Abstract:
An apparatus for reconditioning the surface of a workpiece. The frame of the apparatus includes a first portion that is frictionally engaged to the outside diameter of the workpiece and a second portion that rotates relative to the first portion. A cutting tool is mounted to the rotating portion of the frame, and in addition to providing for the alignment of the frame with the workpiece, the present invention provides for the squaring up of the frame with the surface of the workpiece that is to be reconditioned so that the cutting tool will provide a flat, finished surface that is perpendicular to the longitudinal axis of the workpiece. Also provided is a mount for the cutting tool that facilitates fast replacement of the cutting tool while still allowing precise positioning of the cutting tool and minimizing any relative movement between the cutting tool and the mount.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to machining equipment. More specifically, the present invention relates to an apparatus and method for reconditioning the surface of a workpiece, such as a gasket surface, and is particularly useful for reconditioning such surfaces in the field.  
           [0002]    It is known to detachably mount a so-called ring, or facing, machine to, for instance, a pipe or other tubular member for reconditioning the surface, or facing, of the pipe that mates to another surface. Such machines are comprised of a ring or frame that is mounted to the outside diameter, or O.D., of the pipe or tubular member having a movable member mounted thereto to which a cutting tool is mounted for re-facing, or reconditioning, the surface of the pipe or tubular member.  
           [0003]    There are a number of difficulties with the use of such a machine, including the need for precision in the cutting process for reconditioning the surface, the heavy weight of the ring machine, the mounting of the ring machine to the O.D. of the pipe or tubular member in a position that is both aligned with the pipe and squared up to the surface to be reconditioned, and the need for secure mounting of the cutting tool to the ring machine. This list is not intended to be exhaustive, but will serve for the purpose of illustrating some of the difficulties in the use of such machines.  
           [0004]    There are at least two difficulties with prior ring machines to which the present invention is particularly addressed. First with regard to the difficulty in mounting such machines to the pipe or tubular member, there is a need for an apparatus and method of aligning the machine with both the axis of the tubular member and the surface to be reconditioned. In this regard, it is known to use multiple clamps or fixtures to mount the ring machine to the outside diameter of the tubular member, and to use the clamps for minute movement of the ring machine needed to “center” the ring machine on the tubular member. Such centering movement is accomplished by loosening the clamp(s) on one side of the tubular member and tightening the clamps on the other side of the tubular member with the result that the ring member is re-positioned relative to the tubular member. The distance between the O.D. of the tubular member and the ring member is then measured, for instance, using a dial gauge, and then, by repeated loosening and tightening to correct any misalignment between tubular member and ring machine, the ring machine is gradually aligned with the tubular member.  
           [0005]    This process, however, only aligns the center axis of the ring machine with the center axis of the tubular member. It does not square the ring machine up to the surface to be reconditioned. Stated another way, if an X, Y, Z coordinate system is superimposed on the surface to be reconditioned with the X and Y axes lying in the plane of the surface to be reconditioned and the substantially perpendicular Z axis is substantially parallel to the longitudinal axis of the tubular member, conventional ring machines are aligned with the tubular member by moving the ring member in directions substantially in the plane of (or referred to herein as being “substantially parallel” or “having a directional component substantially parallel to”) the X and Y axes by this process of repeated loosening, tightening, and measuring. So far as is known, none of the ring machines that are currently available make provision for moving a portion of the ring machine in a direction substantially parallel to the Z axis to square the ring machine up to the surface to be reconditioned. Due to the weight of the ring machine (ring machines for use on modest size tubular members, for instance, for use in reconditioning the surface of a twenty inch pipe, weigh several hundred pounds, and those used on large diameter pipe approach a ton), the ring machine cannot easily be moved in any direction. For that reason, the process of squaring the ring machine up to the surface to be reconditioned is usually accomplished by loosening one or more of clamps and hammering on the frame of the ring machine near the clamp that has been loosened to “bump” that portion of the frame a short distance in the desired direction. This process is not very precise, and it relies on the weight of the ring machine and the slight loosening of the clamp to prevent drastic movement of the ring machine relative to the surface to be reconditioned, neither of which results in predictable movement and/or limitation of movement, in a direction substantially parallel to the Z axis.  
           [0006]    There is, therefore, a need for a ring machine, and a method of mounting a ring machine to a tubular member for reconditioning a surface that allows precise movement of the ring machine so as to square the ring machine up to the surface to be reconditioned, and it is an object of the present invention to provide such a machine and such a method.  
