Apparatus with pressurised gas supply for preparing beverages

Liquid pumping device for supplying pressurized liquid to a beverage distribution apparatus comprising:

• a body comprising a gas supply inlet,
• a chamber for receiving the liquid,
• a liquid inlet communicating with the chamber,
• a liquid outlet communicating with the chamber from which the liquid is expelled under a certain pressure,
• the chamber being bounded by at least one elastic wall separating the liquid from the gas supply in a sealed manner;
• the wall being configured to deform elastically and thereby reduce the internal volume of the chamber under the effect of a gas thrust against the wall, the reduction in volume of the chamber driving the liquid through the liquid outlet,
• the device is so constructed and arranged to be filled by a suction created by the wall which has a sufficient elasticity enabling it to return to position when the gas stops deforming the wall and to create a vacuum in the chamber in order to suck the liquid into the chamber through the liquid inlet and thereby to fill the chamber with liquid, the device comprising closure means for retaining a constant volume of sucked liquid in the chamber up to its forced expulsion by the wall under the effect of the gas pressure.

Apparatus for preparing beverages comprising:

• a module;
• a supply of gas to pressurize a liquid;
• a chamber communicating with the gas supply to pressurize the liquid in the chamber and to distribute a quantity of liquid under a certain pressure through the module, the chamber comprising at least one elastic wall, separating the gas from the liquid in a sealed manner and, the wall deforming elastically and reducing the volume of liquid in the chamber, and
• a feed tank for filling the chamber with liquid, the chamber having a smaller capacity than the tank, and communicating with the tank so as to be filled with liquid by a suction effect created when a gas stops compressing the wall and when the wall returns to an initial position.