A labour economizer which is designed based on the lever principle sets driving shaft built by a couple of pressure lever at motive force arm end of lever and sets driven shaft built by a couple of driving structural component at drag force arm end of lever. In the course of one cycle rotation of the driving and driven shafts, each sliding side rod can only push the driven shaft for one angle rotation so that the labour economizer will achieve the optimum effect of labour economizing when the rotary radius formed by the pressure lever and formed by the driving component is the same. To set it on the rickshaw, it will save mush more manpower than the rickshaw set with the economizer in existing technique under the same speed ratio. |