United States Patent [191
`Harris
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,815,201
`Mar. 28, 1989
`
`[54] TUBE TRAVELER DEVICE
`[75]
`Inventor: Richard T. Harris, Ooltewah, Tenn.
`[73] Assignee: Harris Tube Pulling and
`Manufacturing Company, Ooltewah,
`Tenn.
`[21] Appl. No.: 543,792
`[22] Filed:
`Oct. 21, 1983
`
`Related U.S. Application Data
`[63] Continuation of Ser. No. 212,160, Dec. 2, 1980, aban(cid:173)
`doned.
`Int. Cl,4 .............................................. B23P 19/04
`[51]
`[52] U.S. Cl •..................................... 29/727; 29/426.4;
`226/187; 254/29 R
`[58] Field of Search ...................... 29/726, 727, 426.5,
`29/252, 426.4; 254/29 R, 93 R; 226/186-188;
`271/273-274; 72/246
`References Cited
`U.S. PATENT DOCUMENTS
`1,591,322 7/1926 Karmazin .............................. 29/727
`1,950,623 3/1934 Owston ................................. 29/727
`3,339,393 9/1967 Rice ...................................... 72/246
`3,785,026 1/1974 Ohmstede .......................... 29/157.4
`3,924,316 12/1975 Matlock et al ........................ 29/726
`
`[56]
`
`4,033,496 7/1977 Rolfe ................................... 226/187
`4,044,444 8/1977 Harris .................................... 29/727
`4,125,928 11/1978 Cawley et al ......................... 29/282
`4,132,099 1/1979 Elsener .................................. 72/175
`4,150,477 4/1979 Orr ........................................ 29/252
`FOREIGN PATENT DOCUMENTS
`1315664 5/1973 United Kingdom .
`Primary Examiner-Daniel C. Crane
`Attorney, Agent, or Firm-Vincent L. Barker, Jr.
`[57]
`ABSTRACT
`An extractor for pulling individual tubes from a tube
`sheet in a heat exchanger. The extractor includes a pair
`of serrated, drive wheels or drivers mounted in a hous(cid:173)
`ing on parallel rotating shafts. The tube drivers have
`inclined teeth which project into opposite sides of a
`passageway along which a tube is drawn. The spacing
`between the drivers is adjustable to accommodate dif(cid:173)
`ferent sized tubes, and the drivers are spring biased
`towards each other, to provide a constant gripping
`force on a tube within the passageway. The drivers are
`respectively rotated by two hydraulic motors, with the
`hydraulic power supply connected in series, thereby
`providing substantially synchronous rotation of the
`drivers.
`
`6 Claims, 2 Drawing Sheets
`
` Ex.1014 p.1
`
`

`
`U.S. Patent Mar. 28, 1989
`
`Sheet 1of2
`
`4,815,201
`
`FIG.
`
`10
`
` Ex.1014 p.2
`
`

`
`U.S. Patent Mar. 28, 1989
`
`Sheet 2of2
`
`4,815,201
`
`62
`
`FIG. 2
`
` Ex.1014 p.3
`
`

`
`1
`
`TUBE TRAVELER DEVICE
`
`4,815,201
`
`2
`Moreover, the use of spur gears to assure synchro(cid:173)
`nous rotation of the drivers, as disclosed by Harris and
`Curfman et al., requires that the shafts mounting the
`gears and drivers be at a fixed distance to each other, to
`S assure proper intermeshing of the gears. This require(cid:173)
`ment renders it difficult to adapt the extractor to accom(cid:173)
`modate tubes of different diameters.
`As disclosed by Harris and Ohmstede, it has been
`found advantageous to grip tubes between drivers with
`a force sufficient to deform the tubes as they are drawn
`out of the tube sheet. However, scale accumulations
`within a tube may be sufficient to form a plug that inter(cid:173)
`feres with the deformation of the tube by the drivers.
`Such a plug will jam an extractor having drivers
`mounted on fixed shafts, thus slowing the renewal pro(cid:173)
`cess and sometimes injuring the extractor itself.
`Accordingly, it is an object of this invention to pro(cid:173)
`vide a high speed tube remover capable of use within
`various sized tubes, which is jam-free, and which over(cid:173)
`comes other deficiencies of the prior art.
