摘要 |
A press diaphragm for pressing china plates etc. has an edge part designed to be forced inwards on pressing and then to be moved back outwards on letting off the pressure clear of the plate edge. To this end the diaphragm has an edge part, acted upon by a downwardly moving keeper, and has a groove in its upper face. Under the groove the diaphragm is acted upon by hydraulic pressure more than at other positions. |