US3230668A

US3230668A - Interior surface pipe grinding and cleaning machine

Info

Publication number: US3230668A
Application number: US339750A
Authority: US
Inventors: Stanley Richard Carl
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-01-23
Filing date: 1964-01-23
Publication date: 1966-01-25
Anticipated expiration: 1983-01-25

Description

Jan. 25, 1966 R. c. STANLEY INTERIOR SURFACE PIPE GRINDINGAND CLEANING MACHINE Jan. 25, 1966` R. c. STANLEY INTERIOR SURFACE PIPE GRINDING AND CLEANING MACHINE Jan. 25, 1966 R. c. STANLEY INTERIOR SURFACE PIPE GRINDING AND CLEANING MACHINE Filed Jan. 25, 1964 4 Sheets-Sheet 3 INVENTOR. /f//Ae 52m/L fr BY M Arme/v5 Ys.

Jan. 25, 1966 ZZO R. c. STANLEY 3,230,668

INTERIOR SURFACE PIPE GRINDING AND CLEANING MACHINE Filed Jan. 23, 1964 4 Sheets-Sheet 4 g NI, INVENTOR,

N/ ///Ae SMA/fr H BY fr M M. I f Armen/EVS.

United States Patent O 3,230,668 INTERIOR SURFACE PIPE GRINDING AND CLEANING MACHINE Richard Carl Stanley, 2602 S. 11th St., Gadsden, Ala. Filed Jan. 23, 1964, Ser. No. 339,750 11 Claims. (Cl. 551-5) This invention relates to improvements in pipe cleaning machines, and more particularly to a machine adapted to improve the internal surface of a pipe by grinding with abrasive coated belts powered by driven pressure wheels which orbit about the pipe axis so that a helical grinding pattern is generated as t-he self propelled machine proceeds through the pipe. The pitch angle of the helical grinding pattern is a function of the number of pressure wheels used and the width of abrasive belt. As the grinding operation proceeds through a pipe, compressed air is injected ahead of the grinding belt to remove all accumulated dirt, grit and scale material. n

The fluid flow characteristics of large diameter pipes such as used in pipe lines are influenced to a large degree by the interior surface roughness of the pipe line. To improve this situation, many pipe line owners are coating the interior of their pipes with various types of palnts or resins, a number of different methods being employed to prepare the interior surface of the pipe line to receive the paint. Most of these methods fail by a wide margin. Some methods even aggravate the above problem by leaving surface whiskers or splinters projecting from the internal surface of the pipe line.

T-he instant invention solves the above problems economically and efficiently by multiple grinding, cleaning 'and removing scale, burrs, dirt and grit from the pipe line without the additional expense of coating the interior o-f the pipe line.

A primary object of this invention is to provide a new internal surface pipe grinding and cleaning machine for improving the -surface of a pipe line.

Another object of the invention is to provide a machine for helically grinding and cleaning the internal surface of a pipe line.

A further object of the invention is to provide an improved powered abrasive belt grinding means for the internal surface of a pipe line which orbits the longitudinal axis of the pipe so that a helical grinding pattern is generated as the machine proceeds through the pipe line.

A still further object of the invention i-s to provide an improved self-propelling means for an internal pipe grinding and cleaning machine.

Another object of the invention is to provide an improved means including power rotated pressure wheels which force an abrasive belt against the internal pipe surface and cause it -to grind and clean the same.

A further object of the invention is to provide counterweight to eliminate the effect of centrifugal forces and gravity forces lof orbiting belt grinders includ-ing spring iactuated or pneumatic cylinder actuated idler roller to tension the grinding belt so as to maintain a uniform grinding pressure on all points of the internal circumferential surface of the pipe line as the novel machine travels forward and backward through the same.

A still further object of the invention is to provide an electrically driven mechanism adapted to allow passage of compressed air to remove grinding residue.

Another object of the invention is to provide a powered nonorbiting wire brush adapted to improve the internal cleaning action of an internal longitudinal weld bead of a pipe l-ine.

Another object of the invention is to provide an improved internal surface pipe grinding machine provided with hinged linkage means between the components of 3,230,668 Patented Jan. 25, 1966 "ice the machine to follow the internal surface contour of a curved pipe line.

