Ultrasonic tool off bolt detection system and related method

Abstract

An ultrasonic tool off bolt detection system for tightening first and second bolts in a multi -bolt joint. The detection system includes a drive tool configured to tighten the first and second bolts, first and second ultrasonic transducers mounted to the first and second bolts, respectively, and a central processor in communication with the drive tool. The central processor configured identify the first and second bolts and collect data regarding initial first and second bolt loads when the drive tool is engaged with the first and second bolts, respectively. The central processor configured to provide an indication to an operator to tighten the first bolt until a first bolt load that is approximately a first predetermined load. The central processor automatically initiating the drive tool to drive the second bolt after receiving a no load condition indicating the drive tool is removed from the first bolt.

Description

TITLE OF THE INVENTIONUltrasonic Tool Off Bolt Detection System and Related MethodBACKGROUND OF THE INVENTION

[0001] Assembly tools may be used to tighten bolts when assembling high precision joints having multiple bolts or fasteners, such as automotive engine cylinders, pipeline joints and aircraft joints. The assembly tools may utilize ultrasonic load measurement, and more specifically, handheld power tools for tightening bolts that have permanent ultrasonic transducers attached to the bolts to ensure that the bolts of the joint are precisely tightened to a specific load to ensure joint integrity and design strength.

[0002] Prior art systems include bolts with ultrasonic transducers mounted thereon for measuring and controlling bolt load during assembly, such as the bolts described in U.S. Patent No. 8,028,585 (‘“585 patent”). The ‘585 patent is incorporated herein by reference in its entirety. Prior art methods also include impact or impulse tools for use with bolts having ultrasonic transducers mounted thereon where the tools can be stopped at specified stopping loads or torques in a sequence of multiple-bolt joints, such as flanges and cylinder heads, such as the systems described in U.S. Patent No. 9,339,926 (“‘926 patent”). The ‘926 patent is incorporated herein by reference in its entirety. These single spindle systems result in slow assembly times for multi-bolt joints, and it would be desirable to design, develop and implement a system that improves cycle times for multiboltjoints while retaining the advantages of the systems and methods of the ’585 and ‘926 patents.

[0003] Prior art multi -bolt joints may alternatively be tightened by expensive multispindle tools that produce fast cycle times for high volume outputs. These multi-spindle tools are often custom built for a specific multi -bolt joint and are expensive. The volume of the same multi -bolt joints that must be tightened needs to be significant to justify the cost of designing, manufacturing and using these multi-spindle tools. For example, these multi-spindle tools may be utilized for tightening high volume joints in the automotive, main bearings, connecting rods or other components. It would be desirable to design, develop and implement a tool off bolt detection system for tightening a multi -bolt jointusing a single spindle hand held powered tool or a hand wrench that minimizes total assembly time when tightening bolts precisely to load.

[0004] The preferred invention addresses the shortcomings of the prior art bolt fastening systems and protocols by reducing assembly times and improving process reliability during precise tightening of bolts in multiple bolt joints.BRIEF SUMMARY OF THE INVENTION

[0005] Briefly stated, an objective of the ultrasonic tool off-bolt detection system of the preferred invention is to minimize total assembly time when tightening bolts with ultrasonic load measurement transducers in multi -bolt joints using a single spindle handheld powered tool or a hand wrench, by minimizing the time from completing a tightening operation on a first bolt to the start of a tightening operation on a second bolt in a predetermined bolt tightening sequence.

[0006] A further objective of the preferred invention is to use a low cost handheld tool without the need for an additional sensors to determine operator actions by using the existing ultrasonic load measurement electronics to determine when the operator has removed the tool from the first bolt and has placed the tool on the second bolt.

[0007] An additional objective of the preferred invention is to provide clear and timely direction to the operator to minimize operator errors and delays during the assembly process of a multi-bolt joint during a predetermined tightening sequence.

[0008] The preferred invention may also relate to an ultrasonic tool off bolt detection system and related method. The ultrasonic tool off bolt detection system may be utilized for tightening a first bolt having a first ultrasonic transducer mounted thereon and a second bolt having a second ultrasonic transducer mounted thereon in a multi -bolt joint in a predetermined sequence to predetermined loads. The ultrasonic tool off bolt detection system may include a drive tool configured to tighten the first and second bolts, a drive instrument mounted to the drive tool and selectively engageable with the first and second bolts for tightening the first and second bolts and a central processor in communication with the drive tool. The central processor may be configured to provide an indication to an operator to tighten the first bolt and to tighten the second bolt after acquiring a first bolt load that is approximately a first predetermined load. The central processor preparingthe drive tool to drive the second bolt as soon as the drive tool is removed from or is off the first bolt when contact is lost with the first ultrasonic transducer of the first bolt.

[0009] In another aspect, the preferred invention may be directed to a method of tightening a first bolt having a first ultrasonic transducer and a second bolt having a second ultrasonic transducer of a multi-bolt joint using an ultrasonic tool off bolt detection system having a drive tool, a drive instrument and a central processor. The method may include identifying the first bolt and the second bolt. The method may further include prompting an operator to engage and tighten the first bolt via the central processor and prompting the operator to engage and tighten the second bolt via the central processor. The central processor permits the drive tool to operate when the drive tool is engaged with the first bolt and the first bolt load is less than the first predetermined load. The central processor constantly monitors the first bolt load when the drive tool is operating, and the drive tool is engaged with the first bolt. The central processor stops the operation of the drive tool when the first bolt load is approximately the first predetermined load. The central processor automatically operating the drive tool to tighten the second bolt when the drive tool is engaged with the second bolt and a load less than the second predetermined load is sensed by the central processor.

