Abstract:
An alignment tool for adjustably positioning a boring bar relative to a spaced apart fixed location on a structural member including an elongated bar formed of a plurality of axially aligned and separable tubular members and having its opposite ends mounted to the boring bar and the fixed location, respectively. The length of the bar, hence the distance between the boring bar and the fixed location is adjustably selectable by means of telescopically mounted one of the tubular members. A first one of the tubular members receives therein a second one of the tubular members employing a thread interconnection whereby rotational movement of one tubular member relative to the other provides selection of the overall length of the tool. Multiple indicia associated with the outer circumference of each of the threadably interconnected tubular members provide a visual indication of the extent of the insertion of said second tubular member within said first tubular member, hence the overall length of the tool.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   This invention relates to apparatus for boring of a new hole or reboring of an existing hole in a workpiece wherein the new hole or the hole to be rebored is spaced apart from a different hole or other location on the workpiece. That is, the workpiece may exist with two holes therein, one or both of which need to be rebored, or the workpiece may have a first hole and may need a second hole bored in the workpiece at a location which is to be precisely spaced-apart from the first hole. Commonly, the present invention is employed in combination with a portable boring bar. 
   U.S. Pat. No. 5,785,466 (the &#39;466 patent) discloses a tool for aligning a portable boring bar for reboring one or more existing holes in a workpiece. As disclosed in the &#39;466 patent, the need for the aligning tool is frequently found when repairing heavy earth-moving type machinery which employs articulating joints as a part of the machine. The &#39;466 patent is incorporated herein in its entirety by reference. 
   As pointed out in the &#39;466 patent, in many applications, the points of articulation include multiple bores. In substantially all instances, the articulating joint includes two structural items, one of which is articulated relative to the other item, and each structural item has its own set of bores. The bores of a first set are disposed in a first structural member of the machine and the second set of bores are disposed in a second structural member of the same machine. For articulation of the first and second structural members, the bores in one set must be in register with the bores of the second set and some form of pin or other removable connector passed through the registered bores to define the articulation joint. Thus, the axes of the bores of a first set must be parallel to one another, must be perpendicular to an outer surface of their structural member, and spaced apart by a precise distance. Likewise, the axes of the bores of the second set must be parallel to one another and perpendicular to an outer surface of their structural member, and spaced apart from one another by a precise distance, such distance being precisely equal to the distance separating the bores of the first set. 
   The present inventor has found that it is also of importance that, when reboring a bore it is most important that the axis of the resultant rebored bore not only be parallel to the axis of a second (or base) bore, but the distance between the axis of the base hole and the axis of the rebored bore be spaced apart by a very precise distance. Failure to form the bores of a first set of holes in a first structural item with their axes both parallel to one another and precisely spaced apart, and to form the holes of the second set of holes in a second structural item with their axes both parallel to one another and precisely spaced apart by the same distance at which the holes in the first set are spaced apart, results in failure of the rebored hole and the base hole of the first set of holes in the first structural item to line up (be in register) with matching holes in a second set of holes in the second structural item. This misalignment of the bores can result in malfunctioning of the articulation action of the joint. 
   By “precisely”, it is meant that the distance between any two holes of a set should be equal to the desired spacing ±0.01 inch or better. The significance of this degree of precision will be recognized when one notes that the structural items involved in the articulating joint of a piece of heavy duty earth moving machinery weighs hundreds of pounds and are relatively huge in bulk, hence they must be manipulated by a crane or other mechanical lifting and positioning device when being assembled. Accordingly, failure to provide precisely positioned and parallel holes (bores) in both of the structural elements may completely preclude the joining of the articulating structural elements, or may result in improper alignment of these elements and resulting undue wear of the holes due to their misalignment. Also, importantly, when assembling the heavy and huge structural items, a worker&#39;s manual attempts to move or rearrange the structural items to align their respective sets of holes can be frustrating, but more importantly, can result in serious injury to the worker. 