A further object of the invention is to provide an irnproved internal surface pipe grind-ing machine adapted to be adjusted to various internal sizes of pipe lines. l

A still further object of this invention is to provide a new internal pipe surface grinding and cleaning machine including manually controlled electrical energy means adapted to selectively self propel the machine forwardly and backwardly in a pipe line during internal grinding and cleaning of the same.

The nature of the invention and its further advantages and features of novelty will become apparent to those skilled in the art from the following detailed description and discussions of the exemplary embodiment of the invention shown in the accompanying drawings wherein:

FIGURE la is a fragmentary view in elevation of the rear self-propelling portion of the machine connected to the intermediate portion or grinding motor cage of the machine, certain hidden parts and a pipe line in which lthe machine is operating being shown in dotted lines;

FIGURE 1b is a fragmentary sectional view in elevation of the machine taken at the forward end of the grin-ding motor carriage showing lthe power take-off shaft, adjustable support rollers, rotary compressed air supply means surrounding the power take-olf shaft including drive means connecting the power take-off shaft to a nonorbiting cleaning brush adapted to clean the internal welded seam of a p-ipe line, shown in dotted line-s; p

FIGURE lc is a fragmentary sectional view in elevation of the front :end of the machine of the instant invention connected to its intermediate portion to illustrate the rotary universal joint and power shaft take-01T connections between the grinding belt head iand the front end of the supporting carriage and the rotary belt and pulley take-off of the propelling shaft from the grinding motor, the shaft serving as a rotating conduit for the air supply and a dispensing nozzle therefor secured to the belt head, the pipe line and certain hidden parts being shown lin dotted lines;

FIGURE 2a is a top plan view of FIGURE 1a;

FIGURE 2b is a top plan View of FIGURE lb;

FIGURE 3 is a transverse sectional view taken substantially on line 3 3 of FIGURE la in the direction of the arrows;

FIGURE 4 is a cross-sectional View of the rotary compressed `air supply gland connected to the tubular propelling shaft of FIGURE lb;

FIGURE 5 is la transverse sectional View of FIGURE lb taken substantially on line 5 5 in the direction of the arrows;

FIGURE 6 is a transverse sectional view of FIGURE lb taken substantially on line 6 6 in the direction of the arrows;

FIGURE 7 is a front end elevational view of FIG- URE lc;

FIGURE 8 is an enlarged fragmentary sectional view in elevation of the rotating belt head and driven roller means, spring tensioned idlers of the abrasive belt including an actuating counterweight therefor connected to the belt head secured to a rotating carrier tube which concentrically surrounds the tubular propelling tube energized by the grinding motor; and

FIGURE 9 is a partial sectional view of FIGURE 8 taken substantially on line 9 9 in the direction of the arrows.

Referring more specifically to the drawings, in which like reference numerals represent like parts, FIGURES la, 2a and 3 disclose the rear end of an exemplary embodiment of the new machine showing the propulsion unit mechanism 20 comprised of substantially triangular side support frame members 21 and 22 having a pair of bottom angles 2 3 and a top bar means 24 welded or suitably secured therebetween.

Bottom angles 23 support gear and cone drive means 25 by bolts 26.

A propelling motor 27 is supportably connected by screw bolts 28 to the back plate portion 29 of drive means 25.

A plate 30 includes a lug 31welded or suitably attached thereto and is secured by screw bolts 32 to the back portion 'of the housing of motor 27. A manually operated handle or boom 33 is pivotally secured by clevis 34 and bolt 35 to lug 31. Handle 33 is telescopingly secured to extension rod 34a of clevis 34 by screw bolt 36. Handle 33 terminates in ahand grip 37 to which is centrally attached to an electrical Control box 38 having

control buttons

39 and 40 for electrically energizing, by cable 41 motor 37 for forward and backward travel of the machine respectively in a pipe line. electrically energize, by cable 45, grinding motor 46 in casing or carriage 48. Control box 38 is energized by elec-` trical cable 47.

