| 摘要 |
A dispenser capable of dispensing a fluid via a vertically-oriented piezo device comprises a reservoir (10) containing a fluid (12) to be dispensed, an outlet (14) at a base portion of the reservoir, leading to a dispensing port (18) that comprises a piezo element (20) drivable to vibrate and thereby dispense fluid from the dispensing port, a bleed tube (32) communicating at one end with the dispensing port, extending therefrom to a location above the dispensing port, and including a selectively closeable valve (36), and a source of below-atmospheric pressure (24) to the portion of the reservoir above the fluid. The source of below-atmospheric pressure can be a piston (26), arranged to withdraw air or otherwise expand the volume above the fluid in the reservoir, thereby creating a zone of reduced air pressure. A refill suitable for such a dispensing apparatus comprises said reservoir containing the fluid to be dispensed and having an outlet at a lower extremity, and the upwardly-extending fluid conduit, separate from the reservoir, or only the reservoir containing the fluid to be dispensed with an outlet at a lower extremity of the reservoir and a port at an upper extremity of the reservoir for application of a below-atmospheric pressure. |
