There are so many different kinds of vehicular accidents, and they can broadly be classified single vehicle accidents, or multiple vehicle accidents. Some can cause the chassis and/or the roll cage to deform and make it extremely difficult to open the doors to escape, particularly if the occupants are injured and have to evacuate the vehicle. Some scenarios are high-speed collisions, vehicle roll-overs, dropping of the vehicle from a height, etc. Precious time is lost in waiting for the fire department to cut up the cabin and rescue the occupants. In some cases, giving the occupants a chance to escape by providing the means necessary to do so will be the difference between life and death.
Having explosive bolts in door hinges can provide a means of escape. Since hinges are the single points at which the door is fixed to the vehicle, its destruction means that the door can be ejected or dropped when the bolt is detonated. The explosive must be powerful enough to destroy the hinge, but must be mild and designed so that:
1. flying debris must not enter the cabin,
2. the detonation must not disorient the occupants who may be injured already
3. the door should breakaway cleanly and not leave a jagged or sharp edge that can cause further injury.
A similar application is used in cockpit canopies of fighter jets, used when the pilot has to eject from the aircraft. Like the aircraft, the explosives can be triggered by mechanical means like a button or a lever that is easily accessible, but is only armed when the roll cage is deformed. The force required to deform the roll cage must be calculated, depending its design and material properties. To detect deformations, load cells can be placed in strategic crumple-zones in the chassis, programmed to remain idle while normal forces act on the chassis, such as everyday bending and twisting during the operation of the vehicle. These forces are generally small in comparison to forces that can damage the chassis, and will not arm the device. However, when a large force deforms the chassis, the load cell condition is satisfied and relays a signal electrically to the device which then arms it and awaits the signal to detonate. On actuating the system, the charges within the hinge are detonated, separating the door from the vehicle and providing an escape path for the occupants, or rescue teams that answer the call.
1. The load cells can be installed before upholstery, and must be regularly serviced and adjusted during maintenance.
2. The chassis must be designed such that the installation of the load cells must not compromise its structural integrity.
3. Detonation can also be achieved using a highly compressed gas canister.
4. Designing a ballistic shield that also acoustically shields the occupants is imperative to make this device work.
5. Weight reduction in the apparatus without compromising its function and structural integrity.