Patent GB-423986-A (GB)
Title: Improvements in and relating to variable speed gearing
IPC: F16H63/16
Filed: 1934-07-10
Abstract: 423,986. Variable speed gearing. SEMERY, J. M. C., 112<bis>, Rue Cardinet, Paris. July 10, 1934, Nos. 20284 and 20285. Convention dates, July 13, 1933 and June 5, 1934. [Class 80 (ii)] Relates to a variable-speed gear of the kind in which a series of hollow pinions are independently rotatable in the casing and may be selectively connected by a sliding clutch to the driving shaft which passes through them. According to the invention the clutch is a freewheel clutch preferably of the kind comprising a drum having eccentric slopes to grip rollers. In the form shown in Fig. 1 gears 4, 5, 6 supported on sleeves in the casing in constant mesh with gears on a countershaft 7 are selectively operated by a ball-ratchet clutch 14 splined on the driving shaft 2. For neutral, the clutch engages a loose sleeve 17, which may, however, be slid to the right so as to drive the reverse gear pinion 20. In the modification shown in Fig. 4, the clutch 14 is connected through a sleeve 26 to an oppositely-directed ratchet clutch 27 which grips the next adjoining gear 5 or 6 in first or second speeds to give engine braking. The balls of the clutch 27 are spring- pressed to ensure instant engagement on overrunning. When the clutch 14 is inside the top gear pinion 6 the clutch 27 engages a loose sleeve 10<1> so that overrunning is possible. The low gear pinion 4 is clutched to the sleeve 8 by sliding the clutch 30 to the right and the reverse gear 29 by sliding clutch 30 to the left. In the position shown the sleeve 8 is free to give a neutral. Gear change may be effected by the engine-suction servo-device shown in Fig. 7. The clutches 14, 27 are moved by a piston 40 sliding in a cylinder 41 under the control of an engine-suction valve 42 and an air-inlet valve 43 simultaneously operated by a centrifugal governor 44 on the driven shaft 3. In the position shown, for first speed, the left-hand end of the cylinder 41 is connected to suction through the pipe 49 and the right-hand end to atmosphere through the pipe 54. As the speed of the driven shaft rises, the governor 44 brings the valve 42, to a position in which suction is applied through the pipe 50 to the right-hand side of the piston 40 while the left-hand side is open to atmosphere through the pipe 60, auxiliary valve 57, pipe 55 and valve 43. The piston 40 is thus moved to occupy a position between the branches 52, 53 of the pipe 50. For top speed, suction is applied through the pipe 51 and atmosphere through the pipe 56, so that the piston 40 moves to its extreme righthand position. The auxiliary valve 57 is then moved by the rod 58 and pivoted lever 59 to connect the pipes 61, 55, so that when the governor returns the valves 42, 43 to the second speed position the right-hand end of the cylinder 41 is connected to atmosphere through the pipe 55, thus permitting the piston 40 to return to its intermediate position. The speeds at which the gear-changes take place may be manually controlled by a lever 68 which can rotate a nut 67 to vary the distance between the governor flange 65 and the flange 64 which is connected through pivoted links to the valves 42, 43.