Throttle positioning device

Abstract

A throttle positioning device comprising a housing and a diaphragm in the housing dividing the housing into first and second chambers. The housing has an opening extending to the first chamber for connection to vacuum. A solenoid is associated with the housing and has a plunger acted upon by energization of the solenoid. The plunger is yieldingly urged by a light spring against a solenoid stop connected to the diaphragm such that the stop is movable with the diaphragm. A stem is adapted to be moved by the plunger and extends through the movable stop to the exterior of said housing to define a movable throttle stop. The throttle lever, attached to the throttle shaft of the carburetor yieldingly urges the throttle stop to a retracted position against the lighter spring force of the solenoid plunger. The diaphragm is yieldingly urged to move the movable solenoid stop toward the solenoid. When the solenoid is energized and vacuum is not being supplied to the first chamber, the stem is in a first position, and when said solenoid is energized and vacuum is supplied to the first chamber, the stem is in a second position. When the engine is stopped and the solenoid de-energized, the throttle element urges the stop to a third position against the action of the lighter spring to provide an anti-dieseling function. In another form, the throttle positioning device includes a wall in the housing cooperating with the first diaphragm to form a second chamber, and a second diaphragm cooperates with the wall to define third and fourth chambers. The housing has an opening for connection to vacuum to the third chamber. The first and second diaphragms are movable independently of one another, such that when the solenoid is energized and vacuum is applied to the second opening, the second diaphragm moves the first diaphragm to move the magnetic stop permitting the stem to be moved by the solenoid plunger to a fourth position.