US3293963A - Pile cutter - Google Patents

Description

Dec. 27, 196% J. J. CARROLL ETAL 5 Sheets-Sheet 1 JOSEPH J. CARROLL .JOHN B. GALLETTI, JR JOSEPH F. O'KELLY, JR

FILE CUTTER Filed March 10, 1965 6O 6 fie a o 40 o 58 33 36 Ill 34 H u! i i" 3V 13 13 16 II I 1 33 o 33 G) 4 V HGURE 1 INVENTORS TTORNEY Dec. 27, 1966 J. J. CARROLL ETAL FILE CUTTER 5 Sheets-Sheet 2 Filed March 10, 1965 FiGURE 2 PILE JOSEPH J. CARROLL JOHN B. GALLETTI, JR. JOSEPH F. O'KELLY, JR.

INVENTORS ATTORNEY .11. J. CARROLL ET AL 3,293,963

PILE CUTTER Dec. 27, 1966 5 Sheets-Sheet 5 Filed March 10, 1965 I W 'APILE FIGURE 3 JOSEPH J. CARROLL JOHN B. GALLETTI, JR- .JOSEPH F. O'KELLY, JR.

INVENTORS BY @pfMg ATTORNEY Dec. 27, 1966 J. J. CARROLL ETAL 39 3 FILE CUTTER Filed March 10, 1965 5 Sheets-Sheet 4 JOSEPH J. CARROLL JOHN B. GALLETT'I, JR. JOSEPH F. O'KELLY, JR.

INVENTORS ATTORNEY ec. 7 1R6 J, J, CARRQLL E 3,293,963

FILE CUTTER 5 Sheets-Sheet 5 Filed March 10, 1965 FIGURE 4 c FIGURE 5 a JOSEPH J. CARROLL JOHN B. GALLETTI JOSEPH F. O'KELLY,JR.

I NVENTORS ATTORNEY FIGURE 5 United States Patent 3,293,963 FILE CUTTER Joseph I. (Carroll and John B. Galletti, In, Pasadena,

and Joseph F. OKelly, Jr., La Porte, Tex., assignors to J and .I Marine Diving Company, Pasadena, Tex., a

corporation of Texas Filed Mar. 10, 1965, Ser. No. 438,686 14- Claims. (CI. 83-54) The present invention is a novel type pipe cutter, one which may be lowered into an upstanding pipe and sever it into two parts by cutting the wall from the inside. Briefly stated, it consists of an assembly of elements which support one or more rotary cutters at a predetermined position along the length of the pile, cause such cutters to rotate about their own axes, move the cutters radially with respect to the axis of the pile to cut through the wall of the pile and then cause the cutters (still rotating) to rotate satellite fashion about the pile axis to complete the cut.

The invention herein disclosed was conceived and developed to supply the need for a tool to out large piles which are driven into underwater beds and extend upwardly through the overlying water to support a steel framework which supports an offshore drilling platform, the framework including jacket tubes which slip down over the piles and braces running between the jacket members. Such a pile or pipe is from two to four feet in diameter, and its wall thickness is from to 2 inches. If the drilling platform and its supporting framework are moved, it is desirable to salvage as much of the pile as possible by cutting it and leaving the stub in the ocean floor, preferably cutting from the inside because the level of solids inside the pipe has been reduced by pumping to a point several feet below the mud, sand and shell surrounding the pile, Since the pile may cost as much as $100 a running foot, it is worthwhile to salvage as much of it as possible.

Heretofore the common method of cutting such piles has been by lowering a man into the pipe to perform the operation manually with a cutting torcha slow, expensive and hazardous technique. Since the pile is usually filled with water, the man who does the work must necessarily wear diving equipment and be supplied with oxygen as well as welding gases through tubes running down through the pile from surface equipment, thus adding further to the cost, and to the danger to the diver.

