Patent ID: 8820589

Claim:
A discharge assembly for discharging a metered volume of a liquid held in a pressurised or pressurisable container, said assembly comprising: (i) an elongate tubular housing having a liquid inlet at a first end thereof, (ii) a valve stem having a body locating within said housing and having a portion projecting from the second end of said housing, said valve stem being axially moveable relative to the housing between a first limit portion at which the assembly is closed to liquid discharge and a second limit position for discharge of the metered volume, (iii) a chamber provided within the body of the valve stem and having a liquid inlet at a first end of the chamber adjacent said first end of the housing and a first fluid transfer passageway towards the opposite, second end of the chamber, said first fluid transfer passageway providing communication between the chamber and the exterior of the valve stem, and (iv) a liquid discharge element moveable along said chamber from a liquid primed position to a liquid discharged position to effect discharge of the metered volume of liquid, wherein (a) the exterior of the body of the valve stem and the interior of the housing are configured such that in the first position of the valve stem there is second fluid transfer passageway along the outside of the valve stem between the inlet of the housing and a head portion of said valve stem, and (b) a seal is provided for relative sliding movement onto an annular step as the valve stem moves from its first to second position to close said second fluid transfer passageway to fluid flow, wherein the liquid discharge element is spherical; wherein the liquid discharge element is free from physical contact with a return spring.