying a
pressurized fluid for the vehicle occupant protection system; at
least one gas-tight manifold coupled to the at least one fluid
source for storing pressurized fluid received from the at least one
fluid source, the at least one manifold also being coupled to the
plurality of inflatable devices such that, upon activation of the
vehicle occupant protection system, the plurality of inflatable
devices receive from the at least one manifold sufficient inflation
fluid to inflate the plurality of inflatable devices; and an
inflator coupled to the at least one manifold for providing
pressurized fluid to the at least one manifold in addition to any
pressurized fluid residing in the at least one manifold.
2. The vehicle occupant protection system of claim 1 wherein the at
least one fluid source comprises at least one compressor.
4. The vehicle occupant protection system of claim 1 wherein the at
least one fluid source comprises at least one inflator.
5. The vehicle occupant protection system of claim 1 further
comprising a plurality of fluid sources for supplying pressurized
fluid for the vehicle occupant protection system, and wherein the
at least one manifold is coupled to each fluid source of the
plurality fluid sources so as to enable the at least one manifold
to receive pressurized fluid from each fluid source of the
plurality of fluid sources.
6. The vehicle occupant protection system of claim 1 further
comprising a plurality of manifolds coupled to the at least one
fluid source for storing pressurized fluid received from the at
least one fluid source, and wherein each manifold of the plurality
of manifolds is coupled to at least one respective inflatable
device of the plurality of inflatable devices, for inflating the at
least one respective inflatable device upon activation of the
vehicle occupant protection system.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of prior application Ser.
No. 11/442,432, filed on May 26, 2006, which claims the benefit of
U.S. Provisional Application No. 60/685,531, filed on May 27,
2005.
BACKGROUND OF THE INVENTION
[0002] An ongoing challenge in the design of vehicle occupant
protection systems is to simplify and compact the structure of the
system. In systems utilizing gas generators or inflators to actuate
inflatable elements of the system, one way of simplifying the
structure is to centralize the source of the inflation gases for
the various devices. However, it is also desirable to preserve the
ability to actuate various elements of the vehicle occupant
protection system individually or in various combinations, as
needed for a given collision scenario. Thus, an adequate gas supply
for each inflatable element should be ensured, while also enabling
selective inflation of the inflatable elements.
SUMMARY OF THE INVENTION
[0003] In accordance with the present invention, a vehicle occupant
protection system is provided, including a plurality of inflatable
devices, at least one fluid source for supplying a pressurized
fluid for the vehicle occupant protection system, and at least one
gas-tight manifold coupled to the at least one fluid source for
receiving pressurized fluid from the at least one fluid source. The
at least one manifold is also coupled to the plurality of
inflatable devices such that, upon activation of the vehicle
occupant protection system, the plurality of inflatable devices
receive from the at least one manifold sufficient pressurized fluid
to inflate the plurality of inflatable devices. An inflator is
coupled to the at least one manifold for providing pressurized
fluid to the at least one manifold in addition to any pressurized
fluid residing in the at least one manifold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] In the drawings illustrating embodiments of the present
invention:
[0005] FIG. 1 is a schematic view of one embodiment of a vehicle
occupant protection system in accordance with the present invention
incorporated into a vehicle;
[0006] FIG. 1A is a schematic view of the portion of the vehicle
occupant protection system shown in FIG. 2, illustrating an
alternative embodiment of the present invention;
[0007] FIG. 2 is a schematic plan view of a portion of another
embodiment of a vehicle occupant protection system in accordance
with the present invention;
[0008] FIG. 2A is a schematic side view of one chamber of the
embodiment shown in FIG. 2; and
[0009] FIG. 3 is a schematic view of a portion of yet another
embodiment of a vehicle occupant protection system in accordance
with the present invention.
DETAILED DESCRIPTION
[0010] Unless stated otherwise, the various structural constituents
described above are formed by methods known in the art. Different
metals such as carbon steel, stainless steel, aluminum, various
metallic alloys, and polymers are all contemplated as useful when
forming these parts.
