WO2006017131A2

WO2006017131A2 - Automotive bolster

Info

Publication number: WO2006017131A2
Application number: PCT/US2005/024147
Authority: WO
Inventors: Michael James Best; Babak Fana; Raj S. Roychoudhury
Original assignee: Michael James Best; Babak Fana; Roychoudhury Raj S
Priority date: 2004-07-09
Filing date: 2005-07-08
Publication date: 2006-02-16
Also published as: WO2006017131A3

Abstract

An inflatable bolster (50) for vehicle, the bolster (50) comprising a housing (60) the housing (60) defining an internal chamber (51), an upper tether (70) attached to an upper portion of the housing (60), a lower tether (80) attached to a lower portion of the housing (60), wherein the lower tether (80) is extensible so that upon inflation of the chamber (51), the chamber (51) moves upwardly and rearwardly relatively to the upper tether (70).

Description

Title: AUTOMOTIVE BOLSTER

Field of the invention

[0001] This invention relates to the field of safety devices as are often installed in motor vehicles, particularly automobiles. Amongst many safety devices that are installed in vehicles to lessen injuries arising from impact are bolsters. The bolster is typically part of an in instrument panel which lies forward of the legs of an occupant. When the vehicle undergoes rapid deceleration as in a frontal impact, the occupant will move forward and, subject to other safety devices, will contact the instrument panel. In many cases an occupant will be restrained by a seat belt or the occupant's relative forward momentum relative to the vehicle will be absorbed by some type of air bag which may act against the upper torso of the vehicle occupant. In many situations, it is considered desirable to provide crash energy absorption in the area of the instrument panel that might be expected to be contacted by the lower limbs of the vehicle occupant. In order to achieve some energy dissipation and to reduce injuries arising from such impact, the bolster may be padded to absorb energy. An alternative system includes providing an inflation means to the bolster so that the bolster moves aft to a desired position where it can be contacted by the legs of the vehicle occupant. As the legs of the vehicle occupant contact the inflated bolster energy absorption occurs to help reduce injury to the occupant.

Background of the invention

[0002] Examples of inflatable bolsters include the structures illustrated in U.S. patent 6,032,978 and U.S. 6,302,057, the entire contents of which are incorporated herein by reference.. [0003] When an inflatable bolster is designed, the bolster is expected to inflate and to arrive at a desired position. When in the desired position, there is then an intended impact zone. That zone may change depending upon the physical size of the vehicle occupant. Thus, the zone increases in size to satisfy the likely desired point of impact for different percentile occupants. The wider the percentile range of occupants that are intended to be accommodated, the larger the inflatable bolster must be to accommodate those differing sizes. Typically, the aft wall of an inflatable bolster is caused to move rearwardly during inflation. In order to arrive at the desired position, this effectively means that the inflatable bolster must be relatively large in the vertical extent.

Summary of the invention

[0004] In accordance with the present invention, an inflatable bolster has a deployment trajectory which is generally rearward and generally upward. In accordance with one aspect of the invention, the bolster includes a housing with the housing defining a hollow closed chamber. The housing may have an upper tether which is attached to an upper portion of the housing. The housing may also have a lower tether which is attached to a lower portion of the housing. The upper tether is substantially inextensible and the lower tether is extensible so that upon inflation of the chamber within the housing, the inflating chamber moves upwardly and rearwardly with respect to the attachment point between the upper tether and the vehicle support structure.

[0005] In accordance with another aspect of the invention, a bolster includes a housing having an aft wall and a forward wall. The housing may define a closed chamber between the aft and forward walls. The housing has an upper tether for tethering the housing to the vehicle structure. The housing also has a lower extensible tether so that upon inflation of the chamber the aft wall of the housing may move upwardly and rearwardly.

[0006] In accordance with another aspect of the invention, an inflatable bolster may include a housing having a forward wall and an aft wall. In addition, the housing has an upper side wall. The housing defines a closed chamber which may be expanded under the effect of an inflating gas. The upper side wall is in a folded condition so that the aft wall is adjacent the forward wall in the uninflated condition. Upon inflation of the chamber within in the housing, the upper side wall may be expanded by unfolding to provide a generally rearwardly extending, upper side wall when in the inflated condition, thereby moving the aft wall of the chamber rearwardly upon inflation. Brief description of the drawings

