Abstract:
A method of measuring an interior diameter of a bore with an expandible gauge having relatively movable first and second components and placing an adhesive on at least one of the first and the second components for adhesively bonding the first and the second components to one another. Inserting the expandible gauge into a tool hole in a bore bar and sliding the bore bar into the bore so that the tool hole is located within the bore. Allowing the expandible gauge to expand to a diameter of a bore to be measured and adhesively bond the first and the second components to one another. Removing the expandable gauge and determining the diameter of the bore by measuring a length of the expandible gauge.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a bore gauge for measuring the interior diameter of a bore, for example, during machining of a bore in large equipment by means of a portable boring machine, and, in particular, for measuring a bore with minimum clearance between the walls of the bore and a boring bar. 
       BACKGROUND OF THE INVENTION 
       [0002]    Heavy equipment and machinery frequently require repair and it is generally preferable that such repair be done in the field rather than transporting the machinery or equipment to a suitable repair facility as this reduces the associated time and costs required for repair. One of the most commonly required repairs for large machinery or equipment is the repair of a bore, that is, a circular opening that supports an axle or shaft, for example, and this circular opening becomes damaged or excessively worn due to a variety of different reasons or causes. Alternatively, a bore can be bored out to a slightly larger for a variety of different reasons. 
         [0003]    The repair of a damaged or worn bore typically involves rebuilding the interior surface of the bore by the deposition of a metal, typically by a welding or a flame deposition process, and the subsequent boring and machining of the rebuilt or refabricated bore to the a precisely required diameter. These operations are typically performed in the field by means of a portable boring machine which has a boring bar that is inserted into the bore. The boring bar is typically supported on bearings on each side of the bore and may be fitted with a variety of tools for repairing the bore, such as a welding head and a variety of cutting or machining tools. 
         [0004]    This arrangement, that is, of a boring bar bearing one or more bore repair tools and supported at each end of the bore by bearings, provides the radial support and rigidity for the tools that is necessary for the accurate reconstruction of a bore, but also presents other problems and shortcomings. For example, and in particular, the accurate reconstruction of a bore requires the periodic measurement of the interior diameter of the bore at various points in the reconstruction process to ensure an accurate rebuilt or refabrication of the bore. 
         [0005]    While it is obviously possible to insert any of a number of interior bore measuring devices into a bore, such as interior calipers or an expandible micrometer, it is preferable that the measurements be made without removing the bore bar from the bore as this essentially requires disassembly, or at least dismounting, of a portion of the boring machine, such as the bearings. This, in turn, significantly increases the time required to complete the repair procedure and the probability that errors and inaccuracies will be introduced when reassembling and remounting the bore bar and bearings and/or readjusting the bore bar tool. 
         [0006]    The most accurate and cost effective of the previously available bore measurement devices are, therefore, those which are inserted into a tool hole extending across a diameter of the bore bar and which include a mechanism by which the length of a measuring device can be expanded into contact with the interior surface of the bore at a pair of diametrically opposed points. The diameter of the bore can then be determined by withdrawing the bore bar sufficiently from the bore for the measuring device to be removed from the tool hole and measuring the expanded device or reading the diameter from a measurement scale on the device. 
         [0007]    However, this type of device is not free of problems because it is necessary to insert an adjustment tool into the bore to expand and lock the measuring device. This requires the adjustment tool to fit between the outside diameter of the bore bar and the inside diameter of the bore, and to be able to operate and function in this space. There is often insufficient space to fit the adjustment tool between the bore bar and the interior of the bore, particularly since it is preferable to use the largest diameter bore bar that will fit into the bore in order to provide the maximum possible radial support and rigidity for the bore bar and tools. This problem may be overcome, for example, by reducing the diameter of the bore bar, but this reduces the radial support and rigidity of the bore bar and tools, thereby increasing the possibility of an error in the diameter or shape of the bore and increasing the time required for the cutting or machining operations. It will also be recognized that this problem cannot be overcome by using a larger diameter bore bar for reconstruction operations and a smaller diameter bore bar for the measurements as this would again require removal of the bore bar and bearings, leading to the same problems as discussed above. 
