| 摘要 |
An electromagnetic pump particularly adapted for use with oil burners is disclosed. The pump embodies an armature that is reciprocated by a magnetic field produced by an electromagnetic coil. The armature drives the piston of a piston pump that is adapted to pump a liquid at low volume and high pressure. The pump also embodies a diaphragm disposed in a chamber having an inlet portion on one side of the diaphragm and an outlet portion on the other. The inlet portion of the chamber is connected to a liquid supply line leading to the pump and the outlet portion is connected to the discharge of the piston pump and also to a valve-controlled vent leading to atmosphere. The diaphragm is moved in one direction only by the armature and in the opposite direction by a spring. When there is air in the liquid supply line, the vent valve is opened and the diaphragm rapidly pumps air to the atmosphere. When liquid is discharged from the vent, the valve is closed. The discharge side of the diaphragm chamber is subject to the discharge pressure of the piston pump. This pressure holds the diaphragm in the inlet portion of the diaphragm chamber against the action of the spring when the vent valve is closed. Thus, the diaphragm becomes substantially inactive and requires substantially no power after air has been pumped out of the system and the piston pump is pumping liquid at normal discharge pressure.
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