摘要 |
An inking pump for an offset printing press has a cylinder defining a bore in which a plunger is received for both rotation and linear reciprocation, creating a first and a second opposed fluid chamber. The cylinder has formed therein a first and a second suction port with a spacing therebetween axially of the bore, and, angularly spaced 180 degrees from the suction ports, a first and a second discharge port with an axial spacing therebetween. The plunger has formed in its surface a first recess for placing the first fluid chamber in successive communication with the first suction port and the first discharge port during each complete revolution of the plunger, and a second recess for placing the second fluid chamber in successive communication with the second suction port and the second discharge port during each complete revolution of the plunger. The first and second recesses are angularly spaced 180 degrees from each other about the plunger axis, so that the ink is delivered twice during each complete revolution, with concurrent one complete linear reciprocation, of the plunger.
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