WO2007089760A2 - Thread forming fasteners for ultrasonic load measurement and control - Google Patents

Thread forming fasteners for ultrasonic load measurement and control Download PDF

Info

Publication number
WO2007089760A2
WO2007089760A2 PCT/US2007/002499 US2007002499W WO2007089760A2 WO 2007089760 A2 WO2007089760 A2 WO 2007089760A2 US 2007002499 W US2007002499 W US 2007002499W WO 2007089760 A2 WO2007089760 A2 WO 2007089760A2
Authority
WO
WIPO (PCT)
Prior art keywords
fastener
load
ultrasonic transducer
ultrasonic
thread
Prior art date
Application number
PCT/US2007/002499
Other languages
French (fr)
Other versions
WO2007089760A3 (en
Inventor
Ian E. Kibblewhite
Robert Molsbergen
Original Assignee
Innovation Plus, Llc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Innovation Plus, Llc filed Critical Innovation Plus, Llc
Publication of WO2007089760A2 publication Critical patent/WO2007089760A2/en
Publication of WO2007089760A3 publication Critical patent/WO2007089760A3/en

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B31/00Screwed connections specially modified in view of tensile load; Break-bolts
    • F16B31/02Screwed connections specially modified in view of tensile load; Break-bolts for indicating the attainment of a particular tensile load or limiting tensile load
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B25/00Screws that cut thread in the body into which they are screwed, e.g. wood screws
    • F16B25/10Screws performing an additional function to thread-forming, e.g. drill screws or self-piercing screws
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16BDEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B31/00Screwed connections specially modified in view of tensile load; Break-bolts
    • F16B31/02Screwed connections specially modified in view of tensile load; Break-bolts for indicating the attainment of a particular tensile load or limiting tensile load
    • F16B2031/022Screwed connections specially modified in view of tensile load; Break-bolts for indicating the attainment of a particular tensile load or limiting tensile load using an ultrasonic transducer
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/42Piezoelectric device making

