Traction drive able to run in both directions of rotation

摘要

The drive, running in both directions, is usually a chain drive. It has a tensioning device (4) for the chain (1), which has two tensioning bodies (9,10), one for the traction branch and one for the idling branch. Each tensioning body is fixed to a lever (5,6) turning round an axis (7,8). The two levers can create a contrary rotation motion when engaged with each other. The levers are held against each other by a pre-tensioning element. The levers may be engaged with a freewheeling device, locking in the direction for a reduction of the pre-tension force.