SELF-PROPELLED CUTTING APPARATUS

Statement Regarding Federally Sponsored Research

This work was not supported by any federally funded research.

Cross-Reference to Related Application

This application claims priority to, and the benefit of, U.S. Provisional Patent Application No. 61/005,519, filed on December 4, 2007, which is incorporated herein by reference in its entirety.

Field

This disclosure pertains to, inter alia, apparatus and methods for cutting materials, especially materials such as pipe, concrete structures, and the like that are hazardous or difficult to cut in situ using conventional methods and apparatus.

Background

Modern construction, demolition, and repair often require the in situ cutting, splitting, or rupture of massive and/or dense materials such as concrete, metal sheet, tube, and plate, pavers, pavement, tile, pipe, etc. Especially during demolition, cutting, splitting, and rupture operations tend to be uncontrolled, and frequently involve fragmentation, crushing, or bursting rather than actual cutting.

Certain demolition activities would be facilitated or enhanced if they could be performed in a controlled and effective manner. For example, full-penetration cutting of concrete and other types of flatwork could be advantageous wherever it is desired to provide a clean and consistent demolition boundary. Conventionally, this type of cutting work is performed using manually operated, walk-behind, water- cooled circular saws employing diamond-coated blades. Such saws are effective but they are slow. They also require a skillful and patient operator, especially if straight and/or long cuts are required. Another application involving cutting of massive material is the selective cutting of concrete pavement, flatwork, and other structure to form control joints for crack control and/or control of thermal expansion and contraction of the material.

Again, these cuts conventionally are made using manually operated, walk-behind, water-cooled circular saws requiring skilled operation.

Yet another application involving cutting of massive material is the post hoc formation of penetration pathways or the like in existing or just-formed concrete structures. For example, in building construction, elevated floor penetrations are often made through existing concrete for passage of electrical, mechanical, plumbing, or architectural components. These penetrations are typically made after the placement and curing of the concrete. These penetrations are conventionally formed using manually operated, water-cooled, core-drills that remove cylindrical prisms of concrete in a repetitive manner until the basic desired opening is made. The process is time-consuming, and the resulting opening is usually irregular and jagged, which usually requires that the openings be concealed or patched after the penetrating component is installed. Circular saws, as summarized above, are sometimes used for making penetrations, but the cuts typically overrun the desired penetration opening. Cut overruns tend to weaken the adjacent concrete and can impose a need for additional support to avoid excessive weakening of the overall structure. For example, it is not uncommon for an engineer to recommend additional steel reinforcement at the penetration to compensate for unintended loss of load-bearing capacity due to the cut overruns. Yet another area involving cutting of massive existing material is cutting underground pipe in preparation for rehabilitation or replacement of the pipe. The conventional approach for replacement of pipe is an "open excavation" approach that requires all soil and overburden concealing the existing pipe, as well as adjacent soil that might cave-in, be removed to allow the pipe to be extracted and replaced. This approach is time-consuming, expensive, and disruptive to surrounding areas, and is the only method currently available for replacement of Corrugated Metal Pipe (CMP), which is a common type of pipe material for sanitary sewer and storm- water sewer applications. Unfortunately, this approach is problematic for the following reasons: (1) High site disturbance. The depth of the sewer or conduit to be replaced or refurbished can exceed 20 feet at some locations. Excavations of these depths require significant lay-back of material removed from the excavated trenches. The

extent of such excavation would essentially encompass a large section of adjacent land that would have to be rebuilt along with any adjacent utilities or infrastructures that are disturbed by the activity.

(2) High cost. Deep excavations not only require more time to perform, but also require engineered shoring to prevent cave-ins. Both requirements increase project costs substantially. For example, costs to replace a 500-ft section of CMP by excavation currently exceed $250,000.

(3) Increased project schedule. Open excavation and the associated site disturbance and project complexity can increase the project duration to an unacceptable extent, due especially to the collateral impact on existing structures and activities.

To address the problems associated with open excavation of underground pipe, various less intrusive methods are available for some pipe materials such as concrete, ductile iron, plastic, etc. One approach is pipe "bursting," in which an existing pipe is essentially demolished in situ by progressive application of outwardly directed radial forces of sufficient magnitude to break the pipe. Pipe bursting is currently used for the replacement or rehabilitation of pipe lines for sanitary sewer, storm sewer, domestic water, gas, etc. Bursting is performed by inserting a bursting "head" or "mandrel" into a pipe and mechanically driving the mandrel through the pipe by various methods. The bursting "head" or "mandrel" expands, splits, and fragments the pipe as it progresses, leaving a cavity that is at least as large as the demolished pipe. A new pipe is pulled behind the progressing bursting head, simultaneously installing a new pipe to replace the demolished pipe. The remnants of the existing pipe are typically left in place, having been expanded into the surrounding substrate.

Some advantages of pipe bursting include lower cost, decreased project duration, and substantially reduced site disturbance. Pipe bursting currently seems to work better on pipe made of concrete, cast iron, or other relatively non-ductile material. Concrete pipe, for example, is strong in compression but relatively weak in radial expansion and hence amenable to bursting. But, substantial difficulty is experienced in applying conventional pipe-bursting methods to pipe made of relatively ductile materials, such as Corrugated Metal Pipe (CMP). CMP is widely

used for sewer and drainage conduits, which are typically constructed by coupling pipe segments end-to-end using metal bands. Due in part to its corrugated wall structure and in part to the ductile nature of the steel usually used for fabricating CMP, this type of pipe is very difficult to burst. Specialized bursting heads and mandrel devices have been considered for use in bursting CMP. The idea is to provide these devices with multiple "splitting" blades that are thrust outward through the wall of the pipe in a repetitive action as the bursting head progresses in the lumen of the pipe. The intent is to stretch the pipe apart by ripping or tearing as opposed to the conventional approach used for most other non-ductile pipe materials where the pipe breaks up by radial expansion. However, this conventional bursting approach has been unsuccessful with CMP, due in part to the radial stretchability of CMP, as noted above. Another major difficulty is the tendency of the metal band elements, which connect adjacent CMP pipe segments together, to detach from their original positions and accumulate (stack up) ahead of the mandrel. Even a few stacked-up bands are simply too strong to burst or split.