Definitions

  • This invention relates to load indicating fasteners that are "thread-forming" (also referred to as
  • thread-rolling or “self-tapping” fasteners
  • methods for making load indicating thread-forming fasteners and methods for measuring the load in thread-forming fasteners.
  • Thread-forming fasteners are well known in many industries, such as in high-volume automotive assembly . Examples of such fasteners are described in U.S. Patent No. 5,242,253 (Fulmer) , issued September 1, 1993, for example. Such fasteners are also marketed commercially, for example, by Reminc , Research Engineering and Manufacturing Inc., Middletown, RI, USA, under the trademark "Taptite” and “Taptite 2000", and a description of such fasteners can be found in their product literature, entitled “Taptite 2000 Thread Rolling Fasteners” .
  • thread-forming fasteners The major advantage of thread-forming fasteners is that they can be installed directly into a drilled hole, eliminating the cost of tapping the hole. Additionally, the thread formed by a thread-forming fastener has very tight tolerance since it is formed by the fastener itself and therefore forms a better nut.
  • thread-forming fasteners have been used in numerous applications in the automotive and aerospace industries to reduce cost, such fasteners are generally restricted to non-critical or less-critical applications. The difficulty in controlling the tightening process prevents their use in critical applications .
  • Steps can then be taken, using equipment and methods that are otherwise known and conventional, to accurately measure and control the load in the thread-forming fastener during tightening, and to inspect the load in the thread-forming fastener after assembly.
  • equipment and methods that are otherwise known and conventional, to accurately measure and control the load in the thread-forming fastener during tightening, and to inspect the load in the thread-forming fastener after assembly.
  • Figure 1 shows an example of a typical load indicating thread-forming fastener which is produced in accordance with the present invention.
  • Figures 2 and 3 are graphs showing typical load and torque characteristics plotted against the angle of rotation of the load indicating thread-forming fastener of the present invention.
  • FIG. 1 shows a typical embodiment of a load indicating thread-forming fastener which is produced in accordance with the present invention.
  • the load indicating thread-forming fastener has been implemented in conjunction with an otherwise conventional "Taptite" fastener, which is commercially available from Reminc, Research Engineering and Manufacturing Inc.,
  • load indicating thread-forming fastener of the present invention can also be implemented using any of a variety of known and available load indicating devices, coupled or combined with any of a variety of known and available thread-forming fasteners.
  • the load indicating thread-forming fastener 10 generally includes a fastener 12 (e.g., the above-mentioned "Taptite” fastener) and a permanent piezoelectric polymer film transducer 14 (e.g., of the type disclosed in the above-mentioned U.S. Patent No. 4,846,001, issued to Kibblewhite) attached to one end.
  • the fastener 12 includes a head 16, which can be suitably engaged by a tool (not shown) for applying torque to the fastener 12, and a thread-forming body portion 18.
  • a suitable identifying element is applied to the thread-forming fastener which can be read and used to determine ultrasonic measurement parameters specific to the thread-forming fastener in order to provide more precise and more reliable load measurements by compensating for differences resulting from manufacturing variations in individual thread-forming fasteners.
  • the transducer 14 can further include a permanent mark such as a two-dimensional high-density bar code (not shown) or some other encodable medium, applied to the top electrode 20 of the transducer 14 for purposes of facilitating subsequent steps taken to obtain an indication of tensile load, stress, elongation or other characteristic of the fastener 12 during a tightening operation, or at various other times during the service life of the fastener 12, as will be discussed more fully below.
  • a permanent mark such as a two-dimensional high-density bar code (not shown) or some other encodable medium
  • the permanent mark can be applied directly to the thread-forming fastener, and the ultrasonic transducer can then be applied on top of the mark in such a way that the mark can be detected through the transducer.
  • the bar code can be marked on an end surface of the fastener and the ultrasonic transducer can then be provided on the surface with the bar code in such a manner that the bar code can be read through the transducer.
  • the transducer layers are translucent or transparent, allowing the bar code to be read through the piezoelectric and conductive layers of the transducer.
  • the bar code is marked using an indentation technique, such as dot peening, so that the indentations are detectable, and the bar code is made readable, after application of the transducer.
  • a non-volatile memory device can be applied to the thread-forming fastener for purposes of storing desired information.
  • Such memory devices can be powered, written to and read from serially through a single input/output connection and an AC coupled return through the capacitance of the ultrasonic transducer.
  • Such devices are capable of storing data such as unique identification, ultrasonic measurement parameters, tightening and inspection data for use in a manner similar to that of the above-described use of a permanent mark for the storage of information.
  • the previously described top electrode 20 is replaced with the non-volatile memory device, and portions of the top exposed surface of the memory device are made conductive by providing the surface with an electrical contact .
  • This top conductive surface is then electrically connected to a conductive layer on the bottom of the memory device, adjacent to the active piezoelectric polymer film transducer 14, to provide a suitable electrode for the ultrasonic transducer.
  • the top conductive surface is also electrically connected to the non-volatile memory device for purposes of writing information to and reading information from the memory device.
  • the foregoing non-volatile memory device can be a radio frequency identification (RFID) chip or tag coupled with the transducer 14 for purposes of storing desi ⁇ red information.
  • RFID radio frequency identification
  • the previously described top electrode 20 is replaced with the RFID device, and portions of the top exposed surface of the RFID device are made conductive by providing the exposed surface with an electrical contact .
  • This top conductive surface is then electrically connected to a conductive layer on the bottom of the RFID device, adjacent to the active, piezoelectric polymer film transducer 14, to provide a suitable electrode for the transducer 14.
  • the piezoelectric polymer film transducer 14 is an electrical insulator and further functions as an isolator for the antenna associated with the RFID device for purposes of RF transmission.
  • the size, shape and location of the conductive portions of the top exposed surface of the RFID device can vary to suit the particular RFID device which is used.
  • the conductive portions of the top exposed surface can be placed along the periphery of the RFID device, leaving the central portions of the top exposed surface open to accommodate the antenna normally associated with the RFID device.
  • the conductive portions of the top exposed surface should preferably cover as much of the top surface of the RFID device as is possible, while leaving sufficient open space to accommodate the function of the antenna.
  • the conductive layer on the bottom of the RFID device preferably covers the entire bottom surface, to maximize contact with the transducer 14.
  • RFID devices including electromagnetic, capacitive and inductive couplings , with different coupling antennas .
  • the antenna can be provided adjacent to non-conductive portions of the top exposed surface.
  • the conductive portions of the top and bottom surfaces of the RFID device can be constructed in such a way as to function as the antenna for the transponder associated with the RFID device which is used.
  • non-contact inductive or capacitive couplings used for RFID transponder communication in the above described embodiments can also be used to couple the excitation signal to the ultrasonic transducer.
  • the RF communication frequency can be selected to correspond to a preferred ultrasonic transducer excitation frequency; This then eliminates the need for an electrically conductive top surface for electrical contact with the transducer for load measurement, allowing both the reading of information stored in the RFID device and the measurement of load to be performed even when the transducer is covered with paint or other protective coating.
  • the transducer 14 can be implemented using a thin piezoelectric polymer sensor (e.g., a 9 micron thick, polyvinylidene fluoride copolymer film, of the type manufactured by Measurement Specialties Inc., Valley Forge, PA, USA) permanently, mechanically and acoustically attached to an end surface 22 of the fastener 12.
  • the top electrode 20 of the transducer 14 can be implemented as a thin metallic foil (e.g., an approximately 50 micron thick, type 316, full-hard, dull or matte finished stainless steel) which has been treated to provide a black oxide finish, which is then preferably provided with a black oxide treatment to provide an extremely thin, durable, corrosion resistant and electrically conductive, black coating.
  • a high-resolution bar code can be marked on the resulting surface by removing selected areas of the coating (e.g., by conventional laser ablation techniques) , or by some other process, to provide a high contrast mark easily read with conventional, commercially available optical readers.
  • a non-volatile memory device such as an RFID device, can be applied to the transducer 14 to provide data storage which can similarly be read with conventional, commercially available readers.
  • the ultrasonic transducer 14 can be implemented as an oriented piezoelectric thin film, vapor deposited directly on the head of the fastener 12, as is described in U.S. Patent No. 5,131,276 (Kibblewhite) , issued July 21, 1992.
  • the ultrasonic transducer 14 can be implemented as a piezoelectric polymer film, chemically grafted on the head of the fastener 12, as is described in U.S. Provisional Patent Application No. 60/264,877 (Kibblewhite), filed January
  • the ultrasonic transducer 14 is permanently attached to the head 16 of the fastener 12, as described in the above-referenced patents issued to Kibblewhite.
  • An essentially flat, or spherically radiused surface 24 is provided on at least a portion of the threaded end of the fastener to provide an acoustically reflective surface to reflect the ultrasonic wave transmitted by the transducer back to the transducer.
  • Load is then measured using standard, pulse-echo ultrasonic techniques, which are themselves known in the art and described, for example, in the above-referenced patents issued to Kibblewhite. Load control accuracies of ⁇ 3% have been achieved when tightening thread-forming fasteners into blind holes during both the first and subsequent tightenings .
  • an essentially flat surface is provided on the head 16 of the thread-forming fastener 12 and a removable ultrasonic transducer is temporarily attached to the fastener for the purpose of making load measurements .
  • the threaded end of the fastener 12 is identical to the previous embodiment with the permanent ultrasonic transducer.
  • FIGS. 2 and 3 show typical load and torque characteristics plotted against the angle of rotation of a typical bolt.
  • Figure 2 shows the tightening curves for a typical through-hole application, in which the torque reduces after the thread is formed through the entire hole.
  • Figure 3 shows the tightening curves for a typical blind hole application, in which the thread is still being formed as the bolt is tightened.
  • the load-inducing stage of the assembly process can be detected by any one of a variety of methods .
  • an increase in load above a predetermined threshold, a change in the increase in load with time, angle of rotation of the fastener or torque, an increase in torque above a predetermined threshold, or a change in the increase in torque with time, angle or load can be detected- Irrespective of the method used to detect the load-inducing stage of the assembly process, a new zero-load base measurement is taken as a value just prior to the load-inducing assembly stage by selecting or calculating a load measurement prior to the load-inducing stage.
  • the thermal effect of thread forming causes an apparent positive load value at zero load just prior to tightening-
  • An alternative to zeroing the load (or time-of-flight measurement) is to add this load offset, measured prior to the load-inducing stage of the assembly process, to the target load (or target time-of-flight) .
  • the result is the same since the increase in measured load is the same .
  • Yet another alternative is to experimentally determine an average value of load error due to the thread forming and adjust the zero-load measurement or target tightening parameter to compensate for this effect using one of the above-described methods. This approach, however, does not compensate for variations with individual fasteners or joint components and is therefore presently considered less desirable .
  • Thread-locking bolts and nuts are manufactured with a prevailing "locking" torque to prevent the fastener from loosening during service.
  • the thread of either the bolt or nut has an irregular profile causing the threads to elastically deform slightly upon mating.
  • the bolt or nut has an insert or patch of a soft material to provide the prevailing torque or resistance to loosening.
  • the prevailing torque provided by these thread-locking features produces heating of the fastener during rundown in the same manner as the tapping torque does with a thread-forming fastener. Consequently, the above-described method for compensating for thermal-related errors in accordance with the present invention can be used with prevailing torque-locking fasteners to improve the accuracy of ultrasonic load measurement during assembly.

Abstract

An ultrasonic load measurement transducer (14) is mated with a thread-forming fastener (12) to provide a load indicating thread-forming fastener that can be used for the precise and reliable assembly of critical bolted joints, such as those in the automobile and aerospace industries, among others. Steps can then be taken to accurately measure and control the load in the thread-forming fastener during tightening, and to inspect the load in the thread-forming fastener after assembly. A similar result can be achieved for a thread-locking fastener by mating an ultrasonic transducer with the thread-locking fastener assembly.

