Witness enabled fasteners and related systems and methods

Patent metadata

Field	Value
Publication number	US-9677592-B2
Application number	US-201414531835-A
Country	US
Kind code	B2
Filing date	Nov 3, 2014
Priority date	Nov 3, 2014
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A fastening device may include a first member configured for forceful engagement with a second member. The first member may include a sensor configured to emit at least a first photo-luminescent signal to a detector when at least a predetermined first torque level is applied to the first member when the first and second members are engaged.

First claim

What is claimed is:

1. A system comprising:
a fastening device including a first member configured for forceful engagement with a second member, the first member including a sensor configured to emit a first photo-luminescent signal indicating at least a first level of torque applied to the first member when the first and second members are engaged, wherein the first member is a washer having a surface that is coated with the sensor, the washer contacting a surface of the second member when the washer and the second member are engaged; and
an inspection device configured to receive the first photo-luminescent signal from the sensor.

2. The system of claim 1 , wherein the inspection device is configured to determine the first level of torque by comparing spectral information included in the first photo-luminescent signal against a standard.

3. The system of claim 1 , wherein the inspection device is configured to determine whether the first level of torque has been reached based at least in part on reception of the first photo-luminescent signal.

4. The system of claim 3 , wherein the first level of torque corresponds with a desired level of torque for forceful engagement of the first member with the second member, the sensor being further configured to emit a second photo-luminescent signal indicating that torque applied to the first member has exceeded the first level by at least a threshold amount of torque, and the inspection device being further configured to determine whether torque applied to the first member has exceeded the first level by at least the threshold amount of torque based at least in part on reception of the second photo-luminescent signal.

5. The system of claim 1 , wherein the inspection device includes an emitter and a detector, the emitter being configured to emit electromagnetic radiation toward the sensor, the sensor being configured to emit the first photo-luminescent signal in response to absorption of the electromagnetic radiation from the emitter, the detector being configured to receive the first photo-luminescent signal from the sensor.

6. The fastening device of claim 1 , wherein the characterizing wavelength of a first photon corresponds to a wavelength of light that is non-visible to an unaided human eye.

7. The fastening device of claim 1 , wherein the sensor is configured to emit a second photo-luminescent signal indicating when a predetermined second torque level is applied to the first member when the first and second members are engaged, the second torque level being greater than the first torque level, the sensor being further configured to emit a third photo-luminescent signal indicating when a predetermined third torque level is applied to the first member when the first and second members are engaged, the third torque level being less than the first torque level.

8. The fastening device of claim 1 , wherein the second member is an object having an aperture for receiving the first member.

9. The fastening device of claim 1 , wherein the detector includes a human eye.

10. The fastening device of claim 1 , wherein the detector includes an electronic photo-detector configured to receive the first photo-luminescent signal, to generate a second signal based on and indicative of the first photo-luminescent signal, and to output the second signal to a user.

11. The fastening device of claim 1 , wherein the first torque level is at least 3 foot-pounds.

Assignees

• Boeing Co

Inventors

• Bernhardt Roger D

Classifications

• G01L5/243

  using washers · CPC title

• G01L5/0004

  Force transducers adapted for mounting in a bore of the force receiving structure (G01L5/0009 takes precedence) · CPC title

• F16B31/02 Primary

  for indicating {the attainment of a particular tensile load} or limiting tensile load {(apparatus for, or method of, determining value of torque or twisting moment for tightening a nut or other member similarly stressed G01L5/24)} · CPC title

• G01N2021/6439

  with indicators, stains, dyes, tags, labels, marks · CPC title

• G01L1/24

  by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis {using infrared, visible light, ultraviolet} · CPC title