[0007] Further and other features of the invention will be apparent from review of the attached drawings which illustrate various embodiments of the invention, and in which: [0008] Figures 1A and 1B are cross-sectional drawings of a first embodiment of the invention, Figure 1A showing the first embodiment in uninflated condition and Figure 1B showing the first embodiment in inflated condition;

[0009] Figure 2 illustrates a second embodiment of the invention in which Figures 2A and 2B are cross-sectional drawings of the second embodiment of the invention, Figure 2A showing the second embodiment in uninflated condition and Figure 2B showing the second embodiment in inflated condition, and

[0010] Figure 3 illustrates a third embodiment of the invention in which Figures 3A and 3B are cross-sectional drawings of the third embodiment of the invention, Figure 3A showing the third embodiment in uninflated condition and Figure 3B showing the third embodiment in inflated condition.

Detailed description of the invention

[0011] Generally speaking, the bolster of the present invention is advantageously deployed in the region where it will deliver impact protection to the driver. The driver may also be provided with other safety related devices such as seat belts or air bags which may be steering wheel mounted.

Typically, the bolster will be arranged so that it is adjacent to the steering column and may extend laterally to either side of the center line of the vehicle steering column so as to provide its impact lessening effects for both legs of the driver.

[0012] The bolster of the current invention may be used at other occupant positions throughout a vehicle. For example, the bolster of the present invention could be used for a front seat passenger. In most cases, the instrument panel immediately in front of a front seat passenger includes a glove box or the like. Thus, bolsters of this type have not traditionally been used because of the need to provide a glove box door. However, if the vehicle structure permits, then the structure of the present invention may be used in any vehicle location including a seat other than the front seat. The invention may be used in any location within the vehicle where it is desirable to provide energy absorption effects desired of such a bolster.

[0013] In explaining the invention in accordance with the embodiments illustrated in Figures 1 through 3, it will be taken by way of example that the bolster is applied to an instrument panel and that the instrument panel is connected to suitable energy absorption structure. In each case, the vehicle structure has been simplified for purposes of explanation by referring to the vehicle structure 10. The vehicle structure 10 may include an upper attachment pocket 12 which may advantageously include a retaining tang 14, the purpose of which will be explained below. In addition, the vehicle attachment structure 10 may also include a lower attachment point indicated generally at 18.

[0014] With respect to Figures 1A and 1 B, the inflatable bolster in accordance with this invention is shown generally at 50. The inflatable bolster 50 includes a general housing 60. The housing 60 includes an aft wall 62 and a forward wall 64. In addition, the housing 60 includes side wall (not shown) in the cross-section and an upper side wall 66 including a plurality of pleats 68 which are shown in the folded condition in Figure 1A. The bolster 50 includes an upper tether 70 which is attached to the housing 60 at an upper part thereof. Conveniently the upper tether 70 may include an aperture 72. When installing the housing in the vehicle, the upper tether 70 can be slide into the containment pocket 12 until the aperture 72 of the tether 70 receives the tang 14. The tang 14 then acting on the aperture 72 will retain the tether 70 in place prior to inflation of the bolster and during and after inflation as well.

[0015] The inflatable bolster 50, includes a lower tether 80. The lower tether 80 is attached to the housing 60 at a lowermost portion thereof. [0016] The structure indicated above is applicable to the bolster 50 shown in Figures 1A and 1B, the bolster 150 shown in Figures 2A and 2B and the bolster 250 shown in Figures 3A and 3B.

[0017] With respect to Figures 1A and 1 B, the attachment point 18 of the vehicle structure 10 includes a receiver port 90. The lower tether 80 includes a tail 81 , including a barb 82. The tail 81 may be closely, preferably frictionally received, by the port 90.

