A piston pump dispenser having a reciprocating piston pump arrangement which, in a dispensing stroke, dispenses fluid from an outlet and, in a charging stroke, to draw fluid from a reservoir also draws back fluid from the outlet through which fluid is dispensed in the dispensing stroke. ...http://www.google.fr/patents/US20050276707?utm_source=gb-gplus-shareBrevet US20050276707 - Draw back pump
Numéro de demande: 10/938,701 Numéro de publication: US 2005/0276707 A1 Date de dépôt: 13 sept. 2004 Brevet délivré: US7267251 ( Date de délivrance 11 sept. 2007)
