Vending machines have long been popular for dispensing food snacks because of the convenience. At first, vending machines were limited to dispensing packaged goods but have now been developed for dispensing goods that are prepared at the vending machine such as hot coffee, and chocolate. The trend continues to provide vending machines that mix and make the food product on demand rather than merely dispensing prepared and stored products. By mixing and making the product at the vending machine, a wider selection of flavors and choices are possible than from a vending machine that stores limited inventory of prepared products.
When such products are made on demand, valves need to control the addition of various flavors to the base ingredient. For example, flavored syrup added to a base ice-cream is usually provided in liquid form. Displacement pumps and control valves need to control the addition of such different flavored syrups. Back flow prevention valves are also needed to prevent air from back flowing into the supply line to contaminate the supply. Previous valves were overly complex and often resulted in intermixing of different flavors. Known selector valves that rotate from one inlet to another and have a null or off position tend to get gummed up and stuck when viscous sugary fluids are used as the sugar crystallizes in the valve.
What is needed is a dispensing valve that can control the flow of multiple supplies such as different flavors and be closeable and provide for a quick cleaning of the common downstream passages that receive the flow of a different supply with each dispensing. What is also needed is a valve capable of supplying a plurality of liquids with no rotary selector valve that provides for backflow prevention for preventing crystallization of any liquid syrups.