Pumping breast milk

A portable, electric breast pump has an electronic controller adapted to track time and operate a solenoid to automatically maintain a predetermined suction and release rhythm as a function of time to mimic the natural sucking rhythm of an infant. Suction is produced by a continuously running diaphragm pump. A needle valve permits user vacuum level adjustment, but no other user control is required. A flapper valve in the top of the bottle reduces the suction rise time but incorporates a fixed amount of leakage to build a small amount of bottle pressure for pulling collected milk into the bottle during the release portion of the cycle. An improved bulkhead design helps to keep milk from entering the diaphragm pump if the unit is shaken or turned on its side.