... the cover on the Greek surface, removing Greece from the outside of the Greek pump.

摘要

The purpose of this study is to prevent the penetration of foreign bodies in Greece. The Greek surface cover buried in the pump during extraction was wiped clean,It is slightly larger than the interior diameter of the whole (5),The outer cover (1) with a thickness thinner than the center penetrates the central through hole (1a) and the small through hole (1b),The annular bodies (2) (3) with elastic wings (2a) (3a) are respectively fixed on the common (1a) (1b).