Abstract:
A flute-wiping auger cleaner has a laterally-shearing shackle, an axial track spaced parallel to the auger; and a traveling carriage on the track for supporting the shackle. The shackle includes a series of angularly-staged wiper blades to project into the flute of the auger and centrally stabilize the blades on the turning axis of the auger. The shackle is biased not only to pressure the wipers inwards towards the auger&#39;s cylindrical sidewall but also allow the shackle to open slightly against the force of the bias in event a blade cannot dislodge a difficult clump of fouling material in the flute. In that event, the blade is pushed out and then pressured back in as it rides over the difficult-to-dislodge clump. Spinning the auger causes the blades to travel the length of the helical flute while the shackle travels axially on the track.

Description:
CROSS-REFERENCE TO PROVISIONAL APPLICATION(S) 
   This application claims the benefit of U.S. Provisional Application No. 60/853,970, filed Oct. 23, 2006, which is incorporated herein by this reference thereto. 

   BACKGROUND AND SUMMARY OF THE INVENTION 
   The invention relates to boring the earth and, more particularly, to an above-ground cleaner for the earth bore that will strip, wipe, scrape, or break off adhering accumulations of mud or cuttings. 
   The inspiration for the invention includes without limitation the activity of hollow stem auger retraction from being downhole, as in a well bore. The conventional occasion nowadays for wanting to do so is during construction of an environmental monitoring well. 
   Briefly, groundwater monitoring/remediation wells are bored into the earth. A bore hole is formed by down-feeding a string of hollow stem auger sections.  FIG. 1 , for example, shows the topmost section of such an auger string (the rest of the string being downhole and out of view). Once the string has bored through to the desired depth, the process then begins of retracting the string. 
   The purpose behind the auger sections (and consequent string) being hollow is for the down-feeding and construction of a well-casing in the lumen (hollow core) of the auger string. A casing is typically an assembly of PVC pipe sections twisted together by the counterpart internal and external threaded ends thereof. The casing is intentionally undersized relative to the lumen of the hollow stem auger string in which it is inserted. That way, the hollow stem auger string can be withdrawn from the bore, leaving the PVC pipe casing in place. Also, such an undersized casing presents an annular gap between the bored earth and PVC pipe, and this annular gap is eventually backfilled. 
   To turn to another matter of the prior art, there is another piece of the background to note, which involves the field equipment used by the workers in this industry:—namely, their drilling rigs. Such drilling rigs have two kinds of devices for retracting the hollow stem auger string:—(1) hydraulically-winched cables or lines, in contrast to, (2) hydraulic cylinders. 
   It might be noted that hydraulically-winched cables and lines, when used to pull free a stuck object, typically include the danger of recoil. Conversely, hydraulic cylinders in the same situation are essentially recoilless. Another thing about hydraulic-cylinder systems is that, they are powerful, and typically outmuscle the power of the hydraulic winches by several times. 
   A typical drilling rig utilized in the industry might comprise, for example and without limitation, a CME 750 All-terrain vehicle (a rubber tire vehicle) drilling rig of the Central Mine Equipment Company in St. Louis, Mo. This is the carrier/drilling rig combination which is approximately illustrated in several patents of the CME Company, and for more particular disclosure of such carrier/drilling rig features, reference may be had to any of U.S. Pat. Nos. 3,527,309; 3,561,545 and/or 4,638,871—all of which are by C. L. Rassieur. The foregoing patent disclosures are incorporated fully herein by this reference thereto. 
   Such a carrier/drilling rig has a two-piece tower comprising, in its lower portion, an undergirding upright, and affixed upon that, a removable mast. The crown of the mast might be outfitted with as many as five sheaves. In a five sheave configuration, typically one sheave serves a wireline cable and winch, another serves softlines perhaps pulled by a cathead, and the remaining three would typically serve three cable-and-winch systems for winching up (for example) sections of drill rod. 
   The wireline cable and softline-cathead system are not pertinent to the present invention. Typically the wireline cable system reels up a wire relatively fast but with a weak hoist. A weak hoist, for instance, is only able to exert 900 pounds or  ˜ 400 kg of force or so, which is fine for rock-coring but is otherwise weak. The cathead is like a capstan on a ship, except oriented on a horizontal turning axis, and can winch in by means of one or two loops not only softlines but also cables or chains as well. It too is typically a weak system. 
