Exhaust emission control for internal combustion engines utilizing anelectrically heated choke

Claim 2

In an internal combustion engine having a fuel system comprising a carburetor for mixing fuel and air prior to the entry of the mixture into a cylinder, and a choke valve positioned within the air intake passage of the carburetor, said valve responsive to a thermal bimetal member for controlling the amount of air into the carburetor, an improved exhaust emission control comprising: a first normally open switch electrically connected to one side of a source of power; a second normally open thermostatic switch electrically connected in series circuit with said first switch and responsive to a predetermined temperature for actuation; a third normally closed thermostatic time delay switch electrically connected in series circuit with said second switch, said third switch responsive to a predetermined temperature for a predetermined period of time for actuation, and a heating element electrically connected in series circuit between said third switch and the other side of the source of power, said heating element positioned in thermal relationship to the thermal bimetal member for supplying heat thereto for a predetermined period of time controlled by said third switch when said first and second switches are actuated.

Claim 3

In the improved exhaust emission control according to claim 1 wherein said third switch comprises an electrically responsive heater winding electrically connected between the junction of said first and second switches and the other side of the source of power for generating a quantum of heat, and a thermal responsive bimetallic normally closed switch member, said switch member responsive to the quantum of heat after a predetermined period of time for actuation.

Claim 4

In the improved exhaust emission control according to claim 1 wherein said second thermostatic switch is responsive to temperatures exceeding 68*F. for actuation thereof.

Claim 5

In the improved exhaust emission control according to claim 1 additionally including a resistor electrically connected in parallel circuit with said second thermostatic switch for supplying reduced electrical power to said heating element when said second switch is open and said first and third switches are closed.

Claim 6

In the improved exhaust emission control according to claim 1 additionally including an engine-operation responsive switch in electrical series with said second and third thermostatic switches for controlling the application of electric power to said heating element until the engine is iN operation.

Claim 7

In an internal combustion engine having a carburetor for mixing fuel and air prior to the entry of the mixture into a cylinder, and a choke valve positioned within the air intake tube of the carburetor for controlling the amount of air into the carburetor, said valve responsive to a thermal responsive actuating member, an exhaust emission control system comprising: an electrothermal control device having; a thermal responsive switch normally open and actuated to a closed position at a predetermined temperature; and a thermal responsive time delay switch normally in a closed position and responsive to a predetermined temperature for actuation to an open position, said first mentioned switch and said time delay switch electrically connected in a series to a source of electrical power; and a heater member positioned in a thermal coupling relationship with the thermal responsive actuating member controlling the choke valve, said heater responsive to the flow of current through said electrothermal control device for radiating thermal energy for actuating the choke valve to increase the flow of air into the carburetor after a predetermined period of time as determined by said time delay switch thereby maintaining a more combustible mixture in the cylinder at a level to reduce the amount of hydrocarbons and carbon monoxide gases exhausted from the cylinder.

Claim 8

In an internal combustion engine having a carburetor for mixing fuel and air prior to the entry of the mixture into a cylinder, and a choke valve positioned within the air intake tube of the carburetor for controlling the amount of air into the carburetor, said valve responsive to a thermal responsive actuating member, an exhaust emission control system comprising: an electrothermal control device having; a thermal responsive switch normally open and actuated to a closed position at a predetermined temperature; and a thermal responsive time delay switch normally in a closed position and responsive to a predetermined temperature for actuation to an open position, said first mentioned switch and said time delay switch electrically connected in a series to a source of electrical power; and a heater member positioned in a thermal coupling relationship with the thermal responsive actuating member controlling the choke valve, said heater responsive to the flow of current through said electrothermal control device for radiating thermal energy for actuating the choke valve to increase the flow of air into the carburetor after a predetermined period of time as determined by said time delay switch thereby maintaining a more combustible mixture in the cylinder at a level to reduce the amount of hydrocarbons and carbon monoxide gases exhausted from the cylinder.

Claim 9

In the exhaust emission control system according to claim 6 further including a resistor electrically connected in parallel with said first mentioned thermal responsive switch reducing the power supplied to the heater member when said first switch is open and said thermal responsive time delay switch is closed.

Claim 10

In the exhaust emission control system according to claim 6 wherein said electrothermal control device comprises: a housing member having a pair of spaced apart broadsides wherein one of said broadsides is open forming a receiving means, said housing member having a plurality of spaced apart tab members positioned around the periphery of said opening; an electrically non-conductive base member having a pair of spaced broadsides substantially the size of said opening of said housing member, said base member supporting on one broadside thereof said thermal responsive switch and said thermal responsive time delay switch and on the other broadside having a pair of terminals electrically connected respectively to the actuating arm of each of said switches; and gasket means extending around the periphery of said one broadside of said base member and cooperating with said tab members to seal said switch members within said housing member thereby preventing corrosive particles from engaging with said switches.

Claim 11

In the exhaust emission control system of claim 8 wherein said thermal responsive time delay switch comprises: an electrically responsive heater element electrically connected at one end thereof in series with said first mentioned switch and at the other end to a source of power; and a pair of switch members, the actuating arm being a bimetallic member responsive to heat generated by said heater element for a period of time for actuation to an electrically opened switch position.

Claim 12

In the exhaust emission control system of claim 8 wherein said first mentioned thermal responsive switch comprises: a pair of switch members, the actuating arm being a bimetallic member responsive to temperature exceeding 68*F. for actuation to an electrically closed switch position.

Claim 13

In the exhaust emission control system according to claim 8 wherein said base member is a rigid non-porous, non-deformable member of glass-filled alkyd material wherein said broadsides are substantially parallel.

Claim 14

In the exhaust emission control system according to claim 8 wherein said housing member is an electrically conductive member having means for mounting said member to said engine thereby maintaining said housing at the electrical potential of Said engine.

Claim 15

In the exhaust emission control system according to claim 12 wherein one of said tabs on said housing is electrically connected to the other end of said heater element.