The invention refers to machines for the preparation of espresso coffee or similar beverages. A charger filter holder (1) is equipped with an elastically deformable element (5) designed to eject the block of used coffee grounds from the infusion chamber (8) after the infusion process. The charger (1) is attached by means of a bayonet fitting to the metal support sheath (2), which is maintained at a constant temperature by direct contact with the heat accumulator/exchanger (3) for the infusion water. The construction methods for the bayonet fitting reduce wear on the spiral guides (13) and make replacement of worn parts easier. The advantages are: easy ejection of the used block, constant temperature of the infusion chamber (8) and longer duration of the bayonet fitting.