Air Bag for a Passenger

The present invention relates to an air bag, which comprises a plurality of base cloths and which protects the person in a vehicle when it is inflated by reaction gas from an inflator during a collusion of the vehicle, and in particular to an air bag for passengers in seats other than the driver's seat.

The air bag unit, provided on a fixed portion of car body in front of the seat in a vehicle, plays an important role for protecting the passengers in the vehicle from injury due to collision against the car body. The air bag is inflated instantaneously by pressure of a reaction gas released a) from an inflator fixed on the steering wheel for a driver or b) from an inflator fixed on an instrument panel or other fixed portions of a car body for a passenger in case of an emergency such as the collision of the vehicle.

In an air bag unit for a passenger in the assistant seat, as shown in FIG. 6, the gas generating agent in the inflator 2 induces a chemical reaction by a collision signal from a collision detecting sensor (not shown) when the deceleration of the vehicle exceeds a certain level. The air bag 3 is instantaneously inflated and expanded by the generated reaction gas. Then, the air bag 3 receives the person M, who is thrown forward by inertia and protects the person M from collision against the car body.

A large space is present between the assistant seat and instrument panel or front windshield. Moreover, such a large space is often asymmetrical from the left and right of the car body, and such an asymmetrical shape differs widely according to each car model. In this respect, the conventional type air bag 3 for a passenger is formed in a complicated shape as shown in FIG. 7 in order to effectively protect the passenger by properly fitting the shape of such a large space.

When the air bag 3 takes such a complicated shape, the sewn shape when base cloths 3a and 3b are sewn up becomes also complicated as shown in FIG. 7, and it is not possible to automatically sew up the air bag 3 by machine. As a result, the conventional type air bag 3 for a passenger is manually sewn.

The same problem exists with the air bags for the passengers in the back seats, although these are not shown in the figures.

Manual sewing of these base cloths 3a and 3b results in intricate sewing for the air bag 3, and a lot of time is required for producing the air bag 3. Because the base cloths of complicated shape are sewn up, the convention type air bag for passengers does not flexibly fit a wide variety of asymmetrical shapes, which differ according to each car model. As the result, there have been problems with the conventional type of air bag for passengers, such as low productivity or high manufacturing cost.

It is an object of the present invention to offer an air bag for a passenger, which can automatically be sewn up by machine at least partially.

Another object of the invention is to offer an air bag for a passenger, which can flexibly and easily match various asymmetrical shapes in both vertical and lateral directions.

To attain such objects, the air bag for a passenger according to the present invention comprises a plurality of base cloths, and it is characterized in that at least a part of a plurality of base cloths can be automatically sewn up by machine.

In this case, the shapes automatically sewable by machine include: circular, elliptical or oval shape or a shape similar to such a circular shape, and polygonal shape or polygonal shape with rounded corners.

The air bag for the passenger according to the present invention comprises an inflator or an air bag base fixed on a fixed portion of a car body and a passenger receiving unit to receive the passenger, and it is characterized in that the passenger receiving unit is sewn to the air bag base.

In this case, at least a part of a plurality of base cloths can be automatically sewn up by machine.

In the air bag for the passenger according to the present invention with such an arrangement, at least a part of a plurality of base cloths can be automatically sewn up by machine. Therefore, sewing is performed easier, and the time required for the manufacture of the air bag for the passenger can be reduced.

In the air bag for the passenger according to this invention, the air bag base can be connected to any desired position of the passenger receiving unit. Accordingly, it is possible to form the air bag for passengers in order to flexibly and easily match various asymmetrical shapes in both vertical and lateral directions.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

FIG. 1 is a perspective view showing an embodiment of an air bag for a passenger according to the present invention;

FIGS. 2(a) and (b) and FIG. 3 show base cloths to be used in the embodiment;

FIGS. 4(a)-(e) represent other embodiments of the invention;

FIGS. 5(a)-(d) show still other embodiments of the invention;

FIG. 6 is a schematical cross-sectional view of an example where the air bag unit for a passenger is mounted on an instrument panel and when the air bag is inflated.

FIG. 7 shows an example of a conventional type of air bag for a passenger.

An air bag unit 1 is shown in FIG. 1. In the figures, the same component is referred to by the same reference symbols, and a detailed description is not given here.

As shown in FIG. 1, the air bag 3 for a passenger comprises a passenger receiving unit 3c mounted face-to-face to the passenger and used for receiving the passenger and an air bag base 3d fixed on an inflator or on a fixed portion of a car body.

The passenger receiving unit 3c consists of a base cloth 3c.sub.1 facing toward the passenger and a base cloth 3c.sub.2, to which the air bag base 3d is connected. As shown in FIGS. 2(a)-2(b), these base cloths 3c.sub.1 and 3c.sub.2 are cut in a circular shape of the same size. The base cloth 3c.sub.2 is provided with a circular hole 3c.sub.3, through which reaction gas from the inflator flows. By sewing (.alpha.) the outer periphery of the base cloth 3c.sub.2 on the air bag base 3d with the base cloth 3c.sub.1 on the passenger side, the passenger receiving unit 3c is provided in the form of a bag.

As shown in FIG. 3, the base cloth 3d.sub.1 of the air bag base 3d is formed in the shape of a sector. By sewing (B) both ends 3d.sub.2 and 3d.sub.3 of the base cloth 3d.sub.1, the air bag base 3d, in the shape of a truncated cone, is formed.

