GB530688A - Improvements in or relating to stopping and starting and variable speed devices - Google Patents

Abstract

530,688. Gearing for stopping and starting machinery ; clutches. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation.) May 17, 1939, No. 14676. [Class 80 (ii)] Apparatus for starting, stopping and driving a machine at any speed within limits at will, comprises driving and driven members 22, 32, mounted on a fixed shaft 16 and having engageable friction surfaces 26, 28. A braking surface 96 is supported by a bracket 12. The driven member 32 has a hub 40 on which a sleeve 42 can slide. The members 32, 42 rotate together. Axial movement of the sleeve 42 is controlled by a rod 70 which passes through the hollow shaft 16 and is connected through a lever 84 to a tension spring 92 and treadle rod 88. Weighted arms 48 pivoted to the sleeve 42 have cam surfaces 52 engageable with a radial face 54 on the driven member 32. A spring 56 tends to move the clutch surfaces into engagement. The spring 92 is stronger than the spring 56 so that when the treadle lever 88 is released the brake 96 holds the member 32 stationary. Upon depression of the treadle lever 88 the sleeve 42 is free to move to the right and the spring 56 moves the member 32 to engage the clutch surfaces 26, 28 and rotate the driven member 32. The weighted levers 48 are then subjected to centrifugal force and the cam surfaces 52 bear on the radial face 54. At a speed dependent upon the position of the rod 70 the cam surfaces 52 press on the face 54 and relieve the pressure between the friction surfaces 26, 28 to keep the speed of the driven member 32 constant.