The present invention is a toy water gun for containment and ejection of water which includes a housing, an ejection nozzle, a bladder and an outlet connection which runs from the bladder to the nozzle. The expandable bladder is located in the housing and has a first end connected to the outlet connection...http://www.google.co.uk/patents/US6193107?utm_source=gb-gplus-sharePatent US6193107 - Bladder water gun
