Linear actuator and telescopic column with double threaded spindel

A linear actuator for height adjustable columns comprising a threaded spindle with a longitudinal extension along a longitudinal axis, the spindle being adapted to be rotated by a driving shaft, wherein the spindle is provided with a right-hand thread at a first portion of the longitudinal extension and a left-hand thread at a second portion of the longitudinal extension, the linear actuator further comprising:

• a right-hand threaded nut member in threaded connection with the right-hand thread of the spindle;
• and
• a left-hand threaded nut member in threaded connection with the left-hand thread of the spindle;
• wherein the right-hand threaded nut member comprises a first and a second part configured to be in threaded connection with the spindle on opposing sides along the circumference of the spindle;
• wherein the left-hand threaded nut member comprises a first and a second part configured to be in threaded connection with the spindle on opposing sides along the circumference of the spindle;
• wherein, in at least a contracted state of the linear actuator, the right-hand threaded nut member and the left-hand threaded nut member extend along the same portion of the longitudinal extension of the spindle;
• and
• wherein the threaded connection of the right-hand and left-hand threaded nut member to the spindle provides opposite linear movement of the right-hand threaded nut member relative the left-hand threaded nut member along the longitudinal axis when the spindle is rotated.