Plug gauge for simultaneous multiple diameter measurements and related systems and methods

Abstract

To provide a plug gauge for taking multiple simultaneous diametric measurements of holes.SOLUTION: A plug gauge 10 includes: a housing 100 defining an internal space 102, multiple first openings 104, 106, and multiple second openings 108, 110; multiple first contact elements 112, 114 each received in corresponding one of the first openings; a first plunger 124 accommodated in the internal space and movable relative to the housing; a first sensor 130 sensing movement of the first plunger; multiple second contact elements 142, 144 each received in corresponding one of the multiple second openings; a second plunger accommodated in the internal space and movable relative to the housing; and a second sensor 160 sensing movement of the second plunger. The first plunger is biased to push the multiple first contact elements radially outward through the multiple first openings. The second plunger is biased to push the multiple second contact elements radially outward through the multiple second openings.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This application relates to hole gauging, and more particularly to plug gauges for simultaneously measuring multiple diameters of holes, and related systems and methods. [Background technology]

[0002] There are a variety of measurement tools used to measure the diameter of a cylindrical hole. This type of measurement tool typically includes a device that functions by contacting multiple diametrically opposed locations within the hole. Examples of this type of measurement tool include calipers, calipers with dial indicators, tubular inside micrometers, and Examples of conventional measurement tools include plug gauges or comparators. While satisfactory for some applications, conventional measurement tools suffer from several drawbacks. Some instruments are unable to measure deep into holes. Many other measurement tools are impossible to maintain in the proper position to make accurate measurements. Some measurement tools do not meet the tolerance requirements of certain applications. Furthermore, some measurement tools are unable to collect enough data to adequately characterize the hole dimensions. These problems are exacerbated when multiple different measurements are required to determine, for example, whether the hole is tapered, eroded, damaged, or otherwise uneven. Collecting a sufficient number of measurements is often time-consuming, which is undesirable for production purposes. For these reasons, research and development efforts by those skilled in the art continue in the field of internal hole measurement devices, and therefore, devices and methods designed to address the above-mentioned issues would be useful. Summary of the Invention

[0003] The following is a non-exhaustive list of examples of the subject matter of this disclosure, which may include both claimed and unclaimed examples.

[0004] In one example, the plug gauge of the present disclosure has an interior space and a longitudinal axis A H How to define The plug gauge includes a housing having a plurality of first openings communicating with the interior space and a plurality of second openings communicating with the interior space. The plug gauge also includes a plurality of first contact elements, each of which is at least partially received in a corresponding one of the plurality of first openings in the housing. The plug gauge further includes a first plunger, the first plunger being received in the interior space of the housing and extending along the longitudinal axis A of the housing. H First plunger axis A aligned with P1 Painting The first plunger is fixed to the first plunger axis A. P1 The plug gauge is movable relative to the housing along a longitudinal axis A of the housing. The first plunger is biased to engage the plurality of first contact elements and urge the plurality of first contact elements radially outward through the plurality of first openings. The plug gauge further includes a first sensor that detects movement of the first plunger relative to the housing. The plug gauge also includes a plurality of second contact elements. Each of the plurality of second contact elements is at least partially received in a corresponding one of the plurality of second openings in the housing. The plug gauge further includes a second plunger that is received in the interior space of the housing and is aligned along the longitudinal axis A of the housing. H Second plunger axis A aligned with P2 The above is defined. The second plunger is connected to the second plunger axis A. P2 The plug gauge further includes a second sensor configured to detect movement of the second plunger relative to the housing. The second plunger is biased to engage the second contact elements and urge the second contact elements radially outward through the second openings.

[0005] In one example, the plug gauge of the present disclosure has an interior space and a longitudinal axis AH How to define The housing includes a pair of first openings communicating with the interior space and a pair of second openings communicating with the interior space. The pair of second openings are spaced apart from the pair of first openings along the longitudinal axis A. H The plug gauge is displaced a predetermined non-zero distance D along the Furthermore, the longitudinal axis A H A first contact element axis A is approximately perpendicular to C1 is aligned along The plug gauge includes a pair of first contact elements, each of which is received in a corresponding one of the pair of first openings. The plug gauge further includes a first plunger, the first plunger being received in the interior space of the housing and extending along the longitudinal axis A of the housing. H First plunger axis A aligned with P1 The above is defined. The first plunger is P1 The plug gauge is movable relative to the housing along a second contact element axis A. The first plunger is biased to engage the pair of first contact elements. The plug gauge further includes a first sensor, which is housed in the interior space of the housing and detects movement of the first plunger relative to the housing. The plug gauge is movable relative to the housing along a second contact element axis A. C2 and a pair of second contact elements aligned along the second contact element axis A. C2 is the longitudinal axis A H is approximately perpendicular to , and the first contact element axis A C1 The plug gauge further includes a second plunger that is received in the interior space of the housing and is aligned with the longitudinal axis A of the housing. H Second plunger axis A aligned with P2The second plunger defines the second plunger axis A. P2 The second plunger is movable relative to the housing along a second sensor configured to detect movement of the second plunger relative to the housing.

[0006] In one example, a system of the present disclosure for simultaneously measuring the diameters of multiple holes formed in a structure includes a plug gauge sized to be received in the holes and a support connected to the plug gauge.

[0007] The disclosed method for simultaneously measuring the diameters of a plurality of holes formed in a structure includes: (1) a plug gauge is aligned along a longitudinal axis A H The plug gate is inserted into the hole while being disposed in a first orientation relative to the hole. (2) inserting a slit along the longitudinal axis A H The plug gauge is rotated around Rotate the longitudinal axis A H orienting the plug gauge in a second orientation relative to and (3) withdrawing the plug gauge from the hole.

[0008] Other examples of the plug gauges, systems, and methods of the present disclosure will become apparent from the following detailed description, the accompanying drawings, and the appended claims. [Brief explanation of the drawings]

[0009] [Figure 1] 1 illustrates an example of a plug gauge and associated system of the present disclosure for performing multiple simultaneous diameter measurements. FIG. [Figure 2] 2 is an elevational view showing a cross section of the probe portion of the plug gauge shown in FIG. 1. [Figure 3] 3 is an elevational view of a cross section of the probe portion shown in FIG. 2 rotated 90 degrees from the orientation shown in FIG. 2. [Figure 4]4 is an elevational view showing a cross section of the probe portion shown in FIG. 3 inserted into a hole formed in a structure. [Figure 5] FIG. 5 is a top view showing the probe unit and structure shown in FIG. [Figure 6] 10 is an elevational view showing a cross section of one variation of a plug gauge in which the probe portion of the disclosed plug gauge includes a linear potentiometer. FIG. [Figure 7] 7 is an elevational view of a cross section of the probe portion shown in FIG. 6 rotated 90 degrees from the orientation shown in FIG. 6. [Figure 8] 10 is an elevational view showing a cross section of another variation in which the probe portion of the plug gauge of the present disclosure includes a linear variable differential transformer. FIG. [Figure 9] 9 is an elevational view of a cross section of the probe portion shown in FIG. 8 rotated 90 degrees from the orientation shown in FIG. 8. [Figure 10] FIG. 10 is a perspective view showing details of the probe unit shown in FIG. 9. [Figure 11] FIG. 10 is an elevation view showing a cross section of another variation of the plug gauge of the present disclosure, in which the probe portion includes a linear encoder. [Figure 12] 12 is an elevational view of a cross section of the probe portion shown in FIG. 11 rotated 90 degrees from the orientation shown in FIG. 11. [Figure 13] 10 is an elevational view showing a cross section of another variation in which the probe portion of the plug gauge of the present disclosure includes a strain sensor in a first position. [Figure 14] 14 is an elevational view of a cross section of the probe portion shown in FIG. 13 rotated 90 degrees from the orientation shown in FIG. 13. [Figure 15] FIG. 15 is an elevational view showing details of the probe portion shown in FIG. 14. [Figure 16] FIG. 10 is an elevational view showing a cross section of another variation in which the probe portion of the plug gauge of the present disclosure includes a strain sensor in a second configuration. [Figure 17] FIG. 17 is an elevational view showing details of the probe portion shown in FIG. 16. [Figure 18] FIG. 1 is a flow diagram illustrating an example of a method of the present disclosure for performing multiple simultaneous diameter measurements. [Figure 19] FIG. 1 is a flow diagram illustrating an aircraft production and service method. [Figure 20] FIG. 1 is a block diagram illustrating an aircraft. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following detailed description refers to the accompanying drawings, which illustrate specific embodiments described in this disclosure. Other embodiments, including different structures and processes, may be used without departing from the scope of this disclosure. Similar reference numbers may be used to refer to the same features, elements, or components in different drawings.

[0011] The following are illustrative, non-exhaustive examples of the subject matter disclosed herein, which may or may not be recited in the claims. As used herein, an "example" means that one or more features, structures, elements, components, characteristics, and / or steps described in connection with the example are included in at least one embodiment and / or implementation of the subject matter disclosed herein. Thus, in this disclosure, terms such as "one example," "another example," "one or more examples," and similar terms may, but do not necessarily, refer to the same example. Furthermore, features characterizing one example may, but do not necessarily, include features characterizing other examples. Furthermore, features characterizing one example may, but do not necessarily, be combined with features characterizing other examples.

[0012] 1-17, an example of a plug gauge 10 is disclosed. The plug gauge 10, as shown in FIGS. 1, 4, and 5, is configured to be used to simultaneously measure the diameter of multiple holes 42 formed in a structure 40. The structure 40 may include or consist of a solid body having any shape and size depending on the particular purpose of the structure 40. The structure 40 may be formed from one of a variety of suitable materials, such as metal, plastic, and composite materials. The structure 40 may be a monolithic structure (a continuous, single piece of material) or a laminated structure incorporating multiple layers of material. The holes 42 may penetrate partially or entirely through the thickness of the structure 40. The holes 42 may be formed in the structure 40 by one of a variety of part-forming techniques, such as machining (e.g., drilling or boring), or may be formed in the structure during other subtractive manufacturing processes or during a forming process, such as an additive manufacturing process. Good too.

