| 摘要 |
A pump (1) is proposed for bringing up fluid, for example, a sampling pump for the investigation of ground water. Because it is intended for use in deep narrow holes (2) in rocky ground, it is characterised by having a small diameter throughout its length and includes a hydraulically driven pump piston working in a cylinder and sucking fluid within a limited intake area (12); this limited area is formed by a seal against the hole's (2) side walls. The seal is made by one or more cuffs (11) enclosing a space, into which a pressure medium is passed to expand the cuff's outside until it tightly abuts the borehole's side surface. The pump piston is driven by a drive medium, regulated from ground level and working under the pressure piston's lower surface, which causes a pump movement against the force of a return spring, by the supply of the drive medium from a source situated above the ground.<IMAGE> |
