BACK-OUT RESISTANT FASTENER

• US 20150071731A1
• Filed: 09/09/2014
• Published: 03/12/2015
• Est. Priority Date: 09/11/2013
• Status: Active Grant

• Current Assignee: SFS Group AG
• Original Assignee: SFS Intec Holding AG (SFS Group AG)
• Inventors: Scheerer, Daniel
• Granted Patent: US 9,611,882 B2
• Time in Patent Office: Days
• US Class Current: 411/353
• CPC Class Codes: F16B 25/0021 the material being metal, e.g. sheet-metal or aluminium F16B25/0031 takes precedence
• CPC Class Codes: F16B 25/0078 with a shaft of non-circular cross-section or other special geometric features of the shaft
• CPC Class Codes: F16B 25/103 by means of a drilling screw-point, i.e. with a cutting and material removing action
• CPC Class Codes: F16B 43/001 for sealing or insulation

Abstract

A fastener is provided having a cylindrical shaft with a generally constant diameter located between a head and a tapered point. The fastener has a thread integrally extending from the shaft and extending along a portion of a length thereof that terminates at an end of the shaft proximate the head with a back-out discontinuity. At least one ring integrally extends from the shaft in an area of the shaft between the back-out discontinuity and the head. The at least one ring has an outside diameter that is less than an outside diameter of the thread.

Claims

1. A fastener comprising:

a cylindrical shaft located between a head and a tapered point;

a thread integrally extending from the shaft and extending along a portion of a length thereof that terminates at an end of the shaft proximate the head with a back-out discontinuity; and

at least one ring having an outside diameter that is less than an outside diameter of the thread integrally extending from the shaft in an area of the shaft having no threads between the back-out discontinuity and the head.

2. The fastener of claim 1, wherein the back-out discontinuity is formed by an abrupt thread termination at an angle approximately perpendicular to the shaft.

3. The fastener of claim 2, wherein the abrupt thread termination forms a radial edge or face.

4. The fastener of claim 1, wherein the at least one ring is formed as a radius in cross-sectional profile extending out from the shaft.

5. The fastener of claim 1, wherein an outside diameter of the ring is at least about 5% greater than an outside of the shaft.

6. The fastener of claim 1, wherein the ring has a height projecting beyond the shaft that is approximately 25% of a thread height of the thread.

7. The fastener of claim 1, wherein the back-out discontinuity is formed by a taper and change in pitch of a last portion of the thread to a point of self-intersection.

8. The fastener of claim 7, wherein at the point of self-intersection, the last portion of the thread terminates approximately perpendicular to the shaft into an adjacent thread wall at a diameter less than a thread outer diameter.

9. The fastener of claim 7, wherein the fastener has a self-drilling tip.

10. A threaded connection including the fastener of claim 1, further comprising a sheet and a substrate, the outside diameter of the at least one ring is greater than a diameter of a hole formed in the sheet connected to the substrate, with the at least one ring forming a seal against an inner periphery of the hole by a press fit.