Self-riveting male fastener and panel assembly

Abstract

A male fastener formed of heat treated carbon steel for high performance applications, including a shank portion, radial flange and tubular barrel, wherein the barrel has an axial length of 60% or less than the outside diameter and a fastener and panel assembly, wherein the distal open end of the barrel is deformed into an L-shape and the panel is deformed by the radial flange into an L-shape having an inwardly projecting portion deformed between the radial flange and the outwardly deformed distal end of the barrel.

Description

FIELD OF THE INVENTION [0001] This invention relates to a self-riveting or self-attaching male fastener and male fastener and panel assembly for high performance applications requiring greater strength and structural integrity, wherein the male fastener, such as a stud or bolt, includes an integral tubular barrel portion which is received through an opening in the panel and riveted to the panel. BACKGROUND OF THE INVENTION [0002] U.S. Pat. No. 4,459,073 assigned to the assignee of the predecessor in interest of this application discloses an early embodiment of a self-piercing and riveting fastener of the general type disclosed herein and method of installing the male fastener in a panel. As shown in this patent, the male fastener includes a threaded shank portion, a radial flange portion integral with the shank portion and a tubular barrel portion integral with the flange portion and coaxially aligned with the shank portion. The male fastener is installed in a panel by supporting th...

AI Technical Summary

Benefits of technology

[0007] The male fastener element is installed in a panel by piercing or pre-forming an opening in the panel having a diameter generally equal to the outer diameter of the tubular barrel portion and supporting the panel on a die member or “die button” in a die press, generally the lower die platen as will be understood by those skilled in this art. However, because the barrel portion of the male fastener is shorter than a conventional male fastener of this type, the die opening is relatively shallow compared to a conventional die button for this type of installation. The die button preferably includes a concave annular surface which extends to the panel support surface and a central planar nose portion. The male fastener may be received in a conventional installation head attached to the upper die shoe of the die press which aligns the tubular barrel portion with the opening through the panel and the opening through the panel is coaxially aligned with the central nose portion. The installation head includes a reciprocating plunger which engages an annular surface of the radial flange portion and drives the male fastener toward the panel upon closing of the die press. The distal open end of the barrel portion is then driven by the plunger through the panel opening into the concave annular die surface of the die button, deforming the panel radially outwardly and the radial flange portion is driven into the panel forming an L-shaped panel portion surrounding the panel opening including a portion extending perpendicular to the planar panel having an internal surface which is deformed against the outer surface of the radial flange portion and a generally radially inwardly extending portion which is deformed between the radially outwardly extending distal end portion of the barrel portion, securely retaining the male fastener element in the panel. Where the outer surface of the radial flange portion includes circumferentially spaced radial teeth, as described above, the panel is deformed between the teeth, providing excellent torque resistance.

Problems solved by technology

However, the nut may also be unthreaded from the shank for repair or maintenance, requiring torque resistance in the opposite direction.

However, because the barrel portion of the male fastener is shorter than a conventional male fastener of this type, the die opening is relatively shallow compared to a conventional die button for this type of installation.

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