Carburetor ambient mixture control

Claim 2

A carburetor having an induction passage connected to air at one end and to an engine intake manifold at the opposite end and having a venturi in between adapted to be connected to a source of fuel for the induction thereof into the passage in response to airflow therepast, a choke valve mounted anterior of the venturi and rotatable at times to control airflow therepast, an air passage for supplying air directly to the induction passage below the venturi, ambient pressure and temperature responsive means for controlling the overall air/fuel ratio in the intake manifold by controlling airflow through the air passage to compensate for chAnges in air density with changes in altitude and temperature, and separate means to maintain a controlled supply of air to the air passage when the choke valve is rotated to a choking position, the separate means comprising an air bleed opening of a controlled size, valve means movably mounted with respect to the air bleed opening to variably control the flow therethrough, and means connecting the valve means to the ambient pressure and temperature responsive means.

Claim 3

A carburetor having an induction passage connected to air at one end and to an engine intake manifold at the opposite end and having a venturi inbetween adapted to be connected to a source of fuel for the induction of fuel into the passage in response to airflow therepast, a choke valve mounted anterior of the venturi and rotatable at times to control airflow through the passage, an air passage for bypassing air around the venturi, the air passage being connected at its air inlet end to the induction passage between the choke valve and the venturi and at its other end to the induction passage below the venturi, valve means movable in response to ambient pressure and temperature changes for controlling airflow through the air passage to compensate for changes in air density with changes in altitude and temperature, and additional air inlet means for supplying air to the air passage when the choke valve is rotated to a choking position essentially closing the air passage air inlet, the additional air inlet means comprising an air bleed connected to the air passage outside of the induction passage and in a parallel flow relationship with the air inlet to the air passage, and second valve means movably mounted with respect to the air bleed to variably control flow therethrough, and connected to the first mentioned valve means for movement therewith.

Claim 4

A carburetor having an induction passage connected to air at one end and to an engine intake manifold at the opposite end and having a venturi inbetween adapted to be connected to a source of fuel for the induction of fuel into the passage in response to airflow therepast, a choke valve mounted anterior of the venturi and rotatable at times to control airflow through the passage, an air passage for bypassing air around the venturi, the air passage being connected at its air inlet end to the induction passage between the choke valve and the venturi and at its other end to the induction passage below the venturi, valve means movable in response to ambient pressure and temperature changes for controlling airflow through the air passage to compensate for changes in air density with changes in altitude and temperature, and additional air inlet means for supplying air to the air passage when the choke valve is rotated to a choking position essentially closing the air passage air inlet, the additional air inlet means comprising an air bleed connected to the air passage outside of the induction passage and in a parallel flow relationship with the air inlet to the air passage, and second valve means movably mounted with respect to the air bleed to variably control flow therethrough, and connected to the first mentioned valve means for movement therewith.