Patent Application
20090114109
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1. Field of the Invention
The present invention relates to an igniter body for an airbag inflator and, more particularly, to a stamped igniter body having a connector portion formed of plastic that is molded or otherwise connected to the stamped igniter body.
2. Description of the Background Art
One of the major challenges in hybrid airbag inflator construction is the reduction or elimination of potential gas leaks through the materials selected for the inflator and its components. There are a number of materials and processes that have been developed to reduce the gas leakage risk. Unfortunately, owing to the precise requirements for connection to the OEM control module, the igniter housing in many inflator constructions has been machined and thus is subject to gas leakage.
In attempts to reduce parts and process costs, some inflator constructions have been developed to combine the initiator, igniter body and connector features via the use of a separate igniter/initiator assembly which is then crimped into a separate housing that is attached to the inflator body. The necessity for the separate housing adds to the cost and complexity of the inflator construction.
The new and improved stamped and molded igniter body of the present invention is not subject to the above-described disadvantages.
The igniter body of the present invention comprises a stamped body portion formed of a suitable metal and a plastic connector portion integrally molded or otherwise connected to the body portion. The stamped body portion creates a material grain flow or grain structure modification to reduce or eliminate gas leaks therethrough when used in a hybrid airbag inflator construction. The stamped body portion does not require any secondary processing such as machining or milling, and may be provided with raised areas or other retention features for retaining the plastic connector portion in place when it is integrally molded thereto. In a modified embodiment, the plastic connector portion may be separately molded and connected to the stamped body portion by a snap-fit connection or other suitable connection. The plastic connector portion may be provided with shaped orientation features for insuring the proper connection of a plug or power module thereto.
An initiator is positioned within the stamped body portion and is secured in place thereon by a sleeve that encloses the initiator and is welded or otherwise connected to the body portion on the side thereof opposite to that of the connector portion. The assembled initiator and igniter body may then be positioned within the open end of a hybrid inflator housing and connected thereto by welding or the like, thereby eliminating the need for a separate igniter housing currently used in many inflator constructions. The connector portion may be provided with a 360° undercut to enable it to receive connector modules of different constructions.
The body portion 12 comprises a central opening 20 for receiving an initiator (not shown). The opening 20 may be outwardly tapered to match the shape of the adjacent portion of the initiator to be positioned therein.
The connector portion 16 may comprise one or more recesses 22 that open into a 360° inner recess or undercut 24 for receiving a power or connector module (not shown) for the initiator (not shown).
Since the body portion 12 is stamped to modify grain structure, gas leaks therethrough are significantly reduced or eliminated. The body portion 12 may be formed of any suitable metal, such as low carbon steel or high strength alloy steels. The connector portion 16 may be formed of any suitable plastic, depending upon the environment to which it will be subjected, such as Nylon, PPS or a polamide. Because the connector portion 16 is molded, it can be provided with any suitable orientation features other than the recesses 22 for positioning a power or connector module therein. Also, the molded connector portion 16 offers protection from metal slivers or the like which can be introduced inadvertently during assembly to the module and thus will protect against insulation resistance issues.
From the foregoing description, it will be readily seen that the igniter bodies 10, 30 and 50 of the present invention are simple in construction, easy to manufacture and assemble, and also easily to connect to the hybrid inflator housing after an initiator has been secured thereto. Also, the molded plastic connector portion of each igniter body can be easily constructed to provide for the connection and orientation of a power or connector module and also to prevent rotation of the module once it is connected to the molded plastic connector portion and to the initiator. The new and improved igniter bodies of the present invention eliminate the need for a separate initiator housing used in many airbag inflators at the present time.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