[0013] Referring to Figure 4, the holes 42 have a number of hole dimensions BD. In this document, the term "predetermined number" indicates one or more of the subject element. The hole dimension BD is defined by the linear distance between two diametrically opposed points on the interior surface defining the hole 42. In some cases, the hole dimension BD may be constant along the central longitudinal axis of the hole 42, such as with a cylindrical hole. In other cases, the hole dimension BD may vary along the central longitudinal axis of the hole 42, such as with a tapered, worn, or damaged hole. In some cases, the hole dimension BD may be constant at a given location along the central longitudinal axis of the hole 42 when viewed along the central longitudinal axis, such as with a hole having a circular cross-section. In other cases, the hole dimension BD may vary at a given location along the central longitudinal axis of the hole 42 when viewed along the central longitudinal axis, such as with a hole having an oval or elliptical cross-section.

[0014] 1-9, 11-14, and 16, in one or more examples, a plug gauge includes a housing 100. The housing 100 defines an interior space 102 (FIGS. 2-4) and has a longitudinal axis A H The housing 100 defines an interior space 102. The housing 100 includes a plurality of first openings 104, 106 (FIG. 2) that communicate with the interior space 102. The housing 100 includes a plurality of second openings 108, 110 (FIG. 3) that communicate with the interior space 102.

[0015] As shown in Figures 1, 4, and 5, the housing 100 is at least partially inserted into holes 42 formed in a structure 40 to simultaneously measure the diameters of multiple holes 42 using the plug gauge 10. As shown in Figures 2-4, 6-9, 11-14, and 16, the housing 100 houses and protects at least some of the various operating components of the plug gauge 10 in an interior space 102. As shown in Figures 4 and 5, the outer dimensions of the housing 100 are set to be similar to but smaller than the hole dimension BD of the hole 42 so that the housing 100 fits loosely into the hole 42.

[0016] 1-9, 11-14, and 16, in one or more examples, the plug gauge 10 includes a plurality of first contact elements 112, 114. Each first contact element 112, 114 of the plurality of first contact elements 112, 114 is at least partially received in a corresponding one of the plurality of first openings 104, 106 in the housing 100.

[0017] 4 and 5, the plurality of first contact elements 112, 114 are configured to engage with the inner surface defining the bore 42 when the housing 100 is inserted into the bore 42. Each of the plurality of first contact elements 112, 114 is movable relative to the housing 100 within a corresponding one of the plurality of first openings 104, 106. As shown in FIG. 2, the first contact element 112 is at least partially received in and movable within the first opening 104, and the first contact element 114 is at least partially received in and movable within the first opening 106.

[0018] 2-4, 11-14, and 16, in one or more examples, the plug gauge 10 includes a first plunger 124 housed in the interior space 102 of the housing 100. As shown in FIGS. 2 and 3, the first plunger 124 is oriented along the longitudinal axis A of the housing 100. H First plunger axis A aligned with P1 As shown in FIG. 4, the first plunger 124 is movable relative to the housing 100 along a first plunger axis AP1. The first plunger 124 is biased to engage the first plurality of contact elements 112, 114 and urge the first plurality of contact elements 112, 114 radially outward through the first plurality of openings 104, 106.

[0019] As used herein, when two or more axes are described as being "aligned" with one another, the description refers to the two or more axes being parallel to or coincident with one another.

[0020] The first plunger 124 moves within the housing 100 along a first plunger axis AP1. 2, when the first plunger 124 is biased into engagement with the plurality of first contact elements 112, 114, a portion of each of the first contact elements 112, 114 protrudes radially outward from the housing 100 through a corresponding one of the plurality of first openings 104, 106.

[0021] 4 and 5, the first plunger 124 urges the first contact elements 112, 114 through the first openings 104, 106 a distance sufficient to position and engage each of the first contact elements 112, 114 against the inner surface defining the bore 42 when the housing 100 is inserted into the bore 42. That is, when the first plunger 124 is biased to engage the first contact elements 112, 114, the linear distance between radially opposite ends of the first contact elements 112, 114 is greater than the bore dimension BD of the bore 42 (FIG. 4).

[0022] 4, when the housing 100 of the plug gauge 10 is inserted into the bore 42, the plurality of first contact elements 112, 114 move (e.g., are pushed) radially inward relative to the housing 100 through the plurality of first openings 104, 106 due to engagement with the inner surfaces defining the bore 42. As indicated by the directional arrows in FIG. 4, the first plunger 124 moves radially inward relative to the first plunger axis A. P1 1. The housing 100 moves linearly along the axis .

[0023] 1-4, 11-14, and 16, in one or more examples, the plug gauge 10 includes a first sensor 130 that detects movement of the first plunger 124 relative to the housing 100. In one or more examples, the first sensor 130 is configured to detect movement of the plurality of first contact elements 112, 114 relative to the housing 100 in addition to or instead of the above configurations.

[0024] The first sensor 130 detects the relative movement of the first plunger 124, the first plunger axis A P1 The first sensor 130 may include any one of a variety of devices capable of directly or indirectly detecting a relative change in the linear position of the first plunger 124 along the axis, a movement of the plurality of first contact elements 112, 114, or a change in the relative radial position of the plurality of first contact elements 112, 114. The first sensor 130 measures a physical quantity related to the movement of the first plunger 124 and / or the movement of the plurality of first contact elements 112, 114 and converts this measurement into a signal readable by an observer or a device. The signal generated by the first sensor 130 corresponds to the bore dimension BD of the bore 42 at a predetermined position of the plurality of first contact elements 112, 114 along the central longitudinal axis of the bore 42.

[0025] 1-9, 11-14, and 16, in one or more examples, the plug gauge 10 includes a plurality of second contact elements 142, 144. Each second contact element 142, 144 of the plurality of second contact elements 142, 144 is at least partially received in a corresponding one of the plurality of second openings 108, 110 in the housing 100.

[0026] 4 and 5, the plurality of second contact elements 142, 144 are configured to engage with an inner surface defining the bore 42 when the housing 100 is inserted into the bore 42. Each of the plurality of second contact elements 142, 144 is movable relative to the housing 100 within a corresponding one of the plurality of second openings 108, 110. As shown in FIG. 3, the second contact element 142 is at least partially received in the second opening 108 and movable within the opening, and the second contact element 144 is at least partially received in the second opening 108 and movable within the opening, and the second contact element 144 is at least partially received in the second opening 110. The member is at least partially received and movable within the opening.

[0027] 2-4, 6-9, 11-14, and 16, in one or more examples, the plug gauge 10 includes a second plunger 154 housed in the interior space 102 of the housing 100. As shown in FIGS. 2 and 3, the second plunger 154 is oriented along the longitudinal axis A of the housing 100. H Second plunger axis A aligned with P2 As shown in Figure 4, The plunger 154 is attached to the second plunger axis A. P2 The second plunger 154 is movable relative to the housing 100 along the second opening 108, 110. The second plunger 154 is biased to engage the second contact elements 142, 144 and urge the second contact elements 142, 144 radially outward through the second openings 108, 110.

[0028] The second plunger 154 is attached to the second plunger axis A. P2 3, when the second plunger 154 is biased into engagement with the plurality of second contact elements 142, 144, a portion of each of the second contact elements 142, 144 protrudes radially outward from the housing 100 through a corresponding one of the plurality of second openings 108, 110.

[0029] 4 and 5, the second plunger 154 urges the second contact elements 142, 144 through the second openings 108, 110 a distance sufficient to position and engage each of the second contact elements 142, 144 against the inner surface defining the bore 42 when the housing 100 is inserted into the bore 42. That is, when the second plunger 154 is biased to engage the second contact elements 142, 144, the linear distance between radially opposite ends of the second contact elements 142, 144 is greater than the bore dimension BD of the bore 42 (FIG. 4).

[0030] 4, when the housing 100 of the plug gauge 10 is inserted into the bore 42, the plurality of second contact elements 142, 144 move (e.g., are pushed) radially inward relative to the housing 100 through the plurality of second openings 108, 110 due to engagement with the inner surfaces defining the bore 42. As indicated by the directional arrows in FIG. 4, the second plunger 154 moves radially inward relative to the second plunger axis A. P2 1. The housing 100 moves linearly along the axis .

[0031] 1-4, 6-9, 11-14, and 16, in one or more examples, the plug gauge 10 includes a second sensor 160 that detects movement of the second plunger 154 relative to the housing 100. In one or more examples, the second sensor 160 is configured to detect movement of the plurality of second contact elements 142, 144 relative to the housing 100 in addition to, or instead of, the above configurations.

[0032] The second sensor 160 detects the relative movement of the second plunger 154, the second plunger axis A P2 The second sensor 160 may include any one of a variety of devices capable of directly or indirectly detecting a relative change in the linear position of the second plunger 154 along the axis, a movement of the plurality of second contact elements 142, 144, or a change in the relative radial position of the plurality of second contact elements 142, 144. The second sensor 160 measures a physical quantity related to the movement of the second plunger 154 and / or the movement of the plurality of second contact elements 142, 144 and converts this measurement into a signal readable by an observer or a device. The signal generated by the second sensor 160 corresponds to the bore dimension BD of the bore 42 at a predetermined position of the plurality of second contact elements 142, 144 along the central longitudinal axis of the bore 42.

[0033] In one example, the first sensor 130 and the second sensor 160 are the same type of sensor device. In another example, the first sensor 130 and the second sensor 160 are different types of sensor devices.

[0034] 2 and 3, the plurality of second openings 108, 110 are spaced apart from the plurality of first openings 104, 106 along the longitudinal axis A. H is displaced along the The plurality of second contact elements 142, 144 are spaced apart from the plurality of first contact elements 112, 114 along the longitudinal axis A H The plurality of second openings 108, 110 and the plurality of second openings 110 are displaced by a predetermined non-zero distance D along the The displacement distance D between the plurality of first openings 104, 106 (and between the plurality of second contact elements 142, 144 and the plurality of first contact elements 112, 114) allows diameter measurements of bore 42 to be taken simultaneously at multiple (e.g., two) different linear measurement locations of bore 42 along the central longitudinal axis of bore 42. The multiple linear measurement locations are linearly spaced apart by a distance substantially equal to the displacement distance D.

[0035] Referring to FIG. 5, in one example, the plurality of second openings 108, 110 are aligned along the longitudinal axis A. H The plurality of second contact elements 142, 144 are displaced about a longitudinal axis A by a non-zero angle θ relative to the plurality of first openings 104, 106. Similarly, the plurality of second contact elements 142, 144 are displaced about a longitudinal axis A H Centered around multiple The plurality of second openings 108, 110 are displaced by a non-zero angle θ relative to the plurality of first contact elements 112, 114. The displacement angle θ between the plurality of second openings 108, 110 and the plurality of first openings 104, 106 (and between the plurality of second contact elements 142, 144 and the plurality of first contact elements 112, 114) enables diameter measurements of the hole 42 to be taken simultaneously at multiple (e.g., two) different angular measurement locations of the hole 42 along its circumference. The multiple angular measurement locations are spaced apart by a non-zero angle that is substantially equal to the displacement angle θ.