         [0008]    The present invention provides a solution to these and related problems of the prior art. 
       SUMMARY OF THE INVENTION 
       [0009]    Wherefore, it is an object of the present invention to overcome the above mentioned shortcomings and drawbacks associated with the prior art. 
         [0010]    Another object of the present invention is to provide an inexpensive but reliable device, e.g., an expandible gauge, for accurately measuring the inside diameter of a bore being repaired. 
         [0011]    Yet another object of the present invention is to provide a procedure which avoids disassembling the bore bar to thereby reduce the time required to obtain a measurement of a bore and thus reduce the time required to complete the repair procedure for the bore being repaired. 
         [0012]    The present invention relates to a method of measuring an interior diameter of a bore, the method comprising the steps of: providing an expandible gauge having relatively movable first and second components; placing an adhesive on at least one of the first and the second components such that the adhesive can temporarily bond the first and the second components to one another; inserting the expandible gauge into a tool hole in a bore bar; sliding the bore bar into the bore so that the tool hole and the expandible gauge are located within the bore; allowing the expandible gauge to expand to a diameter of a bore to be measured; allowing the adhesive to bond the first and the second components of the expandible gauge to one another; and removing the expandible gauge and determining the diameter of the bore by measuring a length of the expandible gauge. 
         [0013]    The present invention also relates to a method of measuring an interior diameter of a bore, the method comprising the steps of: placing a predetermined quantity of an adhesive on a first component of an expandible gauge at a location that will overlap with a second component of the expandible gauge when outer ends of the first and the second components of the expandible gauge are moved apart by a distance corresponding to a diameter of a bore to be measured; inserting the expandible gauge into a tool hole in a bore bar; sliding the bore bar into the bore so that the tool hole and the expandible gauge are located within the bore; allowing the expandible gauge to expand so that the outer ends of the first and the second components of the expandible gauge are moved apart by a distance corresponding to a diameter of a bore to be measured; allowing the adhesive to bond the first and the second components of the expandible gauge to one another; sliding the bore bar out of the bore until the expandible gauge can be removed from the tool hole, and determining the diameter of the bore by measuring the distance between the outer ends of the first and the second components of the expandible gauge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0014]    The present invention will now be described by way of example with reference to the accompanying drawings, in which: 
           [0015]      FIG. 1  is a diagrammatic representation of an expandable gauge of a minimum clearance bore gauge; 
           [0016]      FIG. 2  is a diagrammatic representation of the assembly of an expandible gauge into a gauge adapter into a minimum bore gauge and the insertion of the assembled minimum bore gauge expandible into a gauge hole in a bore bar; 
           [0017]      FIGS. 3 and 4  are illustrations showing insertion of the assembled bore bar with the minimum bore gauge into a bore; 
           [0018]      FIG. 5  is a diagrammatic cross section view of the expandible gauge and gauge adapter in a tool hole of a bore bar in a bore when expanded to measure the bore; and 
           [0019]      FIG. 6  is an illustration showing use of an expandible gauge retainer clip to restrain premature expansion of the expandible gauge. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    Referring to  FIGS. 1 and 5 , a minimum clearance bore gauge  10  of the present invention includes an expandible gauge  12  that, in turn, includes a gauge body  14 , a gauge plunger  16  and an internal compression or expansion spring  18 . As illustrated, the gauge body  14  is hollow and receives and contains the expansion spring  18  therein. In addition, a first end  16 A of the gauge plunger  16  is also received by and partially within the first end  14 A of the gauge body  14 . The opposed outer ends  14 B and  16 B of the gauge body  14  and the gauge plunger  16  each terminate, for example, as a rounded tip in which the radii of outer ends  14 B and  16 B of the gauge body  14  and the gauge plunger  16  are both less than the radius of the bore to be measured. This insures that the inner surface of the bore to be measured will be contacted only by a surface of the opposed outer end which lies along a longitudinal centerline of the expandible gauge  12 , thereby avoiding possible measurement errors due to ends  14 B and  16 B bridging a chord of the bore diameter and resulting in a measurement that is possibly less than the full diameter of the bore to be measured. 
