Patent GB-661405-A (GB)
Title: Improved method of and means for gear-shifting in high-power multiple drive units
IPC: F16H37/00
Filed: 1949-01-25
Abstract: 661,405. Variable-speed gearing. HONNORE, M. A. J., and ZENS, P. M. F. Jan. 25, 1949 [Jan. 28, 1948; Jan. 13, 1949], No. 2062/49 and 2063/49. Class 80 (ii). [Also in Group XXXI] In a multi-engined railway locomotive or other vehicle, each engine, such as the Diesel engine 9a, Fig. 8, drives its own or the same set of axles through a clutch 10a, a change-speed gear 7a, a free-wheel, a reversing gear and a reduction gear, the ratio between any two successive gears in any engine unit being smaller than the ratio of the maximum full-load speeds of that engine and the gear ratios being slightly different in the various gear boxes. Gear changes are effected successively and in sequence in the various gear boxes, each change being preceded and succeeded by disengagement and re-engagement of the corresponding clutch, so that during a gear change in one engine unit the tractive effort is maintained by the other units. The clutches and gears are actuated by compressed air drawn from a tank 13 under the control of valves operated from a central control desk. As shown in Fig. 8, the valves are operated by a number of hand levers 94 arranged in groups corresponding to the several engine units. Pivotal movement of the levers, along transverse slots 96, Fig. 6, in a selector plate 93, operates valves 43 or 44 controlling supply of compressed air to cylinders 16 of spring-loaded gear-changing pistons, while sliding movement of the levers 94 into or out of latching notches 99 at the various gear positions operates, through sliding grids 105 and levers 108, valves 48 controlling supply of compressed air to cylinder 50 of clutch-engaging pistons, the clutches being disengaged by springs. In each engine unit an electrically-operated valve 59 in series with switches 58 operated by the gear rods 28 cuts off the supply of compressed air through the pipe 47 to the corresponding clutch valve 48 unless the required gear is properly engaged. A further valve 54 in each pipe 47 is operable by a handle 55 so as to regulate the clutch engagement, while such regulation may also be effected directly by a pedal 53. An arm 63, loose on each clutchcontrol shaft 52 but frictionally driven between stops 69, 70, Fig. 12, by a washer fast on the shaft, is connected by an adjustable link 71 and a further link 75 to an arm 80 on the adjusting spindle 61 of the fuel-injection pump 12, the pin 74 between the two links being connected by a further link 76 to one arm 77 of a bell-crank lever, the other arm 78 of which is connected with the engine throttle lever. The arm 80 is connected to the link 75 by a slidable yoke pressed against a nut by a spring 83. Thus, whenever the clutch is disengaged, the lever 80 is moved against a stop 80a to bring the engine to idling speed, irrespective of the throttle setting, the lever 30 being restored to its former position when the clutch is re-engaged. As shown in Fig. 17b, for a two-engined locomotive, a single rotary disc valve 213 controls all the gear changes during one ro.tation of the valve, which is rotated through reducing gear 214 by a handle 218 the shaft of which carries a cam 242 which operates the clutch valves 244 and 245, the clutches in this case being engaged by springs and disengaged by the compressed air. An electrically-operated valve 231 in the supply pipe 230 to the valve 213 is operated so as to render the valve ineffective upon complete depression of a pedal 263 to close a switch 264, while, as before, an electrically-operated valve 254 in each unit acts to prevent clutch engagement unless the required gear is properly engaged. A valve 257 for modulating the engagement of either clutch is operated by partial depression of the pedal 263. Alternatively, a shaft provided with various cams for operating all the gear and clutch valves in the required sequence may be rotated by a hand wheel.