Motion-converting gearing

Claim 1

A motion-converting gearing comprising a drive shaft and a driven shaft and adapted to convert a constant rotation of said drive shaft into an intermittent rotation of said driven shaft, a substantially elliptic drive gear secured to said drive shaft, a substantially elliptic driven gear secured to said driven shaft, each of said gears having a toothed section and a toothless section connected to the beginning and end of said toothed section, said toothed sections adapted to interengage with each other for common rotation of both shafts, a roller support secured to said drive shaft, a pair of rollers rotatably mounted on said support and having axes within planes spaced at radial distances from the axis of said drive shaft, and a cam member secured to said driven shaft and having a first decelerating curved cam groove and a second accelerating curved cam groove at opposite sides of the central longitudinal axis of said cam member, each of said grooves having an open inner end near said driven shaft and another open outer end remote from said driven shaft and being respectively defined by first and second outer and inner guide walls, said first groove at its inner end adapted to receive said first roller and tO be guided by the same from the end of said toothed section of said driven gear near the axis of said driven shaft until it leaves the outer end of said first groove and for thereby decelerating the rotation of said cam member and driven shaft from said common rotation up to a stopped position at said outer end of said first groove, said second groove adapted to receive said second roller from said stopped position at said outer end of said second groove and to be guided by said second roller into said outer end and along said second groove to the beginning of said toothed section of said driven gear near the axis of said driven shaft until it leaves said inner end of said second groove and for thereby accelerating the rotation of said cam member and driven shaft from said stopped position to said common rotation, said first roller in said stopped position of said cam member and driven shaft being at least about to leave said outer end of said first groove, while at the same time said second roller is at least about to enter said outer end of said second groove, said inner walls of both grooves having a common cam-shaped end portion connecting the outer ends of said inner walls to each other and extending in said stopped position so far between and in engagement with both of said two rollers that said driven shaft while stopped will be positively locked for a period up to a larger than momentary part of each complete revolution of said drive shaft, said outer ends at least of said inner walls adjacent to said connecting end portion having a shape so that during said stopped and locked period said first roller when leaving said outer end of said first groove will engage with but not move said inner wall of said first groove, while said second roller when entering said outer end of said second groove will engage with but not move said inner wall of said second groove.