Description

THREAD FORMING FASTENERS FOR ULTRASONIC LOAD MEASUREMENT AND CONTRQI,
Background of the Invention
This invention relates to load indicating fasteners that are "thread-forming" (also referred to as
"thread-rolling" or "self-tapping" fasteners) , methods for making load indicating thread-forming fasteners, and methods for measuring the load in thread-forming fasteners.
Thread-forming fasteners are well known in many industries, such as in high-volume automotive assembly . Examples of such fasteners are described in U.S. Patent No. 5,242,253 (Fulmer) , issued September 1, 1993, for example. Such fasteners are also marketed commercially, for example, by Reminc , Research Engineering and Manufacturing Inc., Middletown, RI, USA, under the trademark "Taptite" and "Taptite 2000", and a description of such fasteners can be found in their product literature, entitled "Taptite 2000 Thread Rolling Fasteners" .
The major advantage of thread-forming fasteners is that they can be installed directly into a drilled hole, eliminating the cost of tapping the hole. Additionally, the thread formed by a thread-forming fastener has very tight tolerance since it is formed by the fastener itself and therefore forms a better nut.
Although thread-forming fasteners have been used in numerous applications in the automotive and aerospace industries to reduce cost, such fasteners are generally restricted to non-critical or less-critical applications. The difficulty in controlling the tightening process prevents their use in critical applications .
The primary reason for this is that the thread-forming process requires torque, in addition to the tightening torque, and this thread-forming torque varies significantly with hole tolerance, material, friction conditions, etc. As a result, the precise tightening of a thread-forming fastener to a specified torque into a blind hole, where the thread is still being formed as the bolt is being tightened, will result in a 3 sigma load scatter of typically ±50%, which is unacceptable in critical applications .
Summary of the Invention
For some time, ultrasonics has been used to accurately measure the load in bolts. Initially, removable ultrasonic devices were the most commonly used. More recently, low-cost permanent ultrasonic transducers, which can be permanently attached to one end of the fastener, have come to be used. Permanent fasteners of this type are described, for example, in U.S. Patent No. 4,846,001 (Kibblewhite) , issued July 11 , 1989, U.S. Patent No. 5,131,276
(Kibblewhite) , issued July 21, 1992, U.S. Provisional Patent
Application No. 60/264,877 (Kibblewhite), filed January 29,
2001, and International Application No. PCT/US02/03920
(Kibblewhite), filed May 17, 2002, the subject matter of which is incorporated by reference herein.
In accordance with the present invention, it has been determined that such ultrasonics can be mated with an otherwise conventional thread-forming fastener to provide a load indicating thread-forming fastener that can be used for precise and reliable assembly of critical bolted joints, such as those in automobile engines (e.g., cylinder heads, connecting rods, main bearings, etc.) , drive trains, steering,
•brakes, suspensions, and a variety of other applications, including aerospace applications . Steps can then be taken, using equipment and methods that are otherwise known and conventional, to accurately measure and control the load in the thread-forming fastener during tightening, and to inspect the load in the thread-forming fastener after assembly. For further detail regarding preferred embodiments for implementing the improvements of the present invention, reference is made to the description which is provided below, together with the following illustrations.
Brief Description of the Drawings
Figure 1 shows an example of a typical load indicating thread-forming fastener which is produced in accordance with the present invention.
Figures 2 and 3 are graphs showing typical load and torque characteristics plotted against the angle of rotation of the load indicating thread-forming fastener of the present invention.
Detailed Description of the Invention
Figure 1 shows a typical embodiment of a load indicating thread-forming fastener which is produced in accordance with the present invention. In this illustrative example, the load indicating thread-forming fastener has been implemented in conjunction with an otherwise conventional "Taptite" fastener, which is commercially available from Reminc, Research Engineering and Manufacturing Inc.,
Middletown, RI, USA. It is to be understood, however, that this embodiment is shown only for purposes of illustration, and that the load indicating thread-forming fastener of the present invention can also be implemented using any of a variety of known and available load indicating devices, coupled or combined with any of a variety of known and available thread-forming fasteners.
In the illustrative embodiment of Figure 1 , the load indicating thread-forming fastener 10 generally includes a fastener 12 (e.g., the above-mentioned "Taptite" fastener) and a permanent piezoelectric polymer film transducer 14 (e.g., of the type disclosed in the above-mentioned U.S. Patent No. 4,846,001, issued to Kibblewhite) attached to one end. The fastener 12 includes a head 16, which can be suitably engaged by a tool (not shown) for applying torque to the fastener 12, and a thread-forming body portion 18. A suitable identifying element is applied to the thread-forming fastener which can be read and used to determine ultrasonic measurement parameters specific to the thread-forming fastener in order to provide more precise and more reliable load measurements by compensating for differences resulting from manufacturing variations in individual thread-forming fasteners.
For example, as disclosed in U.S. Provisional Patent Application No. 60/264,877 (Kibblewhite) and International Application No. PCT/US02/03920 (Kibblewhite) , the transducer 14 can further include a permanent mark such as a two-dimensional high-density bar code (not shown) or some other encodable medium, applied to the top electrode 20 of the transducer 14 for purposes of facilitating subsequent steps taken to obtain an indication of tensile load, stress, elongation or other characteristic of the fastener 12 during a tightening operation, or at various other times during the service life of the fastener 12, as will be discussed more fully below.
As an alternative, the permanent mark can be applied directly to the thread-forming fastener, and the ultrasonic transducer can then be applied on top of the mark in such a way that the mark can be detected through the transducer. As an example, the bar code can be marked on an end surface of the fastener and the ultrasonic transducer can then be provided on the surface with the bar code in such a manner that the bar code can be read through the transducer. In one such embodiment, the transducer layers are translucent or transparent, allowing the bar code to be read through the piezoelectric and conductive layers of the transducer. In another embodiment, the bar code is marked using an indentation technique, such as dot peening, so that the indentations are detectable, and the bar code is made readable, after application of the transducer.
As a further alternative, a non-volatile memory device can be applied to the thread-forming fastener for purposes of storing desired information. Such memory devices can be powered, written to and read from serially through a single input/output connection and an AC coupled return through the capacitance of the ultrasonic transducer. Such devices are capable of storing data such as unique identification, ultrasonic measurement parameters, tightening and inspection data for use in a manner similar to that of the above-described use of a permanent mark for the storage of information.
In one such embodiment, the previously described top electrode 20 is replaced with the non-volatile memory device, and portions of the top exposed surface of the memory device are made conductive by providing the surface with an electrical contact . This top conductive surface is then electrically connected to a conductive layer on the bottom of the memory device, adjacent to the active piezoelectric polymer film transducer 14, to provide a suitable electrode for the ultrasonic transducer. The top conductive surface is also electrically connected to the non-volatile memory device for purposes of writing information to and reading information from the memory device.
In another embodiment, the foregoing non-volatile memory device can be a radio frequency identification (RFID) chip or tag coupled with the transducer 14 for purposes of storing desi÷red information. This can be accomplished with known RFID devices, such as the MetalSentinel (13.56MHz) device available from Interactive Mobile Systems, Inc., Port Townsend, WA, USA, which are capable of storing data such as unique identification, ultrasonic measurement parameters, and tightening and inspection data. In such an embodiment, the previously described top electrode 20 is replaced with the RFID device, and portions of the top exposed surface of the RFID device are made conductive by providing the exposed surface with an electrical contact . This top conductive surface is then electrically connected to a conductive layer on the bottom of the RFID device, adjacent to the active, piezoelectric polymer film transducer 14, to provide a suitable electrode for the transducer 14. The piezoelectric polymer film transducer 14 is an electrical insulator and further functions as an isolator for the antenna associated with the RFID device for purposes of RF transmission.
The size, shape and location of the conductive portions of the top exposed surface of the RFID device can vary to suit the particular RFID device which is used. For example, the conductive portions of the top exposed surface can be placed along the periphery of the RFID device, leaving the central portions of the top exposed surface open to accommodate the antenna normally associated with the RFID device. The conductive portions of the top exposed surface should preferably cover as much of the top surface of the RFID device as is possible, while leaving sufficient open space to accommodate the function of the antenna. The conductive layer on the bottom of the RFID device preferably covers the entire bottom surface, to maximize contact with the transducer 14.
