Abstract:
A radially adjustable drive bracket ( 126 ) is affixed to, and rotatable with the drive gear ( 32 ), and a radially adjustable support bracket ( 128 ) is affixed to, and rotatable with the driven gear ( 42 ). A pair of parallel slide rails ( 30 ) are coupled at opposite ends to the drive bracket ( 126 ) and support bracket ( 128 ). A cutting head assembly ( 28 ) is slidably mounted on the slide rails ( 30 ), wherein a threaded lead screw ( 124 ) carrying a traveling nut ( 134 ) thereon causes longitudinal displacement of the cutting head assembly ( 28 ) along the slide rails ( 30 ). A cam arm ( 140 ) coupled through a one-way clutch to the lead screw ( 124 ) and adapted to be actuated by a tripper assembly ( 136 ) mounted so as to engage the cam arm ( 140 ) during orbiting movement of the drive and driven gear ( 32,   42 ).

Description:
FIELD OF THE INVENTION 
     This invention relates generally to an apparatus for machining bearing surfaces of rotating shafts of large machines, and more particularly to a portable journal turning lathe that is adapted to repair and refurbish a tapered work piece and that can be readily transported to a worksite, assembled in place on the tapered work piece to be machined, and then operated to remove any scoring and other surface irregularities from the shaft so that it is ready for replacement of its bearings. 
     DISCUSSION OF THE PRIOR ART 
     It often becomes necessary to refurbish the journal area on a shaft of large machines such as rock crushers or ship rudders. In the past, as described in U.S. Pat. No. 5,660,093, it was necessary to tear down the machine and transport the shaft to a machine shop where it may be machined by an engine lathe weighing 90 tons or more. This process of refurbishing the work piece inherently increased the downtime of the machine being refurbished. The &#39;093 patent described a portable journal turning lathe that could be readily transported in a disassembled state to a job site and then assembled quickly and easily onto a cylindrical pipe or shaft to be turned. 
     The journal turning lathe described in the &#39;093 patent comprises a pair of split clamshell assemblies that are held in parallel, spaced relationship to one another by a plurality of spacer rods. Two of the spacer rods support a tool carrier assembly for axial movement relative to a cylindrical shaft to be turned by the lathe. The tool carrier assembly includes at least one, but preferably two, cutting tool advancing mechanisms for controlling the radial placements of the cutting tools. The tool carrier assembly therefore controls the depth of the cut. The tool carrier assembly is arranged to be axially driven by threaded lead screw having a star wheel thereon which rotates the lead screw through a predetermined angle upon each rotation of the clamshell&#39;s movable ring member. The lead screw operates with a quick-release nut in the tool carrier assembly to permit rapid return of the tool carrier assembly to a home position upon completion of a pass. 
     The lathe in the &#39;093 patent is not readily configured to machine a tapered work piece. The slide plate in the &#39;093 patent is radially adjustable but not axially adjustable. Because the stabilizer brackets 26 are not capable of axial adjustment, if the work piece 12 were tapered, the tool carrier 44 can not be in contact with the work piece as the diameter of the work piece gradually decreases. 
     Likewise, U.S. Pat. No. 6,901,828, assigned to the applicant&#39;s assignee, is a journal turning lathe useful for machining a non-tapered work piece. The &#39;828 patent has a plurality of feed screws so as to hold the clamshell carrying the cutting tool square and concentric to a cylindrical work piece. The &#39;828 patent does not describe a means for axially adjusting the cutting tool to accommodate a tapered work piece. In fact, because the cutting tool is carried on an annular clamshell assembly 52 slidingly supported on guide shafts 42 and 44, the lathe is inherently incapable of machining a tapered work piece. 
     The journal turning lathe of the present invention obviates this drawback by providing a slide base capable of axial adjustment allowing the cutting head to be adjusted to the correct taper angle. 
