Patent ID: 6988863
Filing Date: 2006-01-24
Classification: F16B

Abstract:
1. A fastener, comprising a head and an elongated body extending in an axial direction thereof downwardly from said head; said elongated body comprising, in said axial direction, a first enlarged portion connected to an underside of said head via a first neck portion having a cylindrical perimeter, and a second enlarged portion connected to said first enlarged portion via a second neck portion having a cylindrical perimeter which is smaller than that of the first neck portion, whereby sheet materials having openings can be accommodated around said neck portions between said first enlarged portion and said head and between said first and second enlarged portions; each of said enlarged portions being rigidly formed with said elongated body so as to not be radially deformable relative thereto and having a maximum dimension and a minimum dimension respectively in first and second radial directions perpendicular to said axial direction; wherein the dimensions of said enlarged portions in said first and second radial directions are not greater than respective dimensions of said head in said first and second radial directions; and wherein each of said enlarged portions has the maximum dimension and the minimum dimension respectively in the same first and second radial directions which are perpendicular to each other.