[0011] Referring to FIG. 1, an inflatable vehicle occupant
protection system 10 in accordance with one embodiment of the
present invention includes at least one manifold 12, and at least
one pressurized fluid source 14 (such as a compressor or pump) in
fluid communication with manifold 12 and incorporated into a
vehicle 8. A plurality of inflatable devices 32, 34, 36, 38 (for
example, airbags or seatbelt pretensioners) is coupled to manifold
12. Upon activation of the vehicle occupant protection system,
inflation gases flow from manifold 12 to inflate one or more of the
inflatable devices. Compressor 14 is driven by, for example, the
engine 15 of vehicle 8. Compressor 14 compresses outside air drawn
through a compressor inlet 16, and discharges the gas into manifold
12 via manifold inlet 13.
[0012] In the embodiment shown in FIG. 1, manifold 12 is generally
cylindrical and of gas-tight construction. Manifold 12 includes at
least one interior chamber 12a which serves as a reservoir for
storing compressed air discharged from compressor 14. Manifold 12
has at least one inlet port for 13 receiving gas therein from
compressor 14, and at least one outlet port 18 to enable fluid
communication with a respective inflatable device coupled to the
manifold, in a manner described in greater detail below. Manifold
12 is made from one or more pieces of a metal or metal alloy and
may be a cast, drawn, extruded, or otherwise metal-formed. Separate
pieces may be joined by welding, brazing, or other suitable
means.
[0013] Manifold 12 may be positioned so as to reduce its
susceptibility to damage in the event of a vehicle collision. For
example, manifold 12 may be positioned in the engine compartment of
the vehicle, or the manifold may be enclosed within a portion of
the vehicle frame designed to withstand various predetermined
collision scenarios.
[0014] Referring to FIG. 1, in one particular embodiment, manifold
12 has a series of additional ports 18 spaced therealong to enable
fluid communication between an interior of the manifold and various
additional elements of the vehicle occupant protection system, via
distribution conduits 41. These additional elements may include,
for example, additional inflatable elements of the vehicle occupant
protection system, or gas generator modules for augmenting the
inflation gases provided by manifold 12 upon activation of the
vehicle occupant protection system. In this embodiment, manifold 12
is coupled to multiple inflatable elements of the vehicle occupant
protection system so as to provide inflation gases to any one of
(or all of) the inflatable elements upon activation of the
protection system. Thus, manifold 12 preferably has enough gas
storage capacity to provide a predetermined desired amount of
inflation gas to each of the inflatable devices coupled thereto,
under conditions defined for a particular application. Adequate
compressed fluid or gas is stored to inflate the devices so as to
enable each inflatable device to perform its intended functions.
Ports 18 not coupled to another element of the system may be
provided with a gas-tight seal (not shown) capable of resisting the
internal gas pressures within manifold 12.
[0015] An additional port (not shown) may be provided in the body
of manifold 12 for release of gases in cases where the manifold
internal pressure exceeds a predetermined range. A pressure-relief
valve (not shown) may be installed at this pressure relief port to
facilitate release of the compressed gases in the event of an
excess-pressure condition. The pressure-relief valve may actuate
automatically to release the gases when the internal pressure
exceeds the predetermined range. Alternatively, the pressure-relief
valve may be activated by any one of several known means, for
example, by a signal from a controller responsive to a signal from
a pressure sensor (not shown) positioned on the manifold so as to
enable measurement of the manifold internal pressure.
[0016] Referring again to FIG. 1, a gas supply pipe 13 conveys the
compressed gas from compressor 14 to manifold 12. A check valve 25
may be positioned along a gas flow path between compressor 14 and
manifold 12 to permit flow of pressurized gas from the compressor
to the manifold, while blocking a reverse flow of gas from the
manifold to the compressor. Any of a variety of suitable,
commercially-available check valves may be used.
[0017] Also, a discharge pipe 20 having a cut off valve 26 may be
provided for discharging the gas in manifold 12 in cases where the
engine of the motor vehicle is stopped, when the gas pressure in
manifold 12 exceeds a predetermined pressure range, or when the gas
pressure in one or more of inflatable devices 32, 34, 36, 38
exceeds a predetermined pressure range defined for the particular
inflatable device. Valve 26 may be actuated by, for example, a
signal received from a pressure sensor 24 positioned to measure the
gas pressure within manifold 12, or from a controller (such as
electronic control unit 22, described herein). Opening of valve 26
enables the gas in manifold to be vented, thereby helping to
prevent unnecessary over-stressing of the manifold structure.
