TW201445056A - Intelligent fastener - Google Patents

Abstract

An intelligent fastener having a head and an externally threaded shank for threaded engagement with a structural member. The head has a recess formed in the top surface for mounting an RFID tag with a memory containing information specific to the fastener-such as fastener identification, specified torque value and other information-an antenna for enabling bidirectional communication with an RFID tag reader, and a torque value sensor for determining the torque applied to the fastener by a fastener installation tool. Once installed, the existing torque on a collection of fasteners is measured by using an RFID tag reader to scan the information stored in the memory of each fastener.

Description

Smart fastener

This invention relates to threaded fasteners. More particularly, the present invention relates to industrial threaded fasteners having intelligent characteristics.

Threaded fasteners have long been used to fasten countless types of mechanical parts together. Some examples of different types of mechanical parts that may be fastened together by threaded fasteners are structural members such as bridges, support beams in buildings, and structural members for aircraft structures. Typically, during installation, each threaded fastener is inserted into a hole in the grip to be gripped and threaded into a designated portion of the mating member, such as a nut secured to the mating member, or a thread formed in the mating member hole. In many applications, each fastener must be threaded to a specific amount of torque within a narrow tolerance band. Specific tolerances are usually part of the specifications created by a particular project and can be presented in paper form or electronically (such as in a flash drive or other computer readable memory) for use with a portable computer. Used, it can be transferred to the site. Both manual torque wrenches and power driven torque tools are typically used to tighten fasteners to values within a particular torque range. Typically, the installer The specifications must be consulted to determine the appropriate range of allowable torque values and then tighten the fasteners. Ideally, the installer manually establishes a record of each fastener installed by the field location and torque values, and this record is submitted to the inspector or other person or office responsible for the project data. However, this has never been done.

Many programs require that the installed fasteners be checked for suitable torque values immediately after installation, and then on a normal basis to ensure the safety of the entire structural assembly. This inspection and verification must be performed by a qualified individual (usually a trained inspector) with the original specification of the original specification, and usually applied by the inspector to each installed fastener with a torque wrench, a power driven torque tool or a torque measuring device. And done it manually. In addition, the inspector typically performs a visual measurement to determine if any fasteners are missing. The results of the inspection and verification must be reported to the designated individual or office, which maintains the inspection records for future reference.

Because the inspection process must be performed manually and visually on each individual fastener, the process is very time consuming and subject to human error, for example, due to the inability to properly apply the appropriate torque specification value to one or more fasteners, it is not possible to accurately Measure the torque on the specified fastener or fail to notify the fastener of the absence of the fastener from the site. Moreover, as noted above, the initial installation record of the fasteners is not often established for those responsible for maintaining the integrity and safety of the fastening structure.

The present invention includes threaded fasteners having intelligent characteristics that facilitate fastener mounting and tracking verification, as well as smart fastener systems and methods, It provides advantages that are not available for the installation and subsequent monitoring of structures that are secured together using threaded fasteners.

From a single device perspective, the present invention comprises a smart fastener comprising: a body member having a head and an externally threaded shank extending from the head; the head having a lower surface and an upper surface and a through hole formed therein The upper surface has a recess formed therein; an RFID (Radio Frequency Identification) tag mounted in the recess; an antenna mounted in the recess and connected to the RFID tag; a sensor having a body portion mounted in the recess and connected to the RFID a sensor; and the sensor has an arm extending away from the sensor body portion and terminating at one end, the arm portion being slidably received in the through hole and the end of the arm portion extending below the lower surface to allow the fastener to be inserted into the workpiece When the hole is in the hole, the end of the arm can contact the surface of the holed workpiece.

The RFID tag has a memory for storing fastener-specific information such as unique identification, specified torque values for the fastener, date of installation, site location where the fastener is installed, date of the original installation, and recent inspection of the fastener date.

In a preferred embodiment, the sensor includes a dual state microswitch that provides a binary torque state signal.

