GB707483A - Improvements in or relating to infinitely variable speed gears - Google Patents

Abstract

707,483. Expanding-pulley gear. CARTER BROS. (ROCHDALE), Ltd., and DEAN, F. Sept: 22, 1952 [Dec. 28, 1951], No. 30264/51. Class 80 (2) The two flanges 3, 5 of a driving and/or driven expanding V-belt pulley are simultaneously axially adjusted in opposite, directions, whilst maintaining constant belt-plane and tension, by relative bodily movement linear or angular with respect to a straight bar 12 having divergent external cam surfaces, In Fig 2 the variable driving pulley is carried on the shaft 1 of a motor 2 which, to vary the effective pulleydiameter, is traversed in dovetailed base-guides 9 parallel to the belt 10 by an adjustable-screw 35, to cause blocks 16, 22, supporting the respective pulley-flanges 5, 3 through ball or selfaligning roller bearings, Fig. 1 (not shown), to ride along a slot in the cam-bar 12, which is carried on a fixed pillar 11 adjustable by a screw 37 parallel to the belt for initial tensioning. The pulley-flanges may be spring-loaded on to the cam-bar 12, which latter may have dovetailed guides for positive separation of the pulley flanges. The axis and diameter of the driven pulley are invariable. In Fig. 7, not shown, a variable output pulley, rotating on a fixed axis, is adjusted by transverse movement of a doublesided cam-bar acting like that 12 shown, secured to the motor which is moved bodily as before, with an invariable input pulley. In Fig. 8, not shown, the axes of both pulleys are fixed and the diameters of both are simultaneously oppositely adjusted by transverse movement of two double cam-bars such as 12, secured together at their wider ends. In Fig. 9 (not shown), more nearly constant belt tension is produced by a cam-bar having curved sides, each contacted at two spaced points by followers pivoted to the flange-thrusting blocks. According to the Provisional Specification the motor may pivot in an arcuate path, the cam-bar being correspondingly curved.