Gas pressure driven fluid pump having pilot valve controlling disc-type motive and exhaust valves

A gas pressure driven fluid pump, said pump comprising:

• a pump tank having a liquid inlet and a liquid outlet;
• a float carried within the interior of said pump tank, said float being operable to move between a low level position and a high level position;
• pilot switching means operatively connected to said float for generating a first pilot signal when said float rises from said low level position to said high level position and generating a second pilot signal when said float falls from said high level position to said low level position, said first and second pilot signals being positive pressure actuation signals;
• pump control means for switching fluid communication with the interior of said pump tank between a source of pressurized gas and an exhaust sink, wherein said pump control means switches to the source of pressurized gas in response to said second pilot signal of said pilot switching means and the exhaust sink in response to said first pilot signal of said pilot switching means;
• and
• whereby liquid filling said pump tank causes said float to rise from said low level position to said high level position and liquid exiting said pump tank causes said float to fall from said high level position to said low level position due to introduction of the pressurized gas within said pump tank.

A system comprising:

• a pump tank with a liquid inlet and a liquid outlet;
• a rotary snap acting pilot valve operated by a float inside of said pump tank, said pilot valve being connected to a source of pressurized gas, said pilot valve snapping to a motive pilot signal position when the float reaches a first predetermined position and said pilot valve snapping to an exhaust pilot signal position when the float reaches a second predetermined position;
• an exhaust valve in fluid communication with said pump tank, said exhaust valve capable of switching between an open position and a closed position;
• a motive valve in fluid communication with said pump tank, said motive valve capable of switching between an open position and a closed position;
• a first conduit providing a fluid passage between said pilot valve and said exhaust valve to supply an exhaust pilot signal thereto, said exhaust pilot signal occurring when said pilot valve provides fluid communication between said source of pressurized gas and said exhaust valve;
• and
• a second conduit providing a fluid passage between said pilot valve and said motive valve to supply a motive pilot signal thereto, said motive pilot signal occurring when said pilot valve provides fluid communication between said source of pressurized gas and said motive valve.