`SUMMARY OF THE INVENTION
`The invention provides a tube extractor comprising
`two rotary drivers respectively mounted in two hous(cid:173)
`ings for rotation about spaced apart parallel axes. The
`facing or adjacent surfaces of the drivers and housings
`define between them a passageway for axial movement
`of a tube. The housings are slidably mounted on rods
`interconnecting the housing, whereby the distance be(cid:173)
`tween them and thus the spacing of the driver axes may
`be adjusted to accommodate tubes of different diame(cid:173)
`ters. The drivers are spring biased toward each other
`with a spring force sufficient to deformably grip a tube.
`When a plug within a tube is encountered as the tube
`travels between the drivers, the spring bias will be over(cid:173)
`come, permitting the housings and drivers to shift apart
`slightly as the obstruction passes.
`The drivers are respectively driven by two positive
`displacement hydraulic motors. The two hydraulic mo(cid:173)
`tors are series-connected, that is, the power fluid ex(cid:173)
`haust of one supplies the power fluid input for the other.
`As the hydraulic fluid is incompressible, there is no
`slippage between the two motors, thereby assuring
`synchronous co-rotation of the two drivers.
`Accordingly, it is an object of the present invention
`to provide a tube traveler with relatively lightweight
`means for assuring positive co-rotation on the drivers.
`It is another object of the invention to provide such a
`tube traveler in which the distance between the shafts
`mounting the drivers is relatively easily adjustable, to
`accommodate tubes having diameters of different sizes.
`It is a further object of the invention to provide a tube
`traveler in which the driver shafts are moveable relative
`to each other during operation, to compensate for vary(cid:173)
`ing the degree of tube deformation, while still maintain(cid:173)
`ing synchronous co-rotation of the drivers.
`Other objects and advantages will be apparent to
`those skilled in the art from the following detailed de(cid:173)
`scription of a preferred embodiment.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a perspective view showing a tube traveler
`in accordance with the present invention, pulling a tube
`from a tube sheet in a heat exchanger.
`FIG. 2 is a vertical cross-sectional view of a tube
`traveler taken along line 2-2 of FIG. 1.
`
`30
`
`20
`
`This application is a continuation of Ser. No. 212, 160,
`filed Dec. 2, 1980, now abandoned.
`BACKGROUND OF THE INVENTION
`Many heat exchangers are of an indirect type which
`employs tubes for carrying a heat transfer fluid. A large
`number of tubes are mounted to extend in a parallel IO
`array between two supporting tube sheets in the heat
`exchanger. The tubes are pressed fit into or expanded
`into engagement with openings through the tube sheets,
`thus forming a fluid tight seal. A heat transfer fluid,
`such as water, is circulated through the parallel tubes IS
`between the tube sheets while a higher temperature
`fluid, such as combustion gases or heated water, is cir(cid:173)
`culated past the exterior of the tubes between the two
`tube sheets for achieving an indirect heat transfer be-
`tween the two fluids.
`It is sometimes necessary to remove tubes from the
`tube sheet in which they are mounted. Removal may be
`necessary for many reasons, such as leaks in the tube or
`excessive scale accumulations within the tubes. The
`removal and replacement of tubes may be done on a 2s
`regular preventative maintenance schedule. In any case,
`the replacement operation entails costly downtime for
`the heat exchanger. This is particularly true in the case
`of large electric power generating equipment where a
`given installation may have thousands of tubes and
`downtime is costly to the owner and can be inconve(cid:173)
`nient to the power customer.
`To remove tubes from such a heat exchanger, the
`interference fit between the tube end and the tube sheet 3s
`is first relieved, then the tube is axially moved several
`centimeters to present an end projecting beyond the
`tube sheet which may be gripped by a tube extractor.
`Typical of tube pulling devices is that shown in com(cid:173)
`monly-owned U.S. Pat. No. 3,835,520 or in U.S. Pat. 40
`No. 3,628,246.
`Once the tube has been broken loose and axially
`moved to expose an end beyond the face of the tube
`sheet, it is gripped by another device of the type shown
`herein which rapidly moves it out of the tube sheets. 4S
`Inasmuch as some tubes in such large power installa(cid:173)
`tions may be 10-20 meters long, the rapid removal by an
`extractor device is necessary to effect good economics
`during serving. Prior art devices for removing long
`tubes from tube sheets axially at high rates of speed are so
`disclosed in U.S. Pat. Nos. 3,149,021 (Curfman)
`3,785,026 (Ohmstede), and 4,044,444 (Harris) the latter
`being commonly owned by applicant. These devices
`generally comprise at least a pair of rotating rollers or
`drivers mounted on parallel axes and adapted for engag- ss
`ing in the nip a tube extending between the drivers. The
`drivers are rotated in opposite direction to impart an
`axial motion to the tube.