   Accordingly, there is a need in the industry for a tool which is capable to aligning first and second holes, with their respective axes being parallel to one another and precisely spaced apart from one another. 
   BRIEF SUMMARY OF THE INVENTION 
   In accordance with one aspect of the present invention, there is provided an alignment tool for use in the precise alignment of at least a first hole in a structural member of an item of heavy duty machinery relative to a second hole or other location on the structural member. The alignment tool of the present invention includes at least a first hollow tubular segment which houses centrally thereof a rigid externally threaded rod which is anchored to one end of the first segment and extends in cantilevered fashion from its anchored location along substantially the entire length of the first segment, and a second hollow tubular segment telescopically received within the first tubular segment. The second segment circumscribes the internal rigid rod of the first segment and includes an internally threaded plug in that end of the second segment which is received within the first segment, such plug acting as a lead nut threaded onto the rigid rod. The depth of insertion of the second tubular segment within the first tubular segment is selectable by rotation of the second segment relative to the first segment to adjust the overall length of the alignment tool. Venier means is provided to visually observe and thereby select the overall length of the alignment tool to within about 0.01 inch increments. The opposite outboard ends of the first and second tubular segments, preferably are provided with tubular extensions thereof which are provided with receptors for releasably anchoring the receptors to, and extending between, first and second elements of a portable boring bar, for example, to precisely establish the separation distance of such elements of the boring bar, hence the separation distance of a hole to be bored or rebored from a spaced-apart location relative to the hole. The alignment tool is particularly useful in combination with the tool disclosed in U.S. Pat. No. 5,785,466. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a representation of a tool embodying various of the features of the present invention; 
       FIG. 2  is an exploded representation of the tool depicted in  FIG. 1 ; 
       FIG. 3  is a cross-sectional, side elevation, view of a portion of the tool depicted in FIG.  1  and taken generally along the line  3 — 3  of FIG.  1  and depicting first and second telescoping tubular elements; 
       FIG. 4  is a further side elevation view of a portion of the tool taken generally along line  3 — 3  of FIG.  1  and depicting a cutaway of a portion of said tool; 
       FIG. 5  is a side elevational view, in cross-section of the right hand tubular element of  FIG. 3 ; 
       FIG. 6  is a side elevational view, in cross-section, of a clamp post interposed between the right-hand end clamp and an adjacent one of the first and is second tubular members depicted in  FIG. 3 ; 
       FIG. 7  is a side elevational view, in cross-section, of a further clamp post member interposed between the left-hand end clamp and an adjacent one of the first and second tubular members depicted in  FIG. 3 ; 
       FIG. 8  is a side elevational view, in cross-section of an extension segment in association with an embodiment of the present invention. 
       FIG. 9  is a representation of an articulation joint between first and second structural members of a typical earth-moving machine; 
       FIG. 10  is a top plan view of a tool designed to position a portable boring bar as described in U.S. Pat. No. 5,785,466; and, 
       FIG. 11  is a representation of one embodiment of a tool of the present invention as employed in combination with an tool designed to mount a portable boring bar. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A typical articulating joint  10  found in a heavy duty earth-moving machine, such as a common tractor-pulled pan, is depicted in FIG.  9  and includes a first structural hitch member  12  associated with the rear end of the tractor, a second structural hitch member  14  associated with the front end of the pan, and a third structural hitch member  16  interposed intermediate the first and second elements. These first and third hitch members are connected in articulating relationship by first, second, third and fourth connector strips  18 , 20 , 22 , 24 . Typically, a first end  26 , 27  of each of the first and second connector strips  18 , 20  are rotatably pinned by a pin  28  which passes through a first hole (bore)  31  through the thickness of the second hitch member  14  associated with the pan. In like manner, the first end  32 , 34  of each of the third and fourth connector strips  22 , 24  are pinned by a pin  30  which passes through a second hole (bore)  36  through the thickness of the second hitch member associated with the pan, the axes of the first and second holes  31 , 36  being both parallel and spaced-apart from one another by a precise distance. 
