GB2310408A - Inflatable safety belt for vehicles - Google Patents

Abstract

The inflatable safety belt is manufactured from flat hose that can be automatically inflated when a vehicle is involved in a collision in a similar way to an air bag. The material of the belt stretches circumferentially but not longitudinally during inflation. The belt would be fed from a supply of air or gas from a source of suitable size, eg a cylinder under the seat, and inflate the belt when the air supply was activated. Activation being accomplished by a sensor located in such a position as to be sensitive to a collision but sufficiently insensitive so as not to be activated during severe braking. Alternatively, inflation may be via a valve actuated by the inertia reel of the belt. The belt may be partly inflatable manually to make the belt more comfortable. The belt may be lap only or full harness or a conventional belt may be retro-fitted with inflatable hose. The belt may comprise a number of air tubes to spread the load. The inflating gas may be non-inflammable. A similar system of sensing and inflation to that of an air bag would be used. After inflation the vehicle safety device would provide a cushioned support for the occupant of the seat until the air supply is exhausted or the belt is released normally.

Description

VEHICLE SAFETY DEVICE This invention relates to a vehicle safety device.

Safety belts have become commonplace in all moving vehicles and have had a substantial effect in reducing the injuries sustained during a collision. Since 1965, the law has required all new motor vehicles to be fitted with front seat belts and since 1983 it has been an offence not to wear them.

In 1986 the law requiring rear seat belts to be fitted to all new cars reached the statute book and 1991 Motor Vehicles (Wearing of Seat Belts in Rear Seats by Adults) Regulations make it an offence for adults not to wear seat belts in the back of a car as well as in the front.

Further developments recently in car safety have seen the introduction of air bags, usually fitted in the hub of the drivers steering wheel. These are activated upon collision and provide an inflated bag of air which cushions the drivers head and shoulders reducing the damage on impact with the steering wheel.

Passenger side air bags are also fitted to some vehicles but as yet no further protection is afforded to rear seat passengers.

This invention relates to a new concept of safety whereby the seat belt or part thereof is made from a flat form of hose pipe sealed at both ends and under normal driving works the same as a normal safety belt but at the point of collision, the air supply is activated in the same way as an air bag and the belt itself inflates, thereby providing the air cushion around the front of the wearer.

The clear advantages are that: 1) The vehicle safety device, an inflatable safety belt can be fitted to all seats in a vehicle including the passenger seats of coaches and mini-buses and the rear seats of cars - i.e. in place of a standard seat belt.

2) The vehicle safety device can be fitted in place of lap belts, lap and diagonal belts and full harness type seat belts.

3) Personal injury from the seat belt in the event of collision is reduced since the belt becomes an air filled almost cylindrical cushion immediately after impact.

4) The vehicle safety device is a safety feature in addition to the seat belt and can be used instead of or in addition to an air bag but realistically would replace the air bag in most cases.

5) The vehicle safety device would not cause a dangerous situation to occur if the sensor activated in error, unlike the conventional air bag.

Inflation ofthe vehicle safety device, the inflatable safety belt would be accomplished by a compressed air supply activated by a sensor located in the front of the vehicle designed to be activated on collision. This would be of similar design to the present sensors used to activate air bags and be of such sensitivity as not to be activated during severe braking. An alternative to the sensor could be a valve activated by the inertia reel of the belt itself.

The air supply for inflation would be fed from the supply cylinder or cartridge containing compressed air via a rigid or semi-rigid pipe to the end of each belt nearest to the anchorage point - usually on the floor of the vehicle. Connection into the inflatable section to be a secure integral part of the construction. This would enable the feed pipes to be routed in floor channels and be out of harms way during normal day to day operation of the vehicle.

The supply of compressed air for inflation would be contained in a suitable pressure vessel and be specified in the appropriate regulations covering the transport of compressed gases. The size of such a container would depend on the number of vehicle safety devices that it would be feeding.

The vehicle safety device, the inflatable safety belt would comprise a hose pipe similar in construction to a firefighters hose; that is flat when not inflated and is attached at the anchorage point end to a length of belt with a fastening similar to a conventional seat belt. The length of the non-inflatable section to be sufficient to allow satisfactory securing of the belt in the normal manner. This part may be a glued section of the hose incapable of inflation.

