Patent Application
20060061068
During the operation of a motor vehicle, the driver may often experience vibrations transmitted through the steering wheel of the vehicle. Such vibrations may commonly be caused by situations such as a poor road surface, improper alignment or adjustment of the vehicle tires, or other mechanical conditions. This vibrational feedback does not generally present a hazard to the driver of the vehicle. In some situations however, vibration may render steering the vehicle difficult, and lower the driver's ability to control the vehicle. In addition, vibrations received through the steering wheel may become distracting to the driver, and thus may prevent the vehicle driver from noticing other hazards on the road or from otherwise properly focusing their attention on the task of driving. Such conditions may increase the likelihood of a vehicle accident.
Modern steering wheels and steering columns are often constructed using a vibrational damper to reduce the amount of steering wheel vibration experienced by a driver. Known dampers include a mass of metal mounted within the steering column in such a way that it is allowed to oscillate or move to absorb some of the vibrations transmitted through the steering column. This mass of metal or “attenuation mass” is generally mounted to the steering column by an elastic member which allows it to move as described. When vibration is passed to the steering column, it is passed to the “attenuation mass” which operates to dampen the vibration passed through the steering wheel to the driver.
Recently, there has been a movement in the airbag module industry to utilize already existing components of the steering wheel and/or steering column as the attenuation mass for a vibration damper system. One suitable mass is the inflator of an airbag module. In order to use the inflator of an airbag module as the attenuation mass, the inflator must be mounted within the airbag module in such a way that it is permitted to vibrate or move in response to vibrations transmitted to the inflator through the steering column. When properly mounted, air bag inflators function very similarly to the attenuation mass previously used in such vibration damper systems. This also results in an overall reduction of components within a steering wheel and steering column assembly and thus may reduce the cost required for this portion of the vehicle.
Several challenges have been faced in using an airbag inflator as an attenuation mass provided to dampen vibrations in the steering column. Once such difficulty is providing a proper mounting for the inflator that will hold the inflator in place during both storage and operation of the airbag module that properly allows movement of the inflator to dampen the vibrations. Several solutions to this problem have been provided, but engineers have been additionally faced by the challenge of properly grounding the inflator module so as to prevent accidental, improper, or unintended activation of the inflator by the presence or buildup of electrical charges such as those provided by static electricity, lightning or other sources. Without proper grounding, such electrical sources could trigger initiation of the inflator, deploying an air bag in an unexpected and potentially dangerous fashion.
Grounding has been provided by running a grounding wire from the inflator to another metal portion of the steering wheel or steering column. This solution is problematic in that because the inflator's use as a attenuation mass, it will vibrate, subjecting the wire to wear, repetitive movement, and strain that may result in breakage of the wire, damage to the inflator, or simply improper grounding. This could be dangerous for the reasons outlined above.
As a result, it would be a benefit in the art to provide a structure for mounting an airbag inflator in a vehicular steering wheel/steering column assembly for use as an attenuation mass that allows the inflator to vibrate in response to the steering column, while also permitting the inflator to be properly and durably grounded. Such a device, airbag modules incorporating such a device, methods of their use, and steering wheels incorporating such a device are disclosed herein.
The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available systems for damping vibration in steering columns. Thus, the present invention provides a novel mounting structure for an airbag inflator that allows the inflator to be used as a damper for vibrations transmitted through the steering column of a vehicle.
In a first embodiment, the invention provides a vibration damper gasket for use in an inflatable airbag module mounted in the steering column of a vehicle. The vibration damper gasket of the invention includes a mounting ring sized, shaped, and configured to fit about the edge of the flange of an airbag inflator. The mounting ring has upper and lower retention arms and an adapter groove positioned between the retention arms. The adapter groove is sized to receive the edge of the airbag inflator flange. The retention arms and adapter groove are supported by a compression column provided on an outside surface of the mounting ring. The vibration damper gasket further includes an inflator ground extending along an inside surface of the mounting ring from at least an upper contact surface of the upper retention arm continuously across the adapter groove to a lower contact surface of the lower retention arm. The inflator ground serves to ground the airbag inflator within the steering column assembly.
In a first configuration, the vibration damper gasket may include a mounting ring produced as a monolithic elastomeric ring. In producing the monolithic mounting ring, the adapter groove is sized to accommodate the edge of an airbag inflator flange. In some instances, the adapter groove of the vibration damper gasket is sized to be slightly smaller than the edge of an airbag inflator flange. In others, the adapter groove of the vibration damper gasket is sized to be approximately identical in size to the edge of an inflator flange. In still others, the adapter groove of the vibration damper gasket is sized to be slightly larger in size than the edge of an inflator flange.