Opening of valve 26 also enables venting of the gases from each
device inflated via the manifold. When the gas pressure in an
inflatable device exceeds a predetermined pressure limit defined
for that device, valve 26 (and any flow control mechanism
controlling flow from the manifold to the device) may be opened to
provide a path from the device through manifold 12 to discharge
pipe 20, thereby relieving excess pressure in the device. In
alternative embodiments, a valve or other pressure relief mechanism
for the inflatable device may be provided along a flow path between
manifold 12 and the device, or a pressure relief mechanism may be
incorporated into the structure of the inflatable device
itself.
[0018] Referring again to FIG. 1, inflatable vehicle occupant
protection devices 32, 34, 36, 38 coupled to manifold 12 may
comprise any of a variety of known or suitable inflatable elements,
such as side-curtain airbags 32, driver-side airbags 34, front and
rear seatbelt retractors 36, seatbelt pretensioners 37, and/or
passenger-side airbags 38.
[0019] Many known designs of the vehicle occupant protection system
elements set forth above have elements incorporated therein which
are actuatable using pressurized gases. For example, typical seat
belt retractor mechanisms which may be used in conjunction with the
present invention are described in U.S. Pat. Nos. 5,743,480,
5,553,803, 5,667,161, 5,451,008, 4,558,832 and 4,597,546,
incorporated herein by reference. Illustrative examples of typical
seatbelt pretensioners usable in conjunction with the present
invention are described in U.S. Pat. Nos. 6,505,790 and 6,419,177,
incorporated herein by reference.
[0020] Referring again to FIG. 1, a flow control mechanism,
generally designated 40, is provided for selectively directing
pressurized fluid from each manifold port 18 to one or more
associated inflatable vehicle occupant protection devices upon
activation of the inflation system. Many different types of flow
control mechanisms are usable in the present invention. For
example, in one embodiment, flow control mechanism 40 comprises a
seal which is rupturable, frangible, or otherwise breakable
positioned at an associated orifice in one port 18 leading from
manifold 12 to an associated inflatable device of the vehicle
occupant protection system. As used herein, the term "breakable" is
understood to mean that the seal may be rendered useless or
inoperative. The seal is positioned to block an associated gas exit
orifice leading from manifold 12, thereby forming a fluid-tight
barrier preventing flow of pressurized gas through or around the
seal. The seal is designed to prevent flow of compressed gas from
manifold 12 to the associated inflatable element when the gas
pressure within manifold 12 is within a specified range (i.e., the
pressure range in which the compressed gas is stored in manifold 12
prior to activation of the vehicle occupant protection system.) The
seal may, for example, be designed to fracture or displace due to
an overpressure condition created by ignition of an associated
igniter assembly. Alternatively, the seal may be formed from a
destructible or frangible plug positioned to close a gas flow exit
orifice and designed to break upon exposure to the heat and/or
combustions products resulting from activation of an associated
igniter assembly. One example of a flow control mechanism using
such a frangible seal is disclosed in co-owned U.S. patent
application Ser. Nos. 11/260,824, incorporated herein by reference.
Co-owned U.S. patent application Ser. Nos. 10/969,254 and
11/104,042, also incorporated herein by reference, provide
additional illustrative, non-limiting examples of flow control
mechanisms usable in the present invention. In addition, other flow
control mechanisms suitable or adaptable for the purposes described
herein are also contemplated.
[0021] Each breakable seal may be coupled to an associated igniter
assembly 70 (see FIG. 2) such that activation of the igniter
assembly produces piercing of the seal, displacement of the seal,
or deactivation of the seal by other modes, thereby enabling gas
flow from manifold 12 to an associated inflatable element of the
vehicle occupant protection system. The igniter assembly may be
activated responsive to a signal received from a sensor or
controller as described herein. Alternatively, multiple seals may
be breached by activating a single igniter assembly configured to
create a pressure surge or transient within the manifold interior
sufficient to rupture all of the seals. Thus, the seals may be
configured to be either collectively breakable, individually
breakable, or both, depending on the requirements of a projected
collision scenario.