Alternative technologies are available to rehabilitate the structural integrity or increase the conveyance capacity of CMP without having to remove or destroy the existing CMP. In one approach (e.g., INSITUFORM), a high-density polyethylene (HDPE) liner or similar material is everted inside the existing CMP pipe and cured to form a liner inside the pipe. This approach slightly reduces the diameter of the pipe but provides a lower friction or "slicker" inside pipe wall that can significantly increase flow rate through the pipe compared to previously. This is a proven and effective technology but is limited by the diameter of the existing CMP pipe, and as such may not increase the flow rate enough to meet design requirements.

Summary

Difficulties with conventional cutting apparatus and methods are addressed by apparatus and methods as disclosed herein.

According to one aspect of the invention, cutting apparatus are provided. An embodiment of such an apparatus comprises a frame, to which are mounted at least

one cutting device and a locomotion device. The apparatus also includes a control device coupled to the locomotion device and to the cutting device. The control device is configured to controllably actuate the cutting device to apply a cutting force to a target material and to actuate the locomotion device to move the apparatus relative to the target material. Here, "target material" can be, for example, a wall, a paved surface, a structural member, indigenous earth surface or underlying mass such as rock, or the inside surface of a pipe or analogous structure. The apparatus desirably is self-propelled, and propulsion of the apparatus can be partially or completely controlled by a human situated at a remote location relative to the apparatus. The apparatus is particularly suitable for in situ cutting in locations that cannot be easily or readily accessed by a person, or in situations that would be hazardous to nearby persons. The cutting device also can be remotely controlled, including timing and location at which cutting energy is applied, which can be performed during locomotion of the apparatus. In certain embodiments the cutting device comprises first and second fluid- jet cutters directed to apply respective cutting forces on opposing sides of the frame. Placing the cutters in this manner offsets reaction forces applied to the apparatus as high-pressure cutting fluid is discharged from the cutters. The cutters desirably are remotely controlled with respect to turning them on and off and/or with respect to positioning the cutters relative to surfaces to be cut by them. For positioning the cutters, the apparatus can include respective positioning devices mounted to the frame and to which the first and second fluid-jet cutters are mounted, wherein the positioning devices providing at least extension and retraction of the respective fluid-jet cutters. For many applications the locomotion device desirably comprises first and second motor-driven track assemblies. Certain embodiments having this feature desirably include camber-adjustable mountings coupling the track assemblies to the frame. The mountings allow changes to be made to the camber of the track assemblies to ensure consistent and proper positioning of the apparatus in the lumen of a pipe as the apparatus moves longitudinally in the pipe.

The apparatus desirably further comprises a monitoring device mounted to the frame. The monitoring device can be a camera, a lamp, a position sensor, an

atmosphere sensor, a temperature sensor, a pressure sensor, or an image sensor, or combinations of these. One or more cameras are particularly desirable, especially for use of the apparatus inside the lumen of a pipe. Camera use may require an illumination device mounted to the frame and operable to provide illumination for the camera(s). Cameras and other monitoring devices can be used to provide data that can be used in a feedback-control manner (e.g., by a human operator) for controlling motions of the apparatus.

Remote-controlled apparatus desirably are connected via an umbilicus to a control station. The umbilicus can include multiple hoses and/or cables that supply, as required, power and cutting media to the apparatus, as well as provide control commands to the apparatus while returning data from the monitoring device to the control station.

According to another aspect of the invention, cutting systems are disclosed. An embodiment of such a system comprises a cutting apparatus including a frame to which are coupled at least one cutting device, a locomotion device, and a monitoring device, as summarized above. The system also includes a control station coupled remotely to the locomotion device and the cutting device. The control station is configured to controllably actuate the cutting device to apply a cutting force to a target material and to actuate the locomotion device to move the apparatus relative to the target material, based on data provided by the monitoring device. The control station can be further configured to actuate the locomotion device as the cutting device is applying the cutting force. The control station is operated at least in part by a person, based at least in part on data from the monitoring device. The control station can be located at an operation base coupled via an umbilicus to the cutting apparatus. The operation base can include at least one of a computer coupled to the control station, a supply of cutting medium deliverable by the umbilicus to the cutting devices, a video monitor coupled to the monitoring device, and a power supply for the locomotion device.

According to another aspect of the invention, methods are provided for cutting a pipe in situ along an inside wall of the pipe. An embodiment of the method comprises self-propelling a cutting apparatus inside the pipe along the inside wall of the pipe. The cutting apparatus is actuated to apply cutting energy to the wall of the

pipe. Meanwhile, monitoring is performed of at least one of locomotion and cutting being performed by the cutting apparatus. The steps of self-propelling, actuating, and monitoring desirably are performed by remote control. Monitoring can include illuminating a portion of the pipe wall during application of cutting energy to the pipe wall and obtaining an image of the illuminated portion. Based on the image serving as feed-back, at least one of self-propelling and actuating is controlled, desirably by a person. Cutting of the pipe can be followed by pipe bursting.