In approaching the present invention, the undersigned first considered the well known pipe cutters used in cutting small diameter surface pipes from the outside surface inwardly, and easing cutters in cutting oilwell casing outwardly from the inside surface. Both such cutters use small wheels or disc each having it circumferential periphery tapered and sharpened to a cutting edge. The wheels are rolled on the surface of the pipe or casing with thrust applied radially through the cutting edge to the surface of the pipe wall. While efiicient enough for thin-walled pipes, devices using such cutting discs become increasingly inefiicient as the thickness of the pipe increases, and fail completely for pipes having a wall thickness in excess of about /2 inch. This limitation is apparently a result of the fact that such rolling wheels do not actually remove material by chipping, abrading, or the like, but on the other hand penetrate the material of the pipe wall and roll it aside in the manner of a plow.

To better enable those skilled in the art to understand the pile cutter herein divulged, a drawing is attached as a part of the application. In this drawing:

FIGURE 1 is a perspective view of one preferred embodiment of the invention,

FIGURE 2 is a longitudinal section of the same embodiment as it appears inside a pile prior to any movement of the cutters and prior to actuation of the means used to secure the device to the inside surface of the pipe wall, only the upper half being shown because the lower half is identical with the upper except for the omission of certain parts from the lower half,

FIGURE 3 is also a longitudinal section of the upper half of the same embodiment, this view being drawn after actuation of the securing means and after the cutters have been moved radially and have cut through the pile,

FIGURE 4 is a cross section as indicated by the arrows 4-4 of FIGURE 2, this figure illustrating the rotary cutters in the retracted position they occupy when the device is being lowered into position or hoisted back to the surface,

FIGURE 4a is the same as FIGURE 4 except that the cutters, While rotating about their own axes, have made their initial cuts through the pile wall under radial thrust applied by the illustrated hydraulic means,

FIGURE 4b is also the same as FIGURE 4 but shows another step in the sequence of operations, the cutters having been orbited to out part of the pile wall and the wedge cylinders having been actuated and being near the end of their outward radial strokes,

FIGURE 40 is also the same as FIGURE 4 buts shows the wedge cylinders retracted to their starting positions leaving the wedges forced into the cuts to prevent the cutters from being pinched by the weight of the upper part of the pile,

FIGURE 5 is a cross-section as indicated by the arrows 5-5 of FIGURE 3, this view showing the set of rollers used in lowering and raising the device to prevent damage to the other parts,

FIGURE 5a is a detail of a section taken in the same plane as was FIGURE 5, showing one of the same set of rollers relocated for use of the device in cutting a smaller pile, and

FIGURE 6 is a top view of the rotary actuator at the top of the device, as indicated by arrows 66 of FIG- URE 3.

Referring to the drawing for a more detailed description of the invention, the preferred embodiment illustrated comprises the major units or sub-assemblies (shown by arrows) of a cutter wheel assembly 1 secured by key '3 to a central shaft 25 at about the longitudinal midpoint of the device, a pair of radially extendible gripper assemblies 30, one above and the other .below the cutter wheel assembly and each pivotally secured at its end adjacent the cutter wheel assembly to a collar 31 secured to shaft 25 so that it can not slide therealong but permitting the shaft to rotate within the collar, and at their distal ends to a similar collar 32 which is both rotatably and slidably secured to shaft 25 and is also secured to one of a pair of roller assembly 40 for longitudinal movement therewith, and the rotary actuator assembly 60' mounted at the top of the device.

In the description above and following, and in the appended claims, the pile cutter is described according to the vertical orientation illustrated in the drawing. It is to be understood, however, that this is done only to provide a frame or reference, and that the device is capable of severing pipe no matter how severely it is inclined from the vertical.