           [0007]    The second limitation of known ring machines to which the present invention is directed is in the mounting of the cutting tool (which bears against the surface to be reconditioned to cut that surface as it is moved across the surface by the ring machine) to the ring machine. The cutting tool must be mounted to the ring machine in such a way that precise positioning can be achieved and, once positioned, it cannot change position until moved by the operator. Further, the mount must be secure enough to resist vibration, or chattering, of the cutting tool as a result of the impact of the cutting tool on irregularities on the surface to be reconditioned as the cutting tool is moved across that surface. It is recognized that it is impossible to prevent all chattering, but such movement must be minimized to produce a satisfactorily reconditioned surface, and it is well known that the best reconditioned surfaces are those that were reconditioned with a cutting tool with minimal chatter. At the same time, the cutting tool must be capable of being replaced quickly and then accurately re-positioned relative to the cutting surface so as to resume re-facing operations at the same depth of cut such that precision in mounting is an important factor in the mounting of the cutting tool to the ring machine.  
           [0008]    There is, therefore, a need for an apparatus and method for reconditioning a surface of a tubular member that resists vibration, or chatter, of the cutting tool during reconditioning operations while still allowing quick replacement of the cutting tool and accurate positioning of the cutting tool relative to the surface to be reconditioned, and it is an object of the present invention to provide such an apparatus and method.  
           [0009]    Another object of the present invention is to provide an apparatus and method for reconditioning the surface of a tubular member that produces a smooth reconditioned surface.  
           [0010]    Another object of the present invention is to provide an apparatus and method for reconditioning the surface of a workpiece with a cutting tool in which the cutting tool is constantly biased against, or drawn to, the ring machine so as to increase the rigidity of the mount of the cutting tool relative to the ring machine.  
           [0011]    Yet another object of the present invention is to provide an apparatus and method in which the cutting tool used to recondition the surface of a workpiece is quickly and easily replaced so as to increase the speed of the reconditioning operation.  
           [0012]    Other objects, and the advantages, of the present invention will be made clear to those skilled in the art by the following description of the presently preferred embodiments thereof.  
         SUMMARY OF THE INVENTION  
         [0013]    These objects are achieved by providing an apparatus for reconditioning the surface of a workpiece comprising a frame having a shape approximating the shape of the workpiece having a first portion that is fixed relative to the workpiece and a second portion that is movable relative to the workpiece. A plurality of blocks are mounted to the first portion of the frame, each block having a threaded bolt extending therethrough and a jaw mounted to the end of the bolt for engaging the workpiece when rotated to extend the bolt out of said block to the workpiece. The jaw is movable relative to the cylinder in a direction substantially perpendicular to the axis of the bolt to which the cylinder and jaw are mounted. A drop plate is mounted to the second portion of the frame and a compound is detachably mounted to the drop plate for mounting a cutting tool thereon for reconditioning the surface of the workpiece when the second portion of the frame is moved relative to the workpiece.  
           [0014]    The present invention also provides a method for moving a ring machine relative to the surface of a workpiece to reconditioned to square the ring machine up to the surface comprising the steps of frictionally engaging the outside surface of the workpiece by extending a jaw from a block, the block being integral with the ring machine and, while the jaw is frictionally engaged to the outside surface of the workpiece, moving the jaw in a direction substantially perpendicular to the direction the jaw was extended into engagement with the outside diameter of the workpiece, thereby moving the ring machine relative to the workpiece.  
           [0015]    In another aspect, the present invention provides an apparatus for reconditioning the surface of a workpiece comprising a frame for detachably mounting to a workpiece having a surface to be reconditioned, the surface to be reconditioned defining X and Y axes lying substantially in the plane of the surface to be reconditioned and a Z axis substantially perpendicular to the X-Y axes. First means is mounted to the frame for moving the frame relative to the workpiece in directions having a component substantially parallel to the X-Y axes when the frame is mounted to the workpiece for aligning the frame with the workpiece; and second means is mounted to the frame for moving the frame in a direction having a component that is substantially parallel to the Z axis when the frame is mounted to the workpiece for squaring the frame up to the workpiece.  
           [0016]    Also provided is a mount for a cutting tool comprising a compound having a tool holder mounted thereto with a member formed on the compound and having a beveled surface thereon. The apparatus also comprises a pin shaped to engage the beveled surface of the member formed on the compound and a drop plate for mounting to a carriage. The drop plate is provided with a hole therethrough for receiving the beveled member and a hole for receiving the pin, the pin locking the compound to the drop plate by engaging the beveled surface of the member when received in the hole in the drop plate. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a front perspective view of a preferred embodiment of an apparatus for re-facing a surface that is constructed in accordance with the teachings of the present invention and that is mounted to the outside diameter of a pipe.  
