Belt drive pulley for small mechanisms - has springs between rim and hub and operates as slipping clutch

摘要

The shaft (1) carries a small pulley (2) driven by the belt (5) from the large pulley (4) mounted on the shaft (3). The pulley (4) has a hub (6) (6) surrounded by a rim (7) with an external groove (11) to accommodate the driving belt (5). Leaf springs (10) arranged to form a pentagon are fitted in the annulus formed between the hub (6) and rim (7) with the ends of the leat springs being force fit in the inner groove (8) of the rim (7). The tension in the leaf springs (10) maintains a constant tension in the belt (5) and compensates for thermal expansion. If the drive is overloaded, the mechanism is protected from damage by slip occuring between the surfaces of the springs (10) and the hub (6).