End prep facing machine

A portable end prep facer for refurbishing piping components in the field comprises a chuck to which a cylindrical mandrel is affixed where the chuck can be centrally mounted relative to a longitudinal axis of the piping component by affixing the chuck either to the I.D. or the O.D. of the piping component. A non-rotatable torque housing surrounds the mandrel and is longitudinally positionable there along. A cutting head assembly is journaled for rotation about the mandrel by means of bearings mounted in the torque housing and coapting with an annular race formed in a face plate of the cutting head assembly. Mounted on the face plate is a variable speed reversing drive mechanism that couples to a lead screw that forms a part of a tool support guide member. A sliding head is affixed to the lead screw and it, in turn, supports a tool bit holder that can be manually adjusted to set the depth of cut when machining the flange portion of a piping component being repaired.

BACKGROUND OF THE INVENTION 
I. Field of the Invention 
This invention relates generally to portable, on-site metal machining 
equipment, and more particularly to an apparatus that can be mounted on a 
piping component for machining a surface of that component. 
II. Discussion of the Prior Art 
Oil refineries, chemical processing plants, pipeline companies and power 
plants typically provide fluid handling through piping systems where 
adjacent piping components are connected together by running bolts through 
mating flanges thereof. Such piping components may include straight pipe 
sections, elbows, nozzles, reducers, valves, etc. These components are 
typically subjected to fluids under high pressure, high temperatures, 
adverse atmospheric conditions, and having corrosive properties. Over 
time, such piping components may develop leaks due to scoring, warpage, 
and metal erosion, especially on flange faces. When this happens, it is 
necessary to machine the flange faces to remove grooves due to scoring and 
to restore a true flat surface to the flange meeting the original 
specifications for the pipe segments. Flanges on large diameter pipes also 
will include an annular groove having tapered side walls for receiving a 
metal seal ring therein. These grooves are also subject to wear and 
periodically need to be machined to insure seal integrity. Flanged pipes 
may also require internal diameter boring and outside diameter turning 
operations in the filed. 
When it is considered that in many industrial installations, the piping 
components may vary anywhere from about 30 inches to 120 inches in 
diameter and may weigh several tons, it is impractical to transport such 
pipe components to a machine shop facility for refurbishment. Accordingly, 
a need exists for a machine for refacing flanges of piping components in 
the field. 
In the Hunt Patent, U.S. Pat. No. 4,852,435, there is disclosed a portable 
machining tool for refacing or regrooving pipe flanges. It comprises a 
chuck that is adapted to be mounted within the bore of the pipe component 
to be refurbished. The chuck supports a machine body that is motor driven 
so as to rotate about an axis that is aligned with the center of the 
chuck. Mounted on the machine body is a tool bar that is fed in a 
direction transverse to the longitudinal axis of the pipe in which the 
chuck is mounted and it carries a cutting tool for engaging the surface of 
the flange being refaced so as to remove metal as the tool bar is being 
fed across the face of the flange. 
Another portable flange facer adapted for use in the field is available 
from the Climax Machine Tool Company of Newberg, Oreg., and which is more 
particularly described in the Strait Patent, U.S. Pat. No. 5,630,346. With 
reference to that patent, its tool bar 200 feeds radially in and out. This 
presents a problem when working in confined spaces. More importantly, the 
feed system depicted in FIGS. 4, 5 and 6 of the '346 patent does not 
provide continuous feed. Instead, the feed stops and starts with each 
actuation of the cams 100A and 100B on the rocker arms 152A and 152B. This 
tends to leave an uneven surface finish. Such a condition is not 
acceptable in certain flange sealing applications. 
The prior art devices suffer from a number of other drawbacks that limit 
its capabilities. For example, in the Strait '346 patent, the tool base 
234 cannot swivel and, hence, the cutting tool 254 cannot be used for 
cutting angled grooves when desired. 
It is sometimes advantageous to mount the chuck to the inside diameter of 
the pipe component whose flange is to be refaced. In other applications, 
it is advantageous to affix the chuck to the perimeter of the flange 
itself. No provision is made in the prior art for allowing one or the 
other of these two mounting modes. The device described in the Hunt '435 
patent suffers from a number of operational deficiencies. First of all, 
there are no mitering capabilities in the chuck assembly, making setup and 
centering somewhat difficult. Moreover, there is no provision for 
translating the rotatable main body 70 relative to the spindle 10. In 
terms of performance, the feed resulting from the use of the feed cam 94 
on the cam follower 96 results in an inferior surface finish due to the 
inherent lurching involved. Further, there is no provision in the Hunt 
machine for adjustment of the rotational bearing 72 following a period of 
use and resulting wear. Furthermore, it is not possible to reverse the 
feed direction without first removing and reversing the position of the 
feed slave unit 110. 
