Carburetor cold engine air/fuel mixture enrichment apparatus

Claim 2

AN AIR FUEL MIXTURE ENRIGHMENT APPARATUS FOR COLD WEATHER STARTING AND RUNNING OPERATION OF AN INTERNAL COMBUSTION ENGINE HAVING A CARBURETOR HAVING AN INDUCTION PASSAGE OPEN TO FRESH AIR AT ONE END AND ADAPTED TO BE CONNECTED AT THE OPPOSITE END TO THE ENGINE INTAKE MANIFOLD, A THROTTLE PLATE MOUNTED FOR ROTATION ACROSS THE PASSAGE BETWEEN CLOSED AND OPEN POSITIONS TO CONTROL THE FLOW OF AIR AND FUEL THERETHROUGH AND SPRING BIASED TO A CLOSED POSITION, A FUEL SUPPLY PORT CONNECTED TO THE PASSAGE AND RESPONSIVE TO MOVEMENT OF THE THROTTLE VALVE TO DIFFERENT POSITIONS TO INDUCE DIFFERENT QUANTITIES OF FUEL INTO THE PASSAGE, THE APPARATUS CHARACTERIZED BY CONTROL MEANS TO BOTH OPEN THE THROTTLE PLATE TO A WIDER OPEN THAN NORMAL POSITION TO INCREASE THE AIRFLOW AND TO INCREASE THE FUEL SUPPLY TO THE PASSAGE, THE CONTROL MEANS INCLUDING, FIRST MEANS ROTATABLE WITH THE THROTTLE PLATE, TEMPERATURE RESPONSIVE MEANS MOVABLE WITH CHANGES IN TEMPERATURE FROM A PREDETERMINED LEVEL AND FIXED TO A FAST IDLE CAM ENGAGED BY THE FIRST MEANS, THE FAST IDLE CAM HAVING A STEPPED EDGE CONSTRUCTION FOR THE INDIVIDUAL ENGAGEMENT OF EACH STEP WITH THE FIRST MEANS AS A FUNCTION OF THE MOVEMENT OF THE CAM BY THE TEMPERATURE RESPONSIVE MEANS, THE STEPS VARYING IN EXTENT OR PROJECTION SO AS TO PERMIT VARIABLE CLOSING OF THE THROTTLE VALVE AS A FUNCTION OF THE STEP ENGAGED, A FUEL CONDUIT CONNECTED TO THE INDUCTION PASSAGE AT A LOCATION SPACED FROM THE FUEL SUPPLY PORT TO SUPPLY ADDITIONAL FUEL TO THE PASSAGE, A NEEDLE VALVE MOVABLE INTO AND OUT OF THE CONDUIT TO CONTROL FUEL FLOW, CONNECTING MEANS OPERATIVELY INTERCONNECTING THE NEEDLE VALVE AND FAST IDLE CAM TO MOVE THE NEEDLE VALVE TO INCREASE THE FUEL SUPPLY WITH DECREASES IN TEMPERATURE, AND OTHER MEANS OPERABLY INTERENGAGING THE CAM AND FIRST MEANS DURING ENGINE START-UP OPERATIONS TO INCREASE THE THROTTLE PLATE OPENING POSITION BEYOND THE SCHEDULE PROVIDED BY THE STEPPED EDGE ENGAGEMENT WITH THE FIRST MEANS, THE OTHER COMPRISING A SECOND SURFACE ON THE CAM OF GREATER EXTENT OF PROJECTION INTO THE PATHE OF MOVEMENT OF THE FIRST MEANS THAN THE STEPS.

Claim 3

An apparatus in accordance with claim 1, including spring means normally biasing the second surface into engagement with the first means.

Claim 4

An apparatus as in claim 2, including means mounting the cam for axial movement, the spring means normally biasing the cam to a position engaging the second surface and first means.

Claim 5

An apparatus as in claim 3, including servo means operably by engine vacuum upon the attainment of an engine running condition to move the cam to a second position engaging the first means with the first series of steps, thereby moving the needle valve to reduce the flow of additiOnal fuel and permitting the throttle plate to move to a less open position to reduce airflow.

Claim 6

An apparatus as in claim 1, in which the second surface contains a second series of steps each of greater extent of projection than a step of the first mentioned series of steps.

