Research Engineering & Manufacturing, Inc.

Conti Fasteners Ag

Conti Fasteners

John R Reynolds

Alan Pritchard

Edmund A Hebert

Kenneth J Gomes

Dennis O Boyer

Bobby Lee Budziszek

Donald A Fosmoen

Benjamin M Fosmoen

A combined thread forming and thread locking fastener is disclosed. A fastener includes three thread zones. A first thread zone utilizes a first thread forming thread profile with an increasing outer diameter. A second thread zone extends from the end of the first zone utilizing the first thread forming thread profile and continues with a constant diameter. The third thread zone utilizes a thread locking thread profile continuing along substantially the remainder of the shaft of a fastener.

Thread forming and thread locking fastener

A self-tapping fastener is provided. The fastener is formed from a blank having an odd number of lobes along a cross section taken perpendicular to its axis of rotation. The lobes define a relatively high out-of-round cross section along a tapered thread-forming zone, and a relatively low out-of-round cross section along the main body taken in a direction toward the drive head. Between the main body and tapered thread-forming zone is located an additional thread forming zone having an axial length of approximately one thread pitch and a cross section that conforms to the high out-of-round of the tapered zone. The maximum diameter (at the lobes) of the additional thread-forming section approximately matches that of the full-diameter main body section. A lower-diameter stabilizing section can be provided ahead of the tapered zone, adjacent the tip of the fastener.

Self-tapping fastener

A blank for a self tapping fastener, and corresponding fastener is provided. The blank defines an odd number of lobes along a cross section taken perpendicular to its axis of rotation. The lobes define a relatively high out-of-round cross section along a tapered thread-forming zone, and a relatively low out-of-round cross section along the main body taken in a direction toward the drive head. Between the main body and tapered thread-forming zone is located an additional thread forming zone having an axial length of approximately one thread pitch and a cross section that conforms to the high out-of-round of the tapered zone. The maximum diameter (at the lobes) of the additional thread-forming section approximately matches that of the full-diameter main body section. A lower-diameter stabilizing section can be provided ahead of the tapered zone, adjacent the tip of the fastener.

Blank for self-tapping fastener

A header die for forming a self-tapping fastener blank provides die forming zones within which the blank is formed, the blank therby defining an odd number of lobes along a cross section taken perpendicular to its axis of rotation. The lobes define a relatively high out-of-round cross section along a tapered thread-forming zone, and a relatively low out-of-round cross section along the main body taken in a direction toward the drive head. Between the main body and tapered thread-forming zone is located an additional thread forming zone having an axial length of approximately one thread pitch and a cross section that conforms to the high out-of-round of the tapered zone. The maximum diameter (at the lobes) of the additional thread-forming section approximately matches that of the full-diameter main body section. A lower-diameter stabilizing section can be provided ahead of the tapered zone, adjacent the tip of the fastener.

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South Dartmouth, MA, United States of America

John R Reynolds