From a systemic point of view, the present invention is a fastener mounting and inspection system comprising: a fastener having a body member having a head and an externally threaded shank extending from the head; the head having a lower surface and An upper surface and a through hole formed therein; the upper surface has a recess formed therein; an RFID tag mounted in the recess, the RFID tag having a storage-specific fastening a memory of information; an antenna mounted in the recess and connected to the RFID tag; a sensor having a body portion mounted in the recess and coupled to the RFID tag; the sensor having a body portion extending away from the sensor and Ending at one end of the arm, the arm is slidably received in the through hole and the end of the arm extends below the lower surface such that when the fastener is inserted into the hole of the workpiece, the end of the arm can contact the workpiece with the hole a surface; and an RFID tag reader for querying the RFID tag and receiving information from the RFID tag.

The information stored in the RFID tag includes a unique identification for the fastener, a torque value specified for the fastener, a date for the original installation of the fastener, a site location where the fastener is installed, and a date of the fastener's most recent inspection. The information stored in the RFID tag can be updated when the RFID tag reader is properly used to transmit update information to the RFID tag.

The sensor preferably includes a dual state microswitch for sensing the torque state of the fastener.

The system further includes a fastener installation tool for driving the fastener into the threaded bore to a specified torque value. To this end, the fastener installation tool includes a torque control unit coupled to the RFID tag reader for limiting the torque applied by the fastener installation tool to the fastener to a torque value.

Fasteners made in accordance with the present invention provide several advantages over known threaded fasteners. First, when the installer is ready to install the fastener, the initial installation of the fastener to the correct torque specification is greatly facilitated by providing the correct torque information in the fastener RFID tag in a form that can be captured by the installation tool. In addition, the fasteners can be automatically driven to the appropriate by the installation tool The torque value, as well as the torque value, can be checked immediately after the fastener is installed to determine that the fastener is properly installed. Furthermore, the integration of the installation of a large number of fasteners can be quickly checked at any time using scanning inspection techniques, and any required correct action can be performed using an installation tool. In addition, the scanning inspection technique avoids the need to manually check the present value of each installed fastener, which substantially reduces the time required for the inspection process to be performed. Moreover, providing the fastener identification, type, specified torque value, site location, installation date, and inspection date information in the fastener in a form readable by the associated tag reader can result in a complete history compilation of the fastener installation plan and Saved in the host for future maintenance purposes. Finally, the above advantages are all affordable at a relatively low additional cost per fastener.

For a fuller understanding of the nature and advantages of the invention, reference should be

10‧‧‧fasteners

12‧‧‧ head

13‧‧‧Threaded handle

14‧‧‧Free end

15‧‧‧ concave upper surface

17‧‧‧RFID tags

18‧‧‧Antenna

19‧‧‧Upper body

20‧‧‧Micro Switch

22‧‧‧Switch starter arm

23‧‧‧through hole

24‧‧‧Free end

25‧‧‧ lower surface

26‧‧‧Conductors

27‧‧‧Conductor

30‧‧‧First structural member

31‧‧‧ hole

33‧‧‧Threaded Department

34‧‧‧ Structural components

40‧‧‧Power operation installation tool

41‧‧‧ real time

42‧‧‧RFID tag reader

43‧‧‧Power Drive Unit

44‧‧‧ Screwdriver bit

45‧‧‧Torque Control Unit

47‧‧‧Host

48‧‧‧ portable computer

1 is a perspective view of a preferred embodiment of a threaded fastener having intelligent features in conjunction with the present invention.

2 is a top plan view of the fastener of FIG. 1 showing the orientation of the smart component.

3 is a schematic illustration of the smart assembly of the fastener of FIG. 1.

4 is a side elevational elevational view, partially in section, of the fastener of FIG. 1 with the threaded shaft inserted through the aperture in the grasped structural member and the threaded shaft threaded onto the mating threaded portion of the other structural member.

Figure 5 is a power operation fastening for fastener installation and torque adjustment Schematic diagram of the installation tool.

Figure 6 is a block diagram illustrating the initial installation process for the fastener of Figure 1.

Figure 7 is a schematic illustration of a plurality of installed fasteners and a scanning inspection process.

