The invention relates to an apparatus for preparing coffee, comprising a holder provided with an access opening for placing a product to be extracted into said holder; a cover for closing and releasing the access opening; clamping means for pressing the holder and cover towards each other when the cover closes off the access opening of the holder and closing means for retaining the cover and the clamping means in position when the cover closes off the access opening of the holder.
Such an apparatus is known from EP 0 904 718. In this known apparatus the holder is mounted in a first housing part and the cover is spring adjustably mounted in a second housing part. To close the apparatus, the second housing part is pivoted towards the first housing part, whereupon the spring will adjust the orientation of the cover so that it can properly engage the holder. Due to this adjustment, clamping means at the inner side of the second housing part engage clamping means at the outer side of the cover, thus establishing a clamping force which presses the cover onto the holder. Subsequently, a clip on the second housing part can be hooked behind a protrusion of the first housing part, to retain the cover and clamping means in the closed position.
A disadvantage of this known apparatus is that the spring and clamping means allow the cover to become misaligned during closure, without a user noticing. The misalignment can for instance be prompted due to a pouch or other filter structure or coffee granulate being misplaced and getting caught between the edges of the cover and the holder or due to too many pouches having been placed in the holder. Due to such misalignment no proper seal will be attained between the holder and cover and consequently, in use, the pressure in the holder will be too low, affecting the quality of the brew.