Gas spring and method of charging gas into the gas spring

A gas spring, comprising:

• a cylindrical rod member having a piston;
• a cylinder main body fitted over said rod member;
• an annular gas filling chamber, filled with compressed gas, disposed between said rod member and said cylinder main body;
• a first sealing member fitted over said rod member at one end of said gas filling chamber;
• a second sealing member fitted into said cylinder main body at the other end of said gas filling chamber;
• a stopper member, internally fitted and threadably engaged with said cylinder main body, slidably fitted over said rod member on a side opposite from said gas filling chamber in relation to said piston of said cylindrical rod member.

A gas filling method for introducing compressed gas into a gas spring, said gas spring comprising:

• a cylindrical rod member having a piston;
• a cylinder main body fitted over said rod member;
• an annular gas filling chamber, filled with compressed gas, disposed between said rod member and said cylinder main body;
• a first sealing member fitted over said piston of said cylindrical rod member at one end of said gas filling chamber;
• a second sealing member fitted into said cylinder main body at the other end of said gas filling chamber;
• a plurality of pin members disposed in an axially symmetrical fashion about said rod member;
• a plurality of slots provided in the cylinder main body;
• and
• said plurality of slots aligning with said plurality of pin members to restrict a range of movement of said rod member in relation to said cylinder main body;
• said gas filling method comprising:
• placing said gas spring in a special gas filling implement in a state in which said plurality of pin members are not yet mounted with said plurality of slots;
• moving said cylinder main body axially in relation to said rod member while said second sealing member is prevented from separating from said rod member;
• filling said gas filling chamber with compressed gas through said gas filling implement and at least one of said plurality of slots;
• moving said cylinder main body back in relation to said rod member;
• and
• locking said plurality of pin members in place.

A gas filling method for introducing compressed gas into a gas spring, said gas spring comprising:

• a cylindrical rod member having a piston;
• a cylinder main body fitted over said rod member;
• an annular gas filling chamber, filled with compressed gas, disposed between said rod member and said cylinder main body;
• a first sealing member fitted over said rod member at one end of said gas filling chamber;
• a second sealing member fitted into said cylinder main body at the other end of said gas filling chamber;
• a stopper member, internally fitted and threadably engaged with said cylinder main body, slidably fitted over said rod member on a side opposite from said gas filling chamber in relation to said piston of said cylindrical rod member;
• said gas filling method comprising:
• placing said gas spring in a special gas filling implement in a state in which said stopper member is not yet mounted;
• moving said rod member axially in relation to said cylinder main body while said first sealing member is prevented from reaching a threaded hole for said stopper member of said cylinder main body;
• filling said gas filling chamber with compressed gas through said gas filling implement and a rod insertion hole facing said second sealing member;
• moving said rod member back in relation to said cylinder main body;
• and
• mounting said stopper member.