The invention relates to a manually operated pump able to dispense liquid or creamy substances at a predetermined constant pressure. The pump comprises a hollow main body carrying a dip tube and fixable to the mouth of a container containing the substance to be dispensed. The cavity of the main body...http://www.google.es/patents/US5301852?utm_source=gb-gplus-sharePatente US5301852 - Manually operated pump for dispensing liquid or creamy substances at a predetermined constant pressure
Manually operated pump for dispensing liquid or creamy substances at a ...
