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EP-4739926-A1 - FASTENING PINS, MULTI-PIECE FASTENERS, AND METHODS FOR FASTENING

EP4739926A1EP 4739926 A1EP4739926 A1EP 4739926A1EP-4739926-A1

Abstract

The present disclosure relates to fastening pins, multi-piece fasteners, and methods for fastening. The pin includes a first pin end, a second pin end, and a shank extending intermediate the first pin end and the second pin end. The shank includes a longitudinal axis and threads including a thread profile. The thread profile includes a first curved feature, a second curved feature, a third curved feature, a first linear feature, and a second linear feature. The first curved feature and the second curved feature form an inflection point therebetween. A radius of curvature of the second curved feature is in a range of 1.5 times greater than a radius of curvature of the third curved feature to 2.5 times greater than a radius of curvature of the third curved feature. The first linear feature has a flank angle in a range of 0 degrees to 60 degrees. degrees.

Inventors

  • PIERCE, Troy Don
  • GREEN, Marty J.
  • SMITH, JAMES THOMAS

Assignees

  • Howmet Aerospace Inc.

Dates

Publication Date
20260513
Application Date
20240531

Claims (20)

  1. 1. A fastener compri sing : a pin comprising a first pin end, a second pin end, and a shank extending intermediate the first pin end and the second pin end, the shank comprising a longitudinal axis and threads including a thread profile comprising: a first curved feature extending along the longitudinal axis and defining a first radius of curvature; a second curved feature extending along the longitudinal axis and adjacent to the first curved feature, the first curved feature and the second curved feature forming an inflection point therebetween, the second curved feature defining a second radius of curvature; a third curved feature extending along the longitudinal axis and adjacent the second curved feature, the third curved feature defining a third radius of curvature, wherein at least one of the second curved feature and the third curved feature form a root of the thread profile, wherein the second radius of curvature is in a range of 1.5 times greater than the third radius of curvature to 2.5 times greater than the third radius of curvature; a first linear feature adjacent the third curved feature and defining a flank angle in a range of 0 degrees to 60 degrees; and a second linear feature extending along the longitudinal axis and at a crest of the thread profile.
  2. 2. The fastener of claim 1, wherein the second radius of curvature is in a range of 1.8 times greater than the third radius of curvature to 2.2 times greater than the third radius of curvature.
  3. 3. The fastener of claim 1, wherein the second radius of curvature is in a range of 1.9 times greater than the third radius of curvature to 2.1 times greater than the third radius of curvature.
  4. 4. The fastener of claim 1, wherein the third radius of curvature is in a range of 0.02 inches to 0.036 inches is defined according to the following formula: R wherein a is the flank angle.
  5. 5. The fastener of claim 1, wherein the thread profile further comprises a fourth curved feature intermediate and in contact with the first linear feature and the second linear feature, the fourth curved feature defining a fourth radius of curvature in a range of greater than 0 times to 0.5 times a root depth of the thread profile.
  6. 6. The fastener of claim 1 wherein a ratio of a root depth of the thread profile to a major diameter of the threads is in a range of 0.03 to 0.06.
  7. 7. The fastener of claim 1 wherein a ratio of a thread pitch of the thread profile to a fourth distance is in a range of 4 to 6, wherein the fourth distance is defined between a first imaginary intersection of the first linear feature and the second linear feature and a second imaginary intersection of the second curved feature and the second linear feature.
  8. 8. The fastener of claim 7, wherein a ratio of the fourth distance to a major diameter of the shank is in a range of 0.02 to 0.05.
  9. 9. The fastener of claim 1 wherein the thread profile comprises a depth in a range of 0.018 inches to 0.040 inches.