   The opposite ends  38 , 40  of the first and second connector strips are pinned to the trailing margin  42  of the third hitch member  16  by a pin  44 , which passes through a hole  46  through the thickness of the third hitch member. In like manner, the opposite ends  48 , 50  of the third and fourth connector strips  22 , 24  are pinned by a pin  52  to the trailing margin  42  of the third hitch member. The axes of these holes  36 , 52  are both parallel and spaced apart from one another by a precise distance. Moreover, desirably, the axes of the holes  31 , 32  through the second hitch member  14  are parallel to one another and are also aligned perpendicular to the outer face  54  of the second hitch member. In like manner, the axes of the holes through the third member are also aligned perpendicular to the outer face  56  of the third hitch member. Thus, when the outer faces  54 , 56  of the second and third members are planarly aligned, the axes of the holes through the second member and the axes of the holes through the third member are aligned parallel to one another, thereby making assembly of the second and third hitch members to one another a relatively easy, task. 
   In  FIGS. 10 and 11 , there is depicted one embodiment of a boring bar mounting tool  60  as disclosed in the &#39;466 patent. As disclosed in the &#39;466 patent, this tool is designed to be mounted on the outer face of a structural element to permit either reboring of an existing hole through the thickness of the structural element or to bore a new hole through the thickness of the structural element, in either event, the rebored hole or the new hole is to be spaced-apart a precise distance from an existing hole. Among other elements, the tool depicted in  FIGS. 10 and 11  includes first and second side elements  62 , 64 , each of which is hinged approximately centrally  66  thereof. The first and second side elements are rigidly interconnected parallel and spaced-apart from one another by multiple cross members  68 , 68 ′ (typical). Each side member includes a first end  70  ( FIG. 11 ) which-defines a first set generally cylindrical mountings  72 , 74  for rotatably receiving therein a boring bar  76  and a second end  70 ′ which defines a second set of generally cylindrical mountings  7274 ′ for rotatably receiving therein a rigid alignment bar  78 . The boring bar is rotatably driven about its longitudinal axis or by a portable motor  79 . 
   In  FIGS. 10 and 11 , it is noted that a straight rigid boring bar  76  is fed through the mounts  72  and  74  on the first end of the side members of the mounting tool. In like manner, a straight rigid alignment bar  78  is fed through the mounts  72 ′ and  74 ′ on the second end of the mounting tool. It will be recognized from  FIGS. 10 and 11  that the longitudinal axes  80 , 82  of these two rigid straight bars provide loci for the establishment of the distance between such two bars; hence establishment of the distance between the axis of a first hole (into which one end of the alignment bar is inserted) and a second hole to be rebored, or the location of the axis of a new hole to be bored by the boring bar  76  all as more fully described in the &#39;466 patent. 
   Accordingly, in accordance with one aspect of the present invention, there is provided a length-adjustable alignment tool  100  for the setting and retention of the separation distance between the boring bar and the alignment bar of a tool, such as that disclosed in the &#39;466 patent, for example. 
   Referring to  FIG. 1 , there is depicted one embodiment of an adjustment tool  100  of the present invention. 
   The depicted tool generally includes a first end  102  adapted to be attached to a boring bar, for example, and a second and opposite end  104  adapted to be attached to an alignment bar and a central body portion  106  interposed between the opposite ends. 
   Referring specifically to  FIGS. 1 and 3 , the central body portion  106  of the depicted embodiment of the tool includes a first rigid hollow tubular segment  108  having a first (outboard) end  110  and a second (inboard) end  112 . The first (outboard) end  110  of the segment is closed by a shouldered sleeve  114 , such shoulder abutting the circumference of the end of the segment  108  and limiting the extent of insertion of the sleeve into the segment. The sleeve  114  is anchored within the end of the tube as by press fitting, threading or other equivalent and suitable anchoring technique. The shoulder  116  of the sleeve  114  is centrally bored  118  and provided with threads  120  on its outer circumference. 
