Patent Description:
The present invention relates to tools and methods for locating subterranean objects and/or installing subterranean utilities (e.g., gas lines, water or sewer lines, etc.).

Prior to excavating a site containing soil over top of existing utilities, or an area with unknown utilities or other buried objects, it may be necessary to identify the location of any existing objects, such as utilities or other potential obstacles. In some cases, the objective may be to identify the location of the utilities so that they can be excavated. In other cases, the objective may be to identify the location of the utilities so that they can be avoided. Although some electronic locating tools and method are available, they may have relatively large tolerances (e.g., +/- <NUM> (<NUM> inches)) preventing precision excavation. "Soft digging" or "soft excavation" is required in such situations to avoid damaging any existing utilities. These "soft" operations can include manually excavating with one or more workers handling shovels or other tools. Other soft operations not relying solely on manual labor include vacuum excavation with a dig tube. These soft operations generally pose little risk for damaging existing utilities, but require opening of the ground and soil removal, thus creating potholes, to visually identify the existing utilities.

Once a site is at least partially excavated and existing underground objects have been identified, larger tools can be employed for further excavation and/or boring for utility line installation. In some cases, these tools are also used for installing the utility line. Existing tools include excavators, trenchers, horizontal directional drills (HDD), moles (pneumatic or hydraulic), and small drilling devices known as porta-bore. Any of these tools pose a risk to existing utilities if accidentally contacted due to malfunction or human error. Existing tools are either large and destructive, or small and difficult or impossible to steer.

In some HDD operations, it may be required to perform "potholing" during or after underground boring. Potholing involves the excavation of the ground to expose a utility for visual confirmation of its location and that the HDD boring did not come into contact or cause damage.

Whether created before or after the primary working operations, the potholes may become excessively large or numerous, especially if the object or utility is not in the expected location. Thus, a need exists for a soft excavation device and method that is effective yet capable of reduced soil disruption (e.g., smaller diameter holes, less spoils brought to the surface, etc.) and/or reduced labor in achieving the basic objectives currently met by potholing. <CIT> (D1) discloses a soft excavator is disclosed which utilizes a jet of high velocity fluid flow such as air or water flow, preferably supersonic, through a nozzle to excavate a material, such as the ground. A second passage for air flow is provided which is directed by an evacuator skirt in a direction along the excavator generally opposite the direction of discharge of the high velocity excavating flow to entrain the material excavated for disposal. <CIT> (D2) discloses a hand-held wand is disclosed for exposing buried objects such as utility lines or the like. The wand comprises an elongated, hollow tube having upper and lower ends with first and second water supply conduits being positioned adjacent the exterior surface of the tube. The lower end of the first water supply conduit has a digging nozzle mounted thereon. The lower end of the second water supply conduit extends upwardly into the lower end of the tube to create a vacuum or suction within the lower end of the hollow tube to remove muddy water from the hole being dug. A two-way valve is connected to the upper ends of the first and second water supply lines for alternately delivering water to the water supply conduits. The intake side of the two-way valve is in fluid communication with a source of high pressure water. The upper end of the hollow tube has a mud take-off hose connected thereto which may be utilized to convey the muddy water to a location remote from the hole being dug or to a container.

Features of the invention are set out in the independent claims. Preferred features of the invention are set out in the dependent claims.

<FIG> illustrate a water drilling system <NUM> according to one construction of the present disclosure. The water drilling system <NUM> includes a handheld water drill <NUM> or "wand" along with a high-pressure water source <NUM>. The high-pressure water source <NUM> can take numerous forms, including those of conventional construction. The high-pressure water source <NUM> can include a tank or reservoir and one or more pumps. The high-pressure water source <NUM> can be mobile (e.g., mounted on or built into a truck or trailer on wheels). In the system <NUM> illustrated in <FIG>, and <FIG>, the high-pressure water source <NUM> can be part of a hydro-vacuum excavation truck. The high-pressure water source <NUM>, particularly pumps thereof, may be powered by a prime mover separate from the vacuum excavator, or may be powered by the vacuum excavator (e.g., powered by the engine or electrical system of the vacuum excavator).

The handheld water drill <NUM> is connected to the high-pressure water source <NUM> with a hose <NUM>. As such, the hose <NUM> supplies water from the high-pressure water source <NUM> to the handheld water drill <NUM>, which may be referred to hereinafter as the wand <NUM>. As can be seen in <FIG>, the wand <NUM> includes an elongate hollow shaft <NUM> (also referred to as a "lance" or "wand body") configured to be plunged or thrust into ground soil. <FIG> illustrates the operator beginning a probing of the ground toward a pre-installed utility <NUM>, and <FIG> illustrates the operator having thrust approximately half of the wand length into the ground. As discussed in further detail below, the thrust for probing with the wand <NUM> is provided solely by the operator, i.e., manual thrust along the axis of the shaft <NUM>. In combination with the operator's manual thrust, water is ejected from a distal tip portion <NUM> of the wand <NUM> to cut away the soil. A spray shield <NUM> can be slidably received on the shaft <NUM> as shown in <FIG> to cover the aperture made in the ground as the wand <NUM> thrusts inward. The spray shield can be made of a suitable material such as rubber or plastic.

