Inflator for automobile safety device

• US 4,131,300 A
• Filed: 12/30/1974
• Issued: 12/26/1978
• Est. Priority Date: 07/05/1973
• Status: Expired due to Term

• Current Assignee: Allied Chemical Corporation (Honeywell International Inc.)
• Original Assignee: Allied Chemical Corporation (Honeywell International Inc.)
• Inventors: Lewis, Donald J., Radke, Donald G.
• Primary Examiner(s): Reeves, Robert B.
• Assistant Examiner(s): Skaggs, H. Grant
• Application Number:
  US05/537,497
• Time in Patent Office: 1,457 Days
• Field of Search: 280/150 AB, 280/734, 280/736, 280/737, 280/740, 280/741, 222/3
• US Class Current: 280/737
• CPC Class Codes: B60R 21/2035 using modules containing inflator, bag and cover attachable to the steering wheel as a complete sub-unit steering wheel covers with tear lines B60R21/21656; assembling of modules B60R21/217
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

A method and apparatus compact enough for use in locations, such as in the steering wheel column of a vehicle for inflating a safety device, such as a bag. A stored compressed gas from a stored gas chamber is mixed in a mixing chamber with a combustion gas from a gas generating chamber. A combustion gas barrier between the gas generating chamber and the mixing chamber is designed to rupture when the heat and pressure in the gas generating chamber exceeds a maximum temperature and pressure, allowing combustion gas from a combustible material in the gas generating chamber to flow into the mixing chamber. A hybrid gas barrier between the mixing chamber and an outlet means is designed to rupture when the heat and pressure in the mixing chamber exceeds the maximum temperature and pressure, allowing the gas mixture to flow from the mixing chamber through an outlet means to inflate the safety bag. A strainer disposed between the gas generating chamber and the combustion gas barrier prevents the passage of most of the combustion residue resulting from combustion of the combustible material from the gas generating chamber to the mixing chamber. The gas generating chamber is separate from and outside of the stored gas container, as a result of which the transfer of heat from the combustible material and the combustion gas to the stored gas chamber is minimized.

Claims

1. A method for inflating at least one safety bag, said method comprising the steps of:

(a) filling a stored gas zone with a compressed gas, said stored gas zone being in communication with a mixing zone;

(b) firing a combustible material disposed in a gas generating zone, said gas generating zone being separate from said stored gas zone, upon impact of said vehicle whereby a combustion gas is generated in said gas generating zone;

(c) releasing said generated combustion gas to said mixing zone;

(d) mixing said combustion gas with said compressed stored gas in said mixing zone, thereby forming a hybrid gas in said mixing zone composed of said generated combustion gas and said stored compressed gas; and

(e) releasing said hybrid gas directly to an outlet in communication with said safety bag; and

wherein;

(f) the step of releasing said generated combustion gas and the step of releasing said hybrid gas are accomplished substantially simultaneously; and

(g) the step of releasing the combustion gas comprises rupturing a combustion gas barrier at weak points in said barrier, thereby producing small ports in said barrier and increasing the velocity of the combustion gas passing through said ports.

2. An apparatus for inflating at least one safety device, said apparatus comprising:

(a) a stored gas chamber adapted to be filled with a compressed gas;

(b) a gas generating chamber, adjacent to but separate from said stored gas chamber, said gas generating chamber being adapted to contain a combustible material, said combustible material being adapted to generate high pressure combustion gas in said gas generating chamber upon combustion, said gas generating chamber being adapted to contain an actuating means for igniting said combustible material, thereby causing combustion of said combustible material;

(c) a mixing chamber in communication with said stored gas chamber, in which mixing chamber said stored compressed gas and said generated combustion gas are mixed to form a hybrid gas adapted for inflating said safety device;

(d) a combustion gas barrier disposed between said mixing chamber and said gas generating chamber, said combustion gas barrier being adapted to prevent said stored compressed gas from entering said gas generating chamber from said mixing chamber prior to actuation of said combustible material, and being designed to rupture when the heat and pressure in said gas generating chamber exceed a predetermined temperature and pressure of said combustion gas barrier, whereby said combustion gas flows into said mixing chamber;

(e) an outlet means being disposed between and being adjacent to said mixing chamber and said safety device, through which outlet means said hybrid gas passes from said mixing chamber to said safety device; and

(f) a hybrid gas barrier disposed between said mixing chamber and said outlet means to prevent said stored compressed gas from entering said outlet means from said mixing chamber prior to actuation of said combustible material, said hybrid gas barrier being adapted to rupture when the heat and pressure in said mixing chamber exceed a predetermined temperature and pressure, whereby said hybrid gas flows through said outlet means and into said safety device; and

wherein;

(g) said combustion gas barrier has weak points disposed therein, said weak points being designed to rupture when the heat and pressure in said gas generating chamber exceed a predetermined temperature and pressure; and

(h) said combustion gas barrier ruptures only at said weak points and thereby produces small ports in said barrier, thereby increasing the velocity of said combustion gas passing through said ports.

3. A unitary and compact apparatus for inflating at least one safety device, said apparatus comprising:

(a) a stored gas chamber adapted to be filled with a compressed gas, said stored gas chamber disposed around at least part of the outer periphery of said apparatus, said stored gas chamber having walls defining said stored gas chamber, said stored gas chamber adapted to be disposed adjacent to said safety device;

(b) a gas generating chamber disposed in said apparatus adjacent to, inside of, partially contiguous with, but separate from said stored gas chamber and adapted to be disposed in close proximity to said safety bag, said gas generating chamber having walls defining said gas generating chamber, at least one of said walls of said gas generating chamber disposed at least partially contiguous with at least one wall of said stored gas chamber;

(c) a combustible material disposed in said gas generating chamber, said combustible material being adapted to generate a high pressure combustion gas upon combustion;

(d) an actuating means disposed at least partially in said gas generating chamber and adapted to ignite said combustible material;

(e) a mixing chamber disposed in said apparatus, said mixing chamber having walls defining said mixing chamber, at least one of said walls of said mixing chamber disposed at least partially contiguously with said stored gas chamber, said stored gas chamber at least partially surrounding said mixing chamber, said mixing chamber having a passageway through said at least partially contiguous wall between said mixing chamber and said stored gas chamber, the length of said passageway being approximately equal to the total thickness of said wall in the area of said wall where said passageway is located, said mixing chamber thereby being in direct communication with said stored gas chamber, said mixing chamber adapted to be disposed in close proximity to said safety device, said stored compressed gas and said generated combustion gas being mixed in said mixing chamber to form a hybrid gas adapted for inflating said safety device;

(f) a combustion gas barrier disposed between said mixing chamber and said gas generating chamber, said combustion gas barrier being adapted to prevent said stored compressed gas from entering said gas generating chamber from said mixing chamber prior to ignition of said combustible material, said combustion gas barrier having weak points disposed therein, said weak points being designed to rupture to produce gas jet emitting ports in said barrier when the heat and pressure in said gas generating chamber exceed a predetermined temperature and pressure, whereby said combustion gas flows into said mixing chamber;

(g) an outlet means being disposed between and being adjacent to said mixing chamber and said safety device, through which outlet means said hybrid gas passes from said mixing chamber to said safety device; and

(h) a hybrid gas barrier disposed between said mixing chamber and said outlet means to prevent said stored compressed gas from entering said outlet means from said mixing chamber prior to actuation of said combustible material, said hybrid gas barrier being adapted to rupture as a result of the heat and pressure in said mixing chamber exceeding a predetermined temperature and pressure, whereby said hybrid gas flows through said outlet means and into said safety device.