Variable venturi type carburator

Claim 1

A variable venturi carburetor having predictable and stable response characteristics in response to acceleration demands, said carburetor comprising a casing, a venturi portion in said casing, a fuel reservoir means in said casing, fuel metering jet means in said casing adjacent said venturi portion and adapted to meter fuel to said venturi portion in response to the venturi effect therein, said metering jet means being in communication with said fuel reservoir means, an air horn portion in said casing adjacent to and in communication with said venturi portion and adapted to provide air thereto, a mixing chamber portion in said casing adjacent to and in communication with said venturi portion and adapted to receive and mix air and fuel therefrom, a throttle valve positioned in said mixing chamber and adapted for movement between open and closed positions, a suction chamber in said casing in communication with said mixing chamber, guide means in said suction chamber, suction piston means in slidable and airtight contact with said suction chamber means and connected to said fuel metering jet means so as to control the amount of fuel admitted to said venturi portion, spring means normally biasing said suction piston means to decrease the amount of fuel provided by said fuel metering jet means. piston rod means on said suction piston means and positioned relative to said guide means so as to create a first airtight chamber, a gas damper chamber means between said suction piston means and said guide means, and a pressure transmission delaying means between said suction chamber and said gas damper chamber means, whereby movement of said suction piston means is predictably and accurrately controlled by the dampening caused by the gradual equalization of pressure between said gas damper chamber means and said suction chamber and the dampening caused by the resistance of the air in said first chamber means to movement of said piston rod means.