   Stronger still are the (three or so) cable-and-winch systems. It is typical to equip the drilling rig with winches rated between about 1,800 or to 3,200 pounds ( ˜ 700 to  ˜ 1,400 kg). It is also known to include at least one cable-and-winch system as a main one for fishing stuck objects and the like, and provide it with a retraction-force rating as high 10,000 pounds ( ˜ 4,500 kg). Again, these three cable-and-winch systems are designed for, among other end uses, lifting up sections of drill rod. The height of the tower to the crown of the mast is typically something greater than twenty feet ( ˜ 6 m) since that is a standard length of sections of drill rod. The above-ground height of the sheaves for the CME 750 ATV is about twenty-seven and a-half feet ( ˜ 8⅓ m), which means that workers can hoist the twenty-foot ( ˜ 6 m) rods with clearance to spare. When the CME 750 ATV is equipped with three such hoists (ie., cable-and-winch systems), workers can pull sixty feet of rods without having to lay any down on the ground or on the deck. 
   The upright (again, the lower part of the tower, which undergirds the upper part, the detachable mast) comprises legs and a standing rotary drive shaft (such as a kelly bar, or sometimes a square bar). The standing rotary drive bar typically has a lower end anchored in a main rotary drive and an upper end held in a bearing. The legs carry between (or among) themselves a traveling rotary table. Drive input to the rotary drive table is received from the standing rotary drive shaft as the traveling rotary table transits up and down the standing rotary drive shaft. The drill drive is typically a pair of serially-suspended links interconnected by a U-joint. 
   The hydraulic vertical drive system for cycling the traveling rotary drive table between feed (“pulldown”) and retraction strokes typically comprises hydraulic cylinders. Theses hydraulic cylinders serve double-duty as the legs for the tower&#39;s upright. The main rotary drive and the hydraulic vertical drive system are typically the strongest systems on the carrier/drilling rig. That is, the main rotary drive might deliver 10,000 ft-lbs ( ˜ 13,5000 Nm) of rotary torque. The hydraulic vertical drive system can typically deliver a feed (“pulldown”) force in excess of the weight of the vehicle, or something on the order of 20,000 pounds ( ˜ 9,000 kg). 
   The outstanding feature of the hydraulic vertical drive system is the retraction force it can develop:—which is 30,000 pounds ( ˜ 13,600 kg) for the CME 750 ATV, and then 40,000 pounds ( ˜ 18,000 kg) being no problem for other models. 
   As an aside, another aspect of the hydraulic vertical drive system is that, its drive stroke is only about five and a-half feet ( ˜ 1⅔ m). Unlike drill rod sections (which measure a standard twenty feet or six meters in length), hollow stem auger section conventionally measure a standard five feet ( ˜ 1½ m) in length. Therefore, the hydraulic vertical drive system&#39;s drive stroke of about five and a-half feet ( ˜ 1⅔ m) is more than sufficient to provide clearance for withdrawal of hollow stem auger sections. 
   More importantly, the hydraulic vertical drive system has no cables which can stretch (nor chains which need lubrication). Better yet, the hydraulic vertical drive system is substantially recoilless. When feeding down or retracting up against a stuck hollow stem auger string, as soon as the sticking force is overcome, the hydraulic vertical drive system does not recoil. In contrast, if a winch and cables were being used, cables stretch and the stuck hollow stem auger string (if being retracted up) can let fly after being unstuck (or after being torn apart). The cables might whips (chains would do the same) and so on. Moreover, cables can snap (so can chains). Accordingly, the hydraulic vertical drive system is better at giving precise control over the force applied to downhole tools or objects. 
   Arguably most significant of all is that, its brute power aside and in spite of being the most powerful system on the carrier/drill rig, the hydraulic vertical drive system is probably the safest. 
   Now let&#39;s return the discussion back to retracting the auger string. Hollow stem auger sections interconnect with each other by their top and bottom collars. The topmost hollow stem auger section is down fed into the bore hole by a drive cap attached to the drill drive (or extension thereof) of the drill rig.  FIGS. 1 through 3  show a drive cap and the top collar of the a hollow stem auger section. 
   When boring a well, workers usually have a mess to deal with, and understandably so, since it is a messy process in a messy environment. The auger sections typically withdraw with adhering accumulations of mud or cuttings caked inside their flutes. 