Another aspect is directed to methods for cutting a material in situ along a wall of the material. An embodiment of the method comprises self-propelling a cutting device along the wall of the material, actuating the cutting device so as to apply cutting energy to the wall as the cutting device is being self-propelled, and navigating the cutting device as the cutting device is being self-propelled. The method also includes remotely controlling movement of the cutting device and application of the cutting energy as the cutting device is being self-propelled. The foregoing and additional features and advantages of the invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings.

Brief Description of the Drawings FIG. 1 is a rear isometric view of a representative embodiment of the subject apparatus, with cutting devices extended.

FIG. 2 is a front-end view of the apparatus embodiment situated in the lumen of a pipe, with cutting devices extended.

FIG. 3 is a rear-end view of the apparatus embodiment situated in the lumen of a pipe, with cutting devices extended.

FIG. 4 is a right-side elevational view of the apparatus embodiment situated in the lumen of a pipe, with cutting devices extended.

FIG. 5 is left-side elevational view of the apparatus embodiment situated in the lumen of a pipe, with cutting devices extended. FIG. 6 is a top view of the apparatus embodiment, with cutting devices extended.

FIG. 7(A) is an isometric view of two fluid-jet cutters mounted to a positioning device operable to extend and retract the cutters. In this figure, the cutters are shown retracted.

FIG. 7(B) is an isometric view corresponding to FIG. 7(A), but with cutters extended.

FIG. 8 is an isometric view of a complete cutting system including the apparatus embodiment and supporting equipment and controllers.

FIG. 9 is a dimetric view of an embodiment of a primary control station used with the system shown in FIG. 8. FIG. 10(A) is an isometric view of a pivot plate by which the track assemblies are mounted to the frame of the apparatus embodiment of FIG. 1.

FIGS. 10(B)-IO(D) are diagrams showing zero camber, moderate camber, and substantial camber of a track assembly, respectively, to illustrate the automatic placement of a proper mounting hole for the pivot plate. FIG. H(A) is a side elevational view of an apparatus according to an alternative embodiment, in which the frame comprises two frame portions having a certain degree of independent movability relative to each other.

FIG. H(B) is a wire-diagram depiction of the second frame portion in the embodiment of FIG. H(A).

Detailed Description

Specific manifestations of this invention are provided herein as illustrations and are not intended to limit the scope of the invention, as various modifications will become apparent to one skilled in the art. As used in this application and in the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Additionally, the term "includes" means "comprises." Further, the term "coupled" encompasses mechanical as well as other practical ways of coupling or linking items together, and does not exclude the presence of intermediate elements between the coupled items.

The things and methods described herein should not be construed as being limiting in any way. Instead, this disclosure is directed toward all novel and non-

obvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The disclosed things and methods are not limited to any specific aspect or feature or combinations thereof, nor do the disclosed things and methods require that any one or more specific advantages be present or problems be solved.

Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed things and methods can be used in conjunction with other things and method. Additionally, the description sometimes uses terms like "produce" and "provide" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms will vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art.

In the following description, certain terms may be used such as "up," "down,", "upper," "lower," "horizontal," "vertical," "left," "right," and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an "upper" surface can become a "lower" surface simply by turning the object over. Nevertheless, it is still the same object. The current problems in achieving controlled cutting of flatwork, pipe, and the like are addressed by self-propelled cutting apparatus and methods, as disclosed herein. The disclosed apparatus and methods provide, inter alia, more powerful, precise, complete, and controlled cuts, whether full-depth or partial-depth. Making of cuts, using the apparatus, in pipe can be followed by use of a pipe burster, in which the cuts made by the apparatus yield more controlled and predictable bursts. The cuts in pipe also enable pipe bursting to be performed under conditions and on types of pipe not possible heretofore.

Various embodiments of the subject apparatus and methods have particular applicability for preparing pipe for subsequent bursting. The embodiments are particularly useful for preparing burst-stubborn pipe such as CMP. The apparatus and methods also can be used for tasks other than preparing pipe for bursting. For example, various embodiments can also be used for cutting any of various types of material other than pipe, including but not limited to flatwork, pavement, earth, etc. In general, an embodiment of the apparatus is placed relative to the material to be cut {e.g., placed in the lumen of a pipe). The apparatus is self-propelled and hence is movable relative to the material while the apparatus performs a controlled cutting or scoring of the material. Thus, cutting can be performed in situ. When the apparatus is placed to move and make cuts inside the lumen of a pipe, the resulting controlled cutting and/or scoring of the pipe walls can provide the pipe with bursting loci situated at appropriate locations inside the pipe. Then, when a bursting device or mandrel is subsequently introduced into the pipe, the pipe is readily and easily burst along the bursting loci in a controlled and consistent manner. Since the apparatus is self-propelled, the bursting loci can be provided inside a pipe of unlimited length.

