Liquid filling device

Claim 1

A liquid filling device comprising: (a) a filling tube (4) for filling a liquid into a container; (b) a pressurized gas supply conduit (8) for introducing pressurized gas into the container for bringing the container under elevated pressure; (c) a gas discharge passage (9a) for discharging the pressurized gas into the atmosphere as the liquid surface level within the container moves upward, the gas discharge passage being branched into a first branch discharge conduit (12) and a second branch discharge passage (13), a bottom end of the first branch discharge conduit (12) being in communication with a neck of the container at a first position, a bottom end of the second branch discharge conduit (13) being in communication with the container at a second position below said the first position, at which second position the quantity of the liquid to be filled is determined, both upper end of the first branch discharge conduit (12) and the second branch discharge passage (13) being in communication with a valve operating chamber (11); and (d) a gas flow control valve (10) housed in the valve operating chamber (11) for opening or closing the gas discharge passage (9a) to permit or prohibit gas discharge into the environment, the gas flow control valve (10) being accommodated loosely in the valve operating chamber (11), wherein, said first branch discharge conduit (12) and said second branch discharge passage (13) are in communication with mutual opposite sides of the valve operating chamber (11) with respect to the gas flow control valve (10) before the liquid surface level reaches the second position in connection with the bottom end of said second branch discharge passage (13), and when the liquid surface has reached the second position and the bottom end of the second branch discharge passage (13) has been sealed thereby, the gas within the first branch discharge conduit (12) moves the gas flow control valve (10) upward, thereby sealing the gas discharge passage (9a).