         [0021]    Also according to the present invention, the maximum diameters of both the gauge plunger  16  and the expansion spring  18  are less than the inner diameter of the gauge body  14  so that the gauge plunger  16  is allowed to slide freely within and relative to the gauge body  14  and the expansion spring  18  is allowed to compress and decompress within the gauge body  14  during such corresponding sliding movement of the gauge plunger  16 . The exterior diameter of gauge plunger  16  is, however, sufficiently close to the inside diameter of gauge body  14  to prevent excessive side to side movement or axial tilting of the gauge plunger  16  relative to the gauge body  14 , thereby insuring that the gauge body  14  and the gauge body  16  both remain substantially aligned with one another along the longitudinal centerline or axis A of the expandible gauge  12 . 
         [0022]    As will be described further below, the distance or length between the outer end  14 B of the gauge body  14  and the outer end  16 B of the gauge plunger  16  correspond to and represent the interior diameter of the bore to be measured. As a result of this, by alignment of the longitudinal centerline or axis A of the expandible gauge  12 , passing through the gauge body  14  and the gauge plunger  16 , with a diameter of the bore to be measured, errors due to a “bent” scale measurement are normally necessarily prevented. 
         [0023]    Referring next to  FIGS. 2 and 5 , a minimum clearance bore gauge  10  which, as illustrated therein, comprises the expandible gauge  12  and a gauge adapter  20 , is inserted into a tool hole  22  in a bore bar  24 . As shown, the gauge adapter  20  includes a central gauge hole  20 G for receiving, with a close sliding fit, the expandible gauge  12  so that expandible gauge  12  may be slide into gauge adapter  20  but will be retained therein with its longitudinal axis aligned substantially with a longitudinal axis of the gauge hole  20 G. 
         [0024]    Tool hole  22  extends perpendicular to the longitudinal axis of bore bar  24  and the axis of tool hole  22  is coincident with a diameter of bore bar  24 . The outer dimensions of the gauge adapter  20 , which is illustrated as having a generally square cross section but may have a circular or a polygonal cross section, is such that the gauge adapter  20  has a close sliding fit within the tool hole  22 . The central axis of gauge adapter  20  and thus the longitudinal axis of the expandible gauge  12  will thereby be coincident with the central axis of tool hole  22  and will be parallel to the longitudinal axis of the bore to be measured. In this regard, it should be noted that the rotational orientation of the expandible gauge  12 , with respect to the bore to be measured, is typically not a source of error in the measurement of the bore. The dimensions of the expandible gauge  12 , the gauge adapter  20  and the tool hole  22  must, however, be of sufficiently small clearance so that the expandible gauge  12  cannot assume an orientation that is tilted with respect to the longitudinal axis of the bore because such tilting of the expandible gauge  12 , i.e., the expandible gauge  12  does not extend parallel to a diameter of the bore to be measured, could result in an erroneous measurement across a longitudinal diagonal of the bore. 
         [0025]    Referring now to  FIGS. 3 ,  4  and  5  and considering the use of a minimum clearance bore gauge  10 , the gauge body  14 , the gauge plunger  16  and the expansion spring  18  are first assembled into the expandible gauge  12  and a drop of a high strength, fast drying glue or adhesive  26  is placed on the outer surface of gauge plunger  16  at an adhesive location  26 A. As illustrated in  FIG. 5 , the adhesive location  26 A is selected so that the drop of adhesive  26  will be properly positioned to adhesively secure an inwardly facing surface of the gauge body  14  to an outwardly facing surface of the gauge plunger  16 , once the expansion spring  18  expands, so that the overall length of the expandible gauge  12  is equal to the interior diameter of the bore  28  to be measured. This insures that when the expandible gauge  12  is permitted to fully expand to the diameter of the bore to be measured, the drop of adhesive  26  will be located in a region of the overlap sidewalls of the gauge body  14  and the gauge plunger  16  to facilitate temporarily bonding of those two surfaces to one another. The drop of adhesive  26  will thereby be in contact with both the inwardly facing surface of the gauge body  14  and mating the outward facing surface of gauge plunger  16  and, as described below, will temporarily bond the gauge plunger  16  to the gauge body  14 . 