   These accumulations of mud or cuttings, if left to dry, harden as hard as sun-baked bricks, which is no surprise since basically it is the same starting material as used in sun-baked bricks. It would be desirable to clean the auger sections of such accumulations of mud or cuttings as soon as practicable after withdrawal from the bore hole, while fresh. That is, fresh accumulations of mud or cuttings are easier to clean off than if left to dry. Dried and hardened material is considerably more difficult to get to release. Also, another reason for wiping the auger sections as soon as practicable is that, such accumulations of mud or cuttings are tremendously heavy. Hence the hoisting and handling of the hollow stem auger sections would be considerably eased if unloaded of such material. 
   What is needed is a solution for this problem. 
   A number of additional features and objects will be apparent in connection with the following discussion of the preferred embodiments and examples with reference to the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There are shown in the drawings certain exemplary embodiments of the invention as presently preferred. It should be understood that the invention is not limited to the embodiments disclosed as examples, and is capable of variation within the scope of the skills of a person having ordinary skill in the art to which the invention pertains. In the drawings, 
       FIG. 1  is a perspective view of a drill rig for boring a well hole with a string of hollow stem auger sections, wherein a topmost auger section is shown above-ground and in the process of the withdrawal of the auger string as a whole (albeit, one section at a time); 
       FIG. 2  is an enlarged-scale perspective view of detail II-II in  FIG. 1 , and focusing in on tail structure of the drill rig over the open well hole which has an auger section sticking part way above-ground therefrom, and including illustration of a flute-wiping auger cleaner in accordance with the invention; 
       FIG. 3  is an enlarged-scale perspective view of the flute-wiping auger cleaner in  FIG. 2 ; 
       FIG. 4  is a top plan thereof; 
       FIG. 5  is a side elevational view thereof; 
       FIG. 6  is an enlarged-scale top plan view comparable to  FIG. 4  except zooming in on the jaws thereof; 
       FIG. 7  is an elevational view, partly in section, taken in the direction of arcuate view-line&#39;s arrows VII-VII in  FIG. 6 ; and, 
       FIG. 8  is a comparable elevational view, partly in section, except taken in the direction of arcuate view-line&#39;s arrows VIII-VIII in  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  shows a drill rig  12  and above-ground portions of a hollow stem auger section  14 .  FIGS. 2 and 3  show better that the drill rig  12  comprises a drill drive  16  which has a drive cap  18  coupled to the above-ground top collar of the hollow stem auger section  14 .  FIGS. 2 and 3  also introduce a flute-wiping auger cleaner  20  in accordance with the invention. In general, the inventive flute-wiping auger cleaner  20  is constructed of steel stock materials fastened together by a variety of means including without limitation welds, bolts, clevis as well as corresponding hairpin cotter pins and the like. In some particular instances, the construction materials might include without limitation either non-metallic knobs or, more particularly still, hard synthetic rubber for the wiper blades  24 - 26  and runner  28  as described much further below. 
   As a matter of background, and referring to  FIG. 2 , the hollow stem auger section  14  is basically a pipe (eg., the hollow “stem”  32 ) that has a helical screw  34  wound around it (and affixed to it). The interspace between coils of the helical screw  34  define a helical channel or “flute”  36  which extends up and down the length of the hollow stem auger section  14 . 
   As  FIG. 2  shows, the helical flute  36  is susceptible to fouling by adhering accumulations of mud or cuttings  38 , especially when being withdrawn. The flute  36  eventually needs to be cleared of such fouling:—for all kinds of reasons. For one, the fouling is heavy, and it is needless weight to hoist around the job-site, or to rack up on the drill rig  12 &#39;s storage racks (not shown) and haul around the countryside. For another, if the fouling is damp when fresh then the fouling is also susceptible to drying out over time:—and hence harden to the hardness of ceramic, which will render the auger section  14  inoperable (eg., the auger section  14  is transformed into a thick-walled pipe, with no helical screw  34  projecting beyond the dried-on mud, and so there is nothing to bite into the ground). It is an aspect of the invention to provide a flute-wiping auger cleaner  20  for such situations. 
   With more general reference to  FIG. 2  or  3 , the flute-wiping auger cleaner  20  comprises a draw bar  42  for inserting into a general-purpose square receiver  44  on tail structure  46  (eg., bumper or the like) of the drill rig  12 . The receiver  44  needless to say is (more or less) permanently mounted to tail structure  46  of the drill rig  12 , wherein there is a given presumption that most drill rigs of this kind have such general-purpose square receivers  44  as standard equipment. If not, such general-purpose square receivers  44  can be readily added to such drill rigs as an after-market accessory. The draw bar  42  is releasably locked to the square receiver  44  (and thereby the drill rig  12 ) by a clevis and hairpin-cotter pin combination  48  as shown. 
