A positive displacement pump (10) for precisely dispensing liquids through a dispensing tube (126) in which there is a pump body (12) having a shaft (18) fitted for reciprocating therein. Incremental adjusting nuts (24, 26) on an outer end (22) of the shaft limit the movement thereof in a pumping direction....http://www.google.es/patents/US4653673?utm_source=gb-gplus-sharePatente US4653673 - Pump for precisely dispensing liquids