It is, therefore, desirable to have an end prep facer for refurbishing 
piping components that obviates the aforementioned problems inherent in 
prior art machines used for this purpose. 
SUMMARY OF THE INVENTION 
In accordance with a first feature of the present invention, there is 
provided an end prep facer for refurbishing piping components that 
comprises a chuck having a plurality of equally spaced, radially extending 
legs of adjustable length that are adapted to support the chuck at a 
center point of a tubular piping component to be refurbished. A 
cylindrical mandrel of a predetermined outer diameter is affixed to the 
chuck with a miter connection that allows limited skewing of the mandrel 
relative to the chuck at the time of setup. The end prep facer further 
comprises a torque housing having a cylindrical tube with an inner 
diameter slightly greater than the predetermined outer diameter of the 
mandrel and the cylindrical tube of the torque housing is mounted in 
concentric relation on the mandrel for longitudinal displacement there 
along. The torque housing has a radial flange portion and a plurality of 
cylindrical, longitudinal bores are formed in a face of the flange portion 
at uniformly spaced circumferential intervals proximate the periphery of 
the flange portion to accommodate the insertion of roller bearings in 
those bores. A first ring gear is affixed to the face of the flange 
portion and is concentric with the aforementioned cylindrical tube. A 
manually operable feed screw is operatively coupled between the mandrel 
and the torque housing so as to allow adjustment of the position of the 
torque housing along the longitudinal axis of the mandrel. A cutting head 
assembly having an annular face plate with first and second major surfaces 
is also disposed about the mandrel and is supported by the roller bearings 
affixed to the flange portion of the torque housing. More particularly, 
the annular face plate of the cutting head assembly has an annular bearing 
race formed in the first major surface thereof for engaging the roller 
bearings of the torque housing. A second ring gear which is concentrically 
mounted with respect to the bearing race is also secured to the first 
major surface of the annular face plate. Affixed to the second major 
surface of the face plate is a right angled drive device having a drive 
gear that meshes with the first ring gear and whose output shaft is 
coupled to an input shaft of a variable speed gear box assembly bolted to 
the second major surface of the face plate. The variable speed gear box, 
in turn, has an output shaft that drives a reversing differential gear 
box. A drive motor, either electric or hydraulic, is mounted on the torque 
housing such that a driving gear on that motor's output shaft engages the 
second ring gear for rotating the cutting head assembly relative to the 
torque housing assembly about the mandrel as a center. Finally, there is 
affixed to the second major surface of the annular face plate of the 
cutting head assembly a tool support guide member that has a lead screw 
mounted thereon. The lead screw is operatively coupled so as to be driven 
by the output shaft of the reversing differential gear box. Affixed to the 
lead screw is a sliding head member that is movable therewith in a 
direction transverse to the longitudinal axis of the mandrel. The sliding 
head member supports a tool bit holder capable of being swiveled relative 
to the sliding head member and which can be manually actuated to establish 
the depth of cut of a tool bit relative to the surface being refaced.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Certain terminology will be used in the following description for 
convenience in reference only and will not be limiting. The words 
"upwardly", "downwardly", "rightwardly" and "leftwardly" will refer to 
directions in the drawings to which reference is made. The words 
"inwardly" and "outwardly" will refer to directions toward and away from, 
respectively, the geometric center of the device and associated parts 
thereof. Said terminology will include the words above specifically 
mentioned, derivatives thereof and words of similar import. 
In FIG. 1, there is indicated generally by numeral 10 an end prep facer 
comprising a preferred embodiment of the present invention. It is shown as 
being mounted within the I.D. of a pipe component 12 having a flange 14 
with a flange face surface 16 to be refurbished. As will be further 
explained below, it is possible to mount the machine to the O.D. of a pipe 
flange, as well. The end prep facer 10 is shown in FIG. 1 as 
concentrically mounted within the internal diameter of the pipe component 
12 by means of a chuck 18 (FIG. 3) having an octagonal peripheral surface. 
