Self-tightening mechanism

摘要

A self-tightening mechanism mounted on a seat having a back portion. The self-tightening mechanism including a drum coupled to the back portion, a band wrapped about the drum inhibiting rotation thereof and having a first end and a second end. A tightening mechanism coupled to the first end and the second end such that a force applied to the back portion in either of two opposing directions produces a tension in the band adjacent either one of the first end and the second end and a corresponding loosening of the band adjacent the other end. The tightening mechanism including a lever pivotable about a fixed pivot point to convert a portion of the tension to reduce the loosening.