[0010] In a further aspect, a preferred embodiment of the invention is directed to an ultrasonic tool off bolt detection system for tightening a first bolt having a first ultrasonic transducer to a first predetermined load and a second bolt having a second ultrasonic transducer to a second predetermined load in a multi -bolt joint in a predetermined sequence. The detection system includes a drive tool configured to tighten the first and second bolts, a drive instrument mounted to the drive tool and selectively engageable with the first and second bolts for tightening the first and second bolts and a central processor in communication with the drive tool. The central processor is configured to acquire bolt identification information of the first and second bolts. The central processor is configured to collect data regarding initial first and second bolt loads on the first and second bolts from the first and second ultrasonic transducers, respectively. The central processor is configured to provide an indication to an operator to tighten the first bolt after acquiring the bolt identification information, automatically stop tightening the first bolt when a first bolt load is approximately the first predetermined load, determine whenthe drive tool is removed from or off of the first bolt when a signal is lost from the first ultrasonic transducer indicating the drive tool is removed from the first bolt and initiate tightening of the second bolt after acquiring a second bolt load indicating that the drive tool is engaged with the second bolt.

[0011] Achieving high consistent and reliable clamp loads in multi -bolt joints during assembly is preferred for bolted joint integrity and eliminating costly and often disastrous failures. It is desirable to design, develop and implement a system that tracks a tightening sequence of the multi -bolt joint and acquires data regarding the clamping forces applied by the individual bolts in the joint to ensure consistent and desired clamping forces are applied by the individual bolts in the joint and the clamping forces are maintained as additional bolts in the joint are tightened. It is also desirable to design, develop and implement a multi -bolt joint tightening system and method that is simple, reliable and precise to facilitate accurate clamping forces on the fasteners in the multi -bolt joint with an efficient method.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0012] The foregoing summary, as well as the following detailed description of a preferred embodiment of the ultrasonic tool off bolt detection system and related method of the present application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the ultrasonic tool off bolt detection system and related method, there is shown in the drawings a preferred embodiment. It should be understood, however, that the application is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0013] Fig. 1 illustrates a side elevational, partial cross-sectional view of a tool off bolt detection system in accordance with a first preferred embodiment of the present invention;

[0014] Fig. 2 illustrates a side perspective view of a bolt that may be utilized with the tool off bolt detection system of Fig. 1;

[0015] Fig. 3 illustrates a top plan view of a multi -bolt joint that may be manipulated by the tool off bolt detection system of Fig. 1; and

[0016] Fig. 4 illustrates a side elevational, partial cross-sectional view of a tool off bolt detection system in accordance with a second preferred embodiment of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0017] Certain terminology is used in the following description for convenience only and is not limiting. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. The words "right", "left", "lower" and "upper" designate directions in the drawings to which reference is made. The words "inwardly" or “distally” and "outwardly" or “proximally” refer to directions toward and away from, respectively, the components of the ultrasonic tool off bolt detection system and related parts thereof. The words, “anterior”, “posterior”, “superior,” “inferior”, “lateral,” “proximal,” “distal,” and related words and / or phrases designate preferred positions, directions and / or orientations relative to the ultrasonic tool off bolt detection system and its components to which reference is made and are not meant to be limiting. The terminology includes the above-listed words, derivatives thereof and words of similar import.

[0018] It should also be understood that the terms “about,” “approximately,” “generally,” “substantially” and like terms, used herein when referring to a dimension or characteristic of a component of the preferred invention, indicate that the described dimension / characteristic is not a strict boundary or parameter and does not exclude minor variations therefrom that are functionally the same or similar, as would be understood by one having ordinary skill in the art. At a minimum, such references that include a numerical parameter would include variations that, using mathematical and industrial principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.), would not vary the least significant digit.

[0019] Referring to Figs. 1-3, an ultrasonic tool off bolt detection system and direct load measurement system, generally designated 1, enables precise assembly of a multiboltjoint 20 with all types of single spindle assembly tools or drive tools 18, including high speed impact wrenches 18. In critical bolted joints or multi -bolt joints 20, such as automotive , the fasteners or bolts 10 can be tightened in under a second (1 sec) to threesigma (3o) accuracies of less the three percent (3%), which is ten times (10X) better than that achievable with conventional methods based on detecting load applied to the bolt 10 during tightening. Additionally, a single drive tool 18, such as the preferred impact wrench 18, can be used to tighten the fasteners or bolts 10 in the multi -bolt j oint 20 sequentially in stages to ensure that the multi -bolt joint 20 is loaded evenly, avoiding component or gasket distortion. In the preferred exemplary embodiment, the multi-bolt joint 20 may include six (6) bolts 10, including first, second, third, fourth, fifth and sixth bolts 10a, 10b, 10c, lOd, lOe, 1 Of, although the multi -bolt joint 20 is not so limited and may include only the first and second bolts 10a, 10b. Each bolt 10a, 10b, 10c, lOd, lOe, lOf in the multi -bolt joint 20 may be tightened incrementally four or five times (4-5X) or more in a predetermined sequence or predetermined tightening sequence to achieve consistent and precise load for the bolts 10a, 10b, 10c, lOd, lOe, lOf in the multi-bolt joint 20. It is desirable to fasten these bolts 10a, 10b, 10c, lOd, lOe, lOf as quickly and reliably as possible, which is preferably accomplished by initiating the drive tool 18 to fasten the second bolt 10b as soon as contact is lost with the first bolt 10a, as is described in greater detail below.

[0020] In a high volume production assembly, multi-bolt joints 20 are usually tightened with expensive multi-spindle tools allowing concurrent loading or tightening of the bolts 10 at the same time, but for lower volume assemblies, such as in high performance engine assembly or maintenance, the impact wrench 18 is a more cost- effective and practical solution. The impact wrench 18 is not limited to being used for lower volume assemblies and may be utilized for nearly any multi -bolt joint 20 where precision, efficiency, reliability and consistency for the loads at each bolt 10a, 10b, 10c, lOd, lOe, lOf is desirable. In addition, the multi -bolt joint 20 is not limited to including the six (6) bolts 10a, 10b, 10c, lOd, lOe, lOf and may be comprised of nearly any multiboltjoint 20 having two (2) or more bolts 10.

