US Patent 7377207 Device for preparing a beverage

The invention relates to a device for preparing a beverage, comprising:—a water reservoir (1);—a chamber (5) that is connected to said reservoir for delivering water;—means (17) for filling said chamber with water;—means (16) for emptying water from the chamber;—a compressed gas reservoir (2) with a three-way valve (4) for displacing said means so as to empty the chamber; and—a conduit (14) for conveying the water from the chamber to an extraction head.