Apparatus for fixing pressure vessel

1. An apparatus for fixing a pressure vessel to a subject, the apparatus comprising:

a frame part disposed separably from the subject and configured to support the pressure vessel; and

a lifting device configured to selectively raise or lower the frame part between a first position with a first height and a second position with a second height lower than the first height with respect to the subject,

wherein the lifting device comprises:

a lifting table on which the frame part is seated;

a connection link member having one end rotatably connected to the lifting table and the other end rotatably connected to the subject; and

a stretchable part selectively stretchable and configured to connect the lifting table and the subject, and

wherein the lifting table is raised or lowered between the first position and the second position depending on a change in length of the stretchable part.

2. The apparatus of claim 1 , wherein the stretchable part comprises a cylinder having one end connected to the lifting table and the other end connected to the subject, the cylinder having a selectively variable length.

3. The apparatus of claim 2 , comprising:

a rectilinearly movable member configured to rectilinearly move relative to the subject depending on a change in length of the cylinder; and

a guide link member having one end rotatably connected to the lifting table and the other end rotatably connected to the rectilinearly movable member.

4. The apparatus of claim 1 , comprising:

a lifting guide part configured to guide the raising or lowering of the frame part relative to the subject,

wherein the lifting guide part comprises:

a lifting guide member disposed on the subject and having a guide slot; and

a guide protrusion disposed on the frame part and accommodated in the guide slot so as to be movable along the guide slot.

5. The apparatus of claim 1 , comprising:

a rolling member provided in the lifting device so as to be in rollable contact with the frame part.

6. The apparatus of claim 5 , comprising:

an accommodation portion disposed on the frame part, and configured to selectively accommodate the rolling member so as to restrict a rolling motion of the rolling member relative to the frame part is restricted.

7. The apparatus of claim 5 , comprising:

a guide member provided in the lifting device and configured to guide a rolling motion of the rolling member relative to the frame part.

8. The apparatus of claim 1 , comprising:

a rolling member disposed on the frame part so as to be in rollable contact with the lifting device.

9. The apparatus of claim 8 , comprising:

an accommodation portion provided in the lifting device, and configured to selectively accommodate the rolling member so as to restrict a rolling motion of the rolling member relative to the lifting device.

10. An apparatus for fixing a pressure vessel to a subject, the apparatus comprising:

a frame part disposed separably from the subject and configured to support the pressure vessel; and

a lifting device configured to selectively raise or lower the frame part relative to the subject,

wherein the frame part comprises:

a first frame member; and

a second frame member disposed individually and separably from the first frame member, and

wherein the apparatus further comprises another pressure vessel, and the pressure vessel and the another pressure vessel are respectively provided in the first frame member and the second frame member.

11. The apparatus of claim 10 , wherein the second frame member is stacked on an upper portion of the first frame member.

12. The apparatus of claim 11 , comprising:

a lower rolling member disposed on the first frame member so as to be in rollable contact with the second frame member.

13. The apparatus of claim 12 , comprising:

an upper accommodation portion disposed on the second frame member, and configured to selectively accommodate the lower rolling member so as to restrict a rolling motion of the lower rolling member relative to the second frame member.

14. The apparatus of claim 12 , comprising:

a support bracket disposed on the first frame member and configured to support the lower rolling member so that the lower rolling member is rotatable.

15. The apparatus of claim 14 , comprising:

a guide partition wall extending from the support bracket and configured to guide a rolling motion of the lower rolling member relative to the second frame member.

16. The apparatus of claim 12 , comprising:

a partition wall member disposed on the first frame member and configured to guide a rolling motion of the lower rolling member relative to the second frame member.

17. The apparatus of claim 11 , comprising:

an upper rolling member disposed on the second frame member so as to be in rollable contact with the first frame member.

18. The apparatus of claim 17 , comprising:

a lower accommodation portion disposed on the first frame member, and configured to selectively accommodate the upper rolling member so as to restrict a rolling motion of the upper rolling member relative to the first frame member.