Bolted to each of the eight faces is a leg assembly 20 that extends in the 
radial direction to engage I.D. of the pipe component 12. With reference 
to FIG. 3, each of the legs 20 comprises an extension block member 22 
having a tubular stem portion 24 whose internal bore 26 is sized to 
receive a tubular bushing 28. The length of the bushing 28 is selected to 
accommodate pipe components 12 of various sizes and may, for example, come 
in 5 inch increments up to 15 inches in length. Fitted into the extension 
bushing 28 is a locator screw bushing 30 having a threaded internal 
diameter into which a threaded locator screw 32 may be screwed. Thus, as 
can be seen in FIG. 1, when all eight leg assemblies 20 are affixed to the 
eight facets of the chuck 18, the locator screws 32 projecting out from 
the ends of the locator bushings 30 can be adjusted so as to center the 
chuck 18 relative to the I.D. of the pipe component 12 to be machined. 
As seen in FIG. 3, the front face 34 of the chuck 18 is generally planar 
but includes an arcuate circular groove 36 therein and a plurality of 
threaded bores 38 are found in the face of the chuck into which threaded 
studs 40 are screwed. A front miter plate 42 has a plurality of regular 
spaced bores corresponding in number and spacing to the bores 38 formed in 
the face 34 of the chuck. Each of the bores 44 is countersunk, as at 46, 
with a spherical depression for receiving therein spherical washers, as at 
48, the spherical washers being placed over the ends of the studs 40 
projecting through the front miter plate. Nuts, as at 50, secure the front 
miter plate to the face of the chuck. 
Not visible in the view of FIG. 3 is an annular projection having a rounded 
contour conforming to the contour of the arcuate groove 36 formed in the 
chuck's face 34. Using this mounting arrangement, the front miter plate 
can be tipped or tilted relative to the planar surface of the chuck by 
selective tightening and loosening of the nuts 50 on their respective 
studs. The purpose of this miter coupling will be explained in greater 
detail as the description of the preferred embodiment continues. 
In certain applications encountered in the field, a plurality of tubular 
pipes may terminate in a common flange and in these installations, the end 
prep machine of the present invention cannot be mounted to the I.D.'s of 
the individual pipes. There is, therefore, provided a mounting kit for 
affixing the end prep facer of the present invention to an outside 
diameter, and this kit is more particularly illustrated in FIG. 4 of the 
drawings. It comprises a support bracket 21 comprising a weldment of a 
base plate 23 having a pair of intersecting steel channels 25 and 27 
attached to it for strength. Welded to the exterior of the bottom portions 
of the channels 25 and 27 at each end thereof is a rectangular solid 
block, as at 29, having a circular bore 31 formed therethrough into which 
may be fitted an extension tube 33 whose length is dependent upon the size 
of the flange surface to be refurbished. Affixed to the outer ends of the 
extension tubes 33 are mounting arms 35. Each of the four mounting arms 
includes a connector portion 37 in the form of a rectangular block and 
having a bore 39 formed thereon so that it can be slipped over the end of 
the tube 33 before bolts 41 are tightened to firmly clamp the block 37 to 
the extension tube 33. The mounting arms extend over the exterior edges of 
the flange on which the facer is to be mounted and a further plate (not 
shown) may be temporarily connected by welding or bolting to join the 
mounting arm to the reverse side of the flange to be refurbished. 
A center shaft 43 which is threaded at each end fits through a longitudinal 
bore in the mount support bracket and through a central opening of a 
swivel plate 45 and then into the threaded central bore 47 of a rear miter 
plate 49. The central opening in the support bracket 21 and the swivel 
plate 45 are larger in diameter than the O.D. of the center shaft 43, 
allowing the support bracket and swivel plate to be tilted about the 
center shaft 43 as an axis. 
Located at 90.degree. intervals along the edge of the plate 23 are ears 51 
having a threaded bore through the thickness dimension thereof. Set screws 
(not shown) are threaded through the ears 51 so as to cooperate with 
rectangular tabs 53 welded to the swivel plate 45. By selective adjustment 
of the set-screws (not shown), the swivel plate 45 can be shifted 
laterally over a limited range relative to the support bracket 21, to aid 
in centering. 
Welded to the rear surface of the swivel plate 45 at 90.degree. intervals 
are stub shafts 55 which extend perpendicularly to the center line of the 
shaft 43 when assembled through the support bracket 21, the swivel plate 
45 and threaded into the miter plate 49. Cooperating with the stub shafts 
55 are adjustable couplers indicated generally by numeral 57. The 
adjustable couplers include a self-aligning bearing 59 that are pressfit 
into rod end members 61 having a right-hand thread thereon that receives 
an adjustment nut 63 thereon. Also threaded into the adjustment nut 63 is 
a lefthand adjustment screw 65. A screw bracket 67 has a threaded bore for 
mating with the left-hand thread adjustment screw 65. The adjustable 
coupler thus acts like a turn-buckle. 
