GB471458A - Improvements in and relating to change speed gearing - Google Patents

Abstract

471,458. Controlling change - speed gearing. FLEISCHEL, G. Dec. 9, 1936, No. 33875. Convention date, Dec. 9, 1935. [Class 80 (ii)] A two-speed planetary train is operated by a sliding annular brake 12, Fig. 1, which is slid axially by servo means and as it slides, disengages a direct-driving clutch 9, 10 and thereafter remains in braking engagement with the freed clutch part 9 to effect a geared drive. That is, springs 16 tend to hold in the solid drive clutch 9, 10 which is disengaged by servo action and a sun gear 7 is held so that an annulus 2 drives the carrier 4 of planets 6 and a driven shaft 3 at reduced speed. The servo means may be an annular piston 36b, Fig. 11, or it may be a set of cylinders 36, Fig. 1, energized by oil pumped at 13 when a slide valve 38 is depressed. Forms of double coned and of multiple-plate clutching and braking surfaces are described. As shown in Fig. 10, any number of two-speed units A, B, C may be compounded in series, their control valves a, b, c being depressed selectively by solenoids such as 88 and a manual selector switch 91. In an automatic transmission for a vehicle shown in Fig. 11, an enginedriven governor 107 throws a lever 111 over to the right against a contact 114 every time a step-up in the speed of the driven shaft D is to be made. A resisting plunger 115 causes the changes up and down to be made at different speeds. This change of contact of the lever 111 turns a suitable motor 116 stepwise up or down to shift a switch arm 91 into four positions, bringing in the four speeds derived from two two-speed units B, C according to the invention. There are solenoids in the valve unit c of the gear unit C and a similar one in the valve unit of the gear unit B admitting oil pumped at 92 to the left of annular pistons 36b &c. The oil-return pipe 40 has a raised loop at 95. The gear unit A shown is for reversing and it is operated by a manual switch 119. The engine clutch 98 is brought in automatically by centrifugal weights 99, and a one-way clutch 103 allows the engine to be used as a brake. In a modified arrangement shown in Fig. 12, the engine clutch 126 is electromagnetic and is engaged by the engine-driven governor 107 throwing a switch lever 130 to engage a contact 132. The same governor throws the speed switch lever 111 over right for a stepped change up, and allows the lever 111 to return left for a change down. These steps are effected by angular displacements of the armature of an electric motor 116 which turns a shaft 77 with selector cams 79, 80 for depressing the hydraulic valves b, c of the two forward-driving units B, C. The reverse unit A is operated by a turn of the motor 116 effected by a manual switch 119.