Propulsion wheel 50 is mounted in a rubber tire 51 of desired type to frictionally contact the inside surface of a pipe line 52 shown in broken lines in FIGURES la, 2a and 3. Propulsion wheel 50 is suitably mounted on axle 53 which is mounted in bearing54 vo f structural side 21by a nut and washer 56 and l58, respectively. Propulsion wheel 50 is secured to sprocket 49 by bolt 55.

Gear box 25 is operatively connected by shaft 60 and nut 62 to sprocket 63.

Sprocket 49 is driven by belt or chain means 65 connected to sprocket 63 to drive propulsion wheel 50.

An end plate 61 of carriage 48 has an apertured coupling lug 64 welded or suitably attached thereto and is secured by bolt 66 to motor casing 48.

Propulsion unit 20 is pivotally secured by screw bolt 68 and bar 24 to lug 64 of plate 61.

The plate 61 carries an additional apertured lug 70 which -is pivotally connected by a bolt 72 to roller block 74 comprising side members 75 and 76and Lcross member 77 welded ,or suitably connected together. Cross member 77 threadably carries screw '78 which adjustably contacts face plate 61 to pivot -block 74 about bolt 72.

Block 74 carries in suitable bearing bolt 80 which serves as an axle for roller 82 which contact the sides of pipe line `52h and serve -as a guiding means for the back portion of the pipe grinding `and cleaning machine.

FIGURES 1b, 2b, 4, 5 and 6 disclose an intermediate portion of the new machine. A flange 82a interiorly of the grinding motor carriage 48 is secured by bolt 84 to the grinding motor 46.

Carriage 48 `extends as Va circularsection 86 and flat-offset section or deck 88. Carriage portion 86 houses a gear box 89.

Gearbox 89'is suitaby securedby-pivoted bracket 83 and adjustment screw 83a to the circular side portion .of-housing 86 as best shown in FIGURE '7. Gear box 89'carries shaft 90 mounted in bearings 1 91-and 921. Afsuitable clutch 94, of a commercial type, is xed by a spline and key o r other suitable means to shaft'90. The outer portion 96 of clutch 94 is integrally attached to sprocket 98 rotatably carried on shaft 90. Shaft 90 carries pulley 100 secured thereto by set screw or other suitable means.

Shaft 102-of motor 46 xedly carries pulley 103 thereon. Pulley 103 drives pulley 100 by belt 104. Sprocket 98 drives by timing belt 101 sprocket 104a carried by shaft 106. Shaft 106 is rotatably supported in bearings 108 and 110..of gear housing 89, as best shown in FIGURE 2b.

Shaft 106, shown in broken lines of FIGURE 2b iixedly carries at one end a universal joint 112 connected to shaft 113 further connected to universal joint 114 secured to shaft llsupported by bearing 120 kin side carrier tube 118. The-outer end of shaft 116 has vsecured thereto sprocket 122 byset screw 124.

Motor shaft 102, of FIGURE lb, is connected by uni- Control push button or switch .43 may be used to versal joint 126 yand intermediate shaft 127 to universal joint 128 connected to tubular propelling shaft 130.

Propelling shaft 130 rotatably carries compressed air supply joint and gland 132 attached to a supply conduit 133 as hereinafter explained in connection with FIG- URE 4.

Propelling shaft 130 xedly carries pulley 134 which drives pulley 136 by belt 137, as shown in FIGURE 1b. Pulley 136, of FIGURES lb and 2b, is secured by set screw or other suitable means to shaft 138 of gear box drive means 139 of a conventional type.

Gear box drive 139 carries a transverse shaft 140 securely connected to pulley 141 which drives at a desired ratio of rotation a pulley 142, carried on shaft 156, by belt 143. An abrasive roller or brush 158 is fixedly secured to shaft 156 by screw or other desired means.

Gear box drive 139 is mounted on base 144 secured by screw bolt 146 to flat deck portion 88 of housing 86 as best seen in FIGURES lb and 2b.