Referring next to FIG. 2, the end prep facer of the present invention is 
seen to comprise a smooth, polished cylindrical mandrel 52 which passes 
through the central opening of an annular torque housing member 54. As 
will be explained in greater detail, the torque housing member 54 can be 
made to slide longitudinally relative to the mandrel 52, but is prevented 
from rotating about the mandrel as an axis. Bolted to the torque housing 
is a drive motor 56. The drive motor may be electric or hydraulic and it 
has an output shaft with a spur gear mounted on it where the spur gear 
engages an outer ring gear 58 that is mounted to the underside of a 
faceplate 60. A shroud or cover forming a part of the bearing housing 
assembly 62 is bolted to the face plate 60 and is also concentrically 
mounted with respect to the mandrel 52. 
Referring simultaneously to FIGS. 3, 5 and 6, when an I.D. mount is used, 
the front miter plate 42 is bolted to an end face 64 of the mandrel 52 by 
bolts not shown passing through bores 66 formed through the miter plate 42 
and into threaded bores 68 formed inward of the end face 64 of the mandrel 
52. It is apparent, then, that with the miter plate 42 assembled to the 
chuck and with the mandrel 52 bolted to the miter plate 42, the 
cylindrical mandrel 52 becomes a stationary member. The torque housing is 
longitudinally adjustable relative to the mandrel but it is nonrotatable 
with respect to it. As will, be explained in greater detail, the face 
plate 60 comprising a part of the bearing housing assembly can be shifted 
longitudinally with the torque housing and is also able to rotate about 
the mandrel as a center when driven by the drive motor 56 and its 
engagement with the outer driving ring gear 58. 
Referring to the exploded view of FIG. 6, the construction of the torque 
housing assembly will be explained. The torque housing assembly includes 
the torque housing member 54 which, as seen in FIG. 1, comprises a 
cylindrical portion 70 having a truncated annular conic cap 72 defining a 
central opening through which the mandrel 52 extends. The cylindrical 
portion 70 of the torque housing extends outwardly from an exposed face of 
an annular flange 74 and a series of gussets 76 placed at 90.degree. 
intervals are used to provide additional structural rigidity to the torque 
housing members 54. 
With continued reference to FIGS. 5 and 6, there is seen on the interface 
78 of the flange 74 a series of radially spaced bores 80 that extend 
around the periphery of the flange 74. Fitted into each of the bores 80 is 
an eccentric bushing 82 on to which is affixed a roller bearing 84. These 
roller bearings are adapted to cooperate with an annular race in the form 
of a groove 86 formed inward of the underside of the face plate 60. The 
width of the annular groove 86 forming the bearing race is wider than the 
diameter of the bearing 84 and the eccentric bushings 82 on alternate 
bearing assemblies are adjusted to cause alternate bearings to ride 
against the opposite annular walls of the bearing race 86. A threaded 
aperture 88 (FIG. 5), adapted to be closed by a threaded cap 90, overlays 
the annular race 86. By removing the cap 90, an operator may view bearing 
adjustment and operation during assembly. The eccentric bushings 82 may be 
adjusted so that the bearings 84 will continue to engage the walls of the 
race 86 following prolonged use and wear through the access ports 81 
formed in the torque housing 54. 
An inner ring gear 92 is also concentrically disposed about the cylindrical 
portion 70 of the torque housing and is bolted to the inner face thereof. 
The outer ring gear 58 is fastened to the undersurface of the face plate 
60 and extends around the periphery thereof by fasteners not shown passing 
through drilled openings 94 and into an upper flat surface of the ring 
gear. Semicircular shields 96 and 98 enclose the side surfaces of the 
outer ring gear to prevent entry of foreign objects, such as metal chips 
between the gear's teeth. 
