Anti-backlash drive system
AssigneeCargill Detroit Corporation
InventorsMark Saberton, Michael L. Trowbridge
Life of this patent
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Abstract
An anti-backlash rack and pinion drive system comprising a pair of spur gears on parallel shafts engaging a rack with countertorque preload imposed by a positive timing belt engaging a pair of pulleys respectively coupled to the shafts. Slack on one side and a resilient transverse load applied to the other side of the belt provides counterspur gear tooth pressure on the rack equal to the maximum drive load effected through reversible rotation of one of the shafts.
Claims9
Drive system for accurately positioning carrier drive means along a fixed linear path on a machine bed having a fixed linear rack comprising reversible rack and pinion gearing with drive means for anti-backlash operation, said system including a rigid carrier reciprocable on said machine bed, a pair of rack engaging pinion gears on parallel gear shafts mounted on said carrier having fixed spacing, a sprocket drive connection with each gear shaft, a positive sprocket coupling timing belt, said belt having a positive engagement with both sprockets to provide a driving belt side and a slack belt side, resilient means for imposing tensioning load on said driving side only of said belt with slack always maintained on said slack side to provide opposite rotational torque on said pair of gears during rack drive engagement, said torque being sufficient to maintain opposing gear/rack tooth engagement without backlash throughout translation of said carrier in either direction along said linear path.
Dependencies are inferred from the claim text.