A seat belt retractor includes a base frame, a spool journalled to the base frame, a webbing wound around the spool, and a motor for rotating the spool. A speed-reduction mechanism is interposed between the motor and the spool. The speed-reduction mechanism includes at least one transmission train w
A seat belt retractor includes a base frame, a spool journalled to the base frame, a webbing wound around the spool, and a motor for rotating the spool. A speed-reduction mechanism is interposed between the motor and the spool. The speed-reduction mechanism includes at least one transmission train with a predetermined gear ratio, a common transmission element connected to the transmission train, and a resistant torque device connected to the transmission train. The common transmission element transmits rotation of the motor to the spool when the torque of the rotation is smaller than the preset value. Winding of the webbing is made based on the wearing condition of the webbing and the running condition of the vehicle.
대표청구항▼
1. A seat belt retractor, comprising: a base frame, a spool having a spool shaft journalled to the base frame, a webbing wound around the spool, a return spring connected to the spool for winding the webbing by a return force thereof, a motor connected to the spool for winding the spool, wind
1. A seat belt retractor, comprising: a base frame, a spool having a spool shaft journalled to the base frame, a webbing wound around the spool, a return spring connected to the spool for winding the webbing by a return force thereof, a motor connected to the spool for winding the spool, winding of the webbing being made by one of the return spring and the motor by switching, and a speed-reduction mechanism interposed between the motor and the spool, said speed-reduction mechanism including a transmission train with a predetermined reduction gear ratio, said transmission train having a planetary gear unit having an internal gear with ratchet teeth formed on an outer periphery of the internal gear, and switching means for connecting the transmission train to the spool shaft corresponding to a driving signal obtained from an external unit, said switching means having pawl mechanism engaging one of the ratchet teeth to fix rotation of the internal gear. 2. A seat belt retractor as claimed in claim 1, wherein said driving signal includes at least one of a state signal obtained by movement of an occupant wearing the webbing, and an external signal obtained from detecting means installed in a vehicle during running of the vehicle. 3. A seat belt retractor as claimed in claim 2, wherein upon receiving the external signal, said switching means switches the transmission train so that the webbing is wound by the return spring at a large reduction ratio. 4. A seat belt retractor as claimed in claim 1, wherein said switching means, upon receiving the driving signal from the external unit, actuates to secure a part of transmission elements disposed in the speed-reduction mechanism to thereby switch the train. 5. A seat belt retractor, comprising: a base frame, a spool having a spool shaft journalled to the base frame, a webbing wound around the spool, a return spring connected to the spool for winding the webbing by a return force thereof, a motor connected to the spool for winding the spool, winding of the webbing being made by one of the return spring and the motor by switching, and a speed-reduction mechanism interposed between the motor and the spool, and including a transmission train with a predetermined reduction gear ratio, said transmission train having an internal gear with ratchet teeth; and switching means for connecting the transmission train to the spool shaft corresponding to a driving signal obtained from an external unit, said switching means including a pawl mechanism having two pawls journalled by shafts and engaging the ratchet teeth to fix rotation of the internal gear, said two pawls having a first pawl and a second pawl, said first pawl pivoting about the shaft by excitation of a solenoid to engage one of the ratchet teeth, and then allowing the second pawl to engage another of the ratchet teeth. 6. A seat belt retractor as claimed in claim 5 wherein said pawl mechanism further includes a spring connected to the first pawl urging the first pawl to disengage from the ratchet teeth after cancelling excitation of the solenoid.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.