The flat deck portion 88 xedly supports by welding an upstanding bracket 148 pivotally connected by rivet 149 to bracket 150 secured by side support members 152 and 153 and bearing 154 surrounding shaft 156 carrying intermediate its ends pipe seam abras-ive roller or brush cleaning 158 for cleaning the longitudinal welded seam of pipe line 52. Tensioning on belt 143 is adjusted by screw 160Q between brackets 148 and 150, yas best shown in FIGURES 1b and 2b.

The front end 88a of motor housing 48 pivotally supports roller guiding side block 160 which pivotally carries by bolts 161 side roller 162 which contacts the internal side surfaces of pipe line 52. Block 160 is secured internally by welded intermediate bar 163 and is further pivotally connected by bolt 164 to lug 1565 welded to housing 88. Roller 162 are laterally adjusted by screw and bolt 165a for Contact with the internal side surfaces of pipe line 52, as best shown in FIGURES 2b and 5.

Referring more specifically to FIGURE 4, compressed air rotary gland 132 is comprised generally, of gland housing body 170, bearing 171, spacer 173, nut 173a, packing 174, sealing 175, packing gland 176, tubular shaft 177 secured on shaft 13.0 by collar 178, set screw 179, and O-ring seal 130. Gland body fhas an intermediate supply connection 172 adaptedto be connected to the compressed air supply hose 133 shown -in FIGURE lb.

Gland body 170 is longitudinally secured on tubular shaft 177 by spring-like snap ring y 182 in recess 181 of tubular shaft 177.

Body member 170 has a recess 184 communicating with compressed air supply connection 172 and aperture 186 communicating with the hollow air conduit 187 of power shaft 130.

For servicing ofpacking 174 and seal175, body mem-A ber 170 is secured by recessed steps 188 to end body mem-V ber 190 by screw bolt 192 as shown in `FIGURE 4.

Referring more specifically to FIGURES lb and 5, cage 88a is secured to lug 194 by bolt 195. Lug 194 is secured by bolt 196 to roller block 197 comprising crossbar 198 shown in broken lines welded to lateralside members 199. Pulley block 197 carries support roller 200by bolt 202.

Dead .arde l203 is fixedly secured by Welding to end housing 88a. Dead axle 203 supports internally propelling tubular shaft 130 `by bearing 204, radial support elements 204a `being provided to assist in carrying de ad axle 203.

Dead axle 203 has xed or welded thereto ring 205 which is further secured by bolt 206 to collar and ring ange 207. Flange 207 is secured at its lower portion to lug 208 to toggle bolt 210 which is in `turn pivotally secured to bolt 211 of block 199 to adjust supporting pulley 200 to contact the various bottom internal surfaces of different sizes of pipe line 52.

As seen'in FGURES 1b and lc, seal 212 mounted in housing 218aY surrounds the end circumferential portion of collar 207 to seal a bearing 214 in hub 215. The upper race portion of bearing 214 is pressed or suitably secured into central hub 215 secured to carrier tube 216.

Sprocket 217 is suitably yattached by bolt 218 to hub 215.

Sprocket 122 (FIGURE 2b) by a suitable chain (not shown) drives sprocket 217 to rotate carrier tube 216 carrying belt yhead 220 to generate a spiral grinding pattern on the internal surface of pipe line 52 as will be hereinafter explained.

Referring to FIGURES lc, 7, 8 and 9, housing 215e is secured by bolts 218e to central hub 215 as best seen in FIGURE 1c. Housing 215e encloses seal 212, as shown.

FIGURE lc shows an extension of propelling tube 130, concentric dead axle 203 and rotary concentric carrier tube 216 connected to belt grinding head 220 and belt and pulley housing 222 connected by a driving universal joint and shaft to abrasive belt grinding head 220, as hereinafter explained in detail.

Referring to FIGURES 8 and 9, abrasive belt grinding head 220 is comprised of a central segmented spider 224 fabricated by welded plate and structural shapes of a suitable metal material welded to rotary carrier tube 216. Each segmented spider 224 is comprised of Iplates 230 and angles 231.

Platesy 230 each support four rollers 232 by standoff collar 234 :and eccentric bolt 237. Each plate 230 has welded thereto apertured lug 238.

