GB1254168A - Carburettor having an automatic enrichment device for an internal combustion engine - Google Patents

Abstract

1,254,168. Spray carburetters. GURTNER S. A. Feb. 10, 1969 [Feb. 27, 1968, July 8, 1968], No.7059/69. Heading F1B. A carburetter with an automatic enrichment device comprises a fuel spray 5, Fig. 1 arranged to supply fuel into a conduit 2 having a throttle 7, on air or mixture strangler 10 acted upon whilst the engine is running by the vacuum downstream of the throttle via a tubular conduit between the conduit and the strangler housing, the housing being also connected to the air intake. Air is admitted from atmosphere through conduit 2 past the spray tube 5 to the inlet passage 3. The air strangler 10 is moved by piston 8 which is subjected to the vacuum downstream of the throttle valve 7 communicated via passages 11, 12 and 14. A shoulder 16 engages a projection 15 to move the piston 8. In modifications the plug 13 is replaced by a deformable membrane (21), Fig. 2 (not shown) and the passage 12 includes a non-return valve (20) or the piston 8 seats against the plug 13 with a toroidal joint (22), Fig. 3 (not shown), or a cup joint (23), Fig. 4 (not shown) or carries a valve seat (24), Fig. 5 (not shown) which engages the passage 14. Operation: At starting the space above piston 8 is connected to atmosphere via leakage apertures 17, 18 so that the air strangler 10 remains closed. The throttle valve 7 is raised to approximately half its full stroke and when the engine is running is raised fully so that shoulder 16 lifts piston 8. Apertures 17, 18 are closed and piston 8 is held engaged against plug 13 by the vacuum acting at 14, whilst the engine is running. In another embodiment the air strangler is omitted and a piston 108, Fig. 6 permits the supply of a rich mixture from air conduit 31 and fuel conduit 32 via chamber 26 and conduit 11 at starting the movement of throttle 107 lifts piston 108 to discontinue mixture enrichment as in Fig. 1. In an embodiment similar to Fig. 6 a piston (39), Fig. 7 (not shown) mounted in a diaphragm (37) is arranged perpendicularly to the throttle valve (107a). One piston end is formed with a cam (42) engaged by the throttle valve and the other piston end is formed as a needle valve controlling the passage (11). In a modification of this embodiment the diaphragm is omitted and the piston (39) is spring loaded.