GB1345069A - - Google Patents

Abstract

1345069 Spray carburetters P GELE B LAPRADE and X LAPRADE 17 Nov 1971 [20 Nov 1970] 53290/71 Heading F1B Constant depression carburetter has a main passage 1b containing a valve 4b and auxiliary passage 1a containing a valve 4a. The auxiliary passage valve 4a is externally controlled by a linkage 6a which is attached to the main passage valve 4b by a lost-motion connection so that the valve 4b is closed as the valve 4a closes. The main passage valve 4b is also connected by a rod 6b to a diaphragm in a capsule 33, which is connected by a pipe 32 to a chamber 2a defined by the main passage valve 4b and an additional valve 7. Depression in the chamber 2a causes the valve 4b to move in the opening direction. The additional valve 7 is connected by a linkage 9, 10 to a fuel control needle 11 which cooperates with a jet 19 mounted in a float-chamber 1c. Fuel passing through jet 19 mixes with air entering through an orifice 22 and the mixture passes along a pipe 20a to the auxiliary passage 1a and down this passage to a Venturi 26. In the auxiliary passage there is also an additional valve 13a mounted on a spindle which also carries a lever 13b; attached to one end of the lever is a spring 29 which is also attached to an adjustable screw 31, and attached to the other end is a spring 28 which is hooked on to a rod 27. This rod is pivotally connected at one end to a lever 8c fixed on the pivot shaft of the additional valve 7 and at its other end is free to slide through a hole in a boss 5e at the end of an arm 5d secured to the shaft 5b which carries the main passage valve 4b. The boss 5e co-operates with a slot in the rod 6c to form a lost motion connection. Mounted on the additional valve 7 is a spring arm 24 which biases a conical valve member 23 into a valve seat formed in the valve 7. Operation. The valves 7 and 12 are mounted offcentre and open as the air-flow increases, the movement of valve 7 being transmitted to needle 11 so that a fuel/air mixture issues from nozzle 20. The main valve 4b is opened by the depression in the chamber between the valves 7 and 4b, through the capsule 33 and is closed by the driver-controlled linkage 6a, 6c. During acceleration the main valve 4b opens more rapidly than the additional valve 7, so that the middle of the rod 27 moves to the right, increases the tension of the spring 28 and tends the close valve 12. Closure of valve 12 increases the depression in the space between valves 12 and 4a and increases the richness of the mixture by drawing fuel and air through nozzle 20. During idling the conical valve member 23 opens to allow additional air to pass through the opening 7a to augment the air entering through the opening 22.