GB1200568A - Carburettor for an internal combustion engine - Google Patents

Abstract

1,200,568. Spray carburetters. AUTOMOTIVE DEVELOPMENTS CORP. Dec.13, 1968 [Dec.14, 1967], No.59494/68. Heading F1B. In a carburetter having a throttle controlled induction passage 13 and an accelerating pump 55, Fig.4, for discharging fuel into the induction passage in response to rapid opening movement of the throttle valve 28, fuel is drawn from the pump on over-running when the vacuum in the induction passage downstream of the throttle valve exceeds a predetermined value. The accelerating pump 55 draws fuel through a check valve (63), Fig. 6 (not shown), from a float chamber defined by a cavity 18 in a member 17 forming part of the carburetter body 12 and a cavity 21, Fig.4, in a cover member 19 carrying the float 24, pivoted at 25 and controlling a needle valve 27. The pump is connected via a spring-biased ball valve (73), Fig.7 (not shown), to a passage 37, Fig. 5, in the throttle spindle 29 having air inlet passages 45 on its upstream side and mixture discharge passages 51 on its downstream side. When a predetermined vacuum is exceeded downstream of the throttle valve 28 the ball valve (73), Fig.7, is opened and fuel drawn from the pump 55. The main fuel supply to the spindle passage 37 from the float chamber is controlled by a vane 35, Fig.2, having a passage 36 extending from its lower end and communicating with the spindle passage 37. The vane 35 is connected to rotate with the spindle 29 and has its lower end variably spaced from the adjustable member 39. The float chamber is vented through a passage 93 to the carburetter air inlet 14. The vacuum advance system of an ignition distributer is connected to the interior of the float chamber in the idling position of the throttle valve to retard the ignition by means of passages (88, 89), Fig.8 (not shown), in the carburettor body 12 and a passage (92) in the fuel metering vane 35. A choke valve 94, Fig. 3, is operated by a temperature responsive mechanism 96. The choke valve shaft 95 is connected by a linkage 97 to a fast idle cam (98), Fig.1 (not shown), co-acting with an adjustable stop (99) carried by the throttle shaft. An electrical resistance heating element or water heated tube 101 is provided for heating the air on cold starting.