         [0018]    [0018]FIG. 2 is a back perspective view of the apparatus of FIG. 1.  
         [0019]    [0019]FIG. 3 is a perspective view of a preferred embodiment of a clamp for mounting the presently preferred embodiment shown in FIG. 1 to the O.D. of a pipe or other tubular member.  
         [0020]    [0020]FIGS. 4 and 5 are side, elevational views of the clamp of FIG. 3.  
         [0021]    [0021]FIG. 6 is an exploded, perspective view of the clamp of FIG. 3.  
         [0022]    [0022]FIG. 7 is a perspective view of a presently preferred embodiment of a mount for a cutting tool for use with the presently preferred embodiment shown in FIG. 1.  
         [0023]    [0023]FIG. 8 is a sectional view, taken along the lines  7 - 7 , of the mount of FIG. 6.  
         [0024]    [0024]FIG. 9 is an exploded, perspective view of the mount of FIG. 6.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    Referring first to FIGS. 1 and 2, a preferred embodiment of an O.D. mount facing machine constructed in accordance with the teachings of the present invention is indicated generally at reference numeral  10 . The apparatus  10  comprises a frame  12  shaped to approximate the shape of a tubular member, or workpiece,  14  having a surface  16  thereon to be reconditioned, or re-faced. As set out in more detail below, frame  12  is comprised of first and second portions  12   a  and  12   b , the portion  12   a  being provided with means, in the form of a plurality of clamps  18 , for engaging the surface, or outside diameter (O.D.),  20  of workpiece  14 , and the portion  12   b  being movable relative to the portion  12   a . The stationary, or fixed, portion  12   a  of frame  12  is provided with a plurality of bearings  22  against which the outside surface  24  of the second portion  12   b  of frame bears and a mount  26  for an air motor  28 . Although not visible in either of FIGS.  1  or  2 , the mount  26  is also provided with an idler for a belt that is wrapped around the rotatable portion  12   b  of frame  12  to rotate the portion  12   b  relative to the stationary portion  12   a  of frame  12  under power from the air motor  28 . Those skilled in the art will recognize that other drive arrangements known in the art may also be utilized for rotating frame portion  12   b  relative to frame portion  12   a.    
         [0026]    A cross-arm  30  is mounted to the rotating portion  12   b  of frame  12  and a track  32  is provided on one side of cross-arm  30  with a carriage  34  running on track  32 . The position of carriage  34  on track  32  is controlled by rotation of adjustment wheel  36 , which turns a worm gear (not visible in the figures) for moving the carriage  34  along track  32  in a manner known in the art. The carriage  34  is provided with apparatus, indicated generally at reference numeral  38 , for mounting a cutting tool  40  thereto. In the embodiment shown, apparatus  38  is comprised of a drop plate  42  and compound  44 , the latter providing a mount for tool holder  46 , all to be described in more detail below. The height of the cutting tool  40  relative to the surface  16  of workpiece  14  is adjusted by turning the wheel  48  in a manner that is also known in the art.  
         [0027]    Referring now to FIGS. 2-6, the clamps  18  and their function will now be described in detail. Each clamp  18  is comprised of a block  50  that is provided with a plurality of holes  52  for receiving bolts (not shown) for mounting clamp  18  to the first portion  12   a  of frame  12 . Each block  50  is also provided with a bore  54  extending longitudinally therethrough for receiving a threaded bolt  56  having a jaw  58  mounted to the end thereof and extendible therefrom upon rotation of bolt  56  relative to block  50 . As best shown in FIG. 5, bolt  56  is provided with two sets of threads, a first set of right-hand threads  60  and a second set of left-hand threads  62 . The right-hand threads  60  of bolt  56  mate with the threads  64  on the inside surface of a bushing  66  that is received within the bore  54  through block  50  and pinned in place in block  50  by the tapered dowels  68  that are received in the holes  70  that extend down into block  50 . When bushing  66  is assembled to block  50  in bore  54  and the dowels  68  are inserted into the holes  70  in block  50 , the dowels  68  are received in the channels  72  formed on the outside surface  74  of bushing  66 . The channels  72  form flats that, when engaged by dowels  68 , prevent rotation of bushing  66  relative to block  50  when bolt  56  is rotated.  
