Cartridge based fluid dispensing apparatus

摘要

A concentrated flavor dispensing machine having displacement pumps for delivering between a fraction of a milliliter and a few ounces of fluids having a viscosity value between 1 to 4000 centepoise is described. The dispensing machine includes a cabinet for containing a multitude of displacement pumps, where each displacement pump is realizably connected to a disposable pre-filled fluid cartridge. Each displacement pump includes a stepper motor in engagement with a threaded drive rod that is advanced or retracted by any one of several predetermined distances. The drive rod impels a plunger positioned within the disposable cartridge to dispense a volume of fluid. Flexible capillary tubes connected to the output of each disposable cartridge direct the fluid to a central dispensing area. The disposable cartridge includes an expandable plunger which draws fluid back into the cartridge when the drive rod is withdrawn after a dispense operation for drip prevention.