| 摘要 |
1,043,419. Reciprocating pumps. BARMER MASCHINENFABRIK A.G. July 22, 1963 [July 25, 1962], No. 28923/63. Heading F1A. A pump piston works in a sleeve 4 the interior of which is continually in communication with a space 6 through at least one hole 5. The pump draws liquid through an inlet 26 and discharges partly to a bore 17 and to pressure storage system through a connection 18 (Fig. 1, not shown). Liquid flows to a cylinder 37 via bores 17, and 34 the latter containing a restriction 33. A piston 40 in the cylinder 37 bears against an adjustable spring loaded valve 31 which is also subjected to the pressure of the pump cylinder. The pressure in the cylinder 40 and space 6 builds up with successive strokes of the piston 2 up to a pre-determined level. Whereupon at the next suction stroke of the piston 2, the piston 40 overcomes the effect of the spring 27 and pressure in the chamber 6 to lift the ball valve 31 and allow liquid to flow to the supply reservoir via an outlet bore 41. |