  10. 10. The fastener of claim 1 wherein: the first radius of curvature is in a range of 0.015 inches to 0.035 inches; the second radius of curvature is in a range of 0.04 inches to 0.08 inches; the third radius of curvature is in a range of 0.02 inches to 0.036 inches; the first linear feature extends a distance perpendicular to the longitudinal axis in a range of 0.005 inches to 0.01 inches; the second linear feature extends a distance along the longitudinal axis in a range of 0.005 inches to 0.013 inches; the thread profile comprises a thread pitch in a range of 0.07 inches to 0.140 inches; and the shank comprises a major diameter in a range of 0.47 inches to 0.79 inches +/- 10%.
  11. 11. The fastener of claim 1 wherein: the first radius of curvature is in a range of 0.0175 inches to 0.0185 inches; the second radius of curvature is in a range of 0.042 inches to 0.046 inches; the third radius of curvature is in a range of 0.02 inches to 0.024 inches; the first linear feature extends a distance perpendicular to the longitudinal axis in a range of 0.005 inches to 0.0065 inches; the second linear feature extends a distance along the longitudinal axis in a range of 0.006 inches to 0.0075 inches; the thread profile comprises a thread pitch in a range of 0.07 inches to 0.08 inches; and the shank comprises a major diameter of 0.47 inches +/- 10%.
  12. 12. The fastener of claim 1 wherein: the first radius of curvature is in a range of 0.02 inches to 0.022 inches; the second radius of curvature is in a range of 0.048 inches to 0.052 inches; the third radius of curvature is in a range of 0.023 inches to 0.027 inches; the first linear feature extends a distance perpendicular to the longitudinal axis in a range of 0.0065 inches to 0.008 inches; the second linear feature extends a distance along the longitudinal axis in a range of 0.0075 inches to 0.009 inches; the thread profile comprises a thread pitch in a range of 0.085 inches to 0.09 inches; and the shank comprises a major diameter of 0.55 inches +/- 10%.
  13. 13. The fastener of claim 1 wherein: the first radius of curvature is in a range of 0.022 inches to 0.026 inches; the second radius of curvature is in a range of 0.055 inches to 0.06 inches; the third radius of curvature is in a range of 0.027 inches to 0.031 inches; the first linear feature extends a distance perpendicular to the longitudinal axis in a range of 0.007 inches to 0.008 inches; the second linear feature extends a distance along the longitudinal axis in a range of 0.0085 inches to 0.01 inches; the thread profile comprises a thread pitch in a range of 0.095 inches to 0.11 inches; and the shank comprises a major diameter of 0.63 inches +/- 10%.
  14. 14. The fastener of claim 1 wherein: the first radius of curvature is in a range of 0.027 inches to 0.032 inches; the second radius of curvature is in a range of 0.07 inches to 0.08 inches; the third radius of curvature is in a range of 0.033 inches to 0.038 inches; the first linear feature extends a distance perpendicular to the longitudinal axis in a range of 0.009 inches to 0.01 inches; the second linear feature extends a distance along the longitudinal axis in a range of 0.011 inches to 0.012 inches; the thread profile comprises a thread pitch in a range of 0.12 inches to 0.13 inches; and the shank comprises a major diameter of 0.79 inches +/- 10%.
  15. 15. The fastener of claim 1, wherein the shank comprises a major diameter in a range of 0.06 inch to 4 inches.
  16. 16. The fastener of claim 1, wherein the fastener comprises a metal, a metal alloy, a polymer, or a combination thereof.
  17. 17. The fastener of claim 1, further comprising a fastening collar configured to receive the pin.
  18. 18. The fastener of claim 17, wherein the fastening collar comprises a substantially smooth inner surface defining a collar cavity.
  19. 19. A method for fastening, the method comprising: inserting a pin end of the pin of the fastener of claim 17 into a bore of a structure; and forcibly contacting an elongate portion of the fastening collar of the fastener with a contact surface of an installation tool, thereby forcibly contacting the structure with a collar end of the fastening collar and deforming the elongate portion onto threads of the pin.
  20. 20. The method of claim 19, further comprising removing the fastening collar from the pin by applying a torque to the fastening collar.