Each energized or powered roller 240 and 240:1 is rotatably supported by a shaft 242 in bearing 243 in a U-shaped member 244 pivotally secured at the forward end to side angle 246 by pivot bearing 248.

U-shaped member 244 is longitudinally adjusted by screw 249 :and block 250 through aperture 251 in angle 246. Each outward edge portion 245 of angle 246 is ground in a longitudinal V-shape 252 to fit the internal groove 253 of roller 232, as best seen in FIGURES 8 and 9.

Referring to FIGURE 8, the lower angle portion 246a of angle 246 is pivotally connected by bolt 254 to rigid ot`r`-set lever 255 pivotally connected by bolt 257 to lever 258 further pivotally connected by bolt 260 to lug 261 welded tocarrier tube 216. The off-set portion of lever 255 terminates in a screw bolt 262 welded or suitably fixed thereto which carries `a counterweight 263 held rigidly thereon by screw nut members 264.

Abrasive belt energizing rollers 240 and 240e carries abrasive belt 265 of a desired width.

The tension on abrasive belt 265 is automatically maintained by roller 266 mounted by bolt 267 in reciproeating roller block 268 mounted side guide angle 269 welded to carrier tube 216. Spring 270 is mounted between roller block 268 and carrier tube 216, as best shown in FIGURE 9. Spring 270 serves as a biasing means to force roller 266 against belt 265 to insure that belt 265 is alwaysproperly tensioned against powered rollers 240 `and 240e.

In use, grinding head 220 rotates with counterweight 263 and tube 216. Rollers 240 and 240:1 are heavy and their centrifugal for-ces during their planetary rotation tend to throw both of these rollers and the counterweight 263 radially outwardly simultaneously. The centrifugal force of counterweight 263 reacts on lever 255 about fulcrum bolt 257 tending to slide the mounting 252 of roller 240e radially inwardly to oppose the gravity and centrifugal forces due to the weight of the rollers and their mounting, which force is radially outwardly. By properly adjusting the Weight of counterweight 263, its centrifugal forces are sufiicient to smooth out or eliminate the damaging centrifugal and gravity forces of the orbiting belt grinding means during spiral grinding of the internal surfaces of pipe line 52 by the relative rotations of belt 265 about carrier tube 216.

Referring more specifically to FIGURES 1c and 7, belt and pulley housing 222 is secured by bolts 272 to double support ring 273 suitably fabricated from structural shapes and welded at point 274 to carrier tube 216 rotatably supported on dead axle 203 by bearing 275. End housing ring 276 is secured by bolts 277 to the front portion of structural double support ring 273 to enclose air sealing 278. Propelling tube 130 i-s supported in dead axle 203 by end bearing 280.

Propelling tube 130 xedly carries

pulleys

282 and 283 thereon and terminates in a rotary compressed air union 284 connected to a hose 285 connected to nozzle 286 secured in holder 287 welded to pulley and belt housing 222.

Double support ring 273 carries a tube 289 welded or suitably secured therein.

Tube 289 carries shaft means 290 and 291 in bearing 292, as best shown in FIGURE lc. Shafts 290 and 291 Carry pulleys 293 and 293e, ref spectively, on one end and universal joints 294 and 294e, respectively, on the other end thereof, as best shown in FIGURE lc.

Pulley 262 drives pulley 293a by belt 296.

Pulley 283 drives lpulley 293 by belt 298.

Shaft 290 drives abrasive roller 240 by

universal joints

294 and 297 and shaft 300.

Shaft 291 drives abrasive belt roller 240a by universal joints 294e and 302 and shaft 303.

During operation, air is supplied to dispensing nozzle 286 through rotary air supply joint 132, tubular propelling shaft 130, rotary air union 234 and hose 285 connected to dispensing nozzle 286 so that as pulley housing 222 is rotated by carrier tube 216 energized by sprocket 217, air nozzle 286 circumscribes the internal circumferential surfaces of pipe line 52 periodically as the inventive machine travels back and forth through the internal surfaces of the same.

During operation of the inventive machine, motor 27 energizes propul-sion wheel 50 through gear and cone drive 25,

sprocket

49 and 63 and chain 65 connected by sprocket 49 to traction wheel 50 to selectively propel the machine forwardly and backwardly through pipe line 52.

