Fastener for securing sheet material

Claim 2

A fastener for attaching a sheet provided with an aperture to a metal member which is positioned adjacent to the sheet and exposed through the aperture, said fastener comprising: a head which is larger than the aperture and has its forward face slightly tapered such that the periphery of that forward face is set rearwardly from the remainder of that face; a boss formed integral with the head and projected forwardly from the front face thereof, the boss having a generally cylindrical side face which is smaller in diameter than the width of the aperture and merges into the forward face of the head with the included angle between said side face and said forward face being slightly greater than a right angle, the forward face of the boss also being tapered in the same direction as the forward face of the head and at about the same angle; and an extension formed integral with the boss and projected beyond the tapered forward face of the boss, the extension being centered with respect to and substantially narrower than the boss, whereby the boss may be projected into the aperture to bring the extension against the metal member and when electrical current is passed through the fastener, the extension thereof will weld to the metal member, securing the fastener and sheet to the metal member.

Claim 3

A fastener according to claim 1 wherein said face of the boss and the tapered forward face on the heAd are covered with a dielectric substance.

Claim 4

A fastener according to claim 1 wherein the head is provided with a centrally disposed recess which opens out of the rear face thereof.

Claim 5

A fastener for attaching a sheet provided with an aperture to a metal member which is positioned adjacent to the sheet and exposed through the aperture, said fastener comprising: a circular flange-like head which is larger than the aperture and has a back face, a front face, and a centrally disposed recess of circular configuration opening out of the back face; a boss formed integral with the head and projected forwardly from the front face of the head, the boss having a generally cylindrical side face which is smaller in diameter than the aperture and is coaxial with the circular head, the forward face of the boss being tapered slightly such that its peripheral edge is set further rearwardly than the remainder of the face and the included angle between the forward face and the side face is slightly greater than a right angle; an extension formed integral with the boss and projected beyond the tapered forward face of the boss, the extension being centered with respect to and being substantially narrower than the boss; and a dielectrical material covering the side face of the boss and the adjacent front face of the flange-like head; whereby the boss may be projected into the aperture to bring the extension against the metal member and when electrical current is passed through the fastener, the extension thereof will weld to the metal member, securing the fastener and apertured sheet to the metal member.

Claim 6

A fastener for attaching a sheet provided with an aperture to a metal member which is positioned adjacent to the sheet and exposed through the aperture, said fastener comprising: a circular flange-like head which is larger than the aperture and has a back face, a front face, and a centrally disposed recess of circular configuration opening out of the back face; a boss formed integral with the head and projected forwardly from the front face of the head, the boss having a generally cylindrical side face which is smaller in diameter than the aperture and is coaxial with the circular head, the forward face of the boss being tapered slightly such that its peripheral edge is set further rearwardly than the remainder of the face and the included angle between the forward face and the side face is slightly greater than a right angle; an extension formed integral with the boss and projected beyond the tapered forward face of the boss, the extension being centered with respect to and being substantially narrower than the boss; and a dielectrical material covering the side face of the boss and the adjacent front face of the flange-like head; whereby the boss may be projected into the aperture to bring the extension against the metal member and when electrical current is passed through the fastener, the extension thereof will weld to the metal member, securing the fastener and apertured sheet to the metal member.