| 摘要 |
PROBLEM TO BE SOLVED: To reduce slide friction in gas spring, by mooring a protrusion or steel ball to the outside of a protective member which is accommodated energized to the inside of the cylinder in an engagement hole radially located on the piston, engaging the protrusion or ball with a helical groove on the inside of the cylinder, and rotating the piston rod to extend and contract the piston rod. SOLUTION: An engagement hole 108C is located on a piston 108, which is tightened to a piston rod 1 and slidably fit to the cylinder 102. A protective member 104 which rotatably moors a steel ball 103 on the outside thereof is accommodated in this piston, energized to the inside of the cylinder by an elastic member 105. When the piston 108 is pushed against a helical groove 102A in the cylinder 102, the steel ball 103 moored by the protective member 104 fits to the helical groove 102A, and then the steel ball 103 is engaged with the helical groove 102A by the energizing force of the elastic material 105. The piston 108, of which relative position with regard to the cylinder 102 is restricted by the helical groove 102 A, moves up and down while rotating in response to the cylinder helical groove 102A.
|