As the machine is propelled through pipe line 52, grinding motor 46 energizes rollers 240 and 24011 by propelling shaft and differential shaft 300 and 303. Cleaning brush 158 is rotated by pulley 134 on propelling shaft 130. Carrier tube 216 is energized by motor shaft 102, belt 104, gear box 89, differential shaft 113 connected to shaft 116 connected to sprocket 122 and by a belt (not shown) connected to sprocket 217 secured to rotary carrier tube 216 which rotates belt grinding head 220.

A particular novelty of the new ma-chine resides in its many cooperating modes of operation during internal travel through pipe line 52.

To cover the full interior surface of pipe line 52, belt grinding head 220 is energized by motor 46 to orbit or rotate about the pipe line axis While its belt rollers 240 and 240e are independently energized by propelling tube 130 and differential shafts 300 and 303, so that a helical grinding pattern is generated on the internal surface of the pipe line 52 as the machine proceeds through pipe line 52.

More specifically, abrasive belt grinding head 220 rotates with carrier tube 216 and sprocket 217 which is energized by motor shaft 102 connected by belt 104, gear box 89, shafts 113 and 120, and sprocket 122.

As grinding head 220 rotates with tubular carrier shaft 216, rollers 240 and 240e and abrasive belt 265 are energized by motor 46 and by propelling tubular shaft 130 carrying

pulleys

282 and 283 connected by

belts

296 and 298 to pulleys 293 and 29301, respectively, which energize rollers 240 and 240e by

universal joints

294 and 297 connected by shaft 300 and by universal joints 294e and 302 connected by shaft 303, respectively, as best shown in FIGURE 1c.

Belt and pulley housing 222 is secured to carrier tube 116 and rotates in concert therewith during passage of the inventive machine through pipe line S2.

In summary, the new machine of the present invention is reversing and self-propelling through control switches 33 and 39, cleans longitudinal seams in pipe line 52 by energized brush 158, radially grinds the internal circumferential pipe surfaces by abrasive belt 2.65 which is also `rotated with respect to the pipe line axis to generate a helical grinding pattern on the internal `surface of pipe line 52 to give a multiple cleaning and grinding eiect as air nozzle 286 and housing 222 is rotated in unison with carrier tube 216 and grinding belt head 220.

From the foregoing it will now be seen that there is herein provided an improved self-propelled pipe line grinding and cleaning machine which will internally follow the contour of a straight or uniformly curved pipe line and accomplishes all the objects of this invention, and others including many advantages of great practical utility and commer-cial importance.

Many and varied embodiments may be made of this inventive `concept :as obtained within the purview of this invention as desired by those skilled in the art without departing therefrom. Therefore, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

1. Apparatus for grinding and cleaning the interior surface of pipes comprising, in combination, a carriage, means for movably supporting said carriage interiorly of a pipe, a propulsion unit including a propulsive wheel adapted to engage a pipe interior, a motor carried by said propulsion unit for driving said wheel, means connecting said propulsion unit to said carriage at one end thereof, a second motor mounted on said carriage, a dead tubular axle extending from the other end of said carriage, a p-ower shaft universally connected to said second motor concentrically mounted for rotation interiorly of said dead axle, a carrier tube concentrically mounted for rotation exteriorly of said dead axle, a belt head connected to said carrier tube, rotatable about said dead axle, means connected to said second motor for rotating said carrier tube and hence said belt head', roller drivel shafts extending Ifrom said belt head, belt and pulley connections 4between said power shaft and said roller drive shafts i-n said belt head for rotating said drive shafts independently of the rotation of said belt head, plate means carried by lsaid carrier tube, -belt rollers supported by said plate means radially about said carrier tube, meansy connecting said drive shafts to said belt rollers, and an abrasive pipe cleaning Vbelt extending around said belt rollers and adapted to abrasively engage the interior of said pipe.

2. The structure of claim 1 wherein said means connecting said propulsion unit to said carriage comprise a pivotal connection permitting lateral pivotal movement of said carriage and propulsion unit relative to each other to facilitate the passage of the apparatus through uniformily curved pipes.