Various different couplings are used with RFID devices, including electromagnetic, capacitive and inductive couplings , with different coupling antennas . The antenna can be provided adjacent to non-conductive portions of the top exposed surface. Alternatively, the conductive portions of the top and bottom surfaces of the RFID device can be constructed in such a way as to function as the antenna for the transponder associated with the RFID device which is used. It will further be appreciated that non-contact inductive or capacitive couplings used for RFID transponder communication in the above described embodiments can also be used to couple the excitation signal to the ultrasonic transducer. Additionally, the RF communication frequency can be selected to correspond to a preferred ultrasonic transducer excitation frequency; This then eliminates the need for an electrically conductive top surface for electrical contact with the transducer for load measurement, allowing both the reading of information stored in the RFID device and the measurement of load to be performed even when the transducer is covered with paint or other protective coating.
As an example, the transducer 14 can be implemented using a thin piezoelectric polymer sensor (e.g., a 9 micron thick, polyvinylidene fluoride copolymer film, of the type manufactured by Measurement Specialties Inc., Valley Forge, PA, USA) permanently, mechanically and acoustically attached to an end surface 22 of the fastener 12. The top electrode 20 of the transducer 14 can be implemented as a thin metallic foil (e.g., an approximately 50 micron thick, type 316, full-hard, dull or matte finished stainless steel) which has been treated to provide a black oxide finish, which is then preferably provided with a black oxide treatment to provide an extremely thin, durable, corrosion resistant and electrically conductive, black coating. A high-resolution bar code can be marked on the resulting surface by removing selected areas of the coating (e.g., by conventional laser ablation techniques) , or by some other process, to provide a high contrast mark easily read with conventional, commercially available optical readers. As an alternative, a non-volatile memory device, such as an RFID device, can be applied to the transducer 14 to provide data storage which can similarly be read with conventional, commercially available readers.
It is again to be understood that such implementations are described only for. purposes of illustration, and that any of a variety of transducer configurations can be used to implement the transducer 14 applied to the fastener 12, as desired. For example, the ultrasonic transducer 14 can be implemented as an oriented piezoelectric thin film, vapor deposited directly on the head of the fastener 12, as is described in U.S. Patent No. 5,131,276 (Kibblewhite) , issued July 21, 1992. As a further alternative, the ultrasonic transducer 14 can be implemented as a piezoelectric polymer film, chemically grafted on the head of the fastener 12, as is described in U.S. Provisional Patent Application No. 60/264,877 (Kibblewhite), filed January
29, 2001, and International Application No. PCT/US02/03920
(Kibblewhite), filed May 17, 2002. It will be readily understood that other alternative implementations are also possible. In the embodiment illustrated in Figure 1 , the ultrasonic transducer 14 is permanently attached to the head 16 of the fastener 12, as described in the above-referenced patents issued to Kibblewhite. An essentially flat, or spherically radiused surface 24 is provided on at least a portion of the threaded end of the fastener to provide an acoustically reflective surface to reflect the ultrasonic wave transmitted by the transducer back to the transducer. Load is then measured using standard, pulse-echo ultrasonic techniques, which are themselves known in the art and described, for example, in the above-referenced patents issued to Kibblewhite. Load control accuracies of ±3% have been achieved when tightening thread-forming fasteners into blind holes during both the first and subsequent tightenings .
In an alternative embodiment, an essentially flat surface is provided on the head 16 of the thread-forming fastener 12 and a removable ultrasonic transducer is temporarily attached to the fastener for the purpose of making load measurements . The threaded end of the fastener 12 is identical to the previous embodiment with the permanent ultrasonic transducer.
In practice, heat is generated as a result of the thread-forming work that takes place during the thread-forming run-down stage of the installation of a thread-forming fastener. This results in a slight increase in temperature in both the fastener (the bolt) and the resulting joint. This increase in temperature can cause errors in the ultrasonic load measurements to be taken because of thermal expansion effects. For this reason, when using ultrasonics for inspecting the load in a fastener, it is usual to measure the temperature of the fastener or the joint in order to compensate for the effects of thermal expansion.
However, in conjunction with a thread-forming fastener, the average temperature increase due to the heat generated during thread-formation can not be measured directly during the installation process and is subject to variations in material, friction, and heat conduction properties of the joint components. Without compensation, this thermal effect can result in inaccuracies of load measurement on the order of 5% to 20%, depending on the bolt, the joint and the assembly process being used. Figures 2 and 3 show typical load and torque characteristics plotted against the angle of rotation of a typical bolt. Figure 2 shows the tightening curves for a typical through-hole application, in which the torque reduces after the thread is formed through the entire hole. Figure 3 shows the tightening curves for a typical blind hole application, in which the thread is still being formed as the bolt is tightened.
Further in accordance with the present invention, more accurate load measurements in the thread-forming load indicating fasteners are provided by eliminating the effects of fastener heating resulting from the thread-forming
•process. This is achieved by measuring the load (or acoustic time-of-flight ) value immediately prior to the load-inducing stage of the assembly process, and by using this measured value as the zero-load reading.
The load-inducing stage of the assembly process can be detected by any one of a variety of methods . For example, an increase in load above a predetermined threshold, a change in the increase in load with time, angle of rotation of the fastener or torque, an increase in torque above a predetermined threshold, or a change in the increase in torque with time, angle or load can be detected- Irrespective of the method used to detect the load-inducing stage of the assembly process, a new zero-load base measurement is taken as a value just prior to the load-inducing assembly stage by selecting or calculating a load measurement prior to the load-inducing stage. This can be achieved by selecting a load measurement corresponding to a fixed time or angle prior to the detection of the commencement of the load-inducing stage, for example. Alternatively, for through-hole applications, the end of the thread-forming phase can be detected by a reduction in torque. It is again to be understood that such methods are only illustrative, and that there are numerous other methods for determining the new zero-load base measurement prior to tightening, from load, time, torque and angle of rotation measurements recorded during assembly operations with hand and powered assembly tools.
The thermal effect of thread forming causes an apparent positive load value at zero load just prior to tightening- An alternative to zeroing the load (or time-of-flight measurement) is to add this load offset, measured prior to the load-inducing stage of the assembly process, to the target load (or target time-of-flight) . The result is the same since the increase in measured load is the same . Yet another alternative is to experimentally determine an average value of load error due to the thread forming and adjust the zero-load measurement or target tightening parameter to compensate for this effect using one of the above-described methods. This approach, however, does not compensate for variations with individual fasteners or joint components and is therefore presently considered less desirable .
The result is that, for the first time, ultrasonic load measurement technology can be used with thread-forming fasteners. Errors in load measurement resulting from the thermal effects of thread-forming can be compensated. This then results in accurate load measurement and tightening control of the thread-forming fasteners.
The above-described method of eliminating the effects of fastener heating resulting from the thread-forming process can also be used with other fastener assembly processes that generate heat prior to the load-inducing tightening stage. Thread-locking bolts and nuts, for example, are manufactured with a prevailing "locking" torque to prevent the fastener from loosening during service. Most often, the thread of either the bolt or nut has an irregular profile causing the threads to elastically deform slightly upon mating. Alternatively, the bolt or nut has an insert or patch of a soft material to provide the prevailing torque or resistance to loosening. The prevailing torque provided by these thread-locking features produces heating of the fastener during rundown in the same manner as the tapping torque does with a thread-forming fastener. Consequently, the above-described method for compensating for thermal-related errors in accordance with the present invention can be used with prevailing torque-locking fasteners to improve the accuracy of ultrasonic load measurement during assembly.
It will be understood that various changes in the details, materials and arrangement of parts which have been herein described and illustrated in order to explain the nature of this invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the following claims.

