Patent GB-534833-A (GB)
Title: Improvements in reversible internal combustion engines
IPC: F01L13/00
Filed: 1939-09-15
Abstract: 534,833. Starting ; reversing. AKTIEBOLAGET GOTAVERKEN. Sept. 15, 1939, No. 25950. Convention date, Sept. 17, 1938. [Class 7 (v)] In a reversible engine having a control shaft 1 movable in opposite directions from a " stop " position for controlling reversal of an engine part such as the fuel-pump cam shaft 42, a blocking member 74 is provided with stops 93, 94 one or other of which is always in the path of a member 104 on the control shaft, according to the setting of the fuel pump, so that the control shaft cannot be turned from the starting to the " normal running " (ahead or astern) position until means for moving the blocking member has been actuated by reversal of rotation of the engine. As shown, starting in either direction is effected by compressed air controlled by a main valve 3, a pilot valve 6 actuated by cams on a disc 15 on the control shaft, and a slide valve 8 normally closed by air pressure in a conduit 9. When the valve 6 is opened by one of the cams 15, the slide valve 8 admits air to a conduit 10 leading to starting- air valves 11 and to distributing valves 12 actuated by forward and reverse cams on a sleeve 21, which is moved axially by linkage 17- 20 from a double cam 16 on the control shaft. The distributing valves 12 admit air to conduits 14 to act upon pistons on the starting-air valves 11. Fuel is injected through a valve 22 by a pump 24 comprising a plunger 26 having a sloping recess.27 and adjustable about its axis, to vary the effective stroke, by means of a connecting-rod 36 carried by a cranked part 37 of the control shaft. The free end of the connecting rod travels over a sloping guide 38 and is connected by linkage 35-28 to the pump plunger. Reciprocation of the plunger is effected by symmetrical cams 41 on the shaft 42, which is adjusted for reversal by means of a bell-crank 77 actuated by a fluid-pressure piston 82. An engine-driven gear wheel 43 rotatable on the shaft 42 is engaged with angular play by a clutch member 47 secured on the shaft and by a clutch member 53 slidably keyed on the shaft and displaced by the bellcrank 77. A collar 63 threaded on a collar 62 secured to the wheel 43 has a splined connection 64 with the member 53 and has a groove 65 engaged by a bell-crank 67 connected by a link 69 to the blocking member 74. For reversal, the shaft 1 is turned past the neutral position, the cam sleeve 21 being shifted by the cam 16 to the reverse starting position and the pilot valve 6 being opened by the cam 15 to supply starting air to the valves 11, 12 so that the engine is stopped and then driven astern by the starting air. The member 104, Fig. 3, forces down the tappet 94 connected through a sliding member 95 and a lever 99 to a valve 90 by which compressed air is supplied to the piston 82, Fig. 2. This affects disengagement of the clutch member 53 and the gear 43, now being driven astern, takes up the angular play between it and the clutch member 47. The collar 63 travels axially on the threaded collar 62 to effect the movement of the blocking member 74 into its reverse position, allowing the shaft 1 to be turned sufficiently to bring the fuel pump into action and to regulate it by means of the linkage connected to the guided connecting-rod 36. The movement of the blocking member 74 also releases the tappet 94, allowing the valve 90 to connect the piston 82 to the atmosphere, so that the clutch 53 is reengaged by springs 59 in the angularly adjusted position of the shaft 42 and the fuel-pump cams 41 thereon. Specification 534,834 is referred to.