     SUMMARY OF THE INVENTION 
     The foregoing features and advantages of the present invention are achieved by providing a tapered turning lathe for machining the outside surface of a tapered shaft. The tapered turning lathe comprises a drive housing and a support housing connected with a plurality of support shafts so as to be held in parallel, spaced relation to one another. The drive and support housings each have a plurality of threaded locators, which are used to hold and center the machine to the shaft. Both housings also support drive gear members which rotate on adjustable bearings held in the housing. A cutting head is moved by a feed screw and slides on two parallel shafts whose opposed ends are held in brackets that are radially adjustable, allowing the parallel shafts to be set parallel to the surface of a tapered work piece. 
     The cutting head contains a tool block which holds a tool bit. The tool block is affixed to the cutting head by at least two adjustable gibs. The tool block height can be adjusted by turning a tool bit adjustment screw for setting the depth of cut. 
     The threaded lead screw carries a traveling nut that is operatively coupled to the cutting head, whereby rotation of the lead screw causes longitudinal displacement of the cutting head along the two parallel shafts that are inclined at the same angle that the work piece is tapered. At least one tripper can be bolted to the drive housing. The trippers are used to push a cam, which is coupled through a one-way clutch to the lead screw to advance the cutting head in the axial direction a predetermined distance determined by the thread pitch or the lead screw. A feed knob is operatively coupled to the clutch whereby when the feed knob is pushed down, the clutch is engaged allowing the cutting head to be driven; but when the feed knob is pulled up, the clutch is disengaged and the feed screw can be rotated manually to return the cutting head to a home position. 
     A first radially adjustable slide plate is affixed to and rotates with the drive gear of the drive housing. Turning a height adjustment screw of the slide plate allows the parallel shafts carrying the cutting head to be adjusted to the correct taper angle. The support housing end of the tapered turning lathe supports the opposite end of the alignment shafts and the feed screw. A second radially adjustable slide plate is bolted to the drive gear face of the support housing. A bracket slide slides inside the slide base and is held in position with a second height adjustment screw. A pair of axial adjustment brackets is coupled to an end bracket, which supports the opposite ends of the parallel alignment shafts and the feed screw. The axial adjustment brackets allow axial adjustment of the cutting head. 
     The drive housing gear is rotated by a motor bolted to the drive housing. A coupling shaft is operatively coupled through a first gear train at a first end to the drive housing drive gear and through a second gear train at a second end to the support housing drive gear. The rotation of the drive housing drive gear is thereby translated to the support housing drive gear. By turning the drive gears on both ends of the tapered turning lathe, the cutting head alignment shafts will stay parallel to the center line of the work piece. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed descriptions of a preferred embodiment, especially when considered in connection with the accompanying drawings in which: 
         FIG. 1  is a perspective view of the tapered turning lathe of the present invention; 
         FIG. 2A  is an exploded view of the tapered turning lathe of  FIG. 1 , showing the first drive bracket assembly, and the drive housing bracket assembly; 
         FIG. 2B  is an exploded view of the tapered turning lathe of  FIG. 1 , showing the cutting head assembly, and the drive screw; 
         FIG. 2C  is an exploded view of the tapered turning lathe of  FIG. 1 , showing the second drive bracket assembly, and the support housing bracket assembly; 
         FIG. 3  is a top perspective view of the first drive bracket assembly of the tapered turning lathe of  FIG. 1 ; and 
         FIG. 4  is a perspective view of the second drive bracket assembly of the tapered turning lathe of  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to  FIG. 1 , there is indicated generally by numeral  10  a tapered journal turning lathe constructed in accordance with the present invention. It is adapted to be mounted on a tapered work piece  12  having a first end  14  and a second end  16 . Because the work piece  12  is tapered, the diameter of the work piece  12  gradually decreases from the first end  14  to the second end  16 . 
