Abstract:
A carburetor for an internal combustion engine with an accelerator fuel pump in the carburetor having a piston actuated by a cam on a throttle valve shaft and a ball between them. The axis of a pump chamber in which the piston is slidably received is offset from and eccentric to the axis of rotation of the throttle shaft so that little fuel is supplied to the operating engine by the accelerator pump as the shaft is rotated to move the throttle valve from its idle position to an intermediate position and most of the fuel supplied by the accelerator pump to the engine is delivered as the shaft is rotated to move the throttle valve from the intermediate position to its wide open throttle position. This provides a proper fuel mixture to the engine to accelerate it and avoids the problem of supplying an overly rich fuel mixture to the engine during acceleration and particularly if the operator moves the throttle valve several times back and forth between the idle and intermediate positions before moving the throttle valve to the wide open position to accelerate the engine.
Abstract:
An accelerator (28) having a main body defining a main chamber, a movable member (e.g., a diaphragm (34)) positioned within and dividing the main chamber into a pneumatic chamber (36) and a fuel chamber (38), and a damping orifice (62) (e.g., in the main body) interconnecting the pneumatic chamber (36) with a gas source (e.g., ambient air). The damping orifice (62) has a cross-sectional area less than about 0.002 square inches. To inhibit contamination of the accelerator, a filter (64) can be operatively positioned between the pneumatic chamber (36) and the ambient air.
Abstract:
A diaphragm carburetor with both the main metering nozzle and an idle circuit supplied with liquid fuel from the same metering chamber and an accelerator and shut-off assembly in the idle circuit. The assembly has a valve which is open to supply fuel to the idle circuit when the throttle is in a closed idle position and closes off the supply of fuel from the metering chamber as the throttle is moved to its wide open position. Opening of the throttle also actuates a piston to supply additional fuel for accelerating an engine.
Abstract:
The invention is directed to a dual barrel carburetor (10) for a motorcycle. The preferred carburetor (10) includes a novel combination of a fuel bowl assembly (20), a metering assembly (30), a main body assembly (40), and an air plenum assembly (50). The dual barrel carburetor (10) includes annular discharge booster venturis (404) associated with a main fuel delivery circuit (320). An idle circuit (314) opens downstream of the throttle plates (440). A transfer circuit discharge port (454) is positioned across the throttle plates (440). The combination of the idle (314), transfer (450), and main fuel (320) circuits ensures the smooth delivery of fuel throughout all operating conditions of the motorcycle engine.
Abstract:
In the carburetor 1A with the acceleration pump of the present embodiment, when a plunger 16 is stopped at the position of a top dead center in a cylinder 10 and the acceleration pump mechanism is not operated as in an idle operation or the like, a gap w having a predetermined width is formed between the tip of a rod 14A and a rod abutment face 16a of the plunger 16, whereby an operational error generated in a link system which transmits the opening/closing operation of a throttle valve to the rod is eliminated through this gap.
Abstract:
An acceleration device of a carburetor for a two cycle engine with a rotary dual valve which controls air flow through both a scavenging passage and a separate air intake passage each extending through a carburetor body. The carburetor body houses a metering fuel chamber and an air reference chamber defined by a diaphragm between them. Fuel in the metering fuel chamber is discharged through a port into the air intake passage. An acceleration pump has an actuation chamber which communicates with the scavenging passage and a pump chamber which communicates with the air reference chamber and a membrane between them. During engine acceleration the membrane is displaced by a pressure introduced into the actuation chamber to forcibly send air into the air reference chamber from the pump chamber to move, the diaphragm into the metering fuel chamber, and thereby increase the fuel delivered to the air intake passage.