Linear motion damping device

A linear motion damping device comprising:

• a cylindrical body provided therein with a receiving compartment and an axial hole in communication with two ends of said receiving compartment;
• a dragging rod provided with a threaded portion and located in said axial hole and said receiving compartment such that said dragging rod is caused to slide along an axial direction of said dragging rod;
• a fastening member engaged with said threaded portion of said dragging rod such that said fastening member is located in said receiving compartment, and that said fastening member turns around said dragging rod at the time when said dragging rod is exerted on by an axially-oriented external force, thereby providing said dragging rod with a damping force against said dragging rod at the time when said dragging rod is engaged in a displacement along an axial direction thereof;
• said two ends of said receiving compartment and said axial hole having a connection place with a first stepped surface and a second stepped surface;
• said fastening member having a first end surface and a second end surface wherein said first end surface comes in contact with said first stepped surface at the time when said dragging rod is exerted on by an axially-oriented push force and wherein said second end surface comes in contact with said second stepped surface at the time when said dragging rod is exerted on by an axially-oriented pull force;
• wherein said first end surface and said first stepped surface have a contact area;
• and wherein said second end surface and said second stepped surface have a contact area unequal to said contact area of said first end surface and said first stepped surface.