Air Bag Explosive Device

This invention relates to a separable seal for a container opening having a throat with a restriction therein as well as the method for opening the sealed aperture.

In the past, various devices have been developed for explosively opening containers for the purpose of releasing compressed gas in the containers. Rapid release of the gas is necessary where the application of a pressurized container is employed in a safety device such as an air bag for automobiles. The expansion time must be in milliseconds. In order to achieve a sudden release of large volumes of compressed gas, a large opening must be blown to effect substantially instantaneous release of high pressure gas. Noddin U.S. Pat. No. 3,780,752 shows a typical explosive actuated valve sealed by a frangible diaphragm. Moyant U.S. Pat. No. 3,670,925 is also a similar explosive frangible type device. Such typical valves can be used in high pressure systems of 5,000 psi or more and can release gas in less than 2 milliseconds. Typical of various attempts to achieve a stable and reliable system are Maxon U.S. Pat. Nos. 3,313,113 and Hopson 3,191,533. Mechanical devices have also been tried, including a plunger system such as disclosed in McDaniel U.S. Pat. No. 3,887,108.

In the Noddin and Moyant patents, stability of the system is made to rely on tempered glass.

Chute U.S. Pat. No. 3,638,964 proposes a system using an explosive system which can reduce noise but nevertheless is complex and difficult to manufacture and maintain for long periods of time.

It is an object of this development to provide a means for rapidly opening a pressurized gas container to release a large volume of the gas in a very short period of time.

Another object of this invention is to provide a system which can be maintained under very adverse conditions of temperature and pressure such as for example 4,500 to 5,000 psi and 130.degree. F.

Yet another object of this invention is to provide a cheap and inexpensive device which can be mass produced with standard equipment without the necessity of having complex apparatus and equipment or the need to obtain complex materials for manufacturing the device.

Still another object of this invention is to provide a blowout seal for high pressure cartridges which can be manufactured from a chosen steel, thereby eliminating the need for expensive materials.

Still another object of this invention is to provide a device which can be inserted in standard vessels and welded for structural strength therein with a minimum of difficulty and with standard equipment.

A further object of this invention is to provide a method of blowing out a large sealed area in order to obtain substantially instantaneous release of very high pressure gases in order to effect rapid inflation of a bag for safety purposes in automobiles and the like.

Yet a further object of this invention is to provide a seal projectile insertable in a pressure vessel which incorporates therewith a plastic case for the explosive charge and which when fired ejects both case and projectile simultaneously to clear the opening in the pressure vessel.

A further object of this invention is to provide a diffusion cap which can be secured to the seal for catching the projectile and case and diffusing the gases without the likelihood of any injury to a person who might be in close proximity to the device when it is fired.

In summary, this invention is designed to provide an explosive insert for a high pressure vessel which will automatically release gases quickly and safely.

These and other objects of this invention will be apparent from a study of the drawings in which the following figures are noted:

FIG. 1 is a top plan view of the rapid pressure release closure or insert.

FIG. 2 is a cross-sectional view taken along the lines 2--2 of FIG. 1 and viewed in the direction of the arrows.

FIG. 3 is a cross-sectional view of the plastic case without the explosive and showing the firing wires.

FIG. 4 is a cross-sectional view of the insert including the projectile with its peripheral diaphragm and the plastic casing removed.

FIG. 5 is a cross-sectional view showing a modification of the insert including a diffusion cap secured to the top of the insert.

FIG. 6 is a cross-sectional view of a modification of the invention in which the insert is provided with a central opening to permit the vessel to which the insert is secured to be filled with pressurized gas.

FIG. 7 is a fragmentary cross-sectional view of a pressurized vessel with the insert of FIG. 6 in place and showing a nut holding down a casing in the insert.

FIG. 8 is a modification of the invention showing a separable diaphragm including a threaded washer plate for securing the diaphragm in position and including an annular stake above the diaphragm for securing the unit in position within the external sleeve.

FIG. 9 is a cross-sectional view of the external sleeve of the insert.

FIG. 10 is a cross-sectional view of a modified form of the projectile which would be used in the sleeve of FIG. 9.

FIG. 11 is a cross-sectional view of a modification of the invention shown in FIG. 12 showing multiple firing mechanism and casing securing means taken along the lines of 11--11 in FIG. 12.

FIG. 12 is a top plan view of the modification of FIG. 11.

FIG. 13 is a cross-sectional view of the insert with the casing removed.

FIG. 14 is a bottom plan view of the casing with the insert removed.

FIG. 15 is a cross-sectional view taken along the lines 15--15 of FIG. 14 and viewed in the direction of the arrows.

FIG. 16 is fragmentary perspective view, a portion of which is in cross-section showing a modification of this invention using multiple retaining means for the casing.

FIG. 17 is a cross-sectional perspective view of the casing used in FIG. 16.

FIG. 18 is a cross-sectional view of a toroidal-type container with an insert having a diffuser cap in cross-section mounted thereon.

In FIGS. 1 through 4, the insert T, with the exception of the propellant casing C as best shown in FIG. 3, is made in the case of high pressure vessels of stainless steel. The casing C may be made of plastic such as nylon or the like.