Claims

ClaimsWhat is claimed is:
1. An apparatus comprising: a thread-forming fastener including a head for engagement by a tool for applying a torque to the fastener, and a body portion extending from the head and including thread-forming portions; and an ultrasonic transducer coupled with the fastener, for making ultrasonic load measurements in the fastener.
2. The apparatus of claim 1 wherein the ultrasonic transducer is coupled with the head of the fastener.
3. The apparatus of claim 1 wherein the ultrasonic transducer is permanently attached to the fastener.
4. The apparatus of claim 3 wherein the ultrasonic transducer is comprised of a piezoelectric polymer film permanently attached to the head of the fastener.
5. The apparatus of claim 3 wherein the ultrasonic transducer is comprised of an oriented piezoelectric thin film, vapor deposited directly on the head of the fastener.
6. The apparatus of claim 1 wherein the ultrasonic transducer is temporarily attached to the fastener.
7. The apparatus of claim 1 which further includes an identifying element applied to the apparatus, wherein the identifying element includes data associated with the fastener.
8. The apparatus of claim 7 wherein the identifying element is a permanent mark applied to the apparatus.
9. The apparatus of claim 8 wherein the permanent mark is a bar code.
10. The apparatus of claim 9 wherein the bar code is applied to the ultrasonic transducer .
11. The apparatus of claim 9 wherein the bar code is applied to the fastener, and the ultrasonic transducer is applied over the bar code.
12. The apparatus of claim 11 wherein the ultrasonic transducer is formed of a translucent material.
13. The apparatus of claim 8 wherein the permanent mark is an indentation formed in a surface of the fastener.
14. The apparatus of claim 8 wherein the permanent mark is applied to an end surface of the fastener.
15. The apparatus of claim 7 wherein the identifying element is a non-volatile memory device applied to the ultrasonic transducer.
16 - The apparatus of claim 15 wherein the non-volatile memory device has a top surface and a bottom surface, and an exposed conductive layer on portions of the top surface which is electrically connected to a conductive layer on the bottom surface, and wherein the conductive layer on the bottom surface is in close proximity to an active element of the ultrasonic transducer so that the bottom conductive layer functions as an electrode.
17. The apparatus of claim 16 wherein the conductive layer on the top surface is electrically connected to the non-volatile memory device, for writing information to and for reading information from the memory device.
18. The apparatus of claim 15 wherein the non-volatile memory device is a radio frequency identification device.
19- The apparatus of claim 18 wherein the portions of the conductive layer on the top surface and the conductive layer on the bottom surface function as an antenna for communicating with a transponder associated with the radio frequency identification device.
20. The apparatus of claim 18 wherein the radio frequency identification device has an antenna, and wherein the antenna provides a non-contact coupling with the ultrasonic transducer for performing ultrasonic load measurements -
21. The apparatus of claim 18 wherein the ultrasonic transducer and the radio frequency identification device each operate at a defined frequency, and wherein the frequency for the ultrasonic transducer is the same as the frequency for the radio frequency identification device.
22. A method of making a load indicating, thread-forming fastener, comprising the steps of: providing a fastener having a first end including a surface for receiving an ultrasonic transducer, for making ultrasonic load measurements in the fastener, a shank extending from the first end and including thread-forming portions for tapping a hole, and a second end, opposite the first end and including a surface for reflecting an ultrasonic wave back to the first end; and attaching an ultrasonic transducer to the first end of the fastener.
23. The method of claim 22 which further includes the step of attaching the ultrasonic transducer to a head associated with the first end of the thread-forming fastener, for engagement by a tool for applying a torque to the fastener.
24. The method of claim 22 which, further includes the step of permanently attaching the ultrasonic transducer to the fastener.
25. The method of claim 24 which further includes the step of permanently attaching an ultrasonic transducer comprised of a piezoelectric polymer film to the first end of the fastener.
26. The method of claim 24 which further includes the step of vapor depositing an ultrasonic transducer comprised of an oriented piezoelectric thin film directly onto the first end of the fastener.
27. The method of claim 22 which further includes the step of temporarily attaching the ultrasonic transducer to the fastener.
28. The method of claim 22 which further includes the step of applying an identifying element to the fastener, wherein the identifying element includes data associated with the fastener.
29. The method of claim 28 which further includes the step of applying a permanent mark to the fastener.
30. The method of claim 29 which further includes the step of applying a bar code to the fastener.
31. The method of claim 30 which further includes the step of applying the bar code to the ultrasonic transducer .
32. The method of claim 30 which further includes the steps of applying the bar code directly to the fastener, and applying the ultrasonic transducer over the bar code.
33. The method of claim 28 which further includes the step of forming an indentation in a surface of the fastener.
34. The method of claim 28 which further includes the step of applying the identifying element to an end surface of the fastener.
35. The method of claim 28 which further includes the step of applying a non-volatile memory device to the ultrasonic transducer.
36. The method of claim 35 which further includes the steps of providing an exposed conductive layer on portions of a top surface of the non-volatile memory device, and electrically connecting the exposed conductive layer to a conductive layer on a bottom surface of the non-volatile memory device, placing the conductive layer on the bottom surface in close proximity to an active element of the ultrasonic transducer so that the bottom conductive layer functions as an electrode.
37. The method of claim 36 which further includes the step of electrically connecting the conductive layer on the top surface to the non-volatile memory device, for communicating with the memory device.
38. The method of claim 35 which further includes the step of applying a radio frequency identification device to the ultrasonic transducer.
39. A method of measuring a load in a fastener, comprising the steps of: providing a thread-forming fastener including a head for engagement by a tool for applying a torque to the fastener, and a body portion extending from the head and including thread-forming portions ; coupling an ultrasonic transducer with the fastener, for making ultrasonic load measurements in the fastener; electrically connecting an apparatus to the ultrasonic transducer for supplying signals to the ultrasonic transducer and for receiving signals from the ultrasonic transducer; monitoring the signals received from the ultrasonic transducer, providing an accurate measurement indicative of the load m the fastener; and adjusting the measurement indicative of the load to compensate for effects of heating of the fastener resulting from forming a thread in. a mating component during installation.
40. The method of claim 39 which further includes the step of imparting torque to the fastener and removing torque from the fastener in response to the measurement of the load m the fastener.
41. The method of claim 39 which further includes the step of determining a zero-load ultrasonic measurement, using the measurement indicative of the load m the fastener.
42. The method of claim 41 which further includes the step of measuring a torque in conjunction with the measurement indicative of the load in the fastener to determine the zero-load ultrasonic measurement.
43. The method of claim 41 which further includes the step of measuring an angle of rotation of the fastener in conjunction with the measurement indicative of the load in the fastener to determine the zero-load ultrasonic measurement.
44. The method of claim 41 which further includes the step of measuring time in conjunction with the measurement indicative of the load in the fastener to determine the zero-load ultrasonic measurement.
45. The method of claim 41 which further includes the step of taking measurements for determining the zero-load ultrasonic measurement prior to a load-inducing stage of the installation.
46. The method of claim 41 which further includes the step of taking measurements for determining the zero-load ultrasonic measurement during a load-inducing stage of the installation.
47. The method of claim 39 which further includes the step of placing an identifying element on the fastener which contains data associated with the fastener.
48. The method of claim 47 wherein the identifying element is a permanent mark applied to the ultrasonic transducer, and wherein the method further includes the step of directly reading the permanent mark applied to the ultrasonic transducer.
49. The method of claim 47 wherein the identifying element is a permanent mark applied to the fastener, wherein the ultrasonic transducer is applied over the permanent mark, and wherein the method further includes the step of reading the permanent mark applied to the fastener through the ultrasonic transducer.
50. The method of claim 47 wherein the identifying element is a non-volatile memory device applied to the ultrasonic transducer, and wherein the method further includes the step of directly reading the non-volatile memory device applied to the ultrasonic transducer.
51. A method of measuring a load in a fastener, comprising the steps of: providing a thread-locking fastener assembly including a bolt having a head for engagement by a tool for applying a torque to the fastener assembly and a body portion extending from the head, and a nut for cooperating with the body portion of the bolt, wherein portions of the fastener assembly include resistance-inducing threads; coupling an ultrasonic transducer with the bolt, for making ultrasonic load measurements in the fastener assembly; electrically connecting an apparatus to the ultrasonic transducer for supplying signals to the ultrasonic transducer and for receiving signals from the ultrasonic transducer; monitoring the signals received from the ultrasonic transducer, providing an accurate measurement indicative of the load in the fastener assembly; and adjusting the measurement indicative of the load to compensate for effects of heating of the fastener assembly resulting from prevailing torque associated with the thread-locking fastener assembly.
52. The method of claim 51 which further includes the step of imparting torque to the bolt and removing torque from the bolt in response to the measurement of the load in the fastener assembly.
53. The method of claim 51 which further includes the step of determining a zero-load ultrasonic measurement, using the measurement indicative of the load in the fastener assembly .
54. The method of claim 53 which further includes the step of measuring a torque m conjunction with the measurement indicative of the load m the fastener assembly to determine the zero-load ultrasonic measurement .
55. The method of claim 53 which further includes the step of measuring an angle of rotation of the fastener m conjunction with the measurement indicative of the load m the fastener assembly to determine the zero-load ultrasonic measurement .
56. The method of claim 53 which further includes the step of measuring time m conjunction with the measurement indicative of the load m the fastener assembly to determine the zero-load ultrasonic measurement.
57. The method of claim 53 which further includes the step of taking measurements for determining the zero-load ultrasonic measurement prior to inducing the load m the fastener assembly.
58. The method of claim 53 which further includes the step of taking measurements for determining the zero-load ultrasonic measurement while inducing the load m the fastener assembly.
59. The method of claim 51 which further includes the step of placing an identifying element on the fastener assembly which contains data associated with the fastener assembly.
60. The method of claim 59 wherein the identifying element is a permanent mark applied to the ultrasonic transducer, and wherein the method further includes the step of directly reading the permanent mark applied to the ultrasonic transducer.
61. The method of claim 59 wherein the identifying element is a permanent mark applied to the fastener assembly, wherein the ultrasonic transducer is applied over the permanent mark, and wherein the method further includes the step of reading the permanent mark applied to the fastener assembly through the ultrasonic transducer.
62. The method of claim 59 wherein the identifying element is a non-volatile memory device applied to the ultrasonic transducer, and wherein the method further includes the step of directly reading 'the non-volatile memory device applied to the ultrasonic transducer.
PCT/US2007/002499 2006-01-31 2007-01-29 Thread forming fasteners for ultrasonic load measurement and control WO2007089760A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/344,028 2006-01-31
US11/344,028 US7467556B2 (en) 2001-01-29 2006-01-31 Thread forming fasteners for ultrasonic load measurement and control

