1. Field of the Invention
The present invention relates to vehicle passenger safety modules that use pressurized gas from an inflator to deploy an airbag cushion between passengers and the interior of a vehicle in the event of a collision. More particularly, the present invention relates to the interface between the inflator and the airbag in such vehicle passenger safety modules.
2. Background
A typical airbag for a vehicle passenger safety module includes an inflation portion that captures pressurized gas from an inflator, thereby becoming a gas-filled cushion that can be interposed between a vehicle occupant and the interior vehicle surfaces surrounding that occupant. The inflator is ignited electrically in response to a momentum monitor carried in the vehicle.
One end of the inflator produces pressurized gas, while the other, the discharge end of the inflator, emits the pressurized gas into the airbag. If the airbag is complex or extensive, as for example is the case with curtain airbags that inflate at the sides of the passenger compartment, the discharge end of an associated inflator may incorporate a gas guide for directing the pressurized gas in directions and in quantities that are optimally suited to efficiently inflating the airbag.
To effect an attachment between an inflator and an associated airbag, the airbag includes a sleeve-like inlet portion that communicates pneumatically at one end thereof with the inflation portion of the airbag. The opposite end of the inlet portion of the airbag opens to the outside of the airbag. When the elements of a vehicle passenger safety module are assembled in a vehicle, the open end of the inlet portion is advanced over and secured to the exterior of the discharge end of the inflator. The attachment between the inlet portion of an airbag and the discharge end of an inflator is desirably both mechanically secure and pneumatically sealed.
According to teachings of the present invention, an airbag in a vehicle passenger safety module deployed by pressurized gas emitted from the discharge end of an inflator of the safety module includes an inflation portion in which to capture pressurized gas from the inflator, an inlet portion pneumatically communicating with the inflation portion and configured to receive and to be secured to an outer surface of the discharge end of the inflator, and an elastomeric gasket carried on an interior surface of the inlet portion at a location opposing the outer surface of the discharge end of the inflator, when the discharge end of the inflator is received into the inlet portion. The gasket, which is made of cured liquid silicone adhesive, is substantially continuous, thereby to circumscribe the discharge end of the inflator under such circumstances. The transverse extent of the gasket is substantially smaller than the longitudinal extent thereof, while the thickness of the gasket is greater than the thickness of the wall of the inlet portion of the airbag upon which the gasket is carried.
In one aspect of the present invention, a coupling structure for effecting the interconnection between an inflator and an airbag in a vehicle passenger safety module takes the from of a cured band of liquid sealant that is disposed between an exterior surface of a discharge end of the inflator and an interior surface of an inlet portion of the airbag. The cured band is carried on the interior surface of the inlet portion of the airbag, secured directly thereto, thereby to circumscribe the discharge end of the inflator.
The cured band, which may be made of cured liquid silicone adhesive, is substantially continuous in longitudinal extent, has a transverse extent that is substantially smaller than the longitudinal extent thereof, and exhibits a thickness that is greater than the thickness of the wall of the inlet portion of the airbag.
Yet another aspect of the present invention provides a method for manufacturing a vehicle passenger safety module airbag of the type that includes an inlet portion configured to receive the discharge end of the inflator of the safety module. A substantially continuous band of curable liquid sealant is formed against an interior surface of the inlet portion of the airbag at a location opposing and circumscribing the outer surface of the discharge end of the inflator, when the discharge end of the inflator is received into the inlet portion of the airbag. The band of liquid sealant is cured to produce an elastomeric gasket carried on the interior surface of the inlet portion of the airbag. The gasket engages the outer surface of the discharge end of the inflator, when the discharge end of the inflator is received into the inlet portion of the airbag. The curable liquid sealant may be a liquid silicone adhesive.
Where the inlet portion of the airbag is made up of first and second circumferentially-defined neck segments of respective first and second flexible constituent airbag panels, the continuous band of curable liquid sealant is formed by initially applying a first bead of curable liquid sealant to an interior surface of the first neck segment in substantial alignment with a circumferential direction about the inlet portion of the airbag. Then an elongated mandrel having substantially parallel edges is disposed against the first bead of the sealant in longitudinal alignment with the neck segment. This produces from the first bead of sealant a first band of the sealant. A second bead of the sealant is applied to the side of the mandrel opposite from the first bead of sealant in substantial alignment therewith. An interior surface of the second neck segment is then urged against the second bead of the sealant with the second neck segment in longitudinal alignment with the first neck segment. This in turn produces a second band of the sealant from the second bead of sealant. The first neck segment is secured to the second neck segment along respective of the edges of the mandrel, forming the inlet portion of the airbag.
The first band of the sealant and the second band of the sealant together form a substantially continuous band of the sealant, and the step of curing is conducted with the mandrel between the first neck segment and the second neck segment contacting and circumscribed by that substantially continuous band of the sealant. Curing produces from the substantially continuous band of liquid sealant an elastomeric gasket that adheres to the first neck segment and to the second neck segment, but that is nondestructively disengageable from the mandrel. Consequently, the mandrel can be extracted from the center of the gasket and withdrawn from the inlet portion of the airbag.
The mandrel has a width measured transverse the longitudinal extent thereof that is substantially greater than the thickness thereof. The perimeter of a transverse cross section of the mandrel is generally greater than or approximately equal to the perimeter of a transverse cross section of the discharge end of the inflator that is intended to be assembled with the airbag produced in the manner described.
