A dispenser for dispensing a substance, such as a liquid lipstick or other product, has a body defining a variable-volume storage chamber for storing the product. A dispensing portion is connected with the body and defines a bore coupled in fluid communication with the storage chamber for receiving product...http://www.google.es/patents/US7226231?utm_source=gb-gplus-sharePatente US7226231 - Piston-type dispenser with one-way valve for storing and dispensing metered amounts of substances
Piston-type dispenser with one-way valve for storing and dispensing metered ...