[0018] In order to install the bolster 50 in the vehicle, the upper tether

70 is pushed into the attachment pocket 12 as explained above. The lower tether 80 is directed through the port 90 with the tines of the barb being collapsed upon passage through the port 90. Because the port 90 receives the tail 81 of the lower tether 80 frictionally, the tether 80 is retained in position as shown in Figure 1A and cannot be easily moved from the configuration shown. [0019] The inflatable bolster 50 includes inflation means which are not illustrated. Generally, the inflation means will include a source of inflating gas, typical of those used in vehicle air bags. This will be connected to an activation source. Advantageously, the bolster 50 may be manufactured in a plastic blow molding operation. The blow molding operation is particularly convenient for making closed, hollow articles. The device may be made with a closed internal chamber 51 which is defined between the aft wall 62, the forward wall 64, the upper side wall 66 and a lower side wall 53. If the chamber 51 is a closed chamber, then that chamber may confine the expanding gas upon activation without the need for an internal bladder. Optionally, the inflatable bolster 50 can include an internal bladder, in which case the chamber 51 need not be a gas tight. If a bladder is provided, then preferably the forward wall 64 will include access means to position the appropriate bladder within the chamber 51 and means for supplying the pressurized gas to the bladder upon activation. [0020] With respect to Figure 1B, the location of the device is shown after complete inflation of the bolster 50. [0021] Upon activation of the bolster, pressurized gas enters the chamber 51. As pressure is increased on the forward wall 54, the forward wall 54 is supported by the vehicle structure 10 so that the forward wall 54 cannot move in the vehicle forward direction relative to the vehicle support structure 10. Thus, all inflating gas pressure, causes relative movement of the aft wall 62 in the vehicle rearward direction relative to the forward wall 64 and relative to the vehicle structure 10. This moves the aft wall 62 in a rearward direction toward the vehicle occupant. Upon inflation of the chamber 51 , the side walls and the upper side wall 66 will unfold with the pleats 68 unfolding and allowing the rearward expansion of the upper side wall 66. Expansion of the upper side wall 66 providing a now substantially horizontal and rearwardly directed upper side wall 66 and the similar lateral side walls, at least a portion of which are also folded, facilitates the rearward movement of the aft wall 62.

[0022] Upon movement of the aft wall 62, the lower tether 80 is pulled from the port 90. The frictional engagement between port 90 and the tail 81 is not sufficient to resist movement under the forces generated during deployment. Thus, the lower tether 80 is free to move until the barb 82 engages the port 90 in the limiting position as shown in Figure 1B. The movement of the lower tether 80 relative to the vehicle structure 10 is referred to in the claims and this disclosure as being extensible. In contrast, the upper tether 70 is substantially inextensible and does not permit any substantial rearward movement of the upper tether 70 during deployment. The effect of the inextensible upper tether 70 anchoring the forward limit of the upper side wall 66 and the extensible movement of the lower tether 80, effectively move the desired impact area on the aft wall 62 not only in the rearwardly direction, but also in the upwardly direction. By reference to Figures 1A and 1B, it will be noted that the design area of impact is given by the arrow A. By reference to the inflated condition shown in Figure 1B, it will be noted that the desired impact area on the aft wall 62 has been moved not only rearwardly but also upwardly to the desired region of impact. The desired area of impact, would be for the 50^th percentile occupant. The substantially vertical extent indicated by the length B shown in Figure 1 B, illustrates the range of acceptable points of impact for occupants on either side of the 50^th percentile size, giving a relatively wide range of acceptable positioning.

[0023] In reference to this structure, it will be noted that the design impact area has been moved rearwardly and upwardly thereby minimizing the likelihood of out of position injuries which might otherwise occur. Also by reference to the figures, it will be noted, that the rearward and upward deployment helps to push the knees up instead of down, thereby reducing the probability of higher femur and tibia axial loads. The bolster helps to cover a larger area of the knee bolster on top, thus keeping the knees from contacting the instrument panel and also helps to prevent submarining.

[0024] By reference to the cross-section of the inflated size of the chamber 51 , it will be noted that there is a smaller volume as compared to the volume that would be required if the chamber did not move both rearwardly and upwardly, given the desired location of aft wall 62 upon completion of inflation. This means that a lower output inflator can be used. It will also mean that because most of the reaction is at the upper portion, a reduced size reaction plate of lower mass may be sufficient to provide the appropriate reaction forces. This follows because most of the reaction occurs at the region just forward of the inflated position of chamber 51 as shown in Figure 1B. [0025] By using attachment points at the top and bottom, the device may be attached to vehicle structure without using any center type of attachment. This can be particularly advantageous where snap fit attachments as outlined above, are utilized. This can help to eliminate the need for riveting or other such attachment of the forward wall relative to the backing plate with consequent savings.

[0026] The bolster 150 illustrated in Figures 2A and 2B is substantially similar to the bolster 50 illustrated in Figures 1A and 1B. The same numbers have been used for components which are otherwise similar.

