Non-rotatable fastener

Claim 2

A rotation resistant threaded fastener comprising a shank portion, said shank portion including a threaded segment at one end and a generally smooth portion at the other end of said shank, said generally smooth portion comprising a tapered portion having a plurality of protuberances throughout substantially the entire axial length of said generally smooth portion with each said protuberance being arcuate throughout substantially its entire arc length and including a cross-sectional shape of a high point of maximum radial projection located between a pair of low points of minimum radial projection with said high and low points of radial projection having a progressively increasing radial length along said tapered portion from a minimum for each said minimum and maximum radial projections adjacent said threaded segment of said shank portion to a maximum at the end of said shank portion remote from said threaded segment and a plurality of protrusions of a finite axial length superimposed on said protuberances adjacent the juncture of said threaded segment and said tapered portion with each said protrusion being arcuate throughout substantially its entire arc length to follow the contour of an associated protuberance and projecting radially outwardly further than said associated protuberance at said juncture whereby when said fastener is operatively engaged within aligned apertures to fasten a plurality of workpieces together said protrusions displace material of the workpiece around the aperture in said workpieces forwardly toward said threaded shank portion and outwardly with the displaced material springing back toward its original position to pack about the protuberances on the tapered portion of said shank to resist rotation of the fastener within the workpieces.

Claim 3

A fastener unit according to claim 1 wherein the low points of adjacent protuberances are common.

Claim 4

A fastener unit according to claim 1 wherein an enlarged head is formed at that end of said shank portion opposite from said threaded portion.

Claim 5

A joint comprising a panel member having a hole extending therethrough, and a rotation resistant threaded fastener tightly seated in said hole in said panel, said fastener comprising a shank portion, said shank portion including a threaded segment at one end and a generally smooth portion comprising a tapered portion having a plurality of protuberances throughout substantially the entire axial length of said generally smooth portion with each said protuberance being arcuate throughout substantially its entire arc length and including a cross-sectional shape of a high point of maximum radial projection located between a pair of low points of minimum radial projection with said high and low points of radial projection having a progressively increasing radial length along said tapered portion from a minimum for each said minimum and maximum radial projections adjacent said threaded segment of said shank portion to a maximum at the end of said shank portion remote from said threaded segment and a plurality of protrusions of a finite axial length superimposed on said protuberances adjacent the juncture of said threaded segment and said tapered portion with each said protrusion being arcuate throughout substantially its entire arc length to follow the contour of an associated protuberance and projecting radially outwardly further than said associated protuberance at said juncture, said fastener operatively engaged within said panel member so that said protrusions displace material of the panel member around the hole in said panel member forwardly toward said threaded shank portion and outwardly with the displaced material sPringing back toward its original position to pack about the protuberances on the tapered portion of said shank to resist rotation of the fastener within the hole.

Claim 6

A joint comprising a panel member having a hole extending therethrough, and a rotation resistant threaded fastener tightly seated in said hole in said panel, said fastener comprising a shank portion, said shank portion including a threaded segment at one end and a generally smooth portion comprising a tapered portion having a plurality of protuberances throughout substantially the entire axial length of said generally smooth portion with each said protuberance being arcuate throughout substantially its entire arc length and including a cross-sectional shape of a high point of maximum radial projection located between a pair of low points of minimum radial projection with said high and low points of radial projection having a progressively increasing radial length along said tapered portion from a minimum for each said minimum and maximum radial projections adjacent said threaded segment of said shank portion to a maximum at the end of said shank portion remote from said threaded segment and a plurality of protrusions of a finite axial length superimposed on said protuberances adjacent the juncture of said threaded segment and said tapered portion with each said protrusion being arcuate throughout substantially its entire arc length to follow the contour of an associated protuberance and projecting radially outwardly further than said associated protuberance at said juncture, said fastener operatively engaged within said panel member so that said protrusions displace material of the panel member around the hole in said panel member forwardly toward said threaded shank portion and outwardly with the displaced material sPringing back toward its original position to pack about the protuberances on the tapered portion of said shank to resist rotation of the fastener within the hole.

Claim 7

A joint according to claim 4 including a second panel member adjacent the other panel member and having a hole aligned with said hole in said other panel member, said shank portion of said fastener unit extending into said hole in said second panel member with said protrusions in tightly fitted engagement with said second panel member, said material in said second panel member compressed in the vicinity of said hole in said second panel member as a result of said protrusions having greater cross-sectional dimensions than the size of said hole in said second panel member prior to installation of said fastener unit.