Patent GB-924446-A (GB)
Title: Gear change mechanism
IPC: F16D23/06
Filed: 1961-09-05
Abstract: 924,446. Securing clutch sleeves on shafts; positive clutches; change-speed gear and control. ADAM OPEL A.G. Sept. 5, 1961 [Sept. 13, 1960], No. 31887/61. Class 80 (2). Change-speed and reverse gearing for a motor car, of the type comprising a clutch sleeve 26 formed with internal splines 75 sliding on external splines 74 on a hub 18 secured to a driven gearshaft 13 and selectively meshed with clutch dogs 24, 23 on pinions 20, 15 to establish first and second ratios, the clutch sleeve also being formed with peripheral gear teeth 34 which can be meshed by a reverse idler when the sleeve is in its neutral position, has the sleeve restrained from sliding out of its mid-position during transmission of reverse torque by forming the external splines 74, Fig. 11, with shoulders 77, alternate circumferential slots 73 between the splines 74 having narrow and wide portions 73a, 73b. When reverse torque is being transmitted to the driven gear-shaft 13, the internal splines 75, Fig. 12, of the clutch sleeve 26 engage the shoulders 77 and hold the clutch sleeve in its midposition. The ends 75a, Figs. 12, 13, of the internal splines 75 are inclined as shown to form shoulders 76 which engage the clutch dogs 23, 24 on the first and second ratio pinions, the arrangement being such that, during transmission of torque in either of these forward ratios, the clutch sleeve 26 is restrained from sliding axially towards its mid-position. Establishment of either of the forward ratios is synchronized by balk-ring mechanisms (not described). The gearing shown comprises an input shaft 10, Fig. 1, a countershaft 27 and the driven gear-shaft 13, third ratio and direct drive being established by axially sliding a clutch sleeve 25. Selection and establishment of the various ratios is effected by a universally mounted and manually actuated lever 42, Fig. 2, connected to a slidable selector shaft 35. In the position shown, the selector shaft 35 is spring biased so that a finger 60 fast thereon engages a notch in a first and second ratio selector rod 46, while a cam surface 55b on a second finger 53 engages a recess in a third and top ratio selector rod 45. The arrangement is such that the selector shaft 35 can be turned one way or the other to slide the selector rod 46, for establishment of either first or second ratio through the usual fork &c., while the cam surface 55b locks the third-top ratio selector rod 45 in its neutral position. By sliding the selector shaft 35 axially to the right of Fig. 2, the finger 60 is disengaged from the first-second selector rod 46, which is instead held in its neutral position by a locking cam surface 62 associated with the finger 60. At the same time the finger 53 is engaged with a notched member 54 fast with the third-fourth ratio selector rod 45. On turning the selector shaft 35, the selector rod 45 is slidden to establish either third or direct drive in the gearing, while the cam surface 62 associated with the finger 60 locks the first-second selector rod 46. On further sliding the selector shaft 35 rightwards of Fig. 2, overcoming the bias of a restraining spring-urged plunger 59, a finger 64 fast with the finger 60 engages a spigot 67 on a lever coacting through a selector rod 47 and a selector fork with an axially slidable reverse idler. At the same time, the first-second ratio selector rod 46 continues to be locked in its neutral position by the cam surface 62, and a cam surface 55a on the selector finger 53 engages the recess on the third-top selector rod 45, also similarly locked in its neutral position, while the finger 53 is disengaged from the thirdtop selector rod. Thus the clutch sleeve 26 is locked in its mid-position, so that on turning the selector shaft 35, the selector rod 47 is slidden to mesh the reverse idler with the external teeth 34 on the clutch sleeve and also with a countershaft gear 31, for establishment of reverse.