Floating fastener with shock-absorbing structure

1. A floating fastener with shock-absorbing structure, comprising:

a base comprising a cylindrical portion, an accommodating space formed through said cylindrical portion, a protruding abutment ring and an inner ring provided on an inner wall of said cylindrical portion, and a bottom plate extending outwards from a bottom side of said cylindrical portion;

a fixing element comprising a head, a shank extending downwards from said head and passing through said accommodating space of said base, a locking portion extending downwards from said shank, and a stop portion located on a top side of said locking portion around said shank for stopping against a bottom side of said inner ring;

a flexible liner attached with a bottom surface thereof to a top surface of said bottom plate, said flexible liner comprising a perforation placed outside said cylindrical portion of said base and a positioning embedding portion protruding upwards from a top side thereof around said perforation of said flexible liner and placed in a first fixing hole of a preset first plate;

a positioning tube comprising a tube body formed with a perforation through the inside and a protruding ring portion expanding outward from a bottom side of said tube body; and

a buffer pad comprising a perforation inside and a ring groove set in an inner wall thereof and positioned on said protruding ring portion of said positioning tube;

wherein the assembly structure of said positioning tube and said buffer pad is placed outside said cylindrical portion of said base through said perforation of said positioning tube from top to bottom to form a positioning; said buffer pad and said flexible liner are flexibly supported on opposing upper and lower surfaces of said preset first plate respectively, so as to absorb and buffer the stress transmitted to said preset first plate when the floating fastener vibrates.

2. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein said accommodating space of said base is approximately in three stages with different apertures, the aperture from the topmost edge of said cylindrical portion to said abutment ring is the largest, the aperture from the bottom of said base to said inner ring is next, and the aperture between said abutment ring and said inner ring is the smallest.

3. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein said cylindrical portion of said base has a flange formed on a top side thereof and expanding downwards, and a bevel angle formed on a top side of said flange; said positioning tube further comprises a tapered wall surface formed on an inner wall of said tube body and said protruding ring portion, the thickness of said tapered wall surface gradually shrinking from top to bottom, so that when the assembly structure of said positioning tube and said buffer pad is placed outside said cylindrical portion of said base through said perforation of said positioning tube from top to bottom, said tapered wall surface slides down along said bevel angle to let a bottom side of said buffer pad abut against the upper surface of said preset first plate, so that a supporting portion on a top side of said tube body of said positioning tube pushes up against a bottom side of said flange to form a positioning.

4. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein said bottom plate of said base has an abutment surface attached to an upper surface of a preset second plate, said preset second plate having a second fixing hole for locking and fixing said locking portion of said fixing element, said second fixing hole having an inner wall thereof provided with an internal thread; said locking portion of said fixing element is provided with an external thread for engagement with said internal thread of said second fixing hole of said preset second plate.

5. The floating fastener with shock-absorbing structure as claimed in claim 1 , further comprising an elastic member sleeved on said shank and set between a bottom side of said head of said fixing element and said abutment ring of said base.

6. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein said head of said fixing element has a top surface thereof provided with an actuating groove for locking or unlocking a preset hand tool, and said actuating groove refers to a groove in the shape of a straight line, a cross, a hexagon or a plum blossom shape.

7. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein the aperture of said perforation of said positioning tube is smaller than the aperture of said perforation of said buffer pad.

8. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein said flexible liner is a one-piece structure selectively made of silicone, plastic or rubber.

9. The floating fastener with shock-absorbing structure as claimed in claim 1 , wherein said buffer pad is a one-piece structure selectively made of silicone, plastic or rubber.