With the I.D. mount of FIG. 3 being used, to longitudinally displace the 
torque housing 54 relative to the mandrel 52, there is provided a threaded 
shaft 100 whose head 102 is affixed by screws (not shown) to the rightmost 
end of the mandrel 52. A rear bearing housing plate 72 slides over the 
shaft 100 and bolts to the back face of the torque housing 54 by means of 
bolts (not shown) passing through the drilled bores 106 of the rear 
bearing plate 72. Fitted over the shaft 100 is a first thrust bearing 108 
and threaded on to the shaft is a nut 110. A second thrust bearing 112 
helps to minimize longitudinal thrust of the threaded shaft 100. An 
annular feed bearing cap 114 bolts to the rear bearing plate 72. A hand 
wheel 116 has an integrally formed annular collar 119 secured to the nut 
110 so that rotation of the hand wheel 116 will result in rotation of nut 
110 and its movement along the threaded shaft 100 carries the torque 
housing longitudinally along the surface of the mandrel 52. To prevent 
rotation of the torque housing 54, four keys 118 are placed at 90.degree. 
intervals in slots 120 formed in the mandrel. The keys 118 also engage 
slots (not shown) formed in the inner wall of the cylindrical portion 70 
of the torque housing 54. To assist in rotation of the hand wheel 116, 
four handles, each comprising a shaft 121 and a spherical knob 122, screw 
into the peripheral edge of the hand wheel 116, again at 90.degree. 
intervals. 
When the O.D. mount kit shown in FIG. 4 is to be used to support the end 
prep facing machine relative to the work piece, the components evenly 
numbered between 100-122 are not used, but instead, the rear miter plate 
49 of the O.D. mounting kit shown in FIG. 4 is bolted to the mandrel 52 
while the screw brackets 67 attach to pad areas 69 (FIG. 1) on the rear 
portion of the torque housing 54, shown in FIG. 6. Thus, by selective 
adjustment of the nut 63 and the set screws (not shown) threaded through 
the ears 51 and cooperating with the tabs 53 on the swivel plate 45, the 
torque housing assembly, including the mandrel, can be appropriately 
squared to the piping component to be refurbished. 
With reference now to FIG. 7, mounted atop the face plate 60 is the drive 
assembly for translating the cutting tool across the face of the flange 
being repaired as the face plate 60 and the bearing housing assembly 62 
are made to rotate about the mandrel 52. The drive assembly is indicated 
generally by numeral 124 and includes the face plate 60 to which the outer 
ring gear 58 is attached. Secured to the opposite side of the face plate 
from the ring gear 58 is a right angle drive assembly 126, a variable 
speed gear box 128, a reversing differential gear box 130 and the guide 
and drive mechanism 132 for the sliding tool head 134. 
The bearing housing 62 of FIG. 5 is shown in greater detail in the exploded 
perspective view of FIG. 8. It is seen to comprise a cylinder having a top 
plate 135, an annular side wall 137 and a radially extending flange 139 
projecting outwardly at the base of the wall 137. A plurality of radially 
spaced bores 141 are provided in the flange, allowing bolts to pass 
therethrough for securing the bearing housing assembly 62 to the upper 
surface of the face plate 60. The top plate 135 has a central opening 143 
formed therethrough, allowing the mandrel 52 to extend through it. 
Extending around the central opening 143 at regularly spaced intervals are 
rectangular sockets, as at 145, and formed completely through the 
thickness of the top plate in each of the rectangular sockets is a 
circular opening 147 into which a Hepco.TM. bearing 149 is adapted to fit. 
The shaft of the bearings 149 mount in adjacent plates 151 that are 
dimensioned to fit into the rectangular sockets 145 and to be bolted in 
place. Thus, it can be seen that the bearings 149 project downward into 
the interior of the cover. The bearings cooperate with a spindle bearing 
race 153 that is dimensioned to fit around the periphery of the mandrel 
and has an outer peripheral surface shaped to conform to the V-groove on 
the peripheral face of the Hepco bearings 149. Thus, the bearing race 153 
is captured by the bearings 149 and, along with the bearings 84 on the 
torque housing, journal the cutting head assembly for rotation about the 
mandrel as an axis. The bearings 149 are fully adjustable in and out to 
prevent chattering between those bearings and the spindle bearing race 153 
following a period of use and wear. 
The right angle drive assembly 126 has a shaft extending through an opening 
in the face plate 60 and affixed to that shaft is a spur gear that is 
arranged to mesh with the inner drive ring gear 92 that is affixed to the 
stationary torque housing 54. As the face plate 60 is driven by the drive 
motor 56, the spur gear on the right angle drive assembly rotates to drive 
the output shaft 136 which is coupled by a universal joint to an input 
shaft 138 of the variable speed gear box 128. 
The variable speed gear box used in the preferred embodiment is 
commercially available from Zero Max, Inc. of Minneapolis, Minn., but 
limitation to that particular device is not intended. That device 
functions to vary the speed of its output shaft from 0 rpm to 400 rpm, 
depending upon the positioning of a control handle. Referring to FIG. 10, 
the output shaft of the variable speed gear box 128 has a spur gear 140 
affixed to it for mating with a similar spur gear 142 affixed to an input 
shaft of the reversing differential gear box 130. A control arm 144 
connects to a control shaft (not shown) on the Zero Max, Inc. variable 
speed gear box and pivoting of this control arm either increases or 
decreases the speed of rotation of the spur gear 140, depending upon the 
direction of movement of the control arm. 
