Patent GB-368084-A (GB)
Title: Improvements in or relating to power transmission systems
IPC: B60K17/08
Filed: 1931-03-20
Abstract: 368,084. Controlling change speed gearing. NORRENBERG, B. G. E., 634, Rua Santo Antonio, Port Alegre, Rio Grande do Sul, Brazil. March 20, 1931, No. 8570. [Class 80 (ii).] In change-speed control mechanism suitable for vehicles, the movement of a selector lever 74, Fig. 1, causes the combined and sequential operation of the change-speed gear and the engine clutch, such speed gear and clutch being held in engagement by fluid pressure acting against springs, which disengage the clutch and speed gear in that order when the fluid pressure is removed in another speed change. The engine clutch 35, Fig. 2, is engaged against the thrust of a spring 37 by direct air pressure on a piston 42, which is connected to the clutch by a thrust rod 40 interrupted by balls 25 to prevent torque transmission. Change gears 45 or dog clutches are thrust in either direction into engagement by two selector bars 52, Fig. 3, against springs 53, Fig. 4. Each bar 52 is shifted to its two in-gear positions by a piston 61 which is double-acting, or by a single-acting piston at each end of the bar. Pressure air is cleared of water before entering the cylinders in chambers 22, Fig. 3, having a common drain cock 29. A pump 1, Fig. 1, draws air containing oil from the crank case of the engine 23 and delivers it to a receiver 3 from which it passes by a pipe 4 to the centre of a selector valve 5. From the valve 5 air passes by a pipe 6 to the clutch-engaging cylinder 16. Air passes selectively through pipes 7, 8, 9, &c. to the gear engaging cylinders 56 &c., Fig. 4. Th'e selector valve comprises two discs, A, B, Fig. 6, splined so as to turn together with the control lever 74. These discs are pressed apart against valve seats M, R by a spring C in an exhaust space K between them. Pressure air from the pipe 4 enters an enclosed space E which is connected by coplanar radiating passages F, G respectively to the gear and clutch engaging cylinders. The valve is shown with the passage F registering with the end of pipe 7, and through ports T, Fig. 7, connecting the other gear pipes 8, 9, &c. to the exhaust chamber K. Also the passage G is registering with one of a set of ports X, in the valve seat R leading by way of a collecting chamber H and pipe 6 to the clutch cylinder 16. Through ports S, Fig. 8, in the disc B, register with the ports X to connect the clutch cylinder 16 as required to the exhaust chamber K, which is connected by a duct 32 to a silencer 33, Fig. 1. The clutch engagement lags behind the gear engagement because of the volume of chamber H and cylinder 16. During disengagement, the clutch is operated first by making walls W<1>, Fig. 7, in disc A wider than the corresponding walls W, Fig. 8, in disc B. The clutch-engaging pipe 6, Fig. 1, is interrupted by a valve 26<1> connected by a lever 17 to a pedal 18 which may operate the vehicle brake. Depression of the pedal 18 cuts off the pressure air and opens the cylinder 16 to an exhaust pipe 34 which may sound a horn 19, this escape of air disconnecting the drive. A valve 27<1> allows oil-free air to be pumped for filling tyres through a duct 31.