A seat belt retractor includes a housing including a pair of side walls facing each other, a winding drum configured to wind up a webbing, the winding drum being housed between the pair of side walls so as to be rotatable in a winding direction and a pull-out direction of the webbing, a lock member provided at a first end portion, of the winding drum, located on one side in an axial direction of the winding drum, a biasing member including one end portion attached to the first end portion of the winding drum, the other end portion attached to the lock member, and a connecting portion connecting the one end portion and the other end portion, a shaft member attached to the first end portion of the winding drum, and a cover member attached to the housing.

In a belt tensioner (10) for a seat belt comprising an elongate pressure reservoir (12), a piston (18) movably supported in the pressure reservoir (12) in the longitudinal direction to which piston pressurized fluid can be applied and which in this way can be moved in a tensioning direction (S), a mechanical thrust means (20) interacting with the piston, the thrust means interacting with a gearwheel (22) and driving the same in the case of restraint, and comprising a stop (24) on which the piston (18) abuts in the tensioning direction in a final position, it is provided that between the piston (18) and the thrust means (20) a spacer (30) in the form of a separate member is provided which is dimensioned such that in the final position of the piston (18) the thrust means (20) is urged past the stop (24) by said spacer. Furthermore there is provided a method of mounting a belt tensioner of this type.

The invention provides in a best tensioner (10), especially a rotary tensioner, for a seat belt comprising an elongate and preferably cylindrical pressure cylinder (129, a piston (18) movably supported in the pressure cylinder (12) in the longitudinal direction which is adapted to be pressurized with fluid under pressure and thus to be moved into a tensioning direction (S), a thrust means (20) interacting with the piston (18) and a stop (24) provided on the inside (38) of the pressure cylinder (12) to which the piston (18) can be adjacent in the tensioning direction (S) at an end position at which the piston (18) seals the pressure cylinder (12), that the stop (24) is made of a plastically deformable material and is plastically deformed by the piston (18) at the end position so that the piston is in sealing contact with the inside of the pressure cylinder (12).

A webbing take-up device that includes: a cut-off section that cuts off transmission of rotation load along a rotation force transmission route from a second rotation force transmission mechanism to a spool via a first rotation force transmission mechanism due to the rotation load in a pull-out direction becoming a predetermined value or greater; and a resistance section that resists the rotation load during transmission of the rotation load, and that suppresses transmission of the rotation load along the rotation force transmission route in a case in which the rotation load is less than the predetermined value.

A reversible seat belt tensioner including a rotationally operable plastic driven gear (1), and a drive moved with a belt shaft of the belt tensioner. At least one coupling pawl (4) is provided on the drive gear, engaging a gearing of the drive gear upon activation of the reversible belt tensioner, and in a load-transmitting position produces a linkage between the driven gear (1) and the drive gear. A support ring (3) made of a material having a greater strength than the driven gear (1) is provided and is connected to the driven gear (1) for with a projection (21, 22) which into a recess (15, 16) of the driven gear (1). The recess (15, 16) positioned such that the coupling pawl (4) is braced against the driven gear (1) via the projection (21, 22) which engages in the recess (15, 16).

A webbing take-up device includes clutch weights. The clutch weights are supported at the base and include engaging portions. The clutch weights move to a rotation diameter direction outer side when the base is rotated, and are capable of transmitting rotary force applied to the base to the spool. The webbing take-up device is provided with a stopper that is capable of relative rotating relative to the base and that is provided with engaged holes, each including an allowing portion and a restricting portion. The allowing portions allow movement of the engaging portions to the rotation diameter direction outer side when the base is rotating to one side. The restricting portions restrict movement of the engaging portions to the rotation diameter direction outer side when the base is rotating to the other side. The restricting portions are formed integrally with the allowing portions.

A belt retractor includes a retractor frame (10) having first and second end faces (10a, 10b) between which a belt reel (12) is pivoted. The belt retractor further includes a belt tensioner and a spring cassette (30) having a helical spring (26) coupled to the belt reel (12). The spring cassette (30) is arranged between the first end face (10a) of the retractor frame (10) and at least one component of the belt tensioner. A method of fitting such belt retractor includes mounting the spring cassette (30) on a component of the belt tensioner, especially on an inside of a tensioner casing (22) and mounting the belt tensioner including the spring cassette (30) on the retractor frame (10), especially on an end wall (10a) of the retractor frame (10). An alternative fitting method includes mounting the spring cassette (30) on an end wall (10a) of the retractor frame (10) and attaching the belt tensioner to the spring cassette (30) mounted on the end wall (10a) of the retractor frame (10).

A belt tensioner for a seat belt system comprises a pinion (10) pivoted about an axis of rotation A which is adapted to be coupled to a best reel of a belt retractor, a drive unit, a force transmission element (12) and a guide means. By activating the drive unit the force transmission element (12) is moved along the guide means so that it engages in the pinion (10). The guide means includes a portion (16) which is deformable in a direction x perpendicular to the axis of rotation A of the pinion (10) and to the direction of movement y of the force transmission element (12).

A power transmission mechanism (19) for transmitting power from a motor (34) to a spindle (12) having a clutch housing (50), a pawl (41) engageable with the clutch housing (50), a gear wheel (57) which holds the pawl (41) and rotates with the rotation of the motor (34), an outer gear cover (26), and a friction ring (42) engaging with the pawl (41) and held on the outer gear cover (26) by frictional force. The friction ring (42) is provided with a protruding portion (42a) which engages with an engagement groove (41b) of the pawl (41), and a plurality of contact pieces (42b) in contact with an outer peripheral surface of a small diameter ring portion (26c) of the outer gear cover (26) and press radially against the outer peripheral surface towards an inner side The friction ring can be easily coupled to the outer gear cover.

A webbing take-up device includes a second clutch that transmits rotation of a motor to a spool. The second clutch includes a base including a first spring catch portion, a clutch gear, a clutch spring including a coil portion, having an end portion at one side caught to the first spring catch portion, and a lever that includes a second spring catch portion catching an end portion at another side of the clutch spring, and that enlarges diameter of the coil portion to abut the clutch gear by moving the end portion at the another side of the clutch spring toward one side in the circumferential direction of the base. A terminal end of the end portion at the one side of the clutch spring abuts the first spring catch portion when the lever is rotated toward the one side in the circumferential direction of the base.