Referring now to the drawings, Figures 1 and 2 illustrate a single fastener in accordance with the present invention. As shown in these figures, the fastener, generally designated with the symbol 10, has a head 12 and a threaded shank 13 terminating at the free end 14. The fastener head 12 has a central recess defined by a recessed upper surface 15 and a boundary wall surface 16 having sufficient depth and boundary dimensions to accommodate the RFID (Radio Frequency Identification) wafer 17, the antenna 18, and the upper body portion of the microswitch 20 19. Elements 17, 18 and 19 are all loaded by recessed upper surface 15 of head 12. The remainder of the microswitch 20 includes a switch actuating arm 22 that extends downwardly through a through bore 23 formed in the head 12 and terminates at the free end 24. The free end 24 of the switch actuating arm 22 terminates at a predetermined level below the lower surface 25 (shown in Figure 4) of the head 12 for the purposes described below. The relative diameters of the through hole 23 and the switch actuating arm 22 are selected such that the switch actuating arm 22 can stably reciprocate in the through hole 23.

Referring to FIG. 3, the components provided for the fastener 10 include a microswitch 20, an RFID wafer 17, and an antenna 18. The RFID chip 17 is a conventional RFID chip commonly referred to in the art as an RFID tag, preferably an Atmel type available from Atmel Corporation of San Jose, California. The ATA5570 integrated circuit, which combines the normal components required to enable bidirectional communication between the RFID integrated circuit 17 and the associated RFID tag reader via the antenna 18. The RFID wafer 17 further includes read and write memory segments for storing and permitting certain information about the fasteners 10 in response to interrogation of the associated RFID tag reader. The type of information will be explained more fully below. In addition, the RFID die 17 incorporates the desired power transfer circuit assembly to provide power from the electromagnetic interrogation signal to the integrated circuit component that receives the auto-associated RFID tag reader via the antenna 18. Because such components are well known, they will not be described in detail to avoid redundancy.

Microswitch 20 has two conductors 26, 27 (shown in Figures 2 and 3) that are coupled to the data input of RFID wafer 17. This enables the RFID wafer to monitor the binary state of the microswitch 20, for example, off or on. In the preferred embodiment, the microswitch 20 acts as a binary torque sensor for sensing whether the fastener 10 is tightened to the correct torque value.

Figure 4 illustrates a fastener incorporating the present invention that is partially mounted in two structural members. In this figure, elements 17, 18 and 20 are shown in dashed lines. As shown in this figure, the threaded shaft 13 is shown inserted through the hole 31 in the first structural member 30 to be gripped; and the threaded shaft 13 is also screwed into the threaded portion 33 of the other structural member 34. For a structural member 34 having a sufficient thickness, the threaded portion 33 of the structural member 34 can include a threaded bore formed in the structural member 34 as shown; alternatively, the threaded portion 33 can include a discontinuous threaded nut for permanent fixation (for example, by welding) to the opposite side of the structural member 34. In either case, the purpose of the threaded portion 33 is to provide The proper amount of clamping force between the first structural member 30 and the other structural member 34 when the fastener 10 is fully engaged.

As noted above, the fastener 10 must be clamped to a torque value that typically falls within a narrow range established by the gauge specifications. When the free end 24 of the arm 22 of the microswitch 20 engages the upper surface 35 of the structural member 30 and is driven upwardly in FIG. 4 to the calibrated position, the state of the fastener 10 is closed by the microswitch 20 (depending on circuit parameters or Turned on as indicated by the state change. This change in state can be detected by the RFID chip 17 and stored in the memory for subsequent use. After installation of the fastener 10, the value of the fastener torque can be checked by querying the RFID tag 17 with an associated RFID tag reader. If the torque has fallen below the lower limit established by the specification, the axial position of the microswitch arm 22 will have changed sufficiently that the state of the microswitch 20 will have returned to the out of torque range state. This change in switch state can be detected by the RFID tag 17, stored in the memory, and transmitted to the associated RFID tag reader after the inquiry.

