Apparatus including an inflatable knee bag

An apparatus (10) helps to protect an occupant (12) of a vehicle (14) having an instrument panel (34) by preventing a forceful impact between lower portions (48) of legs (50) of the occupant (12) and the instrument panel (34) during a vehicle collision. The apparatus (10) comprises an inflator (18) that is actuatable for providing inflation fluid and an inflatable vehicle occupant protection device (20) for receiving inflation fluid from the inflator (18). The protection device (20) inflates from a stored condition to an inflated condition (46) engaging the lower portions (48) of legs (50) of the occupant (12). The protection device (20), when in the stored condition, includes a rolled lower portion (176) and an upper portion (178) that is folded into a stack (180) of pleated sections.

TECHNICAL FIELD

The present invention relates to an apparatus including an inflatable vehicle occupant protection device and, more particularly, to an apparatus including an inflatable knee bag.

BACKGROUND OF THE INVENTION

It is known to inflate an inflatable knee bag between an instrument panel of a vehicle and lower portions of an occupant's legs for helping to protect the occupant during a crash condition. A conventional inflatable knee bag forms a portion of an inflatable knee bag module that is attached to the instrument panel of the vehicle.

Positioning of an inflatable knee bag module on the driver's side of the vehicle requires consideration of the steering column of the vehicle. Since the steering column extends outwardly of the instrument panel of the vehicle, the space available on the instrument panel for attaching the inflatable knee bag module is limited. As a result, the inflatable knee bag module may be attached to the instrument panel in a position that is offset to one side of the steering column. When actuated, it is desirable for the inflatable knee bag of an offset inflatable knee bag module to inflate laterally past the steering column so that the inflated knee bag is located between the instrument panel and the lower portions of both legs of the occupant. It is also desirable for the inflatable knee bag to inflate into a location between the instrument panel and knees of the occupant.

SUMMARY OF THE INVENTION

The present invention relates to an apparatus for helping to protect an occupant of a vehicle having an instrument panel by preventing a forceful impact between lower portions of legs of the occupant and the instrument panel during a vehicle collision. The apparatus comprises an inflator that is actuatable for providing inflation fluid and an inflatable vehicle occupant protection device for receiving inflation fluid from the inflator and inflating from a stored condition to an inflated condition engaging the lower portions of legs of the occupant. The inflatable vehicle occupant protection device includes upper and lower portions. The lower portion is rolled and the upper portion is folded into a stack of pleated sections when the vehicle occupant protection device is in the stored condition.

According to another aspect, the present invention relates to an apparatus for helping to protect an occupant of a vehicle having an instrument panel by preventing a forceful impact between lower portions of legs of the occupant and the instrument panel during a vehicle collision. The apparatus comprises a reaction plate that is attached to the instrument panel of the vehicle and that includes structure defining a cavity having an opening. The apparatus also comprises an inflator and an inflatable vehicle occupant protection device. The inflator is located in the cavity and is secured to the structure of the reaction plate. The inflator is actuatable for providing inflation fluid. The inflatable vehicle occupant protection device, in response to receiving inflation fluid, inflates from a stored condition within the cavity to an inflated condition engaging the lower portions of legs of the occupant. The inflatable vehicle occupant protection device, when in the stored condition, includes a stack of pleated sections that extends upwardly from a rolled portion. The apparatus further comprises a cover for covering the opening of the cavity for protecting the inflatable vehicle occupant protection device when the inflatable vehicle occupant protection device is in the stored condition. The cover includes a portion that is rupturable by the inflatable vehicle occupant protection device to enable expansion of the inflatable vehicle occupant protection device from the stored condition to the inflated condition.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an apparatus10for helping to protect an occupant12(FIG. 2) of a vehicle14(FIG.2). As shown inFIG. 1, the apparatus10includes a knee bag module16. The knee bag module16includes an inflator18and an inflatable knee bag20. The inflator18is actuatable to provide inflation fluid for inflating the inflatable knee bag20from a stored condition within the knee bag module16to an inflated condition for helping to protect the occupant12of the vehicle14.