         [0026]    After the drop of adhesive  26  is applied to the adhesive location  26 A, the expandible gauge  12  is then inserted into the central gauge hole  20 G of the gauge adapter  20  and the assembly of the expandible gauge  12  and the gauge adapter  20  is then inserted into the tool hole  22  in the bore bar  24 . Next, the bore bar  24  is moved or slid into the bore  28  of the desired machine or equipment  30  being repaired so that tool hole  22  is locate within the bore being repaired  28 . Once in this position, the expansion spring  18  can then resiliently bias and move the gauge body  14  and the gauge plunger  16 , relative to one another, along the longitudinal axis of the expandible gauge  12  until outer opposed ends  14 B and  16 B of the gauge body  14  and the gauge plunger  16  each contact and abut against an inwardly facing surface of bore being repaired  28 , at diametrically opposed points within the bore. The distance between opposed outer ends  14 B and  16 B of the gauge body  14  and the gauge prove  16  will therefore be equivalent to the interior diameter of the bore being repaired  28 . 
         [0027]    The bore bar  24  carrying the expandible gauge  12  is then maintained in this position for a sufficient duration of time, e.g., between about 5 seconds to about ten minutes and more preferably about  15  seconds to about three 3 minutes, until the drop of adhesive  26  adequately dries, hardens, cures and/or bonds the gauge plunger  16  to the gauge body  14  and securely affixes the spacing of the gauge body  14  relative to the gauge plunger  16  so that the spacing between of the opposed outer ends  14 B and  16 B of the expandible gauge  12  are equal to the interior diameter of bore being repaired  28 . 
         [0028]    Once the drop of adhesive  26  has sufficiently dried, hardened, cured and/or bonded, the bore bar  24  is withdrawn from bore  28  by a distance sufficient to allow the removal of the expandable gauge  12  and the gauge adapter  20  from the tool hole  22 . Following removal of expandible gauge  12 , the operator then measures the length of expandible gauge  12 , i.e., spacing between of the opposed outer ends  14 B and  16 B of the expandible gauge  12 , with a micrometer or some other suitable measuring device, for example, to determine the interior diameter of the bore being repaired  28 . 
         [0029]    Once the measurement is obtained, the expandible gauge  12  may thereafter be properly discarded or preferably, since the expandible gauge  12  is intended to be reusable, the entire expandible gauge  12  is placed or submerged within a bath of a suitable solvent, depending upon the type of adhesive being utilized. The solvent will softer and/or dissolve the cured or harden drop of adhesive  26  so that adhesive is, or can be, removed and thereafter the gauge plunger  16  is again allowed to slide freely within and relative to the gauge body  14  to facilitate reuse of spacing between of the opposed outer ends  14 B and  16 B of the expandible gauge  12 . The presently claimed invention covers both reuse of and disposal of the expandible gauge  12 . 
         [0030]    Finally, it will be noted that in some circumstances it may be difficult or awkward to restrain expandible gauge  12  from expanding while inserting the bore bar  24  into the bore to be repaired  28  to a location where the tool hole  22  is sufficiently located within the bore  28 , such as when the measurement is being taken by a single operator. In such instance, a C-clip  32 , an example of which is illustrated in  FIGS. 2 and 6 , may be slid over the bore bar  24  and the ends of tool hole  22  and engage and sandwich the opposed outer ends  14 B and  16 B of the expandible gauge  12  so as to restrain expandible gauge  12  in a partially compressed state (see  FIG. 6 , for example). As illustrated, the distance between the inwardly facing end surfaces of C-clip  32  is greater than the bore bar  24  but less than the interior diameter of the bore to be repaired  28 . Normally the spacing of the inwardly facing end surfaces of C-clip  32  is typically approximately to the outer diameter of the bore bar  24 . C-clip  32  will thereby restrain expandible gauge  12  in the partially compressed state until the bore bar  24  is slid into the bore to be repaired  28  sufficiently far enough so that the tool hole  22  and the expandible gauge  12  begin to enter the bore to be repaired  28 . At this point, the C-clip  32  may either be removed by the operator or user or the C-clip  32  will simply become disengaged from the expandible gauge  12  and/or the bore bar  24  but abutting against a surface of the machine or the equipment structure  30  surrounding the bore to be repaired  28 , thereby releasing the expandible gauge  12  so that the gauge can thereafter freely expand to match the diameter of the bore to be repaired  28 , as described above. 
