GB439948A - Improvements in variable-speed gear selecting and shifting mechanism - Google Patents

Abstract

439,948. Variable-speed gearing. JONES & LAMSON MACHINE CO., Springfield, Vermont, U.S.A.-(Assignees of Twamley, W. E. ; Charlestown, Vermont, U.S.A.) May 14, 1934, No. 14553. Convention date, May 15, 1933. [Class 80 (ii)] A selector-bar 75 carries a number of selector-elements 90, 91, 92, each of which comprises a number of raised surfaces 95a, 95b, 95c, Fig. 9, of different heights, which surfaces enter between, and define the transverse position of spaced working faces 70 on shifter-rings 50, 51, 52, which rock about fixed axes 53 to operate levers 30, 37, 41, for shifting the three sliding pinions of a twelve-speed gear in a machine-tool. Selection is effected by turning the bar 75 whilst it is in an axially retracted position, the bar being then pushed back so that the faces 70 ride up the bevelled ends of the raised surfaces to introduce and lock the selected speed. The selector-bar 75 is moved axially and turned by movements, respectively in planes at right-angles, of a lever 102, Fig. 3, pivoted transversely to a rotatable bushing 78, slidably keyed to the bar 75, the lever having also a transverse pin 106 engaging a groove in the bar, the bushing and bar being locked by spring-loaded balls. A pointer on the bushing 78 co-operates with a fixed indicating-plate 121. The change-speed gear comprises a driving shaft 2, driven through clutches 9 or 10 by forward and reversely rotating driving wheels 7, 8 loose on the shaft. A first intermediate shaft 3 is driven at two speeds through a sliding pair 12 on the driving shaft 2, whilst a second intermediate shaft 4 is driven at three speeds from the first intermediate shaft 3, by means of a sliding pair 20, which can be meshed with any of wheels 16, 19, 17, the first two of which are secured to the shaft 3, whilst the wheel 17 is loose thereon and is of the same size as the fast wheel 19, but is driven at a different speed through a subsidiary countershaft 3a, having wheels meshing with the fast wheel 19 and a loose wheel 18, secured to the wheel 17. The second intermediate shaft 4 drives the final driven shaft 5 at two speeds, through a sliding pair 25, which has an intermediate neutral position. The operating handle 102 may control also starting, stopping, and reversing.