[0022] The igniter assemblies(s) may be secured to manifold 12 or
to another portion of the vehicle using any one of several known
methods, for example, by welding, crimping, using an interference
fit, or by adhesive application. The seals may be stamped, formed,
molded or otherwise fabricated from any of a variety of gas or
fluid impermeable materials, as is known in the art. Exemplary
materials include aluminum, steel, tin and nonmetal or polymeric
seals. The materials and structure of the seal will depend on the
pressure of the fluid sealed in manifold 12 and the desired
performance characteristics of the vehicle occupant protection
system. For example, seals made from materials and/or having
structures which are relatively more or less readily ruptured may
be used.
[0023] Igniter assemblies 70 generally include an igniter and a
quantity of an ignitable material positioned so as to enable
ignition thereof upon activation of the igniter. An igniter
assembly suitable for the application described herein may be
obtained from any of a variety of known sources, for example Primex
Technologies, Inc. of Redmond, Wash. or Aerospace Propulsion
Products bv, of The Netherlands. Alternatively, an igniter assembly
suitable for use in the present invention may be constructed as
known in the art from individual components including a housing, an
igniter secured to the housing, and an ignitable material
positioned in the housing so as to enable ignition thereof upon
activation of the igniter. The igniter may be formed as known in
the art. One exemplary igniter construction is described in U.S.
Pat. No. 6,009,809, herein incorporated by reference.
[0024] The embodiments described above provide pressurized gas for
inflation of the inflatable devices, wherein the pressurized gas is
produced using non-pyrotechnic means. That is, while flow control
devices 40 may employ a squib or igniter assembly to break the seal
and release the gas in the manifold (thereby producing some exhaust
gases incident to squib activation), the primary source of
inflation gas is the pressurized gas stored in manifold 14 prior to
activation of the vehicle occupant protection system and is,
therefore, not generated using a pyrotechnic gas generant.
[0025] In certain collision scenarios, it may be necessary to
simultaneously activate most or all of the inflatable occupant
protection devices installed at various positions on the vehicle.
Manifold 12 preferably has enough capacity to store sufficient gas
at sufficient pressure to inflate all of the inflatable sub-systems
of the vehicle occupant protection system simultaneously. However,
the internal pressure and the amount of gas within manifold 12 upon
activation of the restraint system may also be adjusted by suitably
controlling the amount and/or composition of ignitable material
incorporated into one or more of the igniter assemblies used to
breach the seals. That is, the internal pressure in manifold 12 may
be increased above the normal pressure level provided by compressor
14 prior to or substantially simultaneously with transfer of the
gases to the inflatable elements, by controlling the amount and/or
composition of ignitable material in the igniter assemblies.
Increasing the amount and/or modifying the composition of ignitable
material in the igniter assemblies provides additional gas and
pressure in instances where most or all of the inflatable occupant
protection devices must be inflated simultaneously.
[0026] In another embodiment (not shown), one or more of flow
control mechanisms 40 comprise a series of valves positioned to
control a flow of gases between the manifold and the inflatable
elements of the vehicle occupant protection system. The valves
controlling flow to the inflatable devices may be collectively
actuatable (for example, responsive to a signal from a sensor or a
controller) to release all of the gas in manifold into all of the
inflatable devices substantially simultaneously. Each flow control
mechanism 40 may also or alternatively be individually actuatable
to direct pressurized gas from manifold 12 into one or more
associated elements of the vehicle occupant protection system.
[0027] Any combination of valves, rupturable seals, or other flow
control mechanisms may also be employed in a single manifold to
control flow from the manifold to individual inflatable elements of
the vehicle occupant protection system.
[0028] In yet another embodiment, a single breakable seal, valve,
or other flow control mechanism may be used to control gas flow
from the manifold to all of the associated inflatable devices. In
this embodiment, breakage of the seal or actuation of the valve
would enable pressurized gas to flow to all of the inflatable
devices substantially simultaneously, through a single outflow port
18 in manifold 12.
[0029] Also, in an embodiment where the flow control mechanism is a
valve, the valve may be used to control the inflation profile of
the inflatable device. That is, actuation of the valve may be
controlled to correspondingly control the rate of inflation,
pressure, etc. of an associated inflatable device. This may be
accomplished using, for example, a proportional control valve such
as a solenoid valve.
