Inventors:
Frank A. Tinker - Tucson AZ, 85740
International Classification:
B67D 508
Abstract:
A dispenser has a container for a liquid, a vent opening to allow air into the container, a valve to control the admission of air into the container, and a dispensing opening for the liquid to be dispensed therefrom. The dispenser is mounted with the dispensing opening at the bottom. When the valve is closed, a pressure differential is created that prevents the liquid in the container from flowing out. Upon opening of the vent valve, the pressure differential is reduced and dispensing can continue. Such a dispenser can be used to dispense fluids of varying viscosities and even nonporous solids. In one embodiment of the invention, an infrared radiation emitter and an infrared radiation detector are arranged in such a manner that, when a hand is placed below the dispenser, radiation from the emitter impinges on the hand and is reflected to the detector. Upon sensing the reflected radiation, the detector causes the valve for the vent tube to open so that the pressure differential in the container is eliminated and the liquid can be dispensed. When the hand is withdrawn, the detector no longer senses radiation from the emitter and causes the valve for the vent tube to close reestablishing the pressure differential that stops the outflow of liquid.