| abstract |
Dosing system for a viscous material, and especially for pump sprays to deliver a spray of a pharmaceutical solution, has a container (16) for a liquid sealed externally on all sides, and linked to an impeller unit (5). A closure (21) is in the container wall. On emptying the container, a force is exerted by the ambient atmospheric pressure to alter the shape of the container at the closure. An indicator (18) is linked to the closure, so that the amount of closure movement is shown, to display the amount of liquid taken from the container. |