| 摘要 |
<p>A uni-directional friction brake unit (2) comprising a unit support (4), a friction wheel (10) rotatably mounted with respect to the unit support, a flexible, substantially inextendible band (26) embracing the friction wheel over a major portion of its peripheral surface, one end of the band being fixedly coupled to the unit support, means (46) for frictionally coupling the band to the friction wheel over the major portion, elastic biasing means (30) coupling an opposite end of the band to the unit support for biasing the band into frictional engagement with the wheel and means for rotating the friction wheel with respect to the unit support. The arrangement being such that rotation of the wheel in a first sense (50) results in tightening the band around the friction wheel so as to resist the rotation, while rotation of the friction wheel in a second and opposite sense (52) results in loosening the band with respect to the friction wheel.</p> |
