US 5,707,091 A · Fastener

Abstract

A magnetic fastener has a fastening element N having a strong ferromagnetic component 20 placed on the magnetic pole 10b of the permanent magnet 10. The magnet 10 has a hole 11 extend in the direction of magnetic field. The Fastener also has an element to be attracted M having a strong ferromagnetic component 50. The ferromagnetic component 50 will be pulled to the other side 10a of the permanent magnet 10 on the fastening element N. The element to be attracted M can also be designed in such a way that the fastening element N snaps on and off through the hole 11. At least one of the ferromagnetic components 20 and 50 protrudes beyond the circumference of the permanent magnet 10 for more than 0.1 mm but no more than 2.0 mm, when the diameter of the permanent magnet is 18 mm.

Claims10

Dependent claims

In a magnetic fastener comprising

a fastening element comprising:
a substantially circular first ferromagnetic component having a first diameter O,
a substantially annular permanent magnet comprising an outer side wall having a diameter L, a central hole, and first and second end walls, first and second magnetic poles being formed on respective said first and second end walls, said permanent magnet positioned in abutment with said first ferromagnetic component, and
a case made of non-magnetic material, said case comprising a case top and a substantially cylindrical outer side wall, said case top covering said permanent magnet with one of said magnetic poles contacting an interior of said case top;
and
an attracting element comprising a second circular ferromagnetic component having a second diameter S,
the improvement wherein:
at least one of the two ratios O/L and S/L is between 9.1/9 and 11/9.

5 more elements

Dependencies are inferred from the claim text.

Fastener

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Fastener

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Abstract

Claims10