GB1043607A - Improvements in and relating to a pneumatic starting system for internal combustion engines - Google Patents

Abstract

1,043,607. Starting engines. BURMEISTER & WAIN'S MASKIN-OG SKIBSBYGGERI A.B. April 15, 1964 [May 20, 1963], No. 15593/64. Heading F1K. In a compressed air starting system wherein the admission of compressed air to the starting. valves 38 and to a starting air distributer 30 controlling said valves is controlled by a starting slide valve 27 pneumatically operated from the engine control lever, the movement of the valve 27 back to its rest position in which it vents the pipes 3, 4, to the starting valve arrangement is delayed when the lever 1 is changed over from the start position to the engine operating position until all or most of the starting valves 38 open at the moment of change over have been closed. Each valve 38 is controlled by a slide valve 9 in the distributer block 30 actuated by a cam 5. With lever 1 in stop position, starting slide valve 2 is held closed by compressed air acting in space 32 and the valves 9 are held free of their cams 5. When lever 1 is moved to the "start" position, valve 54 is raised to vent pipe 46, which has portions formed by bores 45 in the stems of the valves 9, whereby the compressed air supplied through pipe 13 lifts valve 2 to supply compressed air through pipe 3 to the valves 38 and through pipe 4 to the distributer block 30. Passages 49 in a slide valve 12 admit the compressed air through ports 16 to the space between differential piston surfaces 9, 7 so that the valves 9 are forced down on to their respective cams 5 which operate the valves in succession to admit compressed air to pipe 15 to open the valves 38 cyclically to start the engine. Each cam 5 has a portion 19 in which the valves 9 are lifted to close valve 38 and portions 20, 21, in which the valves 9 are lowered to open the valves 38 over the period of compressed air admission, portion 20 corresponding to what would be the fuel injection period of the associated cylinder end portion 21 to the remainder of the starting air supply period. When lever 1 is moved to the operating range, the fuel supply to the engine is initiated and valve 54 is released to re-admit compressed air to pipe 46, whereby slide valve 12 is moved to the right so that vent ports 44 connect all the ports 10 to atmosphere. All the valves 9 on the parts 19 and 20 of the cams immediately return to their rest position but the valves on the ports 21 remain open as the corresponding ports 10 will be closed by the piston port 9. Compressed air will thus continue to be supplied to these cylinders until all the valves 9 have been returned to inoperative position by cams 5, whereupon bores 45 are all aligned with pipe 46 to permit compressed air to be transmitted to space 32 to close valve 2 and open the vent valve 34 to vent the pipes 3, 4. In a modification the valve 12 is operated with the valve 54 by lever 1, the valve 54 having a dashpot associated therewith which delays its return to its initial position a sufficient time to permit all the valves 9 to be closed by the cams 5 before the valve 2 is operated to vent the lines 3, 4.