Abstract: A press for moulding concrete products has a frame, a horizontal vibrating table, a board and a mould movable vertically between a demoulding upper position and a moulding lower position. A displacing device moves and selectively rigidly connects the mould to the table during vibration of concrete in the mould in a manner whereby the mould, the board and the table form a rigid unit subjected to vibration. The connecting device includes fixing legs attached to the mould and pairs of grippers for symmetrically selectively clamping the lower ends of the fixing legs.