Patent GB-1453156-A (GB)
Title: Carburetor having a cold starting arrangement
IPC: F02M1/04
Filed: 1974-12-04
Abstract: 1453156 Spray carburetters FORD MOTOR CO Ltd 4 Dec 1974 [12 Dec 1973] 52354/74 Heading F1H A carburetter throttle valve 25 has a lever 232 operatively connected thereto and co-operating with the steps 224', 226, 228, 230 of a cam 224 which is positioned by an engine temperature responsive bi-metallic coil. A lever 254 has an end portion 252 insertable between the end 234 of the lever 232 and the cam steps which is withdrawn by operation of a servo 269, responsive of the vacuum downstream of the throttle valve, on starting of the associated engine. The bi-metallic coil (298), Fig. 1 (not shown), has its outer end 297 located in the slotted end 296 of a lever 292 fixed on a shaft 218 to which a lever 216 is fixed. The projection 222 of the cam 224 is biased into engagement with the adjustment screw 220 on the lever 216 by the weighted lower end 223 of the cam. A link 174 pivoted to the lever 216 determines the positions of needle valves 72 and 140 controlling respectively the application of the vacuum in an induction passage Venturi, Fig. 3 (not shown), to a servo (26) controlling the position of a movable wall (12) of the Venturi and the flow of fuel from a float chamber 20 to the induction passage adjacent the Venturi through a passage (128), Fig. 7 (not shown). A valve 100 controlling fuel flow from the chamber 20 to the same induction passage outlet as the flow past the valve 140 is operated by an abutment 114 on the valve 140. The communication between the fuel passage 114 and a passage (116), Fig. 8 (not shown), leading to the induction passage outlet is controlled by a unit (118) having a spring- biased valve which is opened by a solenoid only when the starter relay of the engine ignition system is operative. The solenoid energization circuit may include manifold vacuum and temperature switch permitting solenoid energization only below 2" Hg and 80‹F. The servo (26, Fig. 3) controlling the movable Venturi wall is connected to the carburetter induction passage downstream of the throttle valve 25 by passages (44, 48, 50), Fig. 10 (not shown), containing a restrictor (46) and at low temperatures of the bi-metallic coil the vacuum acting in the servo is substantially that downstream of the throttle valve so that the Venturi throat area is increased. The needle valve 372 gradually opens the opening 63 with increasing coil temperature so that Venturi vacuum predominates in the servo (26) at normal engine temperature. A metering needle (16, Fig. 3), connected to the movable Venturi wall is moved with the wall to vary the effective area of a main fuel jet (18). The bi-metallic coil is mounted in a cover (302, Fig. 1), secured to a housing (294), Fig. 2 (not shown), and air heated by passage over the engine exhaust manifold passes through the housing, a slot (304) in a gasket (303) between the housing and cover and the cover to an outlet in the carburetter induction passage downstream of the throttle valve. The carburetter includes a pair of induction passages (10, Fig. 1), having respective throttle valves and movable Venturi walls.