The insert T includes a sleeve 2 having a flange 4 which may be welded or otherwise secured to the opening of a pressure vessel. The sleeve 2 is provided with an internal shoulder or annular groove 6. The internal surface 8 of the sleeve 2 has a narrower diameter than the internal shoulder 6 to form a restricted opening. The casing C is provided with a flange 10 which seats in the internal shoulder 6. The insert T includes a projectile 12 of stainless steel having a base or lower portion 14 thicker than a peripheral diaphragm 16 which is integral with the sleeve 2.

A stepped shank or stud 18 is provided with a threaded opening 20 for receiving a machine screw 22 which holds down the casing C. The casing C is provided with wire leads 24 and 26 connecting a bridge wire 28. The bridge wire is in contact with the primer 30 for the main charge 32 as best shown in FIG. 2. An opening 34 in the casing C is provided for positioning the casing C onto the stepped shank 18. As best seen in FIG. 2, the primer 30 and the main charge 32 are received in an annular groove 36 which is formed by concentric walls 38 and 40.

It should be noted that the charge 32 is directly over the diaphragm 16 so that when the insert T is fired, the pressure of the gases from the primer 30 and main charge 34 will force the diaphragm 16 downwardly to shear or rupture it from the wall or internal surface 8 of the sleeve 2. The downward travel will be limited by the shoulder 6 in which the flange 10 of the casing is trapped. Once the downward forces are overcome by the upward forces of the gases, the projectile 12, including the casing C, will move upwardly and out of the opening formed by the shearing of the diaphragm 16 from the wall of the sleeve 2.

An alternate form of the development is shown in FIG. 4 in the dotted lines. In this configuration, an annular ring 42 is provided beneath the base 14 of the projectile 12. The annular ring 42 prevents the projectile 12 from going any further downwardly and thus permits the charges to build up sufficiently to cause the projectile 12 and casing C to be removed entirely from the opening formed due to the shearing of the diaphragm 16 from the sleeve 2. It will be obvious in this modification, that the flange 10 and the internal shoulder 6 may be eliminated because of the annular ring 42 restricting the downward travel of the projectile 12 subsequent to the shearing of the diaphragm 16 from the wall 8 of the sleeve 2.

In FIG. 5, the flange 4 is provided with an upwardly extending sleeve 44 having threads 46 cooperating with threads 48 of a diffuser cap 50 which will catch the casing C and projectile 12 when they emerge from the opening of the sleeve 2. Ports 52 are provided for venting the gases rapidly as they are released from the vessel to which the insert T is attached.

In FIGS. 6 and 7, the insert T is shown secured to a pressurized container 54 by welding or other means at the flange 4. The projectile 12 is modified to include a stepped shank 56 provided with threading 58 and a central opening 60. A nut 62 is threaded onto the stepped shank 56. The nut 62 serves the same purpose as the machine screw 22 for holding down the casing C as in FIG. 2. The hole or opening 60 is provided for pressurizing the container 54 and is designed to be sealed off once pressurization is effected. This sealing off is done by standard means such as a plug or the like (not shown).

In FIGS. 8, 9 and 10, modifications are provided in which a sleeve 64 is manufactured which is not integral with the projectile 12. The sleeve 64 has a recessed shoulder 66. The projectile 68 includes a threaded washer 70 for supporting the diaphragm plate 72. The diaphragm plate 72 has an opening 74 for receiving the upper shank 76 of the washer 70. A staking ring 77 holds down diaphragm 72. The stepped shank 78 includes a threaded stud 80 for engaging the threads of the opening 82 of the washer 70. A nut 84 secures the casing C to the stepped shank 78.

FIG. 10 shows the projectile 68 with a filling opening 86. In this modification, the upper shank 76 has external threads for engaging the stepped shank 78.

In FIGS. 11 through 15, the insert T includes a projectile 88 having a plurality of shanks 90 secured by a plurality of screws 92 for holding down the casing C which is rectangular. Other various configurations might also be utilized.

It will be noted also that a plurality of firing mechanisms 94 are provided.

In FIGS. 16 and 17, a larger opening is contemplated and the plate 96 is provided with a weakened separation groove 98. The casing C best shown in FIG. 17 includes a plurality of holes 100 for receiving bolts 102 to which are secured nuts (not shown) for holding the casing C to the general mechanism.

In FIG. 18, the insert T includes a diffusion cap 104. The insert T is mounted in a toroidal container 106. The toroidal container is designed to be mounted on a steering column and releases gas to an inflatable envelope or bag 108. Obviously, any means can be employed to secure the container 106 to the bag 108 and thus to the steering column (not shown).

The operation of the devices described in FIGS. 5 through 18 is similar to the operation in FIGS. 1 through 4 as heretofore described.

While this invention has been described as having a preferred design, it will be understood that it is capable of further modification. This application is, therefore, intended to cover any variations, uses, or adaptations of the invention following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains, and as may be applied to the essential features hereinbefore set forth and fall within the scope of this invention or the limits of the claims.