Figure 5 is a schematic illustration of a power operated installation tool with reference numeral 40 for initial installation of the fastener 10 and subsequent adjustment of the fastener 10 to a suitable torque. As shown in this figure, the tool 40 preferably includes an instant meter 41 for providing instant installation information, an RFID tag reader 42 for reading information from the RFID tag 17 on which the fastener is to be mounted, and a power drive unit 43, A screwdriver bit 44 for providing a driving force to the fastening fastener 10; and a torque control unit 45 for controlling the power driving unit 43 to tighten the fastener 10 to a specified torque value. The installation tool 40 has a power input and a data communication conductive member for enabling the host 47 and The connection of the portable computer 48. The instant meter 41 is a conventional circuit for providing instant information. The RFID tag reader 42 is a conventional device capable of generating an RFID tag inquiry signal and receiving and processing information received from the reacted RFID tag 17. The power drive unit 43 is a conventional motor device that is used to provide a rotational driving force to the screwdriver bit 44. The screwdriver bit 44 is a conventional drive bit having a configuration that is compatible with the shape of the head 12 of the fastener 10 (e.g., a hex head). The torque control unit 45 is a conventional unit capable of controlling the maximum amount of torque generated by the power drive unit 43.

6 is a block diagram illustrating the use of the tool 40 for mounting and adjusting the torque setting of the fastener 10. As shown in this figure, the RFID tag reader 42 is placed in the vicinity of the fastener 10 and within the acceptance range. The RFID tag reader 42 is then operated to generate an inquiry signal for the fastener 10. Upon receipt of the inquiry signal, the RFID tag 17 of the fastener 10 responds to the RFID tag reader 42 by transmitting the requested information. The RFID tag reader 42 then checks the received information, which will include the unique identification of the fastener 10 and the desired torque value of the fastener 10. The RFID tag reader 42 then supplies the desired torque value to the torque control unit 45. When the torque value is received, the torque control unit 45 uses this torque value to control the operation of the power drive unit 43. The screwdriver bit 44 is manipulated on the head 12 of the fastener 10 and the power drive unit 43 is activated. When the screwdriver bit 44 is rotated by the power drive unit 43, the fastener 10 is driven into the threaded bore 33 of the structural member 34 (Fig. 4), pulling the structural members 30, 34 together until the torque control unit 45 senses The torque applied to the fastener 10 has reached a certain value. The operation of the power drive unit 43 is then torque controlled Unit 45 terminates. The RFID tag reader 42 then queries the RFID tag 17 of the fastener 10 and transmits the installation date information from the instant meter 41 to the RFID tag 17, which stores this information in the memory.

After the initial installation, the actual torque value of the now installed fastener 10 can be checked by the RFID tag reader 42 to query the RFID tag 17 of the fastener 10. When the response is received by the RFID tag reader 42, the received information will include the unique identification of the fastener 10, the desired torque value of the fastener 10, and the status of the microswitch 20. If the state of the microswitch 20 indicates that the torque value is incorrect, the initial installation process can be repeated until the torque value is correct. If the state of the initial installation process fails after one or more attempts, the installer can take selective action to determine the cause of the failure, such as checking the fastener and replacing it if a defect is found, inspecting the threaded hole 33 of the structural member 34 and determining Is it damaged?

After the installation process has been successfully determined, the information received by the RFID tag reader 42 from the RFID tag 17 of the currently installed fastener 10 can be transmitted to the host 47 for further processing and/or subsequent retrieval. This information will typically include the unique identification of the fastener 10, the desired torque value, whether the torque value of the fastener is within specification values, the date of installation and (selective) day, and the location of the fastener. At any stage of the installation process, the information received by the RFID tag reader 42 can be transmitted to the host 47 for further processing and/or subsequent retrieval. Similarly, host 47 can transmit data and instructions to RFID tag reader 42 to update the data of RFID tag 17, perform some data collection from RFID tag 17, or take other actions, such as scanning at different fasteners 10 in Collection of RFID tags 17.

