GB816392A - Improvements in or relating to valves more particularly for internal combustion engines - Google Patents

Abstract

816,392. Valves; inlet and exhaust passages. BUCHI, A. J. July 1, 1955 [July 2, 1954], No. 19163/55. Classes 7(2) and 7(6) [Also in Group XXIX] The inlet valve, Fig. 1, of an internal combustion engine comprises a bell-shaped head 1a in the domed or semispherical upper portion 1b of which are three, as shown, or more triangular orifices 1c, Fig. 2. with their apices adjacent the valve stem 1d, the orifices opening into an annular duct 4a communicating with the exhaust passage 4; the wall portions between the orifices 1c are straight as viewed in Fig. 2 and the orifice edges are rounded; the axial height of the orifices is less than the circumferential length at the base of the orifices. The duct 4a is as arranged with regard to the orifices 1c and passage 4 to reduce velocity and pressure losses to a minimum; the exhaust gases go round the head 1a in opposite directions and merge into a common stream in the passage 4. The poppet exhaust valve 2, Fig. 1, the seat of which opens into the inlet passage 3, formed as a spiral, co-operates with the mouth of the head 1a whilst its stem passes through and is supported by the stem 1d of the inlet valve 1; the valves 1, 2 are urged to the closed position by helical springs 8 and 7 respectively. The inlet valve 1 is supported by a cylindrical portion 11 that slides in an opening 12 in the cylinder head, the portion 11 being formed with a labyrinth or ring seal 13 to prevent communication between passages 3, 4. In a modification, the exhaust valve is loaded by a twin-coil torsion spring the coils being arranged one on each side of a yoke on the valve stem. The inner valve may control the air or mixture and the outer valve the exhaust gases. In another modification, the wall portions between the orifices are curved, as viewed axially, to obliquely join the body part of the head thereby permitting relative axial movement between the body part and the valve stem to accommodate any expansion resulting from the passage of exhaust gases therethrough. The valves may be used to control the admission and discharge of gases to and from a gas mixing chamber instead of an engine.