LIQUID DISPENSING DEVICE HAVING A PRE-COMPRESSION OUTLET VALVE.

摘要

The invention relates to a liquid dispensing device comprising: a piston chamber; a piston that is moveable within the piston chamber to pressurise a liquid to be dispensed; a nozzle with a defined throughput for dispensing the liquid; an outlet valve having a defined minimum opening pressure arranged between the piston chamber and the nozzle; and a prime valve for priming the device. The prime valve may be mechanically operable and may be arranged on or in the piston. The liquid dispensing device may further comprise an operating member, which may protrude from an end wall of the piston chamber and which may be arranged to move the prime valve from a closed position to an open position when the moveable piston is near or at an end of its stroke. The outlet valve may be configured to minimize a difference between its opening pressure and its closing pressure. It may comprise a dome and the dome may have a stiffness which varies in radial direction.