Publications (2)

Publication Number Publication Date
WO2007089760A2 true WO2007089760A2 (en) 2007-08-09
WO2007089760A3 WO2007089760A3 (en) 2008-09-25

Family

ID=38327994

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/002499 WO2007089760A2 (en) 2006-01-31 2007-01-29 Thread forming fasteners for ultrasonic load measurement and control

Country Status (2)

Country Link
US (3) US7467556B2 (en)
WO (1) WO2007089760A2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7650792B2 (en) 2001-01-29 2010-01-26 Innovation Plus, Llc Load indicating member with identifying element
US7946179B2 (en) 2001-01-29 2011-05-24 Innovation Plus, Llc Thread forming fasteners for ultrasonic load measurement and control
US8033181B2 (en) 2001-01-29 2011-10-11 Innovation Plus, Llc Probe for fastener identification and ultrasonic load measurement

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1549862B1 (en) * 2002-09-19 2008-01-23 Innovation Plus, L.L.C. Thread forming fasteners for ultrasonic load measurement and control
US7698949B2 (en) * 2005-09-09 2010-04-20 The Boeing Company Active washers for monitoring bolted joints
EP2008342B1 (en) * 2006-04-06 2015-01-28 Innovation Plus, L.L.C. System for dynamically controlling the torque output of a pneumatic tool
US20080178713A1 (en) * 2007-01-31 2008-07-31 Robert Earl Long Fastener tightening system utilizing identification technology
US8391561B2 (en) * 2007-07-03 2013-03-05 G-coder Systems AB Pre tension monitoring solution
US8810370B2 (en) 2010-01-22 2014-08-19 The Boeing Company Wireless collection of fastener data
US8978967B2 (en) * 2007-10-31 2015-03-17 The Boeing Campany Intelligent fastener system
US8683869B2 (en) * 2008-09-04 2014-04-01 The Boeing Company Monitoring fastener preload
US8521448B1 (en) 2009-10-21 2013-08-27 The Boeing Company Structural analysis using measurement of fastener parameters
US20100161246A1 (en) * 2008-12-19 2010-06-24 Caterpillar Inc. Fault detection system and method
KR100939847B1 (en) 2009-05-13 2010-01-29 레미코리아 유한회사 Manufacturing method of battery terminal for startmotor
US8578778B2 (en) * 2009-10-15 2013-11-12 The Boeing Company Ultrasonic method to verify the interference fit of fasteners
DE102009060441B4 (en) * 2009-12-22 2014-11-20 Amg Intellifast Gmbh sensor element
US9339926B2 (en) 2010-05-03 2016-05-17 Innovation Plus, Llc System for performing predefined fastener installation procedures
EP2490017A1 (en) * 2011-02-18 2012-08-22 AMG Intellifast GmbH Ultrasound measurement system
US8893557B2 (en) * 2013-01-09 2014-11-25 King Fahd University Of Petroleum And Minerals Fastener tension monitoring system
WO2014198680A1 (en) * 2013-06-12 2014-12-18 Atlas Copco Industrial Technique Ab A method of measuring elongation of a fastener with ultrasound, performed by a power tool, and a power tool
US9483674B1 (en) 2014-03-07 2016-11-01 United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration RFID torque sensing tag system for fasteners
KR101685890B1 (en) * 2015-01-20 2016-12-28 현대자동차주식회사 Apparatus of acoustic wave sensor
EP3210725B1 (en) * 2016-02-23 2019-02-06 TE Connectivity Germany GmbH Hand-operated tool, ground contact mounting set and method for mounting a terminal onto a ground stud contact, in particular for a car body
US20180241139A1 (en) * 2017-02-23 2018-08-23 Lear Corporation Electrical terminal assembly and method of assembling the same
NO344894B1 (en) * 2018-09-12 2020-06-15 Sintef Tto As Assembly and method for measuring strain in a washer
US11022507B2 (en) * 2019-04-05 2021-06-01 Masoud Nasrollahzadeh Ultrasonic sensor
US10938447B1 (en) * 2019-08-08 2021-03-02 The Boeing Company Radio-frequency-identification-based smart fastener

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5165831A (en) * 1989-10-06 1992-11-24 Cummins Engine Company Capscrew head markings for torque-angle tightening
US5970798A (en) * 1997-09-25 1999-10-26 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Ultrasonic bolt gage
US6186010B1 (en) * 1997-12-17 2001-02-13 Toyota Jidosha Kabushiki Kaisha Bolt for ultrasonic axial tension measurement

