Then, we continued arguing that – starting from document R6 – the subject – matter of pending claim 1 is not based on an inventive step. In particular, we emphasized that also in R6 the problem which also is underlying the patent in dispute is disclosed in paragraph [0004], i.e. that the gap between the floating ring and the fixed ring may be clogged and floating ring or the fixed ring is scraped by the hard-fine particle so as to be worn, on the basis of the rotation of the floating ring or the oscillation of the movable plate. This correspond to the problem of the patent in dispute which shall overcome the wear of the movable ring. Furthermore, we emphasized that on page 10, last sentence, to page 11, first paragraph, the technical teaching of the claim of the patent in dispute is already indicated herein, namely that it is possible to either making the pitch of the screw blade smaller in the end side in place of changing the outer diameter of the screw shaft larger, or a combination thereof by making the outer diameter of the screw shaft larger and making the pitch of the screw blade smaller.