Lifting device for picking up a member from the bottom of the sea

1. A lifting device for picking up a member from the bottom of the sea, the lifting device comprising;

a central body extending along a central axis of the lifting device and having means for connection to a hoist cable,

a housing configured to be at least partially introduced into a cavity of the member to be picked up and accommodating at least a part of the body and wherein the body and the housing are moveable with respect to each other along the central axis of the lifting device,

an engagement member, coupled with the body and the housing such that the engagement member is moveably arranged to move in a radial direction with respect to the central axis upon movement of the body and the housing with respect to each other, wherein the engagement member ( 4 ) is moveable between a radially outward position wherein at least a part of the engagement member extends outside the housing for contacting the member to be picked up, and a radially inward position wherein the engagement member is substantially accommodated within the housing such that the lifting device can be introduced in a cavity of the member to be picked up, and

a gas spring device coupled with the body and the housing for biasing the engagement member towards its radially outward position.

2. The lifting device according to claim 1 , comprising cooperating guiding means for guiding the radial movement of the engagement member, and wherein the engagement member is coupled with the body and the housing and moveably arranged through said cooperating guiding means.

3. The lifting device according to claim 2 , wherein the cooperating guiding means comprise cooperating bevelled faces to move the engagement member by wedging action upon movement of the body and the housing with respect to each other.

4. The lifting device according to claim 2 , wherein the cooperating guiding means comprise a guide slot and a guide pin engaging the guide slot.

5. The lifting device according to claim 4 , wherein the guide slot is provided with the engagement member and the guide pin is provided with the housing.

6. The lifting device according to claim 2 , wherein the cooperating guiding means comprise a guiding surface provided with the housing for guiding the engagement member when the engagement member moves between the radially outward position and the radially inward position.

7. The lifting device according to claim 1 , wherein the engagement member is hingeably coupled with the body.

8. The lifting device according to claim 1 , comprising a plurality of engagement members arranged around the central axis for distributing a lifting force over a circumference of the lifting device.

9. The lifting device according to claim 1 , wherein the gas spring device comprises a cylinder system having a spring pressure chamber containing a compressible fluid for biasing the engagement member towards its radially outward position.

10. The lifting device according to claim 9 , wherein the spring pressure chamber is arranged at a full bore side of the cylinder system.

11. The lifting device according to claim 9 , wherein the gas spring device comprises a floating piston at an annular side of the cylinder system which floating piston delimits the spring pressure chamber, and a leaking piston facing the full bore side of the cylinder system, wherein the leaking piston is coupled with a cylinder rod.

12. The lifting device according to claim 11 , wherein the leaking piston comprises a through hole for allowing fluid to flow past the leaking piston.

13. The lifting device according to claim 12 , wherein the leaking piston and the floating piston are configured such that when the floating piston contacts the leaking piston, the floating piston closes off the through hole.

14. The lifting device according to claim 9 , wherein the cylinder system comprises a further pressure chamber opposite the spring pressure chamber, which further pressure chamber contains an hydraulic fluid for retracting the cylinder rod when pressurizing the hydraulic fluid.

15. The lifting device according to claim 9 , wherein the cylinder system is integrated in the body.

16. The lifting device according to claim 11 , wherein the body and the housing are moveable with respect to each other along the central axis of the lifting device along a housing range of motion and the cylinder rod is provided with a stop for defining an end of the housing range of movement.

17. The lifting device according to claim 1 , wherein the lifting device is one of a flange lifting tool, an internal lifting tool and an external lifting tool.