Abstract

A device for carrying out a two-stage, linear movement as well as an associated method for displacing a displaceable structural unit relative to a stationary structural unit. A first drive unit drives a shaft, which is in operative connection with a tube, which is connected to the displaceable structural unit. If a predeterminable condition is substantially achieved, a switch is made from the first drive unit to a second drive unit. Because the tube extends through the stationary structural unit and is displaced relative to the stationary structural unit when the first drive unit is actuated, the at least one separating means being jointly displaceable with the second drive unit and coupling in a detachable manner the tube to the second drive unit initially when the condition is achieved and thereby separating the shaft from the flow of force, as soon as the second drive unit is actuated alone, the members, which transfer the rotary movement into a straight movement, can be protected in a two-stage linear movement.