     The journal turning lathe  10  is seen to comprise an annular drive housing  18  and an annular support housing  20  each having an inside diameter large enough to surround the tapered work piece  12  to be turned. The drive housing  18  and support housing  20  are connected by four support shafts  22   a - 22   d . Formed radially through the thickness dimensions of both the drive housing  18  and the support housing  20  at intervals are equally radially spaced threaded bores, as at  24 , into which there is threadily fitted a plurality of threaded locator screws  26  which are used to hold and center the lathe  10  to the tapered work piece  12 . A cutting head assembly  28  is translated along a pair of parallel guide shafts  30   a - 30   b  between the drive housing  18  and the support housing  20 . 
       FIGS. 2A-2C  collectively show an exploded view of the journal turning lathe  10 . In  FIG. 2A  the drive housing  18  is a first annular member supporting a drive gear  32  journaled for rotation with respect to the drive housing  18 . The drive gear  32  includes drive gear teeth  34 , said drive gear  32  is journaled for rotation on the drive housing by adjustable bearings  36  that extend in the axial direction from the flat side surface of the drive housing  18  to fit into an annular groove formed inward from a side surface of the drive gear  32 . The drive gear  32  is adapted to be driven by a suitable motor  35  ( FIG. 1 ), such as a pneumatic, hydraulic or electric motor. The motor is mounted in the motor mount position  40  of the drive housing  18 . 
       FIG. 2C  shows that the support housing  20  is a second annular member supporting an annular driven gear  42  journaled for rotation with respect to the support housing  20 . The driven gear  42  is identical to the drive gear  32  in that it is journaled for rotation on bearings (not shown) that extend in an axial direction from the flat side surface of the support housing  20 . 
     As the drive gear  32  is rotated by the motor  35 , the drive gear  32  turns a series of idler gears journaled in the drive housing  18 . More particularly, the teeth  34  of the drive gear  32  mesh with a first spur gear  46  and rotates the first spur gear  46  on the axis of a first idler shaft  88   a . The first spur gear  46  also meshes with a second spur gear  48 , that rotates on the axis of a second idler shaft  88   b . The second spur gear  48  meshes with the coupling shaft collar gear  50 , rotating the coupling shaft collar gear  50 . A coupling shaft  52 , having a first end  54  and a second end  56  (shown in  FIG. 2C ), extends between the drive housing  18  and the support housing  20 . The first end  54  of the coupling shaft  52  is inserted into a center opening  51  of the coupling shaft collar gear  50 . Specifically a first collar  66   a  caps the first end  54  of the coupling shaft  52  and the first collar  66   a  is inserted into the opening  51  of the coupling shaft collar gear  50 . 
     A second collar  66   b  caps the second end  56  of the coupling shaft  52  and the second collar  66   b  is inserted into a second collar gear  58 . The second collar gear  58  is contained in the support housing  20 . The second collar gear  58  meshes with a first support housing idler gear  60  rotating on third idler shaft  88   c , and the first support housing idler gear  60  meshes with second support housing idler gear  62  rotating on fourth idler shaft  88   d.    
     A first and second front cover  64   a  and  64   b  each conceal the first and second collar  66   a  and  66   b . When the motor rotates the drive gear  32 , the drive gear  32  rotates the drive housing idler gears and the coupling shaft collar gears  50 . Rotation of the coupling shaft collar gear  50  rotates the coupling shaft  52 . When the coupling shaft  52  is rotated, the second collar gear  58  rotates in the support housing  20  turning the first support housing idler gear  60  and the second support housing idler gear  62 . The teeth  63  of the second support housing idler gear  62  mesh with the teeth (not shown) of driven gear  42 . By turning both the drive gear  32  and the driven gear  42  simultaneously the cutting head guide shafts  30  will stay aligned with the center line of the tapered work piece  12 . 
     A protective sheath  68  protects a worker from getting entangled in the coupling rod  52 . The coupling shaft  52  typically is hexagon-shaped in cross-section. 