The cutter wheel assembly 1 includes a horizontal plate 2 having a hub 4 secured to vertical shaft 25 by one or more keys 3 and having therein one set of recesses 6 to accommodate circular cutting blades 5 throughout its range of radial positions and a second set of recesses or slots 8 to accommodate wedge cylinders 9 and wedges 10. Each cutting blade 5 is keyed to an individual shaft I11 driven by a motor 12 mounted on a pivot arm 14 which is pivotally secured to plate 2 by vertical pins 13,

and is thus able to move in a horizontal plane, normal to the central shaft 20, while being rotated about its own axis by motor 12 and shaft 11. Such horizontal motion is supplied by horizontal hydraulic cylinders 16, each pinned to a pivot arm 14 by a vertical .pin 17 and having its extensible piston 18 secured to a lug 15 projecting outwardly from hub 4 by the :pin and clevis unit 19.

The hydraulic wedge cylinders 9 are preferably secured to plate 2 with a radial orientation, as space allows, or nearly radially, as illustrated, by vertical mounting pins A piston 23 extending from the outer end of each cylinder terminates in an open-ended sleeve 22 which serves to accommodate a wedge 10 held firmly in the sleeve but axially slidable therefrom when gripped under modest pressure. While the cylinders 9 may be actuated at various times, the preferred time is shortly after the blades have made their initial (radial) cuts and a short part of their circumferential cuts, as shown in the sequence of FIGURES 4a, 4b and 40. This insures against pinching of the blades as the upper part of pile stretches under its own weight (being held only at its upper end), as it is likely to do if the wedges are not inserted until or shortly before the circumferential cuts are completed to finish severing the pile.

Each gripper assembly 30, see FIGURES 2 and 3, includes a multiplicity of gripper blocks 33, preferably three or more equally spaced cireumferentially about central shaft 25. Each block 33 is knurled or otherwise roughened on its outer surface 34 for frictional engagement with the surface of the pile to prevent any axial movement of the cutter assembly 1 while cutting wheels 5 are turning, and also to transmit countertorque to the pile during orbital movement of cutting blades as more fully described below. Each block is pinned by horizontal pivot pins 36 at the midpoint or knee of a linkage consisting of upper arms 37 pivotally secured at their upper ends to distal collar 32 by horizontal pins 35 and lower arms 38 pivotally secured at their lower ends to proximal collar 31 by horizontal pins 39, the other end of each of arms 37 and 38 being pinned to block 33 by the common horizontal pin 36.

Each roller assembly 40, see FIGURE 5, consists of a horizontal plate 41 having a series of small vertical plates 42 secured to its circumferential perimeter at equally spaced intervals, and a like number of roller assemblies 43 secured to the small plates. Each roller assembly 43 consists of a yoke having a plate 44 demountably secured to plate 42, a pair of spaced arms 45 extending radially outwardly therefrom, a horizontal shaft 46 extending through holes in arms 45, and an idler wheel or roller 47 mounted on the shaft. To make the assembly 40 adaptable for use in cutting a smaller diameter pile, plate 41 is notched to form alternating extensions 48 and notches 49. A second set of small plates 51 are secured to the plate 44 at the inner ends of the notches, and the roller assemblies 43 may be moved to such locations, as illustrated in FIGURE 5a.

Secured to the inner surface 52 of plate 41 of each roller assembly (see FIGS. 2 and 3) are a pair of vertical hydraulic cylinders 53, and pistons 54 of which extend through plate 41 and have their outer ends 59 secured to a smaller and horizontal thrust plate 58 mounted on central shaft 25, the arrangement being such that neither of plates 41 and 58 rotates with the shaft and plate 41 is also axially slidable on the shaft. When cylinders 53 are actuated to extend their pistons 54, thrust plate 58 remains fixed, as does piston 54, but cylinder 53 moves axially towards cutter assembly 1, carrying roller assem bly 40 and collar 32 with it. Lower arm 38 of the gripper assembly swings about its fixed pivot 39 while upper arm 37 swings about its descending upper pivot 35 to force their floating common pivot 36 outwardly (and downwardly) to bring gripper blocks 33 into forceful contact with the pile, as shown in FIGURE 3.

