Winding attachment for safety belts in vehicles

Abstract

A winding attachment for passenger safety belts in vehicles comprises an automatic takeup roller over which the belt is entrained having a roller shaft and a clutch disc connected to the shaft which is rotatable in one direction to drive the shaft in a direction to cause the roller to retighten the belt. At least one cylinder having a closed end and an opposite opened end has a piston therein which is movable after ignition of a propellant charge which is contained in the cylinder and which generates a propellant gas which moves the piston in the cylinder toward the open end. A tension member has one end connected to the piston and is engaged adjacent its opposite end around the clutch disc so that when the piston is moved by the ignition of the propellant charge, the tension member causes the clutch disc to drive the takeup reel so as to tighten the seat belt. The propellant charge is advantageously arranged either inside the cylinder on one side of the piston or it is carried in the piston itself and discharges between the piston and the closed end of the cylinder. The construction also can include a winding attachment at each side of the takeup roller in the form of pistons movable in cylinders to drive the takeup roll. The piston advantageously includes a heavy material portion which is sized so as to regulate the amount in which it will move out the open end of the cylinder.