Balloon gas tank filling piece

A filling piece coupling assembly, for filling a balloon, configured to be connected to a gas tank, containing pressurized helium gas, comprising:

• a coupling piece, configured to be fixed to the gas tank and comprising a circumferential wall, which defines an interior of the coupling piece,
• wherein the circumferential wall comprises a first internal thread and a distinct second internal thread, which are aligned parallel to each other and spaced from each other in an axial direction,
• a valve, comprising a hollow cylindrical housing provided with a first outer thread, which substantially corresponds to the first internal thread of the coupling piece, and with a shutter that is located in the housing and movable with respect to the housing between a closed position, in which the shutter is engaged with the housing to be substantially gas tight, and an open position, in which the shutter is at least partially positioned at a distance from the housing to allow gas to flow through the valve,
• wherein the first outer thread is configured to cooperate with the first internal thread to form a gas-tight connection between the coupling piece and the valve, and wherein the valve is located inside the interior of the coupling piece, and
• a filling piece, separate from the valve, comprising a hollow body with an inflow opening and an outflow opening, defining a gas passage between the openings, an actuator, with a movable transfer element, and a second outer thread, which substantially corresponds to the second internal thread of the coupling piece,
• wherein the second outer thread is configured to cooperate with the second internal thread to releasably connect the filling piece to the coupling piece, to form a gas-tight connection between the coupling piece and the inflow opening of the filling piece, and
• wherein the transfer element is engageable with the shutter of the valve, to transfer an actuation movement of the actuator to the shutter to move the shutter to the open position, such that the gas tank and the outflow opening of the filling piece are fluidly connected via the coupling piece, and gas can flow out of the tank and through the outflow opening to inflate a balloon.