A pair of slotted vertical bars 55 extend upwardly and have their lower ends secured to plate 41 of the upper roller assembly 40. As shown in FIGURE 6, each bar 55 is disposed to slidably contact one side 57 of the polygon-shaped periphery of thrust plate 58, this arrangement permitting relative axial movement between plates 41 and 58 but preventing relative rotation therebetween. Many other such common-rotation-and-axial-slidability connections may also be used, e.g., splining to a common sleeve, the arrangement shown being one of the simplest and being aided by the engagement of lugs 61 protruding from edge 57 of the thrust plate to engage vertical slots 56 in the vertical torque bars 55.

A pair of eye bolts 62 mounted on upper thrust plate 58 permit the attachment of cables (not shown) for raising and lowering the entire pile cutter assembly. Also mounted on upper thrust plate 58 is the rotary actuator 60, the rotor of which is keyed to the upper end of central shaft 25 for the application of torque thereto to turn the cutter wheel assembly 1 during the orbital cutting strokes of blades 5. Such rotary actuator is a slow acting device set for the limited portion of a single revolution, e.g., something less than degrees for the 4-blade pile cutter illustrated, a limitation necessary to prevent the cutting of wedges 10 (if the orbital stroke continued further than necessary).

The pile cutter thus described has all of its major subassemblies mounted on a central shaft 25 with various arrangements respecting movements relative to movements of the shaft. Thus the only sub-assemblies which both rotate with the shaft and are not slidable thereon, for which the expression keyed is employed, are cutter wheel assembly 1 and rotary actuator 60 (or, more exactly, the rotor thereof, as the housing of the rotary actuator is secured to thrust plate 58). No other subassemblies or parts thereof rotate with shaft 25, and in addition roller assemblies 40 and the distal ends of gripper assemblies 30 are slidable on the shaft. Since the rotor of rotary actuator 60 cannot be pulled out of its housing and such housing is anchored to thrust plate 58, the thrust plate 58 cannot slide on the shaft, but the shaft extends through this plate with a clearance to prevent their common rotation.

In operation, the pile cutter is lowered into the pile by the cables attached to eye bolts 62 with all elements retracted, in the positions shown in FIGURES l, 2 and 4. During the lowering movement, the rollers 43 of the roller assemblies 40 roll on the inner surface of the pile as necessary to prevent contact of any other part of the device with the pile, as the roller assemblies have a larger diameter than either the retracted cutter assembly or the retracted gripper assemblies. When the cutting position has been reached, surface control equipment is operated to supply a flow of hydraulic fluid through lines not shown through the vertical hydraulic cylinders 53, cansing a vertical movement of cylinders 53, roller assemblies 30 and collars 32 toward cutter wheel assembly 1, such movement continuing until gripper blocks 33 are firmly engaged with the inner surface of the pile wall, thus fixing and centering cutter wheel assembly 1 in position. The next step is to actuate motors 12 and hydraulic cylinders 16 to cause cutters 5 to rotate on their own axes and move radially outwardly (actually only approximately radially) to make their first cuts through the pile wall, ending as indicated in FIGURES 3 and 4a.

Thereafter rotary actuator 60 is actuated, again by surface control equipment supplying a flow of hydraulic fluid through lines not shown to turn shaft 25 and cutter assembly 1 sufficiently far to allow the insertion of wedges 10, as shown in FIGURES 4b and 4c, after which orbital cutting is resumed and continued until severance is completed. The cutter wheels are then retracted, gripper assemblies 30 are moved from the FIGURE 3 position to the FIGURE 2 position, and the entire device is hoisted from the severed upper piece of the pile. Wedges 10 are regarded as expendable, and are not recovered.