Axially or lengthwise-opposite the distal tip portion <NUM>, the wand <NUM> includes an operator's grip or handle portion <NUM>, shown in greater detail in <FIG>. Water ejection can be controlled (on/off or variably) by a control member such as a trigger <NUM> provided at the handle portion <NUM> (e.g., adjacent or within the handle portion). In some constructions, the trigger <NUM> can be surrounded by a guard portion of the handle portion <NUM>, either partially or fully encircled. The handle portion <NUM> can be of a cast or machined metal construction in some embodiments. The handle portion <NUM> of the wand <NUM> can include a main grip portion 124A configured to fit within the palm of the operator's hand. The trigger <NUM> can be moved into an actuated position toward or against the main grip portion 124A to be grasped and maintained actuated while holding the main grip portion 124A. The handle portion <NUM> can include a first connection structure <NUM> for mating with the hose <NUM>. The handle portion <NUM> can further include a second connection structure <NUM> for mating with the shaft <NUM>. The connection structures <NUM>, <NUM> are shown opposite each other on the illustrated handle portion <NUM>. In other constructions, where the second connection structure <NUM> to the shaft <NUM> forms a bottom portion, the first connection structure <NUM> can be positioned on a side, front, or rear of the handle portion <NUM>. The connection structures <NUM>, <NUM> provide mechanical and fluid connections, the fluid connections being sealed to prevent leakage of high-pressure water. In some constructions, one or both of the connection structures <NUM>, <NUM> are quick-couplers that require no tools and only simple hand operations to connect and disconnect. A top end <NUM> of the handle portion <NUM> can provide a pressing surface (e.g., flat surface) for the operator to apply thrust force during use.

In order to reduce the soil impact of using the wand <NUM>, the shaft <NUM> has a relatively small outside diameter D1. The shaft outside diameter D1 is no more than about <NUM> (<NUM> in). In some constructions, the shaft outside diameter D1 is no more than about <NUM> (<NUM> in). In some constructions, the shaft outside diameter D1 is in a range of <NUM> (<NUM> in) to <NUM> (<NUM> in). Although a thin shaft is preferable for minimal soil disturbance, the shaft <NUM> can have an outer diameter D1 of at least <NUM> (<NUM> in) in order to resist buckling under column loading conditions when thrust into the ground. As shown in <FIG>, the outside diameter D2 of the distal tip portion <NUM> is larger than the outside diameter D1 of the shaft <NUM>. For example, the outside diameter D2 of the distal tip portion <NUM> can be about <NUM> (<NUM> in) to <NUM> (<NUM> in). In some constructions, the outside diameter D2 of the distal tip portion <NUM> is <NUM> (<NUM> in) +/-<NUM> (<NUM> in). The ratio of D2:D1 is at least <NUM> and not more than <NUM>. In some constructions, the ratio of D2:D1 is in the range of <NUM> to <NUM>. In some constructions, the ratio of D2:D1 is in the range of <NUM> to <NUM> (e.g., <NUM>). The slightly enlarged distal tip portion <NUM> clears the path for the shaft <NUM>, reducing the amount of soil friction along the shaft <NUM>. The wand <NUM>, and particularly the respective outside diameters D1, D2 of the shaft <NUM> and distal tip portion <NUM>, is configured such that fluid, which may include water and/or slurry, in the bore hole (i.e., in the interstitial space between the shaft <NUM> and bore hole) may serve to lubricate the movement of wand <NUM> during penetration and withdrawal. As shown in <FIG>, the wand <NUM> has a length L that greatly exceeds the diameters D1, D2 (e.g., L:D2 at least <NUM>, at least <NUM>, or at least <NUM>). The wand length L, or effective probe length, can include the ground-penetrating portions only, i.e., the shaft <NUM> and the distal tip portion <NUM>, but not the handle portion <NUM>. The above dimensions and ratios that relate to the shaft <NUM> can be applicable for a majority or in some cases an entirety of the length L, rather than merely a localized portion.

The shaft <NUM> can be constructed from any one or more of numerous suitable materials, including non-metallic materials. In some constructions, the shaft <NUM> is made of carbon fiber, fiberglass, polyimide, nylon, PEI (e.g., Ultem®), PTFE, PEEK, PPSU, PES, PEED, PVDF, PET-P (Ertalyte®), silicon nitride, fused quartz, or epoxy-fiberglass (e.g., G10 or garolite). Certain materials, including but not limited to nylon, PEEK, and PPSU, may be reinforced with a filler material such as glass or carbon fiber. In some embodiments the filler is present in a quantity of <NUM> - <NUM>% by weight (e.g., <NUM>% by weight). A lighter weight of the shaft <NUM> allows better operator feel during use, when compared to a heavy shaft, so the user can more easily detect contact with objects (i.e., changes are more discernable as the user applies downward force). The shaft <NUM> may be constructed of an electrically non-conductive material, or a material having high electrical resistivity. The resistivity of the wand <NUM> is greater than the resistivity of the water directed through the wand <NUM>. In particular, the resistivity of the shaft <NUM> is greater than the resistivity of the water directed through the wand <NUM>. In some constructions, the resistivity of the shaft <NUM> (e.g., and that of the wand <NUM> overall) is at least <NUM>Ωm, or at least <NUM>,<NUM>Ωm. In some constructions, the resistivity of the shaft <NUM> (e.g., and that of the wand <NUM> overall) is orders of magnitude higher, such as 1x10<NUM> Ωm to 1x10<NUM> Ωm. The material for the distal tip portion <NUM> can be different from that of the shaft <NUM>. In some constructions, the material for the distal tip portion <NUM> is a harder, more wear-resistant material than that of the shaft <NUM>. Some exemplary materials for the distal tip portion <NUM> include zirconia, ceramic, and tungsten carbide.

