Piston-actuated air bag inflator with hermetic liner
First Claim
1. An inflator for delivering pure inert cold gas to an air bag comprising,a cylindrical crushable hermetic liner in which a pressurized inert gas is stored,a non-hermetic support tube for said cylindrical liner, said support tube having a first end and a second end, including a cylindrical section in which said liner is located, and having an outlet conduit positioned at said second end, said outlet conduit being sealed by a burst disk that ruptures upon a predetermined increase of pressure of the inert gas stored in said hermetic liner,a piston in sealed, slidable relation over substantially the full length of said cylindrical section of said support tube, said piston during storage of said inert gas in said hermetic liner being positioned at the end of said support tube cylindrical section that is adjacent to the first end thereof,pyrotechnic means positioned between said piston and the first end of said support tube, andmeans for activating said pyrotechnic means to move said piston through said support tube cylindrical section, crushing said hermetic liner, increasing the pressure of the stored gas in said hermetic liner and rupturing said burst disk to cause the stored gas to escape through said outlet conduit of said support tube.
2 Assignments
0 Petitions
Accused Products
Abstract
The invention is a low cost inflator having a thin-walled hermetic liner, filled with either a stored gas or a flammable fluid mixture, and having a minimal number of joints required for sealing. Structural support is provided by parts that are not required to be hermetic. To activate the inflator, a small amount of pyrotechnic is used to move a piston, crushing the thin-walled liner and compressing the stored inert gas, or alternatively compressing and igniting the stored flammable fluid mixture, causing the gas to escape into the air bag. Optionally, the stored inert gas or flammable fluid mixture can be augmented by hot gases produced by the pyrotechnic. The piston-driving material may be composed of a wide variety of pyrotechnic materials, combustible mixtures of fluid fuels and oxidants, or compatible combinations of both. The inflator design incorporating a stored combustible fluid mixture will, upon ignition of the mixture, produce a heated gas able to more quickly inflate the air bag, as compared to a cold gas or blow down system of the same size and pressure. The combustible fluid mixture is selected so that while production of undesirable incomplete products of combustion and particulate matter are minimized, the fluid mixture must be compressed to ignite, thereby eliminating storage and handling issues problematic to some inflators featuring combustible fluid mixtures.
49 Citations
29 Claims
-
1. An inflator for delivering pure inert cold gas to an air bag comprising,
a cylindrical crushable hermetic liner in which a pressurized inert gas is stored, a non-hermetic support tube for said cylindrical liner, said support tube having a first end and a second end, including a cylindrical section in which said liner is located, and having an outlet conduit positioned at said second end, said outlet conduit being sealed by a burst disk that ruptures upon a predetermined increase of pressure of the inert gas stored in said hermetic liner, a piston in sealed, slidable relation over substantially the full length of said cylindrical section of said support tube, said piston during storage of said inert gas in said hermetic liner being positioned at the end of said support tube cylindrical section that is adjacent to the first end thereof, pyrotechnic means positioned between said piston and the first end of said support tube, and means for activating said pyrotechnic means to move said piston through said support tube cylindrical section, crushing said hermetic liner, increasing the pressure of the stored gas in said hermetic liner and rupturing said burst disk to cause the stored gas to escape through said outlet conduit of said support tube.
-
10. An inflator for delivering gas to an air bag comprising,
a cylindrical crushable hermetic liner in which pressurized gas is stored, a non-hermetic support tube for said cylindrical liner, said support tube having a first end and a second end, including a cylindrical section in which said liner is located, and having an outlet conduit positioned at said second end, said outlet conduit being sealed by a burst disk that ruptures upon a predetermined pressure of the gas stored in said hermetic liner, a piston in sealed slidable relation over substantially the full length of said cylindrical section of said support tube, said piston during storage of said gas in said hermetic liner being positioned at the end of said support tube cylindrical section that is adjacent to said first end thereof, a pyrotechnic ignition source in direct contact with a premixed, combustible material positioned between said piston and the first end of said support tube, and means for activating said pyrotechnic ignition source to move said piston through said support tube cylindrical section, crushing said hermetic liner, increasing the pressure of the stored gas in said hermetic liner and rupturing said burst disk to cause the stored gas to escape through said outlet conduit of said support tube.
-
22. An inflator for delivering gas to an air bag comprising,
a first chamber, a second chamber, said first chamber being relatively small compared to said second chamber and filled with a variety of fuel and oxidant mixtures, said second chamber being defined by a crushable cylindrical hermetic liner and filled with a premixed combustible charge, a non-hermetic support tube for said hermetic liner including a cylindrical section in which said liner is located and having an outlet conduit, said outlet conduit being sealed by a burst disk that ruptures upon predetermined increase of pressure in said second chamber, a piston in sealed, slidable moving relation over substantially the full length of said cylindrical section of said support tube, and means within said first chamber to cause said piston to move and crush said crushable hermetic liner and to pressurize and cause said premixed combustible charge contained therein to ignite.
-
23. An apparatus for inflating an inflatable device, said apparatus comprising,
a first chamber including gas producing means, said first chamber including at least one gas exit opening and having sealing means normally closing said gas exit opening, the acutation of said gas producing means increasing the temperature and pressure within said first chamber, opening means to open said first chamber sealing means whereby at least a portion of said hot produced gas is expelled from said first chamber, a second chamber comprising a cylindrical crushable hermetic liner containing a supply of pressurized stored gas and a non-hermetic support tube for said hermetic liner, said support tube including a cylindrical section in which said hermetic liner is located, having a first end and a second end, and having at least one outlet orifice therein, a piston in sealed slidable relationship over substantially the full length of said support tube, said piston during storage of said gas in said hermetic liner being positioned at the end of said support tube cylindrical section that is adjacent the first end thereof, said first chamber including said gas producing means being located between said piston and the first end of said support tube, means for activating said gas producing means in said first chamber to move said piston through said support tube cylindrical section, increasing the pressure of the stored gas in said hermetic liner and crushing said hermetic liner to cause said stored gas to escape through said at least one outlet orifice in said support tube to an air bag.
-
29. An inflator for delivering gas to an air bag comprising,
a cylindrical crushable hermetic liner in which pressurized gas is stored, a non-hermetic support tube for said cylindrical liner, said support tube having a first end and a second end, including a cylindrical section in which said liner is located, and having an outlet conduit positioned at said second end, said outlet conduit being sealed by a burst disk that ruptures upon a predetermined pressure of the gas stored in said hermetic liner, a piston in sealed slidable relation over substantially the full length of said cylindrical section of said support tube, said piston during storage of said gas in said hermetic liner being positioned at the end of said support tube cylindrical section that is adjacent to said first end thereof, a pyrotechnic ignition source in direct contact with a separated fuel and oxidant mixture between said piston and the first end of said support tube, and means for activating said pyrotechnic ignition source to move said piston through said support tube cylindrical section, crushing said hermetic liner, increasing the pressure of the stored gas in said hermetic liner and rupturing said burst disk to cause the stored gas to escape through said outlet conduit of said support tube.
Specification