GB248909A - Improvements in or relating to internal combustion or other fluid-pressure engines - Google Patents

Abstract

248,909. Ricardo, H. R. Feb. 24, 1925. Reversing. - In an engine having sleeve valves positively actuated by rotary mechanism, the direction of rotation of the actuating mechanism is maintained constant when the crankshaft is reversed, and the mechanism is positively engaged and actuated only when there is the required angular relationship between this mechanism and the crank-shaft. In a six-cylinder engine, Fig. 1, each valve A is actuated from a lay shaft D through a skew gear C driving a crankshaft B having a crank pin B' engaging the valve by means of a selfaligning bearing A<1>. The shaft D is driven from the engine shaft through one or other of the bevel gears E engaging a bevel gear E<1> on a shaft E<2> driven through bevel gears F<1>, F<2>. The gears E are loose on the shaft D and are adapted to be engaged by positive clutches G when the engine and lay shafts are in the required angular relationship. The clutches G may be actuated by a hand lever or by a fluidpressure piston K<1>. In order to effect the necessary alteration in order of firing when the engine is reversed, the skew gears C of four cylinders are engaged with the corresponding shafts B in two different positions by means of clutches H<1> carried by members K<3> actuated by fluid-pressure pistons K<1>, which are all controlled from a cook L. Devices such as a magneto M and gear-wheel oil or water pumps, which are operative only in one direction of rotation, may be driven from the lay shaft, and other auxiliary devices, such as an ignition distributor M<1> and plunger pumps. from the shaft E<2>. In a modification, Fig. 5, the lay shaft Q is moved axially for reversing by means of a hand lever V<2> having ,a projection V<3> connected by springs V<4> to the arms V<5> of a lever V engaging the lay shaft. Four of the skew gears R are. fixed on the lay shaft to move axially on reversal, effecting relative rotation of the transverse valve-actuating shaft S'. The two remaining skew gears R<2> are splined on the lay shaft and prevented from .axial movement by the adjacent bearing U. For liquid-injection engines. a fuel pump W is actuated from each of the shafts S'. In an eight-cylinder engine, the cylinders are arranged in two groups of four, the cranks of one group being in a plane at right angles to those of the other group. A separate cranked lay shaft is used for each group, the cranks of one lay shaft being at 45‹ to those of the other; a phase-changing connection is interposed between the two lay shafts, so that one of them is turned through a right angle on reversing. The lay shafts are driven from the engine shaft through sprocket gearing and a reversing gear.