Webbing winding device
AssigneeKabushiki Kaisha Tokai Rika Denki Seisakusho
InventorTakahiro OSAKI
Life of this patent
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Abstract
A difference in limiting torques of rotation between a spring and a rotary member is increased without increasing a number of coils of the spring. In a webbing winding device, an outer diameter of a clutch wall of a clutch wheel increases from a flange side to a stopping flange side of the clutch wall. When a clutch spring is tightly wound on the clutch wall, the clutch spring is subjected to a movement force toward the stopping flange side. Thus, a winding force of the clutch spring onto the clutch wall is effectively increased. Therefore, a difference in limiting torques of rotation between the clutch spring and the clutch wheel between when the clutch spring is not tightly wound on the clutch wall and when it is wound on the clutch wall is increased, without increasing a number of coils of the spring.
Claims7
A webbing winding device comprising:
- a spool that, by being rotated, winds and unwinds a webbing that is applied to an occupant of a vehicle;
- an urger that is capable of transmitting urging force to the spool;
- a rotary member that is disposed between the spool and the urger;
- and
- a spring foamed in a helical shape, that is disposed at the rotary member, rotation of the spring relative to the rotary member being limited due to the spring being wound on the rotary member to control transmission of the urging force from the urger to the spool, and a movement force toward one end side being exerted due to the spring being wound on the rotary member, and a winding force onto the rotary member being larger at the one end side than at the other end side.
Dependencies are inferred from the claim text.