Patent GB-480858-A (GB)
Title: Improvements in hydraulic torque converters
IPC: F16H61/56
Filed: 1936-07-31
Abstract: 480,858. Hydro-mechanical variable-speed gearing. DODGE, A. Y. July 31, 1936, Nos. 21243 and 21244.. Convention dates, Aug. 2, 1935 and Jan. 4, 1936. [Class 80 (ii)] [Also in Group XXIX] In a hydraulic torque converter comprising an impeller, a reaction member and a turbine, the impeller includes pivoted vanes at the outlet end thereof, said vanes being urged in one direction by the liquid reaction and in the opposite direction by means responsive to the impeller speed. The Specification as open to inspection under Sect. 91 comprises also, Fig. 1 (Cancelled), a transmission system for vehicles in which the engine shaft 1 drives, through a friction clutch 4, the driving shaft 12 of a torque converter 16 constructed as above and followed by epicyclic gearing which comprises a sun pinion 18, two concentric series of planet gears mounted in a carreir 32 and a ring gear 34; the sun pinion 18 is slidably splined on the driving shaft 12, a spring detent 44 being provided for holding it in various adjusted positions ; the whole gear-set is moved axially by a shift fork 46 and sleeve 48, the latter being splined to a sleeve 50 rigid with the output shaft 52 and engaging the planet carrier 32 by a synchronizing contact. Sleeve 50 carries dog-clutches 54, 56 ; the planet carrier 32 carries clutches 36, 38 ; the ring-gear 34 carries clutches 40, 42 ; the turbine sleeve 20, 22 of the torque converter carries clutch 24, backward rotation being prevented by a free-wheel 26, a stationary sleeve 28 also carrying clutch 30. Various drives are effected by moving the gear-set to engage variousclutches as follows. In the " NEUTRAL " position shown, no drive is transmitted. In the " REVERSE " position, clutch 30 is engaged with 40 whereby the ring gear 34 is held stationary, and clutch 38 with 54 whereby the planet carrier 32 is connected to output shaft 52 ; a purely mechanical fixed ratio reduced-speed reverse is thus obtained. In the " FORWARD " position, clutch 36 is engaged with 24 whereby the planet carrier 32 is connected to the turbine shaft 20, 22, and clutch 42 with 54 whereby the ring gear 34 is connected to the output shaft 52 ; the torque converter and epicyclic gear are then in " branched " connection ; since the reverse rotation of the turbine shaft and therefore of the planet-carrier is prevented at a varying ratio and eventually, when the turbine attains a speed equal to that of the pump, a one-to-one solid drive in the epicyclic gearing is automatically obtained. In the " MANUAL HIGH " position, clutch 38 is engaged with 56 and clutch 42 with 54 whereby both the planet-carrier 32 and ring-gear 34, are connected to the output shaft 52, and a purely mechanical one-to-one drive through the locked epicyclic gearing is obtained. In the " EMERGENCY LOW " position, clutch 36 is engaged with 30 whereby the planetcarrier 32 is held stationary, and clutch 42 with 54 whereby the ring-gear 34 is connected to the output shaft 52; a purely mechanical fixed ratio reduced-speed forward is thus obtained, which is useful for using the engine as a brake when descending steep hills. For connecting the driving shaft 12 directly with the output shaft 52, thereby cutting out the hydraulic-mechanical transmission, keys 58 working in slots in the sleeve 50 connected to said shaft 52 can be moved radially inwardly to engage grooves in said shaft 12, this being effected by a cam sleeve 60 movable axially against a spring 62, either manually by rock shaft 64, or automatically at a predetermined speed of the output shaft 52 by centrifugal weights 66 pivoted thereon and provided with a snap-action spring 68. The keys are arranged and shaped as shown in Fig. 2 (Cancelled). As shown in Figs. 1 (Cancelled) and 13 (Cancelled), rotation of the mechanical gearing in the housing 112 causes liquid contained in the latter to be forced through port 166 into a tank 164, building up therein a pressure which forces liquid through passage 170 and holes 172 to the torque converter. Bleed ports 168 permit escape of entrapped air and a limited circulation through the gear box. The interior of the gear box 112 communicates through pipe 180 with a condenser 176, having air-passages 178 adjustable spring-loaded bleed valve 184 and a return pipe 182 to the gear box. To reduce vaporization and to maintain a feed pressure, the gear box is maintained under pressure, as by connecting it by pipe 186 with the exhaust manifold 188 of the internal-combustion driving engine or with an engine-driven pump. In a modification, Fig. 14 (Cancelled), an " optional over-drive " is provided. The turbine sleeve 220, 222 carries subsidiary planet gears 223 engaging with a fixed sun pinion 225 and with a ring-gear 227 carrying a clutch 229. The NEUTRAL," "REVERSE," " FORWARD " and " EMERGENCY LOW positions are as described with reference to Fig. 1 (Cancelled). In " OVERDRIVE " position, clutch 236 is engaged with 229 whereby the main planetcarrier 232 is connected to the ring-gear 227 and, owing to the fixed ratio speed-increasing action of the subsidiary epicyclic gear, is driven faster than the turbine shaft 220, 222. This arrangement is useful where the back-axle ratio is suitable for traffic and hills when employing a direct drive between engine and propeller shaft, the over-drive being used for fast running on the flat. The subsidiary ring-gear 227 can be held stationary by inward radial movements of keys 231 effected by axial movement of a cam-sleeve 233 by means of a manually controlled rock-shaft 235 ; the turbine shaft 220, 222 is thus prevented from rotating, so exerting a hydraulic braking effect on the impeller of the converter and thus on the driving shaft 212, so that braking of the road-wheels is effected. In a modification, Fig. 15 (Cancelled), an " optional under-drive " is provided. The turbine sleeve 320, 322 carries a subsidiary ring-gear 327 ; planet wheels 323 are carried on a member 337 having clutch 324; the sunwheel 325 is prevented from reverse rotation by a free-wheel 339 arranged between it and the fixed sleeve 328 which carries a clutch 330. The " NEUTRAL," " REVERSE," " MANUAL HIGH" and " EMERGENCY LOW " positions are as described with reference to Fig. 1 (Cancelled). In the " FORWARD " position, clutch 342 is engaged with 354 whereby the main ring-gear 334 is connected to output shaft 352, and clutch 336 is engaged with 324, whereby the turbine sleeve 320, 322 drives, through the subsidiary epicyclic 327, 323, 325, the main planet-carrier 332 at a reduced speed ; shaft 335 journalled in fixed sleeve 328 can be rocked to move camming sleeve 333 axially, thus moving keys 331 radially inwardly to lock the planet-carrier 337 to the turbine sleeve 322, whereby the subsidiary epicyclic is rendered solid, and the main planet-carrier 332 is driven at the same speed as the turbine sleeve 320, 322. The under-drive is useful for use for traffic and hills where the back-axle ratio is suitable for fast running on the flat when employing a direct drive between engine and propeller shaft. By means of a lever 345 a key 343 mounted in the fixed sleeve 328 can be caused to engage teeth 341 on the turbine sleeve 322, whereby the latter is held stationary ; the turbine being thus fixed against rotation exerts a hydraulic braking effect on the impeller of the converter and thus on the driving shaft 12, so that braking of the road-wheels is effected. The above subject-matter does not appear in the Specification as accepted.