Patent GB-343988-A (GB)
Title: Improvements in or relating to variable speed power transmission
Inventor: HAYES FRANK ANDERSON
IPC: F16H61/662
Filed: 1929-09-02
Abstract: 343,988. Variablespeed gearing. HAYES, F. A., Middletown, New Jersey, U.S.A. Sept. 2, 1929, No. 26664. Convention date, May 7. [Class 80 (ii).] Variable-speed gearing for motor vehicles &c. comprises an epicyclic friction arrangement variable automatically by precession by the effort of the engine, which passes automatically into and out of clutch-engaged noiseless solid driving. Thus the only necessary controls on a car are the accelerator and the service brake, actuation of the latter opening a valve 92, Fig. 18, which throws out the hydraulic gear control and disconnects the drive. By operating " speed " valve 89 through a further manual control, the oil pressure may be varied, which has the effect of changing the speed of the engine at which the maximum solid driving will take place, the note of the engine being an audible indication of such speed. Fig. 22 is a diagram of a gearing unit or set. A roller 19 is connecting a torus disc 10 fast on engine shaft 12 to a loose torus disc 15. Schematically, the forward drives are taken from the carrier of the roller 19 and the reversed drive from disc 15. When a roller 19 is moved out of a radial line a a, Fig. 8, precession comes in, that is, the roller runs on spiral tracks on the discs until a new position of equilibrium at a new speed is reached. The characteristic of this unit is that the axis n, n Fig. 22, of the trunnions 24, Fig. 8, of the yoke 22 of the roller 19 is inclined at a permanent angle to the planes of the discs. The effect is that when equilibrium is disturbed by a control member such as piston 95, Fig. 18, precession goes on automatically until a definite position is reached, that shown in Fig. 22, with the axis p p of the roller intersecting the axis m m of the gearing. The gear-control piston 95 thus remains in its new position, and serves as a valve to bring in the clutch 78, Fig. 18, for solid driving, at the proper time. This gear unit is torque-responsive, that is, the force required to push the yoke 22, Fig. 8, to one side is proportional to the load, and by using a spring the unit would be automatic. In the realization shown in Fig. 1, twin-gear sets are used with end discs 10, 11 splined on engine shaft 12 and pressed towards a loose double disc 15 by a spring 12a strong enough to prevent slipping and wear. The carriers of the rollers 19, 50 of the two sets are connected by a loose sleeve 13a shown schematically in Fig. 24. The load of driven shaft 63 is applied at 161 to rockers 54 which serve to displace the rollers 50 as in Fig. 8. The arbitrary control, which is always being balanced against the load control, is applied to the rollers 19 and is indicated by wedge 162. Since the torus surfaces rotate together in pairs, and the spiders 25, 55 of the two sets also rotate together, the rollers 19, 50 of the two sets must precess in unison for the same speed ratio, anything else being impossible. Also, the load is applied to rockers 54, and each rocker is a lever dimensioned so as to render equal the parts of the load placed upon the rollers 50 directly, and upon the rollers 19 through the spider 55, sleeve 13a, and spider 25. This explains why the arbitrary control can be applied to one set by a slider 46, Figs. 1 and 18, while the load is taken on a floating equalizer ring 56, Figs. 1 and 9, of the other set. The yokes of the rollers of both trains are supported on rockers with a slight inclination as explained with reference to Fig. 22. The second set, shown in Fig. 9, shows the equalizer load-carrying ring 56. The first set, shown in Fig. 2, is modified for connection with control slider 46, Fig. 1. A cam connection at 40 between elastic drums 37, 39 produces a relative turning of a central equalizer ring 35. The ring 35 is engaged by an arm 34 extending from each rocker 28, the rockers being pivoted at 27 to spider 25. Thus control is applied to rollers 19 through slider 46 from piston 95, Fig. 18. For all the geared forward drives, the abutment disc 15, Fig. 1, is held against rotation by a brake 72 to which it is connected through drum 71 and splined sliding clutch drum 67. The roller carriers are connected through clutch drum 75 and splines 76 to load shaft 63. When the speed of the car rises suf-' ficiently, brake 72 is released and clutch 78 applied for solid driving by the parts shown in Fig. 18. With the car standing and engine idling, pump 85 is driving oil ineffectively past "speed" valve 89, which is set for the purpose. To start the car, the driver speeds up the engine, whereby oil overflowing " speed " valve passes by pipe 91 to valve 115, which it opens, then into cylinder 108, pressing piston 106 to the right and applying brake 72 in effect to disc 15. The car starts off in lowest gear and the " get-away " may be made rapid as well as silent in the following manner. Oil banking up in pipe 91 forces valve 135 to the left and passes to speed control cylinder 96 in which piston 95 is then held at left by a spring and by torque reaction. Sufficient engine speed thrusts piston 95 and slider 46, Fig. 1, to the right, precessing the gear rollers and so accelerating rapidly to the capacity of the engine. Further speeding-up of engine brings the parts to the position shown, when piston 95 acting as a valve for the solid drive has allowed oil to pass through pipe 98 to close valve 115 and open valve 116. This closing has the effect of releasing brake 72, and the opening, by admitting oil to the right of a piston 106a, has the effect, through means 123, of applying the clutch 78 to drum 71, so that the gearing turns solid silently at highest speed. By adjusting " apeed " valve 89, the speed of the engine and therefore of the car at which solid driving takes place is varied. Piston 95 remains to the right and rollers are in high-gear position. On increased torque or reduced throttle opening, engine speed and oil pressure fall, and piston 95 moved by torque reaction cuts pipe 98 off from pressure and opens it to exhaust pipe 96a. Valves 116 and 115 rise, with the'effect that the clutch 78 is opened and brake 72 closed, restoring the automatic geared drive. The arrangement prevents disc 15 from ever being free to disconnect the drive. To drive reversely from rest, reverse shift rod 68 is moved manually to the left of Figs. 1 and 18. The planet carriers are connected through clutch ring 26 and drum 67 to drum 71, and middle disc 15 is connected through clutch drum 75 to load shaft 63. At the same time, valves 128 and 132 are operated. These have the effect of rendering inoperative both the detent action on drum 71 and the speed-control cylinder 96 ; the car is started in reverse exactly as in forward driving.