Webbing take up device

Abstract

In a webbing take-up device, the overall lengths of pistons are set shorter than a separation between bent portions. Moreover, the overall length of a piston is set even shorter than the shorter separation out of a separation between the bent portions, and a separation between bent portions. Pistons do not straddle the bent portion and the bent portion, and do not straddle the bent portion and the bent portion. This enables the pistons to easily arrive at their initial disposed positions inside a cylinder.

1 . A webbing take-up device comprising:
 a spool that takes up a webbing by rotating in a take-up direction;   a hollow tube shaped cylinder in which a plurality of bent portions are set at an intermediate portion in an axial line direction of the cylinder, the axial line direction of the cylinder being changed by the bent portions;   a plurality of moving members having flexibility, that are disposed in a row along the axial line direction inside the cylinder, the moving members having a shorter length in the axial line direction than a length from a first bent portion to a last bent portion through which the moving members pass from being inserted into the cylinder and until arriving at disposed positions; and   a gas generation means that is provided at a base end portion of the cylinder, that supplies gas to the cylinder, and that moves the plurality of moving members toward a leading end side of the cylinder by pressure of the gas and rotates the spool in the take-up direction.   
     
     
         2 . The webbing take-up device of  claim 1 , wherein the length in the axial line direction of each of the plurality of moving members is set to be shorter than an interval between adjacent bent portions which are disposed nearest to each other in the axial line direction, the adjacent bent portions being among the bent portions through which each of the moving members passes from being inserted into the cylinder until arriving at the disposed position. 
     
     
         3 . The webbing take-up device of  claim 2 , wherein the length in the axial line direction of each of the plurality of moving members is set to be shorter than an interval between adjacent bent portions which are disposed nearest to each other in the axial line direction, the adjacent bent portions being between both axial line direction ends of the cylinder. 
     
     
         4 . A webbing take-up device comprising:
 a spool that takes up a webbing by rotating in a take-up direction;   a hollow tube shaped cylinder in which a bent portion is set, an axial line direction of the cylinder being changed by the bent portion;   a plurality of moving members having flexibility, that are disposed in a row along the axial line direction inside the cylinder, the moving members having a shorter length in the axial line direction than an axial line direction length of the bent portion; and   a gas generation means that is provided at a base end portion of the cylinder, that supplies gas to the cylinder, and that moves the plurality of moving members toward a leading end side of the cylinder by pressure of the gas and rotates the spool in the take-up direction.   
     
     
         5 . The webbing take-up device of  claim 4 , wherein:
 the length in the axial line direction of a moving member disposed at the bent portion of the cylinder becomes shorter on progression toward a side of a center of curvature of the bent portion, and   an end face of the moving member disposed at the bent portion of the cylinder is an inclined face with respect to a direction orthogonal to an axis of the moving member in a natural state of the moving member.   
     
     
         6 . The webbing take-up device of  claim 4 , wherein the moving members that are adjacent inside the bent portion of the cylinder are disposed separated from each other in the axial line direction at an outer side in a direction of a radius of curvature of the bent portion. 
     
     
         7 . The webbing take-up device of  claim 6 , wherein the adjacent moving members inside the bent portion of the cylinder are integrally coupled together by a coupling portion. 
     
     
         8 . The webbing take-up device of  claim 7 , wherein the coupling portion is broken by the moving members being disposed inside the bent portion.