`To provide the most efficient gripping forces be(cid:173)
`tween the drivers and the tubes, it is preferable that the 60
`drivers rotate synchronously, without the possibility of
`relative slippage between them. The apparatuses dis(cid:173)
`closed by Harris and Curfman et al. assure this desired
`synchronization by gearing the drivers together for
`operation by a single motor. However, the necessary 6S
`spur gears and means for mounting them add consider(cid:173)
`able weight and expense to the extractor, increasing the
`difficulty of the extraction process.
`
` Ex.1014 p.4
`
`

`
`4,815,201
`
`3
`DESCRIPTION OF A PREFERRED
`EMBODIMENT
`FIG. 1 illustrates a tube extractor 10 in accordance
`with the present invention in the process of extracting a 5
`tube 12 from a tube sheet 14 of a heat exchanger. The
`tube 12 has already been partially extracted, by any
`known means, such as the tool disclosed in U.S. Pat.
`No. 3,835,520, to present an exposed end of the tube 12
`for gripping by the tube extractor 10.
`The extractor 10 includes two opposed rotatable
`drivers 16, 18 adapted for engaging between them the
`tube 12 and pulling it from the tube sheet 14. The driv(cid:173)
`ers 16, 18 are respectively mounted on parallel shafts 20.
`Each shaft 20 is mounted on two sets of bearings 23 15
`press fit into the housings 24 and 26. As illustrated, in
`operation, the housing 24 and 26 abut the tube sheet 14
`and define between their facing surfaces 25 and 27 a
`passageway for. axial movement of a tube 12.
`To assure appropriate spacing between the drivers 16 20
`and 18 for proper gripping of the tubes 12, means are
`provided for adjusting the distance between housings 24
`and 26. Housings 24 and 26 are positioned relative to
`each other by a plurality of parallel rods 28. The rods 28
`are perpendicular to the axis of the passageway defined 25
`between the housings 24 and 26. Each rod 28 extends
`from the outside of housing 24, through a countersunk
`bore 30 in housing 24, across the passageway between
`the housings, and through a coaxial countersunk bore
`formed through housing 26. The ends of rods 28 are 30
`threaded for stop nuts 34 which limit the separation
`between the housing 24 and 26, and thus the width of
`the passageway between them and the size of the nip
`between the drivers 16 and 18.
`Helical springs 36 respectively surround each rod 28. 35
`The springs 36 associated with housing 24 extend into
`the countersunk bores 30 and are retained between stop
`nuts 34 and the end face of the countersunk bore which
`defines a reduced diameter bore section adjacent the
`inside surface 25 of the housing 24. Similarly springs 36 40
`associated with housing 26 extend into countersunk
`bores formed in housing 26, and are retained between
`stop nuts 34 and the end face defining a reduced diame(cid:173)
`ter bore.
`Springs 36 will resist separation of the drivers 36 and 45
`18 beyond a preselected distance. This distance and
`more importantly the compressive force on a tube 12
`between the drivers 16, 18 may be adjsted by means of
`stop nuts 34 which adjust the effective length of the
`rods 28. Preferably, the compressive force is sufficient 50
`to deform a tube 12 in the nip between the drivers 16
`and 18, as illustrated in FIG. 1, to assure good engage(cid:173)
`ment and traction by the teeth on the drivers 16 and 18.
`Tubes may sometimes be encountered which have
`excessive internal scale deposits forming a plug within 55
`the tube 12 that resists crushing. In such a situation, the
`spring bias mounting of the drivers 16 and 18 prevents
`a tube 12 jamming between them. Instead, the drivers 16
`and 18 merely follow the outer contour of the tube 12,
`shifting the housings 24 and 26 apart and compressing 60
`the springs 36. As the obstruction passes, the springs 36
`return the housings 24 and 26 and the drivers 16 and 18
`to their original position, thus providing a continuous
`gripping force on the tube 12.
`It has been found advantageous to rotate all drivers 65
`synchronously to achieve the most reliable gripping
`force against a tube. In prior art devices, a drive chain
`including spur gears between driver shafts has been
`
`4
`employed to achieve this necessary positive co-rotation.
`Such gear structure, however, results in a h~avy struc(cid:173)
`ture subject to wear and friction. More importantly, an
`extractor with geared together shafts has limited shock
`absorption capacity, if the shafts are fixed relative to
`each other.