         [0028]    The left-hand threads  62  of bolt  56  mate with the threads  76  inside the cylinder  78  that is also received within the bore  54  through block  50 . Cylinder  78  is comprised of a barrel  80  in which the bolt  56  is received (on the threads  76 ) and a head  82  to which jaw  58  is mounted The barrel  80  of cylinder  78  is provided with a keyway  84  for receiving an anti-rotation pin  86  that extends through the hole  88  (see FIG. 5) in the side of block  50 . Anti-rotation pin  86  prevents rotation of cylinder  78  relative to block  50  when bolt  56  is rotated, thereby causing cylinder  78  to move through the bore  54  in block  50  to extend the jaw  58  mounted to the head  82  thereof out of the block  50  as shown in shadow lines  90  in FIG. 4 and into frictional engagement with the O.D.  20  of workpiece  14 .  
         [0029]    Also as best shown in FIG. 6, the head  82  of cylinder  78  is shaped to receive the mating surface  92  of jaw  58 . Mating surface  92  is provided with opposed flanges  94  that are received within appropriately-sized slots  96  formed in the head  82  of cylinder  78  to form a track upon which jaw  58  rides up and down (in a manner to be described below) in the direction shown by arrow  98  that is substantially perpendicular to the direction (shown by arrow  100 ) the jaw  58  is extended upon rotation of bolt  56  into engagement with the O.D.  20  of workpiece  14 . Jaw  58  is retained upon the track formed by the head  82  of cylinder  78  and the mating surface  92  of jaw  58  by a thrust plate  102  that is mounted to jaw  58  by the cap screws  104  that are received in the holes  106  formed in jaw  58 . Movement of the jaw  58  in the direction of arrow  98  is accomplished by rotation of the socket head lead screw  108  that extends through thrust plate  102  and is received in the threaded bore  110  in jaw  58 . A nut  112  received on lead screw  108  is pinned against rotation by a roll pin  114  that extends through nut  112  and into lead screw  108  and sandwiches a brass washer  116  against thrust plate  102  to allow rotation of lead screw  108  to cause the movement of jaw  58  along the threaded bore  110  in the direction of arrow  98 , even while the jaw  58  frictionally engages the O.D.  20  of workpiece  14 .  
         [0030]    It will be apparent from the foregoing description that the movement of jaw  58  in the direction of arrow  98  by interaction of the lead screw  108  and the threaded bore  110  provides the apparatus  10  of the present invention with the ability to move the frame  12  in both the direction needed to center the frame on the center axis of the tubular member/workpiece  14  and the direction needed to square the frame  12  up with the surface  16  to be re-faced with the apparatus  10 . In other words, if an X-Y-Z coordinate system is superimposed on the surface  16  of workpiece  14  with the X and Y axes lying substantially in the plane of surface  16  and the Z axis being substantially perpendicular to the X and Y axes, rotation of the bolt  56  extending through the block  50  of clamp  18  causes the frame  12  to move in a direction that is substantially parallel to either the X or Y axes, depending upon the location of the clamp  18  on frame  12 . In actual practice, the movement of frame  12  relative to surface  16  is in a combination of X-Y directions depending upon which clamps  18  have been loosened and which clamps are then tightened by rotation of their respective bolts  56 . This movement of frame  12  in directions having a component substantially parallel to the X and Y axes of this imaginary coordinate system is known in the art; it is the movement of the frame  12  relative to surface  16  in a direction having a Z component that is, so far as is known, not previously available in any O.D. mount facing machine. With reference to FIG. 6, the movement of frame  12  in directions having X and/or Y components is movement that is accomplished by movement of the cylinder  78  along the left-hand threads  62  of bolt  56  in the direction of arrow  100 . Movement of frame  12  in a direction having a Z component (in the direction of arrow  98 ) is, as noted above, accomplished by movement of the jaw  58  along the threaded bore  110  upon rotation of lead screw  108  (see FIG. 5).  
         [0031]    Referring now to FIGS. 7-9, a presently preferred embodiment of an apparatus for mounting a cutting tool (not shown in FIGS. 7-9; see reference numeral  40  in FIG. 1) is indicated generally at reference numeral  38 . The mount  38  is comprised of a compound  44  having a tool holder  46  mounted thereto and a drop plate  42  for mounting, in the particular embodiment shown, to the carriage  34  that runs on the track  32  formed on cross-arm  30 , and a plurality of holes  118  for receiving bolts (not shown) are provided in drop plate  42  for that purpose. However, those skilled in the art who have the benefit of this disclosure will recognize that the mount  38  of the present invention is not limited in its application to mounting a cutting tool to the carriage of an O.D. mount facing machine such as the apparatus  10  shown herein. Instead, it should be clear from this description that the mount  38  may be utilized to mount a cutting tool to any machine tool.  