[0036] 5, in one example, the non-zero angle θ is approximately 90 degrees. Because the non-zero angle θ is approximately 90 degrees, diameter measurements of holes 42 can be taken simultaneously at angular intervals of 90 degrees relative to each other. Other values ​​for the non-zero angle θ are also contemplated.

[0037] 1-5 , in one example, the housing 100 is generally tubular. The tubular shape of the housing 100 defines an interior space 102 within the housing 100, allowing at least some of the components of the plug gauge 10 (e.g., the plurality of first contact elements 112, 114, the first plunger 124, the plurality of second contact elements 142, 144, and the second plunger 154) to be enclosed and protected within the housing 100. Furthermore, the tubular shape of the housing 100 allows the housing 100 to be inserted (at least partially) into the bore 42, which has a generally circular cross-section when viewed along the central longitudinal axis of the bore 42.

[0038] 1-9, 11-14, and 16, in one or more examples, housing 100 defines outer surface 101. A portion of first contact elements 112, 114 and a portion of second contact elements 142, 144 protrude radially outward from outer surface 101. The outer dimension of outer surface 101 is set to approximate but be smaller than bore dimension BD of bore 42 so that housing 100 fits loosely in bore 42.

[0039] As shown in FIG. 2, when the first plunger 124 is biased to engage the plurality of first contact elements 112, 114, a greater portion of each of the first contact elements 112, 114 protrudes radially outward from the outer surface 101. As shown in FIGS. 4 and 5, when the housing 100 is inserted into the bore 42, a smaller portion of each of the first contact elements 112, 114 protrudes radially outward from the outer surface 101. As shown in FIG. 2, when the second plunger 154 is biased to engage the plurality of second contact elements 142, 144, a larger portion of each of the second contact elements 142, 144 protrudes radially outward from the outer surface 101. As shown in FIGS. 4 and 5, when the housing 100 is inserted into the bore 42, a smaller portion of each of the second contact elements 142, 144 protrudes radially outward from the outer surface 101.

[0040] In one example, outer surface 101 is substantially cylindrical, and the cylindrical shape of outer surface 101 allows housing 100 to be inserted (at least partially) into bore 42, which has a generally circular cross-section when viewed along the central longitudinal axis of bore 42.

[0041] 1-9, 11-14, and 16, in one or more examples, the plurality of first contact elements 112, 114 are aligned along a first contact element axis A. C1 The first contact element 112 comprises two first contact elements 112, 114 aligned along a first contact element axis A (FIGS. 2 and 5). C1 is the longitudinal axis A H As shown in FIGS. 2 and 5, the two first contact elements 112, 114 is the first contact element axis A C1 , a first dimensional measurement can be taken at a predetermined location along the central longitudinal axis of bore 42 between two diametrically opposed points on the interior surface defining bore 42.

[0042] In other examples, the plurality of first contact elements 112, 114 comprises four, six, or eight first contact elements 112, 114, each pair of which is aligned along a respective first contact element axis A C1 are aligned along the

[0043] 1-9, 11-14, and 16, in one or more examples, the plurality of second contact elements 142, 144 are arranged along a second contact element axis A. C2 The second contact element 142 comprises two second contact elements 142, 144 aligned along a second contact element axis A (FIGS. 3 and 5). C2 is the longitudinal axis A H As shown in FIGS. 3 and 5, two second contact elements 142, 144 is the second contact element axis A C2 , a second dimensional measurement can be taken at a predetermined location along the central longitudinal axis of bore 42 between two diametrically opposed points on the inner surface defining bore 42.

[0044] In other examples, the plurality of second contact elements 142, 144 comprises four, six, or eight pairs of second contact elements 142, 144, each pair of which has a respective second contact element axis A C2 are aligned along the

[0045] As shown in FIGS. 2 and 3, in one example, the second contact element axis A C2 is the first contact element axis A C1 from the longitudinal axis A H The second contact element axis A is displaced by a predetermined non-zero distance D along the second contact element axis A. C2 and the first contact element axis A C1 The displacement distance D between the hole 42 and the The first and second dimensional measurements can be taken at a number of different locations.

[0046] As shown in FIG. 5, in one example, the second contact element axis A C2 is the first contact element axis A C1 The second contact element axis A is arranged to form a non-zero angle θ with respect to the second contact element axis A. C2 and the first contact element axis A C1 The displacement angle θ between allows the first and second dimensional measurements to be taken at a number of different angular positions along the circumference of the hole 42. In one example, the non-zero angle θ is approximately 90 degrees. Other values ​​for the non-zero angle θ are also contemplated.

[0047] 2-4, 6-9, 11-14, and 16, in one or more examples, each of the first contact elements 112, 114 of the plurality of first contact elements 112, 114 is substantially spherical. Similarly, in one example, each of the second contact elements 142, 144 of the plurality of second contact elements 142, 144 is substantially spherical. The substantially spherical shapes of the first contact elements 112, 114 and the second contact elements 142, 144 allow for smoothly contoured contact surfaces that engage with edges of the structure 40 that define the ends of the hole 42 when the housing 100 is inserted into the hole 42. The smoothly contoured contact surfaces prevent the first contact elements 112, 114 and the second contact elements 142, 144 from getting caught on the edges of the hole 42.

[0048] In other examples, each of the plurality of first contact elements 112, 114 and / or each of the plurality of second contact elements 142, 144 may have any of a variety of other shapes. For example, each of the first contact elements 112, 114 and / or each of the second contact elements 142, 144 may be generally cylindrical with rounded or hemispherical ends.

[0049] 2-4, 6-9, 11-14, and 16, in one or more examples, each first contact element 112, 114 of the plurality of first contact elements 112, 114 is connected to the housing 100 by a corresponding retainer 116, 118 (FIG. 2) of the first contact element 112, 114. Similarly, in one example, each second contact element 142, 144 of the plurality of second contact elements 142, 144 is connected to the housing 100 by a corresponding retainer 146, 148 (FIG. 3) of the second contact element 142, 144.

[0050] 2, 6, 8, 11, 13, and 16, each first retaining portion 116, 118 connects each of the first contact elements 112, 114 to the housing 100 and retains each of the first contact elements 112, 114 within the corresponding first opening 104, 106. Each first retaining portion 116, 118 may include or consist of any suitable flexible body configured to support each of the first contact elements 112, 114 within the corresponding first opening 104, 106 while allowing each of the first contact elements 112, 114 to move radially inward and outward through the corresponding first opening 104, 106.

[0051] 3, 4, 7, 9, 12, and 14, each second retaining portion 146, 148 connects each of the second contact elements 142, 144 to the housing 100 and retains each of the second contact elements 142, 144 within the corresponding second opening 108, 110. Each second retaining portion 146, 148 may include or consist of any suitable flexible body configured to support each of the second contact elements 142, 144 within the corresponding second opening 108, 110 while allowing each of the second contact elements 142, 144 to move radially inward and outward through the corresponding second opening 108, 110.

[0052] In one example, one end of each first retaining portion 116, 118 is connected to the inner surface of housing 100, and the opposite end of each first retaining portion 116, 118 is connected to the respective first contact elements 112, 114. Similarly, in one example, one end of each second retaining portion 146, 148 is connected to the inner surface of housing 100, and the opposite end of each second retaining portion 146, 148 is connected to the respective second contact elements 142, 144. In one example, each first retaining portion 116, 118 is connected to housing 100 by a respective first mechanical fastener 120, 122 (FIG. 2). Similarly, in one example, each second retaining portion 146, 148 is connected to housing 100 by a respective second mechanical fastener 150, 152 (FIG. 3).

[0053] 2-4, 6-9, 11-14, and 16, in one or more examples, the plug gauge 10 includes a first biasing element 170 positioned to bias the first plunger 124 into engagement with the plurality of first contact elements 112, 114. The first biasing element 170 is configured to bias the first plunger 124 in a direction perpendicular to the first plunger axis A. P1 , toward the plurality of first contact elements 112, 114, thereby enabling the first plunger 124 to urge each first contact element 112, 114 radially outward through each of the first openings 104, 106. When the housing 100 is inserted into the bore 42, the biasing force of the first biasing element 170 overcomes the force exerted radially inward on the plurality of first contact elements 112, 114 by the inner surfaces defining the bore 42, causing the first plunger 124 to move linearly in a direction opposite to the direction of the biasing force.

[0054] 2-4, 6-9, 11-14, and 16, in one example, first biasing element 170 includes or consists of a spring 172. In other examples, first biasing element 170 includes any one of various types of suitable biasing mechanisms.

[0055] 2-4, 6-9, 11-14, and 16, in one or more examples, the plug gauge 10 includes a second biasing element 174 positioned to bias the second plunger 154 into engagement with the plurality of second contact elements 142, 144. The second biasing element 174 is configured to bias the second plunger 154 in a direction perpendicular to the second plunger axis A. P2 110 toward the plurality of second contact elements 142, 144, thereby enabling the second plunger 154 to urge each second contact element 142, 144 radially outward through each of the second openings 108, 110. When the housing 100 is inserted into the bore 42, the biasing force of the second biasing element 174 overcomes the force exerted radially inward on the plurality of second contact elements 142, 144 by the inner surfaces defining the bore 42, causing the second plunger 154 to move linearly in a direction opposite to the direction of the biasing force.

[0056] In one example, the second biasing element 174 includes or consists of a spring. In other examples, the second biasing element 174 includes any one of various types of suitable biasing mechanisms. In one example, the first biasing element 170 and the second biasing element 174 are the same type of biasing mechanism. In other examples, the first biasing element 170 and the second biasing element 174 are different types of biasing mechanisms. In one example, at least one of the first biasing element 170 and the second biasing element 174 is disposed in the interior space 102 of the housing 100. In one example, both the first biasing element 170 and the second biasing element 174 are disposed in the interior space 102 of the housing 100.

