Extended low tension range dual tension safety belt retractor

摘要

A safety belt retractor has an extended low tension range dual tensioning and rewind means including a reel rewind spring means for biasing the reel in a belt rewind direction under the urging of a first bias, tension reducing means for providing a second rewind bias of a lower value on said reel than the first bias to provide a reduced tension on a safety belt, activating means for activating the tension reducing means in response to reel rotation in a predetermined manner and means for deactivating such tension reducing means in response to reel rotation under the urging of the second bias including the provison of a spiral cam surface mounted to the retractor frame and presenting a spiral surface having an extent of more than one whole revolution about a spiral center, a cam follower provided to be moved along the spiral surface, means for driving the cam follower along such cam surface in response to rotation of the reel and means operated by radial displacement of the cam follower relative to the spiral center due to travel of more than one full revolution of the follower about such center for deactivating the tension reducing means.