Run-on prevention device for internal combustion engines

Abstract

A device which prevents run-on continued operation of an internal combustion engine when the ignition is shut off: the device including means for preventing delayed closing of the throttle valve or valves when the ignition circuit is opened.

We claim: 
     
       1. A run-on preventing device for a fuel component duct of an internal combustion engine, the duct having a throttle valve, .[.a lever arm for controlling movement of the throttle valve,.]. a throttle control line for opening the throttle valve, .Iadd.a lever arm for controlling movement of the throttle valve, .Iaddend.and a closing spring opposing the throttle control line to close the throttle valve, the run-on preventing device comprising: a housing means; a diaphragm dividing the housing means into a vented chamber and a control chamber; a pin extending between the diaphragm and the lever arm; a spring backing the diaphragm for maintaining the pin in contact with the lever arm; a restricted outlet from the control chamber tending to delay closing of the throttle valve in response to the closing spring; a check valve to admit air to the control chamber when the control chamber expands; a bleed valve; a spring .Iadd.positioned within said control chamber .Iaddend.normally holding the bleed valve in its open position exposing the control chamber to atmospheric pressure; a solenoid control operable, when energized, to hold the bleed valve in its closed position, and operable, when de-energized, to permit the bleed valve spring to open the bleed valve; and an ignition switch having a closed position energizing the solenoid control to close the bleed valve in an off position de-energizing the solenoid control to open the bleed valve thereby to free the diaphragm for movement with the throttle valve to effect immediate closure in response to the closure spring. 
     
     
       2. A run-on preventing device as defined in claim 1, for an internal combustion engine having a fuel supply means, wherein: a normally closed valve means is provided for the fuel supply means; a solenoid actuator operable, when energized, to open the valve means, the solenoid actuator being connected with the ignition switch in parallel with the solenoid actuator to permit supply of fuel when the ignition switch is closed and to shut off the fuel supply when the ignition switch is opened. 
     
     
       3. For use with an internal combustion spark-ignition engine having an intake passage containing a throttle valve, a lever for operating the throttle valve, an actuator connected to the lever for opening the throttle valve and a .Iadd.first .Iaddend.spring for closing the throttle valve, the improvement comprising, in combination: a dampener device for impeding closing movement of the throttle valve, said dampener device including a housing having a control chamber provided with a movable wall, means connected to the movable wall and positioned for actuation by said lever to impede movement of the lever in a direction corresponding to closing movement of the throttle valve, impeding of such movement being accomplished by change of pressure in the control chamber caused by movement of said movable wall, means providing a restricted passage connecting said control chamber to atmosphere, resilient means acting on said movable wall in a direction opposing closing movement of the throttle valve, a solenoid-operated valve for connecting the control chamber to atmosphere, and means for connecting the solenoid valve for actuation of the engine ignition switch whereby opening the ignition switch serves to connect the control chamber to atmosphere to permit rapid closing of the throttle valve.[...]..Iadd., a second spring holding said solenoid operated valve open when said solenoid operated valve is not actuated, a venting passage communicating said control chamber to atmosphere, and check valve means in said venting passage preventing exhaust of said control chamber to atmosphere but allowing atmosphere to enter said exhaust chamber upon attainment of subatmospheric pressure therein when and as said resilient means produces movement of said movable wall and thereby causes enlargement of said control chamber.Iaddend.. 
     
     
       4. The combination set forth in claim 3 in which the means connected to the movable wall comprises an axially movable pin positioned to engage said lever arm. 
     