With momentary reference back to FIG. 5, a control shaft 144 having a pull 
knob 146 affixed to its outer end extends through the bearing housing 
assembly 62 to connect to adjustable length linkage 148 and 149 that is 
pivotally coupled to the control arm 144. Thus, an operator, by pulling or 
pushing on the knob 146, may govern the speed at which the input shaft of 
the reversing differential gear box 130 is driven. 
An exploded view of the right angle drive assembly 126 is illustrated in 
FIG. 9. It has an idler shaft 150 that is journaled for rotation in sealed 
bearings 152 disposed in a bearing housing member 154 and the spur gear 
156 that mates with the inner ring gear 92 attaches to the lower end of 
the idler shaft 150. The bearing housing 154 fits into a recess formed in 
the face plate 60 and it includes a rectangular socket 158 into which fits 
a gear box base member 160. The gear box base 160 is designed to contain 
sealed bearings 162 which are used to journal the input shaft 164 of the 
right angle gear box 126. A bevel gear 166 is attached to the upper end of 
the input shaft 164 and when the gear box top member 168 is bolted to the 
gear box base 160, the bevel gear 166 is disposed within the top member 
168 to mesh with a second bevel gear 170 affixed to the output shaft 172 
of the right angle gear box. The output shaft is journaled for rotation in 
the gear box top member 168 by means of a bearing cup 174 and an 
associated bearing cone member 176. The far end of the output shaft 172 is 
journaled in the gear box top member 168 by sleeve bearings 178. The input 
shaft 164 is driven by a spur gear 180 that attaches to the lower end of 
the input shaft 164 projecting out through the bottom of the gear box base 
160 and through an aperture formed in the rectangular socket 158 to mesh 
with the spur gear 156 being driven by the inner ring gear 92. The 
universal joint coupler 182 for connecting the output shaft 172 of the 
right angle gear box 126 to the input shaft 138 of the variable speed gear 
box 128 is also seen in FIG. 9. 
The details of construction of the reversing differential gear box 130 can 
be seen in the exploded perspective view of FIG. 11. It comprises a 
housing 184 having an input shaft 186 journaled for rotation therein by 
bearings 188 and 190, bearing 190 fitting into an annular collar 192 on a 
cover plate 194. The spur gear 142 that meshes with the spur gear 140 on 
the output shaft of the variable speed gear box 128 is affixed to the end 
of the output shaft 186 and a bevel or miter gear 196 is affixed to its 
opposite end. 
Extending through the reversing differential gear box housing 184 
transverse to the output shaft 186 is a reversing shaft 198 that is 
journaled in the housing by means of bearing sets 200 and 202. A pair of 
oppositely directed miter gears 204 and 206 are journaled for rotation on 
the reversing shaft 198 by means of needle bearing sets 208 and 210. The 
miter gears 204 and 206 at all times mesh and rotate with the miter gear 
196 on the input shaft 186. 
Keyed to the reversing shaft 198 so as to be slidable longitudinally there 
along is a reversing clutch member 212. The clutch member 212 has an 
annular, centrally located groove 214 into which the tines of a shifting 
fork 216 are adapted to fit. A cylindrical stem 218 of the tuning fork 
fits through a bore (not shown) formed in the rear side of the reversing 
differential gear box housing 184 and can be maneuvered by an operator to 
displace the reversing clutch member 212 along the reversing shaft 198. In 
operation, as the miter gear 196 drives the clutch gears 204 and 206, one 
of the gears 204 or 206 will move with a clockwise rotation while the 
other of the gears 204 and 206 will rotate in a counterclockwise 
direction. Thus, by manipulating the shifting fork 216 to slide the 
reversing clutch member 212 in a first direction against one of the gears 
204 or 206 that is rotating clockwise, the reversing shaft 198 will also 
rotate in a clockwise direction. When the shifting fork is manipulated to 
bring the reversing clutch member 212 into contact with the other of the 
two bevel gears, the shaft 198 will be made to rotate in the 
counterclockwise direction. A spur gear 220 is attached to the end of the 
reversing shaft 198 and is adapted to mesh with a spur gear 222 on a shaft 
224 (FIG. 12) of a feed screw gear box 226 forming a part of the guide and 
drive mechanism 132 for the sliding tool head 134. 