Family Cites Families (90)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US659890A (en) * 1900-06-18 1900-10-16 Otto O Stillman Eyeglass-hook.
US1909476A (en) * 1931-11-28 1933-05-16 Shakeproof Lock Washer Co Self-tapping screw
US2413797A (en) * 1945-04-16 1947-01-07 Gerotor May Corp Fastening device
US3181672A (en) 1961-06-20 1965-05-04 Gardner Denver Co Tension control wrench
US3774479A (en) 1970-06-08 1973-11-27 Chicago Pneumatic Tool Co Pneumatic marking device
US4281538A (en) 1973-05-14 1981-08-04 Thor Power Tool Company Transducer for indicating torque
US4043222A (en) 1973-05-14 1977-08-23 Thor Power Tool Company Housing construction for a power tool
US4006784A (en) 1973-05-14 1977-02-08 Thor Power Tool Company Fluid operated power tool
US3969810A (en) 1974-05-13 1976-07-20 Pagano Dominick A Method for tightening a bolt to exert a predetermined tension force by monitoring bolt elongation while the bolt is being installed
US3969960A (en) * 1974-05-13 1976-07-20 Dominick A Pagano Method and apparatus for tightening a bolt to exert a predetermined tension force by monitoring bolt elongation while the bolt is being installed
US4008772A (en) 1975-05-19 1977-02-22 Standard Pressed Steel Co. Tightening system
US4074772A (en) 1976-03-04 1978-02-21 Thor Power Tool Company Torquing tool control circuit
US4104778A (en) 1977-01-27 1978-08-08 Ingersoll-Rand Company Method and apparatus for fastener tensioning
US4316512A (en) 1979-04-04 1982-02-23 Sps Technologies, Inc. Impact wrench
US4305471A (en) * 1979-04-19 1981-12-15 Rockwell International Corporation Simplified fastening technique using the logarithmic rate method
US4295377A (en) * 1979-07-12 1981-10-20 General Dynamics Corporation Fastener incorporating removable ultrasonic transducer
US4294122A (en) * 1979-07-12 1981-10-13 General Dynamics Corporation Fastener incorporating ultrasonic transducer
US4281987A (en) 1980-01-21 1981-08-04 Cavitron Corporation Ultrasonically driven low-speed rotary motor
US4333351A (en) * 1980-02-25 1982-06-08 Raymond Engineering Inc. Method and apparatus for measuring the residual tension in a stud or a bolt
US4344138A (en) 1980-11-05 1982-08-10 Frasier Cline W Digital air brake control system
US4471657A (en) * 1981-05-12 1984-09-18 Stresstel Corporation Digital ultrasonic stress measuring method and apparatus
LU84553A1 (en) * 1982-12-24 1984-10-22 Benoit De Halleux METHOD OF MEASURING CONSTRAINT IN A MEDIUM AND ELEMENT AND ASSEMBLY FOR IMPLEMENTING THE METHOD
DE3327964A1 (en) 1983-08-03 1985-02-28 Oskar Ing.(grad.) 7073 Lorch Mohilo Method of identifying connecting bolts according to type and/or tightening specification
US4602511A (en) * 1985-06-20 1986-07-29 J. A. Green Company Method for measuring fastener stress utilizing longitudinal and transverse ultrasonic wave time-of-flight
US4649753A (en) * 1986-04-08 1987-03-17 Multifastener Corporation Verification probe
DE3720625A1 (en) * 1987-06-23 1989-01-05 Krautkraemer Gmbh HARDNESS TEST DEVICE FOR HARDNESS TESTING UNDER LOAD
US4899591A (en) * 1987-09-11 1990-02-13 Sps Technologies, Inc. Ultrasonic load indicating member, apparatus and method
US4846001A (en) * 1987-09-11 1989-07-11 Sps Technologies, Inc. Ultrasonic load indicating member
US5291789A (en) * 1987-11-10 1994-03-08 Rotabolt Limited Load indicating
US4977898A (en) * 1988-02-25 1990-12-18 Hoffrel Instruments, Inc. Miniaturized encapsulated ultrasonic transducer
US5170277A (en) * 1988-05-11 1992-12-08 Symbol Technologies, Inc. Piezoelectric beam deflector
US5042015A (en) * 1989-09-01 1991-08-20 Quantronix, Inc. Measuring method and apparatus
US5018988A (en) * 1989-10-10 1991-05-28 Sps Technologies, Inc. Electrical contact mechanism for ultrasonic transducers on fasteners
US5029480A (en) 1990-02-05 1991-07-09 Sps Technologies, Inc. Ultrasonic load indicating member
US5216622A (en) * 1990-04-27 1993-06-01 Sps Technologies, Inc. Ultrasonic drive/sense circuitry for automated fastener tightening
US5220839A (en) * 1990-08-27 1993-06-22 Ultrafast, Inc. Ultrasonic load measuring device with control feature
US5131276A (en) * 1990-08-27 1992-07-21 Ultrafast, Inc. Ultrasonic load indicating member with transducer
JPH04166732A (en) 1990-10-30 1992-06-12 Suzuki Motor Corp Ultrasonic-wave axial-tension measuring apparatus
US5150714A (en) * 1991-05-10 1992-09-29 Sri International Ultrasonic inspection method and apparatus with audible output
US5211061A (en) * 1991-07-16 1993-05-18 Goodwin Jerry J Bolt clamping force sensor and clamping force validation method
CA2079517A1 (en) 1991-10-01 1993-04-02 Michael C. Ryan Method for identifying a penetrable member
US5343785A (en) * 1991-10-23 1994-09-06 Emerson Electric Co. Ultrasonic bolting control apparatus
US5303585A (en) * 1991-10-31 1994-04-19 Jtl Medical Corporation Fluid volume sensor
US5366026A (en) * 1992-08-28 1994-11-22 Nissan Motor Company, Ltd. Impact type clamping apparatus
US5807048A (en) 1992-09-03 1998-09-15 European Atomic Energy Community (Euratom) Sealing fastener with ultrasonic identifier and removal attempt indicator, and ultrasonic reading device for same
FR2696215B1 (en) 1992-09-25 1994-12-02 Serge Bras Assembly element and assembly method and machine.
US5242253A (en) * 1992-10-08 1993-09-07 Semblex Corporation Thread-forming screw
DE4243068C2 (en) * 1992-12-18 2003-06-26 Cooper Power Tools Gmbh & Co Pneumatic screwdrivers, in particular pulse or rotary screwdrivers
US6239737B1 (en) * 1994-07-15 2001-05-29 Micron Technology, Inc. Method and apparatus for attaching a radio frequency transponder to an object
CA2164187C (en) 1994-12-27 2000-02-01 Mohan L. Sanduja Protective coating on steel parts
US5726349A (en) * 1995-05-18 1998-03-10 United States Army Corps Of Engineers As Represented By The Secretary Of The Army Automated cone penetrometer
US6142023A (en) * 1995-11-17 2000-11-07 The Boeing Company Method and apparatus for applying a predetermined proof load to a cable and measuring the resultant cable length
JP3209082B2 (en) * 1996-03-06 2001-09-17 セイコーエプソン株式会社 Piezoelectric thin film element, method of manufacturing the same, and ink jet recording head using the same
AU3203797A (en) * 1996-05-03 1997-11-26 Ultrafast, Inc. A technique for eliminating ambiguity when making pulse-echo timing measurments
JPH1086074A (en) 1996-09-18 1998-04-07 Hitachi Ltd Bolt tightening control method
US6053906A (en) * 1997-06-25 2000-04-25 Olympus Optical Co., Ltd. Ultrasonic operation apparatus
US6211626B1 (en) * 1997-08-26 2001-04-03 Color Kinetics, Incorporated Illumination components
US6268796B1 (en) * 1997-12-12 2001-07-31 Alfred Gnadinger Radio frequency identification transponder having integrated antenna
US6311558B1 (en) * 1998-03-23 2001-11-06 The United States Of America As Represented By The Secretary Of Commerce Ultrasonic strain gage using a motorized electromagnetic acoustic transducer
US6078874A (en) * 1998-08-04 2000-06-20 Csi Technology, Inc. Apparatus and method for machine data collection
US6167758B1 (en) * 1998-10-23 2001-01-02 Max I. Fomitchev Method and apparatus for generating ultrasonic pulses with a specified waveform shape
US6341271B1 (en) 1998-11-13 2002-01-22 General Electric Company Inventory management system and method
US6350245B1 (en) * 1998-12-22 2002-02-26 William W. Cimino Transdermal ultrasonic device and method
NL1011591C1 (en) * 1999-03-18 2000-10-03 Konink Nedschroef Holding N V Screw bolt with measuring faces.
DE19917222A1 (en) 1999-04-16 2000-11-02 Schrauben Betzer Gmbh & Co Kg Screw and device for handling such a screw
US6598900B2 (en) * 1999-04-19 2003-07-29 Automotive Systems Laboratory, Inc. Occupant detection system
US6338600B2 (en) 1999-11-15 2002-01-15 Ejot Verbindungstechnik Gmbh & Co. Kg Self-tapping, corrosion-resistant screw with hardened tip
US6338716B1 (en) * 1999-11-24 2002-01-15 Acuson Corporation Medical diagnostic ultrasonic transducer probe and imaging system for use with a position and orientation sensor
US6791465B2 (en) 2000-07-11 2004-09-14 Sergei V. Blagin Tamper indicating bolt
US6633821B2 (en) * 2001-01-08 2003-10-14 Xerox Corporation System for sensing factory workspace
WO2002060650A2 (en) 2001-01-29 2002-08-08 Pat Technologies Limited Method and apparatus for determining when a fastener is tightened to a predetermined tightness by an impact tightening tool
US7467556B2 (en) 2001-01-29 2008-12-23 Innovation Plus, Llc Thread forming fasteners for ultrasonic load measurement and control
US7441462B2 (en) 2001-01-29 2008-10-28 Innovation Plus, Llc Load indicating member with identifying element
WO2002061292A1 (en) 2001-01-29 2002-08-08 Innovation Plus, Inc. Load indicating member with identifying mark
JP2002239939A (en) 2001-02-19 2002-08-28 Hitachi Engineering & Services Co Ltd Tightening torque controller for bolt
US6802681B2 (en) * 2001-11-20 2004-10-12 Itw Limited Fastening element
US6671185B2 (en) 2001-11-28 2003-12-30 Landon Duval Intelligent fasteners
US20030173098A1 (en) 2002-03-18 2003-09-18 Evergreen Technologies, Llc Portable multipurpose demolition tool
US6907944B2 (en) * 2002-05-22 2005-06-21 Baker Hughes Incorporated Apparatus and method for minimizing wear and wear related measurement error in a logging-while-drilling tool
EP1542834A2 (en) 2002-09-09 2005-06-22 Sigmasix L.L.C. Control system for discontinuous power drive
EP1549862B1 (en) 2002-09-19 2008-01-23 Innovation Plus, L.L.C. Thread forming fasteners for ultrasonic load measurement and control
SE526964C2 (en) 2003-12-29 2005-11-29 Atlas Copco Tools Ab Method for functional control of a pneumatic pulse nut puller and a power screwdriver system
DE102004003202B4 (en) 2004-01-22 2022-05-25 Robert Bosch Gmbh Handle with detection device
US20060102367A1 (en) 2004-02-04 2006-05-18 Etter Mark A Pneumatically powered rotary tool having linear forward and reverse switch
US20060004290A1 (en) 2004-06-30 2006-01-05 Smith Lowell S Ultrasound transducer with additional sensors
US20060157262A1 (en) 2005-01-14 2006-07-20 Jui-Yu Chen Power tool having presetable digital control of torque output
EP2008342B1 (en) 2006-04-06 2015-01-28 Innovation Plus, L.L.C. System for dynamically controlling the torque output of a pneumatic tool
EP2035217B1 (en) 2006-05-26 2018-07-25 Innovation Plus, L.L.C. Probe for fastener identification and ultrasonic load measurement
US7614303B2 (en) * 2007-03-27 2009-11-10 The United States Of America As Represented By The Secretary Of The Army Device for measuring bulk stress via insonification and method of use therefor
US20090188536A1 (en) * 2008-01-30 2009-07-30 Taiwan Supercritical Technology Co., Ltd. Ultrasonic cleaning device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5165831A (en) * 1989-10-06 1992-11-24 Cummins Engine Company Capscrew head markings for torque-angle tightening
US5970798A (en) * 1997-09-25 1999-10-26 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Ultrasonic bolt gage
US6186010B1 (en) * 1997-12-17 2001-02-13 Toyota Jidosha Kabushiki Kaisha Bolt for ultrasonic axial tension measurement

