Patent ID: 6494656
Filing Date: 2002-12-17
Classification: B21H,F16B

Abstract:
A threaded screw for joining thin workpieces, the screw having a plurality of lead treads formed about a defined center axis and a head, in which the first workpiece overlies the second workpiece and the second workpiece defines a thin anchor material, comprising:a body section defining a multi-lobed cross section; a conical point section defining a multi-lobed cross-section; a tapered root portion located directly adjacent to the head, and the tapered root portion being between the head and the body section, the tapered root portion defining a varying cross section, the varying cross section ranging from a near circular cross section adjacent to the head to a multi-lobed cross section adjacent to the lobular body; and wherein each of the body section, the conical point section and the tapered root portion are adapted to extend from the head along the center axis through the first workpiece and through the second workpiece so that the lead threads engage the second workpiece to force it into compression against the first workpiece and the head with the tapered root portion engaging the second workpiece.