During the rotation of shaft 25 by rotary actuator 60, counter-rotation of the actuator housing and its support is prevented by a counter-torque supplied by the pile itself. The counter-torque is from the pile to gripper blocks 33, through distal arms 37, collars 32, plate 41, torque bars 55, plate 58 to the housing of rotary actuator 60.

Having described the preferred embodiment, applicants believe it to be apparent that they have disclosed a relatively simple device which can be lowered into a pile and sever it close to its lower end without the need for a diver. Their pile cutter is'completely surface controlled, and will cut piles of all diameters and wall thicknesses in a minimum of time. Various power means other than the hydraulic motors shown may be used to rotate the cutting blades and the shaft, e.g., air motors or electrical motors, and similarly other power means than the hydraulic means shown may be used to operate the gripper assemblies and cutter wheels. The hydraulic power circuits have not been described in detail because they are believed to follow conventional practice.

The essence of the invention is a cutting wheel assembly in which at least one independently powered cutting wheel is mounted so that it can be moved radially from a retracted or rest position spaced from the inner surface of the pile to a cutting position wherein it contacts such surface while rotating, can then make an initial cut through the wall under the influence of a radially applied force, and thereafter can be orbited about the axis of the pile to make a girth or circumferential cut which severs the pile into two parts. The cutter wheel may be any of several conventional types, e.g., milling cutters of the type used in machining a steel workpiece of large mass. It is preferred to use a multiplicity of such cutters operating simultaneously, the better to cut the pile in a minimum of time. It is not essential that the cutters be disposed and operate in a plane orthogonal to the pile axis, as they could operate in a plane slanted with respect to the pile, but the orthogonal disposition and operation is preferred for basic reasons-to minimize the length of cut necessary and to simplify the components of the structure.

It is necessary, of course, to provide a means such as the pivot arms and hydraulic cylinders shown in order to move the cutter wheels from their rest positions-to their extended radial positions. It is recognized that this could be accomplished by mounting each cutter and its associated shaft and motor at the outer end of a radially disposed hydraulic piston operating in a cylinder which is fixed with respect to a central shaft. It is also possible to modify the preferred arrangement shown so that the cutting wheel leads the pivot point of its pivot arm during rotation, but this disposition (or mode of operation, as the same result, see FIGURE 4, can be obtained by rotating cutter wheel assembly 1 counter-clockwise rather than in the preferred clockwise direction) is believed to cause more wasteful vibration than the one described.

To permit the cutters thus to operate, it is of course necessary to secure them against movements up and down within the pile, i.e., movements in any directions other than in the cutting plane in which they are to operate. While applicants prefer the knee-action type gripper assembly shown, they recognize that other means are also feasible, e.g., a multiplicity of gripper block assemblies extended by radially moving hydraulic pistons, as shown in the prior art.

What is claimed is:

1. A cutter assembly for a pile cutter comprising a support plate adapted to be keyed to the central shaft of the pile cutter, a multiplicity of rotary cutting blades disposed between the central shaft and the pile wall in a cutting plane transverse said wall, each blade being supported from said support plate for radial movement in said plane, first power means for rotating said blade during such radial movement and thereafter, and second power means for moving such blade and holding it in a predetermined position as said assembly is rotated by said shaft.

2. A cutter wheel assembly for an internal pile cutter which includes a central shaft and a gripper assembly means mounted on the shaft to prevent axial movements of the cutter wheel assembly, said cutter wheel assembly comprising at least one rotary cutting wheel disposed between said shaft and the inner wall of a pile and supported by said shaft so that it is movable in a plane transverse thereto, independent power means for rotating said cutter wheel, and second power means supported from said shaft for moving said cutting wheel into contact with said pile wall, for forcing the cutter through the wall while rotating and in cutting contact therewith, for holding said cutting wheel in cutting contact with the wall after it has completed an initial radial cut and the shaft, cutter wheel, independent power means and second power means are altogether rotated about the axis of said shaft, and for retracting said cutter wheel and its independent power means to their original position after cutting the pile.