     
       5. .[.The combination set forth in claim 3 together with.]. .Iadd.For use with an internal combustion spark-ignition engine having an intake passage containing a throttle valve, a lever for opening the throttle valve and a spring for closing the throttle valve, the improvement comprising, in combination: a dampener device for impeding closing movement of the throttle valve, said dampener device including a housing having a control chamber provided with a movable wall, means connected to the movable wall and positioned for actuation by said lever to impede movement of the lever in a direction corresponding to closing movement of the throttle valve, impeding of such movement being accomplished by change of pressure in the control chamber caused by movement of said movable wall, means providing a restricted passage connecting said control chamber to atmosphere, resilient means acting on said movable wall in a direction opposing closing movement of the throttle valve, a solenoid-operated valve for connecting the control chamber to atmosphere, and means for connecting the solenoid valve for actuation by the engine ignition switch whereby opening the ignition switch serves to connect the control chamber to atmosphere to permit rapid closing of the throttle valve, a biasing means within said control chamber holding said solenoid-operated valve open when said solenoid-operated valve is not actuated, .Iaddend.a fuel supply conduit for the engine, a solenoid-operated valve for closing said conduit, and means for connecting the latter said solenoid-operated valve for actuation by the .[.engine.]. ignition switch. 
     
     
       6. The combination set forth in claim 3 in which said resilient means is positioned within said control chamber and wherein closing movement of the throttle valve acts to increase pressure in said control chamber. 
     
     
       7. For use with an internal combustion spark-ignition engine having an intake passage containing a throttle valve, a lever for operating said throttle valve, an actuator connected to the lever for opening the throttle valve and a spring for closing the throttle valve, the improvement comprising, in combination: a dampener device having means operated by said lever for impeding closing movement of the throttle valve, said dampener device having a control chamber of variable volume, means providing a restricted passage connecting said control chamber to atmosphere, a solenoid-operated valve for connecting the control chamber to atmosphere, and means for connecting the solenoid valve for actuation by the engine ignition switch whereby opening the ignition switch serves to connect the control chamber to atmosphere to disable the dampener device.[...]..Iadd., a biasing means within said control chamber holding said solenoid-operated valve open when said solenoid-operated valve is not actuated, a venting passage communicating said control chamber to atmosphere, and check valve means in said venting passage preventing exhaust of said control chamber to atmosphere but allowing atmosphere to enter said exhaust chamber upon attainment of subatmospheric pressure therein when and as said resilient means produces movement of said movable wall and thereby causes enlargement of said control chamber.Iaddend.. 
     
     
       8. For use with an internal combustion spark-ignition engine having an intake passage containing a throttle valve, a lever for operating said throttle valve, an actuator connected to the lever for opening the throttle valve and a spring for closing the throttle valve, the improvement comprising, in combination: a pneumatic dampener device having means operated by said lever for impeding closing movement of the throttle valve, said pneumatic dampener device having a control chamber of variable volume, a solenoid-operated valve for connecting the control chamber to atmosphere, and means for connecting the solenoid valve for actuation by the engine ignition switch whereby opening the ignition switch serves to connect the control chamber to atmosphere to disable the dampener device.[...]..Iadd., a biasing means within said control chamber holding said solenoid-operated valve open when said solenoid-operated valve is not actuated, a venting passage communicating said control chamber to atmosphere, and check valve means in said venting passage preventing exhaust of said control chamber to atmosphere but allowing atmosphere to enter said exhaust chamber upon attainment of subatmospheric pressure therein when and as said resilient means produces movement of said movable wall and thereby causes enlargement of said control chamber.Iaddend.. 
     
     
       9. For use with an internal combustion spark-ignition engine having an intake passage containing a throttle valve, a lever for operating said throttle valve, an actuator connected to the lever for opening the throttle valve and a spring for closing the throttle valve, the improvement comprising, in combination: a pneumatic dampener device having means operated by said lever for impeding closing movement of the throttle valve, said pneumatic dampener device having a control chamber of variable volume, electric means for venting the control chamber to atmosphere, and means for connecting said electric means for actuation by the engine ignition switch whereby opening the ignition switch serves to disable the dampener device.[...]..Iadd., a biasing means within said control chamber for venting said control chamber when said electric means is not actuated, a venting passage communicating said control chamber to atmosphere, and check valve means in said venting passage preventing exhaust of said control chamber to atmosphere but allowing atmosphere to enter said exhaust chamber upon attainment of subatmospheric pressure therein when and as said resilient means produces movement of said movable wall and thereby causes enlargement of said control chamber.Iaddend..