[0021] The tool off bolt detection system and direct load measurement system 1 is preferably utilized with the load indicating fasteners or bolts 10 comprised of a fastener or bolt 10 with a permanent piezoelectric polymer film transducer 16 attached to one end, preferably a head end I la of the fastener 10, similar to those described in the ‘585 patent. The bolt 10 also preferably includes a threaded end 1 lb that engages female threads of anut or threaded hole of the multi -bolt joint 20. The load indicating fastener or bolt 10, preferably includes a two-dimensional high-density bar code 12 on top of an electrode 14. The six bolts 10a, 10b, 10c, lOd, lOe, lOf in the preferred six (6) bolt multi -bolt joint 20 each include an ultrasonic transducer 16, including first, second, third, fourth, fifth and sixth ultrasonic transducers 16a, 16b, 16c, 16d, 16e, 16f.

[0022] The load indicating fastener or bolt 10 includes the ultrasonic transducer 16 to provide an indication of the tensile load, stress, elongation or other characteristic of the bolt 10 during a tightening operation, as well as at various other times during the life of the multi-bolt joint 20. The ultrasonic tool off bolt detection system 1 may include a bolt probe 32 that operates to identify the specific fastener or bolt 10, such as the first, second, third, fourth, fifth and sixth bolts 10a, 10b, 10c, lOd, lOe, 1 Of, by optically reading the image of the bar code 12 on the ultrasonic transducer 16. The bolt probe 32 transmits the collected image of the bar code 12 to a central processor 26 to identify the specific fastener or bolt 10, 10a, 10b, 10c, lOd, lOe, lOf The central processor 26 preferably includes an on / off control that is used to turn off the impact wrench 18 when the desired or predetermined load has been achieved in identified the fastener or bolt 10, 10a, 10b, 10c, lOd, lOe, lOf. The central processor 26 also preferably constantly monitors the load on the bolt 10 by communicating with the ultrasonic transducer 16 through a contact member 36 in the drive tool 18 and automatically prepares the drive tool 18 for tightening the next bolt 10 in the predetermined sequence after a load for the particular bolt 10 reaches the bolt’s predetermined load. After the central processor 26 stops operation of the drive tool 18 and the operator moves the drive tool 18 off of the bolt 10, the contact member 36 loses contact with the ultrasonic transducer 16, thereby indicating the drive tool 18 is removed from the bolt 10. The removal of the drive tool 18 is detected by the central processor 26 when the contact member 36 loses contact with the ultrasonic transducer 16 and no load readings or data are being received by the central processor 26. Similarly, the central processor 26 automatically permits the drive tool 18 to operate when load data is again received, indicating that the contact member 36 is in contact with the ultrasonic transducer 16 of the next bolt 10.

[0023] The loss of a load signal after the detected bolt load is approximately the bolt’s predetermined load and the drive tool 18 is stopped from tightening by the centralprocessor 26 preferably results in the central processor 26 preparing the drive tool 18 to automatically tighten the next bolt 10 in the predetermined sequence when the trigger 18a is depressed and the central processor 26 receives a load from the ultrasonic transducer 16 of the next bolt 10. The automatic recognition that the drive tool 18 has been removed from the tightened bolt 10 by the central processor 26 results from a no load reading at the central processor 26. The immediate identification that the drive tool 18 is removed from the first bolt 18a and preparing the drive tool 18 to drive the next bolt 10 allows the operator to tightening bolts 10 quickly in the multi -bolt joint 20 with the impact wrench 18.

[0024] The impact wrench 18 or other tool is preferably comprised of a pneumatic tool with a pressurized air hose 30 providing pressurized air to the impact wrench 18. The impact wrench 18 or tool is not limited to being comprised of a pneumatic tool and may be comprised of an electric or other tool. The drive tool 18 or impact wrench 18 may, in a second preferred embodiment (Fig. 4), include an electrical switch 34, in addition to a pneumatic tool trigger 18a, although the electrical switch 34 and the trigger 18a are not limiting. The switch 34 may provide a signal or indication to the central processor 26 that the operator has finished tightening the last bolt 10, has placed the impact wrench 18 with a drive instrument or drive socket 22 on the head end 1 la of the next bolt 10 and is ready to start the next tightening, but the tool off bolt detection system and direct load measurement system 1 preferably does not utilize the switch 34 and the central processor 26 determines that the operator has removed the impact wrench 18 from the bolt 10 when the contact member 36 is no longer contacting the ultrasonic transducer 16 and no load data is received by the central processor 26.

[0025] The alternative switch 34 of the second preferred embodiment may be comprised of a contact switch 34 that provides a ready signal to the central processor 26 when the operator places the drive instrument or drive socket 22 on the head end 1 la of the bolt 10 and applies a force to the impact wrench 18 toward the bolt 10 such that the drive socket 22 contacts the switch 34. In the first preferred embodiment, the central processor 26 prepares the drive tool 18 to tighten the next bolt 10 in the sequence when the central processor 26 is not receiving load data resulting from the contact member 36 releasing from the ultrasonic transducer 16 and the drive tool 18 is then automaticallyprepared to drive the next bolt 10 in the predetermined sequence when a load is received by the central processor 26, which indicates that the drive tool 18 is engaged with the next bolt 10. The operator may immediately depress the trigger 18a to initiate the tightening of the next bolt 10 in the sequence when the load is detected. Alternatively, the operator may never release the trigger 18a and the drive tool 18 may immediately initiate tightening the next bolt 10 when the load of the next bolt 10 is detected, thereby increasing assembly speed. An object of the preferred invention is to automatically provide a reliable ready-to-start function for a load controlled portable tool or drive tool 18, such as the impact wrench 18, without tool modification or additional operations which add to overall assembly time for the multi -bolt joint 20. The first preferred invention, accordingly, eliminates the switch and tool modification that may be utilized in prior art tools that are utilized for tightening multi -bolt joints 20 by initiating or prompting the drive tool 18 to be ready to start tightening the next bolt 10 in the predetermined sequence when the load is detected upon contact between the contact member 36 and the ultrasonic transducer 16, which indicates that the drive tool 18 is engaged with the next bolt 10.

