Patent ID: 8561644

Claim:
A pulsator, comprising: a first valve chamber; a first electrically powered coil at least partially surrounding the first valve chamber and operable to generate a first magnetic flux; a first magnetic pole piece arranged in the valve chamber and having a metal surface; a first armature arranged in the valve chamber and having a first end nearest the magnetic pole piece and a second end, wherein the first end of the first armature has a metal surface and the second end has a first sealing surface and a second sealing surface, wherein the first sealing surface of the first armature is a separate component from the second sealing surface of the first armature; a first input port configured to admit atmospheric air to the first valve chamber; a second valve chamber; a second electrically powered coil at least partially surrounding the second valve chamber and operable to generate a second magnetic flux; a second magnetic pole piece arranged in the second valve chamber and having a metal surface; a second armature arranged in the second valve chamber and having a first end nearest the second magnetic pole piece and a second end, wherein the first end of the second armature has a metal surface and the second end has a first sealing surface and a second sealing surface; a second input port configured to admit atmospheric air to the second valve chamber; and a third input port coupled to a vacuum line.