Belt Retractor With a Switchable Force-Limiting Device

摘要

A vehicle seat belt retractor with a belt shaft (10) and a coupled profile head lockable to a housing. A force-limiting device has at least two elements (11, 12) between profile head and belt shaft (10). Free ends (15, 16) of the force-limiting elements (11, 12) are coupled to each other by a connecting tube (13) via a coupling element (18). The coupling element (18) has a hook-shaped spring element with a locking hook (19) which slides over the connecting tube (13) when the belt shaft (10) rotates and engages in a locking groove (20) to couple the connecting tube (13) to the belt shaft (10). At a preset angle of rotation of the belt shaft (10) is reached, the bridging device releases the coupling element (18) for the locking hook (19) to latch into the connecting tube locking groove (20).

主权项

1. A belt retractor for a seat belt of a motor vehicle comprising a belt shaft rotatably mounted in a housing and with a profile head coupled to the belt shaft and lockable with respect to the housing, a force limiting device having first and second force limiting elements arranged between the profile head and the belt shaft to allow a force limited rotation of the belt shaft in the direction of the belt extension when the locked profile head is locked and when a force limiting level preset by the force limiting device is exceeded, and the first force limiting element is connected by a first end thereof to the profile head, and the second force limiting element is connected by a first end thereof to the belt shaft, and wherein second ends of the first force limiting element and of the second force limiting element are coupled to one another by means of a connecting tube, for coupling of the connecting tube to the belt shaft, a coupling element is provided via which the connecting tube can be coupled therewith at a preset angle of rotation of the belt shaft, and wherein furthermore the coupling element arranged between the belt shaft and the connecting tube is configured as a hook-shaped spring element with a locking hook, which, upon rotation of the belt shaft including the coupling element, slides over the outer periphery of the connecting tube, which, after reaching the preset angle of rotation of the belt shaft drops into a locking groove configured on the periphery of the connecting tube, and thus couples the connecting tube to the belt shaft during initial rotation coupling element with respect to the connecting tube, the coupling element is supported on the surface of the connecting tube by means of a bridging device, and thus the locking hook, when passing over the locking groove of the connecting tube, is kept out of engagement with the locking groove, and that, when the preset angle of rotation of the belt shaft is reached, the bridging device releases the coupling element in order for the locking hook to latch with the locking groove of the connecting tube.