[0026] The ultrasonic tool off bolt detection system 1 may utilize the preferred bolts 10 with the permanent ultrasonic transducers 16 mounted thereto, such as i-Bolts, that may facilitate continuous pulse-echo time-of-flight measurements during assembly for each bolt 10, 10a, 10b, 10c, lOd, lOe, lOf of the multi -bolt joint 20. Contact to the permanent ultrasonic transducer 16 may be made with a spring-loaded electrical contact member 36 or contact pin 36 in the drive socket 22 or components of the impact wrench 18 proximate the drive socket 22. The contact member 36 may contact the top electrode 14 of the transducer 16 on the head end I la of the bolt 10. An electrical return path from the bolt 10, acting as the second electrode, is coupled through the drive socket 22. When the drive tool 18, such as the impact wrench 18, and the drive socket 22 are placed on the bolt 10, contact is made with the transducer 16 and ultrasonic load measurements may be collected by the central processor 26 through the communication wire 28 or wireless communication. The central processor 26 may automatically turn off the impact wrench 18 to stop the tightening of the bolt 10 when the predetermined load is reached or is approximately the acquired load of the bolt 10. The ultrasonic measurement process forthe bolt 10 is preferably stopped when the tightening operation is complete such that the tightening process may continue to the next bolt 10 in the sequence.

[0027] The preferred ultrasonic tool off bolt detection system 1 uses the ultrasonic measurement process to additionally detect when the tool, such as the impact wrench 18, is removed from the bolt 10 to automatically provide a ready -to-start signal to the central processor 26. After tightening of the bolt 10, such as the first bolt 10a, is completed when the first bolt load received by the central processor 26 is approximately the same as the first predetermined load and the results logged and displayed by the central processor 26 on a preferred display, the ultrasonic tool offbolt detection system 1 continues to make ultrasonic measurements on the bolt 10, such as the first bolt 10a. When the operator takes the impact wrench 18 off the bolt 10 and no load is received at the central processor 26 because the impact wrench 18 is disengaged from the bolt 10, the central processor 26 readies the tool 18 to tighten the next bolt 10, such as the second bolt 10b. The operator may pause to read the status of the last bolt 10 on the display of the central processor 26 and may leave the impact wrench 18 on the bolt 10. The central processor 26 is preferably reinitialized to prepare to tighten the next bolt 10 in the predetermined sequence after the operator removes the impact wrench 18 from the bolt 10 to tighten the next bolt 10, such as the second bolt 10b, and the ultrasonic tool offbolt detection system 1 may then read the load on the next bolt 10. Specifically, after the operator removes the impact wrench 18 from the first bolt 10a following confirmation that the first bolt load is approximately the first predetermined load, the central processor 26 collects no load because the contact member 36 is no longer in contact with the first ultrasonic transducer 16a. When the central processor 26 subsequently detects a load, the impact wrench 18 is connected to the second bolt 10b with the contact member 36 in contact with the second ultrasonic transducer 16b and the central processor 26 permits the impact wrench 18 to immediately tighten the second bolt 10b when the operator depresses the trigger 18a. The operator may continuously depress the trigger 18a during tightening of the multi -bolt joint 20 through the predetermined sequence such that the impact wrench 18 immediately begins to tighten the second bolt 10b as soon as the load of the second bolt 10b is acquired from the second ultrasonic transducer 16b and subsequent ultrasonic transducers 16 in the sequence.

[0028] The preferred method provides a reliable and fast ready -to-start next bolt 10 indication to the central processor 26, which is independent of operator delays and interruptions. The preferred ultrasonic tool off bolt detection system 1 avoids accidental retightening of the same bolt 10, as the central processor 26 does not permit operation of the impact wrench 18 when the detected bolt load is approximately the predetermined load in the central processor 26. If the operator chooses to interrupt the assembly process prior to completion of complete tightening of the multi -bolt joint 20, the operator can either leave the tool, such as the impact wrench 18, on the last bolt 10 that was being tightened or remove the impact wrench 18 from the bolt 10 and the central processor 26 will maintain the sequence for tightening the multi -bolt joint 20. After a preset time, the central processor 26 preferably stops with a timeout. The operator can later resume the assembly process from where the operator left off in the tightening sequence by communicating with the central processor 26, such as by pushing a continue button on the central processor 26, which will indicate to the operator which bolt 10 to tighten next in the sequence.

[0029] In a preferred but not limiting example of operating the ultrasonic tool off bolt detection system 1, the operator initially scans the bolts 10, 10a, 10b, 10c, lOd, lOe, lOf in a predetermined sequence or predetermined tightening sequence, which is the predetermined sequence stored in the central processor 26 and planned by a designer of the specific multi -bolt joint 20. As indicated above, the exemplary embodiment includes the first, second, third, fourth, fifth and sixths bolts 10a, 10b, 10c, lOd, lOe, lOf in a generally rectangular pattern, but the multi -bolt joint 20 is not so limited and may include nearly any design and configuration for a joint having at least two bolts 10 that are positioned relative to each other in nearly any design, such as a circle, square, straight line, zig-zag or other design or configuration. The operator initially scans each of the bolts 10a, 10b, 10c, lOd, lOe, 1 Of, preferably by scanning the bar codes 12 of the first, second, third, fourth, fifth and sixth transducers 16a, 16b, 16c, 16d, 16e, 16f using the bolt probe 32. The bolt probe 32 acquires identifications of the bolts 10a, 10b, 10c, lOd, lOe, lOf and transmits the identifications to the central processor 26. In addition, while scanning the bolts 10a, 10b, 10c, lOd, lOe, 1 Of and acquiring the bolt identification, the central processor 26 may visually and / or audibly confirm to the operator theidentification of the specific bolt 10a, 10b, 10c, l Od, lOe, lOf in the multi-bolt joint 20 that is scanned, preferably to indicate to the operator the predetermined tightening sequence and to confirm that each of the bolts 10a, 10b, 10c, lOd, lOe, 1 Of has been scanned.