[0057] 2 and 3, in one example, plug gauge 10 includes a set screw 176 that threadably engages housing 100. First biasing element 170 is disposed between set screw 176 and first plunger 124. Set screw 176 allows for selective adjustment of the biasing force applied to first plunger 124 by first biasing element 170. For example, rotating set screw in a first rotational direction compresses spring 172, increasing the biasing force, and rotating set screw in a second rotational direction opposite the first rotational direction decompresses spring 172, decreasing the biasing force.

[0058] 2 and 3, in one example, the first plunger 124 includes a head portion 126 that engages with the plurality of first contact elements 112, 114. The head portion 126 includes an inclined surface 128. The inclined surface 128 of the head portion 126 of the first plunger 124 forms a smoothly contoured contact surface that engages with each of the first contact elements 112, 114. The inclined surface 128 allows the first plunger 124 to be aligned with the first plunger axis A. P1 When the first plunger 124 moves along the first contact elements 112, 114, the head 126 of the first plunger 124 can be prevented from getting caught on the first contact elements 112, 114.

[0059] Although not explicitly shown, in one example, the second plunger 154 includes a head portion that engages with the plurality of second contact elements 142, 144. The head portion includes an inclined surface. The inclined surface of the head portion of the second plunger 154 forms a smoothly contoured contact surface that engages with each of the second contact elements 142, 144. The inclined surface allows the second plunger 154 to move in a direction perpendicular to the second plunger axis A. P2 When the second plunger 154 moves along the second contact elements 142, 144, the head portion of the second plunger 154 can be prevented from getting caught on the second contact elements 142, 144.

[0060] Referring to FIG. 1, in one example, the probe portion 12 of the plug gauge 10 includes a housing 100, a plurality of first contact elements 112, 114, a first plunger 124, a first sensor 130, and a housing 100. , a plurality of second contact elements 142, 144, a second plunger 154, and a second sensor 160. The plug gauge 10 further includes a coupling portion 14 connected to the probe portion 12. The probe portion 12 of the plug gauge 10 is formed by a portion of the plug gauge 10 intended to be inserted into the hole 42. The coupling portion 14 is configured to enable connection of the probe portion 12 to the support 20.

[0061] 1-4, 6-9, 11-14, and 16, in one or more examples, at least one of the first sensor 130 and the second sensor 160 is disposed in the interior space 102 of the housing 100. In one or more examples, the first sensor 130 and the second sensor 160 are both disposed in the interior space 102 of the housing 100. By disposing the first sensor 130 and / or the second sensor 160 in the interior space 102 of the housing 100, an enclosed operating environment can be created and the first sensor 130 and the second sensor 160 can be protected during use of the plug gauge 10. Furthermore, by disposing the first sensor 130 and / or the second sensor 160 in the interior space 102 of the housing 100, the plug gauge 10 can simultaneously perform two separate measurements of the hole 42 at two different positions along the longitudinal center axis of the hole 42 using two separate measurement assemblies, namely, (1) a plurality of first contact elements 112, 114, a first plunger 124, and a first sensor 130, and (2) a plurality of second contact elements 142, 144, a second plunger 154, and a second sensor 160.

[0062] 1-4 generally, and 6-12 specifically, in one example, at least one of the first sensor 130 and the second sensor 160 includes a linear position sensor 200, 300, 400. In one example, the first sensor 130 and the second sensor 160 both include a linear position sensor 200, 300, 400. The linear position sensor 200, 300, 400 includes one of a variety of devices capable of measuring the respective positions of the first plunger 124 and the second plunger 154. The linear position sensor may be an absolute position sensor or a relative position sensor (e.g., a displacement sensor).

[0063] As shown in FIG. 4 , in one example, engagement with the inner surfaces defining the bore 42 causes the first plurality of contact elements 112, 114 to move radially inward through the first plurality of openings 104, 106. The radial inward movement of the first plurality of contact elements 112, 114 causes the first plunger 124 to move, thereby changing the position of the first plunger 124. As shown in FIGS. 6-12 , in one or more examples, the linear position sensors 200, 300, 400 of the first sensor 130 detect the linear position or displacement of the first plunger 124. The linear position sensors 200, 300, 400 of the first sensor 130 convert the linear position or displacement of the first plunger 124 from a reference (e.g., a zero or null position) into a proportional electrical signal. The signals generated by the linear position sensors 200 , 300 , 400 are indicative of the bore dimension BD of the bore at predetermined positions of the first plurality of contact elements 112 , 114 along the central longitudinal axis of the bore .

[0064] As shown in FIG. 4 , in one example, engagement with the inner surface defining the bore 42 causes the plurality of second contact elements 142, 144 to move radially inward through the plurality of second openings 108, 110. The radial inward movement of the plurality of second contact elements 142, 144 causes movement of the second plunger 154, thereby changing the position of the second plunger 154. As shown in FIGS. 6-12 , in one or more examples, the linear position sensors 200, 300, 400 of the second sensor 160 detect the linear position or displacement of the second plunger 154. The linear position sensors 200, 300, 400 of the second sensor 160 convert the position or linear displacement of the second plunger 154 from a reference (e.g., a zero or null position) into a proportional electrical signal. The signals generated by the linear position sensors 200 , 300 , 400 are indicative of the bore dimension BD of the bore at predetermined positions of the plurality of second contact elements 142 , 144 along the central longitudinal axis of the bore .

[0065] 1-4 generally, and 6 and 7 specifically, in one example, first sensor 130 includes or consists of a linear potentiometer 202. The use of linear potentiometer 202 as first sensor 130 provides a compact, simple, and economical means for measuring the position or displacement of first plunger 124 to measure bore dimension BD of bore 42.

[0066] 6 and 7, in one example, linear potentiometer 202 includes a resistive element 204 connected to one of housing 100 and first plunger 124. Linear potentiometer 202 also includes a wiper 206 operatively engaged with (e.g., in contact with) resistive element 204. Wiper 206 is connected to the other of housing 100 and first plunger 124.

[0067] In the present disclosure, when one of the resistive element 204 or the wiper 206 is connected to the housing 100, this member may be referred to as a fixed member, and when one of the resistive element 204 or the wiper 206 is connected to the first plunger 124, this member may be referred to as a moving member. In response to the radial inward movement of the plurality of first contact elements 112, 114, the first plunger 124 moves in a direction parallel to the first plunger axis A. P1 When the movable member moves linearly relative to the housing 100 along the resistive element 204, the movable member moves relative to the fixed member. The relative movement of the wiper 206 along the resistive element 204 generates an electric potential (voltage). The linear potentiometer 202 measures the voltage and generates an output signal ratiometric to the voltage. The output signal generated by the linear potentiometer 202 is indicates the hole dimension BD of the hole 42 at predetermined positions of the plurality of first contact elements 112, 114 along the longitudinal central axis of the hole 42.

[0068] 1-4 generally, and 6 and 7 specifically, in one example, second sensor 160 includes a linear potentiometer 202. Using linear potentiometer 202 as second sensor 160 can provide a compact, simple, and economical means for measuring the position or displacement of second plunger 154 to measure bore dimension BD of bore 42.

[0069] 6 and 7, in one example, the linear potentiometer 202 includes a resistive element 204 connected to one of the housing 100 and the second plunger 154. The linear potentiometer 202 also includes a wiper 206 operatively engaged with (e.g., in contact with) the resistive element 204. The wiper 206 is connected to the other of the housing 100 and the second plunger 154. In response to radially inward movement of the second contact elements 142, 144, the second plunger 154 moves relative to the second plunger axis A. P2 , relative to the housing 100, moves the moving member relative to the fixed member. The relative movement of the wiper 206 along the resistive element 204 generates an electric potential (voltage). The linear potentiometer 202 measures the voltage and generates an output signal ratiometric to the voltage. The output signal generated by the linear potentiometer 202 indicates the bore dimension BD of the bore 42 at a predetermined position of the plurality of second contact elements 142, 144 along the longitudinal central axis of the bore 42.

[0070] 1-4 generally, and 8-10 specifically, in one example, first sensor 130 includes a linear variable differential transformer 302. Using a linear variable differential transformer 302 as first sensor 130 provides a robust, versatile, and reliable sensor for measuring the position or displacement of first plunger 124 to measure bore dimension BD of bore 42. A highly reliable means can be provided.

[0071] As shown in FIGS. 8-10, in one example, the linear variable differential transformer 302 includes a first secondary coil 304 and a second secondary coil 306, both of which are within the housing 100. The linear variable differential transformer 302 further includes a primary coil 308, which is disposed within the housing 100 and carried by the first plunger 124. The primary coil 308 is oriented along the first plunger axis A. P1 , between the first secondary coil 304 and the second secondary coil 306.

[0072] When the primary coil 308 is driven by an alternating current, a voltage is induced in the first secondary coil 304 and the second secondary coil 306. The first plunger 124 is rotated along the first plunger axis A. P1 , the inductive link between the primary coil 308, the first secondary coil 304, and the second secondary coil 306 changes, causing a change in the induced voltage. The linear variable differential transformer 302 measures the differential voltage and generates an output signal. The output signal generated by the linear variable differential transformer 302 indicates the bore dimension BD of the bore 42 at a predetermined position of the plurality of first contact elements 112, 114 along the longitudinal central axis of the bore 42.

[0073] 8-10, in one example, first plunger 124 includes a ferromagnetic material. In one example, first plunger 124 is made of a ferromagnetic material (e.g., an iron-nickel alloy). In another example, the ferromagnetic material is bonded to an outer surface of first plunger 124.

[0074] 1-4 generally, and 8-10 specifically, in one example, second sensor 160 includes a linear variable differential transformer 302. Using a linear variable differential transformer 302 as second sensor 160 can provide a robust, versatile, and reliable means for measuring the position or displacement of second plunger 154 to measure bore dimension BD of bore 42.

[0075] 8-10, in one example, the linear variable differential transformer 302 includes a first secondary coil 304 and a second secondary coil 306, both of which are disposed within the housing 100 and carried by the second plunger 154. The linear variable differential transformer 302 further includes a primary coil 308, which is disposed within the housing 100 and carried by the second plunger 154. The primary coil 308 is oriented along the axis A of the second plunger. P2 The second plunger 154 is disposed along the second plunger axis A between the first secondary coil 304 and the second secondary coil 306. P2 , the inductive link between the primary coil 308, the first secondary coil 304, and the second secondary coil 306 changes, causing a change in the induced voltage. The linear variable differential transformer 302 measures the differential voltage and generates an output signal. The output signal generated by the linear variable differential transformer 302 indicates the bore dimension BD of the bore 42 at a predetermined position of the plurality of second contact elements 142, 144 along the longitudinal central axis of the bore 42.

