摘要 |
A liquid material dispenser for dispensing medicaments includes a housing (2) formed with a reservoir (4) for the liquid to be dispensed, an outlet (6) through which the liquid is to be dispensed, and a connecting passageway (8) between the reservoir (4) and the outlet (6). A diaphragm (12) is located in a cavity (10) in the passageway (8) such that one side of the diaphragm (12) defines a pumping chamber (10a), and the other side defines a control chamber (10b). An electrolytic cell (14) generates a gas which is fed to the control chamber (10b) according to the quantity of electrical current passed through the electrolyte (14c), for driving the diaphragm (12) through forward strokes to pump liquid to the outlet (6); and a slow-acting vent (20) vents the gas from the control chamber (10b) to the atmosphere at a rate lower than that of generation of gas by the electrolytic cell (14), for driving the diaphragm (12) through return strokes to refill the pumping chamber (10a). |