Dispensing Apparatus and Valve Means

Abstract

According to the invention, there is provided a valve, and also dispensing or dosing apparatus ( 1 ) incorporating such a valve, for dispensing a predetermined dose of a first liquid into a second liquid, the apparatus comprising a sealed reservoir ( 10 ) for holding the first liquid, a reservoir outlet tube ( 24 ) connected to the reservoir at its in use upper region ( 18 ) and in fluid communication therewith, first valve means ( 30 ) for selectively dispensing a dose of the first liquid from the reservoir into the second liquid, and a dosing tube ( 26 ) between the reservoir outlet tube and the valve means. The apparatus is operable, when the reservoir holds the first liquid and on raising the level of the second liquid relative to the reservoir so as to subject the reservoir and first valve means to increased hydrostatic pressure, to discharge a dose of the first liquid into the dosing tube, via the reservoir outlet tube, and form a column of said first liquid that acts on the valve means, and subsequent lowering of the level of the second liquid relative to the apparatus so as to reduce the hydrostatic pressure acting on the reservoir and valve means causes the valve means to deliver the dose by opening of the valve means to allow dosing of the second liquid with the dose of the first liquid as the hydrostatic pressure acting on the valve means from the second liquid decreases below a predetermined amount.

1 . Dispensing apparatus for dispensing a predetermined dose of a first liquid into a second liquid, the apparatus comprising:
 a sealed reservoir for holding the first liquid;   a reservoir outlet tube connected to the reservoir at its in use upper region and in fluid communication therewith;   first valve means for selectively dispensing a dose of the first liquid from the reservoir into the second liquid; and   a dosing tube between the reservoir outlet tube and the valve means,   the apparatus being operable, when the reservoir holds the first liquid, and on raising the level of the second liquid relative to the reservoir so as to subject the reservoir and first valve means to increased hydrostatic pressure, to discharge a dose of the first liquid into the dosing tube, via the reservoir outlet tube, and form a column of the first liquid that acts on the valve means, and subsequent lowering of the level of the second liquid relative to the apparatus so as to reduce the hydrostatic pressure acting on the reservoir and valve means causes the valve means to deliver the dose by opening of the valve means to allow dosing of the second liquid with the dose of the first liquid as the hydrostatic pressure acting on the valve means from the second liquid decreases below a predetermined amount.   
     
     
         2 . Dispensing apparatus according to  claim 1 , the reservoir sides being sloped from the reservoir outlet to the widest portion of the reservoir. 
     
     
         3 . Dispensing apparatus according to  claim 1  the slope being at a constant angle. 
     
     
         4 . Dispensing apparatus according to  claim 2  (the reservoir outlet) being dove-tailed towards the outlet from the widest portion of the reservoir. 
     
     
         5 . Dispensing apparatus according to  claim 3 , wherein the reservoir outlet tube is mounted at the uppermost point of the reservoir. 
     
     
         6 . Dispensing apparatus according to  claim 1 , wherein the reservoir outlet tube extends at least partly in an in use upward direction from the in use uppermost point of the reservoir. 
     
     
         7 . Dispensing apparatus according to  claim 1 , further comprising a vent chamber connected between the reservoir outlet tube and the dosing tube, to allow a first liquid dose from the reservoir to travel from the reservoir to the dosing tube, while allowing air in the apparatus to be expelled. 
     
     
         8 . Dispensing apparatus according to  claim 1 , further comprising a plug at or adjacent to the outlet for sealing the reservoir before first use, the plug being removable by depression of the reservoir outlet tube into the reservoir. 
     
     
         9 . Dispensing apparatus according to  claim 1 , comprising a second reservoir, for holding a third liquid to be dispensed into the second liquid, and a second valve means, corresponding to the first valve means, for dispensing a dose of the third liquid from the second reservoir into the second liquid. 
     
     
         10 . Dispensing apparatus according to  claim 1 , wherein the reservoir is formed as a collapsible member 
     
     
         11 . Dispensing apparatus according to  claim 10 , wherein the reservoir is supported by a frame allowing communication of the second liquid inside and outside the frame. 
     
     
         12 . Dispensing apparatus according to  claim 10 , wherein the reservoir comprises flexible, corrugated sides, which collapse as the reservoir is emptied. 
     
     
         13 . Dispensing apparatus according to  claim 10 , wherein the reservoir collapses upwardly. 
     
     
         14 . Valve apparatus for controlling flow of a first liquid, the valve apparatus comprising:
 first and second opposed flexible membrane parts with a closable fluid channel formed therebetween, the valve apparatus being operable such that, when attached to an inlet tube containing a column of a first liquid and immersed in a second liquid so as to subject the valve apparatus to at least a minimum hydrostatic pressure, the hydrostatic pressure causes opposing faces of the membranes to close the fluid channel and prevent flow of the first liquid through the valve body, and, when a level of the second liquid is lowered relative to the valve apparatus so as to reduce the hydrostatic pressure, the flexible membranes separate to open the fluid channel, so as to allow a flow of the first liquid through the valve body.   
     
     
         15 . Valve apparatus according to  claim 14 , wherein the opposed membrane parts are joined to one another all around their margins to form the channel therebetween. 
     
     
         16 . Valve apparatus according to  claim 14 , wherein the fluid channel is closed by facing surfaces of the opposed membrane parts being pushed into mutual contact by the hydrostatic pressure of the second liquid. 
     
     
         17 . Valve apparatus according to  claim 14 , wherein the valve apparatus comprises an inlet and an outlet. 
     
     
         18 . Valve apparatus according to  claim 14 , wherein the inlet and outlet are formed in the first opposed membrane part. 
     
     
         19 . Valve apparatus according to  claim 14 , further comprising an outlet channel attached to the outlet of the valve apparatus, a first, upstream end of the outlet channel, in the direction of flow of the first liquid, being positioned lower, in an in use orientation, than a second, downstream end of the outlet channel, an upper portion of the outlet channel between the upstream and downstream ends being positioned higher than both the upstream and downstream ends. 
     
     
         20 . Valve apparatus according to  claim 14 , the upper portion being of sufficient length to trap an air column in the outlet channel between the first and second ends as the level of the second liquid rises from below the level of the second end to above the level of the upper portion. 
     
     
         21 . Valve apparatus according to  claim 19 , the internal diameter of the outlet channel increasing in a downstream direction, in a region downstream of the upper portion. 
     
     
         22 . Valve apparatus according to  claim 14 , the downstream end being formed with the channel directed downwards. 
     
     
         23 . Valve apparatus according to  claim 22 , with the end being tapered, arranged at an angle other than 90° to the channel at the downstream end. 
     
     
         24 . Valve apparatus according to  claim 14 , wherein a second valve apparatus is formed by a third flexible membrane part and the second membrane part, the third membrane part being arranged on an opposing side of the second membrane part to the first membrane part, a second closeable channel being formed therebetween. 
     
     
         25 . Valve apparatus according to  claim 24 , wherein the third membrane part is joined to the second membrane part all around their margins to form a closeable channel therebetween. 
     
     
         26 . Valve apparatus according to  claim 24 , wherein the second valve means also comprises an inlet and an outlet. 
     
     
         27 . Valve apparatus according to  claim 24 , wherein the inlet and outlet of the second valve apparatus are provided in the third membrane part. 
     
     
         28 - 32 . (canceled)