[0076] 1-4 generally, and 11 and 12 specifically, in one example, the first sensor 130 includes a linear encoder 402. Using the linear encoder 402 as the first sensor 130 can provide a reliable and accurate means for measuring the position or displacement of the first plunger 124 to measure the bore dimension BD of the bore 42.

[0077] 1-4 generally, and 11 and 12 specifically, in one example, second sensor 160 includes a linear encoder 402. Using linear encoder 402 as second sensor 160 can provide a reliable and accurate means for measuring the position or displacement of second plunger 154 to measure bore dimension BD of bore 42.

[0078] 1-4 generally, and 11 and 12 specifically, in one example, the first sensor 130 includes an optical linear encoder 404. The optical linear encoder 404 includes a scale 406 on the first plunger 124. The optical linear encoder 404 also includes a light source 408 that is disposed in the interior space 102 of the housing 100 to illuminate at least a portion of the scale 406. The optical linear encoder 404 further includes a light detector 410 that is disposed in the interior space 102 of the housing 100 to receive light reflected from the scale 406.

[0079] The first plunger 124 is aligned with the first plunger axis A. P1 As the optical linear encoder 404 moves along the scale 406, it uses a light detector 410 to read linear graduations formed on the scale 406 by light reflected from the scale 406. The optical linear encoder 404 measures the displacement of the first plunger 124 based on the difference in the graduations and generates an output signal. The output signal generated by the optical linear encoder 404 indicates the bore dimension BD of the bore 42 at a predetermined position of the plurality of first contact elements 112, 114 along the longitudinal central axis of the bore 42.

[0080] In one example, the second sensor 160 includes an optical linear encoder 404. The optical linear encoder 404 includes a scale 406 on the second plunger 154. The optical linear encoder 404 also includes a light source 408 that is disposed in the interior space 102 of the housing 100 to illuminate at least a portion of the scale 406. The optical linear encoder 404 further includes a light detector 410 that is disposed in the interior space 102 of the housing 100 to receive light reflected from the scale 406.

[0081] The second plunger 154 is aligned with the second plunger axis A. P2As the second plunger 154 moves along the axis 406, the optical linear encoder 404 uses the light detector 410 to read the linear graduations formed on the scale 406 by the light reflected from the scale 406. The optical linear encoder 404 measures the displacement of the second plunger 154 based on the difference in the graduations and generates an output signal. The output signal generated by the optical linear encoder 404 indicates the bore dimension BD of the bore 42 at a predetermined position of the plurality of second contact elements 142, 144 along the longitudinal central axis of the bore 42.

[0082] 11 and 12, in one example, light source 408 includes an optical fiber 412. In other examples, light source 408 is one of a laser, a hollow tube borescope, a backlit encoder with a light sensor, or the like.

[0083] 1-4 generally, and 13-17 specifically, in one example, at least one of the first sensor 130 and the second sensor 160 includes a strain gauge 500. In one example, the first sensor 130 and the second sensor 160 both include a strain gauge 500. The use of a strain gauge 500 as at least one of the first sensor 130 and the second sensor 160 can provide a compact, accurate, and economical means for measuring the external force applied to each of the plurality of first contact elements 112, 114 and / or the plurality of second contact elements 142, 144 to measure the hole dimension BD of the hole 42.

[0084] 2-4 generally, and specifically, with reference to FIGS. 13 and 15, in one example, each first contact element 112, 114 of the plurality of first contact elements 112, 114 is connected to the housing 100 by a corresponding retaining portion 116, 118 of the plurality of retaining portions 116, 118. As shown in FIGS. 13 and 15, in one example, the first sensor 130 includes at least one strain gauge 500 connected to the retaining portion 116, 118 of the plurality of retaining portions 116, 118. Using the strain gauge 500 as the first sensor 130 This provides a compact, accurate and economical means for measuring the hole dimension BD of the hole 42 by measuring the strain at a corresponding one of the plurality of holding portions 116, 118.

[0085] While Figure 15 shows an example of a first sensor 130 including a strain gauge 500 connected to a first holding portion 116, Figure 15 also shows an example of a first sensor 130 including a strain gauge 500 connected to a first holding portion 118.

[0086] The radial inward movement of the plurality of first contact elements 112, 114 applies a force to a corresponding one of the plurality of retaining portions 116, 118. The strain gauges 500 convert the force (e.g., tension) applied to the corresponding retaining portion 116, 118 into a change in electrical resistance. The strain gauges 500 measure the difference in resistance that changes with the applied force and generate an output signal. The output signal generated by the strain gauges 500 indicates the bore dimension BD of the bore 42 at a predetermined position of the plurality of first contact elements 112, 114 along the longitudinal central axis of the bore 42.

[0087] 2-4 generally, and 14 and 15 specifically, in one example, each of the second contact elements 142, 144 is connected to the housing 100 by a corresponding retaining portion 146, 148 of the plurality of retaining portions 146, 148. As shown in FIGS. 14 and 15, in one example, the second sensor 160 includes at least one strain gauge 500 connected to a retaining portion 146, 148 of the plurality of retaining portions 146, 148. The use of the strain gauge 500 as the second sensor 160 can provide a compact, accurate, and economical means for measuring the strain at the corresponding retaining portion 146, 148 of the plurality of retaining portions 146, 148 to measure the hole dimension BD of the hole 42.

[0088] FIG. 15 shows an example of a first sensor 130 including a strain gauge 500 connected to the first holding portion 116, but also shows an example of a second sensor 160 including a strain gauge 500 connected to the second holding portion 146, and an example of a second sensor 160 including a strain gauge 500 connected to the second holding portion 148.

[0089] 1-4 generally, and 16 and 17 specifically, in one example, the first sensor 130 includes a strain gauge 500 connected to two of the plurality of first contact elements 112, 114. The use of the strain gauge 500 as the first sensor 130 can provide a compact, accurate, and economical means for measuring the relative displacement of the two first contact elements 112, 114 to measure the hole dimension BD of the hole 42.

[0090] The radial inward movement of the two first contact elements 112, 114 applies a force to the strain gauge 500. The strain gauge 500 converts the force (e.g., a compressive force) into a change in electrical resistance. The strain gauge 500 measures the difference in resistance that changes with the applied force and generates an output signal. The output signal generated by the strain gauge 500 indicates the bore dimension BD of the bore 42 at a predetermined position of the two first contact elements 112, 114 along the longitudinal central axis of the bore 42.

[0091] 1-4 generally, and 16 and 17 specifically, in one example, the second sensor 160 includes a strain gauge 500 connected to two of the plurality of second contact elements 142, 144. The use of the strain gauge 500 as the second sensor 160 provides a compact, accurate, and economical means for measuring the relative displacement of the two second contact elements 142, 144 to measure the hole dimension BD of the hole 42. It is possible.

[0092] The radial inward movement of the two second contact elements 142, 144 applies a force to the strain gauge 500. The strain gauge 500 converts the force (e.g., a compressive force) into a change in electrical resistance. The strain gauge 500 measures the difference in resistance that changes with the applied force and generates an output signal. The output signal generated by the strain gauge 500 indicates the bore dimension BD of the bore 42 at a predetermined position of the two second contact elements 142, 144 along the longitudinal central axis of the bore 42.

[0093] 1-17, in one particular example, the plug gauge 10 of the present disclosure has an interior space 102 and a longitudinal axis A. H The housing 100 defines a , a pair of first openings 104, 106 that communicate with the interior space 102, and a pair of second openings 108, 110 that communicate with the interior space 102. The pair of second openings 108, 110 are spaced apart from the pair of first openings 104, 106 along the longitudinal axis A. H is displaced a predetermined non-zero distance D along the The lug gauge 10 further has a longitudinal axis A H A first contact element axis A is approximately perpendicular to C1 Located along The plug gauge 10 includes a pair of aligned first contact elements 112, 114. Each first contact element 112, 114 of the pair of first contact elements 112, 114 is received in a corresponding one of the pair of first openings 104, 106. The plug gauge 10 further includes a first plunger 124 that is received in the interior space 102 of the housing 100 and is aligned with the longitudinal axis A of the housing 100. H First plunger axis A aligned with P1 Define the following. The first plunger 124 is aligned with the first plunger axis A P1The plug gauge 10 is movable relative to the housing 100 along a second contact element axis A. The first plunger 124 is biased into engagement with the pair of first contact elements 112, 114. The plug gauge 10 further includes a first sensor 130 that is housed in the interior space 102 of the housing 100 and detects movement of the first plunger 124 relative to the housing 100. The plug gauge 10 is configured to move relative to the housing 100 along a second contact element axis A. C2 and a pair of second contact elements 142, 144 aligned along the second contact element axis A. C2 is the longitudinal axis A H and the first contact element axis A C1 non-zero angle to The second contact elements 142, 144 are disposed at an angle θ to each other. Each of the second contact elements 142, 144 is received in a corresponding one of the second openings 108, 110. The plug gauge 10 further includes a second plunger 154 that is received in the interior space 102 of the housing 100 and is aligned with the longitudinal axis A of the housing 100. H Second plunger axis A aligned with P2 The second plunger 154 defines the first 2 Plunger axis A P2 The second plunger 154 is movable relative to the housing 100 along the second contact elements 142, 144. The second plunger 154 is biased into engagement with the pair of second contact elements 142, 144. The plug gauge 10 further includes a second sensor 160 that detects movement of the second plunger 154 relative to the housing 100.

[0094] 1-4, 6-9, 11-14, and 16, in one or more examples, the second sensor 160 is housed within the interior space 102 of the housing 100. By locating both the first sensor 130 and the second sensor 160 within the interior space 102 of the housing 100, a compact sealed assembly can be provided that can simultaneously perform multiple diameter measurements of holes 42 formed in the structure 40 (FIG. 1).

[0095] 1-4 generally, and 6-17 specifically, in one or more examples, first sensor 130 includes at least one of linear position sensors 200, 300, 400, and strain gauge 500. In one or more examples, second sensor 160 includes at least one of linear position sensors 200, 300, 400, and strain gauge 500.

