GB861597A - Improvements in carburettors having a float chamber for internal combustion engines - Google Patents

Abstract

861,597. Carburetters. SOC. INDUSTRIELLE DE BREVETS ET D'ETUDES S.I.B.E. June 17, 1959 [July 11, 1958], No. 20843/59. Class 7(3). A carburetter having a float chamber comprising means adapted to make the chamber communicate either with the air intake 7 of the carburetter downstream of a filter 8 provided on the air intake or with atmosphere is characterized in that the means are mechanicalpneumatic means sensitive both to the negative pressure prevailing in the induction manifold downstream of the throttle valve and to the position of the valve and such that they cause the float chamber to communicate with the air intake when the engine is operating and/or with the atmosphere when the engine is stopped. Thus when the engine is not operating and the throttle valve 2 is in the position corresponding to the throttled down state of the engine the lever 17 acts on the rod 16 and holds the rod in the upper position (Fig. 1). Since the piston 14 is not subjected to any negative pressure it occupies its upper position thus opening the valve 13. If the engine is started up and is idling, the negative pressure acts on the piston 14 pulling it downwards and the valve 13 closes. When the throttle valve 2 is opened the rod 16 moves downwards under the action of the spring 21 and holds the piston 14 in its lower position. In a modification, Fig. 3, the tube 11 is shut off from the float chamber when the orifice 12 is opened. Specification 746,245 is referred to.