Patent ID: 7849756

Claim:
A linear drive for adjusting at least one movable structure, comprising: an outer tube; at least one spindle drive having a rotatable spindle and defined by an axis; a lifting nut disposed on the spindle and engaging the outer tube to prevent rotation, said lifting nut being linked to a movable structure; and at least one safety mechanism disposed on the spindle at an axial distance to the lifting nut and engaging the outer tube to prevent rotation so that the safety mechanism and the lifting nut are movable in a direction of the axis along the spindle and along the outer tube, said safety mechanism including an inner nut attached to the spindle and an outer guide bushing attached onto the inner nut, wherein the inner nut and the guide bushing have an engagement structure which effects a form-fitting engagement between the inner nut and the guide bushing during normal operation and is so constructed as to effect a disengagement between the inner nut and the guide bushing, when the safety mechanism is subjected to a predefined load torque.