Webbing retractor

Abstract

A webbing retractor which, by causing relative rotation between a prime mover rotating body and a rotating disc, connects the prime mover rotating body and a driven shaft which is connected to a take-up shaft of a webbing belt. A planet gear is pivotally supported at a plate having a braking piece and meshes with a sun gear. The plate is supported so as to be swingable around the sun gear. When the sun gear is driven to rotate at greater than a predetermined speed, the planet gear begins to circle around the sun gear against urging force of a spring attached to the plate, and makes the plate rotate such that the braking piece slidingly contacts the friction ring. Due to this braking, the rotating disc connected to the friction ring rotates relative to the prime mover rotating body.

1 . A webbing retractor for an elongated, strip-shaped webbing belt used for application to a body of a vehicle occupant, the webbing retractor comprising: 
 a take-up shaft for taking the webbing belt up around itself, which take-up shaft is rotatably held, and to which one end of the webbing belt is anchored;    a driven shaft connected to the take-up shaft;    a prime mover rotating body rotatably supported relative to and coaxially with the driven shaft;    a rotating member supported coaxially with both the prime mover rotating body and the driven shaft, and rotatable relative to both the prime mover rotating body and the driven shaft;    connecting members for connecting the prime mover rotating body and the driven shaft, by interlocking with relative rotation of the rotating member with respect to the prime mover rotating body, so as to transmit rotation of the prime mover rotating body to the driven shaft;    a driving mechanism, including a drive source, for driving rotation of the prime mover rotating body in a predetermined direction;    a braking mechanism for braking rotation of the rotating member such that relative rotation of the rotating member with respect to the prime mover rotating body arises;    wherein the driven shaft has a peripheral surface, and the connecting members are held at the prime mover rotating body so as to be able to approach and move away from the driven shaft, and when the prime mover rotating body is rotated, the connecting members contact the peripheral surface of the driven shaft due to the relative rotation, and connect the prime mover rotating body and the driven shaft; and    wherein a plurality of teeth are formed at the peripheral surface of the driven shaft, and the connecting members have pawl shapes which can engage with any of the teeth, and at least one of the connecting members contacts the tooth of the driven shaft so as to engage with the tooth, and connects the prime mover rotating body and the driven shaft.    
   
   
       2 - 8 . (canceled)  
   
   
       9 . A webbing retractor for an elongated, strip-shaped webbing belt used for application to a body of a vehicle occupant, the webbing retractor comprising: 
 a take-up shaft for taking the webbing belt up around itself, which take-up shaft is rotatably held, and to which one end of the webbing belt is anchored;    a driven shaft connected to the take-up shaft;    a prime mover rotating body rotatably supported relative to and coaxially with the driven shaft;    a rotating member supported coaxially with both the prime mover rotating body and the driven shaft, and rotatable relative to both the prime mover rotating body and the driven shaft;    connecting members for connecting the prime mover rotating body and the driven shaft, by interlocking with relative rotation of the rotating member with respect to the prime mover rotating body, so as to transmit rotation of the prime mover rotating body to the driven shaft;    a driving mechanism, including a drive source, for driving rotation of the prime mover rotating body in a predetermined direction;    a braking mechanism for braking rotation of the rotating member such that relative rotation of the rotating member with respect to the prime mover rotating body arises;    wherein the braking mechanism brakes the rotating member when the prime mover rotating body is driven to rotate at greater than a predetermined speed.    
   
   
       10 . A webbing retractor for an elongated, strip-shaped webbing belt used for application to a body of a vehicle occupant, the webbing retractor comprising: 
 a take-up shaft for taking the webbing belt up around itself, which take-up shaft is rotatably held, and to which one end of the webbing belt is anchored;    a driven shaft connected to the take-up shaft;    a prime mover rotating body rotatable supported relative to and coaxially with the driven shaft;    a rotating member supported coaxially with both the prime mover rotating body and the driven shaft, and rotatable relative to both the prime mover rotating body and the driven shaft;    connecting members for connecting the prime mover rotating body and the driven shaft, by interlocking with relative rotation of the rotating member with respect to the prime mover rotating body, so as to transmit rotation of the prime mover rotating body to the driven shaft;    a driving mechanism, including a drive source, for driving rotation of the prime mover rotating body in a predetermined direction;    a braking mechanism for braking rotation of the rotating member such that relative rotation of the rotating member with respect to the prime mover rotating body arises;    wherein the braking mechanism connects the driving mechanism such that motion of the braking mechanism for braking can be transmitted from the driving mechanism.    
   