Attention is now directed to FIGS. 1-4 depicting respective views of a representative embodiment of a self-propelled cutting apparatus 10. FIG. 1 is an isometric view, and FIGS. 2-4 are a front view, rear view, and right-side view, respectively. The apparatus 10 comprises a frame 12, a locomotion device 14 mounted to the frame, and at least one on-board cutting device 16 mounted to the frame 12. The apparatus 10 also comprises an on-board illumination device 18 {e.g., one or more lamps) and an on-board monitoring device 20 {e.g., one or more cameras). For general use, including use inside a pipe, the locomotion device 14 comprises multiple wheel or track assemblies 22 that propel the apparatus 10. The locomotion device 14 is driven using one or more electric motors (respective electric motors are included, but not shown, in the track assemblies 22). Alternatively, hydraulic motors can be used. Electric power can be supplied to the locomotion device 14 via an umbilicus 28 coupling the apparatus 10 to a remote station including a power source. Alternatively or in addition, the apparatus 10 can include one or more on-board batteries (not shown) for supplying power. The cutting

devices 16 are mounted to a positioning device 24, mounted to the frame 12, that is operable, inter alia, to extend the cutting devices 16 to respective cutting positions and to retract the cutting devices 16 when they are not being used for cutting. The positioning device 24 is driven by a motor 26. The cutting devices 16 can be configured to perform cutting and/or scoring by any of various methods, including laser cutting, liquid-jet cutting, plasma-arc cutting, or other suitable technique.

The umbilicus 28 also includes one or more cables that conduct controlled driving commands to the locomotion device 14 to achieve the desired motion {e.g., velocity, starting and stopping, reversing) of the apparatus 10. The umbilicus 28 also delivers and sends other control commands such as, but not limited to, commands to the illumination device 18 and to and from the monitoring device 20 to provide visual and other feedback of locomotion and cutting, and commands for extension and retraction of the cutting devices. Velocity of locomotion can be controlled based on, inter alia, the rate at which desired cut(s) can be made in the particular material being cut. For example, one velocity may be selected for moving the apparatus 10 to a desired start location, and another velocity may be selected for moving the apparatus forward as it is performing cutting. As required, the umbilicus 28 also supplies electrical power to the cutting devices 16, to the illumination device 18, and to the monitoring device 20. Also, if required, the umbilicus 28 supplies cutting medium {e.g., water and abrasive grit) to the cutting devices 16. Also, if required, the umbilicus supplies compressed air to the cutting devices for turning the cutting devices on and off.

Many embodiments of the apparatus 10 are particularly configured for use inside a pipe 40, as a prelude to pipe bursting for example, to form burst loci 42 (cuts or scores) inside the pipe in a controlled and consistent manner. The burst loci 42 can be continuous or discontinuous, depending upon the particular pipe 40, and can be, for example, extended cuts into the side wall of the pipe. The cuts desirably are of sufficient depth to penetrate the wall thickness of the pipe (FIG. 2) or alternatively only through a portion of the thickness, depending upon the types of cutting devices employed and the particular depth desired. In many applications, the cuts are full depth, meaning that the cuts fully penetrate at least the thickness of the pipe wall. In other situations the cuts may be only partial depth. For example, the

apparatus 10 can be configured to perform one or more full-depth cuts or "score" cuts (partial depth cuts), in a consistent and controlled manner, along the length of a pipe interior. The apparatus 10 desirably comprises multiple cutting devices 16, allowing the apparatus to make multiple cuts simultaneously such as on both sides of the apparatus 10 and/or above and below the apparatus.

In many embodiments the locomotion device 14 comprises first and second track assemblies 22 for self-propelled locomotion. In alternative embodiments the locomotion device 14 comprises first and second sets of wheels (not shown). Each track assembly 22, for example, is actuated by at least one respective electrical or hydraulic motor (not detailed). Providing respective motor(s) for each track assembly 22 allows independent control of the track assemblies, as may be required to ensure the apparatus 10 moves along a desired course, including trajectory corrections, turning, etc. If the locomotion device 14 comprises first and second sets of wheels, at least one wheel in the each set desirably is a driven wheel coupled to a respective motor. Control of the locomotion device 14 can be achieved by any of various means. For example, the motors thereof can be connected to and driven by respective control circuits {e.g., at an operator control station) that modulate the current and/or voltage being delivered to the motors.

Relative to the frame 12, the track assemblies 22 (or wheel sets) are manually, controllably, or automatically adjustable to facilitate their proper orientation for the prevailing setting in which the apparatus 10 is moving and being used. For example, the track assemblies 22 may need to be in a cambered orientation for use of the apparatus 10 inside a pipe 40. (For example, FIG. 2 shows the track assemblies 22 cambered to align approximately with respective radii of the pipe 40). Proper camber inhibits the apparatus 10 from creeping up the inside wall of the pipe 40 as the apparatus travels longitudinally in the pipe. For use on a substantially planar surface, the track assemblies 22 need not be cambered.

In the embodiment shown in FIGS. 1 and 3, camber is achieved by mounting the track assemblies 22 on respective pivot plates 30. Each pivot plate 30 includes multiple positioning holes 31 that are selectively engaged with a respective pin 32 on the frame 12. By selecting the appropriate positioning hole 31, the camber of the

respective track assembly 22 is adjusted. This "selection" in this embodiment is automatic, as described later below.

Whereas the apparatus 10 functions well with two track assemblies 22, it can have more than two track assemblies. For example, the apparatus can have three track assemblies, two lateral ones as shown and a third track assembly oriented upside-down on an upper frame member to engage the top interior surface of the pipe as the apparatus travels in the pipe.

