Patent GB-277574-A (GB)
Title: Improvements in or relating to variable speed mechanism
IPC: F16H3/04
Filed: 1927-04-20
Abstract: 277,574. Ahlm, C. E. r. April 20, 1927. Variable-speed gearing comprises a plurality of internal-external constant-mesh non-epicyclic gear pairs as indicated in Fig. 7, with connections for gearing up, for gearing down, and for a oneto-one drive, alternatively. The invention is described as an auxiliary three-speed gear upon a Ford vehicle. 2, Fig. 1, being the rear axle housing, the propeller shaft 10, Fig. 2, passing within torque tube 6. In line with the driving-shaft 10 are an intermediate shaft 15 and a driven shaft 11. Splined upon enlarged ends 17, 21 of the shafts 10, 11 are sliding clutch sleeves 16, 20 which may be engaged, as shown, with clutch heads 19, 22, respectively, upon the two ends of the shaft 15 to yield the one-to-one drive. A gear sleeve 31 turning freely in fixed eccentric bearings 32 carries internal teeth 35 meshing with an external pinion 36 fast on the shaft 15 and carries also external teeth 30 meshing with internal teeth 27 upon a loose member 25 concentric with the shafts. When the clutch sleeve 16 is slid to the left to connect the shaft 10 to the member 25 through clutch teeth 28, an overdrive results through train 27, 30, 35, 56, shaft 15, and clutch 22, 20. The gear sleeve 31 carries external gear teeth 37 meshing with internal teeth 38 on a loose member 39 concentric with the shafts. If the clutch sleeve 16 is restored to the position shown, and clutch sleeve is moved to the right to connect the shaft 11 to the member 39 through clutch teeth 42, an under-drive results through clutch 16, 19, shaft 15, pair 36, 35, sleeve 31, and pair 37, 38. A fourth speed is possible when the sleeves 16, 20 are both moved inwards from the position shown, in which a gearing-up pair works against a gearing-down pair, but this speed is not used in the adaptation shown, which comprises a control lever 68 which brings in the three ratios by a straight-through motion imparted to a link 70. The sleeve 16 is connected by a rod 55, Fig. 1, to a head 85 which has horizontal and inclined slots 88, 89, Fig. 4. The sleeve 20 is connected through a rod 56 to a head 80 which has horizontal and inclined slots 81, 82. In the direct-drive position shown, the lever 68 is in mid position. and a pin 74 upon the rod 70 lies in both inclined slots 89, 82. When the rod 70 is moved to the left, the pin 74, Fig. 4, rides down the incline and then carries head 85 with it, sliding idly in the slot 81. When the rod 70 is moved to the right from mid position, it rides up the incline and carries headr 80 with it, sliding idly in the slot 88. The lever 68 thus operates the sleeves 16, 20 selectively while moving continuously. The rod 56 or both rods 56, 55 may be connected to its clutch sleeve through a change-facilitating device comprising springs 57, Fig. 2, and spring cams 61, 63, Fig. 1, as described in Specification 265,881. The gear casing is in three parts 1, 4, 3. Fig. 1, between which oil can pass freely. The toothed gearing is lubricated by an oil scoop 45, Fig. 2, on the eccentric sleeve 31, which dips into oil and circulates it.