| 摘要 |
1. A device propelled by muscle power in particular for a vehicle having at least three support points, comprising a pair of levers (1, 1a; 1', 1'a) articulated about a common axis (2), two flexible transmission elements (5, 5a) fixed at one of their respective ends to the respective levers (1, 1a; 1', 1'a) at a certain distance from the pivot points of these levers and at their other ends to respective return springs (6, 6a), each of the flexible transmission elements (5, 5a) being connected to a drive shaft (4) by means of a free wheel device (30), characterised in that the said return springs (6, 6a) are constituted by two spirally wound leaves one of the respective ends of which is rigid with the second end of one of the said flexible transmission elements (5, 5a), whilst the other of these ends is rigid with the hub of a free wheel (30) mounted coaxially to the drive shaft (4). |