3. An internal pile cutter which includes at least one rotary cutter having a blade adapted to be disposed in a cutting plane transverse the axis of the pile, said blade being of smaller diameter than the inside diameter of the pile, power means for moving said blade radially in said cutting plane from a retracted position inside and spaced from the inside surface of the pile to an extended position in which part of the blade extends through the outer surface of the pile, rotating means for rotating said blade while it is in cutting contact with said pile, and means for orbiting said cutter about the axis of the pile While it is in said extended position and is rotating about its own axis.

4. A cutter assembly adapted to be secured for common axial and rotary movement to the elongated shaft of a pile cutter which is lowered into such pile with the shaft coaxial with the pile, said cutter assembly comprising a support plate secured to the shaft, a number of rotary cutting wheel blades secured to said plate for radial movement in a cutting plane transverse of said shaft from a retracted position inside the pile to an extended position in which it has cut through the pile, a first power means for rotating each of said blades as it moves through said positions and continuing to rotate them while in extended position, and a second power means for moving each of said blades through said positions, holding them in extended position While said assembly is rotated with the shaft to orbit the rotating blades about the pile axis to completely sever the pile and, moving them back to their retracted position.

5. A pile cutter adapted to be lowered into a typically vertical pile and sever the same by cutting it outwardly from its inside surface, said pile cutter comprising:

(A) a central support shaft adapted to be coaxially disposed within said pile,

(B) a cutter wheel assembly comprising a horizontal plate keyed to said shaft, a number of pivot arms each pivoted at one end to said plate by a vertical pin through the plate spaced from said shaft, an independently powered cutting wheel mounted on the other end of the pivot arm, power means for pivoting said arms and the respective cutting wheel, While rotating, to move each said wheel into cutting engagement with the pile wall to make radial cuts therethrough, and second power means to rotate said shaft and cutter assembly to sever said pile.

6. A pile cutter adapted to be lowered inside an upstanding pile and sever it into two parts by a girth cut, comprising a central shaft adapted for coaxial disposition within the pile, a cutter wheel assembly including a plate keyed to and extending transversely from said shaft, a number of rotary cutting wheels mounted'on pivot arms secured to said plate for moving said wheels radially between said shaft and said pile, each of said cutting wheels being disposed to rotate about an axis parallel to the pile wall and being provided with independent rotary, power means, power means acting on each of said pivot arms to move said cutting wheels radially and hold them in cutting contact with said pipe wall and to hold them in a predetermined position thereafter, and means for rotating such central shaft to move said cutting wheels, while rotating about their own axes, circumferentially to complete the severance of said pile.

7. A pile cutter for cutting a pile from the inside comprising an elongated central shaft adapted to be disposed coaxially within a pile, at least one rotary cutting wheel disposed on a shaft parallel to and offset from said central shaft, said rotary cutter being mounted on means secured to said central shaft whereby the cutter and its shaft are movable radially to bring the cutting edge of the cutter into forceful cutting contact with the inner surface of the pile wall while said cutter is revolving about its own axis and hold said cutter in extended position after it has completed a radial cut through said pile wall, and power means for rotating said shaft and at least one cutting wheel, still revolving on its axis, about the axis of the pile to sever said pile completely.

8. A pile cutter comprising a number of rotary cutting blades disposed to rotate in a cutting plane transverse the axis of the pile, each blade being mounted for radial movement in said cutting plane from a recessed position inside and spaced from the pile wall to a range of cutting positions in which it cuts through the pile wall while rotating about its own axis, a first power means for rotating each said blade, a second power means for moving each said blade through said range of positions, said second power means being controllable to hold the blade in extended position after it has cut through the pile wall, an elongated shaft disposed generally coaxially with said pile, said number of cutting blades and first and second power means being rotatably mounted on said shaft, and a third power means to rotate said shaft to orbit said number of cutting blades around said pile while each is rotating about its axis in cutting engagement with the pile wall.

