The invention relates to a Jacquard machine, comprising 2 sets of knifes moving up and down in opposition, which each, at each of their extremities, are taken up in separate knife grids (4a, 4b) being driven by a cinematic drive chain (30), and each, at one of their extremities (20a, 20b), being guided into a straight motion by means of a “Watt's linkage” rod system, the height of lift of each of these extremities (20a, 20b) of the knife grids (4a, 4b) being adjustable, and the knife grids (4a, 4b) each at their first extremities (20a, 20b) being linked with at least one first driving lever (2, 2a, 2b, 10) by means of a first linking rod (3a, 3b), and at their second extremities (21a, 21b) being linked with at least a second driving lever (2, 10) by means of a second linking rod (14a, 14b), wherein per knife grid (4a, 4b) one or several elements (1, 101, 1a, 1b, 3a, 3b) of the Watt's linkage rod system are part of the cinematic drive chain (30), and the amplitude of the motion of the said extremity (20a, 20b) of the knife grid (4a, 4b) is adjustable in the cinematic drive chain (30) before the linking point (9a, 9b) between the first rod (1, 101, 1a, 1b) and the third rod (3a, 3b) of the Watt's linkage rod system with respect to the drive motor.