Double-ended stud

Claim 2

A double-ended stud system including coaxially disposed stud shanks separated by an outwardly radiating generally circular rigid flange portion, a first stud shank including a helical thread formed thereon, a second stud shank including a plurality of relatively sharp crested protuberances extending fRom a root diameter, the sharp crested protuberances being of a generally uniform height along the length of the second stud shank, the flanks of adjacent protuberances being spaced at their juncture with the root diameter providing a plurality of adhesive carrying channels on the shank, a predetermined volume of heat activatable adhesive means carried on said second stud shank and encapsulating the periphery thereof filling the adhesive carrying channels to the crest diameter of the protuberances but not appreciably covering the crests of the protuberances, a recess formed on the face surface of the flange adjacent the second stud shank and extending outwardly and downwardly from the juncture of the second stud shank to a narrow outer peripheral bearing and sealing surface on the flange, the recess being substantially void of adhesive prior to insertion in a bore so that the recess may receive and sealingly retain a predetermined volume of adhesive and provide a controlled bond line beneath the flange as the second stud shank is inserted in a work structure, the face surface of the flange adjacent the first stud shank being essentially a planar surface extending generally perpendicular to the axis of the shanks so that a subsequent attachment load on the first stud section will be applied substantially to the peripheral bearing and sealing surface.

Claim 3

The stud system in accordance with claim 1, wherein the sharp crested protuberances are in the form of a spaced helical thread.

Claim 4

The stud system of claim 2, wherein the helical thread includes a first long lead thread having a plurality of convolutions and a relatively large predetermined height and being of substantially uniform size and shape throughout, a second long lead thread having a plurality of convolutions and a height substantially less than said predetermined height but greater than the root diameter and being of substantially uniform size and shape throughout, both of said threads being sharp crested, all of the threads having roots of substantially the same axial extent, the adhesive volume being sufficient to cover the crests of the second thread over a substantial axial extent of the shank and not so great as to completely cover the crests of the first thread over a substantial axial extent of the shank to provide a predetermined amount of adhesive wiped upwardly in channels formed between adjacent convolutions of the first thread as the stud is rotatively driven into a hole of less diameter than the crest diameter of the first thread.

Claim 5

The stud system of claim 1, wherein the protuberances are in the form of longitudinal splines.

Claim 6

The stud system of claim 1, wherein the protuberances on the second stud section are in the form of a spaced thread of the same hand as the thread on the first stud section.

Claim 7

A double-ended adhesive carrying stud system including a pair of coaxially arranged threaded stud sections and an integral flange positioned intermediate thereof and radiating outwardly from the axis thereof, a first stud section including a helical machine screw thread formed thereon, a second stud section having a spaced, sharp crested, helical thread formed thereon of the same hand as the thread formed on the first stud section, the helical thread including a first long lead thread having a plurality of convolutions and a relatively large predetermined height and being of substantially uniform size and shape throughout, a second long lead thread having a plurality of convolutions and a height substantially less than said predetermined height but greater than the root diameter and being of substantially uniform size and shape throughout, both of said threads being sharp crested, all of the threads having roots of substantially the same axial extent, the entering extremity of the second stud section including a recess formed therein providing a serrated cutting edge for cutting internal threads in an associated workpiece as the stud is rotatively driven therein, the flange having a gEnerally circular outer periphery and being a thin wafer-like member extending perpendicular to the axis of the stud sections, the face surface of the flange contiguous to the first section being planar while the face surface of the flange contiguous to the second section includes an annular recess extending outwardly from the juncture of the stud shank with the flange to an annular peripheral bearing and sealing portion of the flange, a predetermined volume of heat activatable adhesive carried on the second stud section and of a sufficient volume to cover the crests of the second thread over a substantial axial extent of the shank and not so great as to completely cover the crests of the first thread over a substantial axial extent of the shank, the recess being substantially void of adhesive prior to insertion within a workpiece, wherein the second stud section may be screwed into a bore in an associated workpiece which is of less diameter than the crest diameter of the thread thus permitting a portion of the volume of the heat activatable adhesive to be wiped upwardly in channels formed between adjacent convolutions of the first long lead thread of the second stud section as the stud is rotatively driven into a hole in the associated workpiece and sealed between the workpiece and the recess, providing a controlled bond line of adhesive between the flange and the workpiece as well as between the second stud section and the workpiece upon application of sufficient heat to the system.

Claim 8

A double-ended adhesive carrying stud system including a pair of coaxially arranged threaded stud sections and an integral flange positioned intermediate thereof and radiating outwardly from the axis thereof, a first stud section including a helical machine screw thread formed thereon, a second stud section having a spaced, sharp crested, helical thread formed thereon of the same hand as the thread formed on the first stud section, the helical thread including a first long lead thread having a plurality of convolutions and a relatively large predetermined height and being of substantially uniform size and shape throughout, a second long lead thread having a plurality of convolutions and a height substantially less than said predetermined height but greater than the root diameter and being of substantially uniform size and shape throughout, both of said threads being sharp crested, all of the threads having roots of substantially the same axial extent, the entering extremity of the second stud section including a recess formed therein providing a serrated cutting edge for cutting internal threads in an associated workpiece as the stud is rotatively driven therein, the flange having a gEnerally circular outer periphery and being a thin wafer-like member extending perpendicular to the axis of the stud sections, the face surface of the flange contiguous to the first section being planar while the face surface of the flange contiguous to the second section includes an annular recess extending outwardly from the juncture of the stud shank with the flange to an annular peripheral bearing and sealing portion of the flange, a predetermined volume of heat activatable adhesive carried on the second stud section and of a sufficient volume to cover the crests of the second thread over a substantial axial extent of the shank and not so great as to completely cover the crests of the first thread over a substantial axial extent of the shank, the recess being substantially void of adhesive prior to insertion within a workpiece, wherein the second stud section may be screwed into a bore in an associated workpiece which is of less diameter than the crest diameter of the thread thus permitting a portion of the volume of the heat activatable adhesive to be wiped upwardly in channels formed between adjacent convolutions of the first long lead thread of the second stud section as the stud is rotatively driven into a hole in the associated workpiece and sealed between the workpiece and the recess, providing a controlled bond line of adhesive between the flange and the workpiece as well as between the second stud section and the workpiece upon application of sufficient heat to the system.