Patent GB-702840-A (GB)
Title: Improvements in or relating to variable speed transmission apparatus
Inventor: GATISS ALBERT LESLIE
IPC: F16H47/08
Filed: 1950-11-18
Abstract: 702,840. Change-speed gear. BROCKHOUSE ENGINEERING (SOUTHPORT). Ltd. Nov. 5, 1951 [Nov. 18, 1950], No. 28250/50: Class 80 (2) A three-element planetary train, which is driven through a hydrodynamic torque-converter of the usual overrun reactor type, Fig. 1 (not shown), and itself has a reaction sun 20, prevented from reverse rotation by a one-way detent 22 for reduced drive. and directly clutchable at 27 either to the impeller-sleeve 9 (as shown) or to the turbine, Fig. 8 (not shown) of the torqueconverter for a direct drive which is respectively of the split-torque or all-fluid type, comprises an input planet-carrier 17, fast to the turbine-shaft 16, and carrying intermeshed planets 18 which mesh respectively an output ring-gear 19 and the reaction sun 20. The ring 19 drives a gear-output shaft 38 through a torque-speed sensitive governor which may be either as described in Specification 639,735, or as described below and serves to operate a valve controlling the supply of pumped oil to and exhaust from a cylinder containing an annular piston 30 for automatically engaging the direct-drive clutch 27. A manual control valve may also be provided, as in Specification 702,839. The clutch supply line 47 may have a local exhaust valve as in Specification 702,838. To enforce a bi-directional reduced drive for engine braking, a linkage 89 can be manually operated to exhaust the direct-drive clutch 27 at 88 and supply oil pressure to a piston, Fig. 3 (not shown) for operating a simple lever to contact a brake-band 90 on the outer part 27 of the direct-drive clutch which is connected to the reaction sun 20 through a sleeve 21. The gear output shaft 38 drives a final output shaft 56, e.g. of a vehicle, through a reverse gear comprising input and output bevel side-wheels 53, 57 meshing planets on a carrier 55 having splined to it a forward-neutral-reverse dog clutch 59 to hold it stationary at 62 for reverse or to clutch it at 63 to the final output shaft 56 for forward drive. To avoid idle-drag from the torque-converter during shifts of the dog clutch 59, a rocking brake, which may be as described in Specification 365,998, is applied to the output ring 19 of the gear-train. This comprises a band 64 contracted around the output ring gear 19 by a piston 76, Fig. 5, through a lever 67 having a yielding fulcrum 69. Two forms of torque-speed governors for actuating the direct-drive clutch-valve are described. In Figs. 2, 5 and 6 centrifugal masses 32 fulcrum between projections 34, 35 inside a cylindrical extension 33 of the output ring 19, to act on an arm 37 fast on the gear output shaft 38, so that the passage of torque through the masses provides an inward force thereon, opposing centrifugal force, the resultant movement of the masses acting through a pin-and-slot connection 41 to screw an internally threaded sleeve 42 along a male thread 43 on the gear output shaft 38, the axial component of this movement operating the clutch control valve 31 (not shown), but which may be as described in Specification 702,839), through a fork 45. The torque-speed governor shown in Fig. 9 comprises centrifugal masses pivoted at 111 on the gear output shaft and driven by a pin-and-slot connection 109 with the output gear-ring 19, Fig. 2. Movement of the masses in response to antagonistic speed and torque conditions operates a diametral piston valve 114, controlling communication of liquid supply and exhaust passages in the, hollow output shaft, Fig. 8 (not shown) with the clutch chamber. Pressure oil for the clutch, brakes, converter and lubrication is supplied by vane pumps 81, 82 in a common housing 80 and driven respectively by the output impeller-sleeve 9 and output reverse-gear cage 55.