These various sizing schemes of the adapter groove regulate the method of attachment of the gasket to the inflator. More specifically, close conformity in size of the groove to the size of the inflator flange regulates the tightness of the fit of the flange into the groove. In some situations, the tightness and depth of the groove may be sufficient to retain the inflator within the gasket alone. In others, it may be desirable to include an adhesive to assure proper retention of the inflator within the gasket. Indeed, it may be desirable to use an adhesive even when a tight fit is provided. A conductive adhesive may be used to help assure proper grounding of the inflator.
In another configuration of the vibration damper gaskets of the invention, the gaskets include non-monolithic mounting rings and a ground. More specifically, the mounting ring is composed of a stacked set of rings, each with a specific size and purpose. The mounting ring thus includes a first elastomeric ring having a module plate contact surface, an inflator flange support surface, and an adapter interface surface. This ring rests on the module plate and serves as a support for the mounting ring. The mounting ring next includes an elastomeric adapter ring having an interior diameter adapted to conform to the edge of the airbag inflator flange. This adapter ring is placed atop the first elastomeric ring. The mounting ring finally includes a second elastomeric ring having a contour plate contact surface, an inflator flange support surface, and an adapter interface surface. This ring is placed atop the adapter ring and is the structure that has direct contact with the contour plate of the airbag module.
In yet another configuration, the mounting ring of the vibration damper gaskets of the invention may take the form of a strip configured to be wrapped about the flange of the airbag inflator. The strip includes upper and lower retention arms and an adapter groove positioned between the retention arms for receiving the edge of the airbag inflator flange. The retention arms and adapter groove of the strip are supported by a compression column provided on an outside surface of the mounting ring. In use, the strip making up the mounting ring of the gasket is wrapped about an inflator and cut to size to accurately accommodate the inflator. The use of a strip allows free accommodation of the vibration damper gasket to a wide variety of inflators with varying sizes, flange sizes, flange shapes, and flange geometries.
In some instances, the ends of the strip of the vibration damper gasket produced by cutting the strip to size may be attached to each other. This may be accomplished using an adhesive, a fastener, a clamp, or other method or structure known to one of ordinary skill in the art. In some instances, it may be useful to affix the ends to each other using a conductive adhesive.
Each of the vibration damper gaskets of the invention include an inflator ground to assure proper grounding of the airbag inflator, thus preventing unintended deployment resulting from the buildup of an electrical charge, lightning strike, etc. The inflator ground is a conductive layer placed on exterior surfaces of the mounting gasket which may be selected from the group consisting of metal braid, metal wire, metal foil, or carbon fiber. The inflator ground travels from at least a point on an upper surface that is in contact with, or when installed will contact the contour plate, then travel across an interior face of the gasket to a bottom surface that is in contact with, or when installed, will contact the module plate of the airbag module. The ground thus appears to be a strip across a portion of the gasket. The inflator ground may be varied to have different forms, such as rings completely traversing the gasket, or the entire gasket may be ensheathed by the ground. In some instances, the vibration damper gasket may include a plurality of inflator grounds. In specific configurations, the gasket includes at least two inflator grounds.
The vibration damper gaskets of the invention are intended for use with inflatable airbag modules having airbag inflators. Each of the gaskets of the invention is configured to be mounted in a vehicle primarily by compression between a contoured plate and a module plate. Each gasket of the invention has a support column for this purpose. More specifically, the gaskets are constructed to have a support column having a height sufficient to provide a secure fit when the gasket is clamped between the contour and module plates. A secure fit may be provided by adapting the support column of the gasket to have a height either substantially equal to or slightly larger than the height of the space defined between the contoured plate and the module plate when they are attached together. When placed between the contoured and module plates, with the plates attached, the elastomeric nature of the gasket allows it to slightly deform, and its tendency to return to its natural shape provides the pressure needed to hold the inflator in place.
In some configurations, it may be sufficient to provide a vibration damper gasket with a support column slightly smaller than the height of the space defined between the contoured plate and the module plate when they are attached together. This may be the case when either or both of the contour and module plates are provided with surface features that protrude to engage the gasket and retain it in place.
The gasket may be supplementally attached to the contoured plate and/or the module plate using an adhesive such as a conductive adhesive. This may provide additional integrity to the mounted vibration damper gasket, and potentially aid in preventing shifting of the gasket during operation of the vehicle.
In order that the manner in which the above-recited and other features and advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the 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 the embodiments of the vibration damper gasket of the present invention, as represented in
Referring first to
The airbag module 14 of
The cavity 18 of the airbag module 14 further includes a sub-divided inflator cavity 22 separated from the primary cavity 18 by a contour plate 24. The contour plate 24 is designed to be mounted to the module plate 28 and subdivide the primary cavity 18 to enclose an airbag inflator 32. The contour plate 24 also serves to secure the airbag inflator 32 to the vehicle using the inflator gaskets 10 of the invention, as will be discussed in greater detail below.