The distal tip portion <NUM> forms a blunt end rather than a sharp tip. Rather than mechanically cutting or wedging into the soil by a sharp tip or edge, the wand <NUM> relies on the jet(s) of water for cutting away the soil to allow the insertion of the shaft <NUM>. The water jet(s) are effective at cutting into the soil to form a small hole suitable for probing, without being overly destructive. In other words, the wand <NUM> prevents the need to excavate and physically remove soil away from the location of interest. There is no open pit and no additional pile of spoils when using the wand <NUM>. Furthermore, the water jet(s), while effective for cutting the soil, are harmless to the utilities for which the wand <NUM> is probing. This is unlike conventional powered tools that are likely to include sharp points or bits. Moreover, the wand <NUM> is not a spinning tool and need not be put into rotation in order to pierce the ground. It can be solely thrust into the ground, without rotation. The water pressure to the wand <NUM> should be at least <NUM> bar (<NUM> psi). In most constructions, the water pressure does not exceed <NUM> bar (<NUM> psi). In some constructions, the water pressure is in a range of <NUM> bar (<NUM> psi) to <NUM> bar (<NUM> psi). More particularly, the water pressure may be in a range of <NUM> bar (<NUM> psi) to <NUM> bar (<NUM> psi). Operational methods can include adjusting the water pressure based on soil conditions, the adjustments being made as an initial setting prior to use of the wand <NUM> and/or after observing initial operation of the wand <NUM>. Water pressure may be adjusted upwardly if the wand <NUM> cuts too slowly into the ground, and water pressure may be adjusted downwardly if the use of the wand <NUM> results in excessive spray of water and/or spoils out of the ground.

With reference to <FIG> and <FIG>, the distal tip portion <NUM> can include a nozzle <NUM> including a plurality of nozzle apertures. The distal tip portion <NUM> is formed solely by the nozzle <NUM>. As illustrated, each of the nozzle apertures has an at least partially (e.g., predominantly) axial orientation. The nozzle apertures can include inner nozzle apertures <NUM> and outer nozzle apertures <NUM>. The inner and outer nozzle apertures <NUM>, <NUM> can have angular orientations that are different from each other. The apertures may create a spiral spray pattern. For example, the outer nozzle apertures <NUM> can have a greater divergence angle with respect to a central axis A. The divergence angle of the outer nozzle apertures <NUM> can be in a range of <NUM> to <NUM> degrees, or more particularly <NUM> to <NUM> degrees. The divergence angle of the inner nozzle apertures <NUM> can be less than half the divergence angle of the outer nozzle apertures <NUM>. In some constructions, the inner nozzle apertures <NUM> have a divergence of less than <NUM> degrees from the central axis A. In some constructions, the apertures may have a straight spray pattern where the inner nozzle apertures <NUM> have a divergence angle of zero degrees, therefore being parallel to the central axis A. As shown in <FIG>, the nozzle <NUM> can include a counterbore receptacle <NUM> configured to receive the end of the shaft <NUM>. The nozzle <NUM> can be fixedly connected to the shaft <NUM> by an end connector (not shown) affixed to or integrated into the shaft <NUM> or by other suitable means (e.g., bonded, threaded, secured by quick-connect structures) to contain and direct the pressurized water and to withstand the external loads encountered during use. The nozzle <NUM> can be one of a plurality of removable, exchangeable nozzles to be used in different operations and/or different soil conditions.

<FIG> illustrate an alternate nozzle <NUM> that can be used with a wand and system as described elsewhere herein. The nozzle <NUM> includes a plurality of nozzle apertures <NUM>. The distal tip portion <NUM> is formed solely by the nozzle <NUM>. As illustrated, each of the nozzle apertures <NUM> has a straight axial orientation, parallel to the central axis A. The nozzle apertures <NUM> can include a central nozzle aperture <NUM> and a plurality of additional or peripheral nozzle apertures <NUM> (e.g., spaced equally from the central nozzle aperture <NUM>). There are five nozzle apertures <NUM> in the illustrated embodiment, but the number of nozzle apertures may be greater or fewer than five in other embodiments. In some embodiments, some or all of the nozzle apertures <NUM> may have a divergence angle (e.g., similar to the nozzle <NUM> of <FIG>). As shown in <FIG>, the nozzle <NUM> can include a connection structure <NUM> (e.g., threaded portion) configured to engage with the end of the shaft <NUM>. In the illustrated construction, the connection structure <NUM> is a male threaded portion. The nozzle <NUM> can include features <NUM> such as wrench flats on an exterior profile thereof so that the nozzle <NUM> can easily be gripped for torque application for assembly and/or disassembly. In the illustrated construction, the nozzle <NUM> has a round or circular profile with the exception of the wrench flats <NUM>.

