GB404426A - An improved mechanism to operate hydraulically the valves of an internal combustion engine - Google Patents

Abstract

404,426. Valve gear ; reversing. THATCHER, A. J., and THATCHER, G. R., Atworth, near Melksham, Wiltshire. Oct. 25, 1932, No. 29785. [Classes 7 (v) and 7 (vi).] In fluid-actuated valve gear in which a camactuated plunger 1 acts upon fluid in a conduit 7 connected to the valve tappet, the plunger 1 is fitted with a second plunger which is arranged to slide in or over the plunger 1 for making up leakage from the conduit 7, the second plunger being formed with a surface adapted to seat upon the plunger 1 so as to act as a valve. The cam 5 works in an oil reservoir which is open to the rear of the second plunger 10 and the plunger 10 is connected to the cam follower 15. On the return stroke, the plunger 1 is stopped by a shoulder 11, but the plunger 10 continues its return movement so that its head, which acts as a valve, becomes unseated from a surface 17 on the plunger 1, thus opening a port 13 and allowing oil to enter through a groove 12 and the port 13 into the column of actuating-fluid. On the forcing stroke, the plunger 10 is brought again on to the seating 17, forcing any oil required to make up leakage into the conduit 7, and returning the surplus to the reservoir through the groove 12. The cam 5 may act on a series of plungers mounted radially in a ring 2 and connected to the inlet valves of the several cylinders of the engine, and a second cam and set of plungers may be arranged at the side of the first for actuating the exhaust valves. Timing of the valves is then adjusted by angular adjustment of the rings 2 about the cams ; and by retarding the inlet and advancing the exhaust valves sufficiently, reversing may be obtained, a second magneto being provided for reverse running.