The airbag inflator 32 is mounted within the inflator cavity 22 of the module 14 so as to allow some movement of the inflator 32 to dampen vibrational energy transmitted through the steering column. More specifically, in the modules 14 of the invention, the inflator 32 is mounted using a vibration damper gasket 10, which suspends the inflator 32 within the inflator cavity 22. The inflator cavity 22 discussed above is defined by the contour plate 24 and the module plate 28. The inflator cavity 22 generally encompasses the airbag inflator 32, which is generally suspended within the cavity 22. The contour plate 24 provides clearance above the inflator 32 to allow movement, while the module plate 28 below the inflator 32 has an orifice 38 to provide clearance below the inflator 32. The inflator orifice 38 generally accommodates protrusion of the body of the inflator 32 from the module 14, but is sufficiently narrow to prevent passage of the inflator flanges 40 through the orifice 38. Thus, the inflator cavity 22 generally provides sufficient clearance to allow movement of the inflator 32 in response to force transmitted to it through a steering column to which the module 14 has been mounted. The inflator orifice 38 is also sufficient in size to allow passage of the electrical connections 36 used to connect the inflator 32 to an accelerometer and/or other associated apparatus commonly used in the art to detect a collision event and trigger initiation of the inflator 32 and deployment of the airbag cushion 20. As described above, the orifice 38 is still small enough to prevent escape of the inflator 32 through the orifice 38.
The vibration damper gasket 10 of
In the embodiment of the gaskets of the invention illustrated in
The width 78 of the groove 76 is determined so as to provide a secure fit to the airbag inflator 32. More specifically, the groove 76 may have a width 78 slightly smaller than a width 46 of the edge 44 of the inflator flange 40. The elastomeric arms 70, 80 may flex slightly and grasp the flange 40 to allow the edge 44 to penetrate sufficiently into the groove 76 to provide a secure fit. Alternatively, the groove 76 may have a width 78 equivalent to the width 46 of the edge 44 of the inflator flange 40 or slightly larger than the width 46 of the edge 44 of the inflator flange 40. In either of these cases, the depth 82 of the groove 76 may be adapted to be sufficient to allow secure retention of the inflator 32, and/or an additional adhesive may be used to secure the inflator 32 in place within the gasket 10.
The gasket 10 further includes a compression column 90 supporting the arms 70, 80 and defining an inner surface of the groove 76. In the embodiment of the gaskets 10 of the invention illustrated in
As illustrated in
The gasket 10 further includes an inflator ground 96 illustrated here as a continuous conductive layer applied about the outer surfaces of the gasket 10. Each of the vibration damper gaskets 10 of the invention include at least one such inflator ground 96 to assure proper grounding of the airbag inflator 32. The inflator ground 96 is a conductive layer placed on the exterior surface of the mounting gasket 10. Suitable materials used to make such a ground 96 may be selected from the group consisting of metal braid, metal wire, metal foil, or carbon fiber. Suitable materials may be attached to the gasket 10 using adhesives or other suitable means known to one of ordinary skill in the art.
In the gaskets 10 of the invention, the inflator ground 96 travels from at least a point on the contact surface 52 of the upper surface 50 of the gasket 10 across the inner surface 62 and its contact surface 64, and to the lower contact surface 60 of the lower surface 58. The ground 96 may also span the rear surface 54. The ground 96 is configured such that when installed, it is at least in contact with the contour plate 24, the inflator flange 40, and the module plate 28. The ground 96 may thus appear as a strip across a portion of the gasket 10. The inflator ground 96 may be varied to have different forms, such as rings completely traversing the gasket, or the entire gasket 10 may be ensheathed by the ground 96. The number and placement of the grounds 96 may also be varied within the scope of the invention. In some instances, the vibration damper gasket 10 may include a plurality of inflator grounds 96. In specific configurations, the gasket 10 includes at least two inflator grounds 96.
Referring next to
As in the airbag module 14 described in
The airbag module 114 of
The primary module cavity 118 of the airbag module 114 further includes a sub-divided inflator cavity 122 separated from the primary cavity 118 by a contour plate 124. The contour plate 124 is designed to be mounted to the module plate 128 by fasteners 130 and thus, to subdivide the primary cavity 118. This effectively encloses the airbag inflator 132 between the contour plate 124 and the module plate 128, and more specifically, the inflator orifice 138 of the module plate 128. The contour plate 124 also serves to secure the airbag inflator 132 to the vehicle using the inflator gaskets 110 of the invention.
