In a press having a plunger supported so as to be movable linearly back
and forth by drive means which include at least one servomotor in
combination with a rotatably supported inertia structure connected for
rotation with the servomotor, the inertia structure has an inertia moment
which is small enough to permit reversal of the servomotor within a
stroke length of the plunger so that the stroke of the plunger is
adjustable under the control of a control device connected to the
servomotor for controlling its operation.