GB176355A - Improvements in and relating to change-speed gears - Google Patents

Abstract

176,355. Williams, E. R. March 7, 1921, [Convention date]. Variable-speed toothed gearing of the countershaft type, suitable for motor-vehicles, is modified by the use of subsidiary gear pairs to facilitate the engagement of teeth in changing speed, the subsidiary gearing being operated by friction clutches in pairs. The countershaft 4, Fig. 2, constantly driven by a pair of wheels 5, 6 from a driving-shaft 1 carries fixed gears 9, 8, 10. A gear 11 slidable on splines on a driven shaft 3 has a clutch face 7 which is engaged with a like face 7' on the gear 5 for directdriving. For second speed, the gear 11 engages the gear 9. A second sliding gear 12 engages the gear 8 for third speed, or an idler in mesh with the gear 10 for reversed driving. Subsidiary gears 22, 23, 24, 25 corresponding respectively to these three speeds and to reversed driving are secured to an extension 21 of the shaft 4. These mesh with gears 27 - - 30 loose upon the shaft 3 and adapted to be connected thereto by friction clutches 32 - - 35 movable in pairs. If, say, the pair 8, 12 is to be intermeshed, the gear 29 is clutched to its shaft long enough to bring the speed of the teeth of the gear 12 to near equality with that of the teeth 8. After engagement, the gear 29 is declutched. Further to facilitate engagement, the shaft section 21 may be driven from the shaft 4 or from the shaft 1 through the yielding coupling 64, 65, Fig. 8. The gears 11, 12 are operated by forks'secured to telescoping -rods 13, 14, Fig. 1, which are operated from a suitable selective control through links 19, 20. The friction clutch pairs are operated in unison with the elements 11, 12 through forks 40, 41 pivoted upon fixed pins 42, Fig. 5, and articulated to telescoping rods 43, 44, Figs. 1, 3, and.4. Collars 51 secured to the rods 43, 44 are connected through springs 55 to cylinders 50, which are adapted to slide and are connected by bridge levers 48, 49 to recessed collars 46, 47 upon the main selector rods 13, 14. Springs 56 keep these bridge levers in position so that when one of the rods 13, 14 begins to move, the corresponding friction clutch is gradually brought into action. As the movement of the rod 13 or 14 nears its end, the lever 48 or 49 strikes a fixed cam 57 so as to become disengaged from the rod 13 or 14, which moves on alone to engage the main gear. The springs 55 assert themselves and the friction clutch and subsidiary gear pair are thrown out. An arrangement with the friction clutches on the counter-shaft is described, but they may be on both shafts.