Extraction means for producing coffee for a coffee machine

An extraction apparatus for producing coffee for a coffee machine, the apparatus comprising:

• a drive means;
• a brewing cylinder including a cylinder section for receiving coffee powder and an additional part having at least one filler opening for inserting of the coffee powder,
• wherein the cylinder section is adjustable by operation of the drive means so that the cylinder section can be reciprocably moved between predetermined positions along its axial direction,
• wherein the additional part abuts against a front side of the cylinder section in a filling position, and the additional part and the front side of the cylinder section are separated from one another in an ejecting position, thereby forming an axial gap to permit the removal of used coffee grounds;
• and
• first and second pistons that are adjustable in relation to the brewing cylinder and relative to one another,
• wherein the first piston, which is adjacent to the additional part, is disposed within the cylinder section in a brewing position, and the additional part is moveably positioned relative to the first piston such that the additional part forms a brewing chamber together with the cylinder section and the first and second pistons in the filling position.