GB757549A - A multi-speed gear change mechanism - Google Patents

Abstract

757,549. Variable-speed gearing. RAMBUSEK, H. March 25, 1954 [April 30, 1953], No. 8767/54. Class 80(2) Gearing giving six forward ratios comprises two friction clutches A, B for transmitting the drive from a driving shaft 10 and a common casing 12 to either a shaft 19 direct on a countershaft 25 through a hollow shaft 20 and gears 23, 24. Secured to shaft 19 is another gear 30 meshing with a gear 29 free on shaft 25 and adapted to be clutched to an output shaft 31 through a dog clutch 5. A sleeve 27 free on shaft 25 carries a gear 28 meshing with a gear 32 free on shaft 31 and is adapted to be clutched by dog clutch 1 to the gear 29 or by dog clutch 2 to the shaft 25. A further gear 26 secured to the shaft 25 meshes with a gear 33 free on shaft 31. Dog clutches 3 and 4 are adapted to clutch the gears 33, 32 respectively to the shaft 31. This arrangement of clutches allows the engagement of the dog clutches of a new speed whilst one speed is operative through one of the friction clutches A, B, this clutch then being disengaged whilst the other is engaged to bring in the new speed without any substantial interruption .of the drive. The clutches A, B are of the over-running type, having the inner plates carried on members 15 in screw-threaded engagement with sleeves 17, 18 secured to shafts 19 and 20 respectively, to facilitate this operation. The engagement of the dog clutches for a new speed is also facilitated by two friction synchronizing clutches 51 and 52, the inner plates of which are secured to shaft 25 whilst the outer plates are secured respectively to a gear 45 meshing with a gear 46 on shaft 19 and to gear 29. Alternate operation of these clutches effect the necessary synchronization of the gear parts and dog clutches for the next speed selection. Two reverse speeds corresponding to the first two forward speeds are obtained by a gear 50 on shaft 25 engaging a gear 51 on a shaft 52 which is clutchable at 6 to a free gear 53 in mesh with a gear 54 on a shaft 31, the clutch 6 being engaged instead of clutch 3. The actuation of the clutches A, B and the dog clutches 1-6 can be effected by a single camshaft which is rotated to select and engage any desired speed and may be operated by auxiliary power such as an electric motor or pneumatic means. The ratios of the gear are preferable graduated according to a geometrical progression.