CRANK DRIVE WITH A DEVICE FOR PERIODIC CHANGES TO THE LENGTH OF THE EFFECTIVE LEVER THEREOF

摘要

A crank drive (10; 110) is disclosed, comprising a device for periodic changes to the length of the effective lever thereof, comprising: a force coupling device (11; 12), at least one crank (20; 120) with a first free end (21; 121) and a second end (22; 122), a shaft (30; 130), mounted to be able to rotate on a shaft bearing (31; 131) to which the force is transmitted by the crank (20; 120),a ring gear (40; 140), a planet gear (50; 150) and a first bearing device (60; 61; 160), which supports the planet gear (50; 150) in permanent engagement with the ring gear (40; 140), either the crank (20) in the region of the second end (22) being fixed to the shaft (30), the ring gear (40) in the region of the first end (21) of the crank (20) begin fixed or fixable to the crank (20) and the planet gear (50) being fixed to the force coupling device (11; 12) or the ring gear (140) being fixed with relation to the shaft bearing (131), the crank (120) being fixed to the planet gear (150) and the force coupling device (12) mounted on the crank (120), preferably such as to rotate. A crank drive is thus achieved wherein the length of the effective lever changes independently without intervention of the user and matches the individual requirements of the user whilst also guaranteeing a reliable long-life version of the crank drive.