摘要 |
<p>An automatic change-over system for stock rotation of liquids packages in plural collapsible bag-type reservoirs including an improved automatic change-over valve is described. The bag-type reservoirs are divided into primary and secondary groups, the primary group containing a supply of liquid product which is currently being dispensed and the secondary group containing a supply of liquid product which is held in reserve. An automatic change-over between the primary and secondary groups of bag-type reservoirs is effected in response to a vacuum created by an empty condition in the bags in the primary group. A pressure change in the system results from the deflation of the empty bag-type packages which switches the change-over valve. Thus, the change-over is caused by the characteristics of the flexible bags containing the liquid being dispensed and the valve mechanism which connects the primary group, the secondary group and a dispensing pump together.</p> |