Each on-board cutting device 16 desirably comprises a respective fluid-jet cutting head 50 that discharges a high-pressure stream of fluid cutting medium to the cutting locus. The fluid cutting medium comprises high-pressure water and abrasive grit suspended in the water. Abrasive grit enters the head 50 at a side fitting 45 and high-pressure water enters the head 50 at a rear fitting 46 (FIG. 1). The stream of high-pressure water is turned on and off by a controlled stream of compressed air entering a top fitting 47. When turned on, the heads 50 discharge the fluid cutting medium at extremely high pressure (e.g., 30,000 to 50,000 psi), which is usually sufficient to penetrate fully through the wall thickness of pipe or construction material (and well into the surrounding soil or other medium). An advantage of full- penetration cutting is that much of the debris (grit, steam, and water droplets) discharged by the cutting head 50 as well as much of the material debris generated as the material is being cut pass through the cut to the other side (e.g., outside the pipe 40). This allows the atmosphere in the vicinity of the monitoring device 20 (e.g. , inside a pipe) to remain relatively light in suspended matter as cutting is being performed, which greatly facilitates use of the monitoring device 20. Further clearing of the atmosphere inside a pipe 40 can be achieved, if necessary, by placing a fan or blower at one end of the pipe to pull fresh air into the pipe during cutting (see FIG. 8).

As noted, the cutting devices 16 in this embodiment are mounted on respective adjustable positioning devices 24 that enabling the cutting devices to be oriented and positioned as desired, including full extension for cutting and full retraction when not being used for cutting. (It will be understood that positioning devices 24 are particularly useful if the cutting devices are fluid-jet cutting heads or plasma-arc cutters. Other types of cutting heads, such as lasers, may not require

positioning devices.) The positioning devices 24 are desirably actuated using an electric motor 26 mounted to the frame 12. The motor 26 is coupled to a pivot plate 33 to which are coupled respective linking arms 34 that, in turn, are coupled to the respective cutting devices 16. Rotation of the pivot plate 33 by the motor 26 imparts lever forces to the linking arms 34 and thus to the cutting devices 16, as discussed in more detail later below.

In most embodiments of the apparatus 10 in which the cutting device 16 is a fluid-jet cutting head, the apparatus desirably includes multiple fluid-jet cutting heads 50 as shown, for example, in FIGS. 1, 3, and 4. The fluid-jet cutting heads 50 desirably are used simultaneously on opposite sides of the apparatus. A fluid-jet cutting head 50 discharging a high-pressure stream of cutting medium in one direction experiences a substantial reaction force in the opposite direction. Using two fluid-jet cutting heads 50, for example, that discharge respective streams of cutting medium simultaneously on both sides of the apparatus offsets the reaction forces on the apparatus 10. In FIGS. 1, 3, and 4, the fluid-jet cutting heads 50 are oriented 90° apart, each being 45° from the longitudinal axis (front to back) of the apparatus. Alternatively, for example, the cutting heads can be oriented 180° from each other, from opposing sides of the apparatus, and thus 90° from the longitudinal axis. Other angles are also possible. Other embodiments utilize more than two cutting devices 16.

Alternatively, for example, the on-board cutting device 16 can be a laser cutter or plasma-arc cutter. An advantage of using a laser cutter is that the cutter does not experience significant reaction force, which alleviates having to balance reaction forces acting on the apparatus 10. The lack of significant reaction force can allow the apparatus to have only one cutting device, or only one cutting device operating at a given time.

As noted, a fluid-jet cutting head 50 comprises a first inlet 46 for high- pressure liquid (usually water), a second inlet 45 for a stream of abrasive grit (e.g., garnet), and a third inlet 47 for compressed air. These materials are supplied from an operator control station by respective hoses 54, 56, 58 of the umbilicus 28 extending from the control station to the apparatus 10. In other words, the umbilicus 28 connects the apparatus 10 to the control station, which provides, inter alia, the

streams of liquid, grit, and air to the umbilicus and hence to the apparatus 10. The cutting head 50 also includes a mixing tube (not shown) in which the streams of liquid and grit are mixed. The mixture is discharged through a nozzle 52 that, when the cutting head is in the extended position, is situated near the surface to be cut. The nozzle 52 can be surrounded by a spray shield (not shown) if desired. For maximum cutting force, the nozzle 52 is situated close to the surface during cutting. If the cutting device 16 is a laser, then power for the laser can be delivered to the apparatus 10 by a power cable included with the umbilicus 28. If the cutting device 16 requires a supply of cutting gas(es), then respective hoses can be included with the umbilicus 28 for delivery of the gas(es) from an operator station.

The umbilicus 28 also typically includes at least one primary control cable 36 conducting electrical power to the apparatus and an auxiliary control cable 37 (FIG. 1) conducting control commands and data back and forth between the apparatus 10 and the control station. The monitoring device 20 can comprise, for example, at least one video camera. Desirably, at least two cameras are used, with respective cameras being directed at least to opposite sides of the apparatus. For example, the cameras can be directed to obtain images at or or near the vicinity of a cut being made by the respective cutting device 16. The monitoring device 20 is useful for various tasks including, but not limited to, monitoring forward and reverse locomotion of the apparatus 10, determining location of the apparatus, visualizing obstructions, monitoring cutting to be performed or being performed by the cutting device 16, and monitoring cuts that have already been made. The monitoring device 20 can be configured to respond to visible light or infrared light, for example. This light can be as supplied by the illumination device 18 and/or as provided by indigenous light (if any) at the cutting site. The illumination device 18 desirably includes multiple lamps (e.g., LED lamps), desirably at least one lamp illuminating each lateral side of the apparatus 10. In alternative embodiments, the monitoring device can be selected from: camera, position sensor, atmosphere sensor, temperature sensor, pressure sensor, GPS sensor, and image sensor, and combinations thereof.