In the more common lap and diagonal arrangement, the inflatable section would start from the belt attached at the anchorage point (normally located on the floor and to the right of the driver in the case of a British car drivers seat belt) proceed across the lap of the person seated and through a slot in the catch bolt and extend to a position just above the opposite shoulder.

The remaining belt would be of conventional design passing through the door pillar mounted guide and down into the inertia reel housing. The slots at the catch bolt fastening and the fixed door pillar guide through which the vehicle safety device would freely pass would necessarily be wider than conventional slots so as not to impede air flow during activation.

Indeed, the catch bolt loop should be almost circular to allow unimpeded inflation.

The design of the vehicle safety device, the inflatable safety belt should incorporate a "quick release mechanism" in the form of a dump valve where the wearer could release the air in the belt after the vehicle has come to rest. This would facilitate release of the belt using the conventional release mechanism. This could be operated by either the wearer or personnel from the emergency services when affecting rescue.

A non-return valve could be incorporated in the inflation line so that when fully inflated, pressure would not be lost during the restraining period of the collision.

The material of manufacture of the inflatable section to be such as to remain flexible in the uninflated state at temperatures normally experienced in the vehicle and to be made from or lined with an impermeable material that can maintain the pressure necessary following collision. The breaking strength of the vehicle safety device is to be equal to or greater than the standards in force at any time for conventional safety belts and conform in all ways with such safety standards in whichever country they are to be used.

Claims (11)

1. A vehicle safety device comprising an inflatable safety belt that inflates immediately on impact by a similar system of activation and air supply to an air bag, replacing a conventional lap and diagonal belt in any vehicle where seat belts would normally be used.

2. A vehicle safety device as claimed in Claim 1 but consisting of only a lap belt a short length of inflatable section would be used terminating in another section of conventional belt at the buckle end. This type of safety belt is normally used in passenger aircraft.

3. A vehicle safety device as claimed in Claim 1 but consisting of a full harness seat belt of the type normally found in racing and competition vehicles where again the sections of belt at the front of the wearer would take the form of an inflatable section.

4. A vehicle safety device as claimed in any preceding claim which can be retrofitted to existing safety belts by attachment thereto. The inflatable part of the vehicle safety device being securely fastened to the safety belt on the side in contact with the wearer.

5. A vehicle safety device as claimed in any preceding claim where the inflatable part is made of ribbed or tubular sections thereby providing a number of air channels effectively spreading the load and improving the cushioning effect of the vehicle safety device.

6. A vehicle safety device as claimed in any preceding claim where the material used in the construction of the inflatable section stretches during inflation thereby reducing the need for a larger cross section belt during normal use.

Stretching to be in the circumferential direction and not longitudinally since this would impair safety in restraint at the time of collision.

7. A vehicle safety device as claimed in any preceding claim where the air for inflation is replaced by some other fluid with properties desirable in the circumstances e.g. carbon dioxide or some other non-inflammable gas if fire safety should be enhanced.

8. A vehicle safety device as claimed in any preceding claim where the air or gas for inflation is fed from both ends of the belt thereby speeding the inflation process.

CLAIMS CONTINUED

9. A vehicle safety device as claimed in any preceding claim where the air for inflation is provided by a local cylinder probably located under the seat and activation effected by an electrically operated valve on or close to the cylinder.

The impact sensor would operate an electrical switch activating the valve releasing the gas for inflation. This would provide quicker inflation of the more remote belts where several vehicle safety devices were installed e.g in the body of a coach/aircraft or the rear seats of a car and reduce expensive pipe runs thereby decreasing installation costs.

10. A vehicle safety device as claimed in any preceding claim where some of the air supply could be fed into the belt manually to make the belt more comfortable for normal wearing.

11. A vehicle safety device as claimed in any preceding claim where the sensor is replaced by a valve actuated by the inertia reel of the seat belt itself- i.e. when the seat belt locks following a sudden and acute breaking of the car, the vehicle safety device would automatically inflate.