[0030] Once the identifications of the bolts 10a, 10b, 10c, lOd, lOe, lOf are acquired and transmitted to the central processor 26, the central processor 26 may prompt the operator, visually on the display and / or audibly by voice prompts to commence the tightening sequence or to tighten the first bolt 10a.

[0031] To commence the predetermined tightening sequence, the operator positions the impact wrench 18 on the head end 1 la of the first bolt 10a and the contact member 36 contacts the first ultrasonic transducer 16, resulting in continuous transmission of first bolt load data from the first ultrasonic transducer 16a to the central processor 26. The central processor 26 may prevent the impact wrench 18 from operating if the operator attempts to tighten or mistakenly engages one of the other bolts 10b, 10c, lOd, lOe, lOf out of the predetermined sequence, but is not so limited. Once the central processor 26 confirms the operator has engaged the first bolt 10a by acquiring the first bolt load from the first ultrasonic transducer 16a, the operator may drive the impact wrench 18 by depressing the trigger 18a to apply additional load at the first bolt 10a. The central processor 26 preferably continuously collects loading data on the first bolt 10a while the trigger 18a is depressed and automatically stops the impact wrench 18 when the predetermined load for the first bolt 10a is approximately the same as the predetermined first bolt load. The central processor 26 may then stop the tightening and audibly and / or visually prompt the operator to move to the next bolt 10 in the predetermined tightening sequence or indicate to the operator to disengage the first bolt 10a, engage the second bolt 10b and tighten the second bolt 10b. The central processor 26 identifies removal of the impact wrench 18 from the first bolt 10a when is the contact member 36 is no longer in contact with the first ultrasonic transducer 16a, resulting in no load data being transmitted to the central processor 26.

[0032] The central processor 26 acquires the second bolt load on the second bolt 10b as soon as the contact member 36 engaged the second ultrasonic transducer 16b, resulting in the central processor 26 detecting or receiving a load from the second bolt 10b whenthe impact wrench 18 engages the second bolt 1 Ob. The operator may tighten the second bolt 10b by depressing the trigger 18a as soon as the central processor 26 receives the second bolt load from the second transducer 16b and if the trigger 18a remains continuously depressed by the operator the impact wrench 18 may start tightening as soon as the wrench 18 is engaged with the second bolt 10b. The central processor 26 may include a predetermined delay to facilitate full engagement of the drive socket 22 or impact wrench 18 with the second bolt 10b or any of the other bolts 10 such that the impact wrench 18 does not begin tightening until the bolt 10 is fully engaged. When the operator has engaged the second bolt 10b and depressed the trigger 18a, the central processor 26 continuously acquires the loading on the second bolt 10b through the second ultrasonic transducer 16b and stops tightening when the predetermined load of the second bolt 10b is approximately the second bolt load. Similar to the first and second bolts 10a, 10b, the central processor 26 continues to audibly and / or visually prompt the operator to move forward in the tightening sequence to tighten the next bolt 10 or the third, fourth, fifth and sixth bolts 10c, lOd, lOe, lOf in the sequence. The central processor 26 automatically initiates the impact wrench 18 for tightening the next bolt 10 in the predetermined sequence when the drive tool 18 is removed from the bolt 10. The central processor 26 also preferably permits tightening of the next bolt 10 in the predetermined sequence as soon as the contact member 36 contacts the next ultrasonic transducer 16, indicating that the impact wrench 18 is engaged with the next bolt 10. After the operator has tightened each of the bolts 10a, 10b, 10c, lOd, lOe, lOf in the multi -bolt joint 20 in an initial sequence, the central processor 26 may audibly and / or visually prompt the operator to again tighten the first bolt 10a and repeat the sequence. The sequence is repeated, by tightening or at least detecting the bolt load on each of the bolts 10a, 10b, 10c, lOd, lOe, lOf of the multi -bolt joint 20, as the loading on other bolts 10a, 10b, 10c, lOd, lOe, lOf in the multi -bolt joint 20 may change during the predetermined tightening sequence. The central processor 26 continues to prompt the operator audibly and / or visually to tighten the bolts 10a, 10b, 10c, lOd, lOe, 1 Of in the predetermined sequence until the bolt loads are approximately the predetermined loads on each of the bolts 10a, 10b, 10c, lOd, lOe, lOf

[0033] Following the initial pass of tightening the bolts 10a, 10b, 10c, lOd, lOe, l Of in the predetermined sequence, the central processor 26 may indicate audibly and / or visually to the operator that the specific bolt 10a, 10b, 10c, lOd, lOe, lOf that is engaged does not require further tightening because the bolt load of the bolt 10a, 10b, 10c, lOd, lOe, 1 Of has reached its predetermined load and the operator should move to tighten the next bolt 10a, 10b, 10c, lOd, lOe, lOf in the sequence or may indicate to move to another bolt 10a, 10b, 10c, lOd, lOe, lOf that is not in the predetermined sequence if the central processor 26 determines one of the other bolts 10a, 10b, 10c, lOd, lOe, 1 Of likely requires tightening.