With continued reference to FIG. 12, the shaft 224 is journaled for 
rotation by bushings 228 and 230 that are disposed in the left hand gear 
box half 232 and the right hand gear box half 234, respectively. A hubless 
gear 236 is affixed to the shaft 224 and is designed to mesh with a hex 
pinion gear 238. Referring to both FIGS. 12 and 14, an elongated shaft of 
hexagonal cross-section 240 passes through the right-hand gear box half 
234 and through a first bushing 242, a further bushing 244 having a 
hexagonal central opening and through the hex pinion gear 238 and thence 
through a further bushing 246 so as to extend out through the bore 248 
formed through the lefthand gear box half 232. Thus, rotation of the 
hubless gear 236 on the shaft 224 results in rotation of the hex shaft 240 
by virtue of the engagement between the hubless gear 236 and the hex 
pinion gear 238. 
Referring again to FIG. 7, the hex rod 240 forms a part of a feed screw 
assembly 250 which is depicted in the exploded perspective in FIG. 14. The 
hex shaft 240 is journaled by the bushings 242, 244 and 246 in the gear 
box comprised of the halves 232 and 234, but is also supported along its 
length by virtue of being journaled in a feed screw bearing housing 252. 
More particularly, and with reference to FIG. 14, a sliding head feed 
screw 254 has a stub 256 of reduced diameter at the lefthand end thereof, 
a portion of which is threaded to receive a lock nut 258 thereon. Disposed 
on the unthreaded portion of the stub 256, in going from right to left, is 
a thrust washer 260, a thrust bearing 262 and a further thrust washer 264. 
After passing through the opening in the feed screw bearing housing 252, a 
further thrust washer 266, a thrust bearing 268, another thrust washer 270 
and a lock washer are assembled onto the stub 256 before the lock nut 258 
is affixed. 
A tubular feed nut 274 is externally threaded to mate with internal threads 
within a feed nut tube 276. The feed nut tube 276 has a transversely 
extending rectangular flange 278 that is adapted to be bolted to the 
sliding tool head 134 as shown in FIG. 7. The feed nut 274 is also 
internally threaded to mate with the external threads on the feed screw 
254. As the hex rod 240 is driven, it carries the sliding head feed screw 
254 with it causing the feed nut 274 to move along its threaded exterior 
and, in doing so, the feed nut carries the sliding tool head 134 with it. 
FIG. 13 provides an exploded perspective view of the guide portion of the 
guide and drive mechanism 132 of FIG. 7. It is seen to comprise an 
elongated casting of generally rectangular cross-section that serves as a 
linear bearing housing 280. Depending upon the size of the piping 
component to be refaced or machined, a linear bearing housing extender 282 
may be joined end-to-end with the housing half 280 by means of coupling 
bushings 284 which fit into cylindrical bores 286 and 288 formed both in 
the linear bearing housing 280 and in the mating extension 282. A pair of 
guide shafts 290 and 292 fit within the elongated bores 286 and 288 and 
are slidably supported in those bores by three sets of linear bearings 
that are spaced apart from one another by intermediate tubular spacers. A 
first set of linear bearings is identified by numeral 294 and a second set 
by numeral 296 with intermediate spacers 298 and 300. A third set of 
linear bearings 302 also fit into the bearing housings 280 and are 
separated from the bearing set 296 by tubular spacers 304. 
As seen in FIG. 7, the free ends of the guide shafts 290 and 292 attach to 
the tool slide head 134. The details of construction of the tool slide 
head are illustrated in the exploded perspective view of FIG. 15. The 
sliding head assembly 134 comprises a head member 306 having a pair of 
parallel bores 308 and 310 for receiving the ends of the guide rods 292 
and 290, respectively, therein. Screws (not shown) are inserted into 
threaded bores as at 312 and 314 to secure the head 306 to the guide rods. 
Depending upon the size of the piping component being worked on, an 
optional sliding head extension member 316 may be used to provide 
additional stability to the sliding tool head 306. The sliding head 
extension 316 is adapted to be bolted to the beveled surface 318 of the 
sliding head member 306 and linear bearings 320 and 322 are provided for 
providing smooth sliding engagement with an outboard support shaft 324 
(FIG. 7). The cylindrical shaft 324 includes a base portion 326 that gets 
bolted to the face plate 60 and which enters a guideway slot 328 formed in 
the extension member 316. 