[0027] In the embodiment illustrated in Figures 2A and 2B, the lower tether 180 interacts with the vehicle structure 10 in a slightly different fashion. In the embodiment illustrated in Figures 2A and 2B, the tail 181 of the lower tether 180 is received in a sliding joint 183. As shown in Figure 2B, the sliding joint 183 allows the tail 181 of the lower tether 180 to move vertically upwardly relative to its initial location on vehicle structure 10. This effectively provides extensible movement of the lower tether 180 so that the aft wall 62, in this embodiment, can move in substantially the same manner as outlined above with respect to Figures 1A and 1B.

[0028] Turning now to Figures 3A and 3B, there is illustrated therein, an inflatable bolster 250. Inflatable bolster 250 is similar to inflatable bolsters 50 and 150 and similar numbers have been used for similar parts.

[0029] In this embodiment of the invention, the lower tether 280 includes a tail portion 281. The tail portion 281 may be permanently affixed to the vehicle structure 10 by a shaft 285. The shaft 285 conveniently passes through the vehicle structure 10, the tail 281 of the lower tether 280 and a mounting flange 286. The shaft 285 may be the shaft of a fastener such as a bolt or rivet or could include a barbed plastic member or other type of retainer. In this embodiment, the tail 281 of the lower tether 280 includes a plurality of folded sections 287. The folded sections 287 may be folded in behind the mounting flange 286 when in the ready position as shown in Figure 3A. Upon deployment of the bolster 250 to the deployed position as shown in Figure 3B, the lower tether 280 becomes extensible in the sense that the folded sections 287 may unfold to provide the same freedom for the aft wall 62 to move to the relatively upwardly and rearwardly location shown in the deployed condition and as discussed above in connection with the embodiments of Figures 1A

[0030] In all of the embodiments discussed above, the effective position of the rear wall 62, or more importantly, the desired impact portion thereof, is upwardly and rearwardly when in the deployed condition as compared to its location in the ready configuration. In these examples, this is achieved by use of a relatively inextensible upper tether and an extensible lower tether. The extensible lower tether allows the rearward and upward movement. The rearward movement to the desired position of the impact portion of the aft wall 62 is advantageously facilitated by use of a folded upper side wall 66. The bolsters 50, 150 and 250 need not necessarily employ a folded upper side wall. If no folded upper side wall is utilized then the uppermost portion of the rear wall 62 would deform to become an upper, rearwardly extending wall because the upper tether 70 is relatively inextensible.

[0031] While the invention has been explained in the context of a knee bolster which may desirably move upwardly and rearwardly, the invention is not limited to a knee bolster nor to a bolster which moves rearwardly or upwardly. The invention is applicable to inflatable bolsters generally and could include, by way of example, door bolsters or head protection curtains and the like. In each case, the bolster is tethered by a first and a second tether, one of which may be extensible and one of which may be less extensible or inextensible, so that a bolster may move in directions as desired. [0032] Various other modification and amendments may be made which are to be considered to be within the scope and spirit of the invention as defined by the appended claims.

Claims

Claims:

1. An inflatable bolster for a vehicle, said bolster comprising:

a housing, the housing defining an internal chamber, an upper tether attached to an upper portion of said housing, a lower tether attached to a lower portion of said housing, wherein said lower tether is extensible so that upon inflation of said chamber, said chamber moves upwardly and rearwardly relatively to said upper tether.

2. The bolster of claim 1 wherein said upper tether is substantially inextensible.

3. The bolster of claim 2 wherein said housing comprises a closed chamber.

4. The bolster of claim 3 wherein said closed chamber includes inflation means.

5. The bolster of claim 2 wherein said housing includes an aft wall, a forward wall and an upper side wall and said chamber is located between said forward wall, said aft wall and said upper side wall.

6. The bolster of claim 5 wherein said upper side wall includes a plurality of pleats.

7. The bolster of claim 6 wherein said lower tether includes a tail portion.

8. The bolster of claim 7 wherein said tail portion of said lower tether is attached to said vehicle for extensible movement.

9. The bolster of claim 8 in which said tail portion of said lower tether is received within a vehicle structure in a sliding friction fit.

10. The bolster of claim 8 in which the tail portion of said lower tether is received in vehicle support structure in an upwardly sliding fit.

11. The bolster of claim 8 wherein the tail portion of said lower tether includes a plurality of folded sections.

12. The bolster of claim 11 wherein said tail portion is fastened to said vehicle structure.

13. The bolster of claim 7 wherein said upper tether includes an aperture and said vehicle includes a retaining tang for interacting with said aperture of said upper tether for retaining said upper tether relative to said vehicle.