[0034] The lack of a bolt load detected by the central processor 26 indicates the drive tool 18 was removed from the previous bolt 10 and tightening of the next bolt 10 may begin as soon as the contact member 36 contacts the ultrasonic transducer 16, indicating that the drive tool 18 is engaged with the next bolt 10. The central processor 26 may indicate to the operator that the tightening process for the multi -bolt joint 20 is complete when the bolt loads that are acquired for each of the bolts 10a, 10b, 10c, lOd, lOe, lOf in the sequence are approximately the predetermined bolt loads, respectively. The tool or impact wrench 18 is then ready to start a subsequent assembly. That is, the central processor 26 preferably audibly and / or visually indicates to the operator that the tightening sequence is complete when the impact wrench 26 sequentially identifies bolt loads of the bolts 10a, 10b, 10c, lOd, lOe, lOf in the predetermined sequence are at their predetermined load.

[0035] In operation, the ultrasonic tool off bolt detection system 1 is preferably utilized to tighten the fasteners or bolts 10 of the multi-bolt joint 20 in the predetermined sequence. The method may include tightening the first bolt 10a having the first ultrasonic transducer 16a and the second bolt 10b having the second ultrasonic transducer 16b of the multi -bolt joint 20 using the ultrasonic tool off bolt detection system 1. The system 1 may also be utilized to tighten the third, fourth, fifth and sixth bolts 10c, lOd, lOe, 1 Of, having the third, fourth, fifth and sixth ultrasonic transducers 16c, 16d, 16e, 16f, respectively. The multi -bolt joint 20 may have more or less bolts 10 than the exemplary six bolts 10a, 10b, 10c, lOd, lOe, lOf shown in Fig. 3.

[0036] Referring to Figs. 3 and 4, a second preferred embodiment of the ultrasonic tool off bolt detection system 1' has similar features when compared to the first preferred ultrasonic tool off bolt detection system 1 and like reference numbers are utilized to identify and describe like features with a prime symbol (') utilized to distinguish the second preferred ultrasonic tool off bolt detection system T from the first preferred ultrasonic tool off bolt detection system 1.

[0037] The fastener or bolt 10 of the second preferred embodiment does not include the ultrasonic transducer 16 mounted thereon but includes an ultrasonic sensor 24 associated with the drive tool 18’. In operation, the ultrasonic sensor 24 comes into acoustic communication with the head end 1 la of the fastener or bolt 10 during tightening to collect load data on the fastener or bolt 10.

[0038] Tightening of the exemplary multi -bolt joint 20 with the second preferred embodiment, may include initially identifying the first bolt 10a and an initial first bolt load by scanning the head end 1 la of the first bolt 10a by engaging the first bolt 10a with the drive tool 18’ so that the ultrasonic sensor 24 acoustically engaged the first bolt 10a. The first bolt 10a may be identified by using the bolt probe 32 and scanning a bar code 12 on the first bolt 10a or may be identified using a sensor on the drive tool 18 which may scan the bar code 12. The initial first bolt load may also be identified by collecting loading data with the sensor 24 when the drive tool 18' is engaged with the first bolt 10a. The second bolt 10b may be identified using the bolt probe 32 and scanning the bar code 12 of the second bolt 10b or may be identified using a sensor on the drive tool 18', preferably by scanning the bar code 12 of the second bolt 10b. The initial second bolt load may also be identified by the sensor 24 of the drive tool 18' when the drive tool 18' is engaged with the second bolt 10b. Similarly, the third, fourth, fifth and sixth bolts 10c, lOd, lOe, lOf may be identified by scanning or reading the respective bar codes 12 of the third, fourth, fifth and sixth bolts 10c, lOd, lOe, lOf with the bolt probe 32 or a sensor associated with the drive tool 18'. The initial third, fourth, fifth and sixth bolt loads may further be identified by scanning the third, fourth, fifth and sixth bolts 10c, lOd, lOe, lOf with the sensor 24 of the drive tool 18' when the drive tool 18' is engaged with the third, fourth, fifth or sixth bolts 10c, lOd, lOe, lOf, respectively. The identity of the first, second, third, fourth, fifth and sixth bolts 10a, 10b, 10c, lOd, lOe, lOf and the initial first,second, third, fourth, fifth and sixth bolt loads are transmitted to the central processor 26' and are preferably stored in the central processor 26'.

[0039] Once each of the bolts 10 in the multi -bolt joint 20 are identified and the identification is transmitted to the central processor 26', the operator is prompted to engage and tighten the first bolt 10a by the central processor 26'. The central processor 26' may prompt the operator to engage and tighten the first bolt 10a by an audible and / or a visual indication from the central processor 26'. For example, the central processor 26' may audibly indicate to the operator to “tighten bolt one” or an indication to tighten the first bolt 10a may be shown in a display of the central processor 26'. The operator 10 then preferably engages the first bolt 10a, the first bolt load is acquired and transmitted to the central processor 26', the central processor 26 compares the first bolt load to the first predetermined load, if the first bolt load is less than the first predetermined load the impact wrench 18' is permitted to tighten the first bolt 10a, the operator depresses the trigger 18a and the impact wrench 18 tightens the first bolt 10a to the first predetermined load. The impact wrench 18' may not operate if the impact wrench 18 engages one of the bolts 10 out of sequence from the predetermined sequence that is tracked by the central processor 26'. The central processor 26', therefore, permits the drive tool 18' to operate when the drive tool 18' is engaged with the first bolt 10a after the operator is prompted to tighten the first bolt 10a. During operation of the drive tool 18', the central processor 26 constantly monitors a first bolt load and compares the changing first bolt load to the first predetermined load while the drive tool 18' is engaged with the first bolt 10a. The central processor 26' stops operation of the drive tool 18' when the first bolt load is approximately the first predetermined load that is stored in the central processor 26'. After the first bolt load is approximately the first predetermined load, as determined by the central processor 26', the central processor 26' preferably stops operation of the drive tool 18' and prompts the operator to engage and tighten the second bolt 10b. The central processor 26 may prompt the operator to engage and tighten the second bolt 10b using similar audible or visual prompts as were described above or may otherwise prompt the operator to tighten the second bolt 10b. The drive tool 18' is removed from the first bolt 10a, resulting in loss of acoustic contact between the sensor 24 and the first bolt 10a, and the central processor 26' receives the loss of load signal from the ultrasonic sensor 24,indicating that the drive tool 18 was removed from the first bolt 1 Oa. The central processor 26' then automatically initiates the impact wrench 18 for tightening the second bolt 10b a soon as a bolt load is received by the central processor 26', indicating that the impact wrench 18' is engaged with the second bolt 10b because the sensor or ultrasonic sensor 24 is in acoustic communication with the second bolt 10a.

