Apparatus for reducing hydrocarbon content of engine exhaust gases during deceleration of automobile

Claim 2

In a carburetor for an automotive gasoline-powered internal combustion engine having a main mixture supply flow path to supply an air-fuel mixture to the engine under the control of a butterfly valve which is substantially fully closed during idling and deceleration and a slow running mixture supply flow path including a mixture passage leading from a fuel supply source and from at least two air bleeds for passing a controlled amount of air-fuel mixture therethrough, a slow running port communicating with said mixture passage and opening into said main mixture supply flow path at a position immediately upstream of the butterfly valve which is substantially fully closed, and an idling port communicating with said slow running port and opening into said main mixture supply flow path downstream of said butterfly valve, a system for reducing the hydrocarbon content of the exhaust gaseS emitted from the engine during deceleration, said system comprising vacuum responsive means which is responsive to a vacuum higher than the vacuums obtaining in the intake manifold during idling, valve means which is positioned relative to one of said at least two air bleeds and which is normally held in a position to open said one of said at least two air bleeds, and air passing means having a conduit providing air communication between the atmosphere and the intake manifold, which air communication is normally blocked by said valve means, said valve means being actuated by said vacuum responsive means to close one of said at least two air bleeds and to concurrently provide said communication.

Claim 3

A system according to claim 1, wherein said vacuum responsive means includes a diaphragm assembly comprising atmospheric and suction chambers which are separated from each other by a diaphragm member, said atmospheric chamber being vented to the atmosphere and said suction chamber communicating with the intake manifold through said conduit, and a compression spring accommodated in said suction chamber and biasing said diaphragm member to overcome vacuums lower than said vacuums obtaining during idling.

Claim 4

A system according to claim 2, wherein said valve means is rigidly connected to said diaphragm member and directed toward said one of said at least two air bleeds.

Claim 5

A system according to claim 2, wherein said conduit further communicates with the atmosphere through an opening formed in a valve seat on which said valve means is normally seated by the action of said compression spring, said valve means being unseated from said valve seat when said valve means is moved with said diaphragm member to open said one of said at least two air bleeds when a vacuum higher than said vacuums obtaining during idling is exerted to the diaphragm member.

Claim 6

A system according to claim 2, wherein said valve means comprises a solenoid assembly including a moving core serving as a valve member, a solenoid coil surrounding said moving core and electrically connected to an electric power source and a compression spring normally forcing said valve member away from the position to close said one of said at least two air bleeds and wherein said diaphragm assembly further comprises switch means including moving and stationary contacts electrically connected to said solenoid coil through said power source, said moving contact being secured to said diaphragm member and normally held disconnected from said stationary contact by the action of the first-named spring when said diaphragm member overpowers said vacuums lower than the intake manifold vacuums obtaining during idling whereby said valve member is normally held in a position to open said one of said at least two air bleeds and wherein said diaphragm assembly further comprises switch means including moving and stationary contacts electrically connected to said solenoid coil through said power source, said moving contact being secured to said diaphragm member and normally held disconnected from said stationary contact by the action of the first-named spring when said diaphragm member overpowers said vacuums lower than the intake manifold vacuums obtaining during idling whereby said valve member is normally held in a position to open said one of said at least two air bleeds and, when said solenoid coil is energized in response to a vacuum higher than the vacuums at idle, is unseated and moved to a position in which said one of said at least two air bleeds is closed and said conduit is permitted to communicate with the atmosphere.

Claim 7

A system according to claim 5, wherein said conduit communicates with the atmosphere through an opening formed in a valve seat on which said valve member is normally seated by the action of the first-named compression spring, said valve member being unseated from said valve seat when said solenoid coil is energized to move said valve member to a position in which said one of said at least two air bleeDs is closed thereby and said conduit is permitted to communicate with the atmosphere.