Consider two off set cams and between these two cams there is one follower.From the contact point of cam and follower, we continuously decrease redii of cam up to one point.We give minor decrease in redii. we decrease redii at 10:1 ratio. It means if the length of periphery from one point to other point is 10 cm than decrease of redii from one point to other point is 1 cm. For left side cam we decrease redii from right to left. I mean we decrease redii of left side cam in antclockwise direction. For right side cam we decrease redii from left to right. we decrease redii of right side cam in clockwise direction.Now we apply some vertical load or weight from follower to two cams.Tengential componant of this load helps the cams to rotate. Left side cam rotate in clockwise direction and right side cam rotate in anti clockwise direction. Because of minor decrease in redii of cams ,follower come little bit down in vertical direction. But the same time the load or weight helps cams to rotate on more length of periphery at some angle. We cam increase efficiency of rotating shaft. We can lift mass using less energy.To see figure pl visit http://energyefficiency.zoomshare.com Jigar Patel