[0040] After the operator has tightened the first and second bolts 10a, 10b to approximately the first and second predetermined loads, the central processor 26' may prompt the user to tighten the additional bolts 10c, lOd, lOe, lOf in the predetermined sequence. The ultrasonic sensor 24 of the impact wrench or drive tool 18' preferably constantly acquires the load of the next bolts 10c, lOd, lOe, lOf by scanning the bolts 10c, lOd, lOe, lOf and transmitting the loads the central processor 26'. The central processor 26' initiates operation of the drive tool 18' if the acquired loads on the bolts 10c, lOd, lOe, lOf are less than the predetermined loads when the operator depresses the trigger 18a'. The operator does not necessarily need to depress the trigger 18a', as the central processor 26' may initiate operation of the drive tool 18' when the drive tool 18' is engaged with the next bolt 10c and the acquired load on the next bolt 10c is less than the predetermined load

[0041] Once the operator tightens each of the first, second, third, fourth, fifth and sixth bolts 10a, 10b, 10c, lOd, lOe, lOf in the predetermined sequence or the predetermined tightening sequence and the central processor 26' determines the first, second, third, fourth, fifth and sixth bolt loads are approximately the first, second, third, fourth, fifth and sixth predetermined loads, respectively, the central processor 26' preferably prompts the operator, audibly and / or visually, to tighten the first bolt 10a or to restart the predetermined tightening sequence a second time. The central processor 26' continues to prompt the operator to tighten the next bolt 10 in the predetermined sequence until the first, second, third, fourth, fifth and sixth bolt loads are approximately the first, second, third, fourth, fifth and sixth predetermined loads, respectively, through a single one of the predetermined sequences. The central processor 26' continues to repeat the predetermined sequence because loads on the bolts 10 in the multi -bolt joint 20 may change when other bolts 10 in the multi -bolt joint 20 are tightened, as is described herein.

[0042] The central processor 26, 26' preferably stores the predetermined sequence or the predetermined tightening sequence that comprises tightening the first bolt 10a, then the second bolt 10b, then the third bolt 10c, then the fourth bolt lOd, then the fifth bolt lOe and then the sixth bolt lOf of the multi -bolt joint 20 of the preferred embodiments. The tightening sequence is not necessarily limited to this described tightening sequence and may be otherwise designed and sequenced for tightening the fasteners or bolts 10 in the multi -bolt joint 20. For example, the multi -bolt joint 20 may have a different number of bolts 10 than the preferred multi -bolt joint 20 shown in Fig. 3, the predetermined tightening sequence may tighten a particular bolt 10 in the sequence more than once, may skip one or more of the bolts 10 in the multi -bolt joint 20 during a particular predetermined sequence or may be otherwise designed and configured for the constraints and particularities of the multi -bolt joint 20. In addition, the predetermined sequence may also include additional or alternative steps that are stored by the central processor 26, 26', such as prompting the operator to change the drive tool 18, 18' and use a different drive tool 18, 18', to change the drive instrument 22, 22' to tighten a particular bolt 10, to wait a predetermined amount of time before tightening the next bolt 10 in the predetermined sequence or to perform other tasks or collect additional data for transmittal to the central processor 26, 26' during the predetermined tightening sequence.

[0043] In the preferred embodiments, the predetermined sequence includes tightening the first bolt 10a, the second bolt 10b, the third bolt 10c, the fourth bolt lOd, the fifth bolt lOe, the sixth bolt lOf and then repeating this predetermined sequence until the first, second, third, fourth, fifth and sixth bolt loads are approximately the first, second, third, fourth, fifth and sixth predetermined loads, respectively. The predetermined sequence, therefore, preferably continues until the operator engages each of the bolts 10 in the sequence and the bolt loads are approximately the predetermined loads for each of the bolts 10 in the multi -bolt joint 20 without prompting the drive tool 18, 18' to tighten one of the bolts 10, because the bolt load is less than the predetermined load when the drive tool 18, 18' engages the specific bolt 10. In addition, the central processor 26, 26' determines that the drive tool 18, 18' is off or disengaged with the bolt 10 when the loss of load signal is detected when the drive tool 18, 18' is out of contact with the ultrasonic transducer 16 or the sensor 24 is out of contact with the bolt 10 that is being tightened.After detecting the loss of load signal, the central processor 26, 26' automatically initiates tightening authorization for the drive tool 18, 18' of the next bolt 10 in the predetermined sequence and automatically initiates tightening of the next bolt 10 when the bolt load is detected when the central processor 26 is in communication with the ultrasonic sensor 16 or the ultrasonic sensor 24 is in communication with the next bolt 10.

[0044] It will be appreciated by those skilled in the art that changes could be made to the preferred embodiment of the tool off bolt detection system and method described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiment disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the present description.