The apparatus10ofFIG. 1also includes a crash sensor22for sensing a vehicle crash condition and for providing a signal indicative of the vehicle crash condition to vehicle electronics24. The vehicle electronics24include a controller26that receives the signal from the crash sensor22. The controller26runs an algorithm for determining whether the inflatable knee bag20should be actuated in response to the signal from the crash sensor22. When the controller26determines that inflation of the inflatable knee bag20is desirable, the controller26outputs an actuation signal to the inflator18of the knee bag module16. The inflator18includes an igniter28that, in response to the actuation signal, actuates the inflator18to provide inflation fluid.

The inflator18is in fluid communication with the inflatable knee bag20. Inflation fluid provided by the inflator18flows into the inflatable knee bag20and inflates the inflatable knee bag from the stored condition, shown by solid lines inFIG. 3, to the inflated condition, shown by dashed lines in FIG.3.

FIG. 2illustrates, in cross-section, a driver's side30of the vehicle14that includes an apparatus10constructed in accordance with the present invention. The vehicle14includes a passenger compartment32. An instrument panel34(FIG. 3) is located on a front side of the passenger compartment32. The front side of the vehicle14is illustrated as being into the plane of FIG.2and to the left in FIG.3.

The driver's side30of the passenger compartment32includes a driver's seat36, shown by dashed lines, which faces the instrument panel34of the vehicle14.FIG. 2illustrates an imaginary plane38, which extends longitudinally through the vehicle14, i.e., into and out of the plane ofFIG. 2, and defines a centerline of the driver's seat36. Throughout this description, the term “outboard side” refers to a location to the left of plane38, as viewed inFIG. 2, and the term “inboard side” refers to a location to the right of plane38, as viewed in FIG.2. As illustrated inFIG. 2, the plane38also passes through the steering column40and a center of the steering wheel42of the vehicle14.

FIG. 2illustrates schematically the apparatus10associated with the driver's seat36of the vehicle. The knee bag module16, shown schematically inFIG. 2, of the apparatus10is located within the instrument panel34of the vehicle14. The center of the knee bag module16is offset to the outboard side of plane38.FIG. 2also illustrates the inflatable knee bag20in an inflated condition, indicated at46. When in the inflated condition46, the inflatable knee bag20is centered relative to plane38.

FIG. 3illustrates, in section, the knee bag module16mounted in the instrument panel34of the vehicle14. When in the inflated condition46, the inflatable knee bag20is located between the instrument panel34and the lower portions48of the occupant's legs50. Only one leg is shown in FIG.3. The inflatable knee bag20, when in the inflated condition46, helps to protect the occupant12by preventing a forceful impact between the lower portions48of the legs50of the occupant12and the instrument panel34during a vehicle collision.

During inflation of the inflatable knee bag20from the stored condition to the inflated condition46, the inflatable knee bag20expands laterally (to the right as viewed inFIG. 2) across plane38so that in the inflated condition46the inflatable knee bag is located between the instrument panel34and the lower portions48of both legs50of the occupant12of the driver's seat36. During the lateral expansion of the inflatable knee bag20, interference with the steering column40is avoided.

FIG. 3illustrates the steering column40and steering wheel42of the vehicle14. The steering column40extends outwardly of the instrument panel34along plane38, as shown in FIG.2. The knee bag module16illustrated inFIGS. 2 and 3is offset to the outboard side of the steering column40and below the steering column. As shown inFIG. 2, a portion of the knee bag module16extends to the inboard side of plane38.

The knee bag module16includes a reaction plate60for securing the knee bag module to structure of the vehicle14within the instrument panel34. The reaction plate60illustrated inFIGS. 3 and 4is formed from metal. As shown inFIG. 4, the reaction plate60includes a generally rectangular plate portion62having a front surface64and an opposite rear surface (not shown). The rear surface of the plate portion62is presented toward the passenger compartment32of the vehicle14. The plate portion62of the reaction plate60includes an upper edge66, a lower edge68, an inboard edge70, and an outboard edge72. As shown inFIG. 4, the upper edge66of the plate portion62includes a semi-circular cutout74for receiving a portion of the steering column40of the vehicle14.

