| 摘要 |
32 BELT TENSIONER WITH SPRING ACTUATED BAND BRAKE DAMPING A belt tensioning device having an improved damping mechanism for damping movements of the pivoted structure rotatably carrying the pulley with respect to the fixed structure. The damping mechanism includes a strap and a ring mounted on their respective fixed and pivoted structures, and with respect to one another such that the strap engages the ring with a gripping action sufficient to provide (1) a relatively high resistance to frictional sliding movement between the strap and ring in one direction corresponding to the direction of untensioning of the belt with the pulley, and (2) a relatively low resistance to frictional sliding movement between the strap and ring in an opposite direction corresponding to the direction of belt tensioning. A spring is included in the mount for enabling the relatively high resistance and relatively low resistance to vary in response to the existence of predetermined vibrations such that the gripping action between strap and ring is relieved sufficiently to enable movement therebetween in both directions to take place at substantially reduced resistance levels. |
