Abstract:
An inflatable vehicle safety system having a source of inflating gas and an inflatable bag in which a flat, woven hose connects the gas source to the inflatable bag using minimal connecting hardware.

Description:
BACKGROUND OF THE INVENTION 
     In the past various types of protective devices have been used in vehicles to reduce injury to occupants during a crash event. In ground transportation vehicles, the protective devices started with lap belts, moved to lap/shoulder harnesses and then added inflatable systems where the inflatable device is stored in a fixed structure. For example, air bags used in automobiles are commonly stored in the steering wheels, instrument panels, side panels and roof rails. In aircraft, the protective devices started with lap belts and have recently introduced seat belt air bags, which have an inflatable member inside or on the seat belt. When deployed, the aircraft seat belt air bag device inflates an air bag into the area in front of the occupant wearing the seat belt. All air bag systems use a crash sensor that identifies a crash event and then activates a gas supply source. The most common automotive driver and passenger air bag systems have the gas source and bag storage co-located in the steering wheel or in the instrument panel. A gas delivery hose of substantially non-flexible construction is used when the gas storage is remote to the air bag storage such as in the aircraft air bag system. 
     The most common automotive driver and passenger air bag systems require redesigning the steering wheel or the passenger side instrument panel to install the air bag device. In ground vehicles, a seat belt air bag system does not require as much component redesign to install as they replace the seat belt and have the gas source mounted under the seat. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an inflatable bag vehicle safety system which can be conveniently installed in vehicles or aircraft. The system components are light and flexible and require minimal intrusion into driver/passenger space. Cost and installation times are minimized by virtue of the design simplicity of the system, particularly by reducing the number of hard fittings required. 
     A further improvement is the provision of a gas escape passage where the inflating gas is introduced into the inflatable bag, which escape passage can be accurately sized to control the rate of gas escape bag deflation after a crash event. 
     The present safety system utilizes a source of pressurized gas which is released to inflate a protective bag. The bag is contained within a suitable protective cover and is located on the lap belt portion of a restraining harness. The restraining harness can be either of the two or three point variety, as desired. A three point restraining system utilizes a shoulder strap whereas a two point system uses only a lap belt, all as well known in the art. When gas is released in response to sensing devices, it flows from the source of gas to the inflatable bag through a flat seamless flexible woven gas supply hose. This hose can be a polyester weave containing strands of kevlar for strengthening and can be coated internally with polyurethane. The use of this flat yet flexible hose saves space and also imparts a suppleness that enhances the user&#39;s comfort, as compared to the round gas metal supply tubes used in prior art systems. 
     The inlet end of the supply hose is connected to the gas source by a standard plastic or metal fitting but the outlet end of the hose which is located in the inflatable safety bag has no fitting whatsoever. Specifically, the outlet end of the hose is positioned within the inflatable bag and secured to the bag but not to the underlying lap belt part. The lap belt part is in the preferred embodiment secured to the bag at a location other than where the hose is attached to the bag. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic side elevation of the present safety system, as used with a  3 -point safety belt; 
     FIG. 2 is a front elevation of the system of FIG. 1 with the safety belt in stored position; 
     FIG. 3 is a view like FIG. 2 with the belt in the operative position; 
     FIG. 4 is a top plan view with parts broken away, showing the hose entry into the bag; 
     FIG. 5 is a view taken along the line  5 — 5  of FIG. 4; 
     FIG. 6 is a portion of the inflatable bag removed, showing the connections between the supply hose and the inflatable bag and safety belt; 
     FIG. 7 is a side elevation of FIG. 6; and 
     FIG. 8 is a diagrammatic view showing that the cross-sectional area of the opening from the bag inflating hose into the inflatable bag is at least as great as the cross-sectional area of the hose. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     For a clearer understanding of the invention, reference is made to the figures of the drawings and first to FIG. 1 wherein the numeral  10  indicates a steering wheel, column  11  and a seat structure  12  of the general type that might be found in a commercial vehicle, such as a delivery van, school bus or the like. Shown in back of seat  12  is a restraint system  15  that is illustrated as being of the three point type. In this type of system, there is a restraining shoulder strap  16  and a lap belt part  17  that extends across the user&#39;s lap when in the restraining position. Also present in the present restraint system is an inflatable bag  20  that is mounted on the belt part  17  in a position causing the bag  20  to occupy a location in the lap of an occupant, when the belt part l 7  is drawn across the occupant&#39;s body. The lap belt part  17  is one of two belt parts that make up the lap portion of the restraining belt, the other lap belt part being that indicated by the numeral  21  which is attached at one end to the vehicle in the same manner as the end  22  of strap  17 . 