     The drive housing  18  and the support housing  20  each have a plurality ( 4 ) of support shaft guides  70  extending radially from the housings. In the support shaft guide specifically referred to by numeral  72  on drive housing  18  there are a plurality of idler gear holes  74  where the driver housing idler gears are disposed. To facilitate rotation of the first and second spur gears  46 ,  48  in the idler gear holes  74 , a Timken cone  76   a  and a Timken cup  76   b  fit between the first and second spur gears  46 ,  48  and the rear cover  90 . A Timken cup bearing  78  is disposed behind the coupling shaft collar gear  50  in the idler gear slots  74 . The corresponding arrangement is found in a shaft guide  80  of the support housing  20 . In both arrangements a lock nut  86   b  and lock washer  86   a  prevent the Timken cup bearing  78  from falling out of the backside of the idler gear openings  74 . Likewise a hex jam nut  82  couples the spur gears to idler shafts  88  on which the spur gears rotate. A rear cover  90  bolts the idler gears into the support shaft guide, and is secured by hex clamp collar  91 . 
     The cutting head assembly  28  ( FIG. 1 ) comprises a cutting head  92  and tool bit adapter  94  (tool bit not shown in  FIG. 2   b ) adjustable secured thereto. A pair of guide shaft bores  96  extend axially through the cutting head  92 , along with a feed screw bore  98 . Guide bushings  100  encircle each guide shaft  30 . The guide bushings  100  are inserted into the guide shaft bores  96  and are sealed in the cutting head  92  by elastomeric seal members  102 . Seal members are placed on each end of the guide bushings  100  to seal the bushings  100  in the cutting head  92 , preventing lubricants and metal debris from entering the cutting head. The bushings  100  ensure smooth translation of the cutting head  92  along the guide shafts  30 . 
     The cutting head  92  also contains a tool block  104  which holds the tool bit. The tool block  104  is held to the cutting head  92  by adjustable gibs  106 . The tool block  104  and adjustable gibs  106  are inserted into the tool block slot  108 , said tool block slot  108  extends through the cutting head  92  perpendicular to the guide shaft bores  96  and feed screw bore  98 . A tool bit adjustment screw assembly is used to adjust the height of the tool block  104 . 
     The tool bit adjustment screw assembly comprises a dial member  112  operatively coupled to a tool block feed screw  114  such that rotation of the dial member  112  rotates the tool block feed screw  114 . A tool block feed nut  116  runs along the tool block feed screw and is operatively coupled to the tool block  104  so that rotation of the tool block feed screw  114  results in vertical translation of the tool block  104 . A feed screw bracket  118  is secured to the top surface of the cutting head  92  and the tool block feed screw  114  is journaled by a feed screw bushing  120  disposed in a center opening  122  of the feed screw bracket  118 . 
     The cutting head  92  is translated along the guide shafts  30  by a threaded lead screw  124  which extends between a radially adjustable drive bracket  126  mounted on the drive housing  18  and a radially adjustable support bracket  128  mounted on the support housing  20 . The threaded lead screw  124  has a first end  130  coupled to the drive bracket  126  and a second end  132  coupled to the support bracket  128 . The cutting head  92  is carried along the feed screw  124  by feed nut  134  operatively coupled to the feed screw  124 . As shown in  FIG. 2B , the feed nut  134  comprises an internally threaded tube member  134   a  surrounding the feed screw  124  and with an annular flange  134   b  formed at one end of the tube member  134   a . The tube member  134   a  has an inner surface (not shown) with threads cooperating with the threads of the feed screw  124  to carry the feed nut  134  along the feed screw  124 . The tube member  134   a  is inserted in the feed screw bore  98  of the cutting head  92 . The annular flange  134   b  is then secured to the wall of the cutting head  92  by feed nut fasteners  134   c.    
     With particular attention directed to  FIGS. 2A and 3 , a cam arm assembly is disposed in the cam arm assembly aperture  137  of the drive bracket  126  to effect rotation of the feed screw  124  in a manner yet to be described. One or more trippers  136  are bolted to the stationary drive housing  18  as at tripper slot  137  on the circumference of the drive housing  18 . The trippers  136  cooperate with cam assembly as it orbits about the work piece  12  which then turns the feed screw  124  and advances the cutting head  92  in the axial direction. 
