Barrel nut with stress reduction features

Patent metadata

Field	Value
Publication number	US-9759251-B2
Application number	US-201414469640-A
Country	US
Kind code	B2
Filing date	Aug 27, 2014
Priority date	Aug 27, 2014
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A barrel nut with features for reducing tensile stresses under heavy load within the barrel nut has a partial-cylindrical body having a first planar end surface and a second planar end surface. A threaded bore extends through the partial-cylindrical body with a central axis substantially parallel to the first planar end surface and the second planar end surface. At least one groove is formed in each of the first planar end surface and the second planar end surface, the groove having a rounded surface extending at least a part of a distance between a curved upper surface of the partial-cylindrical body to a bottom surface thereof in a direction substantially parallel to the central axis of the threaded bore.

First claim

The invention claimed is:

1. A barrel nut comprising a one-piece partial-cylindrical body having a first planar end surface and a second planar end surface, a threaded bore extending through the partial-cylindrical body with a central axis substantially parallel to the first planar end surface and the second planar end surface, and at least one groove partially recessed into each of the first planar end surface and the second planar end surface extending at least a part of a length of the partial-cylindrical body in a direction substantially parallel to the central axis of the threaded bore.

2. The barrel nut of claim 1 , wherein a surface of the at least one groove is rounded.

3. The barrel nut of claim 2 , wherein a bottom surface of the partial-cylindrical body comprises a flange surrounding the threaded bore, the flange being raised above the bottom surface and extending from a circumferential edge of the threaded bore to a side edge of the bottom surface.

4. The barrel nut of claim 3 , wherein the at least one groove in each of the first planar end surface and the second planar end surface is aligned with the central axis of the threaded bore such that the at least one groove is positioned on a center line of each of the first planar end surface and the second planar end surface.

5. The barrel nut of claim 3 , wherein each of the first planar end surface and the second planar end surface comprises two grooves extending in a direction substantially parallel to the central axis from a curved upper surface to a non-curved bottom surface.

6. The barrel nut of claim 3 , wherein the flange at the side edge extends a curved upper surface of the partial-cylindrical body below the bottom surface in a central area, the central area having a length substantially equal to a diameter of the threaded bore.

7. The barrel nut of claim 1 , wherein the at least one groove in each of the first planar end surface and the second planar end surface is aligned with the central axis of the threaded bore such that the at least one groove is positioned on a center line of each of the first planar end surface and the second planar end surface.

8. The barrel nut of claim 1 , wherein the threaded bore comprises a plurality of threads extending from a bottom surface to a point below a curved upper surface of the partial-cylindrical body, a distance between the point and the curved upper surface being about 2% to about 10% of a total length of the threads.

9. The barrel nut of claim 1 , wherein the at least one groove has a rounded surface recessed into the first planar end and the second planar end of the one-piece partial-cylindrical body.

10. The barrel nut of claim 9 , wherein the rounded surface has a radius in the range of about 0.015 to 0.15 times a diameter of the barrel nut.

11. A barrel nut comprising a partial-cylindrical body having a first planar end surface and a second planar end surface, a threaded bore extending through the partial-cylindrical body with a central axis substantially parallel to the first planar end surface and the second planar end surface, each of the first planar end surface and the second planar end surface comprising two grooves extending at least a part of a length of the partial-cylindrical body in a direction substantially parallel to the central axis from a curved upper surface to a bottom surface of the partial-cylindrical body.

12. The barrel nut of claim 11 , wherein the two grooves are positioned equidistant from a center line in each of the first planar end surface and the second planar end surface, the center line being aligned with the central axis.

13. The barrel nut of claim 11 , wherein the grooves have rounded surfaces recessed into the first planar end surface and the second planar end surface of the partial cylindrical body.

14. The barrel nut of claim 13 , wherein the rounded surfaces have a radius in the range of about 0.015 to 0.15 times a diameter of the barrel nut.

15. The barrel nut of claim 13 , wherein a distance between a centerline of each of the two grooves is in the range of about 0.25 to 0.5 times a diameter of the barrel nut.

16. A barrel nut comprising a partial-cylindrical body having a first planar end surface and a second planar end surface, a threaded bore extending through the partial-cylindrical body with a central axis substantially parallel to the first planar end surface and the second planar end surface, and at least one groove in each of the first planar end surface and the second planar end surface extending at least a part of a length of the partial-cylindrical body in a direction substantially parallel to the central axis of the threaded bore, a bottom surface of the partial-cylindrical body comprising a flange surrounding the threaded bore, the flange being raised above the bottom surface and extending from a circumferential edge of the threaded bore to a side edge of the bottom surface such that a curved upper surface of the partial-cylindrical body at the side edge extends below the bottom surface in a central area.

17. The barrel nut of claim 16 , wherein the central area has a length substantially equal to a diameter of the threaded bore.

18. The barrel nut of claim 16 , wherein the at least one groove has a rounded surface recessed into the first planar end surface and the second planar end surface of the partial-cylindrical body.

19. The barrel nut of claim 18 , wherein the rounded surface has a radius in the range of about 0.015 to 0.15 times a diameter of the barrel nut.

Assignees

• Boeing Co

Inventors

• Stanescu Adrian
• Kostakis Constantine
• Butcher Michael Ronald

Classifications

• F16B31/06 Primary

  having regard to possibility of fatigue rupture · CPC title

• B23G9/006 Primary

  Slotting nuts · CPC title

• F16B37/047

  Barrel nuts · CPC title

• F16B37/04

  Devices for fastening nuts to surfaces, e.g. sheets, plates {(nuts fastened behind a wall by a toggle-mechanism F16B13/0808; threaded inserts F16B37/122; measures against loss of bolts, nuts or pins F16B41/002)} · CPC title