[0030] As is known in the art, various known collision sensors and
other types of sensors (shown schematically in FIGS. 1 and 2 as
elements 30) are distributed through the vehicle structure for
detecting an imminent collision, for reacting to an occurring
collision, or for detecting the presence of any other conditions
necessitating deployment of one or more elements of the vehicle
occupant protection system. For example, an impact sensor as
exemplified in U.S. Pat. No. 5,725,265, herein incorporated by
reference, may be employed in the vehicle occupant protection
system of the present invention. In a particular embodiment, the
sensors incorporated into the vehicle may include one or more
predictive collision sensors configured to identify a collision
condition before the actual collision occurs. For example, front,
rear, and side impact anticipatory sensors usable in the present
invention are known in the art and can use any of a variety of
technologies including optical, radar (including noise radar,
micropower impulse radar, and ultra wideband radar), acoustical,
infrared, or a combination thereof. A system employing such
predictive collision sensors may contain a neural network processor
to make a discrimination between spurious and actual crash
scenarios; however, a simulated neural network, a fuzzy logic or
other algorithm operating on a microprocessor can also be used. In
an embodiment of the vehicle occupant protection system including
anticipatory sensors, electronic control unit 22 (described in
greater detail below) is configured to operate with the
anticipatory sensors. Such sensors and the capabilities of an
electronic controller for interfacing with these sensors are
described in co-owned U.S. patent application Ser. No. 11/327,754,
incorporated herein by reference.
[0031] Referring again to FIG. 1, an electronic control unit 22
("ECU") is provided for managing actuation of flow control
mechanisms 40 responsive from inputs to sensors 30. For example, in
an embodiment where the flow control mechanism includes breakable
seals operatively coupled to associated igniter assemblies, ECU 22
is coupled to the igniter assemblies to provide actuation signals
thereto. Similarly, in an embodiment where the flow control
mechanism includes one of more valves, ECU 22 is coupled to the
valves so as to control opening and closing of the valves. ECU 22
is also coupled to the various types of sensors 30 distributed
through the vehicle for detecting an imminent collision, for
reacting to an occurring collision, or for detecting the presence
of any other conditions necessitating deployment of one or more
elements of the vehicle occupant protection system.
[0032] The general configuration of ECU 22 is known in the art. In
one embodiment, the ECU of the present invention comprises a
programmable digital computing apparatus having a processor, ROM,
RAM and I/O apparatus coupled to sensor elements 30 on the vehicle.
ECU 22 stores and runs a control program while the vehicle is in
use. The sensors 30 supply control-related data to ECU 22. The ECU
receives input signals from the vehicle sensors 30 (for example,
signals indicative of vehicle rate of acceleration, pressure
sensors for sensing the internal pressure in manifold 12, etc.) and
delivers output control signals to the actuatable flow control
mechanisms 40 of the vehicle occupant protection system responsive
to the input signals. ECU 22 also communicates with (or
incorporates) one or more crash sensor algorithms that signal
activation of one or more elements of the vehicle occupant
protection system, based on inputs from the sensors as known in the
art. ECU 22, flow control mechanisms 40 and/or any other control
elements of the vehicle occupant protection system may be
incorporated into a control system module (not shown) for coupling
to manifold 12.
[0033] Operation of the embodiment shown in FIG. 1 will now be
discussed. Referring to FIG. 1, when the vehicle engine is switched
on, compressor 14 is powered up. Air from the vehicle exterior is
drawn into the compressor and sent via conduit 13 to manifold 12.
Compressed air is fed into manifold 12 until an indication is
received by ECU 22 from pressure sensor 24 that the manifold is
charged (i.e., that the internal pressure of the manifold is within
a predetermined pressure range). In response to the pressure sensor
signal, operation of the compressor is stopped. If pressure sensor
24 senses that the internal pressure in manifold 12 has fallen
below the predetermined range during operation of the vehicle,
compressor 14 may be re-engaged to return the manifold pressure to
within the desired range.
