Mechanism causing rotation by tensioning belt - acting on rollers in groove following Archimedes spiral contour

摘要

The mechanism comprises a shaft (6) carrying circular discs (1) and a core (2) with a spiral-contour groove (3) containing rollers (15). A belt (10) runs around a fixed roller (4) and the rollers (15), two ends of the belt being secured (8) to the ends of pivoted (14) levers. A screw mechanism (13) can be operated (11) to move the levers together, thus tensioning the belt (10) and causing the discs to rotate.