The nozzle <NUM> and the shaft <NUM> can be fixedly secured together (e.g., bonded, threaded, secured by quick-connect structures) by suitable means to contain and direct the pressurized water and to withstand the external loads encountered during use. Details of exemplary means of securement are described in further detail below, particularly with reference to <FIG>. The nozzle <NUM> can be one of a plurality of removable, exchangeable nozzles to be used in different operations and/or different soil conditions. In some constructions, a nozzle similar to the nozzles illustrated and described herein may be provided with a singular aperture for discharging the water.

As noted above, the wand <NUM> can be connected to a hydro-vacuum excavation truck. This is one example of a road-going vehicle capable of legal travel about public roadways or highways. <FIG> illustrates a water drilling system <NUM> according to another construction of the present disclosure is a smaller and more maneuverable version of the system <NUM> - one that can be better suited for off-road and/or remote access locations. The water drilling system <NUM> includes the wand <NUM> along with a high-pressure water source <NUM> that is temporarily or permanently mounted onto a personal transport device (e.g., a small off-road vehicle configured for carrying <NUM> or <NUM> people). In some constructions, the system <NUM> includes a commercially available all-terrain vehicle (ATV). The high-pressure water source <NUM> can be an active water source configured to selectively operate to generate high-pressure water (e.g., pump(s) driven from a prime mover such as an electric motor or gas-powered engine - either standalone or that which provides power to drive the vehicle). <FIG> illustrates the high-pressure water source <NUM> including a water tank <NUM> (for unpressurized water) and a self-contained pumping device <NUM> having a fluid connection to receive water from the water tank <NUM>.

A non-destructive probing operation with the water drilling system <NUM> shown in <FIG>, and <FIG>, or the water drilling system <NUM> shown in <FIG>, includes the following steps. The wand <NUM> is transported, along with the pressurized water source <NUM> or <NUM>, to a work site. The work site may be pre-marked for underground utilities in some constructions. The worker connects the wand <NUM> to the pressurized water source <NUM> or <NUM>, if not already connected. Likewise, the pressurized water source <NUM> or <NUM> is operated to pressurize the water, if not already pressurized. It will be appreciated that the systems <NUM>, <NUM> can be transported in ready-to-use state, or alternately made ready at the site of the probing. When the system <NUM>, <NUM> is ready or "charged," operation of the trigger <NUM> will produce water jets from the distal tip portion <NUM>. The operator selects a ground location for probing, which may be selected on or near a marking established from other means. The objective of probing can be to identify the precise location of a buried object, or to confirm the absence of buried objects at a specific location. A non-exhaustive list of possible buried objects includes: utility lines (e.g., natural gas, water, communications, etc.), drainage tiles such as agricultural drainage tile, natural obstacles such as rocks encountered during other drilling or excavation processes, manmade obstacles such as the foundation of an above-ground construction (e.g., building, power pole, etc.). Water drilling or "probing" with the wand <NUM> can be used to understand how large a buried object is (by identifying its outer limits through probing contact) so that the trencher or HDD can steer around it. The probing can also be used when potholing during/after HDD bore formation, for example to allow very precise potholes to be excavated for visual confirmation of avoidance of contact or damage.

The operator places the distal tip portion <NUM> on the ground at the selected location and holds the wand <NUM> such that the shaft <NUM> is vertical (perpendicular to the ground). However, it is noted that some probing operations may call for probing at skewed angles rather than strictly vertical (e.g., to avoid a shallower utility or obstacle such as a tree root). With the wand <NUM> in the desired probing orientation, the operator actuates the trigger <NUM>. While maintaining the trigger <NUM> actuated, the operator manually applies thrust load to the wand <NUM>. With the trigger <NUM> actuated and thrust load applied, the wand <NUM> cuts into the soil and creates a localized path or bore that is nominally larger than the outer diameter D2 of the distal tip portion <NUM>. In some constructions, the wand <NUM> forms a bore that is about <NUM> (<NUM> in) to about <NUM> (<NUM> in) larger than the outside diameter D2 of the distal tip portion120. This allows for a reasonable thrust load (e.g., <NUM> (<NUM> lbs. ) or less, or <NUM> (<NUM> lbs. ) or less) to probe the wand <NUM> into the ground - up to and including the entire length L. Probing the wand <NUM> its full length into the ground can be accomplished, depending on soil type, in less than <NUM> seconds, and in some cases less than <NUM> seconds or less than <NUM> seconds. The soil from which the bore is formed is largely not removed from the ground. Rather, it is simply broken up along the path of the probing, and generally compacted in the immediate surroundings. The operator pulls the wand <NUM> backward out of the ground following a probe. Minimal spoils, including soil and water, may be ejected from the ground to the surface during probing. In some cases, depending upon soil conditions, spoils cease to surface above ground after an initial insertion depth of the wand <NUM> (e.g., after <NUM> (<NUM> in. ), after <NUM> (<NUM> in. ), or after <NUM> (<NUM> in. If the probing is aimed such that it comes into contact with the utility <NUM>, the probing is obstructed, and the operator can feel the contact to detect the utility <NUM>. The water does not damage the utility <NUM>. Of course, the utility <NUM> is merely one example of an underground object that the operator may be probing for in the soil.

