Fuel vapor and air mixing device with fuel-air ratio limiting means

Claim 1

A device for controlling the fuel-air ratio of a fuel vaporair mixture for supply to the induction passage of an internal combustion engine, said device comprising, in combination: a housing defining a chamber, said housing having an inlet for communication with a source of fuel vapor-air mixture of variable fuel-air ratio and main and restricted outlets for communication with said induction passage, whereby a stream of fuel vapor-air mixture is drawn through said chamber from said mixture inlet to said outlets, said housing further having an inlet for communication with a source of air for the admission of air into said chamber to reduce the fuel-air ratio of said mixture; an air valve in said air inlet for controlling the flow of air therethrough, said air valve having a closed position in which the flow of air through said air inlet is prevented; a valve positioning mechanism adapted to move said air valve to and from its closed position, said valve positioning mechanism including spring means for biasing said air valve away from its closed position; first and second substantially parallel electrically conducting wires in said chamber, one end of each of said wires being connected to a movable member, said first wire having its other end fixed with respect to said housing, said second wire being coated with an oxidation catalyst and having its other end connected to said valve positioning mechanism so that tension in said second wire is applied in opposition to the bias of said spring means, said movable member being biased away from said wires in a direction parallel to said wires so as to produce tension in at least one of said wires, said movable member normally producing in said second wire tension sufficient to hold said air valve in its closed position; said wires being connectible to a source of electric current for heating said wires to the activation temperature of said oxidation catalyst, said wires being positioned downstream from said air inlet in the path of only that portion of the stream of mixture flowing to said restricted outlet, whereby an increase in fuel-air ratio causes said second wire to increase in temperature and length relative to said first wire and thus allows said valve positioning mechanism to open said air valve to limit said fuelair ratio.

Claim 2

A device for controlling the fuel-air ratio of a fuel vaporair mixture for supply to the induction passage of an internal combustion engine, said device comprising, in combination: a housing defining a chamber, said housing having an inlet for communication with a source of fuel vapor-air mixture of variable fuel-air ratio and main and restricted outlets for communication with said induction passage, whereby a stream of fuel vapor-air mixture is drawn through said chamber from said mixture inlet to said outlets, said housing further having an inlet for communication with a source of air for the admission of air into said chamber to reduce the fuel-air ratio of said mixture; an air valve in said air inlet for controlling the flow of air therethrough, said air valve having a closed position in which the flow of air through said air inlet is prevented; a valve positioning mechanism adapted to move said air valve to and from its closed position, said valve positioning mechanism including spring means for biasing said air valve away from its closed position; first and second substantially parallel electrically conducting wires in said chamber, one end of each of said wires being connected to a movable member, said first wire having its other end fixed with respect to said housing, said second wire being coated with an oxidation catalyst and having its other end connected to said valve positioning mechanism so that tension in said second wire is applied in opposition to the bias of said spring means, said movable member being biased away from said wires in a direction parallel to said wires so as to produce tension in at least one of said wires, said movable member normally producing in said second wire tension sufficient to hold said air valve in its closed position; said wires being connectible to a source of electric current for heating said wires to the activation temperature of said oxidation catalyst, said wires being positioned downstream from said air inlet in the path of only that portion of the stream of mixture flowing to said restricted outlet, whereby an increase in fuel-air ratio causes said second wire to increase in temperature and length relative to said first wire and thus allows said valve positioning mechanism to open said air valve to limit said fuelair ratio.

Claim 4

A device for controlling the fuel-air ratio of a fuel vapor-air mixture for supply to the induction passage of an internal combustion engine, said device comprising, in combination: a housing defining a chamber, said housing having an inlet for communication with a source of fuel vapor-air mixture of variable fuel-air ratio, and main and restricted outlets for communication with said induction passage, whereby a stream of fuel vapor-air mixture is drawn through said chamber from said mixture inlet to said outlets, said housing further having an inlet for communication with a source of air for the admission of air into said chamber to reduce the fuel-air ratio of said mixture; an air valve in said air inlet for controlling the flow of air therethrough, said air valve having a closed position in which the flow of air through saiD air inlet is prevented; a mixture valve in said main outlet for controlling the flow of mixture therethrough, said mixture valve having a closed position in which the flow of mixture through said main outlet is restricted to a substantially lesser degree than the flow of mixture through said restricted outlet; a valve positioning mechanism adapted to move said air and mixture valves to and from their closed positions, said valve positioning mechanism linking said air and mixture valves for co-movement and including spring means for biasing said air and mixture valves away from their closed positions; first and second substantially parallel electrically conducting wires in said chamber, said first wire having one end thereof fixed with respect to said housing, said second wire having a coating of an oxidation catalyst material and having an end adjacent the fixed end of said first wire connected to said valve positioning mechanism so that tension produced in the second wire is applied in opposition to the bias of said spring means; a movable member in said chamber, said movable member being adapted to hold the other ends of said first and second wires and being biased away from said wires in a direction parallel to said wires so as to produce tension in at least one of said wires, said movable member normally producing in said second wire tension sufficient to hold said air and mixture valves in their closed position; said wires being connectible to a source of electric current for heating said wires to the activation temperature of said oxidation catalyst material, said wires being positioned downstream from said air inlet in the path of only that portion of the stream of mixture flowing to said restricted outlet, whereby an increase in fuel-air ratio causes said second wire to increase in temperature and length relative to said first wire and thus allows said valve positioning mechanism to open said air and mixture valves whereby said fuel-air ratio is limited with no concurrent decrease in the flow rate of gases from said source of fuel vapor-air mixture.