Once a large number of fasteners 10 have been successfully installed, the integration of the installation can be quickly checked using the scanning inspection technique illustrated in FIG. Typically, this scan check process will be performed by an inspector who has more professional training than the installer. Moreover, the first scan inspection is typically performed shortly after the entire installation is completed or the installation of the predetermined set of fasteners has been completed. Figure 7 illustrates an array of 12 fasteners 10aa, 10ab, ..., 10cd, each fastener being mounted at a different location along the structural panel 30. A portable RFID tag reader 50 having the ability to query the RFID tag 17 carried by the respective fasteners 10aa, 10ab, ..., 10cd is manually scanned in the desired direction (left to right in Figure 7) throughout The array. Preferably, the RFID tag reader 50 has an antenna defining a transmitting/receiving area that includes a plurality of fasteners 10aa, 10ab, ..., 10cd such that a plurality of (three in the embodiment of Figure 7) fasteners Can be scanned simultaneously. Each of the response fasteners 10aa, 10ab, ..., 10cd supplies the requested information to the RFID tag reader 50, and this information can be used with a dedicated display incorporated into the RFID tag reader 50 or the portable computer monitor. Displayed to the inspector.

The required information will typically include a unique identification of each fastener in response to the inquiry signal generated by the RFID tag reader 50, the physical location of each response fastener on the board 30, the state of the torque microswitch 20, and the original installation. date. If the query for the specified fasteners 10aa, 10ab, ..., 10cd does not receive a response, this may indicate that the fastener is currently missing, or that the smart circuit component is invalid. Any condition can be repaired immediately or on a predetermined date by replacing the missing or failed fasteners 10aa, 10ab, ..., 10cd Reason. If the information received from the response fasteners 10aa, 10ab, ..., 10cd indicates that the torque exceeds the specification value, the inspector can use the above-described installation tool 40 with reference to FIG. 5 in an attempt to correct the problem. All information received by the RFID tag reader 50 can be shared with the host 47 and used for maintenance, history, and any other suitable purpose. The RFID tag reader 50 also transmits the inspection date and site location to each successfully queried RFID tag 17, which stores this information in memory.

The basic type of information of the RFID tag 17 that can be stored in the fastener 10 includes the identification of a particular fastener, which can be a serial number in a serial number or a combination of different characters in a large number of characters; a type name of the fastener; The specified torque of the fastener; the location of the fastener; the original installation date; and the date of the most recent inspection. It will be apparent to those skilled in the art that other types of information may also be stored in the RFID tag 17 depending on the needs of the specified application.

It is noted that the microswitch 20 in each fastener 10 has three possible states. A state of "1" may indicate that the fastener torque is within specification values, and a state of "0" may indicate that the fastener torque is not within specification values. The RFID tag reader 50 does not receive the value of the microswitch during the inquiry, which can be considered as a missing fastener 10, which can be determined by visual inspection, or an invalid microswitch, in this case, a new one. The fastener 10 can be mounted as a replacement.

It will now be apparent that a threaded fastener incorporating the intelligent assembly of the present invention as described above provides several advantages over known threaded fasteners. First, the initial installation of the fastener with the correct torque specification can be greatly facilitated by providing the correct torque information in the fastener RFID tag in the following form. This form can be obtained by the installation tool when the installer is ready to install the fastener. In addition, the fasteners are automatically driven to the appropriate torque by the mounting tool, and the appropriate torque can be checked immediately after the fastener is installed to determine that the fasteners are properly installed. In addition, the mounting integrity of a large number of fasteners can be quickly checked at any time using scanning inspection techniques, and any required corrective actions can be performed using an installation tool. In addition, the scanning inspection technique avoids the need to manually check the present value of each installed fastener, which substantially reduces the time required for the inspection process to be performed. Moreover, the provision of fastener identification, type, specified torque value, site location, installation date, and inspection date information in the fastener in a form readable by the associated tag reader enables the complete history of the fastener installation plan to be Compile and save in the host for future maintenance purposes. Finally, all of the above advantages are worth the relatively low additional cost per fastener.