The airbag inflator 132 is mounted within the inflator cavity 122 of the module 114 so as to allow some movement of the inflator 132 to dampen vibrational energy transmitted through the steering column. As in the gasket 10 illustrated in
As discussed above, the vibration damper gasket 110 of
The upper and lower rings 150, 170 are generally configured to have an inner circumference (or, in non-circular applications, an inner orifice) similar or equal in size or shape to that of the module plate 128. The center ring 160 has an inner diameter substantially equivalent or slightly larger than that of the inflator flange 140. In this manner, the center ring 160 is sized to fit about a lateral radial flange 140 of the inflator 132 in such a manner that the inflator 132 may be securely supported solely by the gasket 110. The fit of the flange 140 may be adapted by varying the height of the groove 176 defined by the center ring 160. This may be done by varying the height of the center ring 178, and thus of the groove 176. In some configurations, it may be advantageous to provide a groove 176 with a width 178 slightly less than that of the inflator flange 140. Thus, when the flange 140 is inserted into the groove 140, it is grasped by the upper and lower rings 150, 170. Alternatively, the groove 176 may have a width 178 substantially equivalent to, or slightly larger than, the outer diameter/size of the flange 140. In some instances, it may be useful to provide an adhesive to assist in retaining the flange. In some instances, it may be specifically useful to use a conductive adhesive. In this gasket 110, a support column 190 having a height 194 is composed of outer portions of all three of the rings 150, 160, 170.
Thus, the gasket 110 is generally a composite elastomeric ring configured to fit about an outer edge 144 of the radial flange 140 of the airbag inflator 132. The gasket 110 of
Use of suitable elastomeric materials in preparing the gasket 110 also provides some flexibility in accommodating a variety of flange shapes with the gasket 110. As with the gasket 10 of
As with the previously-discussed embodiment, the vibration damper gasket 110 is configured to house an inflator flange 140 within a groove 176 defined by the upper and lower rings 150, 170. The depth 182 of the groove 176 is adapted to provide sufficient surface area of the upper and lower rings 150, 170 to adequately support the mass of the inflator 132. The width 178 of the groove 176 is determined so as to provide a secure fit to the airbag inflator 132. More specifically, the groove 176 may have a width 178 slightly smaller than a width 146 of the edge 144 of the inflator flange 140. The elastomeric upper and lower rings 150, 170 may flex slightly and grasp the flange 140 to allow the edge 144 to penetrate sufficiently into the groove 176 to provide a secure fit. Alternatively, the groove 176 may have a width 178 equivalent to the width 146 of the edge 144 of the inflator flange 140 or slightly larger than the width 146 of the edge 144 of the inflator flange 140. In either of these cases, the depth 182 of the groove 176 may be adapted to be sufficient to allow secure retention of the inflator 132, and/or an additional adhesive may be used to secure the inflator 132 in place within the gasket 110.
As noted briefly above, the gasket 110 includes a composite compression column 190 comprising portions of the upper, center, and lower rings 150, 160, 170, and defining an inner surface of the groove 176. In the gasket 110 of the invention of
As illustrated in
The gasket 110 also includes a pair of inflator grounds 196a, 196b illustrated here as conductive layers applied about the gasket 110. As previously discussed, the inflator grounds 196a, 196b are conductive layers, in this embodiment made as incomplete rings spanning only the upper, inner, and lower surfaces 150, 154, 158 of the gasket 110. Similarly, the materials used to make the grounds 196a, 196b may be selected from the group consisting of metal braid, metal wire, metal foil, or carbon fiber. Suitable materials may be attached to the gasket 110 using adhesives or other suitable means known to one of ordinary skill in the art.
A next embodiment of the invention is illustrated in
As in prior embodiments of the gasket 210, the groove 276 is adapted to be wrapped about an edge of a lateral flange of an airbag inflator (not shown). In this embodiment of the gasket 210, the groove 276 includes a rounded inner contact surface 264 sized and adapted to fit closely about an inflator flange. As in previously discussed embodiments, the groove 276 may be sized to provide a secure fit about the inflator flange. Specifically, the groove 276 may have a depth 282 adapted to provide sufficient surface area in contact with the inflator flange to provide a secure fit. Further, the groove 276 may have a width 278 that is slightly smaller than a width of the inflator flange such that the groove 276 tightly grips the inflator flange. Alternatively, the groove 276 may have a width 278 that is substantially equivalent to the width of the inflator flange, or a width slightly larger than that of the inflator flange. In these two variants, an additional adhesive may be used.
The gasket 210 may further include a compression column 290 sized to have a height adapted to be received and secured into an inflator housing as discussed above with the previous embodiments. Also, as discussed with relation to other gaskets 210 of the invention, the gasket 210 includes an inflator ground 296. In such embodiments of the gaskets 210 of the invention which may be cut-to-size for individual uses, inflator grounds 296 may be placed at intervals (either regular or irregular) along the length of the gasket 210 such that when cut, the gasket includes at least one inflator ground 296. Use of conductive adhesive either in bonding the ends 284a, 284b of the gasket 210 or in attaching the inflator grounds 296 to the gasket 210 may further improve the grounding of the inflator in an airbag module when installed in a vehicle.
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.
