US Patent 10440989 E-cigarette vaporizer cartridge filling method and apparatus

An e-cigarette vaporizer cartridge filling method and apparatus. The apparatus includes a liquid reservoir having an outlet end, the liquid reservoir for containing the liquid, a heater for heating the liquid in the liquid reservoir, and a liquid injection mechanism configured to draw portions of the heated liquid from an outlet end of the liquid reservoir and dispense the portions from an output end of the liquid injection mechanism. The method may allow for a human operator to control the time for filling the liquid injection mechanism with liquid based on visual observation of bubble formation and collapse therein.