Dispenser with piston assembly for expelling product
Abstract
Abstract A dispenser comprises an inner cylinder defining a contents chamber. A discharge valve is disposed at one longitudinal end of the chamber. A piston assembly disposed in the chamber is displaceable toward the valve for pressurizing the contents of the chamber. The piston includes longitudinally spaced ejector and energizer members with compressible air disposed therebetween for storing and transmitting energy from the energizer member to the ejector member. The air is confined by the sealing action of the ejector and energizer members against the inner cylinder. Alternatively, the air may be contained within a flexible enclosure extending between the ejector and energizer members, in order to avoid migration of air through the inner cylinder.
Inventors
- 👤 John E. Williams
Bibliographic Details
Claims Analysis
Total Claims: 7References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-26 | 1995-02-25 | 1995-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-26 | 1999-02-25 | 1999-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-26 | 2003-02-25 | 2003-08-27 | $7700.00 | Window Closed / Lapsed |