A pump having a compressed-air-operated reciprocating motor for reciprocating
a
pump plunger through forward and return strokes. The motor comprises a motor cylinder
and a motor piston operable in the cylinder and itself acting as a valve for effecting
its return through each return stroke. A fluid dispenser is driven by the plunger
between a charge position for charging a dispensing chamber with fluid and a discharge
position for discharging fluid.
