Abstract An insert for installation in a hole therefor in a parent material by relative axial movement of the insert and material with or without the aid of heat, such as by high frequency vibration, wherein the insert has a series of external uniform diameter annular peripheral taper portions each tapering down towards the leading end of the insert and longitudinally serrated to provide projections for barb-like retention of the insert in the hole; and a reduced diameter pilot portion at the leading end of the insert having an external lip of substantially less diameter than that of the taper portions, which lip engages the hole in order to assist initial axial alignment and contact of the insert with the hole at the commencement of installation of the insert therein. The insert also has a rear plain external annular peripheral taper portion behind the rearmost serrated taper portion and of substantially the same diameter thereof and also tapering down towards the leading end of the insert in order to close the hole and retain parent material therein on complete installation of the insert.
An insert comprising an exterior part thereof having a series of annular peripheral taper portions, each having the same diameter and each of which tapers down from a rear shoulder thereof in a direction towards the leading end of the insert so that said taper portions are in barb-like formation, each said taper portion being longitudinally serrated with serrations of V-form at its rear part to provide a plurality of projections for retention of the insert in a hole therefor in a parent material, the serrations running out with forward reduction of each taper portion; a reduced diameter cylindrical pilot portion at the leading end of the insert; an external annular lip about the pilot portion closely adjacent the leading end of said pilot portion and axially spaced along the pilot portion from the adjacent taper portion, which lip is of taper form tapering down towards the leading end of said pilot portion and is of substantially smaller diameter than that of the said series of serrated annular peripheral taper portions for wall engagement in a said hole in order to assist in maintaining initial axial alignment and contact of the insert with the hole at the commencement of and during installation of the insert therein; and a rear plain external annular peripheral taper portion behind the rearmost serrated taper portion and of substantially the same diameter thereof and also tapering down in a direction towards the leading end of the insert in order to close a said hole and retain parent material therein on complete installation of the insert.
Claim 2
Dependent Claim
260 words
An insert comprising an exterior part thereof having a series of annular peripheral taper portions, each having the same diameter and each of which tapers down from a rear shoulder thereof in a direction towards the leading end of the insert so that said taper portions are in barb-like formation, each said taper portion being longitudinally serrated with serrations of V-form at its rear part to provide a plurality of projections for retention of the insert in a hole therefor in a parent material, the serrations running out with forward reduction of each taper portion; a reduced diameter cylindrical pilot portion at the leading end of the insert; an external annular lip about the pilot portion closely adjacent the leading end of said pilot portion and axially spaced along the pilot portion from the adjacent taper portion, which lip is of taper form tapering down towards the leading end of said pilot portion and is of substantially smaller diameter than that of the said series of serrated annular peripheral taper portions for wall engagement in a said hole in order to assist in maintaining initial axial alignment and contact of the insert with the hole at the commencement of and during installation of the insert therein; and a rear plain external annular peripheral taper portion behind the rearmost serrated taper portion and of substantially the same diameter thereof and also tapering down in a direction towards the leading end of the insert in order to close a said hole and retain parent material therein on complete installation of the insert.
Claim 3
Dependent Claim
30 words
An insert according to claim 1 wherein the said external annular lip is longitudinally serrated by continuation of the longitudinal serration of said series of serrated annular peripheral taper portions.