GB548044A - Variable speed transmission mechanism - Google Patents

Abstract

548,044. Hydraulic couplings. CLEVELAND, F. J. (Windfields, Ltd.). Feb. 12, 1941, No. 1944. [Class 69 (ii)] [Also in Group XXIV] A variable speed gear which is automatic according to speed and torque embodies a fluid coupling of the F÷ttinger type and epicyclic gearing. As shown, the driving element of the fluid coupling is formed in a flywheel 1 on the driving shaft A. The coupling has two runners 2, 3. Runner 2 is connected by an overrunning clutch 4 to a shaft B. Runner 3 is connected to a sleeve D. The latter and shaft B have sun gears F, G, meshing with gears E2, E<SP>1</SP>, of compound planetary pinions E mounted in a carrier 11. A third gear E3 of the pinions E meshes with a sun H on a sleeve N integral with a spider 30. The carrier 11 is connected to a brake drum 10 by an over-running clutch 9. The driven shaft C is integral with a reverse planet carrier 23 having planet pinions I meshing with a sun gear K on the carrier 11 and a'toothed annulus J fixed to a brake drum 24. Between an extension 15 of the carrier 23 and the carrier 11 is a friction clutch having clutch plates 20, pressure plate 18 and an adjustable back plate 19 acted upon by springs 37. Adjustable retractor springs act on the pressure plate 18. Pivoted at 21 to the extension 15 are weighted levers 16, Fig. 2, and ends M of the spider 30 engage between bushings 34 carried in bores in the levers 16 adjacent the pivots 21. The levers 16 have slots 16<SP>1</SP> in which are fitted toggles 17 one arm of which acts on the pressure plate 18 and the other on the extension 15. In operation with both brake bands 32, 33, released, the gearing is in neutral. For forward driving band 32 is tightened which holds the carrier 11 through clutch 9. As the prime mover is speeded up the runner 2 is rotated and the shaft C is driven at low speed therefrom through clutch 4, gears G, El, E3, and members 30, M, 16, 21 and 23. Continued acceleration of the prime mover causes the second runner 3 to rotate at the same speed as the runner 2 and the drive is then from the sun F, the clutch 4 over-running. This gives the second speed ratio. As the speed increases the weighted levers 16 move outwardly against the torque at the spider 30 and the friction clutch is engaged by the toggles 17 straighteriing. A direct drive thus results. For reverse driving band 32 is released and band 33 is tightened. The carrier 11 thus revolves backwards around the sun H and the drive to the shaft C takes place through the sun K and planet carrier 23.