DOUBLE-RANGE PUMP GOVERNOR
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APNEUMATICALLY operated injection-pump governor can become rather unstable in the idling range, and to overcome this is the aim of an improved governor shown in patent No. 856,210. (E. Satzger, 6 Am Tabor, Vienna, Austria.)
The drawing shows a conventional injection pump having its rack-rod coupled to a piston (1) in a cylinder subject to intake suction. The cylinder is open to atmosphere on the side {2) while the other side is piped to a venturi (3) in the intake.
So much is common practice, but the novelty in this case is that the piston is a dual structure, its outer portion containing an inner piston (4).
Over the power range, the two pistons move in unison, but as they approach the idling position, that is, to the right, the outer one is arrested by an adjustable stop-screw (5). Thereafter the inner one alone moves as the suction becomes higher, but as its area is smaller, its movement is more stable. The patent shows also the same principle using a flexible diaphragm instead of a piston.