The views of <FIG> and <FIG> illustrate several prior probe tracks T or "misses," including tracks left and right of the final probe track in which the distal tip <NUM> of the wand <NUM> makes contact with the utility <NUM>. <FIG> in particular shows a method in which multiple probe tracks T are formed at different angles (which may optionally include one that is straight vertical), all of which utilize a single entry point in the ground. Once the utility <NUM> is contacted, its precise location underground can be used for improved marking and/or immediate precision excavation. Not only is the plan view location of the utility <NUM> determined from probing, but also its depth by taking note of the exposed length of the wand <NUM> at the time of contact. The wand <NUM> can have an integrated depth scale (e.g., printed or engraved length markings), an example of which is shown in <FIG>. Due to its minimal impact to the ground during operation, there may be no required backfill and no required removal of spoils following use of the wand <NUM> (e.g., ground disruption of an amount less than that which may trigger local regulations for remedial action). In other words, the probing with the wand <NUM> does not necessitate any remedial processing following use, and the ground can be left as-is following use. This can have a very significant impact on the required time (and also cost) for this phase of the job. Not only does the wand <NUM> allow quicker actual determination of the object compared to conventional methods, but the conventional methods also require management and often removal of the spoils.

<FIG> illustrates another operation of the wand <NUM> of the system <NUM> or <NUM>, which is one of boring rather than probing. The boring operation may involve a generally horizontal orientation of the longitudinal axis of the wand <NUM>. As illustrated, an obstruction <NUM> may exist at the ground surface. For example, the obstruction <NUM> can be a driveway, sidewalk or other concrete or asphalt structure, among other things. Also, the obstruction may be another preexisting underground utility. To avoid excavating (and keep the obstruction <NUM> in-tact), pits are dug on two opposite sides of the obstruction <NUM>. The pits are dug to a depth at least as great as a desired depth of the horizontal bore desired below the obstruction <NUM>. One pit (right) is the entrance pit <NUM>, and the other pit (left) is the exit pit <NUM>. Horizontal spacing between the pits <NUM>, <NUM> can be relatively small (e.g., less than <NUM> feet, less than <NUM> feet, or less than <NUM> feet) and may be kept less than the length L. In other constructions, larger spacings can be accommodated by adding effective wand length by fitting additional shaft segments, as described in further detail below. The wand <NUM> is positioned in the entrance pit <NUM> and the distal tip portion <NUM> is placed in contact with the generally vertical soil wall adjacent to the obstruction <NUM>. The operator holds the wand <NUM> such that the shaft <NUM> is horizontal (parallel to the ground). However, it is noted that some boring operations may call for probing at skewed angles rather than strictly horizontal. With the wand <NUM> in the desired boring orientation, the operator actuates the trigger <NUM>. While maintaining the trigger <NUM> actuated, the operator manually applies thrust load to the wand <NUM>. The wand <NUM> is thrust generally horizontally and thus perpendicular to the vertical soil wall in the entrance pit <NUM>. With the trigger <NUM> actuated and thrust load applied, the wand <NUM> cuts into the soil and creates a localized path or bore approximately the diameter D2 of the distal tip portion <NUM>. This allows for a reasonable thrust load (e.g., <NUM> (<NUM> lbs. ) or less, or <NUM> (<NUM> lbs. ) or less) to bore through the ground into the exit pit <NUM> - up to and including the entire length L. The soil from which the bore is formed is largely not removed from the ground. Rather, it is simply broken up along the path of the probing, and generally compacted in the immediate surroundings. Any spoils that are produced simply fall into the entrance or exit pit <NUM>, <NUM>. Thus, the wand <NUM> and its use in boring as described above meet the need for a less invasive and destructive means of boring, creating only a small diameter bore and requiring substantially reduced labor effort than existing tools and methods.

