| 摘要 |
<p>An insert 11 for plastic sections is manufactured from a flat strip 31 of metal by high-speed progressive die-stamping which forms the strip into a threaded female insert. The metal strip 31 is first cut into a flat blank 32 and then thread regions 15 are impressed on the face of the strip, providing a thread pitch profile. During the stamping operation, the strip 31 is folded to form a triangular hollow tube with sharp-edged protrusions 38 extending radially outward from each corner of the triangle. A tab 21 and interlocking cutout 30 secure the abutting longitudinal side edges 23,25 of the strip 31 and ensures axial alignment of the thread regions 15. As a result of the folding and stamping process, the thread regions 15 lie along the interior wall of the tubular construction and define a thread pitch diameter which will accept the screw threaded into the center of the insert 11. The resulting triangular insert is sized so that a diameter describing the outside corners of the insert is equal to or slightly larger than the diameter of the intended receiving hole, while the barbs 38 extend to a greater diameter than the hole. A closure 53 may be included at the bottom of the insert to prevent surrounding material from entering the insert channel as the insert is installed. <IMAGE></p> |