In FIGS. 1-4 the umbilicus 28 terminates at an umbilical/hose mounting plate 44 at which each of the hoses 54, 56, 58 and cables 36, 37 are connected to on-board

hoses and cables (not shown). For example, the hoses 54, 56, 58 are connected to respective on-board hoses delivering water, abrasive grit, and air to the fluid-jet cutting heads 50. These on-board hoses, mounted as appropriate to the frame 12, desirably have sufficient flexibility to accommodate extension, retraction, and positioning motions of the cutting heads 50 as performed by the positioning devices 24. Similarly, the on-board cables to which the cables 36, 37 are connected are mounted as appropriate to the frame 12 and are connected to, for example, the track assemblies 22, the monitoring device 20, the illumination device 18, and the motor 26. FIG. 5 is a left-side view of an embodiment of the apparatus 10 showing the illumination device 18 (in the form of respective LED lamps for the left and right sides of the apparatus) and monitoring device 20 (in the form of respective cameras for the left and right sides of the apparatus).

FIG. 6 is a top view of an embodiment of the apparatus 10 showing details of the positioning device 24, notably the pivot plate 33 and linking arms 34. The monitoring device 20 of this embodiment comprises three cameras, namely a leftside camera, a right-side camera, and a front ("navigational") camera. Also shown is the illumination device 18 comprising a left-side lamp and a right-side lamp.

Details of the positioning device 24 are shown in FIGS. 7(A)-7(B), which shows the fluid-jet cutting heads 50 in retracted and extended positions, respectively. Each cutting head 50 is slidably mounted on a respective sled 60 that is movable along a respective guide track 62. The guide tracks 62 are rigidly mounted to the frame 12, and the sleds 60 are mounted to respective linking arms 34. The linking arms 34, in turn, are pivotably mounted to the pivot plate 33. When the pivot plate 33 is rotated by the motor 26 (not shown, but see FIG. 6), the linking arms 34 apply respective sliding forces to the sleds 60 relative to the guide tracks 62 to either extend or retract the heads 50. The heads 50 are biased by springs 64.

As noted, the apparatus 10 is coupled via the umbilicus 28 to an operator control station, usually located at a "base station" 100, as shown in FIG. 8. The base station 100 can be situated upstream of the region to be cut. FIG. 8 depicts the base station 100 located at or near an upstream ("entry") manhole 102 coupled to and providing access to the pipe 104 to be cut. Note that the pipe 104 is depicted as

CMP. Thus, the apparatus 10 moves away from the entry manhole 102 and operation base 100 during cutting of the pipe 104. Alternatively, the operation base 100 can be situated downstream of the region to be cut, in which the apparatus 10 moves toward the operation base during cutting. The depicted base station 100 includes a trailer 106 or the like which is useful in inclement weather and for transporting and housing various pieces of equipment. The trailer 106 is placed near an opening 108 for the entry manhole 102. Around the manhole opening 108 is placed a sleeve-like guide 110 for protecting and guiding the umbilicus 28 into the manhole 102. The exemplary base station 100 shown is for use with an apparatus 10 configured to perform fluid-jet cutting of the pipe 104. To such end, the operation base 100 includes a UHP pump assembly 112 for supplying a high-pressure stream of water to the apparatus 10. The UHP pump assembly 112 is electrically powered via a power line 114 delivering electrical power from an external source. The UHP pump assembly 112 is supplied by water via a hose 116 connected to an external source. The power line 114 and water hose 116 are connected to a front panel 118 of the UHP pump assembly 112. The power line 114 can be supplied by power from a general power line 120 supplying power to the trailer 106. The trailer 106 is also connected to a general water- feed line 121. For supplying compressed air to the apparatus 10 (for, e.g., turning the cutting heads on and off), the trailer 106 houses an air compressor 122 that runs off trailer power. The air compressor 122 is connected via an air hose 124 (included in the umbilicus 28) to the apparatus 10. For supplying abrasive grit to the apparatus 10, the trailer 106 also houses a fluidized abrasive hopper 126. The hopper 126 is connected via a grit-supply hose 128 (included in the umbilicus 28) to the apparatus 10. Air from the air compressor 122 can also be used for supplying air to an "abrasive amplifier assembly" (not shown) connected between the hopper 126 and the apparatus 10 to ensure a steady stream of abrasive grit from the hopper 126 to the apparatus 10. The trailer 106 also houses a control station 130 (for performing primary and auxiliary control of the apparatus 10) that is powered by trailer power and that is connected to the apparatus 10 via primary and auxiliary control cables 132, 134,

respectively (included in the umbilicus 28). The trailer 106 also houses a display monitor 136 and a DVD recorder and video processor 138.

After entering the manhole opening 108, the umbilicus 28 descends into the manhole 102, supported by an umbilicus sleeve 140. To avoid applying excessive stress to the umbilicus 28, the sleeve 140 is supported by a chain 142 or the like suspended from the sleeve 110. From the sleeve 140, the umbilicus 28 proceeds to the apparatus 10 to which the umbilicus is connected, as described earlier above.

For lowering the apparatus 10 into the entry manhole 102, a hoisting gantry 144 desirably is used. The apparatus 10 travels in the pipe 104 downstream to an exit manhole 146 from which the apparatus 10 can be removed if desired (again, using the gantry 144). To continue further with cutting downstream of the "exit manhole" 146, the operation base 100 can be moved to the manhole 146, which is now used as a new entry manhole. The surface opening 148 of the exit manhole 146 can be fitted with a ventilation duct 150 connected to a ventilation fan 152 powered by a portable generator 154. The fan 152 helps keep the atmosphere in the pipe 104 from becoming excessively laden with particles and droplets, which otherwise could interfere with functioning of the monitoring device 20.