3. The structure of claim 2 wherein said means for introducing compressed air into said hollow shaft includes an air sealed gland surrounding said hollow power shaft adjacent its connection to said second moto-r, said hollow shaft being rotatable in said gland, said gland and hollow shaft having registering air openings therein and an air conduit extending to the interior of said gland.

4. The structure of claim 1 wherein said power shaft is hollow, means are included for introducing compressed air into said hollow shaft, and an air nozzle, connected to the hollow interior of said hollow shaft, is positioned on the outer surface of said belt head and rotatable with said belt head.

5. The structure of claim 1 wherein said means for movably supporting said carriage interiorly of a pipe include a support roller and adjusting screw means for varying the relative height of the apparatus in accordance with the diameter of the pipe in which it is adapted to operate.

6. The structure of claim 5 wherein said means for movably supporting said carriage interiorly of a pipe further include guiding side rollers and adjusting means for varying the relative position of said guiding side rollers to said carriage -to center the apparatus in a pipe.

7. The structure of claim 1 wherein said iirst motor is reversible, an elongated handle extends from the end of said propulsion means remote from said carriage, and control means for said rst and second motors are mounted on the extending end of said handle.

8. The structure of claim 7 wherein said elongated handle comprises a plurality of telescopic section-s and means for securing said sections in fixed relation to each other to vary the effective length of said handle.

9. The structure of claim 1 wherein said belt rollers include driven belt rollers and idler ybelt rollers and said plate means for supporting the belt rollers includes multiple guide means, support brackets for said belt rollers linearly adjustable in said guide means,- and independent spring biasing means mounted on the guide means of said idler rollers for maintaining tension in said abrasive belt.

1?. The structure of claim 9 wherein said driven rollers are connected by linkage to counterweigh-ts, to counteract centrifugal and gravitational forces.

1l. The structure of claim 1 wherein said carriage'includes a supporting bracket on-its upper side, an axle carried by said supporting bracket, a seam cleaning brush rotatably mounted on said axle and drive means connected to said power shaft `for rotating said brush.

References Cited by the Examiner UNlTED STATES PATENTS 2,305,107 12/1942 Premo 5l-142 X 2,742,259 4/1956 Boucher l5-l04.l2 X 3,004,278 10/1961 Stanley l5--l04-09 X ROBERT C. RIORDON, Primary Examiner.

J. SPENCER OVERHOLSER, LESTER M. SWINGLE,

Examiners.

Claims

1. APPARATUS FOR GRINDING AND CLEANING THE INTERIOR SURFACE OF PIPES COMPRISING, IN COMBINATION, A CARRIAGE, MEANS FOR MOVABLY SUPPORTING SAID CARRIAGE INTERIORLY OF A PIPE, A PROPULSION UNIT INCLUDING A PROPULSIVE WHEEL ADAPTED TO ENGAGE A PIPE INTERIOR, A MOTOR CARRIED BY SAID PROPULSION UNIT FOR DRIVING SAID WHEEL, MEANS CONNECTING SAID PROPULSION UNIT TO SAID CARRIAGE AT ONE END THEREOF, A SECOND MOTOR MOUNTED ON SAID CARRIAGE, A DEAD TUBULAR AXLE EXTENDING FROM THE OTHER END OF SAID CARRIAGE, A POWER SHAFT UNIVERSALLY CONNECTED TO SAID SECOND MOTOR CONCENTRICALLY MOUNTED FOR ROTATION INTERIORLY OF SAID DEAD AXLE, A CARRIER TUBE CONCENTRICALLY MOUNTED FOR ROTATION EXTERIORLY OF SAID DEAD AXLE, A BELT HEAD CONNECTED TO SAID CARRIER TUBE, ROTATABLE ABOUT SAID DEAD AXLE, MEANS CONNECTED TO SAID SECOND MOTOR FOR ROTATING SAID CARRIER TUBE AND HENCE SAID BELT HEAD, ROLLER DRIVE EXTENDING FROM SAID BELT HEAD, BELT AND PULLEY CONNECTIONS BETWEEN SAID POWER SHAFT