Water absorbing fluid dispenser
Patent 4350271 Issued on September 21, 1982. Estimated Expiration Date: 
August 22, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
August 22, 2000. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3865108 Osmotic system with volume amplifier for increasing amount of agent delivered therefrom Patent #: 4203439 InventorApplicationNo. 06/180353 filed on 08/22/1980US Classes:222/386.5, Nonrigid follower604/892.1Osmotic or diffusion pumped device or systemExaminersPrimary: Rolla, Joseph J.Attorney, Agent or FirmInternational ClassesA61K 9/00 (20060101)A61M 31/00 (20060101) AbstractA fluid dispenser that operates by absorbing water is disclosed. The dispenser includes a rigid water permeable housing; a water insoluble, water swellable composition that fills a segment of the space within the housing, a lipophilic fluid charge that fills the remainder of the space within the housing and that is immiscible in the water-swellable composition, and an outlet through the housing that communicates with the fluid charge. In operation the water swellable composition absorbs water, expands, and in piston-like fashion displaces the fluid charge from the dispenser via the outlet. | |
