Liquid dispensing apparatus

Claim 1

For use in a vacuum-controlled gravity-feed liquid dispensing system of the type in which a superposed reservoir supplies liquid to an underlying receptacle to maintain a relatively fixed level of liquid in the receptacle, an improved assembly for feeding liquid between the reservoir and the receptacle, said assembly comprising: A. a main conduit of relatively large cross-section having at one end a compartively open connection with the supply reservoir for both conducting air to the supply reservoir and for conducting liquid from the supply reservoir; and B. means partially blocking the other end of said main conduit but providing 1. a first passage by which liquid flowing from the supply reservoir into said main conduit may be admitted to the receptacle at a point below the intended normal surface level of said liquid in the receptacle; 2. a second passage of relatively limited cross-section opening at a point below the intended normal surface level of liquid in the receptacle, said second passage defining a. a first laterally directed orifice of relatively restricted cross-section communicating between the interior of said second passage and the interior of said main conduit to complete an open connection between a point below the intended normal surface level of liquid in the receptacle and the interior of the main conduit; and b. a second laterally directed air admitting orifice of relatively restricted cross-section located to have its center line approximately at the normal surface level of the liquid and communicating with the interior of said second passage, so that a slight lowering of the liquid will admit air through the main conduit by successive movement through said second orifice, said second passage and said first orifice.