Patent Application
20130341975
The invention relates to an airbag arrangement for the protection of seat occupants in a vehicle with seats arranged in tandem, so that at least one seat is located behind another.
Airbags have been credited for saving lives by damping the impact of a vehicle crash on a vehicle occupant. Not only frontal impact airbags are in use, but also side impact airbags, such as side curtain airbags expanding from the roof line of a vehicle or airbags arranged in seats, a center console, or an armrest between two car seats. After the gas generator is triggered, the airbag unfolds and provides energy absorption for the seat occupant. An airbag arranged in an armrest pushes itself between the seats and between seat occupants sitting next to each other. Another known airbag design provides an airbag in the vicinity of the center tunnel of the vehicle that inflates above the heads of the vehicle occupants to protect the occupants in the event of a vehicle rollover or of an “off-side” impact.
Airbags are designed to provide a synergetic effect with seat belts that restrain seat occupants in a defined position. At least the front seats of passenger or motor vehicle and increasingly also the rear seats are provided with three-point seatbelts comprising a lap belt and a shoulder harness extending diagonally across a seat occupant's chest. The shoulder harness limits the forward excursion of a seat occupant's upper body in the event of a frontal impact.
In contrast, aircraft passenger seats are usually only equipped with a two-point seatbelt, which is a lap belt without shoulder harness. In the event of a high deceleration of an aircraft, for instance during an emergency landing or a collision, the torso of a passenger is catapulted forward absent a shoulder harness. This constitutes a potentially dangerous situation, where a forward movement may result in high head accelerations and possibly head injuries from a seat back of a seat located in front of the seat occupant.
The object of the present invention is to provide an apparatus that improves the safety of aircraft seat occupants in the event of a high longitudinal deceleration.
According to the present invention, this object is achieved in tandem arrangements with a front seat and a rear seat for a seat occupant of the rear seat by an airbag arrangement on a rear surface of a seat back of the front seat. The front seat of the tandem arrangement may be the rear seat of a different tandem arrangement. The airbag inflates in front of the seat occupant in a direction configured to make a contact with the seat occupant's head or chest before the seat occupant contacts the seat back of the front seat during an impact sequence.
In a normal, deflated state, the airbag is stowed in a rolled or folded bundle at a location in the seat back of the front seat. Upon activation of a pyrotechnical gas generator or compressed gas source, the airbag emerges from the seat back through a horizontal tear seam and unfolds in front of the seat occupant. A preferred location on a typical aircraft seat back is below the hinge of a fold-up table and above a seat pocket of the front seat of the tandem arrangement. When the seat occupant's head and torso, due to inertia, approach the seat back of the front seat, the first contact is made with the airbag by the face or the chest of the seat occupant. Any further forward and downward movement of the seat occupant's head and upper torso is dampened by the inflated airbag that acts like a voluminous pillow. The occupant's head sinks into the airbag and avoids contact with any hard surface, or the severity of such impact can be reduced. The airbag also controls acceleration of the occupant in an effort to reduce related forces to a level below the limits of human tolerance.
The airbag has an inherent shape that expands it upward toward the head of the seat occupant.
Further details and advantages become apparent from the following description of an embodiment of the invention. The drawings are provided solely for illustrative purposes and are not intended to limit the invention to the details shown.
In the drawings,
The seat back 60 of the front seat 52 includes an airbag 10 that is inflated toward the seat occupant 64 during a deceleration event before the head 66 has engaged the seat back 60. Accordingly, the head 66 contacts the inflated airbag 10 instead of continuing to move downward. The head 66 and the upper torso 68 retain an angle between each other that reduces the risk of neck injuries compared to a situation with a bare seat back 60. In the embodiment of
In a second embodiment according to
a and 3b illustrate an example of a physical arrangement of the airbag 10 of
The airbag subassembly 30 comprises the airbag 10, an airbag wrapper 12, a mounting bracket 18, and a gas generator 20. While a pyrotechnical gas generator is depicted in the drawings, the term gas generator is intended to include any device suitable for inflating the airbag. The airbag 10 is in a compacted state, in which it is rolled up about a horizontal axis Y (see
The mounting bracket 18 has a profile shaped like an inverted L in the shown vertical cross-section. It flanks the top of the gas generator 20 and the side of the gas generator remote from the seat occupant 64. A subassembly fastener 24 secures the gas generator 20 along with the wrapper 12 and the airbag 10 to the mounting bracket 18. In the shown embodiment, two of threaded bolts extend from the gas generator 20 and are fastened with corresponding threaded nuts.
If the gas generator 20 is triggered and inflates the airbag 10, the resulting force exerted by the airbag 10 on the wrapper 12 and on the seat cover 14 tears the perforation 22 of the wrapper 12 and the tear seam 16 of the seat cover 14 as shown in
In one embodiment, the airbag 10 may have an inherent shape that causes it to extend upward along the surface 70 rather than toward the seat occupant 64. The airbag 10 is assembled from a top panel 26 and a bottom panel 28. The top panel 26 and the bottom panel 28 are named after their position in the area where the airbag 10 exits the seat back 60. The top panel 26 may, for example be a planar piece of airbag fabric, while the bottom panel 28 may be made from a piece of airbag fabric that is larger than the top panel 26, at least in the direction perpendicular to the axis Y. In order to fit the edges of the bottom panel 28 with the edges of the top panel along a connecting seam 32, the bottom panel may have folds 34 or darts reducing the length of the edge of the bottom panel 28. Due to the greater length of the bottom panel, the airbag inflates into a bent cross-section as illustrated in
The rolled airbag 10 and the gas generator 20 are wrapped into the wrapper 12 that extends around at least a portion of the width of airbag 10. The airbag 10, the wrapper 12, and the gas generator 20 form the subassembly 30 that is preassembled before installation in the seat back 60. In
The L-shaped profile shown in
The seat pocket 58 is arranged below the tray table 56. Between the tray table 56 and the seat pocket 58 extends a gap where the seat cover 14 is visible. the tear seam 16 extends laterally across the gap. Behind the tear seam 16, the airbag subassembly 30 is mounted inside the seat back 60 in a position where the perforation 22 of the wrapper extends in close vicinity of the tear seam 16. The rail 36 of the mounting bracket 18 connects the two vertical struts of the seat frame 72. The tabs 38 and 42 are secured to the seat frame 72 with the same frame fasteners 76 that secure the hinge arms 74. The frame fasteners 76 may be threaded bolts and nuts or other suitable fasteners.
The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