[0034] Upon the occurrence of an imminent or current crash
condition, signals from one or more of sensors 30 are sent to ECU
22, which generates one or more control signals responsive to the
sensor input signals. The control signals are forwarded to the
appropriate actuatable flow control elements 40 controlling gas
flow to the inflatable elements selected for activation, thereby
opening the valves or disabling the seals controlling flow of the
gases out of the manifold, releasing the pressurized gases in
manifold 12 and directing the gases into the pertinent inflatable
elements of the system.
[0035] If desired, ECU 22 may direct compressor 14 to keep
operating and manifold 12 to keep channeling the pressurized gas
provided by the compressor to the selected inflatable elements
until the engine cuts out, or until some other predetermined
deactivation condition has been met. This enables a constant supply
of inflation gas to be provided to the inflatable elements during
most or all of the duration of the system activation event.
[0036] Upon the occurrence of a predetermined condition, a signal
may be forwarded to open discharge valve 26 and the valves (if any)
regulating flow between the manifold and the associated inflatable
devices, thereby permitting the compressed gases residing therein
to bleed out of the vehicle occupant protection system.
[0037] Referring to FIG. 1A, in another alternative embodiment, one
or more conventional inflators or gas generators 52 (for example,
pyrotechnic inflators) are coupled to manifold 12 to provide a
supplemental supply of inflation gas to the manifold under
conditions determined by the requirements of a particular
application. Inflator 52 may be docked to the manifold at a
connection port 18 (as described herein), or the inflator may be
positioned separate from the manifold and coupled to the manifold
using a gas-tight tube or pipe so as to enable fluid communication
between the inflator and the manifold interior upon activation of
the vehicle occupant protection system. The inflator may be
activated, for example, by a suitable signal provided by ECU 22 or
by a sensor positioned on the vehicle. The inflator may also be
activated by a signal provided by another element of the vehicle
occupant protection system or by another portion of the
vehicle.
[0038] In an embodiment incorporating a conventional inflator or
gas generator 52 for augmenting the compressed gas in manifold 12,
activation signals are conveyed to gas release mechanisms 40 and
also to supplementary gas generator 52. Activation of supplementary
gas generator 52 may be coordinated with activation of gas release
mechanisms 40 such that supplementary gas generator 52 is activated
shortly after the opening of gas release mechanisms 40, thereby
permitting the gas generated by supplementary gas generator 52 to
flow freely through manifold 12 and into the inflatable devices.
Routing the gases from the supplementary gas generator 52 through
the manifold also permits these gases to be cooled to a degree
prior to entry into the inflatable protection devices.
[0039] In yet another alternative embodiment (not shown), the
compressor or pump is omitted and the primary fluid source for the
system comprises one or more conventional inflators coupled to the
manifold. Activation of multiple inflators can be timed to provide
a flow of pressurized gas over an extended period of time. The gas
flow of these inflators is channeled through the manifold, where
flow of the gas from the manifold to the inflatable devices is
controlled using one or more of the methods previously described.
This arrangement, when used with a suitable sensor suite and an ECU
coupled thereto as described herein, enables a flow of pressurized
gas to be directed simultaneously and/or sequentially to all of the
inflatable devices coupled to the manifold, and provides a great
degree of flexibility in the number and combination of devices
inflated, and in the timing and longevity of inflation of the
devices.
[0040] Referring to FIGS. 2 and 2A, in yet another alternative
embodiment, a manifold 112 is partitioned into multiple chambers or
cavities, with each chamber storing an amount of pressurized fluid
at a pressure sufficient to inflate any or all of one or more
corresponding inflatable devices coupled to the respective chamber.
For example, in the particular embodiment shown in FIGS. 2 and 2A,
an interior of manifold 112 is divided into cavities 80a-80d by a
plurality of walls 81. Each of cavities 80a-80c is coupled (via a
corresponding segment of conduit or tubing 82a-82c) to one or more
corresponding inflatable devices 102, 104, 106 of the inflatable
vehicle occupant protection system so as to enable fluid
communication with the associated devices upon activation of the
occupant protection system. Walls 81 prevent direct fluid
communication between adjacent cavities 80a, 80b, and 80c. Each of
cavities 80a, 80b, and 80c also fluidly communicates, via an
associated orifice 84a, 84b, and 84c, with an entrance cavity 80d
which receives and stores compressed air from compressor 14 via
supply conduit 13. Check valves 90a-90c are provided along a wall
81a separating entrance cavity 80d from each of cavities 80a, 80b,
and 80c. Check valves 90a-90c permit flow of pressurized gas from
entrance chamber 80d into each of chambers 80a, 80b, and 80c, while
blocking the reverse flow of gas from chambers 80a, 80b, and 80c
into entrance chamber 80d. A plurality of breakable seals 120a-120c
is positioned to cover corresponding gas exit orifices 130a-130c
along manifold 112.
