Carburetor emission control

Claim 2

An engine anti-dieseling carburetor throttle valve positioner comprising, in combination, an engine carburetor having an induction passage open to essentially atmospheric pressure at one end and adapted to be connected to an engine intake manifold at the opposite end so as to be subject to varying engine vacuum, a throttle valve rotatably mounted across the passage and movable from an essentially closed first position to a second engine idle speed position and beyond to a wide open throttle position, and return, for controlling flow through said passage, and control means to move the throttle valve to the first and second positions, the control means including first means operatively biasing the throttle valve to the first closed throttle antidiesel position, second means biasing the throttle valve towards the second position, a plunger operably engagable with and moving the throttle valve, manifold vacuum responsive means connected to the plunger for controlling the movement of the same, conduit means connecting the vacuum responsive means to the induction passage below the throttle valve, and means in the conduit means operable in response to engine shutdown to connect the conduit means immediately to atmospheric pressure prior to the natural bleeddown of manifold vacuum to the atmospheric level, the vacuum sensitive means containing a vacuum reservoir having an orifice type bleed and operable upon engine shutdown introduction of atmospheric pressure in the conduit means to initially move the throttle valve to the closed throttle first position to prevent engine dieseling and subsequently permit return movement of the throttle valve to the second open idle speed position by the second spring means to condition the engine for starting.

Claim 3

A throttle valve positioner as in claim 1, the vacuum responsive means including a vacuum servo having a movable diaphragm connected to the plunger and dividing the servo into first and second vacuum chambers, means connecting the first chamber to the conduit means, and flow restricting means interconnecting the first and second chambers for the slow bleed of vacuum into and out of the second chamber whereby upon engine shutdown the immediate decay of engine manifold vacuum in the first chamber to atmospheric pressure permits vacuum in the second chamber to effect movement of the throttle valve to the first closed throttle anti-diesel position, the subsequent decay of the vacuum in the second chamber through the flow restricting means permitting return movement of the throttle valve to the open throttle second position by the second spring means.

Claim 4

A positioner as in claim 1, the means in the conduit means comprising a valve movable between a vent position venting the conduit means to ambient pressure air, and a second position connecting the vacuum in the induction passage to the vacuum responsive means, and means biasing the valve towards the vent position.

Claim 5

A throttle positioner as in claim 3, including solenoid means connected to the valve for moving the same when energized to the second position, the solenoid having an operable connection to the ignition circuit of the engine to be responsive to engine operativeness and Inoperativeness for energization and deenergization thereof.

Claim 6

An engine anti-dieseling carburetor throttle valve positioner comprising, in combination, an engine carburetor having an induction passage open to essentially atmospheric pressure at one end and adapted to be connected to an engine intake manifold at the opposite end so as to be subject to varying engine vacuum, a throttle valve rotatably mounted across the passage and movable from an essentially closed first position to a second engine idle speed position and beyond to a wide open throttle position, and return, for controlling flow through said passage, and control means to move the throttle valve to the first and second positions, the control means comprising a vacuum servo having a flexible movable diaphragm dividing the servo into first and second vacuum chambers, plunger means connected to the diaphragm and projecting outwardly of the servo for operative engagement with the throttle valve, first spring means in the first chamber biasing the diaphragm and plunger to a first throttle valve open position, second spring means of lesser force than the first spring means operatively biasing the throttle valve towards a second closed position, conduit means connecting the second chamber to engine intake manifold vacuum, orifice means connecting the vacuum from the second chamber to the first chamber during engine operation to constitute the first chamber as a vacuum reservoir, a valve in the conduit means, spring means moving the valve to a first vent position connecting the conduit means to air at ambient pressure, and engine ignition circuit controlled solenoid means operably connected to the valve means for moving the same to a second position connecting vacuum in the induction passage to the second chamber in response to engine operation, whereby engine shutdown immediately effects movement of the valve to the first vent position decaying manifold vacuum in the second chamber, to atmospheric pressure the residual vacuum in the first chamber being effective to retract the diaphragm and permit a movement of the throttle valve to the closed anti-diesel second position until such time as sufficient vacuum in the first chamber is bled through the orifice to return the throttle valve to the open throttle first position by the first spring means.

Claim 7

An engine anti-dieseling carburetor throttle valve positioner comprising, in combination, an engine carburetor having an induction passage open to essentially atmospheric pressure at one end and adapted to be connected to an engine intake manifold at the opposite end so as to be subject to varying engine vacuum, a throttle valve rotatably mounted across the passage and movable from an essentially closed first position to a second engine idle speed position and beyond to a wide open throttle position, and return, for controlling flow through said passage, and control means to move the throttle valve to the first and second positions, the control means comprising a vacuum servo having a flexible movable diaphragm dividing the servo into first and second vacuum chambers, plunger means connected to the diaphragm and projecting outwardly of the servo for operative engagement with the throttle valve, first spring means in the first chamber biasing the diaphragm and plunger to a first throttle valve open position, second spring means of lesser force than the first spring means operatively biasing the throttle valve towards a second closed position, conduit means connecting the second chamber to engine intake manifold vacuum, orifice means connecting the vacuum from the second chamber to the first chamber during engine operation to constitute the first chamber as a vacuum reservoir, a valve in the conduit means, spring means moving the valve to a first vent position connecting the conduit means to air at ambient pressure, and engine ignition circuit controlled solenoid means operably connected to the valve means for moving the same to a second position connecting vacuum in the induction passage to the second chamber in response to engine operation, whereby engine shutdown immediately effects movement of the valve to the first vent position decaying manifold vacuum in the second chamber, to atmospheric pressure the residual vacuum in the first chamber being effective to retract the diaphragm and permit a movement of the throttle valve to the closed anti-diesel second position until such time as sufficient vacuum in the first chamber is bled through the orifice to return the throttle valve to the open throttle first position by the first spring means.