A trough80is located adjacent the lower edge68of the plate portion62of the reaction plate60. The trough80extends outwardly of the front surface64of the plate portion62. The trough80has a length, indicated at LT, that is defined between first and second side surfaces82and84, respectively. The length LTof the trough80is approximately eighty percent of a length LPof the plate portion62of the reaction plate60. The length LPof the plate portion62is defined as the distance between the inboard and outboard edges70and72. The trough illustrated inFIG. 3is centered on the reaction plate between the inboard and outboard edges70and72of the reaction plate60.

The trough80defines a trapezoidal shaped cavity86(FIG.3). The cavity86of the trough80may have a shape other than trapezoidal, such as cylindrical. An upper wall88, a lower wall90, and an end wall92of the trough80define the trapezoidal shape of the cavity86. As shown inFIG. 3, the upper wall88of the trough80extends outward of the front surface64of the plate portion62of the reaction plate60. The lower wall90of the trough80extends outward of the front surface64of the plate portion62. The end wall92of the trough80connects the upper and lower walls88and90and defines a closed narrow end of the cavity86. An opening is defined between the upper and lower walls88and90opposite the end wall92. The opening forms the widest portion of the cavity86.

As shown inFIG. 4, the trough80includes a shallow portion94and a deep portion96. The deep portion96of the trough80extends outward of the front surface64of the plate portion62of the reaction plate60farther than the shallow portion94. An angled portion98of the end wall92connects the shallow portion94and the deep portion96of the trough80.

Three through-holes100extend through the end wall92of the trough80and open into the cavity86within the deep portion96of the trough. The three through-holes100are spaced from one another along the end wall92.

The inflator18illustrated inFIG. 3is a hybrid inflator and includes a cylindrical housing110. Although a hybrid inflator is preferred, other types of inflators may be used for providing inflation fluid. Two mounting studs112extend outwardly of the cylindrical housing110of the inflator18. A fill valve114extends outwardly of the housing110between the two mounting studs112. The hybrid inflator18is filled with compressed gas through the fill valve114. The fill valve114is sealed after the inflator18is filled to prevent leakage of the gas out of the inflator housing110through the fill valve114.

The cylindrical housing110of the inflator18has first and second circular end walls, only the first end wall being shown at116inFIG. 4. Areceptacle118is formed in the first end wall116of the inflator18. The receptacle118is adapted to receive an electrical connector for connecting the inflator18to the vehicle electronics24.

The knee bag module16also includes a cover120. The cover120illustrated inFIGS. 3 and 4is molded from plastic. The cover120is adapted to overlie the plate portion62of the reaction plate60of the knee bag module16and to cover the opening into the cavity86, as is shown in FIG.3. The cover120is generally rectangular and has a configuration and dimensions similar to the configuration and dimensions of the plate portion62of the reaction plate60. As shown inFIG. 4, the cover120includes an upper edge122, a lower edge124, an outboard edge126, and an inboard edge128. A semicircular cutout130is removed from the upper edge122of the cover120near the inboard edge128of the cover120and is positioned to correspond to the position of the cutout74in the plate portion62of the reaction plate60.

The cover120also includes a front surface132and rear surface134(FIG.3). The front surface132of the cover120is adapted to be attached to the rear surface of the plate portion62of the reaction plate60. The rear surface134of the cover120is visible to the occupant12of the vehicle14and may be designed to blend aesthetically with the instrument panel34.

The cover120includes a tear seam136. The tear seam136has an inverted U-shape that includes two leg portions138and140, respectively, and an interconnecting portion142that extends between the two leg portions138and140of the tear seam. The two leg portions138and140of the tear seam136are positioned on the cover120in locations corresponding to the locations of the first and second side walls82and84of the trough80of the reaction plate60. The interconnecting portion142of the tear seam136is positioned on the cover120in a location corresponding to the location of the upper wall88of the trough80, adjacent the opening to the cavity86. When subjected to a predetermined force, the tear seam136is adapted to open to form a flap that may be bent downwardly toward the lower edge124of the cover120. Bending the flap downwardly provides an opening in the cover that is approximately the same size as the opening to the trough80of the reaction plate60.