     The cam assembly comprises a cam arm  140  having a one-way clutch engaging a gear train which rotates the feed screw  124 . The one-way clutch includes a roller clutch member  142  embedded in the cam arm  140 . The roller clutch member  142  is coupled to a clutch shaft  144  so that rotation of the clutch member  142 , in turn, rotates the clutch shaft  144 . A clutch shaft bushing  152  reduces friction between the clutch shaft  144  and the roller clutch member  142 . 
     The cam arm  140  is housed in a mount housing comprising a mount bracket  154  and a mount cover  156 . The mount bracket  154  has a slot in one side which the cam arm  140  extends out of and an aperture in the bottom for the clutch shaft  144  to pass through into the cam arm assembly aperture  137 . A spring  158  extends between a second sidewall of the mount bracket  154  and the cam arm  140  so that the cam arm  140  is made to return to its original position after the cam arm passes by a tripper  136 . A first and second mount bearing  160   a  and  160   b  sandwich the cam arm  140  to reduce friction when the cam arm  140  rotates in the mount bracket  154  and the mount cover  156 . 
     A gear train shaft  146  is coupled to the clutch shaft  144  so that the rotation of the cam arm  140  rotates the gear train shaft  146  inside the drive bracket  126 . A gear shaft helical gear  148  is coupled to the gear train shaft  146  at an end opposite of where the gear train shaft  146  is coupled to the clutch shaft  144 . A gear shaft bushing  150  is coupled to the gear train shaft  146  below the gear shaft helical gear  148  to reduce friction between the gear train shaft  146  and the drive bracket  126 . 
     A feed screw drive gear  162  is coupled to the first end  130  of the feed screw  124  inside the drive bracket  126 . The gear shaft helical gear  148  meshes with the feed screw drive gear  162  so that rotation of the cam arm assembly rotates the feed screw drive gear  162 , thus incrementally rotating the feed screw  124  advancing the cutting head. The feed screw drive gear  162  is affixed to the feed screw  124  by flex lock nut  164 . The first end  30  of the feed screw  124  is inserted into the drive bracket  126  at a drive housing feed screw aperture  166  which is perpendicular to the cam arm assembly aperture  137 . A Timken cone  168   a  and Timken cup  168   b  facilitate rotation by reducing friction between the first end  130  of the feed screw  124  and the drive bracket  126  in the drive housing feed screw aperture  166 . An oil seal is disposed proximate the Timken cone  168   b  to prevent lubricant from escaping out of the drive housing feed screw aperture  166 . The drive housing feed screw aperture  166  is closed off at one end by a feed screw seal cover  172  and a feed screw access cover  175  at the other. 
     A feed knob  174  is provided for reciprocally engaged or disengaging the clutch. The clutch shaft  144  has first end  145  with a hexagon shape that engages the feed knob  174 . Specifically, the underside (not shown) of the feed knob  174  has an octagon recess that mates with the first end  145  of the clutch shaft  144 . When the feed knob  174  is pushed down the clutch is engaged so that the drive gear  32  rotates past a tripper  136 , the cam arm  140  is deflected, turning the gears  148 ,  162  located in the drive bracket  126 , which causes the feed screw  124  to turn. Conversely, when the feed knob  174  is pulled up, the feed knob  174  is released from the clutch shaft  144 , disengaging the one-way clutch  142 . The feed screw  124  can then be rotated manually by turning the gear train shaft  146 . 
