Retractable seatbelt apparatus

Abstract

A pretensioner including a cylinder in which a piston slides. A side of the pipe attached to a bracket is curved at a predetermined angle. One linear portion of the pipe serves as the cylinder, and the other linear portion of the pipe serves as a gas-generator accommodating portion that accommodates a gas generator. A wire passing hole through which a wire passes is bored coaxially with the center axis of the piston sliding portion of the pipe. The piston sliding portion and the gas-generator accommodating portion can be formed of the single pipe, and the gas generator and the wire can be prevented from interfering with each other.

1 . A pretensioner for increasing the restraint force of a seat belt on an occupant comprising: 
 a connecting member connected to a piston, the piston being configured to be moved by pressure of gas generated by a gas generator,    a bent tubular member comprising a linear portion in which the piston is slidably fitted and a gas-generator accommodating portion in which the gas generator is accommodated; and    wherein the connecting member extends from the piston inside the tubular member to a location outside the tubular member and is operatively connected to the seat belt; and    wherein the piston is configured to move only within the linear portion so that when the piston moves the connecting member moves the seatbelt in order to increase the restraint force on the occupant.    
   
   
       2 . The pretensioner of  claim 1 , wherein the tubular member includes a bend so that the gas-generator accommodating portion and the linear portion form a generally u-shaped tube.  
   
   
       3 . A pretensioner for increasing the restraint force of a seat belt on an occupant comprising: 
 a connecting member connected to a piston, the piston being configured to be moved by pressure of gas generated by a gas generator,    a bent tubular member comprising a linear portion having an approximately constant inner diameter in which the piston is slidably fitted and a gas-generator accommodating portion in which said gas generator is accommodated; and    wherein the connecting member is operatively connected to the seat belt so that when the piston moves the connecting member pulls the seat belt, and    wherein the gas-generator accommodating portion extends in a direction that is not parallel with the linear portion.    
   
   
       4 . The pretensioner of  claim 3 , wherein the connecting member is configured to move to apply tension to a lap belt of a seat belt.  
   
   
       5 . A seat belt system comprising: 
 a lap belt configured to be positioned across the lap of an occupant of a vehicle seat;    a pretensioner for increasing the restraint force of a seat belt on an occupant comprising: a connecting member connected to a piston, the piston being configured to be moved by pressure of gas generated by a gas generator, and a generally u-shaped bent tubular member comprising a linear portion in which the piston is slidably fitted and a gas-generator accommodating portion in which said gas generator is accommodated, and wherein the linear portion and the accommodating portion extend in different directions; and    wherein the connecting member is operatively connected to the lap belt so that when the piston moves the lap belt is pulled to thereby restrain the occupant.    
   
   
       6 . The system of  claim 5 , wherein the tubular member includes a hole bored coaxially with said piston, the connecting member comprising a wire positioned to pass through the hole.  
   
   
       7 . The system of  claim 5 , wherein movement of the piston within the linear portion is limited to a single direction.  
   
   
       8 . A seat belt system comprising: 
 a seat belt and a pretensioner for increasing the restraining force of the seat belt on an occupant of a vehicle seat;    wherein the pretensioner comprises: a bent tubular member comprising a linear portion; a piston slidably positioned to move only within the linear portion of the tubular member; and a gas generator located in another portion of the tubular member; and    a wire connected to the piston;    wherein the wire is positioned so that when the piston moves within the linear portion due to gas pressure generated by a gas generator the wire moves to thereby move the seat belt.    
   
   
       9 . The system of  claim 8 , wherein the wire is located both within the tubular member and outside the tubular member.  
   
   
       10 . The system of  claim 8 , wherein movement of the piston is limited to a single direction.  
   
   
       11 . The system of  claim 8 , wherein the piston includes a plurality of balls that are forced against an inner surface of the tubular member when the piston is forced in a direction opposite to the single direction.  
   
   
       12 . The pretensioner of  claim 8 , wherein an angle between a line extending parallel to the another portion of the tubular member accommodating the gas generator and a line extending along the axis of movement of the piston is acute.  
   
   
       13 . The pretensioner of  claim 8 , wherein the linear portion and the gas-generator accommodating portion of the bent tubular member are integrally formed.  
   
   
       14 . A seat belt pretensioner for protecting an occupant of a vehicle, the pretensioner comprising: 
 a curved tubular member including a linear portion located adjacent to one end of the tubular member; wherein the linear portion has a substantially constant diameter and contains a slidable piston;    a gas generator for supplying gas pressure to move the piston, wherein the gas generator is located within another end of the tubular member;    a wire connected to the piston and positioned to pass through an opening in the tubular member so that when the piston moves within the linear portion due to gas pressure generated by a gas generator the wire also moves to thereby move the seat belt in order to increase a restraining force on the occupant.    
   
   
       15 . The pretensioner of  claim 14 , wherein the tubular member is curved greater than ninety degrees.