Patent GB-142018-A (GB)
Title: Improved hydraulic gear for the control of engine valves
IPC: F01L29/12
Filed: 1919-09-15
Abstract: 142,018. Scott's Shipbuilding & Engineering Co., and Nicholson, A. I. Sept. 15, 1919. Combined fluid-actuated and mechanical gears. -The inlet and exhaust valves 9, 10 of an engine are actuated by oil pressure supplied by a pump through rotary distributors 3, 4 controlled by a starting, stopping, and revrsing-valve 7. The pipes 52, 57 provide a constant pressure supply, and the valves 3, 4 a secondary supply to valveoperating devices 5, 6 of the kind described in Specification 144,504, [Class 135, Valves &c.], and which comprise differential pistons 100 subjected to primary and secondary supplies through passages 57<a>, 57<b>, 88, Figs. 1 and 1<a>. The oil is supplied through pipes 52 - - 57, and returns by pipes 58 - - 61, 62<c>. The valve 7 is operated by a handle 11 to distribute pressure oil through pipes 71, 72 to one or the other end of a piston 35 in valve 3, Figs. 1 and 2, and exhaust the other end. In the position shown in Fig. 2, the ahead ports 49, 49a are uncovered, and the reverse ports 49<b>, 49<c> are closed. The valve 7 comprises two parts; one part, Fig. 11, controls piston 35 through pipes 54, 72, 71; the other part, Fig. 12, controls the passages 85 - - 88. The oil distributors 3, 4 are driven by worm gearing 50. The distributor 3 controls the secondary supply of device 6 by pipe 63, and similarly by pipes 48, 88 the device 5 at starting. During normal running, the distributor 4 operates device 5. The shaft 31, Fig. 2, rotates a plug 32 with two sets of grooves in it; one set 37, 38, 39 controls valve 9 at starting, the other set 40, 41, 42 controls the exhaust valve 10. Groove 37 is divided into an exhaust section, which communicates with the plug interior 67 and a return pipe 60, and a pressure section 37<a>. Oil is supplied by a pipe 56, Fig. 1, to a longitudinal passage connected to grooves 38, 41, Fig. 2, which through transverse grooves connect to passages 37a, 39, 40, 42. By groove 37, 37a, pipe 48 is alternately put to pressure and exhaust and the valve 9 operated. The distributor 4, Fig. 5, is constructed similarly to the distributor 3, but has only three grooves. The plug 15 is operated through a lost-motion coupling 16 by shaft 31. A separate adjustable liner 19 is provided to con. trol the cut-off. The oil passes from connexion 22, through pipe 87 and valve 7 to apparatus 5. The connexion 48, Fig. 1, is divided into connexions 85, 86. At starting, one or the other of these connexions is brought into connexion with pipe 88 by ports 92, 93, 95 in valve 7, Fig. 12. When running, on further rotating the handle 11. the pipes 58, 86 are closed, and pipes 87, 88 connected. The dog coupling enables the valve to assume the correct position when running in the reverse direction. A modification is described suitable for two cylinders operating cranks at 180 degrees, or for a double-acting engine. The starting mechanism may be omitted, and ports in the distributor 3 and piston 35 duplicated, and shaft 31 directly connected to the plug 15. The distributor 3 may act alone with constant cut-off. The pressure in pipes 57<a>, 57<b> may be replaced by springs.