Patent GB-797156-A (GB)
Title: Improvements in or relating to change-speed transmission
IPC: F16H47/06
Filed: 1956-03-14
Abstract: 797,156. Change-speed gear. BORGWARNER CORPORATION. March 14,1956 [March 16, 1955], No. 7963/56. Class 80 (2). A change-speed gear on a vehicle, including an hydrodynamic torqueconverter 12 driving an output shaft 11 through disengageable countershaft gears 13, has a reversely acting one-way clutch 71 to transmit forward overrun torque from the output 11 through a sleeve 27 and the torque-converter to the input engineshaft 10, e.g. for push starting the engine in neutral; for one-to-one (approximately) engine-braking in an otherwise one-way second speed; and for causing the output shaft to drive the converter turbine at one-to-one during directdrive operation. Function summary.-The gear provides a two-way low and reverse, a second speed which is one-way drive and one-to-one overrun, and an all mechanical two-way direct-drive third, between which and starting second, shifts are automatic under control of an output-driven centrifugal governor 147, mechanically loaded by the usual accelerator pedal 167 which latter has an overtravel kickdown position. A valve 101 for releasing a normally engaged clutch 15 driving the countershaft gear is operated, for gear shift, mechanically by a pedal 121, and electrically by a switch 130 on a manual shift lever 128. Gear arrangement.-An input wheel 48 of the countershaft gear 13, driven from the input shaft 10 through the torque-converter, sleeve 27 and friction clutch 15, drives the first and reverse countershaft wheels 54, 55 directly and the second-speed wheel 57 through an invariable one-way clutch 58. Shifts between first and second main-shaft wheels 50, 49 are made by a manual synchromesh clutch 60, direct-drive being introduced by hydraulically engaging a front disc clutch 14, directly connecting input and output shafts 10, 11. Friction clutches.-A piston 40, which engages the countershaft-drive clutch 15 through a double-presser plate 46, has a free ball valve 47, which, under clutch-engaging fluid-pressure supplied at 45, closes a passage leading to within the clutch. The direct-drive clutch 14 is as described in Specification numbered 702,709. Fluid system components.-These are all installed in a plate 33 forming a dividing wall between the torque-converter and countershaft gear. They comprise a single inputdriven crescent gear pump 75 (which may be replaced by the existing engine lubricating pump); a simple spring-loaded relief valve 83; a torque-converter feed pressure regulator 93; the mechanically and electrically-operated valve 101 controlling the gear clutch 15 ; and a governor-operated valve 92 controlling the direct-drive clutch 14. Operation.-With the gear in neutral and the engine running the gear-driving clutch 15 is engaged through its normally-open valve 101 supplying regulated pressure 82, 90, to its feed line 102. At a predetermined vehicle speed, increased by accelerator depression (as described below), the output driven governor 147, through a lever 158, mechanically opens the high-speed valve 92 to supply regulated pressure 82 to engage the direct-drive clutch 14, whereupon the one-way second speed clutch 58 overruns. Governor.-The output shaft 11 drives an axially fixed sleeve 137, Fig. 11, in which is splined a shaft 142 carrying on splined collars 143, 144, the pivoted masses 147. Trunnions journalled on one collar 144 engage a bellcrank 158, an adjustable screw on one end of which directly acts on the stem 161 of the direct-drive clutch valve 92. A compression spring 149 closes in the masses, and a further closing spring 151 acts on the inner shaft 142 to bias the remote governor collar 143 against a casing stop 155 in opposition to a lever 165 162, operated by the accelerator pedal 167, depression of which latter thus increases the compression of both springs to raise the opening speed of the masses 147 from upshift at 16 m.p.h. with closed throttle to 36 m.p.h. with wide open throttle, together with a kickdown overtravel position reached against the resistance of a nose on the lever 162 raising a spring detent 169, raising the upshift speed to 64 m.p.h. To ensure disengagement of the direct-drive clutch 14 in manual low, a cam 171 on the low-speed shift-lever 64 positively closes the. direct-drive shift valve 92. Specification 702,709 is referred to.