Abstract: A steering column safety device for use in a motor vehicle having a steering wheel for communicating steering torque to a steering mechanism, and having a collision sensing assembly for sensing a collision, includes a hollow cylinder having a top end and a bottom end, the top end being sized and configured for fixed, torque-transmitting connection to a steering wheel; a piston residing within the cylinder for sliding, telescopic reciprocation between an extended position and a collapsed position; an elongated rod with first and second ends, the first end being secured to the piston and the second end being sized and configured for fixed, torque-transmitting connection to the steering mechanism; structure for transmitting torque between the cylinder and the rod; a sealing assembly for sealing the hollow cylinder to define a fluid-tight cavity within the hollow cylinder between the piston and the top end of the cylinder, the fluid-tight cavity containing prior-to-collision pressurized gas; and, a mechanism to r

Abstract: A collapsible steering column for a motor vehicle has an elongated hollow cylinder slidably mounted on a piston while also fast to the piston for rotary movement. The space between the interior wall of the cylinder and the piston is sealed in a gas-tight fashion. A head is attached to the top of the cylinder. The head has a frangible seal hermetically secured inside it so that the top of the piston, the interior wall of the cylinder and the seal define an air cavity. The cavity is under pressure such that the cylinder is supported by a column of pressurized gas. A coil spring inside the cylinder urges the piston and the bottom of the cylinder apart. The seal has a bore in which resides an explosive compound. Lead lines connect the explosive compound with an electronic collision sensor, which is located in the front of the vehicle.