[0041] Manifold 112 of FIGS. 2 and 2A also includes a series of
bays 92a-92c formed in a wall of the manifold as previously
described, to enable coupling of an associated plurality of igniter
assemblies 101a-101c thereto. Each bay 92a-92c is in fluid
communication with an associated chamber 80a, 80b, and 80c of
manifold 12. Each igniter assembly may be attached directly to the
manifold, or may be coupled to manifold 12 (via tubing or piping)
through an associated bay which forms a gas-tight seal with the
manifold. Each igniter assembly is also attached coupled to the
manifold so as to enable fluid communication with the interior of
an associated one of chambers 80a, 80b, and 80c upon activation of
the vehicle occupant protection system.
[0042] Release of the inflation fluid in manifold cavities 80a-80c
may alternatively be controlled by valves or other actuatable flow
control elements as previously described, positioned along a flow
path between one of manifold cavities 80a-80 and a respective
inflatable device coupled thereto. These valve(s) or other flow
control elements may be actuated responsive to control signals from
sensors or from ECU 22, as previously described.
[0043] Operation of the embodiment shown in FIGS. 2 and 2A will be
described with the assumption that a breakable seal and an
associated igniter assembly is used to control flow of gases from
manifold 112. However, it will be understood that valves could be
employed in place of some or all of the breakable seals and igniter
assemblies. In operation of the embodiment shown in FIGS. 2 and 2A,
a compressor (not shown) supplies compressed air or gas through
inlet 13 to manifold entrance cavity 80d. Check valves 90a-90c
permit the compressed gas to flow from entrance cavity 80d into
each of corresponding cavities 80a, 80b, and 80c, thereby enabling
the resident gas pressure in cavities 80a, 80b, and 80c to
substantially equal the gas pressure in entrance cavity 80d. If it
is desired to selectively activate a vehicle occupant protection
sub-system (for example an inflatable device 102 associated with
chamber 80a), an activation signal is sent from the ECU to an
igniter assembly 101a associated with chamber 80a. Actuation of the
igniter assembly 101a causes a pressure surge localized within
chamber 80a, thereby piercing, displacing, or otherwise
deactivating an associated seal 120a and enabling the stored
compressed gases and the generated combustion gases to flow out of
manifold 12 through an associated gas exit orifice 130a.
[0044] The pressure surge also forces check valve 90a to close. As
gasses from chamber 80a flow out of gas exit orifice 130a, the gas
pressure within chamber 80a is reduced to a point where check valve
90a is opened by pressure of stored compressed gas in entrance
chamber 80d, thereby enabling this compressed gas to flow through
valve 90a and then through the open manifold gas exit orifice 130a
to associated inflatable device 102. As inflatable devices 104 and
106 are not to be activated, the seals 120b and 120c preventing gas
flow through gas exit orifices 130b and 130c are not disturbed, and
substantially the entire quantity of compressed gas stored in
entrance chamber 80d and in cavity 80a is available to aid in the
inflation of inflatable device 102. As stored gas flows through
check valve 90a, gas pressure within entrance chamber 80d is
reduced, thereby forcing check valves 90b and 90c to close. After
system activation, igniter assembly 101a and seal 120a blocking
flow of gas through orifice 130a can be replaced and manifold 12
re-used.
[0045] If desired, depending on the needs of a particular
application, each fluid flow path from each of cavities 80a-80c may
be provided with a separate fluid flow control device. These fluid
flow control devices may be actuatable either separately or
together. In addition, different fluid flow paths from the manifold
may be provided with different types of fluid flow control devices.
