Diaphragm support and a method for initial sealing in a pressure cell

A diaphragm device (80) for use in a press (40) of pressure cell type, comprising

• a diaphragm (14, 62, 88) of resilient material, such as rubber, which is adapted to form together with a press plate (54) a pressure cell for exerting a forming pressure on a workpiece in the press, characterised by
• an annular diaphragm support (12, 42, 82) which is arranged circumferentially and encloses the circumference of the diaphragm, the edge area of the diaphragm being placed in the diaphragm support.

A method for applying a pressing power in a press (40) of pressure cell type by means of a diaphragm (14, 62, 88) which is placed in a diaphragm support (12, 42, 82), characterised by the steps of

• actively exerting a force on the diaphragm support in the direction of a press plate (54) which is arranged in the press, so that an initial seal (30) is provided between the diaphragm and the press plate, and
• supplying pressure medium to the space which is enclosed by the diaphragm and the press plate while at least partly mainting said force, so that the diaphragm expands and the seal is built up, further supply of pressure medium making the diaphragm exert pressure on a workpiece which is placed therebelow.