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7650792B2 (en) 2001-01-29 2010-01-26 Innovation Plus, Llc Load indicating member with identifying element
US7946179B2 (en) 2001-01-29 2011-05-24 Innovation Plus, Llc Thread forming fasteners for ultrasonic load measurement and control
US8033181B2 (en) 2001-01-29 2011-10-11 Innovation Plus, Llc Probe for fastener identification and ultrasonic load measurement

Also Published As

Publication number Publication date
US20100154183A1 (en) 2010-06-24
US7467556B2 (en) 2008-12-23
US7644627B2 (en) 2010-01-12
US20060130590A1 (en) 2006-06-22
WO2007089760A3 (en) 2008-09-25
US7946179B2 (en) 2011-05-24
US20090038402A1 (en) 2009-02-12

Similar Documents

Publication Publication Date Title
US7644627B2 (en) Thread forming fasteners for ultrasonic load measurement and control
US7441462B2 (en) Load indicating member with identifying element
US7650792B2 (en) Load indicating member with identifying element
US9483674B1 (en) RFID torque sensing tag system for fasteners
EP1549862B1 (en) Thread forming fasteners for ultrasonic load measurement and control
EP0441145B1 (en) Ultrasonic load indicating member
EP0381791B1 (en) Ultrasonic load indicating member, apparatus and method
US4899591A (en) Ultrasonic load indicating member, apparatus and method
EP3265712A1 (en) Systems and methods for strain detection in a coupling
US6009759A (en) Minimizing the effect of bending on ultrasonic measurements in a load-bearing member
CN102918371B (en) Device and method for indicating if a fastening element has reached a tensile yield limit load
US6581472B2 (en) Method of monitoring and controlling a screwing process
TWI551783B (en) Intelligent fastener, and fastener installation and inspection system
AU617770B2 (en) Ultrasonic load indicating member, apparatus and method
Fink et al. RFID Torque Sensing Tag System for Fasteners
JP2649837B2 (en) Fastener
Matvienko et al. Early Diagnostics of Damage and Fracture Zones in Composite Materials Using Brittle Strain Gauges and Acoustic Emission

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07709883

Country of ref document: EP

Kind code of ref document: A2