Gas spring

A gas spring (1) comprising:

• a cup-shaped body (2);
• a movable piston (3) which is inserted in axially slidable manner in the cup-shaped body (2) and is coupled to the cup-shaped body (2) in a fluid-tight manner, so as to delimit a variable-volume closed chamber (4) adapted to contain a pressurized gas;
• and a safety plug (8) provided with a shank (12) which extends in pass-through manner in a bottom wall (10) of the cup-shaped body (2), and protrudes cantilevered within the cup-shaped body (2) so that its distal end can be reached/struck by the movable piston (3) in the case of overtravel;
• the gas spring (1) being characterized in that the shank (12) of the safety plug (8) has, inside itself, a gas discharge duct (14) which is divided into a first longitudinal segment (14a) and a second longitudinal segment (14b) by means of a breakable septum (15) that isolates/divides said longitudinal segments (14a, 14b) one from the other in a fluid-tight manner;
• wherein the second longitudinal segment (14b) of the gas discharge duct (14) ends at the distal end of said shank (12) so as to communicate directly with the closed chamber (4);
• and wherein the length of the second longitudinal segment (14b) of discharge duct (14) is shorter than that of the first longitudinal segment (14a), so that the breakable septum (15) is located close to or inside said closed chamber (4),
• wherein the breakable septum (15) is adapted to automatically break, fracture, or detach while free from contact of any structural component when the pressure difference between the two faces of the septum exceeds a predetermined limit value, and
• wherein the breakable septum (15) cracks, partially detaches or entirely breaks at least in part from a deformation at the distal end of the shank (12) when the movable piston (3), in the case of overtravel, impacts the distal end of the shank (12) without direct contact with the breakable septum (15).