Induction air temperature control apparatus for an internal combustion engine

Claim 2

Apparatus to regulate the intake air temperature of an internal combustion engine, said engine including an intake manifold and a carburetor in communication with said intake manifold, said apparatus including first and second air inlet conduits, said first conduit opening to a source of ambient air, said second conduit opening to a source of heated air, means communicating each said conduit with said carburetor, valve means movable to open and close said first and second conduits so as to provide said carburetor with heated air or ambient air or a mixture of heated and ambient air, a vacuum motor connected to said valve means to move said valve means in response to a vacuum signal, a vacuum passage communicating said vacuum motor and a source of intake manifold vacuum, vacuum signal modulator means including a housing forming a portion of said vacuum passage, a first thermostatic valve means positioned within said housing constructed to open and close said vacuum passage, an orifice formed in said housing communicating said vacuum passage and a source of substantially atmospheric pressure, a second thermostatic member including a valve element cooperating with said orifice to progressively open and close said orifice, said first thermostatic valve means positioned between said orifice and said vacuum motor.

Claim 3

Apparatus to control the intake air temperature of an internal combustion engine, said engine including an intake manifold, a carburetor discharging into said intake manifold, an air cleaner filtering the air to be received by said carburetor and an exhaust manifold, said apparatus including first and second conduit means to deliver air to said air cleaner, said first conduit having an inlet opening adjacent the exhaust manifold and drawing heated air from about said exhaust manifold, said second conduit having an inlet opening at a position remote from exhaust manifold, flap valve means movable to open and close said conduits, a vacuum motor connected to said flap valve means to move said valve means in response to a vacuum signal, passage means interconnecting said vacuum motor and a source of intake manifold vacuum, vacuum signal modulator means including an enclosure forming a segment of said passage means, said enclosure being positioned within said air cleaner, said modulator means including a first thermostatic valve means positioned with said housing constructed to open and close said vacuum passage, an orifice formed in said enclosure communicating said vacuum passage and the interior of said air cleaner, a second thermostatic valve means including an element cooperating with said orifice to progressively open and close said orifice, said first thermostatic valve element positioned between said second thermostatic valve means and said vacuum motor, check valve means positioned between said second thermostatic valve means and said vacuum motor.

Claim 4

Apparatus to control the intake air temperature of an internal combustion engine, said engine including an intake manifold, a carburetor discharging into said intake manifold, an air cleaner filtering the air to be received by said carburetor and an exhaust manifold, said apparatus including first and second conduit means to deliver air to said air cleaner, said first conduit having an inlet opening adjacent the exhaust manifold and drawing heated air from about said exhaust manifold, said second conduit having an inlet opening at a position remote from exhaust manifold, flap valve means movable to open and close said conduits, a vacuum motor connected to said flap valve means to move said valve means in response to a vacuum signal, passage means interconnecting said vacuum motor and a source of intake manifold vacuum, vacuum signal modulator means including an enclosure forming a segment of said passage means, said enclosure being positioned within said air cleaner, said modulator means including a first thermostatic valve means positioned with said housing constructed to open and close said vacuum passage, an orifice formed in said enclosure communicating said vacuum passage and the interior of said air cleaner, a second thermostatic valve means including an element cooperating with said orifice to progressively open and close said orifice, said first thermostatic valve element positioned between said second thermostatic valve means and said vacuum motor, check valve means positioned between said second thermostatic valve means and said vacuum motor.

Claim 5

Apparatus according to claim 2, said first thermostatic valve means including a bimetal disc, said first valve means closing said passage means when the induction air temperature is below a first predetermined magnitude, said second thermostatic valve means including a cantilevered bimetal, said second valve means closing said orifice when the induction air temperature is below a second predetermined magnitude, said first predetermined temperature being below said second predetermined temperature.

Claim 6

Apparatus to control the intake air temperature of an internal combustion engine, said engine including an intake manifold, a carburetor discharging into the intake manifold, an air cleaner supplying air to the carburetor and an exhaust manifold, said air cleaner including a main housing and first air intake duct in communication with a source of ambient air and discharging into said main housing, a second air intake duct drawing heated air from adjacent the exhaust manifold and discharging into said first duct, a flap valve positioned at the junction of said first and second ducts and being movable to open and close said first and second ducts and to provide said carburetor with heated air from said second duct or ambient air from said first duct or a mixture of ambient and heated air, a vacuum motor connected to said flap valve to open said flap valve in response to an increase in vacuum pressure, a vacuum line communicating said vacuum motor and a source of intake manifold vacuum, vacuum signal modulator means positioned within said air cleaner, said modulator means including a housing, a bimetal thermostatic disc received in said enclosure, said disc including a centrally positioned resilient member, a first opening formed in said housing adjacent said resilient member communicating said enclosure and said vacuum line, said resilient member closing said first opening when the induction air temperature is below a first predetermined magnitude, a second opening formed in said housing communicating said enclosure and the interior of said air cleaner, a tapered valve element received in said second opening, a bimetal cantilever mounted to said housing supporting said tapered valve element within said second opening and moving said tapered valve element relative to said opening to progressively decrease the effective restriction thereof in response to increases in induction air temperature above a second predetermined magnitude.

