Kit of parts comprising a nut configured to be moved manually or driven along an external screw thread extending in a longitudinal direction

1 . A kit-of-parts, comprising:

an outer post and an inner post that are rotationally locked and extendable relative to each other in a longitudinal direction, the inner post comprising an external screw thread extending in the longitudinal direction;

a nut configured to form a mating engagement with the external screw thread of the inner post and configured to be driven along the external screw thread to selectively secure the inner post relative to the outer post in a drive mode; and

a drive comprising

a drive housing accommodating a drive motor, and

a connector configured to connect the drive housing with the nut,

wherein the nut comprises:

a housing,

a rotatable member that is rotatably arranged in the housing of the nut, said rotatable member comprising an internal screw thread that is configured to form a mating engagement with the external screw thread of the inner post, and

a transmission disposed in the housing of the nut, the transmission being configured to be connected to the drive motor, the transmission comprising an input shaft that is connectable to the drive, said transmission being configured to selectively:

rotate the rotatable member relative to the housing in the drive mode in which the transmission is driven by the drive, thereby also rotating the rotatable member relative to the external screw thread and moving the nut in the longitudinal direction along the external screw thread,

wherein the nut is further configured to be moved manually along the external screw thread extending in the longitudinal direction in a manual mode, and

the transmission is further configured to selectively: form a coupling between the housing the rotatable member in the manual mode in which the nut is manually rotated relative to the external screw thread, the coupling causing the rotatable member and the housing to jointly rotate relative to the external screw thread, thereby moving the nut in the longitudinal direction along the external screw thread.

2 . The kit-of-parts according to claim 1 , wherein, in the drive mode, the housing is rotationally locked relative to the external screw thread.

3 . The kit-of-parts according to claim 1 , wherein the transmission is irreversible.

4 . The kit-of-parts according to claim 1 , wherein the transmission comprises a self-braking gear.

5 . The kit-of-parts according to claim 1 , wherein the coupling between the housing and the rotatable member in the manual mode is provided by a gear ratio of the transmission being larger than 1:10.

6 . The kit-of-parts according to claim 1 , wherein the transmission comprises a worm drive in which a worm is rotatably disposed in said housing, and a worm wheel is at an outer circumference of the rotatable member.

7 . The kit-of-parts according to claim 1 , wherein the drive is an external drive that is releasably connectable to the housing of the nut.

8 . The kit-of-parts according to claim 1 , wherein, in the drive mode, the housing of the nut is rotationally locked relative to the outer post to prevent a relative rotation between the housing of the nut and the outer post and allow the rotatable member to be rotated relative to the housing.

9 . The kit-of-parts according to claim 1 , wherein the drive is configured to rotationally lock the housing of the nut relative to the outer post when the drive is connected to the housing of the nut.

10 . The kit-of-parts according to claim 1 , further comprising an abutment sensor that is configured to detect when the nut that is disposed on the external thread of the inner post abuts against an abutment that is associated with the outer post.

11 . The kit-of-parts according to claim 10 , further comprising:

a sensor system configured to provide at least one of:

a parameter indicative for a relative longitudinal displacement between the outer post and the nut that is disposed on the threaded inner post, and

a parameter indicative for a compressive force between the outer post and the nut that is arranged on the threaded inner post,

wherein the abutment sensor is configured to detect the parameter of the sensing system.

12 . The kit-of-parts according to claim 11 , wherein the sensing system comprises:

an inner ring and an outer ring, one of the inner ring and the outer ring being connected to the outer post, the other of the inner ring and the outer ring defining the abutment that is associated with the outer post,

a guide configured to restrict a relative rotation between the inner ring and the outer ring and allow the inner ring and the outer ring to slide relative to each other in a longitudinal direction over a predetermined sliding distance, and

a pretensioner configured to urge the inner ring and the outer ring away from each other.

13 . The kit-of-parts according to claim 11 , wherein the outer ring is connected to the outer post, and

the inner ring is longitudinally moveable relative to the outer ring and defines the abutment associated with the outer post.

14 . The kit-of-parts according to claim 13 , wherein the drive is configured to rotationally lock the housing of the nut relative to the outer ring that is connected to the outer post when the drive is connected to the housing of the nut.

15 . The kit-of-parts according to claim 10 , further comprising a controller configured to control the drive to selectively drive the transmission and thereby move the nut in the longitudinal direction along the external screw thread.

16 . The kit-of-parts according to claim 15 , wherein the controller is configured to control the drive depending on a signal received from the abutment sensor.

17 . The kit-of-parts according to claim 15 , wherein the controller is configured to control the drive depending on at least one of:

a sensor signal obtained from the abutment sensor, and

the parameter provided by the sensing system.

18 . The kit-of-parts according to claim 17 , wherein the controller is configured to move the nut in the longitudinal direction along the external screw thread towards the outer post when the inner post extends relative to the outer post to thereby reinstate a secure connection between the inner post and the outer post.

19 . The kit-of-parts according to claim 17 , wherein the controller is configured to move the nut a distance in the longitudinal direction along the external screw thread away from the outer post to allow the inner post to securely retract said distance into the outer post before a secure connection between the inner post and the outer post is reinstated.

20 . The kit-of-parts according to claim 1 , further comprising an external power source that is connectable to the drive and configured to provide power to drive the drive motor.

21 . The kit-of-parts according to claim 1 , wherein the outer post and the inner post are members of a strut, and

the nut is a securing nut configured to selectively secure the inner post relative to the outer post.