Stairclimber with a safety speed changing device

Claim 1

A stairclimber with a safety speed changing device comprising: a base; a handle frame vertically mounted on said base; a support vertically mounted between a gauge board and said base; a front bracket fixed on said base and spaced apart from said support; a rear bracket mounted on said base and disposed rearwardly of said front bracket; a motor having a variable speed V-pulley and slideably mounted on said rear bracket; a transmission mechanism fixedly mounted on the upper side of said front bracket and provided with a pulley connected to said variable speed V-pulley of said motor via a belt, and a linkage pivotally connected with an oscillating rod having a pair of pedals, said oscillating rod having a rear end which is in turn pivoted on two sides of said rear bracket; and a speed changing mechanism having a rotating handle disposed on upper half of said support to control an upper gear which in turn drives a lower gear via a chain, said lower gear connected to a universal joint connected with an axle having male threads and a stop collar at the end so that the axle may be engaged with a sleeve with female threads, said sleeve being formed at the top with a groove adapted to receive a stop member on the rear bracket, whereby said sleeve is moved rearwardly to push said motor and thereby change the exercising speed via the variable speed V-pulley.