Air-driven pump system

An air-driven pump comprising:

• a source of pressurized air;
• a first pump unit including a first pump chamber, a first air chamber and a first end of stroke position;
• a second pump unit including a second pump chamber, a second air chamber and a second end of stroke position,
• an efficiency valve system pneumatically between the source of pressurized air and the first and second air chambers;
• a directional control valve pneumatically between the efficiency valve system and the first and second air chambers;
• a first air passage extending between the efficiency valve system and the directional control valve;
• a second air passage extending between the efficiency valve system and the directional control valve, the directional control valve shifting at the end of stroke positions to control air communication between the first and second air passages and the first and second air chambers, respectively, the efficiency valve system including a first valve position having unrestricted air communication between the source of pressurized air and the first air passage and restricted air communication between the source of pressurized air and the second air passage and a second valve position having unrestricted air communication between the source of pressurized air and the second air passage and restricted air communication between the source of pressurized air and the first air passage, the efficiency valve system shifting between the first and second valve positions before the directional control valve has shifted.

An air-driven pump comprising:

• a source of pressurized air;
• a first pump unit including a first pump chamber and a first air chamber;
• a second pump unit including a second pump chamber and a second air chamber,
• an efficiency valve system including a first air passage pneumatically between the source of pressurized air and the first air chamber and a second air passage pneumatically between the source of pressurized air and the second air chamber;
• a directional control valve pneumatically between the first air passage and the first air chamber and pneumatically between the second air passage and the second air chamber, the directional control valve selectively controlling air communication between the first and second air passages and the first and second air chambers, respectively, the efficiency valve system selectively restricting air communication between the source of pressurized air and the first and second air passages, unrestricted air communication and restricted air communication between the source of pressurized air and the directional control valve being concurrently in communication through the first and second air passages.

An air-driven pump comprising:

• a source of pressurized air;
• a first pump unit including a first pump chamber, a first air chamber and a first end of stroke position;
• a second pump unit including a second pump chamber, a second air chamber and a second end of stroke position;
• a directional control valve pneumatically between the source of pressurized air and the first and second air chambers, the directional control valve shifting responsive to end of stroke positions of the pump to selectively control air communication between the source of pressurized air and the first and second air chambers;
• an efficiency valve pneumatically between the source of pressurized air and the directional control valve in the air communication controlled by the directional control valve between the source of pressurized air and the first and second air chambers;
• a first air passage between the efficiency valve and the directional control valve in the air communication controlled by the directional control valve between the source of pressurized air and the first air chamber;
• a second air passage between the efficiency valve and the directional control valve in the air communication controlled by the directional control valve between the source of pressurized air and the second air chamber, the efficiency valve including a first valve position having unrestricted air communication with the first air passage and restricted air communication with the second air passage and a second valve position having unrestricted air communication with the second air passage and restricted air communication with the first air passage, the first and second valve positions being as the pump moves toward the end of stroke positions of the pump, respectively, and before the directional control valve has shifted.