Abstract: A method forms a concave constituting a ball return passage directly on an inner circumferential surface of a nut blank by plastic working without damaging a die. Letter S shaped concaves are formed on an inner circumferential surface of a nut blank, by pressing by use of a die having a blank holder, a cam driver, cam sliders, and a cylindrical member. The cam driver has inclined surfaces having the same angle of inclination as the cam sliders. The cam sliders have letter S shaped convexes corresponding to the letter S shaped concaves, and are held by through holes, respectively. When the cam driver is pressed from the top thereof, the cam sliders move outwardly in the radial direction, respectively, and the letter S shaped convexes push the inner circumferential surface of the nut blank for plastic deformation.

Abstract: A method forms a concave constituting a ball return passage directly on an inner circumferential surface of a nut blank by plastic working without damaging a die. Letter S shaped concaves are formed on an inner circumferential surface of a nut blank, by pressing by use of a die having a blank holder, a cam driver, cam sliders, and a cylindrical member. The cam driver has inclined surfaces having the same angle of inclination as the cam sliders. The cam sliders have letter S shaped convexes corresponding to the letter S shaped concaves, and are held by through holes, respectively. When the cam driver is pressed from the top thereof, the cam sliders move outwardly in the radial direction, respectively, and the letter S shaped convexes push the inner circumferential surface of the nut blank for plastic deformation.

Abstract: Since centers of a second gear, a fourth gear and a sixth gear coincide with each other and are disposed rotatably round a circumference of the same long shaft, a compact configuration can be realized while using a gear train of five gears to obtain a reduction gear ratio of a high gear ratio. The configuration in which the three gears have the same rotational center shaft in the way described above in an actuator which incorporates a plurality of gears is advantageous in that the number of center shafts is reduced and that the number of supporting holes in a housing which support center shafts is reduced.

Abstract: Since centers of a second gear, a fourth gear and a sixth gear coincide with each other and are disposed rotatably round a circumference of the same long shaft, a compact configuration can be realized while using a gear train of five gears to obtain a reduction gear ratio of a high gear ratio. The configuration in which the three gears have the same rotational center shaft in the way described above in an actuator which incorporates a plurality of gears is advantageous in that the number of center shafts is reduced and that the number of supporting holes in a housing which support center shafts is reduced.

Abstract: A seat belt retractor is provided with a pretensioner which comprises a wound-wire tightening mechanism and a drive means. The wound-wire tightening mechanism is composed of a pulley fixedly mounted on an end portion of a take-up spindle and a wire wound around the pulley with a small space left therebetween. The drive means comprises a piston connected to a free end of the wire, a cylinder with the piston movably received therein, a compression coil spring disposed in the cylinder to bias the piston in the pulling direction of the wire, and a trigger unit releasably holding the piston relative to the cylinder such that the piston can be maintained at a biased position against the resilient force of the compression coil spring but the holding of the piston at the biased position can be released responsive to an acceleration of at least a predetermined value.

Abstract: A limit switch unit suitable for use in a passive seat belt system of the type that a movable anchor with a webbing connected thereto is moved by a drive member such as a drive wire along a rail between an occupant-restraining position and an occupant-releasing position. The limit switch unit is composed of a guide for introducing the drive member into the rail and a limit switch for detecting the arrival of the movable anchor at the occupant-restraining position or the occupant-releasing position. The limit switch is integral with the guide, whereby the limit switch unit is formed. A passive seat belt system with the limit switch unit incorporated therein is also disclosed.

Abstract: A passive seat belt system for a vehicle is disclosed. The system includes a guide rail, a slider, a device for adjusting the restraining position of the slider, a trim covering a rear end portion of the guide rail and the adjusting device, and an openable/closable door formed in the trim at a position corresponding to the position of the adjusting device. The slider carries an occupant-restraining webbing, and is arranged movably along the guide rail between the occupant restraining position and an occupant releasing position. The restraining and releasing positions are on the side of the rear end portion of the guide rail and on the side of a front end portion of the guide rail, respectively. The rear end portion of the guide rail extends vertically along a center pillar of the vehicle. The adjusting device is provided on the side of the rear end portion of the guide rail for adjusting the restraining position of said slider.

Abstract: A retractor has a webbing take-up shaft rotatably supported by a base, biasing device for biasing the take-up shaft in a webbing take-up direction, a connecting member for connecting one part and another part of the biasing device, a locking member capable of assuming a locking position engaging the connecting member and a non-locking position disengaging from the connecting member, and a control device for controlling the locking member. When the locking member assumes the locking position, the biasing force of the other part of the biasing device is prevented from acting on the take-up shaft, and when the locking member assumes the non-locking position, the biasing forces of both parts of the biasing device are permitted to act on the take-up shaft.