Abstract: An inexpensive webbing retractor is obtained by making a pretensioner and a lock device small and reducing the number of parts. A plurality of protrusions are formed on an inner peripheral portion of the bearing body, which pivotally supports a clutch portion. These protrusions are brought into linear contact with an outer peripheral portion of the clutch portion, whereby the bearing body pivotally supports the clutch portion indirectly via the protrusions. Since the protrusions are brought into linear contact with the clutch portion, the contact area becomes quite small. Hence, the protrusions are easily plastically deformed due to friction resistance with the clutch portion. Therefore, resistance that obstructs the rotation of the clutch portion becomes small, and gas pressure can be efficiently supplied for the rotation of a take-up shaft.

Abstract: A webbing retractor for webbing belt retraction and restraint of a vehicle occupant during sudden deceleration. In a preferred embodiment, the webbing retractor includes a spring, and is for connection to an axially rotatable shaft having a locking device. The locking device includes a rotator coaxially rotatable with the shaft and a locking mechanism. The spring resiliently urges the shaft to retract the webbing belt, which can be ordinarily unwound against the spring tension. During sudden deceleration, the locking mechanism is activated and limits or prevents unwinding of the webbing belt. The retractor includes wall portions provided at the rotator and the shaft, with the spring disposed between these portions. A hole for insertion of the spring is provided between the wall portions. The hole is sized such that the spring must be at least partially compressed for insertion therethrough. The arrangement facilitates insertion of the spring, and stable connection of the spring in the assembly.

Abstract: A webbing sensor for a vehicle safety restraint retractor. The sensor comprises an inertial member, mounted for rotation coaxially with a retractor spool, a pawl for engaging the spool and locking it against rotation under emergency conditions, and a calibration spring biasing the inertial disc so that it tends to rotate with the spool unless there is a sudden acceleration or deceleration of a value such as to overcome the resilience of the spring. The spring is connected to the spool via the pawl so that relative rotation between the disc and the spool results in movement of both ends of the spring, preferably by approximately the same distance. Throughout the locking procedure, the spring force remains substantially constant and thus the bias torque on the inertia disc remains substantially constant, and the locking performance of the sensor is improved.

Abstract: A guide pin is provided erect at a lock plate of a webbing retractor. A guide hole is formed in a V gear in correspondence with the guide pin. The guide hole is formed from a first hole portion, a second hole portion and a third hold portion. A state in which the guide pin is positioned in the first hole portion is an initial state. When relative rotation between the V gear and a spool arises, the guide pin moves from the first hole portion and reaches the second hole portion. In this process, the guide pin pushes the V gear so as to rotate reversely, and locking is cancelled. When a pushing force causing a V gear reverse rotation angle to exceed a set value is applied from the guide pin, the guide pin escapes into the third hole portion such that excessive pushing force is cancelled.

Abstract: In a webbing retractor, when a pawl engages with an internal tooth, a lock plate is guided, via a V gear, to a position at which engagement with a ratchet tooth is possible, and thereafter, the lock plate self-locks. When the V gear reversely rotates by a predetermined amount in accordance with this self-locking, engagement of the pawl and the internal tooth is cancelled. An engagement surface of the internal tooth corresponds to a locus of swinging of the pawl. Engagement with the pawl is cancelled at a smallest V gear reverse rotation angle.

Abstract: At a lock plate of a webbing retractor, a pair of pawls and a connecting shaft are molded integrally such that the lock plate is rotated appropriately such that the connecting shaft of the lock plate is inserted into a spool from a cut-out portion and two operational surfaces oppose respective load receiving surfaces, and thereafter, other parts are assembled.

Abstract: There is provided a webbing take-up device of which weight can be reduced while maintaining lock strength. A single lock plate which is engaged with an internal gear ratchet at the time of sudden deceleration of a vehicle is held in an accommodating portion formed in a holding portion of a base lock. At the time of sudden deceleration of a vehicle, the lock plate is moved by being guided in a guide hole of a V gear and is engaged with the internal gear ratchet. Further, reaction force generated in the above-described engagement is utilized and the holding portion of the base lock is caused to contact by pressure the internal gear ratchet and the base lock plastically deforms and is thereby engaged with the internal gear ratchet. Accordingly, the base lock and the internal gear ratchet are in a locked state at two facing locations on the base lock in a radial direction of the base lock.