[0096] Referring to FIG. 1, a system for simultaneously measuring the diameters of a plurality of holes 42 formed in a structure 40 is shown. An example of a stem 8 is disclosed. In one or more examples, the system 8 includes a plug gauge 10. The plug gauge 10 is sized to be received in the bore 42. The system 8 further includes a support 20 connected to the plug gauge 10. In one example, the housing 100, the plurality of first contact elements 112, 114, the first plunger 124, the first sensor 130, the plurality of second contact elements 142, 144, the second plunger 154, and the second sensor 160 form a probe portion 12 of the plug gauge 10. The coupling portion 14 is configured to connect the probe portion 12 to the support 20.

[0097] 1 , in one example, the support 20 includes a robot arm 22. The robot arm 22 is configured to automatically insert a plug gauge 10 (e.g., a probe portion 12) into the hole 42 to perform multiple simultaneous diameter measurements of the hole 42. In one example, the robot arm 22 positions the plug gauge 10 within the hole 42 (at a stationary position along the central longitudinal axis of the hole 42) to perform two simultaneous diameter measurements of the hole dimension BD of the hole 42 at two measurement positions of the plurality of first contact elements 112, 114 and the plurality of second contact elements 142, 144. In one example, the robot arm 22 moves the plug gauge 10 linearly (e.g., along the central longitudinal axis of the hole 42) within the hole 42. As a result, the plurality of first contact elements 112, 114 and the plurality of second contact elements 142, 144 move linearly inside the hole 42, thereby allowing multiple diameter measurements of the hole dimension BD of the hole 42 to be performed simultaneously along the longitudinal central axis of the hole 42. In one example, the robot arm 22 moves the plug gauge 10 to rotate inside the hole 42 (e.g., around the longitudinal central axis of the hole 42) to perform diameter measurements of the hole dimension BD of the hole 42 along the periphery of the hole 42 at two measurement positions along the longitudinal central axis of the hole 42. In one example, the robot arm 22 moves the plug gauge 10 linearly along the central longitudinal axis of the hole 42, and at approximately the same time, rotates the plug gauge 10 about the central longitudinal axis of the hole 42, thereby simultaneously performing multiple diameter measurements of the hole dimension BD of the hole 42 along both the periphery of the hole 42 and the central longitudinal axis of the hole 42.

[0098] In one example, the robot arm 22 includes or functions as the second biasing element 174. For example, one end of the housing 100 is open, and when the plug gauge 10 is connected to the robot arm 22, a portion of the robot arm 22 or a component of the robot arm 22 operably connects to the second plunger 154, thereby biasing the second plunger 154 into engagement with the plurality of second contact elements 142, 144.

[0099] 1 , in one example, system 8 includes a computer system 30. Computer system 30 is in communication with first sensor 130, second sensor 160, and robotic arm 22. Computer system 30 is operable to control robotic arm 22 to automatically position and move plug gauge 10 relative to bore 42. Computer system 30 is also operable to analyze and / or display output signals and measurements generated by first sensor 130 and second sensor 160 indicative of multiple simultaneous diameter measurements of bore dimension BD of bore 42.

[0100] 1-17 generally, and specifically, with reference to FIG. 18, an example method 600 is disclosed for simultaneously taking multiple diameter measurements of holes 42 formed in a structure 40. In one or more examples, the method 600 includes: H A plug gauge 10 having In this disclosure, "provide" in reference to the step of providing a plug gauge 10 (block 610) means to make available or to make available, and does not imply a need to make or supply.

[0101] Referring to FIG. 18 , in one or more examples, the method 600 includes: H The plug gauge 10 is inserted into the hole 42 while being disposed in a first orientation relative to the The method 600 also includes a step (block 620) of measuring the longitudinal axis A H Centered around Rotate the lug gauge 10 to align it with the longitudinal axis A H The plug gauge is arranged in a second orientation relative to the The method 600 further includes the step of withdrawing the plug gauge 10 from the hole 42 (block 640).

[0102] As shown in FIGS. 1-5 , in one example, with the plug gauge 10 positioned in a first orientation within the bore 42, the first contact elements 112, 114 engage with first measurement locations that are radially opposite each other on the inner surface defining the bore 42 to perform a first bore measurement, while the second contact elements 142, 144 engage with second measurement locations that are radially opposite each other on the inner surface defining the bore 42 to perform a second bore measurement. As shown in FIGS. 2 and 3 , in one example, the first and second bore measurements are performed at multiple different positions along the longitudinal central axis of the bore 42, the positions being linearly displaced by a displacement distance D. As shown in FIG. 5 , in one example, the first and second bore measurements are performed at multiple different angular positions about the longitudinal central axis of the bore 42, the positions being displaced by a displacement angle θ.

[0103] After rotating the plug gauge 10 to the second orientation, the first plurality of contact elements 112, 114 engage at radially opposed third measurement locations on the inner surface defining the bore 42 to take the third bore measurement, while the second plurality of contact elements 142, 144 engage at radially opposed fourth measurement locations on the inner surface defining the bore 42 to take the fourth bore measurement. In one example, the third and fourth bore measurements are taken at different locations along the central longitudinal axis of the bore 42, the positions being linearly displaced by a displacement distance D. In one example, the third and fourth bore measurements are taken at different angular positions about the central longitudinal axis of the bore 42, the positions being displaced by a displacement angle θ.

[0104] In one example, the method 600 includes linearly moving the plug gauge 10 within the bore 42 along the central longitudinal axis of the bore 42 while maintaining the plug gauge 10 in one of a first orientation or a second orientation. In one example, the method 600 includes linearly moving the plug gauge 10 within the bore 42 along the central longitudinal axis of the bore 42 while rotating the plug gauge 10 from the first orientation to the second orientation.

[0105] 1-17 generally, and FIG. 18 specifically, in one or more examples, the steps of inserting, rotating, and extracting according to method 600 (blocks 620, 630, and 640) are performed by a robotic arm 22 controlled by a computer system 30.

[0106] In other instances, the steps of inserting, rotating, and withdrawing (blocks 620, 630, and 640) are performed manually, for example, by a human operator.

[0107] Referring to FIG. 1 , in accordance with one or more examples of plug gauge 10, system 8, and method 600, computer system 30 includes a bus or other communication mechanism for communicating information and a processor connected to the bus for processing information. Computer system 30 also includes memory, such as random access memory (RAM) or other dynamic storage device, connected to the bus for storing instructions executed by the processor. Memory may also be used to store intermediate information during execution of instructions executed by the processor. Memory may include, for example, flash memory. Memory may also include read-only memory (ROM) or other static storage device connected to the bus for storing static information and instructions for the processor. For example, storage devices such as magnetic or optical disks may be provided and coupled to the bus for storing information and instructions. Computer system 30 also includes a display for displaying information to a computer user and an input device for communicating information and command selections to the processor.

[0108] The computer system 30 is configured to perform at least some of the operations described herein. In accordance with some aspects of the disclosed embodiments, a processor executes one or more sequences of one or more instructions stored in memory, which in turn causes the computer system 30 to produce results. Such instructions may be loaded into memory from another computer-readable medium, such as a storage device. Execution of the sequences of instructions stored in memory causes the processor to perform the operational steps or processes described herein. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement embodiments of the present disclosure. Thus, implementation of embodiments of the present disclosure is not limited to any specific combination of hardwired circuitry and software. As used herein, the term "computer-readable medium" refers to any medium that participates in providing instructions to a processor for execution. Such media may take various forms, including, but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, storage devices such as optical and magnetic disks. Volatile media include, for example, dynamic memory. Transmission media include wires forming a bus, such as coaxial cables, copper wire, and fiber optics.

[0109] Embodiments of the plug gauge 10, system 8, and method 600 of the present disclosure can be used in a variety of potential applications, particularly in transportation applications such as aerospace. Referring now to Figures 19 and 20, embodiments of the plug gauge 10, system 8, and method 600 can be used in connection with an aircraft manufacturing and service method 1000 as shown in the flow diagram of Figure 19, and in an aircraft 1002 as shown in Figure 20. An aircraft application may include using the plug gauge 10, system 8, and / or method 600 of the present disclosure to simultaneously measure the diameter of multiple holes formed in structures or other components used in the manufacture of the aircraft.

[0110] 20 is an illustration of an example aircraft 1002. The aircraft 1002 includes an airframe 1018, a number of high-level systems 1020, and an interior 1022. Examples of the high-level systems 1020 include one or more of a propulsion system 1024, an electrical system 1026, a hydraulic system 1028, and an environmental system 1030. In other examples, the aircraft 1002 may include any number of other types of systems.

[0111] 20 is an example of an aircraft that includes one or more structures or components having any number of holes used for fastening or other purposes that may be measured using the plug gauge 10, system 8, and / or method 600 of the present disclosure. In one example, the structure 40 (FIG. 1) is a component of the aircraft 1002 or a component of a larger assembly of the aircraft 1002. In one example, the structure 40 forms part of the airframe 1018 of the aircraft 1002, such as a fuselage, wing, vertical stabilizer, horizontal stabilizer, other structure of the aircraft 1002, such as a skin panel, stringer, wing spars, ribs, wing box, stiffener, or part of the interior 1022, such as an interior panel.

[0112] As shown in Figure 19, pre-production steps in method 1000 may include specification and design of aircraft 1002 (block 1004) and material procurement (block 1006). During production of aircraft 1002, component and subassembly manufacturing (block 1008) and system integration (block 1010) of aircraft 1002 occur. Aircraft 1002 then undergoes certification and delivery (block 1012) and is placed into service (block 1014). Embodiments of the plug gauge 10, system 8, and method 600 may form part of component and subassembly manufacturing (block 1008) and / or system integration (block 1010). Routine maintenance and service (block 1016) may include modification, reconfiguration, retrofitting, etc. of one or more systems of the aircraft 1002.

[0113] 19 may be performed by a system integrator, a third party, and / or an operator (e.g., a customer). Note that a system integrator may include, but is not limited to, an aircraft manufacturer and any number of subcontractors of major systems. A third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers. An operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0114] Examples of the plug gauge 10, system 8, and method 600 shown or described herein can be used during one or more of the stages of the manufacturing and service method 1000 shown in the flow diagram of FIG. 19 . For example, a part or subassembly, such as a part including a structure 40 with any number of holes 42, corresponding to part and subassembly manufacturing (block 1008) can be fabricated or manufactured similar to a part or subassembly manufactured during the in-service life (block 1014) of the aircraft 1002 ( FIG. 20 ). Also, one or more examples of the plug gauge 10, system 8, and method 600 described herein can be utilized during the production phase (blocks 1010 and 1012). Similarly, one or more examples of the plug gauge 10, system 8, and method 600 described herein can be utilized, for example, but not by way of limitation, during the in-service life (block 1014) of the aircraft 1002, as well as during the maintenance and service phase (block 1016).