The inflatable knee bag20is illustrated inFIGS. 5A-5F. The inflatable knee bag20is formed from a single piece of material that is folded upon itself and stitched around three edges to form a generally rectangular bag. The inflatable knee bag20includes front and rear panels150and152, respectively. The front and rear panels150and152are sewn together along a lower edge154, an inboard edge156, and an outboard edge158of the inflatable knee bag20. A fold that separates the front and rear panels150and152of the inflatable knee bag20forms an upper edge160of the inflatable knee bag. The front panel150of the inflatable knee bag20includes a portion162(FIG. 5D) for receiving the inflator18. Three holes (not shown) extend through the front panel150of the inflatable knee bag20for receiving the mounting studs112and the fill valve114of the inflator18. Preferably, the inflator18is positioned within the inflatable knee bag20through an opening (not shown) on the outboard edge158of the inflatable knee bag20. The opening in the outboard edge158of the inflatable knee bag20is then sewn closed after the inflator18is received within the inflatable knee bag.

The inflatable knee bag20also includes two tethers164that connect the front and rear panels150and152. Each tether164is formed from an elongated piece of fabric material and includes opposite first and second ends166and168, respectively. A first end166of each tether164is sewn to the front panel150of the inflatable knee bag20and a second end168of each tether is sewn to the rear panel152of the inflatable knee bag. The tethers164help to maintain a fixed distance between the front and rear panels150and152when the inflatable knee bag20is in the inflated condition46, which results in flattening of the inflated knee bag.

The inflatable knee bag20is stored within the cavity86of the trough80of the reaction plate60when in a stored condition.FIGS. 5A-5Fillustrate a method of compacting the inflatable knee bag20into the stored condition.

As a reference, the dashed box shown inFIGS. 5A and 5Bis the opening to the cavity86of the trough80of the reaction plate60. The inflator18is also illustrated inFIGS. 5A and 5B.

To compact the knee bag20into the stored condition, the knee bag20is laid flat with the rear panel152overlying the front panel150. The knee bag20is then folded by moving the inboard edge156of the knee bag20laterally toward the outboard edge158, in the direction indicated by arrow170inFIGS. 5A-5B, until the inboard edge156extends slightly beyond the center of the knee bag. After forming this first fold, the inboard edge156is moved laterally outwardly until the inboard edge aligns with the first fold line, as shown inFIGS. 5B and 5C. The lower edge154of the inflatable knee bag20is then rolled upwardly, indicated by arrow172inFIG. 5B, in a direction toward the front panel150so that the rear panel152of the inflatable knee bag forms an outer surface174of a rolled lower portion176of the inflatable knee bag20, as is shown in FIG.5D. The lower portion176of the inflatable knee bag20is defined between the lower edge154and a center of the inflator receiving portion162in the inflatable knee bag.

An upper portion178of the inflatable knee bag20is defined between the upper edge160and a center of the inflator receiving portion162in the inflatable knee bag. The upper portion178of the inflatable knee bag20is formed into a stack180(FIG. 5F) of pleated sections. To form the stack180of pleated sections, the upper portion178of the inflatable knee bag20is zigzag folded, as shown in FIG.5E.

The stack180of pleated sections includes a first plurality of pleated sections182formed by portion of the rear panel152of the inflatable knee bag20. Each pleated section182of the first plurality of pleated sections182includes upper and lower laterally extending pleat surfaces184and186, respectively, that are separated by a laterally extending pleat fold188. The pleat fold188forms the rearmost portion of each pleated section182.

The stack180of pleated sections also includes a second plurality of pleated sections190formed by portions of the front panel150of the inflatable knee bag20. Each pleated section190of the second plurality of pleated sections190includes upper and lower laterally extending pleat surfaces192and194, respectively, that are separated by a laterally extending pleat fold196. The pleat fold196forms the rearmost portion of each pleated section190. Preferably, each of the upper and lower laterally extending surfaces184,186,192, and194of the pleated sections182and190has a width, indicated generally as W inFIG. 5F, of approximately 23-25 millimeters.