         [0032]    The tool holder  46  is mounted to compound  44  by sliding the tongue  120  formed on tool holder  46  into a matching groove  122  formed on compound  44  and locking the tool holder  46  in place with the screws  124  that are received through the holes  126  on cover plate  128  and through the holes  130  in the tongue  120 . It will be recognized, however, by those skilled in the art that other ways are known in the art to mount the tool holder  46  to a compund such as the compound  44 , or to other machine parts (not shown) and that the present invention is not limited to the particular mount shown in the figures.  
         [0033]    In more detail, a member  132  (see FIGS. 8 and 9) is formed on one side of compound  44  having a beveled, or undercut surface, indicated at reference numeral  134 . In the embodiment shown, the member  132  takes the form of a round, or substantially rounded, projection extending from the side of compound  44  opposite the side to which tool holder  46  is mounted. Member  132  extends into a hole  136  in drop plate  42  when compound  44  is assembled to drop plate  42  and a draw pin  138 , or in the case of the preferred embodiment shown in the figures, two draw pins  138 , are pressed down into the bores  140  provided for that purpose in drop plate  42 . As best shown in FIG. 9, a portion of each of the bores  140  intersects with the hole  136  so that the draw pins  138  engage the undercut surface  134  of member  132  to lock the compound  44  in place relative to drop plate  42 . The engagement of the undercut surface  134  by draw pins  138  also biases the compound  44  against drop plate  42  to minimize the likelihood of relative movement therebetween. In addition to minimizing any such movement, this arrangement also provides for quick changeout of the cutting tool because the draw pins  138  are provided with a flat  142  positioned proximate the hole  136  when inserted into the bores  140  in drop plate  42  and a socket head  144  so that the draw pins  138  can be turned to allow the flared portion of member  132  to pass the draw pins  138 . As a result of this construction, a light tap on compound  44  with a hammer (after rotating the draw pins  138 ) is generally all that is required to separate the compound from drop plate  42  even though the two parts are securely mounted to each other. Those skilled in the art will recognize from this description that the compound can be assembled to other machine tools having a hole  136  shaped and sized to receive the member  132  and bores  140  for receiving the draw pins  138  such that, when reference is made herein to a “drop plate” such as is shown at reference numeral  42 , it is not intended to restrict the mount of the present invention to the mounting of a compound to a drop plate. For instance, it will be recognized by those skilled in the art that the hole  136  could be formed in the carriage  34  that rides on the cross-arm  30  of the O.D. mount facing apparatus  10  of the present invention and that the bores could be provided on that carriage for receiving the draw pins  138  such that the compound  44  is mounted directly to carriage  34  without having a drop plate such as the drop plate  42  interposed therebetween. For this reason, when reference is made herein to a mount for a cutting tool that includes a drop plate, it is to be understood that the phrase “drop plate” is being used in the generic sense to refer to any portion of a machine tool to which the cutting tool is to be mounted and that interacts with the compound in the manner described herein.  
         [0034]    Those skilled in the art who have the benefit of this disclosure will recognize that certain changes can be made to the component parts of the apparatus of the present invention without changing the manner in which those parts function to achieve their intended result. For instance, with respect to the mount  38  described herein, the bores  140  in drop plate  42  need not extend vertically down through the drop plate  42 ; the draw pins  138  will function for the intended purpose of locking the compound  44  to drop plate  42  if the bores  140  extend from the sides of drop plate  42 . It will also be recognized that the member  132  could extend from the surface of drop plate  42  into a hole formed in compound  44  and that the draw pins  138  could extend down through bores in the compound  44  to lock the drop plate and compound to each other. It will also be apparent that the member  132  need not necessarily be round; those skilled in the art will recognize that there may even be mechanical advantages to shaping the member  132  so that it is elongated (oval or elliptically-shaped, or even squared-off, when viewed in elevational view from the side that is assembled to drop plate  42 ) in a direction substantially parallel to the direction in which the draw pins  138  extend so as to increase the size of the undercut surface  134  against which draw pins  138  bear. With respect to the clamp  18  described herein, it will be recognized that the bushing  66  could be provided with a tapered surface and that the dowel pins  68  that lock the bushing  66  into the bore  54  through block  50  and resist rotation of bushing  66  could therefore interact in the same manner as the draw pins  138  interact with the beveled surface  134  of member  132  to prevent relative movement therebetween. Similarly, it may be advantageous to provide the dowel pins  68  with socket heads and flats in the same manner as the draw pins  138  for the same purpose. All such changes, and others which will be clear to those skilled in the art from this description of the preferred embodiments of the invention, are intended to fall within the scope of the following, non-limiting claims.