In order that the manner in which the above-recited and other features and advantages of the present invention are obtained will be readily understood, a more particular description of the present invention briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the present invention and are not therefore to be considered to be limiting of the scope thereof, the present invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of embodiments of the present invention, as represented in
Coupling structure 16 includes an attachment bracket 42 having a planar base plate 44, a curved first retention strap 46, and spaced apart therefrom a curved second retention strap 48. First retention strap 46 and second retention strap 48 are integrally-formed with base plate 44, projecting from a lower edge thereof that is obscured in
Toward those ends, an inflator-airbag interface, such as coupling structure 16, is provided according to teachings of the present invention with an elastomeric gasket that is carried on an interior surface of inlet portion 22 of airbag 12 at a location that opposes exterior surface 25 of discharge end 26 of inflator 14, when discharge end 26 of the inflator 14 is received into inlet portion 22 of airbag 12. In interface subassembly 41, such a gasket thus becomes sandwiched between exterior surface 25 of inflator 14 and an interior surface of inlet portion 22 of airbag 12. While not directly visible in
Gasket 60 is a substantially continuous cured band of a liquid sealant, such as a silicone adhesive. As a result, gasket 60 has material properties that enable inner surface 62 thereof to effect a purchase on exterior surface 25 of inflator 14 that is both mechanically secure and pneumatically sealing. Being secured to interior surface 62 of airbag 12, gasket 60 is carried by airbag 12 during the assembly of discharge end 26 of inflator 14 into inlet portion 22. This reduces the number of individual components that must be processed to render safety module 10 operative in a passenger vehicle.
Toward those ends, an inflator-airbag interface, such as coupling structure 70, includes elastomeric gasket 60 (see
First airbag panel 28 includes first neck segment 38, as well as a first inflation segment 90. First inflation segment 90 of first airbag panel 28 eventually serves as a wall of inflation portion 20 of airbag 12. As seen in
Second airbag panel 30 includes second neck segment 40, as well as a second inflation segment 100. Second inflation segment 100 of second airbag panel 30 eventually serves as a wall of inflation portion 20 of airbag 12. As seen in
Next, as shown in
The outer surface of mandrel 112 is possessed of such material properties as will permit mandrel 112 to be nondestructively removed from first broad band 120 of curable liquid adhesive, once the adhesive therein has been cured. A covering of untreated nylon fabric on the exterior of mandrel 112 functions satisfactorily relative, for example, to a liquid silicone adhesive. Mandrel 112 is a generally planar structure. The width of mandrel 112 measured transverse the longitudinal extent thereof, between side edges 114, 116, is substantially greater than the thickness of mandrel 112 measured normal to that longitudinal extent. In addition, the perimeter of a transverse cross section of mandrel 112 is usually less than the perimeter of a transverse cross section of the discharge end of the inflator with which airbag 12 is intended to be assembled.
Then, as shown in
Next, as shown in
Compressive processing forces directed normal to the plane of
Accordingly, as suggested by arrow A in
Commencing at initiation oval 132, method 130 includes the steps set forth in subroutine rectangle 134 of forming a substantially continuous band of curable liquid sealant, such as a curable liquid silicone, against an interior surface of the inlet portion of the airbag at a location opposing and circumscribing the outer surface of the discharge end of an inflator, when the discharge end of the inflator is received into the inlet portion of the airbag. Thereafter method 130 involves the step shown in instruction rectangle 136 of curing the substantially continuous band of liquid sealant into an elastomeric gasket that is carried on the interior surface of the inlet portion of the airbag. Then the mandrel may be disengaged from the gasket 148, leaving the gasket engaging the outer surface of the discharge end of the inflator, when the discharge end of the inflator is received into the inlet portion of the airbag.
In method 130, the inlet portion of the airbag typically includes first and second circumferentially-defined neck segments of respective first and second flexible constituent airbag panels. Employing such first and second neck segments, the forming step of subroutine rectangle 134 begins, as suggested in instruction rectangle 138, with the step of applying a first bead of curable liquid sealant to an interior surface of the first neck segment in substantial alignment with a circumferential direction about the inlet portion of the airbag. Method 130 continues, as suggested in instruction rectangle 140, by disposing an elongated mandrel having substantially parallel edges against the first bead of the sealant in longitudinal alignment with the neck segment. This forms from the first bead of sealant a first band of the sealant. Thereafter, as indicated in instruction rectangle 142, a second bead of the sealant is applied to the side of the mandrel opposite from the first bead of sealant in substantial alignment with the first bead of the sealant. As indicated in instruction rectangle 144, an interior surface of the second neck segment is urged against the second bead of the sealant with the second neck segment in longitudinal alignment with the first neck segment. This forms from the second bead of sealant a second band of the sealant.
Following the forming step of subroutine rectangle 134, but before the curing step of instruction rectangle 136, the first neck segment is secured to the second neck segment along respective of the edges of the mandrel, as suggested in instruction rectangle 146. The first neck segment and the second neck segment thereby form the inlet portion of the airbag under production.
The first band of the sealant and the second band of the sealant together form the substantially continuous band of the sealant called for in subroutine rectangle 134. Accordingly, the curing step of instruction rectangle 136 is conducted with the mandrel between the first neck segment and the second neck segment contacting and circumscribed by the substantially continuous band of the sealant. The step of curing the substantially continuous band of liquid sealant produces an elastomeric gasket that adheres to the first neck segment and to the second neck segment, but that is nondestructively disengageable from the mandrel. Accordingly, as suggested by instruction rectangle 148, the mandrel is disengaged from the center of the gasket and withdrawn from the inlet portion of the airbag under production, and method 130 concludes at termination oval 150.
The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.