Valve

A fluid dispenser valve comprising a valve body (10) containing a metering chamber (20), and a valve member (30) that is slidable in said valve body (10) between a rest position and a dispensing position so as to dispense the contents of said metering chamber (20) selectively, said valve member (30) being urged resiliently towards its rest position by a spring (8) that co-operates firstly with the valve body (10) and secondly with a radial collar (320) of the valve member (30), wherein said radial collar (320) is of a shape that is polygonal, the vertices (325) of said polygon being substantially rounded;

• and
• wherein, in the rest position of the valve member, said metering chamber is connected to a fluid reservoir containing the fluid to be dispensed, via a fluid-flow passage, so as to enable the metering chamber to be filled by gravity when, with the valve member in the rest position, the valve is upside down with the metering chamber disposed below the reservoir, and so as to enable said metering chamber to be emptied by gravity when, with the valve member in the rest position, the valve is upright with the metering chamber disposed above the reservoir.