Claim 7

Apparatus to control the intake air temperature of an internal combustion engine, said engine including an intake manifold, a carburetor discharging into the intake manifold, an air cleaner supplying air to the carburetor and an exhaust manifold, said air cleaner including a main housing and first air intake duct in communication with a source of ambient air and discharging into said main housing, a second air intake duct drawing heated air from adjacent the exhaust manifold and discharging into said first duct, a flap valve positioned at the junction of said first and second ducts and being movable to open and close said first and second ducts and to provide said carburetor with heated air from said second duct or ambient air from said first duct or a mixture of ambient and heated air, a vacuum motor connected to said flap valve to open said flap valve in response to an increase in vacuum pressure, a vacuum line communicating said vacuum motor and a source of intake manifold vacuum, vacuum signal modulator means positioned within said air cleaner, said modulator means including a housing, a bimetal thermostatic disc received in said enclosure, said disc including a centrally positioned resilient member, a first opening formed in said housing adjacent said resilient member communicating said enclosure and said vacuum line, said resilient member closing said first opening when the induction air temperature is below a first predetermined magnitude, a second opening formed in said housing communicating said enclosure and the interior of said air cleaner, a tapered valve element received in said second opening, a bimetal cantilever mounted to said housing supporting said tapered valve element within said second opening and moving said tapered valve element relative to said opening to progressively decrease the effective restriction thereof in response to increases in induction air temperature above a second predetermined magnitude.

Claim 8

Apparatus according to claim 4, an opening formed centrally within said disc, said resilient member received within said opening, said resilient member comprising in part a duck-bill type check valve including a hollow core extending into said opening having an open end and a closed end, a slit formed in said resilient member at the closed end of said hollow core, said check valve permitting the evacuation of atmospheric pressure from said vacuum motor when said first opening is closed.

Claim 9

Apparatus according to claim 5, said vacuum modulator enclosure comprising a segment of said vacuum line, a third opening formed in said enclosure communicating said enclosure and the source of intake manifold vacuum.

Claim 10

An improvement in apparatus to control the intake air temperature of an internal combustion engine that includes an intake manifold, a carburetor discharging into said intake manifold, an air cleaner filtering the air to be received by said carburetor and an exhaust, said apparatus also including first and second conduit means to deliver air to said air cleaner, said first conduit having an inlet opening adjacent the exhaust manifold and drawing heated air from about said exhaust manifold, said second conduit having an inlet opening at a position remote from exhaust manifold, flap valve means movable to open and close said conduits, a vacuum motor connected to said flap valve means to move said valve means in response to a vacuum signal, passage means interconnecting said vacuum motor and a source of intake mAnifold vacuum, said improvement comprising a vacuum signal modulator received within said air cleaner, said modulator having a first body portion and a second body portion defining an enclosure therebetween, said enclosure forming a segment of said vacuum line, a bimetal thermostatic disc received within said enclosure, a central opening formed in said disc, a resilient member received within said opening, a first port formed in said first body portion adjacent said resilient member, said resilient member on said bimetal disc overlying said first port when the induction air temperature sensed by the bimetal disc falls below a first predetermined magnitude, said first port being in communication with said vacuum motor, a second port formed in said first body portion adjacent said first port, said second port communicating said enclosure and the source of intake manifold vacuum, an orifice formed in the second body portion, tapered valve element received in said orifice and movable relative thereto to progressively open and close said orifice, said orifice opening to the interior of said air cleaner, passage means about the periphery of said disc communicating said second port and said orifice, a bimetal thermostatic cantilever mounted on the exterior of said second body portion supporting and positioning said tapered valve element within said orifice, said tapered valve element closing said orifice when the induction air temperatures sensed by said bimetal cantilever is below said second predetermined temperature.

Claim 11

An improvement in apparatus to control the intake air temperature of an internal combustion engine that includes an intake manifold, a carburetor discharging into said intake manifold, an air cleaner filtering the air to be received by said carburetor and an exhaust, said apparatus also including first and second conduit means to deliver air to said air cleaner, said first conduit having an inlet opening adjacent the exhaust manifold and drawing heated air from about said exhaust manifold, said second conduit having an inlet opening at a position remote from exhaust manifold, flap valve means movable to open and close said conduits, a vacuum motor connected to said flap valve means to move said valve means in response to a vacuum signal, passage means interconnecting said vacuum motor and a source of intake mAnifold vacuum, said improvement comprising a vacuum signal modulator received within said air cleaner, said modulator having a first body portion and a second body portion defining an enclosure therebetween, said enclosure forming a segment of said vacuum line, a bimetal thermostatic disc received within said enclosure, a central opening formed in said disc, a resilient member received within said opening, a first port formed in said first body portion adjacent said resilient member, said resilient member on said bimetal disc overlying said first port when the induction air temperature sensed by the bimetal disc falls below a first predetermined magnitude, said first port being in communication with said vacuum motor, a second port formed in said first body portion adjacent said first port, said second port communicating said enclosure and the source of intake manifold vacuum, an orifice formed in the second body portion, tapered valve element received in said orifice and movable relative thereto to progressively open and close said orifice, said orifice opening to the interior of said air cleaner, passage means about the periphery of said disc communicating said second port and said orifice, a bimetal thermostatic cantilever mounted on the exterior of said second body portion supporting and positioning said tapered valve element within said orifice, said tapered valve element closing said orifice when the induction air temperatures sensed by said bimetal cantilever is below said second predetermined temperature.

Claim 12

Apparatus according to claim 7, said resilient member comprising in part a duck-bill type check valve having a hollow core extending into said opening of said bimetal disc, said hollow core having an open end and a closed end, a slit formed in said resilient member at the closed end of said hollow core, said check valve, said check valve permitting the evacuation of atmospheric pressure from said vacuum motor when said first opening is closed.