Spring biased fluid pump

摘要

A fluid pump having a fluid inlet, a fluid outlet, a pumping chamber, inlet and outlet check valves, and a pumping device that draws fluid into the pumping chamber and pumps fluid from the pumping chamber. The pumping device includes a pair of springs, a solenoid actuator, and a pumping diaphragm. During the energization stroke of the actuator, the movable member thereof moves substantially independently of the pumping diaphragm. One of the springs (51) instead urges the pumping diaphragm area (50) to cause a suction head in the pumping chamber. Since the strongest force output of a solenoid actuator ordinarily occurs at the instant of energization, the majority of such force output can be converted to work for storage in the other spring (72) during such energization without having to rely on such solenoid actuator to effect suction. After the solenoid actuator is deenergized, the second spring (72) effects substantially constant pumping pressure on the fluid in the pumping chamber.