Patent ID: 8011291

Claim:
A machine for preparing an infusion, comprising: an infusion chamber ( 14 ) that is designed to receive a product to be infused and that is delimited by a lower vat ( 3 ) and an upper tamping head ( 6 ) that moves relative to the lower vat ( 3 ); and a supply of pressurized hot water to the infusion chamber ( 14 ), wherein said tamping head ( 6 ) comprises an internal tube ( 26 ) that has an inlet ( 27 ) that communicates with the infusion chamber ( 14 ) and that makes possible passage of the infusion through the tamping head ( 6 ) in an upward direction toward a distribution outlet, and means ( 30 ) that are located in said internal tube ( 26 ) close to its inlet ( 27 ) and suitable for forming foam in the infusion during its passage through the tamping head ( 6 ) and for preventing the infusion from returning into said infusion chamber ( 14 ), and said means are formed by a deformable flexible part ( 30 ) that is pierced by at least one calibrated orifice ( 35 ) to form the foam and to keep the infusion from returning.