Shock-proof device, buckle having the shock proof device, and seatbelt apparatus having the buckle

摘要

A shock-proof device disposed in a buckle includes at least a latch member for engaging a tongue so as to latch the tongue; a release button for releasing the tongue from the latch member; and an inertia lever with a rotation shaft rotatably arranged for preventing the release button from moving at least in a release direction of the release button by abutting against the release button. The shock-proof device further includes torque-difference generating mechanism for generating a torque difference between a first torque and a second torque. The first torque is applied to the inertia lever when the inertial force is applied to the release button and the inertia lever in the release direction of the release button. The second torque is applied to the inertia lever when the inertial force is applied to the release button and the inertia lever in the non-release direction of the release button.