Description

TITLE FASTENING PINS, MULTI-PIECE FASTENERS, AND METHODS FOR FASTENING CROSS-REFERENCE [0001] This application claims priority to U.S. Provisional Patent Application No. 63/512,320, which was filed on July 7, 2023. The contents of which is hereby incorporated by reference into this specification FIELD OF USE [0002] The present disclosure relates to fastening pins, multi-piece fasteners, and methods for fastening. BACKGROUND [0003] Vehicle frames, storage racks, solar panel sub-structures, aircraft parts, and other structures can include numerous mechanical fasteners. For example, a mechanical fastener can be installed in a bore of a structural component to secure parts together. Properly installing a mechanical fastener into a bore presents challenges. SUMMARY [0004] According to one non-limiting aspect of the present disclosure, a fastener comprising a pin is provided. The pin comprises a first pin end, a second pin end, and a shank extending intermediate the first pin end and the second pin end. The shank comprises a longitudinal axis and threads comprising a thread profile. The thread profile comprises a first curved feature, a second curved feature, a third curved feature, a first linear feature, and a second linear feature. The first curved feature extends along the longitudinal axis and defines a first radius of curvature. The second curved feature extends along the longitudinal axis and is adjacent to the first feature. The first curved feature and the second curved feature form an inflection point therebetween. The second feature defines a second radius of curvature. The third curved feature extends along the longitudinal axis and is adjacent to the second curved feature. The third curved feature defines a third radius of curvature. At least one of the second curved feature and the third curved feature form a root of the thread profile. The second radius of curvature is in a range of 1.5 times greater than the third radius of curvature to 2.5 times greater than the third radius of curvature. The first linear feature is adjacent to the third curved feature and has a flank angle in a range of 0 degrees to 60 degrees. The second linear feature extends along the longitudinal axis and is at a crest of the thread profile. [0005] According to one non-limiting aspect of the present disclosure, a method for fastening is provided. The method comprises inserting a pin end of a pin of a fastener into a bore of a structure. The fastener comprises the pin and a fastening collar. The pin comprises a first pin end, a second pin end, and a shank extending intermediate the first pin end and the second pin end. The shank comprises a longitudinal axis and threads comprising a thread profile. The thread profile comprises a first curved feature, a second curved feature, a third curved feature, a first linear feature, and a second linear feature. The first curved feature extends along the longitudinal axis and defines a first radius of curvature. The second curved feature extends along the longitudinal axis and is adjacent to the first feature. The first curved feature and the second curved feature form an inflection point therebetween. The second feature defines a second radius of curvature. The third curved feature extends along the longitudinal axis and is adjacent to the second curved feature. The third curved feature defines a third radius of curvature. At least one of the second curved feature and the third curved feature form a root of the thread profile. The second radius of curvature is in a range of 1.5 times greater than the third radius of curvature to 2.5 times greater than the third radius of curvature. The first linear feature is adjacent to the third curved feature and has a flank angle in a range of 0 degrees to 60 degrees. The second linear feature extends along the longitudinal axis and is at a crest of the thread profile. The method comprises forcibly contacting an elongate portion of the fastening collar of the fastener with a contact surface of an installation tool, thereby forcibly contacting the structure with a collar end of the fastening collar and deforming the elongate portion onto threads of the pin. [0006] It will be understood that the inventions disclosed and described in this specification are not limited to the aspects summarized in this Summary. The reader will appreciate the foregoing details, as well as others, upon considering the following detailed description of various non-limiting and non-exhaustive aspects according to this specification. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The features and advantages of the examples, and the manner of attaining them, will become more apparent, and the examples will be better understood, by reference to the following description taken in conjunction with the accompanying drawings, wherein: [0008] FIG. l is a side view of a non-limiting embodiment of a fastener according to the present disclosure; [0009] FIG. 2 is a cross-sectional view