     The drive bracket  126  has a first and second side bracket  177   a  and  177   b  ( FIG. 3 ) bolted to opposed side surfaces  127   a ,  127   b  thereof. Each side surface  127   a ,  127   b  has a pair of spaced apart bolt apertures  178  each adapted to receive side bracket fasteners  180 . The side brackets  177   a  and  177   b  have corresponding spaced-apart fastener apertures  182   a  and  182   b  for receiving the side bracket fasteners  180 . The top fastener aperture  182   a  is arcuate shaped and the bottom fastener aperture  182   b  is circular. The side bracket fasteners  180  then secure the side brackets  177   a  and  177   b  to the drive bracket  126  by having them inserted into the bolt apertures  178  through the corresponding fastener apertures  182   a  and  182   b . Because the bottom fastener apertures  182   b  are circular and the top fastener aperture  182   a  is arcuate shaped, the drive bracket  126  can pivot along the axis of the bottom fastener apertures  182   b , but the degree of pivot angle is limited by the length of the arcuate shaped top fastener aperture  182   a.    
     Each side bracket  176   a ,  176   b  is fastened to a drive bracket slide member  184 . The drive bracket slide member  184  is a generally rectangular plate having a top  186   a , a bottom  186   b  and two sides  186   c ,  186   d . The top  186   a  has a bracket groove  188  cut into it. The drive bracket slide  184  slides inside the confines of a drive bracket slide base  190 . 
     The drive bracket slide base  190  is a rectangular plate having a first and second flange  192   a ,  192   b  projecting perpendicularly from the two ends of the plate. A slide gib  194  abuts the first flange  192   a  and the drive bracket slide  184  slides along the slide gib  194 . Turning the height adjustment screw  196  ( FIG. 3 ) located on the drive bracket slide  184  moves the drive bracket slide  184  up and down the slide gib  194 . The height adjustment screw  196  is a feed screw with a drive bracket feed nut  198  coupled to slide base  190 . A slide plate feed screw bracket  200  is fastened into the bracket groove  188 , and the height adjustment screw  196  passes through and is held by a central aperture  202 . A feed screw bushing  204  reduces friction between the height adjustment screw  196  and the slide plate feed screw bracket  200 . A dial  206  is used to turn the height adjustment screw  196 . When the height adjustment screw  196  is rotated the drive bracket feed nut  198  slides the slide plate along the slide base  190 , allowing the guide rods  30  supporting the cutting head  92  to be adjusted to the correct angle of the taper of the tapered work piece  12 . 
     Turning now to  FIG. 4 , the end bracket  128  supports the opposite ends of the guide shafts  30  and the second end  132  ( FIG. 2   c ) of the feed screw  124 . The end bracket has guide shaft bores  216  into which the opposite ends of the support shafts  30  are inserted. The second end  132  of the feed screw  124  is inserted into the feed screw bore  218  in the end bracket  128 . The second end  132  of the feed screw  124  is held in the support feed screw bore  218  by the feed screw bushing  220 . The support bracket  128  is generally block-shaped with two side ends  222   a  and  222   b.    
     A support housing slide base  208  is bolted to the annular driven gear  42  of the support housing  20 . The support housing slide base  208  is a generally rectangular plate having a bracket groove  224  cut into the top portion  226  and two flange members  228   a  and  228   b  extending outward from the opposite ends of the base  208 . The first flange  228   a  extends at approximately a 90° angle from the base  208 . The second flange  228   b  also extends from the bracket slide  210  at an angle of 90°, but also forms a v-cut between the base  208  and the end of the flange  228   b.    
     A support housing slide member  210  slides inside the support housing slide base  208  and is held in position by height adjustment screw  212 . The support housing bracket slide  210  is a generally rectangular plate having a front side and a back side, and a first and second end. A support slide gib  234  is disposed between the first flange  228   a  of the base plate  208  and the first end  232   a  of the slide  210 , and the slide plate  210  slides in the slide gib  234 . Because the second flange  228   b  integrally forms a gib, the slide  210  slides in the slide base  208 . 
     The support housing height adjustment screw  212  is identical in construction to the height adjustment screw  196  of the drive bracket slide  184 , and can be understood to work in an identical fashion. 
