Adjustable metering pump

A reciprocating positive displacement pump of the type having expandable chambers operated in a feed stroke direction and in a suction stroke direction comprising:

• a first frame,
• a drive motor supported on said first frame,
• a reduction gear supported on said first frame and coupled to said drive motor and having a reduced speed output shaft,
• a first driven gear pivotally mounted on said first frame and coupled to said reduced speed output shaft,
• a first expandable chamber mounted on said first frame,
• a first driven member connected between said first driven gear and said first expandable chamber for movement of one end of said expandable chamber,
• a second frame connected to and adjacent to said first frame,
• a second driven gear pivotally mounted on said second frame and meshed with said first driven gear,
• a second first expandable chamber mounted on said second frame,
• a second driven member connected between said second driven gear and said second expandable chamber for movement of one end of said expandable chamber, whereby a plurality of expandable chamber displacement pumps are driven from a single drive motor, and
• first and second valve means connected respectively to said first and second expandable chambers each having an inlet valve which only opens when its associated expandable chamber is operated in a suction stroke direction, each said valve means further having an outlet valve which only opens when its associated expandable chamber is operated in the feed stroke direction.