Self-cleaning valve

摘要

A self-cleaning valve used at the outlet of a container has an elongated flexible flattenable outlet tube with an inlet for receiving material to be dispensed from the container, and an outlet for dispensing the material. In the at-rest condition of the valve, a pair of spring-biased rollers contact the opposite sides of the tube at a location spaced from the outlet end and hold the tube in a closed condition. When material is forced through the inlet end of the tube it pushes the rollers toward the outlet against the spring biasing action. At the outlet end the rollers separate and permit the tube to open so that the material can be dispensed. After the material has been dispensed, the springs return the rollers to the at-rest position and the rollers effect a self-cleaning action on the tube.