A webbing winding device includes a spool, a sensor lever, and a solenoid. The sensor lever is displaceable between the first position and the second position. In a state where the sensor lever is disposed at the first position, the rotation in the drawing-out direction of the spool is enabled, and in a state where the sensor lever is disposed at the second position, the rotation in the drawing-out direction of the spool is locked. When the solenoid is actuated, a part of the sensor lever is attracted and the sensor lever is displaced from the first position to the second position. The center of gravity of the sensor lever is set so that the sensor lever is displaced toward the second position when negative acceleration with respect to the direction in which a part of the sensor lever is attracted to the solenoid is generated in the sensor lever.

A seatbelt retractor configured to ease the tightness of a seatbelt felt by an occupant when the occupant wearing the seatbelt reclines a seatback. An acceleration sensor 70 includes a sensor cover 71 which tilts with a seatback, a sensor housing 72 supported swingably with respect to the sensor cover 71 and having an inertial body support surface 78 and an inertial body 73 which is displaced when the acceleration reaches at least a prescribed value. The sensor housing 72 includes an external teeth part 84 having a plurality of external teeth 81 and 82 and a gap part 83 without external teeth. A lever member 90 is coupled to the shaft 22 of the spindle 20 by a friction coupling, and the lever member turns in a first direction in which an engagement part 92 is engaged with the external teeth part 84 when the spindle 20 rotates in a seatbelt drawing-out direction and turns in a second direction in which the engagement part 92 moves apart from the external teeth part 84 when the spindle 20 rotates in a seatbelt winding-up direction.

A vehicle sensor device comprising a weight body housing installed in a body so as to be rotatable around a shaft coupled to the body, a weight body being installed in the weight body housing ball assembly for sensing a change in inclination of a vehicle, a sensor housing in which the ball assembly is movably installed, and a sensor lever installed in the sensor housing and rotated by the movement of the ball assembly. The sensor lever is configured to linearly reciprocate, by rotation, a pilot lever provided in a locking device. The sensor lever is installed in the sensor housing to which the ball assembly is coupled. The sensor lever is rotated around a hinge shaft by the movement of the ball assembly according to a change in inclination of the vehicle to linearly reciprocate the pilot lever connected to the sensor lever.

A seatbelt retractor configured to ease the tightness of a seatbelt felt by an occupant when the occupant wearing the seatbelt reclines a seatback. An acceleration sensor 70 includes a sensor cover 71 which tilts with a seatback, a sensor housing 72 supported swingably with respect to the sensor cover 71 and having an inertial body support surface 78 and an inertial body 73 which is displaced when the acceleration reaches at least a prescribed value. The sensor housing 72 includes an external teeth part 84 having a plurality of external teeth 81 and 82 and a gap part 83 without external teeth. A lever member 90 is coupled to the shaft 22 of the spindle 20 by a friction coupling, and the lever member turns in a first direction in which an engagement part 92 is engaged with the external teeth part 84 when the spindle 20 rotates in a seatbelt drawing-out direction and turns in a second direction in which the engagement part 92 moves apart from the external teeth part 84 when the spindle 20 rotates in a seatbelt winding-up direction.

A webbing winding device includes a spool, a sensor lever, and a solenoid. The sensor lever is displaceable between the first position and the second position. In a state where the sensor lever is disposed at the first position, the rotation in the drawing-out direction of the spool is enabled, and in a state where the sensor lever is disposed at the second position, the rotation in the drawing-out direction of the spool is locked. When the solenoid is actuated, a part of the sensor lever is attracted and the sensor lever is displaced from the first position to the second position. The center of gravity of the sensor lever is set so that the sensor lever is displaced toward the second position when negative acceleration with respect to the direction in which a part of the sensor lever is attracted to the solenoid is generated in the sensor lever.

A seat belt retracting and locking apparatus and an automotive seat including a seat belt retractor, a sensor having a sensing seat and a sensing ball, and a locking mechanism. When the locking mechanism is in a locking state, the sensing seat is fixed in an initial position. When the locking mechanism is in an unlocking state, the sensing seat is rotatable. When the seat belt retracting and locking apparatus and the automotive seat are in a normal state, the sensing seat is locked in the initial position by the locking mechanism, and the angle and the position of the sensing seat are not affected by a change in the speed of a vehicle, so that relative positions between the sensing ball, a pawl, and a ratchet do not change, thereby improving the stability of the performance of the apparatus and seat.