   
       11 . A webbing retractor for an elongated, strip-shaped webbing belt used for application to a body of a vehicle occupant, the webbing retractor comprising: 
 a take-up shaft for taking the webbing belt up around itself, which take-up shaft is rotatable held, and to which one end of the webbing belt is anchored;    a driven shaft connected to the take-up shaft;    a prime mover rotating body rotatable supported relative to and coaxially with the driven shaft;    a rotating member supported coaxially with both the prime mover rotating body and the driven shaft, and rotatable relative to both the prime mover rotating body and the driven shaft;    connecting members for connecting the prime mover rotating body and the driven shaft, by interlocking with relative rotation of the rotating member with respect to the prime mover rotating body, so as to transmit rotation of the prime mover rotating body to the driven shaft;    a driving mechanism, including a drive source, for driving rotation of the prime mover rotating body in a predetermined direction;    a braking mechanism for braking rotation of the rotating member such that relative rotation of the rotating member with respect to the prime mover rotating body arises;    wherein the braking mechanism brakes the rotating member interlockingly with driving rotation of the prime mover rotating body by the driving mechanism.    
   
   
       12 - 14 . (canceled)  
   
   
       15 . A webbing retractor for an elongated, strip-shaped webbing belt used for application to a body of a vehicle occupant, the webbing retractor comprising: 
 a take-up shaft for taking the webbing belt up around itself, which take-up shaft is rotatable held, and to which one end of the webbing belt is anchored;    a driven shaft connected to the take-up shaft;    a prime mover rotating body rotatable supported relative to and coaxially with the driven shaft;    a rotating member supported coaxially with both the prime mover rotating body and the driven shaft, and rotatable relative to both the prime mover rotating body and the driven shaft;    connecting members for connecting the prime mover rotating body and the driven shaft, by interlocking with relative rotation of the rotating member with respect to the prime mover rotating body, so as to transmit rotation of the prime mover rotating body to the driven shaft;    a driving mechanism, including a drive source, for driving rotation of the prime mover rotating body in a predetermined direction;    a braking mechanism for braking rotation of the rotating member such that relative rotation of the rotating member with respect to the prime mover rotating body arises;    wherein the prime mover rotating body has an external gear which is ring shaped and has external teeth for connection to the driving mechanism such that the external gear can be driven and rotated; a base portion having a holding portion for holding the plurality of connecting members, the base portion being pivotally supported coaxially with the rotating member; and at least one torque limiter provided between the external gear and the base portion, so as to be able to transmit torque in a predetermined range to the base portion from the external gear.    
   
   
       16 . A webbing retractor for an elongated, strip-shaped webbing belt used for application to a body of a vehicle occupant, the webbing retractor comprising: 
 a take-up shaft for taking the webbing belt up around itself, which take-up shaft is rotatable held, and to which one end of the webbing belt is anchored;    a driven shaft connected to the take-up shaft;    a prime mover rotating body rotatable supported relative to and coaxially with the driven shaft;    a rotating member supported coaxially with both the prime mover rotating body and the driven shaft, and rotatable relative to both the prime mover rotating body and the driven shaft;    connecting members for connecting the prime mover rotating body and the driven shaft, by interlocking with relative rotation of the rotating member with respect to the prime mover rotating body, so as to transmit rotation of the prime mover rotating body to the driven shaft;    a driving mechanism, including a drive source, for driving rotation of the prime mover rotating body in a predetermined direction;    a braking mechanism for braking rotation of the rotating member such that relative rotation of the rotating member with respect to the prime mover rotating body arises;    further comprising a control unit for controlling operation of the driving mechanism, wherein the control unit effects control so as to cause the driving mechanism to operate when a rate of change in deceleration at a time when the vehicle decelerates is greater than or equal to a predetermined value.    
   
   
       17 - 20 . (canceled)