For example, fluid flow leading from cavity 80a may be controlled
by a burst disk which is pierced by an overpressure condition
caused by ignition of an igniter assembly, while fluid flow leading
from cavity 80b is controlled by a valve secured to the manifold
proximate a fluid exit orifice for cavity 80b.
[0046] Referring again to FIG. 1, an actuatable cut off valve 25
may be provided along a gas flow path 13 between the compressor 14
and the manifold 12. Cutoff valve 25 adjusts an amount of gas
supplied to manifold 12 in accordance with, for example, a control
signal from ECU 22.
[0047] Referring now to FIG. 3, in another embodiment, multiple
manifolds 12a-12b are filled with gas using a single compressor 14,
and a plurality of cutoff valves 25a-25b is provided, with one
cutoff valve positioned along each gas flow path between compressor
14 and a respective one of manifolds 12a-12b. Each cutoff valve
25a-25b controls the flow of gas between compressor 14 and a
corresponding one of manifolds 12a-12b. This arrangement enables
the flow of gas between the compressor and one of manifolds 12a-12b
to be interdicted while the flow between compressor 14 and the
other one of manifolds 12a-12b to continue. This is useful in
instances where it is desired to provide a controllable flow of gas
to selected ones of multiple inflatable devices after the initial
inflation of the devices. This arrangement also enables control of
the flow of gas between each individual manifold and one or more
inflatable devices connected to the manifold, thereby enabling one
or more of the inflatable devices to be activated while other
inflatable devices remain inactive. Cutoff valves 25a-25b may be
actuated, for example, by a control signal received from a sensor
30 or from ECU 22.
[0048] Again, if desired, depending on the needs of a particular
application, each fluid flow path from each of manifolds 12a-12b
may be provided with a separate fluid flow control device. These
fluid flow control devices may be actuatable either separately or
together. In addition, different fluid flow paths from the manifold
may be provided with different types of fluid flow control devices.
For example, fluid flow leading from manifold 12a may be controlled
by a burst disk which is pierced by an overpressure condition
caused by ignition of an igniter, while fluid flow leading from
manifold 12b is controlled by a valve secured to the manifold
proximate a fluid exit orifice for cavity 12b.
[0049] In other alternative embodiments (not shown), the gas
release mechanisms may be incorporated into (or positioned
proximate) the associated inflatable device of the vehicle occupant
protection system, rather than located centrally on or about the
manifold.
[0050] As described above, the vehicle occupant protection system
of the present invention utilizes relatively clean exterior air as
the primary inflation gas. Thus, the use of pyrotechnic material
and gas generating material for inflating the inflatable elements
of the vehicle occupant protection system can be either eliminated
or significantly reduced.
[0051] Also, elements of the vehicle occupant protection system
described herein may be incorporated into one or more modules
designed for ease of assembly and replacement.
[0052] Furthermore, it may be seen in all of the embodiments set
forth herein, that all of the gases used to inflate the inflatable
devices are channeled through the manifold. The fact that all of
the gases are channeled through the manifold and the arrangement of
actuatable flow control devices described herein, when used with a
suitable sensor suite and an ECU coupled thereto, enables a flow of
pressurized gas to be directed selectively and simultaneously
and/or sequentially to each of the inflatable devices coupled to
the manifold, and provides a great degree of flexibility in the
number and combination of devices inflated, and in the timing and
longevity of inflation of the devices, and the amount of
pressurized gas made available for inflation of the devices.
[0053] In addition, in embodiments of the present invention which
use conventional gas generators to augment gas flow, the number of
gas generators used, and the number of different types of gas
generators, may be reduced. Furthermore, mixing of gas generant
combustion products with the exterior air aids in cooling the
combustion products prior to expulsion into the inflatable device.
Also, different gas generator designs may be docked to a port of
the manifold as described herein, by the use of an adapter designed
to mate the particular gas generator design with the manifold port
configuration. Thus, many different existing gas generator designs
may be used in conjunction with the present invention.
[0054] It will be understood that the foregoing descriptions of
embodiments of the present invention are for illustrative purposes
only. As such, the various structural and operational features
herein disclosed are susceptible to a number of modifications
commensurate with the abilities of one of ordinary skill in the
art, none of which departs from the scope of the present invention
as defined in the appended claims.
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