| 摘要 |
<p>A pump for fluent materials, and especially suitable for heavy and abrasive materials, has a piston in substantial clearance relation within a cylinder and operable in a pumping stroke to drive into a combination valving, wiping and sealing elastomeric ring about the discharge portion from the cylinder, so that the pumped material has minimal drag and wearing contact with relatively moving parts in the pump. The pump is adaptable for double action and proportional pumping. A self-reversing piston-driving fluid actuated motor is provided.</p> |
