Multiple belt tension control mechanism

Claim 1

Mechanism for controlling the tension of the belts of a multiple V-belt drive comprising a first multiple V-groove drive pulley, a second multiple V-groove driven pulley, a plurality of V-belts, each of which is passed around and seated in respective grooves of both of said pulleys, said mechanism comprising: a lever pivotally mounted to a support element adjacent said belts, a walking beam pivotally connected to said lever by a fulcrum, said fulcrum being spaced from the pivotal mounting for the lever and located intermediately of the ends of the walking beam, a pressure sheave axis adjacent each end of the walking beam, said axes being parallel and spaced at selected distances on opposite sides of the walking beam-to-lever fulcrum, at least one pressure sheave journaled for rotation on each pressure sheave axis, the total number of pressure sheaves corresponding to the number of belts, said pressure sheaves being offset axially thereof by a distance equal to the lateral separation between adjacent belts, and positioned with one of the pressure sheaves in rolling relation with each of the belts, the distance from the fulcrum to each pressure sheave axis being inversely proportional to, (a) the number of pressure sheaves journaled on the respective axes, and (b) the desired pressure ratio of the sheaves journaled on each pressure sheave axis, and biasing means urging the lever in a direction, and with force of a magnitude, to exert selected, equal pressure of the pressure sheaves on their respective belts.