Anti-burr fastener

Patent metadata

Field	Value
Publication number	US-9506490-B2
Application number	US-201414499678-A
Country	US
Kind code	B2
Filing date	Sep 29, 2014
Priority date	Oct 2, 2013
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A fastener includes a cylindrical shaft located between a head and a tapered point, threads integrally extending from the shaft and extending along a portion of a length thereof, and a burr cutoff area near the tapered point and including flank surfaces therein forming an angle greater than 90° therebetween. A flattened area can be located between the flank surfaces.

First claim

What is claimed is:

1. A fastener comprising:
a shaft, a head located at a first end of the shaft, and a tapered point located at an opposite end of the shaft;
threads integrally extending from the shaft and extending along a portion of a length thereof; and
a burr cutoff area formed in the shaft adjacent to the tapered point, the burr cutoff area including flank surfaces forming an angle α of greater than 90° therebetween; and
a flattened area located between the flank surfaces.

2. The fastener of claim 1 , wherein α is from at least 90° to 145°.

3. The fastener of claim 1 , further comprising a sealing washer located on the shaft under the head.

4. The fastener of claim 1 , wherein the flank surfaces are arranged at an angle of α/2 from a center line that extends radially from the shaft through a center of the cutoff area.

5. A fastener comprising:
a shaft, a head located at a first end of the shaft, and a tapered point located at an opposite end of the shaft;
threads integrally extending from the shaft and extending along a portion of a length thereof;
a burr cutoff area formed in the shaft adjacent to the tapered point, the burr cutoff area including flank surfaces forming an angle α of greater than 90° therebetween; and
a first one of the flank surfaces is arranged at an angle α 1 of about 90° from a radial line extending from the shaft through a bottom of the burr cutoff area, and a second one of the flank surfaces is arranged at an angle α 2 of about 5° to 50° from the radial line.

6. The fastener of claim 5 , wherein the angle α 2 is about 45°.

7. A fastener of claim 5 , wherein the second one of the flank surfaces faces in an advancing direction of the thread.

8. A method of forming an anti-burr-forming fastener comprising:
providing a rotating cutting tool with a cutting surface including, in cross-section, two sides set at an angle of greater than 90° to each other that are connected by a flat portion;
applying the cutting surface to a screw in an area adjacent to a tip of the screw, cutting a groove generally parallel to an axis of the screw forming a cutoff area with two flank surfaces at an angle of greater than 90° to each other connected by a flattened area.

9. The method of claim 8 , wherein the two sides are arranged at equal angles to the flat portion.

10. A method of forming an anti-burr-forming fastener comprising:
providing a rotating cutting tool with a cutting surface including, in cross-section, two sides set at an angle of greater than 90° to each other,
applying the cutting surface to a screw in an area adjacent to a tip of the screw, cutting a groove generally parallel to an axis of the screw forming a cutoff area with two flank surfaces at an angle of greater than 90°, with one of the two sides being arranged at an angle α 1 of about 90° to a radial line extending from the shaft through a bottom of the groove, and a second one of the two sides is arranged at an angle α 2 of about 5° to 50° from the radial line.

Assignees

• Sfs Intec Holding Ag

Inventors

• Scheerer Daniel

Classifications

• F16B25/0021 Primary

  the material being metal, e.g. sheet-metal or aluminium (F16B25/0031 takes precedence) · CPC title

• F16B25/0084

  characterised by geometric details of the tip · CPC title

• F16B25/103

  by means of a drilling screw-point, i.e. with a cutting and material removing action · CPC title