APPARATUS FOR BACKWARD DRAWING-IN OF SAFETY BELT STRAP Russian patent published in 2002 - IPC

FIELD: passenger and driver safety equipment used in cars. SUBSTANCE: apparatus has inertia coil with U-shaped casing, shaft mounted inside casing and equipped with spool for winding and unwinding of safety belt strap, spiral spring for rotating shaft in safety belt strap winding direction, coupling adapted for induced backward rotation of shaft and containing drum fixed on shaft and separator fixed on housing. Flexible tie-rod formed as cable is laid in looped state inside separator in spaced relation about drum. One portion of cable is positioned outside and passed through separator brake cams and other opposite end is passed through guiding channel into pyrotechnic device. In case of emergency starting of pyrotechnic device, reverse rotation of shaft and stretching of cable are provided by coupling. Apparatus is further provided with inertia sensitive ratchet mechanism for blocking shaft at accelerated advancement of safety belt strap. Ratchet mechanism has toothed ratchet gear fixed to housing and mounted on shaft end, locking member engageable with ratchet gear teeth and adapted for blocking shaft under load, as well as inertia disk, vehicle state sensor and sensor spring, which are cooperating with locking member for holding it in neutral position, when shaft angular acceleration does not exceed predetermined values. Coupling separator is formed as annular box with alternatively arranged sides surrounding cable loops. Brake cams are arranged on peripheral cylindrical surface of annular box. One of brake cams is offset with respect to others in direction parallel to spool shaft axis. EFFECT: simplified construction and enhanced reliability in operation. 8 cl, 11 dwg