VACUUM CONTROLLED THROTTLE POSITIONER AND DASHPOT

摘要

An integral device for controlling the rate of throttle closure and for preventing after run of an internal combustion engine is provided which utilizes a pair of diaphragm assemblies for accomplishing both functional operations. The device includes a dash pot stem having an axial opening through it. The opening is operatively connected to a source of engine vacuum. A diaphragm housing defining a chamber has a pair of diaphragm assemblies positioned in it. A first diaphragm assembly is mounted to the dash pot stem. The second diaphragm assembly is movably mounted on the dash pot stem and includes a shaft extending through the housing, The shaft is engagable with suitable linkage means operatively connected to a throttle valve of a carburetor for the engine. Upon engine start, the application of engine vacuum to a first side of the first diaphragm operates on the diaphragm and housing so that, in effect, the housing moves in a first direction, positioning the shaft at its curb idle position. The second diaphragm assembly extends the shaft as the engine begins to increase speed from curb idle, and acts to bring the carburetor slowly to its curb idle setting upon throttle release from the running condition. Removal of engine vacuum enables the first diaphragm to operate in conjunction with the housing to return the housing to its initial position, permitting the throttle to close below its curb idle setting.