During cutting, water may accumulate in the pipe 104. If necessary or desired, the depth of such water can be controlled using a bladder-style pipe stopper (not shown) in the downstream exit pipe 156.

Turning now to FIG. 9, an exemplary primary and auxiliary control station 130 is shown. Desirably, the control station 130 is housed in a weather-proof case 202. Power is supplied to the control station 130 via a power supply plug 204 and on-off switch 206 (power on being indicated by an indicator lamp 208). Input ports 210, 212 (e.g., RCA style) receive data input from respective cameras on the apparatus 10. Control of the apparatus 10 can be by pod or joystick, selectable by a switch 214. The station 130 includes a joystick 216 used for manual control of locomotion of the apparatus 10. Feedback for control is provided to an operator by the display monitor 136. For pod control, controls 218, 220 are provided for speed and balance, respectively. The control station 130 also includes on-off switches 222, 224 and dimmer controls 226, 228 for respective lamps on the apparatus 10. Data

communication to and from the apparatus and control station 130 is via the primary and auxiliary cables (of the umbilicus 28) connected to the multi-pin connector 230. Details of camber adjustment are shown in FIGS. 10(A)-IO(D). FIG. 10(A) depicts a pivot plate 30 by which the track assemblies 22 are mounted to the frame 12 of the apparatus 10. As described above, two pivot plates 30 are used per track assembly 22. As thus mounted, the track assembly 22 will swing or rotate such that the center of gravity (CG) for the track assembly approximately aligns vertically with the positioning hole 31 that should be used. As such, the positioning hole selection determines the neutral camber angle of the track assemblies (the angle at which the track assembly is oriented, relative to vertical, when no unbalanced lateral forces are acting upon it). The neutral camber angle also determines the neutral position of the apparatus 10 inside a pipe. As momentary incidental lateral forces (from unbalanced cutter thrust forces, drag forces on the umbilicus, irregularities in the pipe surface, etc.) cause migration of the apparatus 10 from the neutral position, gravitational forces will return the track assemblies to their neutral positions, and hence return the apparatus to its neutral position inside the pipe. FIG. 10(B) depicts a zero camber angle, suitable for locomotion of the apparatus 10 on a somewhat to substantially flat surface or in a pipe having an extremely large diameter. Note the particular positioning hole 31 automatically selected. FIG. 10(C) depicts a moderate camber angle, suitable for locomotion of the apparatus 10 in a pipe having large diameter. Note the particular positioning hole 31 automatically selected. FIG. 10(D) depicts a large camber angle, suitable for locomotion of the apparatus 10 in a pipe having small diameter. Note the particular positioning hole 31 automatically selected. In all three figures, "CG" is center of gravity. The apparatus 10 can include an on-board balance sensor to determine when the apparatus is not level (laterally tilted) or otherwise not at a desired angular disposition in the pipe, as may occur as the apparatus progressing down a pipe begins to crawl up a wall. Upon sensing departure from level, a feedback loop including the balance sensor triggers appropriate adjustments to the movement rate of one track mechanism relative to the other track mechanism to restore the apparatus to level. Alternatively, camber adjustment can be automated and made responsive to the on-board balance sensor.

Configurational modifications can be implemented to, for example, increase track stability and/or optimize the track-contact patch. Additionally, modifications may be implemented to increase the range of pipe sizes with which the apparatus 10 can be used. Other modifications may include modification of the cutting device(s) 16 to operate at different pressures (tailored for cost and/or the particular pipe).

Use of the apparatus 10 is not limited to cutting pipe. The apparatus 10 can be used for substantially any application that is accessible by the apparatus. The apparatus 10 is not limited to performing one-dimensional cuts. Being self- propelled, the apparatus 10 can perform cuts in at least two dimensions. Multi- dimensional cuts are facilitated by mounting at least one cutting device 16 to the frame 12 using an adjustable mounting enabling the cutting device to move or reorient relative to the frame. Hence, the apparatus 10 can be used, for example, for horizontal surface demolition work of materials including concrete slab and pavement, stone, glass, asphalt, plastic, metal, composite, etc. The apparatus 10 also can be used on surfaces of these materials that are not horizontal. For example, in a demolition project in which vertical concrete walls are being dismantled, the dismantled walls can be cut on-site, using the apparatus, to form pavers or the like. The apparatus 10 also can be used to form post hoc control joints for control of cracking and other collateral compromises of nearby structure, especially as otherwise would be caused by thermal expansion and/or contraction of the material. In pipe, the apparatus 10 is particularly suitable for performing longitudinal cutting of the pipe wall. The resulting cuts can serve as pre-cuts for subsequent pipe bursting. Use of the apparatus in ductile and resilient pipe such as CMP prepares the pipe for conventional bursting in a controlled and predictable manner. Thus, risks normally associated with attempting to burst CMP in situ by conventional means or to replace CMP by excavation are substantially reduced. For example, initiating a project with a conventional pipe-bursting approach that is unsuccessful can be catastrophic in view of the investment and commitment in equipment, training, and time needed to initiate the pipe bursting process. Subsequently being compelled to perform a full excavation leads to severe budgetary, schedule, and project-duration consequences and delays. Use of the current apparatus substantially reduces these risks.

Inside pipe, the apparatus 10 also can be used for severing roots and other obstacles inside the pipe. The apparatus also can be used for a similar purpose with respect to locations outside of pipe, such as (but not limited to) underground utilities, structure foundations, and paver installations. For example, when directed to a soil surface, a cutting device comprising a high-pressure fluid jet (e.g., water jet either with or without entrained particulates) can form a deep, planar slice extending depthwise many feet into soil. The slice can be nearly imperceptible at the surface. Thus, roots and the like that might eventually break into sewer conduits or undermine a foundation can be cut during a preventative maintenance activity to avoid later damage.