[0115] Although the aerospace industry has been used as an example, the examples and principles disclosed herein are applicable to the automotive, space, construction, and design and manufacturing industries. Thus, the examples and principles disclosed herein are applicable to other vehicle structures (e.g., land vehicles, watercraft, spacecraft, etc.) and stand-alone structures in addition to aircraft. It is Noh.

[0116] As used herein, a system that is "configured to" perform a particular function A system, device, structure, article, element, component, or hardware "Configured" refers to something that can perform a particular function without requiring any modification, and not something that could perform the particular function with some modification. That is, a system, device, structure, article, element, component, or hardware that is "configured" to perform a particular function is something that is specifically selected, made, implemented, utilized, programmed, and / or designed to perform that particular function. As used herein, "configured" refers to a characteristic that a system, device, structure, article, element, component, or hardware already possesses, which characteristic enables the system, device, structure, article, element, component, or hardware to perform the particular function without requiring any modification. In this disclosure, a system, device, structure, article, element, component, or hardware that is "configured" to perform a particular function may also or instead be described as being "adapted to" and / or "operative to" perform that function.

[0117] As used herein, unless otherwise indicated, the terms "first," "second," and the like are used merely as labels and do not impose any order, position, or hierarchical requirement on the elements referred to by these terms. Also, for example, a reference to a "second" element may refer to a lower ordinal element (e.g., the "first" element) and / or a higher ordinal element (e.g., the "second" element). It does not require or exclude the presence of a number of elements (eg, a "third" element).

[0118] In this disclosure, the terms "coupled," "coupling," and similar terms are used. The term refers to two or more elements that are joined, coupled, fastened, connected, in communication, or otherwise associated (e.g., mechanically, electrically, fluidly, optically, electromagnetically) with one another. In various examples, multiple elements may be directly or indirectly associated. For example, element A may be directly associated with element B. Also, for example, element A may be indirectly associated with element B, e.g., through another element C. It should be noted that not all relationships between the various elements of this disclosure are shown. Thus, connections other than those shown may exist.

[0119] As used herein, the phrase "at least one," when used in conjunction with a list of elements, means that one or more of the listed elements may be used in various combinations, or that only one of the listed elements may be required. For example, "at least one of elements A, B, and C" may include, but is not limited to, element A, or element A and element B. This example may also include elements A, B, and C, or element B and element C. In other examples, "at least one" may mean, for example, but not limited to, a combination of two elements A, one element B, and ten elements C, a combination of four elements B, and seven elements C, or any other suitable combination.

[0120] As used herein, terms such as "about," "approximately," and "generally" refer to a state that is close to, but not exactly the same as, a described state, and that is capable of performing a desired function or achieving a desired result. For example, terms such as "about," "approximately," and "generally" refer to a state that is within a predetermined acceptable tolerance or precision. For example, terms such as "about," "approximately," and "generally" refer to a state that is within 10% of the described state. However, terms such as "about," "approximately," and "generally" do not exclude a state that is exactly the same as the described state. As used herein, the term "substantially" refers to a state that is the same as the described state to the extent that it can be considered accurate. For example, the term "substantially" includes a state that is exactly the same as the described state, or a state that is within a predetermined acceptable range of difference, such as within ±5%, ±2%, or ±1%.

[0121] Unless otherwise specified, the schematic diagrams of the examples shown in Figures 1-17 referenced above are not intended to imply architectural limitations with respect to the illustrated examples. Rather, one exemplary structure is shown, but it should be understood that this structure may be modified as appropriate. Accordingly, modifications, additions, and / or deletions may be made to the illustrated structure. Furthermore, those skilled in the art will understand that not all elements described and illustrated herein need be included in every example, and not all elements described herein are necessarily shown in every illustrated example.

[0122] The blocks in Figures 18 and 19 referenced above may represent processes, steps, and / or portions thereof, and lines connecting various blocks do not imply a particular order or dependency of the processes or portions thereof. Where blocks are shown with dashed lines, these represent alternative processes and / or portions thereof. Where dashed lines connecting various blocks, these represent alternative dependencies of the processes or portions thereof. It should be noted that not all dependencies between the various disclosed processes are shown. Figures 18 and 19 and the accompanying disclosure describing the steps in the methods of the present disclosure described herein do not necessarily dictate the order in which these steps are performed. Rather, while one exemplary order is shown, it should be understood that the order of these steps can be changed as appropriate. Thus, these Steps may be modified, added, and / or deleted, and some of the steps may be performed in a different order or simultaneously. Moreover, one skilled in the art will recognize that not all of the steps described need be performed.

[0123] Furthermore, the present disclosure includes examples according to the following appendices.

[0124] Clause 1. A housing defining an interior space and a longitudinal axis, the housing including a plurality of first openings communicating with the interior space and a plurality of second openings communicating with the interior space; a plurality of first contact elements, each at least partially received in a corresponding one of the plurality of first openings in the housing; a first plunger received in the interior space of the housing, defining a first plunger axis aligned with the longitudinal axis of the housing, and movable relative to the housing along the first plunger axis, the first plunger being biased to engage the plurality of first contact elements and urging the plurality of first contact elements radially outward through the plurality of first openings; a first sensor that detects movement of the first plunger relative to the housing; a plurality of second contact elements, each at least partially received in a corresponding one of the plurality of second openings in the housing; a second plunger received in the interior space of the housing, defining a second plunger axis aligned with the longitudinal axis of the housing, and movable relative to the housing along the second plunger axis, the second plunger being biased to engage the plurality of second contact elements and urging the plurality of second contact elements radially outward through the plurality of second openings; a second sensor that detects movement of the second plunger relative to the housing.

[0125] Clause 2. The plug gauge of Clause 1, wherein the plurality of second openings are displaced from the plurality of first openings by a predetermined non-zero distance along the longitudinal axis.

[0126] Appendix 3. The plug gauge of Appendix 1 or 2, wherein the plurality of second openings are displaced by a non-zero angle θ about the longitudinal axis relative to the plurality of first openings.

[0127] Clause 4. The plug gauge of Clause 3, wherein the non-zero angle is approximately 90 degrees.

[0128] Appendix 5. The plug gauge according to any one of appendices 1 to 4, wherein the housing is generally tubular.

[0129] Appendix 6. A plug gauge described in any one of Appendixes 1 to 5, wherein the housing defines an outer surface, and a portion of the plurality of first contact elements and a portion of the plurality of second contact elements protrude radially outward from the outer surface.

[0130] Clause 7. The plug gauge of clause 6, wherein the outer surface is substantially cylindrical.

[0131] Appendix 8. A plug gauge according to any one of Appendixes 1 to 7, wherein the plurality of first contact elements consist of two first contact elements aligned along a first contact element axis that is substantially perpendicular to the longitudinal axis.

[0132] Appendix 9. The plug gauge of Appendix 8, wherein the plurality of second contact elements comprises two second contact elements aligned along a second contact element axis that is substantially perpendicular to the longitudinal axis, and the second contact element axis is arranged at a non-zero angle with respect to the first contact element axis.

[0133] Clause 10. The plug gauge of clause 9, wherein the non-zero angle is approximately 90 degrees.

[0134] Appendix 11. The plug gauge according to any one of appendices 1 to 10, wherein each of the plurality of first contact elements is substantially spherical.

[0135] Clause 12. The plug gauge of clause 11, wherein each of the plurality of second contact elements is substantially spherical.

[0136] Appendix 13: The plug gauge according to any one of Appendixes 1 to 12, wherein each of the plurality of first contact elements and each of the plurality of second contact elements are connected to the housing by a retaining portion.

[0137] Appendix 14. The plug gauge of any one of Appendixes 1 to 13, further comprising a first biasing element arranged to bias the first plunger into engagement with the plurality of first contact elements.

[0138] Clause 15. The plug gauge of clause 14, wherein the first biasing element includes a spring.

[0139] Clause 16. The plug gauge of clause 14 or clause 15, further comprising a second biasing element positioned to bias the second plunger into engagement with the plurality of second contact elements.

[0140] Appendix 17. A plug gauge according to any one of Appendixes 14 to 16, further comprising a setscrew threadedly engaging with the housing, the first biasing element being disposed between the setscrew and the first plunger.

[0141] Appendix 18. A plug gauge according to any one of Appendixes 1 to 17, wherein the first plunger includes a head portion that engages with the plurality of first contact elements, and the head portion includes an inclined surface.

[0142] Appendix 19. A plug gauge according to any one of Appendixes 1 to 18, further comprising a coupling portion connected to a probe portion of the plug gauge, wherein the housing, the plurality of first contact elements, the first plunger, the first sensor, the plurality of second contact elements, the second plunger, and the second sensor are included in the probe portion.

[0143] Supplementary Note 20: The plug gauge according to any one of Supplementary Notes 1 to 19, wherein at least one of the first sensor and the second sensor is disposed in the internal space of the housing.

[0144] Appendix 21. A plug gauge according to any one of appendices 1 to 19, wherein the first sensor and the second sensor are both disposed in the internal space of the housing.

[0145] Appendix 22. The plug gauge of any one of Appendixes 1 to 21, wherein at least one of the first sensor and the second sensor includes a linear position sensor.

[0146] Appendix 23. The plug gauge of any one of Appendixes 1 to 21, wherein the first sensor and the second sensor both comprise linear position sensors.

[0147] Appendix 24. The plug gauge of any one of Appendixes 1 to 21, wherein the first sensor includes a linear potentiometer.

[0148] Addendum 25. The linear potentiometer a resistive element connected to one of the housing and the first plunger; 25. The plug gauge of claim 24, including a wiper operably engaged with the resistance element, the wiper connected to the other of the housing and the first plunger.

[0149] Clause 26. The plug gauge of clause 24 or 25, wherein the second sensor includes a linear potentiometer.

[0150] Appendix 27. The plug gauge of any one of Appendixes 1 to 21, wherein the first sensor includes a linear variable differential transformer.

