Patent ID: 7335137

Claim:
A driving system for a magnetic resistance exerciser, the driving system comprising: a support member having a through hole defined therethrough and a plurality of positioning holes defined beside the through hole; a link having a shaft extending perpendicularly from a mediate portion thereof and an extension perpendicularly extending from each of two ends of the link; a fixed wheel fixedly connected to the support member and having a first central hole defined therethrough, a belt groove defined in an outer periphery of the fixed wheel; first and second rotatable wheels, each having a through hole defined in a center thereof, a first groove defined in an outer periphery thereof, an extension portion extending from a side of each rotatable wheel and a second groove defined in the extension portion, and a weight wheel having a second central hole and an extension portion extending from a side of the weight wheel, a third groove defined in the extension portion of the weight wheel, the shaft rotatably extending through the first central hole and the second central hole, a crank connected to each end of the shaft, one of the extensions of the link rotatably extending through the through hole of the first rotatable wheel and the other extension of the link rotatably extending through the through hole of the second rotatable wheel, a first belt engaged with the belt groove of the fixed wheel and the second groove of the extension portion of the first rotatable wheel, a second belt engaged with the first groove of the first rotatable wheel and the second groove of the extension portion of the second rotatable wheel, and a third belt engaged with the first groove of the second rotatable wheel and the third groove of the extension portion of the weight wheel.