A actuating head of a double-acting or lift and force pump for ejecting a product from a container includes an outlet duct leading to an ejection opening, wherein a valve closing piece is arranged in the outlet duct. Together with the outlet duct, the valve closing piece forms a check valve which, when...http://www.google.es/patents/US6776312?utm_source=gb-gplus-sharePatente US6776312 - Actuating head of a double-acting pump for ejecting a product from a container
Actuating head of a double-acting pump for ejecting a product from a container