         [0031]    It is to be appreciated that for small or larger size bores to be repaired  28 , the overall size and/or dimensions of the gauge body  14 , the gauge plunger  16  and the internal compression or expansion spring  18  will vary. But for all embodiments, the gauge body  14  and the gauge plunger  16  must be freely movable, relative to one another, as described above to provide an accurate measurement of the bore to be measured. The gauge body  14  typically has a length of between about 0.5 inch and about two feet and a diameter or width dimension of between about ⅛ of inch and about 1 inch, the gauge plunger  16  typically has a length of between about 0.25 of an inch and about twenty four inches and a diameter or width dimension of between about 3/32 and about 15/16 on an inches, and the internal compression or expansion spring  18  typically has a length of between about ¼ and about six inches. 
         [0032]    Lastly, the bore gauge  10 , the gauge body  14 , the gauge plunger  16  and the gauge adapter  20  are each typically manufactured from metal, plastic material, a phenolic, or any other machinable or moldable material, and the expansion spring  18  is typically manufactured from a metal or a plastic material. Suitable adhesives, for use with the present invention, are either a  410  or a  480  fast drying super strength adhesive manufactured by Loctite Corporation (e.g., LOCTITE® PRISM  410  Black Toughened Instant Adhesive or LOCTITE® PRISM  480  Black Toughened Instant Adhesive) or some other conventional fast drying super strength adhesive, for example, and a suitable solvent is, for example, acetone or possibly a lacquer based thinner. 
         [0033]    The clearance or spacing between the exterior surface of the gauge plunger  16  and the inwardly facing surface of the gauge body  14  is such that the gauge body  14  permits substantially free relative sliding movement of the gauge plunger  16  while restricting such sliding movement substantially only along the longitudinal centerline or axis A of the expandible gauge  12 . A clearance of between about 0.001 of an inch to about 0.030 of an inch between the exterior surface of the gauge plunger  16  and the inwardly facing surface of the gauge body  14 , generally permits such movement. 
         [0034]    A clearance or spacing between the exterior surface of the gauge adapter  20  and the inwardly facing surface of the tool hole  22  is such that the gauge adapter  20  is temporarily retained within the tool hole  22  along the longitudinal centerline or axis A of the expandible gauge  12 . A clearance of between about 0.001 of an inch to about 0.030, between the exterior surface of the gauge adapter  20  and the inwardly facing surface of the tool hole  22 , generally permits such retention. 
         [0035]    It is to be appreciated that either the gauge body  14  and/or the gauge plunger  16  can have an extension attached thereto for increasing the length of the bore gauge  10  for larger diameter bores. 
         [0036]    As is well known in the art, the tool hole  22  in the bore bar  24  can have a variety of different sizes, etc., be either a ⅜″, a ½″, a 10 mm or a 12 mm square hole or a 16 mm round hole. Since the gauge adapter  20  is designed to be inserted into and retained within the tool hole  22 , the gauge adapter  20  normally has corresponding size so that the gauge adapter  20  can be easily and securely accommodated within the tool hole  22 . Alternatively, the expandible gauge  12  and the gauge adapter  20  may be combined with one another to form a single combined gauge adapter component which is has an exterior shape and size which is suitably sized to be easily and securely accommodated within the tool hole  22  of the bore bar  24 , i.e., the exterior shape and size of the combined gauge adapter component has a close sliding fit within the tool hole  22 . 
         [0037]    Since certain changes may be made in the above described method and system without departing from the spirit and scope of the invention herein involved, it is intended that all of the subject matter of the above description or shown in the accompanying drawings shall be interpreted merely as examples illustrating the inventive concept herein and shall not be construed as limiting the invention.