The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1976
Filed:
Dec. 06, 1974
Michel A Pierrat, Andover, MA (US);
Compudrive Corporation, Medford, MA (US);
Abstract
A compact high-torque mechanical speed changer, which offers a very wide range of output speeds in different angular directions through selections from sets of fully-interchangeable planet and sun gear combinations, and in which one predetermined counterweighting unit provides matching for the eccentricities associated with all the planet gears of such sets, comprises two sets of planet and sun gear combinations each having a one-tooth difference in numbers of effective teeth, the two externally-toothed planet gears being coupled together angularly and being mounted for eccentric rotation relative to a supporting input crankshaft, while the associated internally-toothed sun gears are respectively fixed with the changer housing and with an output member rotatable collinearly with the input shaft. Planet-gear teeth or lobes are of epitrochoid curvature, and all of the planet gears of such sets are of the same diameter; concomitantly, the companion sun gears, which are preferably of the type involving discrete roller-pin teeth rather than continuous-curvature teeth, are of the same diameter and only the number of such rollers varies from set to set. In other dimensional respects the gear sets are substantially identical and can therefore be interchanged to effect different ratios and directional senses of input to output speeds. A counterweight offsets the input-shaft and planet-gear eccentricities, and serves any selected planet gears from such sets. The changer housing and interior mountings for gear combinations accommodate assembly of the sets, as desired, to yield various speeds and directions of output.