Patent GB-1051410-A (GB)
IPC: F16H3/00
Abstract: 1,051,410. Change-speed gear and control. BELORUSSKY POLITEKHNICHESKY INSTITUTE. July 14, 1964, No. 28918/64. Heading F2D. To provide for engine braking of a gasturbine powered motor car &c., gearing having a double input clutch and comprising a simple planet train with a countershaft train is provided also with a reverse train. A gas-turbine powered double clutch 81, 83 has friction discs S, engaged to drive through a shaft 4 to the sun gear 30 of a planetary train having its ring gear 29 stationed by engagement of a synchromesh positive brake 22, 25, thus establishing first speed through planet pinions 31 and a carrier 33 to an output shaft 21. Second speed is established by disengaging the discs S 1 and instead engaging the discs S 2 to transmit drive through gears 6, 7 to a countershaft 8, and thence through a synchromesh clutch 9, 13 to gears 19, 20 and the output shaft 21. Third speed is established by disengaging the brake 25 and instead engaging a synchromesh clutch 22, 26 to lock-up the planet gear, disengaging the clutch discs S 2  and re-engaging the clutch discs S 1 . Reverse is established through the clutch discs S 2 and gear train &c. 5, 6, 7 by disengaging the clutch 9, 13 and instead engaging a synchromesh clutch 9, 12 to drive through a gear 14 meshing a reversing idler 15, in turn meshing a gear 17 fast on the shaft 4, and thence through the planet gear, which has its ring gear stationed by engagement of the brake 22, 25 to give a step-down drive to the output shaft 21. To obtain engine braking of the car by the gas turbine when either first or third speeds are established, the clutch 9, 12 is engaged to introduce the reversing train 15 &c. into the power path, and following disengagement of the clutch discs S 1 ,the clutch discs S 2 are engaged. A transmission shaft brake 35 also is provided. Control.-A gear-shift lever 56, Fig. 2 (not shown), which rocks a two-armed lever 46 and alternatively opens and closes two valves 44, 45, causes admission of compressed air to one or other end of a servo 36 containing two free pistons 37, 38 coacting with a piston rod 39 actuating the double clutch S 1 ,S 2 .Whichever valve 44, 45 is closed to the compressed air source is instead opened to a vent pipe containing a needle valve 53 controlled by the position of the gas-turbine accelerator pedal 55. Throttled ports 52 restrict egress of air to exhaust from the servo 36. The double clutch S 1 ,S 2 incorporates over-centre diaphragm springs. On admission of compressed air to the servo 36, either the piston 37 or the piston 38 coacts with the piston rod 39 and provides a substantial initial force to overcome the resistance of the clutch diaphragm springs. As the latter go over-centre, the piston rod 39 disengages from the operative piston 37 or 38, which is held by a stop 42, and engages with the other piston 38 or 37, which acts as a damper, forcing air out through the restricted port 52 and through the needle valve 53, to give cushioned engagement of the clutch S 1 or S 2 . Switches 75, 76 control lamps 73, 74 indicating which clutch S 1 ,S 2 is engaged. The depending end 47 of the gearshift lever 56, which engages the valve control lever 46, is also engageable with slots in the hubs 65, 66 of gear strikers 59, 60, controlling the clutch sleeves 9, 22. The striker hubs 65, 66 are fast on rails 61, 62 retained in desired positions by spring biased detents 63, and provided with the usual interlocking drift pin 64, Fig. 4 (not shown). The end of the lever 46, Fig. 8 (not shown), is provided with two blind slots, receiving bars in a fixed plate, the raised portions between the slots being engageable by the end 47 of the gear-shift lever to control the valves 44, 45. The hubs 65, 66 of the gear strikers are provided with a blind slot 67 and through slots 68-70 for engagement by the gear-shift lever end 47. The slots &c. coact, e.g. as shown, to provide interlocking, and ensure the correct sequence of engagement of the positive clutches, &c. 9, 22 and the double friction clutch S 1 ,S 2 when shifting, e.g. from third speed to engine braking speed.