Eccentric 1 rotates about fixed axis A. Connecting rod 4 of four-bar linkage ABCE has collar b encircling eccentric 1. Link 3 is connected by turning pairs C and D to rocker arm 5 and slider 2 which moves along fixed guides p-p. When eccentric 1 rotates about axis A, slider 2 (the press slide), reciprocates. The position of the stroke of slider 2 is adjusted by screw device a.