9. An internal pile cutter comprising an elongated shaft adapted to be disposed coaxially with the pile, means non-rotatably mounted on said shaft for securing it to the shaft against relative axial movement, a cutter wheel assembly secured to said shaft for common rotation therewith, and a first power means for rotating said shaft and cutter wheel assembly, said .cutter wheel assembly comprising a supporting plate extending transverse the shaft, at least one rotary cutting blade pivotally supported on said plate for radial movement in a plane transverse the shaft from a retracted position inside the pile through a range of cutting positions in which it contacts the pile wall to an extended position in which it has made a radial cut through said wall, a second power means for rotating said blade about its own axis in said range of positions and a third power means for moving said blade through said cutting positions, holding it in said extended position while said shaft is rotated to orbit the blade, while rotating on its axis, to completely sever the pile, and withdrawing the blade to its retracted position thereafter.

10. The pile cutter of claim 9 in which said securing means comprises a gripper block, upper and lower arms each having one end pivotally secured to said gripper block and the other end respectively pivotally secured to upper and lower collars non-rotatably mounted on said shaft, one of said collar being secured against sliding on said shaft and the other being slidable thereon, and power means for sliding said slidable collar toward said fixed collar, whereby said gripper block is moved radially outwardly to engage the inside surface of the pile.

11. A method of cutting a pile secured at one end comprising the steps of cutting through the wall of the pipe from the inside at a multiplicity of circumferential locations, such first cuts being of limited circumferential extent and being made substantially simultaneously, and thereafter orbitally cutting the wall to join the ends of said first cuts, said orbital cuts also being made substantially simultaneously.

12. A method of cutting a pile from the inside comprising the steps of making a first, radial cut outwardly from the inside surface with a rotary blade of smaller diameter than the inside diameter of the pile and making a second, circumferential cut joining the ends of the firs-t cut by orbiting the rotary blade about the pile axis while said blade is being rotated about its own axis.

13. The pile cutting method of claim 12 which includes the additional step of inserting a number of wedges in one of said cuts to prevent the blade from being pinched, said additional step preferably being performed as soon after the beginning of the second cut as space is available for the insertion of a wedge.

14. A cutter assembly for a pile cutter comprising a number of rotary cutting wheels each provided with a first power means for rotating the wheel on its own axis, a like number of wedge inserting means each provided with a second power means, means for supporting each said cutting wheel transversely of a pile in a range of radial positions between a retracted position wherein it lies between the longitudinal axis of the pile and the inner surface thereof to an extended position wherein it has cut radially through said pile While rotating about its own axis, a third power means for moving said cutting wheel between said positions and holding it in any predetermined position in such range, said second power means serving to move said wedge inserting means radially from a retracted position adjacent said cutting wheel and spaced from the inner surface of the pile to an extended position whereat it forces a wedge into the cut made by the cutting wheel and thereafter retracting said wedge inserting means, and a fourth power means for rotating said number of cutting wheels, while in said extended position and each rotating about its own axis, around said pile axis to sever said pile.

No references cited.

WILLIAM W. DYER, 111., Primary Examiner. HARRISON L. HINSON, Examiner.

Claims (1)

11. A METHOD OF CUTTING A PILE SECURED AT ONE END COMPRISING THE STEPS OF CUTTING THROUGH THE WALL OF THE PIPE FROM THE INSIDE AT A MULTIPLICITY OF CIRCUMFERENTIAL LOCATIONS, SUCH FIRST CUTS BEING OF LIMITED CIRCUMFERENTIAL EXTENT AND BEING MADE SUBSTANTIALLY SIMULTANEOUSLY, AND THEREAFTER ORBITALLY CUTTING THE WALL TO JOIN THE ENDS OF SAID FIRST CUTS, SAID ORBITAL CUTS ALSO BEING MADE SUBSTANTIALLY SIMULTANEOUSLY.

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