[0151] Addendum 28. The linear variable differential transformer a first secondary coil, a second secondary coil, and a primary coil; the first secondary coil and the second secondary coil are both disposed within the housing and carried by the first plunger; 28. The plug gauge of claim 27, wherein the primary coil is disposed within the housing, carried by the first plunger, and positioned along the first plunger axis between the first secondary coil and the second secondary coil.

[0152] Clause 29. The plug gauge of clause 28, wherein the first plunger comprises a ferromagnetic material.

[0153] Appendix 30. The plug gauge according to any one of Appendixes 27 to 29, wherein the second sensor includes a linear variable differential transformer.

[0154] Supplementary Note 31. The plug gauge according to any one of Supplementary Notes 1 to 21, wherein the first sensor includes a linear encoder.

[0155] Clause 32. The plug gauge of clause 31, wherein the second sensor includes a linear encoder.

[0156] Addendum 33. The first sensor includes an optical linear encoder, and the optical linear encoder a scale on the first plunger; a light source disposed in the interior space of the housing to illuminate at least a portion of the scale; 22. The plug gauge according to any one of appendixes 1 to 21, further comprising: a light detecting unit disposed in the internal space of the housing to receive light reflected from the scale.

[0157] Clause 34. The plug gauge of clause 33, wherein the light source includes an optical fiber.

[0158] Supplementary Note 35: The plug gauge according to any one of Supplementary Notes 1 to 21, wherein at least one of the first sensor and the second sensor includes a strain gauge.

[0159] Appendix 36. The plug gauge according to any one of appendices 1 to 21, wherein the first sensor and the second sensor both include strain gauges.

[0160] Appendix 37. A plug gauge as described in any one of Appendixes 1 to 21, further comprising a plurality of retaining portions, each of the plurality of first contact elements being connected to the housing by a corresponding one of the plurality of retaining portions.

[0161] Appendix 38. The plug gauge of Appendix 37, wherein the first sensor includes at least one strain gauge connected to one of the plurality of retaining portions.

[0162] Appendix 39. A plug gauge according to any one of Appendixes 1 to 21, wherein the first sensor includes a strain gauge connected to two first contact elements of the plurality of first contact elements.

[0163] Clause 40. A housing defining an interior space and a longitudinal axis, the housing including a first pair of openings communicating with the interior space and a second pair of openings communicating with the interior space, the second pair of openings being displaced a predetermined non-zero distance along the longitudinal axis from the first pair of openings; a pair of first contact elements aligned along a first contact element axis generally perpendicular to the longitudinal axis, each first contact element being received in a corresponding one of the pair of first openings; a first plunger received in the interior space of the housing, defining a first plunger axis aligned with the longitudinal axis of the housing, and movable relative to the housing along the first plunger axis, the first plunger being biased into engagement with the pair of first contact elements; a first sensor accommodated in the interior space of the housing and configured to detect movement of the first plunger relative to the housing; a pair of second contact elements aligned along second contact element axes generally perpendicular to the longitudinal axis and disposed at a non-zero angle with respect to the first contact element axis, each second contact element being received in a corresponding one of the pair of second openings; a second plunger received in the interior space of the housing, defining a second plunger axis aligned with the longitudinal axis of the housing, and movable relative to the housing along the second plunger axis, the second plunger being biased into engagement with the pair of second contact elements; a second sensor that detects movement of the second plunger relative to the housing.

[0164] Appendix 41. The plug gauge of Appendix 40, wherein the second sensor is housed in the interior space of the housing.

[0165] Clause 42. The plug gauge according to clause 40 or 41, wherein the first sensor includes at least one of a linear position sensor and a strain gauge.

[0166] Clause 43. The plug gauge of clause 42, wherein the second sensor includes at least one of a linear position sensor and a strain gauge.

[0167] Appendix 44. A system for simultaneously measuring the diameters of a plurality of holes formed in a structure, the plug gauge of claim 1 sized to be received in the hole; a support connected to the plug gauge.

[0168] Clause 45. The system of clause 44, wherein the support comprises a robotic arm.

[0169] Clause 46. The system of clause 45, further comprising a computer system in communication with the first sensor, the second sensor, and the robotic arm.

[0170] Appendix 47. A method for simultaneously measuring the diameters of a plurality of holes formed in a structure, inserting the plug gauge of claim 1 into the bore with the plug gauge disposed at a first orientation relative to the longitudinal axis; rotating the plug gauge about the longitudinal axis to position the plug gauge in a second orientation relative to the longitudinal axis; and withdrawing the plug gauge from the hole.

[0171] Addendum 48. The method of Addendum 47, wherein the inserting, rotating, and extracting are performed by a robotic arm controlled by a computer system.

[0172] Furthermore, the use of phrases referring to features and advantages, or phrases similar to each other, in this specification does not imply that all features and advantages that can be realized in the embodiments disclosed herein should or are included in any single embodiment. Rather, phrases referring to features and advantages mean that the particular feature, advantage, or characteristic described in connection with one embodiment is included in at least one example. Thus, the use of phrases referring to features and advantages in this specification, and phrases similar to each other, may or may not refer to the same embodiment.

[0173] Features, advantages, and characteristics described in one embodiment may be combined in any suitable manner in one or more other embodiments. Those skilled in the art will appreciate that the embodiments described herein may be practiced even without one or more of the specific features or advantages of a particular embodiment. Also, some embodiments may include additional features and advantages that may not be present in all embodiments. Furthermore, while various examples of plug gauge 10, system 8, and method 600 have been shown and described, modifications will occur to those skilled in the art upon reading this specification. The present application includes such modifications and is limited only by the scope of the claims.

Claims

1. The interior space and the longitudinal axis (A H a housing defining a space communicating with said interior space; a housing including a plurality of first openings communicating with the interior space and a plurality of second openings communicating with the interior space; a plurality of first contact elements, each at least partially received in a corresponding one of the plurality of first openings in the housing; A first plunger axis (A) is received in the interior space of the housing and aligned with the longitudinal axis of the housing. P1 a first plunger defining a first contact element and movable relative to the housing along the first plunger axis, the first plunger being biased to engage the first contact elements and urging the first contact elements radially outward through the first openings; a first sensor that detects movement of the first plunger relative to the housing; a plurality of second contact elements, each at least partially received in a corresponding one of the plurality of second openings in the housing; A second plunger axis (A) is received in the interior space of the housing and aligned with the longitudinal axis of the housing. P2 a second plunger defining a second contact element and movable relative to the housing along the second plunger axis, the second plunger being biased to engage the second contact elements and urging the second contact elements radially outward through the second openings; a second sensor that detects movement of the second plunger relative to the housing.

2. The plurality of second openings are arranged to extend from the plurality of first openings along the longitudinal axis (A H ) along the specified 2. The plug gauge of claim 1, wherein the plug is displaced by a non-zero distance (D) of

3. The plurality of second openings are aligned along the longitudinal axis (A H ) to the plurality of first openings 3. The plug gauge of claim 1, wherein the plug gauge is displaced by a non-zero angle θ relative to the axis of rotation of the plug.

4. The plug gauge according to any one of claims 1 to 3, wherein the housing defines an outer surface, and a portion of the plurality of first contact elements and a portion of the plurality of second contact elements protrude radially outward from the outer surface.

5. The plurality of first contact elements are aligned along the longitudinal axis (A H A first contact element axis (A) substantially perpendicular to the C1 The second contact elements are aligned along a second contact element axis (A ) that is substantially perpendicular to the longitudinal axis. C2 5. The plug gauge of claim 1, wherein the second contact element axis is disposed at a non-zero angle θ relative to the first contact element axis.

6. The plug gauge according to any one of claims 1 to 5, wherein each of the plurality of first contact elements and each of the plurality of second contact elements are connected to the housing by a retaining portion.

7. 7. The plug gauge of claim 1, further comprising a first biasing element arranged to bias the first plunger into engagement with the plurality of first contact elements, a second biasing element arranged to bias the second plunger into engagement with the plurality of second contact elements, and a setscrew threadedly engaged with the housing, the first biasing element being arranged between the setscrew and the first plunger.

8. The plug gauge according to any one of claims 1 to 7, wherein the first plunger includes a head portion that engages with the plurality of first contact elements, the head portion including an inclined surface.

9. 9. The plug gauge of claim 1, further comprising a coupling portion connected to a probe portion of the plug gauge, wherein the housing, the plurality of first contact elements, the first plunger, the first sensor, the plurality of second contact elements, the second plunger, and the second sensor are included in the probe portion.

10. At least one of the first sensor and the second sensor comprises a linear position sensor or a linear potentiometer, the linear potentiometer comprising: a resistive element connected to one of the housing and the first plunger; A plug gauge according to any preceding claim, including a wiper operatively engaged with the resistance element, the wiper being connected to the other of the housing and the first plunger.

11. At least one of the first sensor and the second sensor includes a linear variable differential transformer, the linear variable differential transformer comprising: a first secondary coil, a second secondary coil, and a primary coil; the first secondary coil and the second secondary coil are both disposed within the housing and carried by the first plunger; The primary coil is disposed in the housing, is carried by the first plunger, and is connected to the first plunger shaft (A P1 ) between the first secondary coil and the second secondary coil, The plug gauge according to any one of claims 1 to 9, wherein the first plunger includes a ferromagnetic material.

12. At least one of the first sensor and the second sensor includes a linear encoder or an optical linear encoder, and the optical linear encoder includes: a scale on the first plunger; a light source disposed in the interior space of the housing to illuminate at least a portion of the scale; a light detector disposed in the interior space of the housing to receive light reflected from the scale; The plug gauge according to any one of claims 1 to 9, wherein the light source includes an optical fiber.

13. 10. A plug gauge according to claim 1, further comprising a plurality of retaining portions, each of the plurality of first contact elements being connected to the housing by a corresponding one of the plurality of retaining portions, and at least one of the first sensor and the second sensor including at least one strain gauge connected to one of the plurality of retaining portions.

14. A method for simultaneously measuring the diameters of a plurality of holes formed in a structure, comprising: The plug gauge of claim 1, wherein the longitudinal axis (A H ) arranged in a first orientation relative to inserting the plug gauge into the hole in a state rotating the plug gauge about the longitudinal axis to position the plug gauge in a second orientation relative to the longitudinal axis; and withdrawing the plug gauge from the hole.

15. 15. The method of claim 14, wherein the inserting, rotating, and extracting are performed by a robotic arm controlled by a computer system.

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