When the bore hole between the pits <NUM>, <NUM> is completed, a product to be installed can be attached to the end of the wand <NUM> and pulled through the bore hole as shown in <FIG> and <FIG>. An example product <NUM> is shown in <FIG> and <FIG>, coiled on a reel <NUM> to unwind during pullback by the wand <NUM>, for example by connection of a coupler <NUM> therebetween. The nozzle <NUM> can be removed for product attachment or left in place. If the nozzle <NUM> is removed, it may be replaced with a product attachment device. Alternative to the method shown in <FIG> and <FIG>, the wand <NUM> can be pulled backward out of the newly-formed borehole directly after boring, and then the product is subsequently pushed through the bore hole. The bore hole can optionally be enlarged by additional passes (reaming the hole) or by using other nozzles (e.g., with the wand <NUM>) that are configured for hole widening. A bore hole enlargement tip can include at least one product attachment feature so that bore hole widening and product installation can be completed concurrently. The coupler <NUM> for product attachment can include various slings and riggings (commercially available or fabricated on-site), or barbed push-on couplers, or any other coupler known in the art. Product to be installed can be fiber optic cable, other power and/or communication wires, or simply a conduit. As can be appreciated, an open trench is not required. This process can be followed, whether or not there exists an obstruction <NUM> that physically prevents trenching, e.g., anywhere minimal/no disturbance to the surface is desired (short shots to homes or buildings). The boring operation with the wand <NUM>, excluding the formation of the pits <NUM>, <NUM>, avoids the removal of soil so as to be non-destructive to the original ground, including the obstruction <NUM>.

The use of the wand <NUM> has been demonstrated to produce several unexpected results during probing and/or boring, and these include:.

An alternative wand <NUM> is shown in <FIG>, the wand <NUM> sharing the features and uses of the wand <NUM> described above except as noted below. Features introduced in <FIG> can be used throughout the preceding embodiments, either together or in isolation as desired. The wand <NUM> has an additional handle portion <NUM> so that a T-shaped handle is formed for grasping and operating the wand <NUM>. The two handle portions <NUM>, <NUM> extend perpendicular to and across the shaft <NUM>. The handle portion <NUM> can be a simple rod, bar, or shaft, devoid of triggering controls for the water. The handle portion <NUM> can be similar to the handle portion <NUM> and configured to control the water, at least providing ON/OFF control of the water discharge. At the distal tip portion <NUM>, the wand <NUM> is configured for connection with one or more nozzles that may vary in aperture configurations to provide different spray patterns. <FIG> illustrates the nozzle <NUM> of <FIG>. The different nozzles can be selected for attachment with the wand <NUM> based on the job and/or conditions at hand: <NUM>) boring versus probing may utilize different nozzles, <NUM>) pilot holes verses hole enlargement/reaming may utilize different nozzles, <NUM>) different earth/soil conditions may require different nozzles for efficient penetration and cutting (clay, sand, loam, and combinations thereof).

The shaft <NUM> is part of a multi-piece shaft assembly (also referred to as the "lance" or "wand body") that includes the shaft <NUM> and fittings <NUM> fixed at both opposite axial ends of the shaft <NUM>. The shaft <NUM> can have a construction that is generally similar to the shaft <NUM> shown and described above, including exemplary materials and sizing, etc. As such, those details are not repeated here. The fittings <NUM> can be permanently affixed to the shaft <NUM> at one or both ends. This means that, as opposed to being constructed with connection means configured for repeated assembly and disassembly (e.g., threaded joints, quick-connects), the fittings <NUM> are secured to the shaft <NUM> by means that A) are intended to remain in-tact for the life of the wand <NUM> and/or B) require breakage to disconnect. In some constructions, the fittings <NUM> are bonded to the shaft <NUM>. The fittings <NUM> can be bonded to the shaft <NUM> with epoxy (e.g., <NUM>-part epoxy). Each fitting <NUM> can have a connection structure at the outward end thereof such as a threaded portion <NUM> (e.g., female pipe thread) or a quick-connector so as to facilitate repeated assembly and disassembly with adjacent structures. The threaded portion <NUM> or other connection structure is complementary with a connection structure provided on the adjacent component (e.g., the handle <NUM> on the proximal end and the nozzle <NUM> on the distal end). Each fitting <NUM> can include features <NUM> such as wrench flats on an exterior profile thereof so that the fitting <NUM> can easily be gripped for torque application for assembly and/or disassembly. In the illustrated construction, each fitting <NUM> has a round or circular profile with the exception of the wrench flats <NUM>.

In some constructions, the multi-piece shaft assembly formed by the shaft <NUM> and the fittings <NUM> is bi-directional such that it can be connected between the handle portion <NUM> and the nozzle <NUM> in a first orientation and a second reversed orientation. In other words, either of the two fittings <NUM> can be connected to the handle portion <NUM> and the other fitting can be connected to the nozzle <NUM>. However, it is also contemplated that the fittings <NUM> can be different from each other in construction and/or attachment to the shaft <NUM> at the two different ends. In some constructions, the shaft <NUM> may include only one permanently affixed fitting <NUM>. In some constructions, one or both of the fittings <NUM> (and in some cases also the nozzle <NUM>) is constructed of metal. Removable and exchangeable nozzles (e.g., by threaded connection or quick-connect) can be implemented in the wand <NUM> of the preceding embodiment as well.