While the above is a full and complete disclosure of the preferred embodiments of the present invention, various modifications, alternative structures and equivalents will occur to those skilled in the art. For example, although the invention has been described with reference to a particular RFID tag 17, other RFID tags can be used depending on the needs of the particular application. Moreover, while torque value sensors have been described as simple microswitches having two operational states, ie, binary devices, other types of torque sensors can be utilized, if desired, that provide for example a variable resistance or Variable value measurement of variable capacitance. Such a sensor may incorporate a complementary variable signal processing technique, such as the signal processing technique described in U.S. Patent Application Publication No. US 2007/0222583 A1, which incorporates the fastener 10, the disclosure of which is incorporated herein by reference. Therefore, the above description should not be construed as limiting the invention. The invention is defined by the appended claims.

10‧‧‧fasteners

12‧‧‧ head

13‧‧‧Threaded handle

14‧‧‧Free end

15‧‧‧ concave upper surface

17‧‧‧RFID chip

18‧‧‧Antenna

19‧‧‧Upper body

20‧‧‧Micro Switch

22‧‧‧Switch starter arm

23‧‧‧through hole

24‧‧‧ lower surface

16‧‧‧Boundary wall

Claims (20)

An intelligent fastener comprising: a body member having a head and an externally threaded shank extending from the head; the head having a lower surface and an upper surface and a through hole formed therein; the upper surface having a bore formed therein a recessed portion; an RFID (Radio Frequency Identification) tag mounted in the recess; an antenna mounted in the recess and connected to the RFID tag; a sensor having a body portion mounted in the recess and connected to the RFID tag; And the sensor has an arm portion extending away from the body portion of the sensor and terminating at one end, the arm portion being slidably received in the through hole and the end of the arm portion extending below the lower surface The end of the arm can contact the surface of the apertured workpiece when the fastener is inserted into the bore of the workpiece. The smart fastener of claim 1, wherein the RFID tag has a memory for storing information specific to the fastener. For example, the smart fastener of claim 2, at least some of which is stored in a readable section of the memory. A smart fastener as claimed in claim 2, wherein the information includes a unique identification for the fastener. A smart fastener as claimed in claim 2, wherein the information includes a torque value designated for the fastener. For example, the smart fastener of claim 2, wherein the information includes the date of installation of the fastener. A smart fastener as claimed in claim 1 wherein the information includes a site location for mounting the fastener. The smart fastener of claim 1, wherein the information includes an inspection date for the fastener. The smart fastener of claim 1, wherein the sensor comprises a dual state microswitch. A fastener mounting and inspection system, the system comprising: a fastener having a body member having a head and an externally threaded shank extending from the head; the head having a lower surface and an upper surface and formed therein a through hole having a recess formed therein; an RFID tag mounted in the recess, the RFID tag having a memory for storing information specific to the fastener; an antenna mounted in the recess and Connected to the RFID tag; a sensor having a body portion mounted in the recess and coupled to the RFID tag; the sensor having an arm portion extending away from the body portion of the sensor and terminating at one end, the arm a portion slidably received in the through hole and the end of the arm extending below the lower surface such that the end of the arm can contact the holed workpiece when the fastener is inserted into the hole of the workpiece And an RFID tag reader for querying the RFID tag and receiving the information from the RFID tag. The fastener installation and inspection system of claim 10, wherein the information includes a unique identification for the fastener. The fastener installation and inspection system of claim 10, wherein the information includes a torque value specified for the fastener. For example, the fastener installation and inspection system of claim 10, wherein the information includes the date of installation of the fastener. The fastener installation and inspection system of claim 10, wherein the information includes a site location for mounting the fastener. For example, the fastener installation and inspection system of claim 10, wherein the information includes the date of inspection for the fastener. A fastener mounting and inspection system according to claim 10, wherein the sensor comprises a dual state microswitch. The fastener mounting and inspection system of claim 10, wherein the RFID tag reader includes a transmitter for storing information in the memory of the RFID tag. The fastener mounting and inspection system of claim 10, wherein the RFID tag reader includes a transmitter for updating the information stored in the memory of the RFID tag. The fastener mounting and inspection system of claim 10, further comprising a fastener installation tool for driving the fastener into the threaded bore to a specified torque value. The fastener installation and inspection system of claim 19, wherein the information includes a torque value specified for the fastener, and wherein the fastener installation tool includes a torque control unit coupled to the RFID tag reader, The torque used to apply the fastener installation tool to the fastener is limited to the torque value.