   As depicted in  FIGS. 3 and 4 , a rigid externally threaded rod  122  is disposed within the interior of the first segment  108 . A first end  124  of the rod is threaded  126  into the internally threaded bore  118  of the plug  114  and pinned against lateral rotational or longitudinal movement relative to the plug  114 , hence relative to the first segment  108 , as by a roll pin  128 . This rod extends coaxially along substantially the entire length of the first segment in cantilevered fashion and terminates short of the second end  112  of the first segment. 
   A second segment  129  of the central body portion  106  of the present tool comprises a rigid hollow tube  130  having an outer diameter suitable to permit the tube to snugly, but readily slidably, be received within the interior  132  of the first segment  108 . Referring specifically to  FIGS. 3 ,  4  and  5 , this second tubular segment  129  includes a first (inboard) end  134  which receives therein a shouldered sleeve  136 . The shoulder  138  abuts the circumference of the end  134  and functions to limit the extent of insertion of the sleeve into the interior of the inboard end  134  of the second segment. The sleeve is anchored within the end of the second segment by press fitting or other suitable means which ensures that the sleeve is secured within the second segment and is fixed against rotational movement relative to the second segment. Further, the sleeve is provided with internal threads  140  which are complementary with the external threads  126  on the cantilevered rod  108  so that telescopic insertion of the second segment into the first segment is effected by rotation of the second segment relative to the first segment by means of the internally threaded sleeve functioning as a lead nut threaded onto the externally threaded rod  122  held fixedly in the first segment. 
   As seen in  FIGS. 3 and 5 , the outboard end  141  of the second segment  129  is fitted with a shouldered plug  143 . The shoulder  145  of the plug projects axially outwardly beyond the outer circumference of the body portion  312  of the second segment. As depicted  FIG. 4 , the external circumference of the second segment is marked with a straight line  150  which is parallel to the longitudinal axis  152  of the second segment and which is located on the exterior circumference of the second segment in ready visible accessability to a user of the tool. Moreover, this line is intersected at equally spaced locations along its length, for example, one inch increments, by lines  154  (typical) on the outer circumference of the second segment and which are oriented perpendicular to the longitudinal line  150 . These lines function to visually divide the length of the second segment into equal divisions  156  (typical) useful in visually observing the extent of telescopic insertion of the second segment into the interior of the first segment. Further, as seen in  FIG. 4 , the circumferential margin  160  of the outboard end of the first segment is provided with equally spaced apart lines  162  (typical) which, in combination with the longitudinal line on the outer circumference of the second segment, serve as indicia of the extent to which a given division  156  of the second segment is inserted into the interior of the first segment. Preferably, the spacing between adjacent ones of the lines  162  on the outer circumference of the end  112  of the first segment is chosen such that the total of all such spacings is equal to the length of each division  156  defined on the second segment, in the form of a micrometer-type measurement, thereby providing for precision selection of the extent of telescopic insertion of the second segment into the first segment, hence defining a means by which the overall length of the tool can be selected very precisely. 
   As desired, the outboard end  110  of the first tubular segment  10  may be provided with one or more tubular extension segments  170  which are joined in axial alignment with the longitudinal axis  152  of the first and second segments. 
