| 摘要 |
PURPOSE:To prevent tight roll of a seat belt in the event that a spool is suddenly locked, and an excessive tensile force is applied to a webbing, by moving a belt guide drum to move a movable clamp to a fixed clamp and thereby clamping the webbing. CONSTITUTION:A belt guide drum 4 is movable along guide holes 5 formed through both side walls of a retractor housing 1. A movable clamp 9 of a belt clamp mechanism 7 is connected through a toggle link mechanism 12 to a support shaft 4a of the drum 4. When a spool 2 is suddenly locked upon collision of a vehicle, an excessive tensile force is applied to a webbing 3 by inertia movement of a person who uses the belt, and the drum 4 is moved toward the spool 2 against a force of a spring 6 by the tensile force. As a result, the toggle link mechanism 12 is operated to firmly clamp the webbing 3 in cooperation with the belt clamp mechanism 7. Accordingly, tight roll of the webbing 3 on the spool 2 may be securely prevented. |