Claim 7

An apparatus as in claim 1, in which the second surface contains a second series of steps corresponding in number and axially aligned with the first series of steps but each of a greater radial extent than the corresponding step of the first series of steps whereby the needle valve is moved further out of the conduit means and the throttle plate is opened wider for the same prevailing temperature level.

Claim 8

An air fuel mixture enrichment apparatus for the cold weather starting and running operation of an internal combustion engine having a carburetor having an induction passage open to fresh air at one end and adapted to be connected at its other end to the intake manifold, a throttle plate mounted for rotation across the passage to control the flow of air and fuel therethrough and spring biased to a closed position, a fuel supply port opening into the passage and responsive to movement of the throttle plate to different positions to induce different quantities of fuel into the passage, the apparatus characterized by, lever means fixed for rotation with the throttle plate, a shaft, a fast idle cam mounted for rotation with the shaft and having a limited axial movement with respect thereto, the cam having axially spaced first and second stepped edge surfaces, the surfaces being alternately engagable with the lever means as a function of the axial movement of the cam, the first and second surfaces each having a corresponding number of steps that are axially aligned with each other, with the steps of the first surface each extending radially a greater amount than the corresponding step of the second surface, a fuel conduit connected to the induction passage to the induction therein of fuel in addition to that supplied by the fuel supply port, a needle valve movable into and out of the conduit to variably admit or block flow of fuel through it, means operatively connecting the needle valve to the fast idle cam whereby rotation of the cam moves the needle valve, a temperature responsive element fixed to the shaft and movable in response to temperature changes to rotate the cam to various positions varying the flow of additional fuel and also presenting different ones of the steps of the stepped surfaces into engagement with the lever means, a vacuum servo having a force transmitting plunger biased by spring means in one direction and moved by engine running vacuum in the opposite direction, and means operatively connecting the plunger to the fast idle cam to move the same whereby inoperativeness of the servo during engine off and start-up operations permits the spring means to operatively bias the cam axially to a position presenting a step of the first surface in engagement with the lever means to open the throttle plate and move the needle valve to positions as determined by the rotative position of the cam, the servo in response to the attainment of an engine running condition axially moving the cam to present a corresponding step of the second surface of lesser radial extent against the lever means whereby the throttle plate is moved to a less open idle speed position.

Claim 9

An air fuel mixture enrichment apparatus for the cold weather starting and running operation of an internal combustion engine having a carburetor having an induction passage open to fresh air at one end and adapted to be connected at its other end to the intake manifold, a throttle plate mounted for rotation across the passage to control the flow of air and fuel therethrough and spring biased to a closed position, a fuel supply port opening into the passage and responsive to movement of the throttle plate to different positions to induce different quantities of fuel into the passage, the apparatus characterized by, lever means fixed for rotation with the throttle plate, a shaft, a fast idle cam mounted for rotation with the shaft and having a limited axial movement with respect thereto, the cam having axially spaced first and second stepped edge surfaces, the surfaces being alternately engagable with the lever means as a function of the axial movement of the cam, the first and second surfaces each having a corresponding number of steps that are axially aligned with each other, with the steps of the first surface each extending radially a greater amount than the corresponding step of the second surface, a fuel conduit connected to the induction passage to the induction therein of fuel in addition to that supplied by the fuel supply port, a needle valve movable into and out of the conduit to variably admit or block flow of fuel through it, means operatively connecting the needle valve to the fast idle cam whereby rotation of the cam moves the needle valve, a temperature responsive element fixed to the shaft and movable in response to temperature changes to rotate the cam to various positions varying the flow of additional fuel and also presenting different ones of the steps of the stepped surfaces into engagement with the lever means, a vacuum servo having a force transmitting plunger biased by spring means in one direction and moved by engine running vacuum in the opposite direction, and means operatively connecting the plunger to the fast idle cam to move the same whereby inoperativeness of the servo during engine off and start-up operations permits the spring means to operatively bias the cam axially to a position presenting a step of the first surface in engagement with the lever means to open the throttle plate and move the needle valve to positions as determined by the rotative position of the cam, the servo in response to the attainment of an engine running condition axially moving the cam to present a corresponding step of the second surface of lesser radial extent against the lever means whereby the throttle plate is moved to a less open idle speed position.

Claim 10

An apparatus as in claim 7, including a lever between the fast idle cam and needle valve, the lever being engaged and moved by the cam in a needle valve opening direction.