Thread-forming screw and use thereof
AssigneeArnold Umformtechnik GmbH & Co. KG
InventorBernd Werthwein
Life of this patent
Estimating the term…
Abstract
A screw having a polygonal cross section exhibits a threaded section and a forming section adjoining the threaded section and extending as far as a front rounded end of the screw and, if necessary, being free of threads. The lateral line of the forming section, if necessary free of threads, runs smoothly and without interruption from the threaded section as far as the tip at a constant curvature. The screw serves for the attachment of an element to a sheet metal component, whereby said screw engages in an existing hole in the sheet metal component and forms the thread itself. Said screw is thereby also capable of enlarging the hole and forming a raised rim hole.
Claims11
A hole-forming and thread-forming screw, having a screw head (1), which exhibits a screw driving arrangement, a screw shank (4), which exhibits a cylindrical section of thread having a retaining section (14) starting from the head of the screw and an adjoining tapping section (15), and a partially thread-free forming section (7) extending as far as a front end (8) of the screw, of which the cross section reduces continuously in the direction of the front end (8) of the screw, such that the front end (8) of the screw is rounded and configured to enlarge a pilot hole to form a raised rim hole, whereby the core cross section of the threaded section of the shank (4) of the screw exhibits, at least within the tapping section (15), the form of a polygon, especially a triangle, having rounded corners and convex sides.
Dependencies are inferred from the claim text.