   Referring to  FIG. 8 , the inboard end of the first extension segment  170 , is closed by a shouldered plug  172  whose body portion  174  is press fitted into the open inboard end  176  of the extension segment. The diameter of the shoulder  178  of the plug  172  is greater than the outer diameter of its extension segment  170  so that a circumferential portion  177  of the shoulder of the plug projects axially past the outer circumference of the inboard end  176  of the segment  170 . A tubular lock nut  180  is provided in encircling relationship to the outer circumference of the first extension segment  170  to effect releasable joinder of abutting end face  182  of the sleeve  114  in the outboard end of the first segment and the face  184  of the plug  174  inserted in the inboard end of the first extension segment. As depicted in  FIG. 8 , one end  186  of the tubular lock nut  180  includes internal threads  188  which are complementary to the external threads  120  on the circumferential flange of the sleeve  114  disposed in the outboard end of the first segment so that the lock nut may be threadably joined to the sleeve  114 . The opposite end  190  of the lock nut  180  includes an axially inwardly directed flange portion  192  which engages the axially outwardly projecting shoulder  178  on the plug  172  which is fixedly held within the inboard end  176  of the first extension segment. Thus, it will be recognized that by threading the lock nut onto the sleeve  114 , the abutting faces of the sleeve  114  and the plug  172  in the inboard end of the first extension sleeve are pulled together and held against either separation or movement relative to one another. 
   In the depicted embodiment of  FIG. 7 , the tool of the present invention is provided with a second rigid tubular clamp post  200  which functions to fixedly secure the outboard end  110  of the first extension segment  170  to a first end clamp  204 . Specifically, this second clamp post, in one embodiment, comprises a rigid hollow tube  206 , the first (inboard) and second (outboard) ends  208 , 210  of which are fitted with respective shouldered plugs  212  and  214 . In the embodiments depicted in  FIG. 7 , the shoulder  216  of the plug  212  disposed within the inboard end  208  of the tube  206  projects axially beyond the outer circumference of the body portion  215  of the tube, whereas the outer circumference of the plug  214  which is disposed within the outboard end  210  of the tube is flush with the outer circumference of the tube. The body portion  215  of the tube is circumscribed by a lock nut  172  (see also  FIGS. 3 and 4 ) adapted to threadably engage external threads  218  on a plug  220  disposed in the outboard end  202  of the first extension segment  170  and the axially outwardly projecting portion of the circumference of the shoulder  216  of the plug  212  to draw the outer faces  222 , 224  of the plugs  212  and  220 , respectively, snugly together to fixedly secure the first clamp tube in axial alignment with the first extension segment  170 . The plug  214  disposed in the outboard end  210  of the first clamp tube  200  is centrally bored  226  and provided with internal threads  228 . 
   As depicted in  FIG. 6 , in one embodiment, there is provided a first clamp post  232  which comprises a rigid, hollow, tube  234  having its first (inboard) end  236  fitted with a shouldered plug  238 , the shoulder  240  thereof projecting radially beyond the outer circumference of the body portion  242  of the tube and being provided with external threads  244  on its outer circumferential surface. The second (outboard) end  246  of the first clamp post  232  is fitted with a shouldered plug  250 , the outer circumference of the shoulder  252  being flush with the outer circumference of the tube. This plug is axially bored  254  and provided with internal threads  256 . 
   Referring to  FIGS. 1 and 2 , each of the opposite ends  102 , 104  of the tool of the present invention includes a clamp  204 , 205  which is adapted to engage and grasp either a boring bar or an alignment bar of a portable boring bar, for example. To this end, each of these clamps,  205  for example, comprises a top clam shell half  260  having lugs  262 , 264  projecting radially therefrom on diametrically opposite sides thereof, each of the lugs being bored  266 , 268  for receipt therein of threaded fasteners  270  and  272 . Each clamp further includes a bottom clam shell half  280  which also has lugs  282 , 284  projecting radially therefrom on diametrically opposite sides thereof and which are bored  286 , 288  for the receipt of the aforesaid fasteners  270 , 272  therethrough. The lugs  282 , 284  of the bottom clam shell half  280  may be straight bored, in which case nuts  294  (typical) are employed in combination with the fasteners to draw the two clam shell halves together and in engagement with a boring bar or an alignment bar disposed between the halves. Alternatively, the bores through the lugs on the bottom clam shell half may be threaded to threadably receive the fasteners therein. The bottom clam shell half, in the depicted embodiment, is provided with a short post  298  centrally thereof which projects outwardly from the bottom clam shell to abuttingly engage the outer face  252  of the plug  250  disposed within the outboard end of the clamp post  232 . Securement of the bottom clam shell half to the clamp post is provided by means of a bolt  300  which is threadably fed through a central threaded bore  302  in the post, thence into the internally threaded bore  254  in the plug  250  in the outboard end of the clamp post. 
