1293. Scott, A. A. Jan. 26. Variable-speed toothed gearing such as is shown in Fig. 2 is controlled by a peripherally - acting angularly-adjustable cam 37, Figs. 3 and 4. A toothed wheel 4 slidable on a driving - shaft 3 carries a clutch member 5 adapted to engage, for direct driving, a member 15 on a driven sleeve 12. A countershaft 7 carries a wheel 6 meshing with the wheel 4, and other wheels 8, 9 meshing with wheels 10, 11, which turn separately but slide together loosely on the sleeve 12. The wheels 10, 11 have clutch members 13, 14 adapted to engage respectively with the member 15 and another member 16 on the sleeve 12, through which reduced forward speeds are alternatively effected. The wheels 10, 11 are operated together by a fork 21, Figs. 3 and 4, and the member 5 by a fork 18. The fork 18 is secured to a slidable bar 25, and the fork 21 to a sleeve 29 slidable on the bar 25. Lugs 30 on the bar 25 and sleeve 29 carry rollers 31, which are pulled by a spring 33 against the periphery of the cam 37, which is adjusted by means of a lever 36. The cam has a recess 40 for operating the fork 18, and a recess 41 and a raised portion 43 for operating the fork 21. A pawl 44 pivoted at 46 is held by a spring so that a rounded nose 49 engages one of a number of recesses 50 in the edge of a plate 38 so as to check the cam 37 in proper gear positions. An additional pawl 45 also pivoted at 46 has a square nose 48 adapted to engage the recesses 50 and lock the cam until the pawl is positively withdrawn.
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