| 摘要 |
A coffee mill comprising a vertical screw of generally cylindrical form, provided with at least one helical groove and mounted to cooperate with a truncated conical crushing chamber having a section decreasing towards a cylindrical bore at the lower end of the chamber, which section serves to guide the lower part of the said screw, said groove having a pitch which decreases progressively towards its lower end, and a depth which decreases progressively towards its lower end. |
