Vacuum boost valve

摘要

A vacuum boost valve (10) senses when the intensity of vacuum from a variable intensity vacuum source (15) is about to drop below a threshold and supplies a boost so that when the intensity of the vacuum source (15) is within a range immediately below the threshold, the intensity of vacuum delivered to a load does not drop below the intensity of the vacuum source and is in fact increased over what it would otherwise be without the boost. The vacuum boost is obtained by using a venturi (22).