High ratio speed reducer
AssigneePitney Bowes Inc.
InventorHugh St. L. Dannatt
Life of this patent
Estimating the term…
Abstract
A high ratio speed reducer comprising a rotatable input shaft operatively coupled to an output shaft which rotates at a reduced speed in response to rotation of the input shaft. An output sprocket is mounted on the output shaft for rotation therewith, the output sprocket having a circumferential perimeter including a number of teeth. A drive sprocket having a circumferential perimeter including a number of teeth differing by at least one tooth from the number of output sprocket teeth is rotatably mounted with respect to an eccentric end portion of the input shaft and orbits as the input shaft is rotated. Successive segments of the drive sprocket perimeter continuously move outside the output sprocket perimeter as the drive sprocket orbits to advance an endless double chain engaging both sprockets.
Claims8
A high ratio speed reducer comprising:
- rotatable input and output shafts having a common axis, said input shaft having an eccentric portion;
- an output sprocket mounted on said output shaft for rotation therewith, said output sprocket having a circumferential perimeter including a number of teeth;
- a drive sprocket having a circumferential perimeter including a number of teeth differing by at least one tooth from the number of output sprocket teeth, said drive sprocket being rotatably mounted with respect to said eccentric portion of said input shaft and orbiting with respect to said common axis as said input shaft is rotated, a segment of said drive sprocket perimeter being located outside said output sprocket perimeter as said drive sprocket orbits;
- an endless double chain engaging both sprockets, said chain having a driving length portion engaging said drive sprocket teeth on said segment while being disengaged from said teeth of said output sprocket, said chain having a driven length portion diametrically opposite said driving length portion engaging said output sprocket teeth and being disengaged from said drive sprocket teeth;
- and
- means for preventing turning of said drive sprocket as it orbits, including (i) a slide body attached to one side of said drive sprocket for movement therewith, said body including two parallel slide surfaces extending in parallel relation to said common axis of said input and output shafts;
- (ii) a housing including an elongate slot receiving said slide body, said elongate slot having two parallel slip surfaces engaging said slide surfaces of said slide body to permit reciprocal movement of said slide body in said slot in a first direction transverse to said common axis;
- and (iii) means permitting reciprocal movement of said housing in a second direction transverse to both said first direction and said common axis.
Dependencies are inferred from the claim text.