Differential pressure metering device

Abstract

A metering end cap provided to the neck of a flexible container containing a fluid and intended to transfer, at will, an amount of fluid from an upstream space towards a downstream space, this end cap including a chamber in which is disposed a movable valve normally biased towards a rest position and operationally moved towards an end position. The valve isolates the upstream space and the downstream space from each other in its end position and only in this position, and the outlet of the chamber communicates with the upstream space for any position of the valve other that its end position.

1 . A metering device securable to a container adapted to contain a fluid for delivering a predetermined volume of the fluid in response to a rise in pressure of the fluid contained in the container, this metering device comprising:
 At least a hollow body at least partially insertable into a neck of the container and comprising a fluid inlet and a fluid outlet, the hollow body defining a chamber being in fluidic communication with the inlet and the outlet; and   a buoyant valve inserted into the chamber and movable between a rest position and an end position, the buoyant valve abutting the inlet when in the rest position, and substantially preventing the fluid from exiting the metering device from the outlet when in the end position, the buoyant valve being movable from the rest position towards the end position following the rise in pressure of the fluid contained in the container while some of the fluid is delivered via the outlet, and from the end position towards the rest position when the rise in pressure is released while air enters the container via the outlet of the chamber.   
     
     
         2 . The metering device of  claim 1 , wherein, when in the end position, the buoyant valve abuts an edge of the fluid outlet, thereby preventing the fluid from exiting the metering device. 
     
     
         3 . The metering device of  claim 1 , further comprising a sealing seat extending inwardly around the fluid outlet, the buoyant valve abutting the sealing seat when in the end position, thereby preventing the fluid from exiting the metering device. 
     
     
         4 . The metering device of  claim 1 , wherein the hollow body is provided with a groove surrounding at least partially the fluid inlet so as to prevent the buoyant valve, when in the rest position, from sealingly shutting-off the fluid inlet. 
     
     
         5 . The metering device of  claim 1 , further comprising a spring biasing the buoyant valve towards the rest position. 
     
     
         6 . The metering device of  claim 1 , wherein the buoyant valve comprises a truncated head cylindrical floater 
     
     
         7 . The metering device of  claim 1 , wherein the buoyant valve comprises a spherical floater. 
     
     
         8 . The metering device of  claim 1 , wherein the buoyant valve is hollow. 
     
     
         9 . The metering device of  claim 1 , wherein a neck of the container is oriented downwardly during the rise in pressure of the fluid in the upstream space.