Claim 5

A device for controlling the fuel-air ratio of a fuel vapor-air mixture for supply to the induction passage of an internal combustion engine, said device comprising, in combination: a housing defining a chamber, said housing having an inlet for communication with a source of fuel vapor-air mixture of variable fuel-air ratio, and main and restricted outlets for communication with said induction passage, whereby a stream of fuel vapor-air mixture is drawn through said chamber from said mixture inlet to said outlets, said housing further having an inlet for communication with a source of air for the admission of air into said chamber to reduce the fuel-air ratio of said mixture; an air valve in said air inlet for controlling the flow of air therethrough, said air valve having a closed position in which the flow of air through saiD air inlet is prevented; a mixture valve in said main outlet for controlling the flow of mixture therethrough, said mixture valve having a closed position in which the flow of mixture through said main outlet is restricted to a substantially lesser degree than the flow of mixture through said restricted outlet; a valve positioning mechanism adapted to move said air and mixture valves to and from their closed positions, said valve positioning mechanism linking said air and mixture valves for co-movement and including spring means for biasing said air and mixture valves away from their closed positions; first and second substantially parallel electrically conducting wires in said chamber, said first wire having one end thereof fixed with respect to said housing, said second wire having a coating of an oxidation catalyst material and having an end adjacent the fixed end of said first wire connected to said valve positioning mechanism so that tension produced in the second wire is applied in opposition to the bias of said spring means; a movable member in said chamber, said movable member being adapted to hold the other ends of said first and second wires and being biased away from said wires in a direction parallel to said wires so as to produce tension in at least one of said wires, said movable member normally producing in said second wire tension sufficient to hold said air and mixture valves in their closed position; said wires being connectible to a source of electric current for heating said wires to the activation temperature of said oxidation catalyst material, said wires being positioned downstream from said air inlet in the path of only that portion of the stream of mixture flowing to said restricted outlet, whereby an increase in fuel-air ratio causes said second wire to increase in temperature and length relative to said first wire and thus allows said valve positioning mechanism to open said air and mixture valves whereby said fuel-air ratio is limited with no concurrent decrease in the flow rate of gases from said source of fuel vapor-air mixture.

Claim 6

A device for controlling the fuel-air ratio of a fuel vapor-air mixture for supply to the induction passage of an internal combustion engine, said device comprising, in combination: a housing defining a chamber, said housing having an inlet for communication with a source of fuel vapor-air mixture of variable fuel-air ratio and an outlet for communication with said induction passage, whereby a stream of fuel vapor-air mixture is drawn through said chamber from said mixture inlet to said outlet, said housing further having an inlet for communication with a source of air for the admission of air into said chamber to reduce the fuel vapor-air ration of said mixture; an air valve in said air inlet for controlling the flow of air therethrough, said air valve having a normally closed position in which the flow of air through said inlet is prevented; a valve positioning mechanism responsive to a fuel-air ratio signal to open said air inlet when said fuel-air ratio exceeds a reference level, whereby said fuel-air ratio is limited; and means in said chamber downstream from said air valve for generating said fuel-air ratio signal, said means comprising a pair of wires, one of said wires being coated with an oxidizing catalyst and the other not being so coated, said wires being so connected to said valve positioning mechanism that said valve positioning mechanism is responsive to the length of said catalyst coated wire relative to said other wire.

Claim 7

A device for controlling the fuel-air ratio of a fuel vapor-air mixture for supply to the induction passage of an internal combustion engine, said device comprising, in combination: a housing defining a chamber, said housing having an inlet for communication with a source of fuel vapor-air mixture of variable fuel-air ratio and an outlet for communication with said induction passage, whereby a stream of fuel vapor-air mixture is drawn through said chamber from said mixture inlet to said outlet, said housing further having an inlet for communication with a source of air for the admission of air into said chamber to reduce the fuel vapor-air ration of said mixture; an air valve in said air inlet for controlling the flow of air therethrough, said air valve having a normally closed position in which the flow of air through said inlet is prevented; a valve positioning mechanism responsive to a fuel-air ratio signal to open said air inlet when said fuel-air ratio exceeds a reference level, whereby said fuel-air ratio is limited; and means in said chamber downstream from said air valve for generating said fuel-air ratio signal, said means comprising a pair of wires, one of said wires being coated with an oxidizing catalyst and the other not being so coated, said wires being so connected to said valve positioning mechanism that said valve positioning mechanism is responsive to the length of said catalyst coated wire relative to said other wire.