The apparatus 10 also can be used for precutting prior to excavation and trenching operations where rock or the like is present. For example, a trenching operation may be halted due to an encounter with a rock layer or large rock in the soil strata. In such an instance, the apparatus can be used to form cuts through the rock along each side of the excavation boundary to allow the excavation and trenching operation to continue.

The apparatus 10 also can be used in any of various emergency demolitions such as (but not limited to) situations in which victims are trapped in confined regions or under fallen debris. The precise nature and high energy of cutting performed by the apparatus may assist in extricating the victims.

The apparatus 10 can include a remote and computer-controlled navigation device and/or feed-back sensors. The apparatus can include an on-board control device such as a processor that can be responsive to external commands or programmed to perform cutting of a particular target material in a particular manner at a particular rate under particular conditions. Such programming can be performed before actual use of the apparatus. An on-board control device can be configured to cause the apparatus 10 to form a pre-programmed cut that starts at a predetermined point, follows a pre-programmed path, and stops at a desired pre-programmed point, all in one continuous, automatic operation and without overrun of the cut. The control device can also be programmed to provide accurate and consistent cutting of more complex shapes such as circles and polygons. The ability to cut more complex shapes in rapid succession provides the ability to cut desired openings in walls,

floors, and ceilings, for example, to form architectural design elements in such locations.

In the embodiment of FIGS. 1-4 discussed above, the frame 12 is rigid, and the locomotion device 14 is mounted to the frame. The locomotion device 14 in that embodiment is configured as a pair of track assemblies 22 that, as a result of the pivot plates 30 and pins 32, have some freedom of motion relative to the frame. Nevertheless, if the apparatus under locomotion encounters an obstacle over which the locomotion device 14 must travel, the frame 12 (to which the cutting devices 16 are mounted) moves upward accordingly, thereby shifting the cutting locus. After the apparatus passes over the obstacle, the cutting locus shifts back down. This interruption of the cutting locus may be undesirable.

In an alternative embodiment 300 shown (in a pipe 301) in FIGS. H(A)- H(B), the frame includes a first (outer) frame portion 302 and a second (inner) frame portion 304 (the frame portion 304 being shown shaded for clarity). The second frame portion 304 is mounted to the first frame portion 302 by a pivot axis 306 allowing the second frame portion 304 a certain freedom of motion (mainly up and down) relative to the first frame portion 302. The cutting devices 308 are mounted to the second frame portion 304, and the locomotion device (here, track assemblies 310) is mounted to the first frame portion 302. Hence, the second frame portion is a cutter-support subframe, and the first frame portion is a drive subframe. The track assemblies 310 are mounted to the first frame portion 302 in the same manner as in the embodiment of FIGS. 1-4. The pivot axis 306 desirably is located at or near the rear of the first frame portion 302. The second frame portion 304 also includes a pair of wheels 312 (see wire-frame diagram in FIG. H(B)). By this pivot mounting, the second frame portion 304 can move, especially vertically, independently of the first frame portion 302. For example, whenever the apparatus 300 encounters an obstruction, the second frame portion 304 can "float" upward, at least to a limited extent, and settle back down independently of the first frame portion 302. This allows the first frame portion 302 to climb up over the obstruction independently of the second frame portion 304, and allows the cutting devices 308 to continue cutting without influence or interruption from the positions assumed by the first frame portion 302 as it negotiates the obstacle. The leading point 314 of the

second frame portion 304 can include at least one wheel 316 to ease interactions of the apparatus (especially the second frame portion 304) with obstacles. The second frame portion 304 can also include a low-friction contact pad 318 situated lower than the wheel 316 also to ease interactions of the apparatus with obstacles. The first frame portion 302 can include a stop bar 320 to limit down motion of the second frame portion 304.

Example

The following example pertains to an exemplary apparatus that was constructed and tested. These data are not intended to be limiting in any way.

Table 1. Basic Apparatus Specifications

Table 2. Components of On-Board Cutting Device

Table 3. Base Station Components

Table 4. Components of Locomotion Device

Description (Qty) Part Specifications

Tracks Depth Rating: 30 m / 0-100 ft

(2) Speed, Load Dependent: 10+ m / 0-32 ft/min

Pull Rating: 23 kg / 50 lbs per track

Payload Capacity: 46 kg / 100 lbs per track

Tablt ; 5. Components of Monitoring Device

Description (Qty) Par t Specifications

Splash Cam Delta Camera Specifications:

Vision Industrial Color NTSC Composite Video (PAL image.

Underwater Video Optional)

Camera Auxiliary Lighting: Ultra Intense White LED's

(3) Resolution: 420 TV Lines

Focus: Fixed 1 inch to focal infinity

Lens: 3.6mm Wide Angle

Iris: Electronic

Operating Temp: -10 to 55 C

Light Sensitivity: 0.5 lux

Input Voltage: 12 VCD

Current

27O mA Consumption:

Composite Video / Female RCA

Output Signal: Jack

Physical Specifications

Body: Stainless Steel

Exterior: Stainless Steel

Camera Head

2.3 lbs in air / 1.5 lbs in water Weight:

Standard: 800 feet / Upgrade:

Depth Rating: 2000 feet

Whereas the invention has been described in connection with representative embodiments, it will be understood that it is not limited to those embodiments. On the contrary, it is intended to encompass all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.