     Located beneath seat  12  is a source of inflating gas  25  which can be suspended from the bottom of seat  12  as by brackets  26  or by any other suitable means. Alternatively, the gas supply could be located on the floor of the vehicle if the vehicle construction permitted this sort of part disposition. Extending from the source of inflating gas  25  is the flat seamless woven flexible gas supply hose  30  which at a first end is connected to the source of inflating gas  25  by a standard screw fitting or the like. The hose extends upwardly from gas source  25  along side or internal to the strap  17  until it enters the inflatable bag  20 . 
     Referring to FIG. 4, hose  30  can be seen as inserted into the interior of inflatable bag  20  through a cut or slit  32  in the wall of inflatable bag  20 . The opening formed by the slit  32  has inserted into it a fabric collar  33  which is sewn internally in the bag  20  along the stitching lines  34 . An extension  35  formed on collar  33  extends outwardly of the slit  32  from the interior of inflatable bag  20 . On each side of the supply hose  30 , the extension  35  has stitching lines  36  which define the lateral limit of the opening through which supply tube  30  is inserted to the interior of bag  20 . By varying the position of stitch lines  36  with respect to the lateral limits of the flat woven hose  30 , the size of the opening space  37  between the wall of tube  30  when it is inflated and the wall defining the opening through extension  35  can be controlled for passage of either greater or lesser amounts of air after the bag has been inflated. 
     FIG. 5, which is a view taken along the lines  5 — 5  of FIG. 4, shows the overlapping relationship of the collar  33 , the bag  20  and the hose  30  and the opening  37  that limits the release of gas from the inflated bag  20 . 
     FIG. 6 illustrates the manner in which a portion of the second end of hose  30  specifically the end that is located within bag  20 , is attached in position within the bag. First, it should be noted (FIG. 7) that a portion of the end of hose  30  has been removed so that this portion of the end of the hose is only one-half its thickness of the remainder of the hose. This reduction in thickness of the hose permits the fastening structure, specifically the stitching illustrated in FIGS. 6 and 7, to securely fasten the hose  30  to the wall of bag  20 . Alternatively, hose  30  can be sewn to the bag  20  without removal of a portion of the hose wall, but use of the single wall portion is preferred to achieve surety of the fastening. This reduced section of hose which is identified by the numeral  40  in FIG. 7 is held in position by the stitching, fastening structure, i.e. illustrated at  41  which extends only between the reduced portion  40  and the wall of the bag  20 . To the left of the reduced section  40 , there is shown additional stitching  42  which also extends between the hose and the bag but which in this case acts to shut or close the end of the supply tube  30  to prevent the passage of air through the end of the tube. Additional fastening structure (stitching) is identified by the numeral  43  and this stitching extends only between the bag  20  and the lap belt part  17 . From this construction, it can be seen that there is a physical connection between the supply hose and the bag  20  on the one hand, and a connection only between belt  17  and bag  20  on the other. This type of connection between the elements of the safety system are preferred, although it may be possible for other interconnections to be made between these parts. 
     Referring to FIG. 6, is will be seen that the length of hose  30  adjacent to the second end of the inner length of supply hose  30  contained within bag  20  has been formed with a plurality of gas outlet ports  45  to provide for the entry of gas into the bag  20  from the source of inflating gas  25  via the supply tube  30 . It will be appreciated that when the gas supply  25  is activated, the pressure of the gas entering the flat supply tube  20  will cause the tube to become circular in cross section. Although a plurality of openings  40  have been illustrated, other exit hole configurations can be used as well. For example, an elongated opening could replace the plurality of holes, or the end of the tube could be left unclosed. The requirement is that whatever the size of the exit from the supply tube into the bag is the cross sectional area should, for optimal operation, be equal to or greater than the cross sectional area of the inflated tube. For example, as diagrammatically shown in FIG. 8, the cross-sectional area “A” of the unsealed inner end of hose  30  is at least as large (it can be larger, but not significantly smaller) as the cross-sectional area “A”. Cross-sectional A′ represents a section taken at any location along the length of hose  30 . If a plurality of openings are used to transport gas from hose  30  into bag  20 , such as openings  45 , the combined areas of the openings must be at least as great as area A. 
     The invention may be embodied in other specific forms and the form described above is to be preferred but is not intended to be limiting to the scope of the invention described.