Claims

CLAIMSI / We claim:

1. An ultrasonic tool off bolt detection system for tightening a first bolt having a first ultrasonic transducer to a first predetermined load and a second bolt having a second ultrasonic transducer to a second predetermined load in a multi -bolt joint in a predetermined sequence, the detection system comprising: a drive tool configured to tighten the first and second bolts; a drive instrument mounted to the drive tool and selectively engageable with the first and second bolts for tightening the first and second bolts, the drive instrument including a contact member; and a central processor in communication with the drive tool, the central processor configured to acquire bolt identification information of the first and second bolts to identify the first and second bolts, the central processor configured to collect data regarding initial first and second bolt loads on the first and second bolts when the drive tool and the contact member are connected to the first and second bolts, respectively, the central processor configured to provide an indication to an operator to tighten the first bolt after acquiring the bolt identification information, automatically stop tightening the first bolt when a first bolt load is approximately the first predetermined load, determine when a loss of load signal is sensed by the ultrasonic sensor indicating that the drive tool is removed from the first bolt and to initiate tightening of the second bolt after acquiring a second bolt load indicating that the drive tool is engaged with the second bolt.

2. The detection system of claim 1, further comprising: a bolt probe configured to acquire the bolt identification information.

3. The detection system of claim 1, wherein the first ultrasonic transducer includes a first bar code and a first electrode and the second ultrasonic transducer includes a second bar code and a second electrode.

4. The detection system of claim 1, wherein the drive tool is comprised of an impact wrench.

5. The detection system of claim 4, wherein the impact wrench includes a pressurized air hose and a trigger.

6. The detection system of claim 1 wherein the drive instrument is comprised of a drive socket, the drive socket being removably mountable to the drive tool, the drive socket being comprised of a plurality of drive sockets having different sizes.

7. The detection system of claim 1, wherein the indication is comprised of an audible or a visual indication.

8. The detection system of claim 1, wherein the central processor is configured to automatically stop tightening the second bolt when a second bolt load is approximately the second predetermined load, the second bolt load acquired through the second ultrasonic transducer and transmitted to the central processor through the contact member.

9. The detection system of claim 1, wherein the predetermined sequence includes the first and second bolts and third, fourth, fifth and sixth bolts and the predetermined load includes the first predetermined load associated with the first bolt, a second predetermined load associated with the second bolt, a third predetermined load associated with the third bolt, a fourth predetermined load associated with the fourth bolt, a fifth predetermined load associated with the fifth bolt and a sixth predetermined load associated with the sixth bolt.

10. A method of tightening a first bolt having a first ultrasonic transducer and a second bolt having a second ultrasonic transducer of a multi -bolt joint using an ultrasonic tool off bolt detection system having a drive tool, a drive instrument, a contact member and a central processor, the method comprising: acquiring an initial first bolt load by contacting the first ultrasonic transducer with the contact member when the drive tool is engaged with the first bolt; transmitting the initial first bolt load of the first bolt to the central processor; comparing the initial first bolt load to a first predetermined load;driving the drive tool to tighten the first bolt while constantly acquiring a first bolt load through the first ultrasonic transducer and stopping the tightening of the first bolt when the first bolt load is approximately the first predetermined load; indicating to the operator to tighten the second bolt; acquiring a no load at the central processor indicating the drive tool is removed from the first bolt and the contact member is removed from the first ultrasonic transducer; and automatically driving the drive tool when a load is acquired by the central processor indicating the drive tool is engaged with the second bolt and the contact member is in contact with the second ultrasonic transducer.

11. The method of claim 10, further comprising: prompting the operator to engage and tighten the first bolt by at least one of an audible indication and a visual indication from the central processor.

12. The method of claim 10, further comprising: identifying a third bolt; and acquiring an initial third bolt load through a third ultrasonic transducer on the third bolt when the contact member is in contact with the third ultrasonic transducer; identifying a fourth bolt; acquiring an initial fourth bolt load through a fourth ultrasonic transducer on the fourth bolt when the contact member is in contact with the fourth ultrasonic transducer; identifying a fifth bolt; acquiring an initial fifth bolt load through a fifth ultrasonic transducer on the fifth bolt when the contact member is in contact with the fifth ultrasonic transducer; identifying a sixth bolt; and acquiring an initial sixth bolt load through a sixth ultrasonic transducer on the sixth bolt when the contact member is in contact with the sixth ultrasonic transducer, the first, second, third, fourth, fifth and sixth bolts comprising bolts of the multi -bolt joint.

13. The method of claim 12, wherein the central processor stores a predetermined tightening sequence, the predetermined tightening sequence comprisingtightening the first bolt, the second bolt, the third bolt, the fourth bolt, the fifth bolt and the sixth bolt in sequence.

14. The method of claim 12, wherein central processor stores a second predetermined load, the central processor prompting the operator to tighten the second bolt in the predetermined tightening sequence until the second bolt load is approximately the second predetermined load, the central processor automatically prompting the operator to tighten the third bolt when the second bolt load is approximately the second predetermined load.

15. The method of claim 14, wherein the central processor stores a third predetermined load, a fourth predetermined load, a fifth predetermined load and a sixth predetermined load, the central processor prompting the operator to tighten the first, second, third, fourth, fifth and sixth bolts in the predetermined tightening sequence until a third bolt load is approximately the third predetermined load, a fourth bolt load is approximately the fourth predetermined load, a fifth bolt load is approximately the fifth predetermined load and a sixth bolt load is approximately the sixth predetermined load.

16. The method of claim 10, wherein the first bolt is identified by scanning a first bar code of the first ultrasonic transducer.

17. The method of claim 10, wherein the central processor indicates to the operator to tighten the second bolt with an audible or visual indication.

18. The method of claim 10, wherein the drive tool is in communication with the central processor by a communication wire and the central processor is in communication with the first ultrasonic transducer when the contact member is in contact with the first ultrasonic transducer.

19. The method of claim 10, wherein the drive tool is comprised of an impact wrench and the drive instrument is comprised of a drive socket, the drive tool being driven by a pressurized air hose.

20. The method of claim 10, wherein the central processor constantly monitors the second bolt load when the drive tool is operating and the drive tool is engaged with the second bolt, the central processor stopping the operation of the drive tool when the second bolt load is approximately a second predetermined load.

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