<FIG> illustrates the multi-piece shaft assembly formed by the shaft <NUM> and the fittings <NUM> used with the handle portion <NUM> of the preceding wand embodiment. In exploded assembly view, the multi-piece shaft assembly is shown with a direct threaded connection to the nozzle <NUM> at the bottom of the view. At the top of the view, an indirect connection is made between the handle connection structure <NUM> and the fitting <NUM>. A thread adapter <NUM> is secured to the fitting <NUM> and acts as a pipe nipple increaser. Quick-connect adapters <NUM>, <NUM> are threaded to the thread adapter <NUM> and the handle connection structure <NUM>, respectively. The overall wand assembly of <FIG> is also illustrated with an alternate spray shield <NUM>' having an elongated taper section for engaging the multi-piece shaft assembly.

<FIG> illustrate a cross-section of the shaft <NUM> and one of the fittings <NUM> permanently affixed (e.g., bonded) thereto. As shown there, the fitting <NUM> has a first portion provided with the threaded portion <NUM>. The threaded portion <NUM> is open to the environment at one end and open to a shaft-receiving portion at the other end. At the shaft-receiving portion, the fitting <NUM> provides an inner cylindrical surface configured to receive and form an interface <NUM> with the outer cylindrical surface of the shaft <NUM>. The shaft <NUM> and the fitting <NUM> are bonded (e.g., with epoxy) along all or a portion of their interfacing cylindrical surfaces. The bonded interface <NUM> can extend along a greater axial length than the threaded portion <NUM>. Although the shaft <NUM> can be inserted fully into the fitting <NUM> (up to an internal shoulder <NUM> formed between the threaded portion <NUM> and the shaft-receiving portion), water at high pressure may get between the shaft <NUM> and the fitting <NUM>. Adjacent the shoulder <NUM> and the end of the shaft <NUM>, a seal structure is provided to seal the bonded interface from the interior of the shaft <NUM>. The seal structure in the illustrated embodiment includes an O-ring <NUM> and a back-up ring <NUM>. The O-ring <NUM> acts a seal between the shaft <NUM> and the fitting <NUM>, and the back-up ring <NUM> provides mechanical support and protection to the O-ring <NUM>.

<FIG> illustrates an optional configuration in which the shaft <NUM> is provided with ribbing <NUM> in the form of radial projections or barbs. The ribbing <NUM> can be formed by manufacturing the shaft <NUM> with an enlarged end section and then selectively removing material (e.g., by machining). The ribbing <NUM> is exaggerated in <FIG> for clarity. The ribbing can include more or fewer structures than the three shown. In lieu of or in addition to bonding, the interface <NUM> between the shaft <NUM> and the fitting <NUM> can be mechanically secured by applying clamping load with a clamp <NUM> around the fitting <NUM> at the axial location of the ribbing <NUM>. In some constructions, the ribbing <NUM> can be provided internally on the fitting <NUM> to face toward the outside of the shaft <NUM>. The clamp <NUM> can take any suitable form, including a hose clamp, spring clamp, band clamp, pipe clamp, etc. As illustrated by the lack of cross-hatching, a portion of the fitting <NUM> can be slit axially to facilitate inward clamping deflection. When clamped, the ribbing <NUM> at the interface <NUM> bites into the adjacent material to increase the mechanical strength of the joint. This type of interface <NUM>, which may lack any separate bonding material between the shaft <NUM> and the fitting <NUM>, can be self-sealing and having no separate seal. Alternatively, a separate seal may be provided (e.g., the O-ring <NUM> and back-up ring <NUM>).

Although the bonded and/or clamped interface <NUM> has proven successful, there remain additional optional constructions for making end connections on the shaft <NUM>, and some of these are listed below. Those of skill in the art will realize that each connection method can be carried out in a variety of ways, and may be material dependent in some aspects. In one construction, the fitting <NUM> is threaded to the shaft <NUM>. In other constructions, the fitting <NUM> is shrink-fit or crimped to the shaft <NUM> (e.g., similar to the construction of hydraulic hoses/fittings). In yet another construction, the fitting <NUM> can be cast, melted, or welded into or onto the shaft <NUM>. In some cases, the shaft <NUM> and the fitting <NUM> are manufactured from the same material and bonded with hot melt adhesive. In yet other constructions, the fitting <NUM> is embedded (e.g., by pultrusion) or shrink fit to the shaft <NUM>. In another construction, the fitting <NUM> has an integrated shaft collar style clamp that is operable to squeeze onto the shaft <NUM>. Some or all of the above may be used for connecting the shaft <NUM> with the nozzle <NUM> or other structure, without the fitting <NUM> as an intermediary. In yet another construction, the distal tip <NUM> is provided without a separate nozzle, and the nozzle aperture(s) are formed directly in the material of the shaft <NUM>. As such, the shaft <NUM> can be manufactured with a solid end and then machined (e.g., drilled) to provide the nozzle apertures. Alternately, the end of the shaft <NUM> can be provided (e.g., cast, molded) with the nozzle apertures at the time of original manufacture. Silicon nitride material may be used to facilitate certain manufacturing processes noted above, as it may be machined and/or welded in some cases.