`To achieve these problems of known tube pullers, the
`two drivers 16 and 18 of the tube extractor 10 are ro(cid:173)
`tated respectively by two series-connected, positive
`10 displacement hydraulic motors 44 and 46. The motor 44
`is bolted to the housing 24 and its shaft is connected to
`the shaft 20 of the driver 16. Similarly, the second hy(cid:173)
`draulic motor 46 is bolted to the housing 26 and drives
`the shaft 22 of the second driver 18. The motor 46 re(cid:173)
`ceives the hydraulic power fluid under pressure
`through a line 50. Exhaust hydraulic fluid is carried by
`a line 52 from the outlet of the first motor 46 to the inlet
`of the second hydraulic motor 44. Exhaust hydraulic
`fluid from the motor 44 is recirculated through a line 54
`to the source of the pressurized hydraulic fluid. Thus
`there exists the same flow rate through each motor 44
`and 46 and the same pressure drop across each motor 44
`and 46. As the hydraulic fluid is incompressible, the
`hydraulic motors 44 and 46 are continuously driven at
`the same speed and power.
`The hydraulic motors 44 and 46 are actuated by a
`solenoid controlled valve. The valve (not illustrated) is
`within the sealed housing of the motor 44, and is respon(cid:173)
`sive to a magnetic field. A handle 60 rigidly secured to
`the housing of the motor 44 contains a solenoid coil (not
`illustrated) and a control switch 62 therefor. The handle
`60 is preferably slanted away from the axis of the tube
`12, so that the tube extractor can more easily be oper-
`ated from a safe position to the side of the tube 12.
`The above described embodiment provides a tube
`traveler which is efficient in operation and mechani(cid:173)
`cally simple. Seriers-connected positive displacement
`motors replace less reliable spur gears as a means to
`provide synchronous co-rotation of the drivers. This
`drive system permits an arrangement in which the
`motor and drivers are shiftably mounted relative to
`each other, thus eliminating the possibility of the tube
`jamming. Adjustable spring biased mounting of the
`drivers permits selecting of a gripping force sufficient to
`deformably grip tubes of different diameters.
`Although a preferred embodiment of the invention
`has been described in detail, various modifications and
`changes may be made without departing from the spirit
`and scope of the invention as defined in the appended
`claims.
`I claim:
`1. A tube traveler for axially removing a metal tube
`mounted in an opening formed through a tube sheet, the
`tube being sized to fit in interfering relationship with the
`opening and exerting a relatively large amount of resis(cid:173)
`tance to such axial removal, said tube traveler compris(cid:173)
`ing in combination:
`a pair of adjacent housings, each of said housings
`having a rear face adapted for abutment against
`such tube sheet and a facing surface, each of said
`housings containing a rotary driver journalled for
`rotation within said housing and positioned such
`that the periphery of each driver extends beyond
`said facing surface;
`motor means connected to each of said rotary drivers
`and effective to synchronously drive the same in
`opposite directions;
`
`Ex.1014 p.5
`
`

`
`4,815,201
`
`5
`means for positioning said housings such that said
`facing surfaces face each other while permitting
`relative movement of said housings; and means for
`biasing said housings toward each other such that
`said peripheries of said rotary drivers normally 5
`engage and substantially deform a tube therebe(cid:173)
`tween to translate such tube along its axis, said
`biasing means allowing said housings to separate
`beyond said normal position such that said rotary
`drivers may pass over a portion of such tube there- 10
`between which cannot be substantially deformed.
`2. The tube traveler of claim 1 wherein said position(cid:173)
`ing means includes a plurality of rods extending
`through said housings transversely across said tube path
`and said biasing means positions said housings to pro- 15
`vide a normal extension of said drivers into said tube
`path, said bias means exerting sufficient lateral force
`upon said tubes to substantially deform the same when
`
`6
`passing along said tube path between said rotary driv(cid:173)
`ers.
`3. The tube traveler of claim 2 wherein said bias
`means comprise annular compression springs circumja(cid:173)
`cent said rods and adapted to urge said housings toward
`said normal position.
`4. The tube traveler of claim 3 which further includes
`means for adjusting the amount of compression on such
`compression springs when in said normal position.
`5. The tube traveler of claim 1 wherein said motor
`means includes a positive displacement hydraulic motor
`connected to each of said rotary drivers.
`6. The tube traveler of claim 5 wherein each of said
`rotary drivers is directly secured to the output shaft of
`said hydraulic motor such that the rotary speed of said
`driver and motor are equal.
`* * * * *
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
` Ex.1014 p.6