Magnetic fastener

Claim 1

A two part magnetic closure device, which comprises: a) a magnetically attractive first element including: i.) a magnet member having a central axial bore and having first and second axial ends with first and second opposite polarities respectively, wherein the average distance between said first and second axial ends is at least two millimeters, and wherein an outer peripheral surface of said magnet is defined by a side wall, and wherein said side wall is at least two millimeters in height; ii.) an annular cover member formed of non-ferromagnetic material, and having a flat upper surface which covers said first axial end of said magnet, said annular cover member having a peripheral wall portion monolithically formed therewith and disposed around said magnet to surround at least a portion of said side wall of said magnet, said annular cover member having an angled or curved portion located at the joining of said peripheral wall and an outer edge of said flat upper surface of said annular cover member, wherein said angled or curved portion of said cover member maintains said magnet in a fixed location relative to said cover member, said annular cover member defining an aperture therethrough, said aperture being smaller than said axial bore of said magnet, said aperture being aligned with and held in a fixed relationship with said central axial bore of said magnet by the interaction of said angled or curved portion of said annular cover member and a peripheral edge of said first axial end of said magnet; and iii.) a first ferromagnetic plate having a portion adjacent said second axial end of said magnet, a first ferromagnetic protrusion extending upward from said first ferromagnetic plate into said central axial bore of said magnet, and a peripheral wall portion monolithically formed therefrom and disposed around said magnet, said peripheral wall portion extending in an upward direction from said first ferromagnetic plate toward said first axial end of said magnet adjacent, but not in contact with, said side wall of said magnet and with at least one portion of an upper edge of said peripheral wall portion of said first ferromagnetic plate defining at least one fixed elevation around a perimeter of said side wall of said magnet, and connecting with and being held in a fixed relationship with said annular cover member, said peripheral wall portion having a thickness greater than the thickness of said annular cover member, said first ferromagnetic plate having attachment means affixed thereto for attaching said magnetically attractive first element to an object; and b) a magnetically attractable second element including a second ferromagnetic plate positionable adjacent said annular cover member and said first axial end of said magnet, a second ferromagnetic protrusion fixedly attached to and extending downward from said second ferromagnetic plate, said second ferromagnetic protrusion being dimensioned to be positioned within and received by said aperture in said annular cover member and being spaced apart from an inner wall of said central axial bore of said magnet, said second ferromagnetic protrusion dimensioned to make contact with said first ferromagnetic protrusion extending upward into said central axial bore of said magnet from said first ferromagnetic plate attached to said second axial end of said magnet, said annular cover member and said second ferromagnetic plate member being maintained in a spaced relationship of about 0.005 to about 0.05 millimeters by said second ferromagnetic protrusion on said second ferromagnetic plate of said second element, said spaced relationship being maintained to prevent abrasive contact between said flat upper surface of said annular cover member and said magnetically attractable second element when said first magnetically attractive member and said second magnetically attractable member are engaged one with the other in a closed position, said magnetically attractable second element having attachment means affixed thereto for attaching said magnetically attractable second element to an object.