     Bolted to the opposed side surface of support bracket  128  are two axial adjustment brackets  235 . Each axial adjustment bracket  235  has a top arcuate shaped aperture  240  in spaced-apart relation to a bottom arcuate shaped aperture  242 . Two parallel, spaced-apart flanges  244  project from the front side  236  of the axial adjustment bracket  234 . A support aperture  246  is disposed between the parallel, spaced-apart flanges  244 . 
     The axial adjustment brackets  235  are coupled to the support bracket  128  and hold the support bracket to the support housing bracket slide  210 . Axial adjustment fasteners  248  pass through the top and bottom aperture  240 ,  242  and are secured to the support bracket  128  by fastener bores  250  disposed in spaced-apart relation to each other on the ends  222   a ,  222   b  of the support bracket  128 . A support side bracket  252  is fastened to the axial adjustment bracket  235  between the parallel flanges  244  by passing a support side fastener  248  through the support side bracket aperture  256  and into the support aperture  246 . The support side bracket  252  is fastened to the support housing bracket slide  210 . 
     Bolted or otherwise affixed to the drive gear  32  is a first stabilizer bracket  264 . A second stabilizer bracket  266  is affixed to the driven gear  42 . Fitted into axially extending bores (not shown in drawings) in the first stabilizer bracket  264  and into corresponding bores formed in the second stabilizer bracket  266  are three parallel, spaced-apart stabilizer rods  272 . The stabilizer rods  272  along with stabilizer brackets  264 ,  266  not only function to maintain rigidity between the housings  18  and  22 , but also function as a counterweight for the mass of the guide shafts  30 , and feed screw  124  and cutting head assembly  12 . 
     OPERATION 
     Having described the mechanical configuration of the tapered journal turning lathe  10  of the present invention, consideration will next be given to its mode of operation. 
     The workman will arrive at the job site with the journal turning lathe assembly disassembled into several subassemblies. The various subassemblies are assembled about the tapered work piece  12  to be turned as illustrated in  FIG. 1 . The drive housing  18  and support housing  20  will be positioned and adjusted so that they are both coaxially disposed with the axis of the work piece  12 . 
     The workman will then adjust the angle of the guide shafts  30  to follow the taper of the work piece  12  using the height adjustment screws  196  and  212  to raise and lower the ends of the guide rods  30 . The cutting head  92  is then positioned to the desired location along the guide shafts  30  using the feed nut mechanism in its non-engaged state. Once the starting point for the cut is set, the feed knob  174  will be pushed down so as to cause the clutch  142  to engage the clutch shaft  144  and cause the feed screw to turn only when the tripper assembly  136  is engaged. Next, the workman will adjust the depth-of-cut of the tool bit using dial member  112  for rotating the tool bit adjustment screw assembly to affect displacement of the tool block  104 . 
     The drive motor (not shown) meshed to the drive gear  32  will then be turned on to rotate the drive gear ring  32  as well as the drive bracket  126 , support bracket  128 , the guide shafts  30  and the cutting head assembly  28  mounted thereon. Diametrically disposed relative to the foregoing assembly is the counterweight assembly including stabilizer brackets  264  and  266 , and the stabilizer rods  272 . Each rotation will cause the tool bit to remove a layer of metal from the work piece  12 . Also, at various points in the revolution of the assembly, the cam arm  140  will be engaged by tripper  136  causing the feed screw  124  to rotate advancing the cutting head assembly  28  along the length of the work piece  12 . 
     In particular, engagement of the cam arm  140  will also rotate the gear shaft helical gear  148  which meshes with the feed screw drive gear  162  to rotate the feed screw  124 , thus advancing the cutting head  92  in an axial direction. 
     This invention has been described herein in considerable detail order to comply with the Patent Statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components. However, the invention can be carried out by specifically different equipment and devices. Various modifications, both as to the equipment details and operating procedures, can be accomplished without departing from the scope of the invention itself.