Verstellbare Blende und Verfahren zu ihrer Herstellung

The invention relates to an adjustable orifice, comprising two first legs (15) which can be swivelled about their centre and two second legs (16) which are attached in movable bearings with the first legs (15) together forming a parallelogram and which bear one gap cutter (4, 5) of a pair of gap cutters, and of an operating device by means of which the shape of the parallelogram can be changed against the effect of a restoring force and thus the spacing of the gap cutters. The main feature of the invention is that the operating device consists of a piezoactuator (14) which is arranged between the first two legs (15) laterally spaced from the bearing points (13) of said legs (15), and that the adjacent first and second legs (15, 16) are interlinked by solid spring joints (11, 11'), whereby all the articulated points (11, 11', 13) of one of the first legs (15) are offset by the amount (V) compared with the articulated points of the other first leg (15) transverse to the direction of move ment (19) of the piezoactuator (14). The invention also refers to a process for the production of such an orifice.