   As seen in  FIG. 7 , the inboard end  236  of the clamp post  232  which is associated with the second segment  129  of the tool is releasably connected to the inboard face  306  of the inboard shouldered plug  240  in the inboard end  236  of the clamp post  232 . In the embodiment of the invention depicted in  FIG. 6 , the inboard end  236  of the clamp post  232  associated with the second segment  129  of the tool, includes a shoulder  240  having threads  244  on its outer circumferential surface. In this embodiment, a lock nut  310  is provided in circumscribing relationship to the body portion  312  of the second segment  129  with its radially inwardly projecting shoulder  314  engaging the outwardly projecting shoulder  145  of the plug  143  disposed within the outboard end  141  of the second segment  129  and with its internal threads  316  on its opposite end engaging the threads  244  on the outer circumference of the shouldered plug  238  which is fitted in the inboard end  236  of the clamp post  232 . This releasable joinder of the abutting ends of the second segment and the clamp post is important in the present invention inasmuch as it will be recognized that, in use, when the lock nut  310  is tightened to draw the ends of the second segment and the clamp post together, these components become rigid with one another, both axially and rotationally. On the other hand, when the lock nut is loosened, the second segment will remain axially aligned with the clamp post, but may readily be rotated relative to the clamp post and relative to the first segment within which the second segment is received. 
   As depicted in  FIG. 6 , in use, after the end clamps  204 , 205  have been affixed to their respective ones of the boring bar  76  and the alignment bar  78  of the portable boring tool  60 , by rotating the second segment relative to the first segment, one can adjust the overall length of the alignment tool within the range afforded by the distance which the body portion of the second segment can enter or exit the interior length of the first segment. This distance can be preselected over a large range, but one example is about 20 inches. To this end, the precision with which the overall length of the alignment tool can be adjusted is enhanced by means of the vernier markings provided on the outer circumference of the end of the first and second segments of the tool. In the depicted embodiment, there are indicia  100  disposed equidistantly apart about the outer circumference of the end  112  of the first segment  108 . Along the length of the outer circumferential surface of the body portion of the second segment  129 , the longitudinally aligned line  150  provides a “zero” line which serves as a base line from which the readings are taken from the indicia  100  on the outer circumference of the first segment. By this means, one can readily adjust the overall length of the alignment tool to a precision of 0.001 inch or better. 
   Clamping of the second end of the present tool to a respective one of the boring bar and alignment bar of the portable boring bar, for example, is effected in like manner as described hereinabove for clamping of the first end of the tool to a boring bar or alignment bar. One difference between the clamping of the first and second ends of the tool is that when clamping the second end to its respective bar, the clamp post employed includes a non-threaded shouldered plug in the inboard end of the clamp post to facilitate assembly of the several elements of the present tool. 
   The present alignment tool is readily applied to a portable boring bar, for example, and easily and precisely adjusted in length after the alignment tool has been applied to the portable boring bar by reason of the selective rotational mounting of the second segment relative to the first segment and the clamp post  232 . As depicted in  FIG. 11 , as desired, a length adjustment tools  100 ,  100 ′ of the present invention preferably are employed on opposite sides of a boring bar. 
   Notably, each of the first and second segments, any extension segments, and/or clamp posts may be selected of any desired length, thereby increasing the versatility of the tool. Preferably each of these elements of the tool are fabricated of a metal. 
   Whereas the present invention has been described in specific terms and examples, it will be recognized by one skilled in the art that various modifications may be made in the structural make-up of the tool without departing from the invention. For example, whereas one or more of the hollow tubular segments, clamp posts and/or extensions may be formed from solid rods which are end bored to provide for interconnection of these elements with or without employing complementary threads between adjacent elements of the tool.