<FIG> illustrates a wand <NUM> built with a handle portion <NUM> and a plurality of separable shafts or shaft sections to form the lance or wand body as a shaft string <NUM>. In other words, the total length of the lance or wand body is the combined length of the connected shafts. As illustrated, the wand <NUM> includes a plurality of the of the multi-piece shaft assemblies of <FIG>, each including a shaft <NUM> and two end fittings <NUM>. The shaft string <NUM> can be constructed from shafts of other constructions, including various embodiments disclosed elsewhere herein. Referring specifically to <FIG>, a first shaft assembly is coupled to the handle portion <NUM> and a second shaft assembly is coupled to the nozzle <NUM>. The first and second shaft assemblies are coupled to each other with at least one coupler fitting <NUM>, for example a double pipe nipple. One threaded portion of the coupler fitting <NUM> is engaged with the distal fitting <NUM> of the first shaft assembly, and the other threaded portion of the coupler fitting <NUM> is engaged with the proximal fitting <NUM> of the second shaft assembly. The coupler fitting <NUM> can have an outer diameter that is equal to or less than the outer diameter at the distal tip (e.g., the nozzle diameter). In some constructions, the outer diameter of the coupler fitting <NUM> is equal to or less than the nominal outer shaft diameter D1 so as to avoid any bulging or increase in the outer diameter when traversing the length of the shaft. This type of shaft string <NUM> can be used in any of the wands and any of the methods described in the present disclosure. Rather than a singular, contiguous shaft as shown in the preceding embodiments, the shaft string <NUM> is made up of multiple (e.g., at least two, but optionally three, four or more) shaft segments connectable together for use in connecting a handle portion to a nozzle at the distal tip. As noted above, each fitting <NUM> provides a connection structure via the threaded portion <NUM>. In other constructions, the shaft sections can be provided with alternate connection structures (threaded or otherwise) to enable connection of the multiple shaft sections in forming the wand body. In this way, the length of the wand to be used by the operator can be selected by the operator and can optionally be increased or decreased during a particular job. Storage and transport of the wand can be made easier by allowing the disassembly of the shaft sections.

<FIG> illustrate alternate wand bodies that are constructed with shafts <NUM>, <NUM> that are forked at the distal end so as to provide multiple (e.g., two) "tines" extending to multiple distal tips <NUM>, <NUM>, each distal tip having a nozzle (e.g., nozzle <NUM>). The forked portions can have various shapes (including straight and/or angled sections), two of which are depicted in <FIG>. In <FIG>, each tine of the fork has a proximal portion angled <NUM> degrees outward from the longitudinal axis, the proximal portion extending to a distal portion through an additional bend back <NUM> degrees so the distal portion is parallel to the longitudinal axis. In <FIG>, the proximal portion of each tine of the fork is angled <NUM> degrees outward from the longitudinal axis. There may be multiple upstream water discharge holes <NUM>, <NUM> along the top and/or sides, along with the nozzle apertures at the tips <NUM>, <NUM> of the forks. The fork may be configured in various withs, from a narrow spacing between the tines (e.g., <NUM> (¾ inch), <NUM> (<NUM> inch), or <NUM> (<NUM> inches)), to a wide spacing between the tines (e.g., up to <NUM> (<NUM> inches)). The tine length can vary from just the length of a nozzle to longer lengths (e.g., <NUM> (<NUM> inches) to <NUM> (<NUM> inches)). Longer tines may provide additional space for a plurality of additional water discharge holes along the inside, prior to the nozzle at the distal tip. The forked probe may be used for initial utility locating or cleaning and probing within an existing hole/excavation. In some cases, a wand having the shaft <NUM>, <NUM> forms at its distal end a yoke that may be used to catch a utility therein after piercing into the soil. The shafts <NUM>, <NUM> may be composed of materials similar to the other shafts described herein. Other than the particular variations noted herein, the shafts, nozzles, etc. of <FIG> can conform to the preceding disclosure.

Claim 1:
A water drilling system (<NUM>, <NUM>) comprising:
a handheld wand (<NUM>) having a handle portion (<NUM>, <NUM>, <NUM>) and a distal tip (<NUM>);
a pressurized water source; and
a hose connecting the handheld wand (<NUM>) and the pressurized water source,
wherein the handheld wand (<NUM>) is controllable to selectively discharge pressurized water from a nozzle (<NUM>) at the distal tip (<NUM>),
wherein a non-metallic hollow shaft (<NUM>) of the handheld wand (<NUM>) is configured to be thrust into ground soil, the hollow shaft (<NUM>) extending between the handle portion (<NUM>, <NUM>, <NUM>) and the distal tip (<NUM>), the hollow shaft (<NUM>) having an outside diameter less than an outside diameter of the distal tip (<NUM>),
wherein the outside diameter of the hollow shaft (<NUM>) is no more than about <NUM> (<NUM> in),
wherein the distal tip (<NUM>) is formed solely by the nozzle (<NUM>), and
wherein the ratio of the outside diameter of the distal tip (<NUM>) to the outside diameter of the shaft (<NUM>) is between at least <NUM> and no more than <NUM>.