The tool block 330 has a channel 332 formed therein for receiving a tool 
bit (not shown). The tool bit is clamped in place in the channel when a 
cap plate 334 is bolted on to the tool block. A gear rack fits into a 
further channel 338 on the rear side of the tool block 330 and its teeth 
are arranged to mesh with pinion gear teeth 340 ground on the end of a 
pinion stem member 342. The pinion stem fits through a bushing 344 that 
fits into an aperture 346 formed centrally in a swivel head member 348 and 
through the central opening of a swivel head base member 350 to which the 
swivel head 348 is bolted. The tool block 330 is arranged to slide up and 
down with respect to the swivel head member 348. More particularly, first 
and second gibs 352 and 354 are slidingly received within opposed side 
channels 356 formed in the tool block 332 and the gibs, in turn, are 
fastened to the swivel head member 348. When the pinion stem 342 is 
rotated, it cooperates with the rack teeth on member 336 to raise and 
lower the tool block 332 relative to the swivel head member 348, depending 
upon the direction of rotation of the pinion stem 342. 
The pinion stem 342 has a pinion gear 358 keyed to the end thereof and the 
gear 358 along with the swivel head base 350 are adapted to fit within a 
cavity 360 formed in the face of the sliding head member 306. A pair of 
swivel head keeper plates 362 and 364 capture the swivel head base 350 
within the cavity 360 when the keeper plates are bolted to the sliding 
head member 306. When the screws holding the keeper plates to the sliding 
head member are somewhat loose, it is possible to swivel or rotate the 
tool block 330 and the swivel head 348 to which it is affixed to a desired 
angular orientation before the screws holding the keeper plates to the 
sliding head member 306 are tightened so as to clamp and hold that desired 
angular position. By providing the ability to both swivel and translate 
the tool block 330, the device of the present invention is capable of 
performing O.D. turning, flange face grooving, beveling or boring. 
The sliding head block 306 includes a further cylindrical bore (not shown) 
therethrough in which a tool block feed shaft 366 is journaled for 
rotation. The shaft is journaled in a pair of bushings 368 and 370 and a 
pinion gear 372 is affixed to an end thereof for meshing with the pinion 
gear 358 affixed to the pinion stem member 342. The tool block feed shaft 
366 is adapted to be rotated through a universal joint 374 that couples 
the tool block feed shaft 366 to an extension shaft 376. 
It can be seen from the foregoing description of the preferred embodiment 
that the end prep facer of the present invention can be mounted either to 
the I.D. or O.D. of a pipe component whose flange is to be machined and 
because of the adjustability features built into the mounting kits (FIGS. 
3 and 4). The mounting chuck can be readily centered with respect to the 
longitudinal axis of the pipe component. Once the chuck is so positioned, 
a crane or forklift may be used to move the cutting head assembly of FIG. 
5 on to the chuck with the threaded studs 40 extending through the front 
miter plate 42. By selective adjustment of the mounting bolts 50, the 
miter plate 42 can be skewed appropriately so that the cutting tool 
disposed in the tool block 332 of FIG. 15 will traverse a locus of points 
in a plane generally parallel to the surface of the flange of the piping 
component to be refurbished. Then, by rotation of the hand wheel 120, a 
course adjustment of the tool bit can be made to bring it into close 
proximity to the flange. 
Now, by energizing the drive motor 56, the face plate 60 and bearing 
housing 62 bolted thereto will rotate about the mandrel or spindle 52 as a 
center. As the face plate rotates, the spur gear 156 on the right angle 
drive assembly 126 will mate with the rotating inner ring gear 92 and thus 
will be driven. As previously described, the speed of rotation of the 
output shaft of the right angle drive 126 can be multiplied by the 
variable speed gear box 128 and, further, the direction of rotation of the 
lead screw 250 can be set by selective manipulation of the shifting fork 
216 forming a part of the reversing gear box 130. 
This causes the sliding tool head 134 to move in or out depending upon the 
direction of rotation of the lead screw 250. Manual adjustment of the 
shaft 376 (FIG. 15) may move the tool bit against the flange surface. As 
the tool block and cutting tool traverse the flange, metal is removed 
therefrom and periodically the operator may further rotate the shaft 376 
to thereby translate the tool block 332 relative to the swivel head 348 
and, in doing so, adjust the depth of cut for the next pass. 
This invention has been described herein in considerable detail in 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 as are required. However, it is to be 
understood that the invention can be carried out by specifically different 
equipment and devices, and that various modifications, both as to the 
equipment and operating procedures, can be accomplished without departing 
from the scope of the invention itself.