| 摘要 |
A device (1) for indicating a predetermined tension of a driving belt (31) comprises a base (8), a hub (9) on the base for the drive belt, two links (10) pivotally connected to the base and having outer abutments (11) for the drive belt, and a helical tension spring (12) which is attached to the links (10) and which exert a reactional force corresponding to the predetermined tensional force. The links (10) are arranged for synchronized pivotal movement between two stable end positions for snap-over movement past the centre axis of the hub (9). When the links assume one (C) of their end positions, the drive belt (31) may be moved into abutment against the abutments (11) and the hub (9) and may be tightened while the links (10) are pivoted in synchrony against the action of the helical tension spring (12) until the drive belt extends along a straight line between the abutments. The predetermined tensional force and the reactional force now correspond to one another and thus effect the snap-over movement of the links to the opposite end position of the latter. The very snap-over is the indication of obtainment of the predetermined tension of the drive belt (31). |