Each pleated section182of the first plurality of pleated sections182has an associated pleated section190of the second plurality of pleated sections190. The pleated section182receives the associated pleated section190so that the upper and lower laterally extending surfaces192and194of the associated pleated section190are interposed between upper and lower laterally extending surfaces184and186of the pleated section182.

The stack180of pleated sections is compacted and positioned above the rolled lower portion176of the inflatable knee bag20. The stack180of pleated sections and the rolled lower portion176of the inflatable knee bag20are then positioned immediately adjacent to and rearward of the inflator18to place the inflatable knee bag in the stored condition, shown in FIG.5F. When in the stored condition, the stack180of pleated sections begins near the center of the inflator18and extends upwardly. The inflatable knee bag20, when in the stored condition, may be wrapped with a rupturable wrap (not shown) to help maintain the inflatable knee bag in the stored condition.

The reaction plate60of the knee bag module16is attached to the instrument panel34so that the opening of the cavity86in the trough80of the reaction plate opens rearward into the passenger compartment32. The inflatable knee bag20, in the stored condition, and the inflator18, which is positioned in the inflatable knee bag, are positioned within the cavity86in the deep portion96of the trough80. The mounting bolts112and fill valve114of the inflator18are received in the through-holes100of the end wall92of the trough80. Nuts200(FIG. 4) are screwed onto the mounting bolts to secure the inflator relative to the reaction plate60. Rubber washers (not shown) may be positioned over the mounting bolts112for creating a seal between the reaction plate60and the inflator housing110and for sealing the bolt holes in the inflatable knee bag20when the inflator18is secured to the reaction plate.

After securing the inflator18to the reaction plate60, the inflatable knee bag20, in the stored condition, is positioned in the cavity86of the trough80. When stored in the cavity86, the pleat folds188of the first plurality of pleated sections182lie adjacent the opening of the cavity186of the trough80. The stack180of pleated sections extends along the opening of the cavity186from the center of the inflator18to a position adjacent the upper wall88of the trough80. The rolled lower portion176of the inflatable knee bag20is positioned adjacent the opening of the cavity86near the lower wall90of the trough80.

The cover120is then positioned over the reaction plate60and is secured to the plate portion62of the reaction plate60. The cover120closes the opening of the cavity86and overlies the inflatable knee bag20when the inflatable knee bag is in the stored condition within the cavity to protect the inflatable knee bag from damage. When the cover120is secured to the reaction plate60, the tear seam136of the cover120is located near the top of the stack180of pleated section, as shown in FIG.3.

When the inflator18of the apparatus10is actuated, inflation fluid provided by the inflator18enters the inflatable knee bag20. In response to receiving inflation fluid, the stack180of pleated sections begins to inflate. When the pressure within the stack180of pleated sections reaches a predetermined pressure, the expanding knee bag20causes the tear seam136in the cover120to open. The stack180of pleated sections then expands outward of the cavity86of the reaction plate60and upward between the instrument panel34and the lower portion48of the legs50of the occupant12.

After the stack180of pleated sections begins to inflate, the rolled lower portion176of the inflatable knee bag20begins to unroll and expand downward between the instrument panel34and the lower portions48of the legs50of the occupant12. During inflation of the lower and upper portions176and178of the inflatable knee bag20, the laterally inwardly folded portion (shown inFIGS. 5B and 5C) of the inflatable knee bag is inflated. The inflatable knee bag20inflates laterally in an inboard direction as the laterally inwardly folded portion of the inflatable knee bag is inflated to ensure that the lower portions48of both legs50of the occupant12are protected.

When inflation of the inflatable knee bag20is complete, the inflatable knee bag20is in an inflated condition46. In the inflated condition46, the center of the inflatable knee bag20of the apparatus10is located in plane38, as shown in FIG.2.