Webbing winding device

A webbing winding device having a pre-tensioner for tensioning a webbing for restraining a passenger in a passenger restraining direction in an emergency deceleration of a vehicle, said webbing winding device comprising:

• a winding shaft to which an end of said webbing is fixed;
• and
• a gear train mechanism comprising a plurality of gears including an internal gear, a sun gear and a planet gear which meshes with these gears, wherein a driving gear which receives an external driving force when said pre-tensioner is actuated, is driven from starting end position to a terminating end position, which are set in advance, so as to rotate the winding shaft in a direction for retracting the webbing, and when the driving of said driving gear is completed, said internal gear is supported movably along a pitch line of said internal gear so that said planet gear is capable of rotating in a direction corresponding to said webbing retracting direction.

A webbing winding device having a pre-tensioner for tensioning a webbing for restraining a passenger in a passenger restraining direction in an emergency deceleration of a vehicle, said webbing winding device comprising:

• a winding shaft to which an end of said webbing is fixed;
• and
• a gear train mechanism comprising a plurality of gears including a pinion and a rack which meshes with said pinion, wherein said rack, which receives an external driving force when said pre-tensioner is actuated, is driven from a starting end position to a terminating end position, which are set in advance, so as to rotate said winding shaft in a webbing winding direction and a part or all of said rack is supported to be radially movable relative to said winding shaft along the pitch line of said rack so that said pinion is able to continue to be rotated in a direction corresponding to said webbing retracting direction when the driving of said rack is completed.

A webbing winding device having a pre-tensioner for tensioning a webbing for restraining a passenger in a passenger restraining direction in an emergency deceleration of a vehicle, said webbing winding device comprising:

• a winding shaft to which an end of said webbing is fixed;
• and
• a gear train mechanism comprising a plurality of gears arranged in such a manner that adjacent gears mesh with each other, wherein an external driving gear of said gear train receiving a driving force when said pre-tensioner is actuated is driven from a preliminarily set starting end position to a terminal end position so as to rotate said winding shaft in a direction for retracting the webbing and when the driving of said driven gear is completed, at least a pair of adjacent, engaged gears of said gear train are moved relative to each other in an axial direction relative to said winding shaft to a disengaging position so as to enable said winding shaft to continue to be rotated in the direction for retracting the webbing by inertial force.

A webbing winding device having a pre-tensioner for tensioning a webbing for restraining a passenger in a passenger restraining direction in an emergency deceleration of a vehicle, said webbing winding device comprising:

• a winding shaft to which an end of said webbing is fixed;
• and
• a gear train mechanism comprising a plurality of gears arranged in such a manner that adjacent gears mesh with each other, wherein an external driving gear of said gear train receiving a driving force when said pre-tensioner is actuated is driven from a preliminarily set starting end position to a terminal end position so as to rotate said winding shaft in a direction for retracting the webbing and when the driving of said driven gear is completed, at least a pair of adjacent, engaged gears of said gear train are moved relative to one another orthogonally of the pitch line of the engaged gears to a disengaging position so as to enable said winding shaft to continue to be rotated in the direction for retracting the webbing by inertial force.