To form such an air bag 3 for a passenger, the air bag base 3d in the shape of the truncated cone is formed by sewing (.beta.) both ends 3d.sub.2 and 3d.sub.3 of the base cloth 3d.sub.1 manually. In this case, the sewing (B) of both ends 3d.sub.2 and 3d.sub.3 of the base cloth 3d.sub.1 is performed manually, while this can be done in a relatively short time because it is straight sewing. Next, the outer periphery 3d.sub.4 of the air bag base 3d and the inner periphery of circular hole 3c.sub.3 of base cloth 3c.sub.2 are sewn up (.gamma.) after basting or heat-sealing. In this case, because the outer periphery 3d.sub.4 of the air bag base 3d and the inner periphery of the circular hole 3c.sub.3 of the base cloth 3c.sub.2 are in a circular shape, the air bag base 3d and the base cloth 3c.sub.2 are sewn up (.gamma.) in a circular shape, and this sewing process can be automatically performed by machine. Accordingly, the sewing (.gamma.) of an air bag base 3d with base cloth 3c.sub.2 can be done in an extremely short time. Finally, after base cloths 3c.sub.1 and 3c.sub.2 are combined together, the outer periphery (o) is sewn up. Because the outer periphery of base cloth 3c.sub.1 and that of 3c.sub.2 are in a circular shape, these two base cloths 3c.sub.1 and 3c.sub.2 are sewn (.alpha.) in a circular shape. Thus, automatic sewing by machine can be achieved. Accordingly, the sewing (.alpha.) of these two base cloths 3c.sub.1 and 3c.sub.2 can be done in an extremely short time. As a result, the air bag 3 for a passenger as shown in FIG. 1 is formed.

FIGS. 4(a)-4(e) show other embodiments of the air bag 3 for a passenger as seen from the direction of the arrow A in FIG. 1. The same components as the above embodiment are referred to by the same symbols, and a detailed description is not given here.

In the air bag 3 of FIG. 4(a), the passenger receiving unit 3c is formed in a square shape when seem from the direction A, and a circular hole 3c.sub.3 is furnished nearly at the center. In the air bag 3 of FIG. 4(b), the passenger receiving unit 3c is formed in a square shape with rounded corners (R), and the hole 3c.sub.3 in the shape similar to that of the passenger receiving unit 3c is furnished nearly at the center. Further, FIG. 4(c) shows a passenger receiving unit 3c in a rectangular shape having 4 rounded corners (R) and furnished with a hole 3c.sub.3 in the shape similar to the rectangular shape. FIG. 4(d) shows a passenger receiving unit 3c in a polygonal shape (In the figure, an example in octagonal shape is shown.) and a circular hole 3c.sub.3 FIG. 4(e) shows an air shape and a hole 3c.sub.3 in the shape similar to the ellipse. It is needless to say that various types of air bags 3 can be formed by combining the passenger receiving unit 3c of various shapes with the hole 3c.sub.3 of various shapes.

The air bag 3 thus formed is in such a shape that the sewn portion .alpha. and .beta. can be automatically sewn up by machine. This results in extensive reduction of the time for the manufacture of the air bag 3 and in the improvement of productivity. Thus, the manufacturing cost of air bag can be extensively reduced.

FIGS. 5(a)-5(d) represent other embodiments of the air bag 3 for a passenger similar to the embodiments of FIGS. 4(a)-4(e). The same components in the above embodiments are referred to by the same symbols, and a detailed description is not given here.

As shown in FIGS. 5(a)-5(d), the hole 3c.sub.3 is eccentrically provided to the passenger receiving unit 3c in these embodiments. Accordingly, the air bag base 3b is eccentrically sewn up to the passenger receiving unit 3c. FIG. 5(a) shows a combination of a passenger receiving unit 3c in a circular shape and a circular hole 3c.sub.3 provided eccentrically toward the right in this passenger receiving unit 3c. FIG. 5(b) shows a combination of a passenger receiving unit 3c in a rectangular shape with rounded corners R and a hole 3c.sub.3 in the shape similar to the rectangular shape and furnished eccentrically toward the left in this passenger receiving unit 3c. FIG. 5(c) shows a combination of an elliptical passenger receiving unit 3c and a hole 3c.sub.3 in the shape similar to the ellipse and furnished eccentrically toward the right in this passenger receiving unit 3c. FIG. 5(d) shows a combination of rectangular passenger receiving unit 3 c with rounded corners R and a hole 3c.sub.3 in the shape similar to the rectangle and furnished eccentrically toward the lower left in the passenger receiving unit 3c. It is needless to say that various types of air bags can be formed by properly combining the passenger receiving unit 3c of various shapes with the hole 3c.sub.3 of various shapes as in the case of the above embodiments. Also, the degree of eccentricity of the hole 3c.sub.3 can be set as appropriate.

In this way, by furnishing the hole 3c.sub.3 eccentrically in the passenger receiving unit 3c, it is possible to make the shape of the passenger receiving unit 3c asymmetrical in a lateral direction when seen from the direction A in FIG. 1 and also to easily change the rigidity of the air bag 3 to the center. The space where the air bag for the passenger is installed, e.g. in case of an assistant seat, has a complicated and laterally asymmetrical shape because of the shapes of the front windshield and the instrument panel. The shape of such a space varies widely according to each car model. The air bag can now easily match the space of a diversified shape.

As it is evident from the above description, it is possible according to the air bag for a passenger of this invention to automatically sew up at least a part of a plurality of base cloths of the air bag by machine. This results in easier sewing and extensive reduction of the time required for the manufacture of the air bag for the passenger. As a result, productivity is greatly increased, and the manufacturing cost can be reduced.

It is possible by the air bag for the passenger of this invention to connect the air bag base to the desired position on the passenger receiving unit. Therefore, the air bag for the passenger can flexibly and easily match the various complicated shapes, which are asymmetrical in both vertical and lateral directions.