Patent ID: 8256699

Claim:
A webbing take-up device, comprising: a take-up shaft that takes up a webbing for restraining a vehicle occupant; a motor; and a speed reduction mechanism that reduces a rotation speed of the motor, transmits rotation to the take-up shaft, and rotates the take-up shaft, the speed reduction mechanism including an overload release mechanism including: a motor-side rotation body that is rotated by rotation of the motor being transmitted thereto at the reduced rotation speed of the motor, a spring member that is fixedly mounted to the motor-side rotation body in such a manner that relative rotation between the spring member and the motor-side rotation body is prevented, and a take-up shaft-side rotation body that is provided to be coaxial and relatively rotatable with respect to the motor-side rotation body, that rotates the take-up shaft by rotation thereof being transmitted to the take-up shaft via at least one gear, that engages with the spring member to prevent relative rotation with respect to the motor-side rotation body when a rotation force less than a predetermined value acts between the motor-side rotation body and the take-up shaft-side rotation body, and that allows relative rotation with respect to the motor-side rotation body by sliding over the spring member when a rotation force greater than or equal to said predetermined value acts between the motor-side rotation body and the take-up shaft-side rotation body.