Modular seatbelt retractor

Abstract

A belt retractor (40) having a belt reel (14), a seat belt (12) which can be wound thereon to form a belt reel, and at least one first assembly, the first assembly being arranged coaxially with the axis of rotation of the belt reel (14) and in series with the belt reel (14). The belt retractor is especially adapted for mounting inside the frame member of a motor vehicle seat.

1 . A belt retractor comprising,
 a belt reel,   a seat belt which can be wound up into the belt reel,   a first assembly; and   the first assembly is disposed coaxially with the axis of rotation of the belt reel and in series with the belt reel.   
     
     
         2 . A belt retractor according to  claim 1 , further comprising,
 the first assembly has smaller or identical outer dimension in the direction perpendicular to the axis of rotation of the belt reel than the maximum outer diameter of the belt reel when the seat belt is fully wound on the belt reel.   
     
     
         3 . A belt retractor according to  claim 1  further comprising,
 the belt retractor is mounted on a first web arranged between the belt reel and the first assembly. 
 
     
     
         4 . A belt retractor according to  claim 1  further comprising,
 a second web is provided for mounting the belt retractor, which second web is spaced apart from the first web in the axial direction of the belt retractor. 
 
     
     
         5 . A belt retractor according to  claim 1  further comprising,
 a second assembly is provided which is coaxial and arranged in series with the belt reel and with the first assembly. 
 
     
     
         6 . A belt retractor according to  claim 4  further comprising in that the second web is arranged between the first assembly and a second assembly which is coaxial and arranged in series with the belt reel and with the first assembly. 
     
     
         7 . A belt retractor according to  claim 5  further comprising,
 the first or the second assembly is a pyrotechnic belt tensioner having a tensioner drive tube with a pyrotechnically drivable drive device provided therein, and the drive device drives a drive movement of the belt reel is transmitted by a drive wheel, wherein 
 the tensioner drive tube has a linear section and a curved section disposed at an end of the linear section, and 
 the tensioner drive tube is arranged such that the linear section runs parallel to the axis of rotation of the belt reel and is directed with the curved section tangentially in the circumferential direction toward the drive wheel. 
 
     
     
         8 . A belt retractor according to  claim 7  further comprising,
 the tensioner drive tube is arranged such that the linear section and the curved section are arranged in a plane parallel to the axis of rotation of the belt reel. 
 
     
     
         9 . A belt retractor according to  claim 5  further comprising,
 the first assembly or the second assembly is formed by a force limiting device having a first torsion bar disposed coaxially with the belt reel. 
 
     
     
         10 . A belt retractor according to  claim 9  wherein,
 the force limiting device comprises a second torsion bar arranged in series with the first torsion bar. 
 
     
     
         11 . A belt retractor according to  claim 9  further comprising,
 a tubular extension, which is arranged coaxially with the axis of rotation of the belt reel and into which the first or the second torsion bar projects, is provided on an end face of the belt reel. 
 
     
     
         12 . A belt retractor according to  claim 11  further comprising,
 the belt retractor with the tubular extension is mounted on the first or a second web. 
 
     
     
         13 . A belt retractor according to  claim 5  further comprising,
 the first assembly or the second assembly or a third assembly is formed by a reversible belt tensioner having an electric motor, wherein 
 the electric motor is arranged with a drive shaft guided out coaxially with the axis of rotation of the belt reel. 
 
     
     
         14 . A belt retractor according to  claim 6  further comprising, the first web and the second web are coupled to a vehicle housing member for reacting to torsional forces acting on the first or the second assembly. 
     
     
         15 . A belt retractor according to  claim 1  further comprising, the belt retractor is contained within a housing member of a motor vehicle seat structure. 
     
     
         16 . A belt retractor according to  claim 15  further comprising, wherein the housing member forms an upper generally horizontal member connecting with and positioned between a pair of vertical struts. 
     
     
         17 . A belt retractor according to  claim 1  further comprising, the housing member is an elongated member defining an elongated interior cavity with the belt reel and the first assembly contained within the interior cavity. 
     
     
         18 . A belt retractor according to  claim 17  further comprising, the housing member is generally U-shaped in cross-section.