     FIGS. 2 and 3  show that the draw bar  42  terminates in a T-intersection with an upright structure comprising a vertical track  50 . Mounted on the vertical track  50  is vertically-traveling carriage  52 . The carriage  52  has opposed face rollers for engaging the opposite broad surfaces of the vertical track  50  as well near the margins with the lateral edges thereof, as well as opposed edge rollers for engaging those very same lateral edges of the vertical track  50 . Whereas the vertically traveling carriage  52  is free to cycle in up and down strokes on the vertical track  50  in accordance with the dominant applied force causing it to do so, the vertical carriage  52  is tightly constrained to maintain its attitude relative the vertical track  50  despite its freedom to travel up and down. 
     FIG. 3  shows better that the carriage  52  presents a special-purpose square receiver  54  opposite the vertical track  50 . Inserted in this special-purpose square receiver  54  is a cantilevered bar  56  which carries the rest of the structure constituting the flute-wiping auger cleaner  20  in accordance with the invention. The cantilevered bar  56  is releasably locked to the special-purpose square receiver  54  (and thereby the vertically traveling carriage  52 ) by another clevis and hairpin-cotter pin combination  48  as shown. 
     FIGS. 3 through 6  show better that the cantilevered bar  56  provides a vertical pivot post  58  (in actuality, bolt) for hitching on a laterally-shearing shackle assembly  60  as shown. As  FIGS. 3 and 4  show, the laterally-shearing shackle assembly  60  can be somewhat reckoned as resembling a nutcracker. The shackle assembly  60  comprises a pair of laterally-shearing jaws  61 - 62  which transition into extended handles  63 - 64  that extend away therefrom. 
   In  FIG. 3 , the nearside jaw is the relatively upper jaw  61  and the farside jaw is the correspondingly lower jaw  62 . That is, the nearside jaw  61  travels laterally in a relatively overhead plane relative the plane which the farside jaw  62  travels in, for purposes to be more particularly described below. 
     FIGS. 3 through 5  show that it is an aspect of the invention to clamp the jaws  61 - 62  on the hollow stem auger section  14  in a relatively latched position as shown, and by a releasable latching system  65 . The releasable latching system  65  comprises an extensible tension link  66 , a lever  68 , and a latch  72 . The extensible tension link  66  extends from an origin end attached to the lower handle  64  to a terminal end comprising an eye loop  73 . 
   More particularly, an example embodiment of the extensible tension link  66  comprises a safety-type draw-bar tension spring  74  having one end attached to an eye bolt  75  attached to the lower handle  64  and an opposite end that provides immediately or intermediately for the eye loop  73  (the drawings show one or more oval links that culminate in the ultimate eye loop  73 ). 
   The lever  68  comprises rod stock extending between a crank end  76  and a hook end  78 . The lever  68  furthermore has middle portion which is secured to a strap  79  that is secured to a mount on the upper handle  63 . The crank end  76  serves as the input end. The hook end  78  provides the output motion resulting from the input motion. The strap  79  serves as the fulcrum across which the input motion is converted into the output motion. 
   The latch  72  comprises a J-shaped piece of flat bar stock, having a hoop end pivotally connected to a bolt  81  or stud fastened to the mount on the upper handle  63 . The bight of the J-shaped latch  72  is free to be manipulated about by a grip  82  extending off the J-shaped latch  72  where its bight transitions into the stem thereof. 
     FIGS. 4 and 6  through  8  show better the preferred configuration of the wiper blades  24 - 26 . As mentioned above, preferably the wiper blades  24 - 26  are constructed of hard synthetic rubber. That way, the wiper blades  24 - 26  are fairly stiff but will yield to particularly tough obstacles by resilient flexion.  FIGS. 4 and 6  show that the preferred configuration of wiper blades  24 - 26  comprises a set of three (3) blades that are anchored by clamping brackets  84 - 86  to the jaws  61 - 62  in an angularly distributed distribution as shown. The blades  24 - 26  are disposed to project a wiping edge into one coil of the helical channel that constitutes the flute  36  of the hollow stem auger section  14  as shown. 
   With continued reference to  FIGS. 4 and 6 , the set of three (3) blades  24 - 26  comprises a leading blade  24 , a trailing blade  26 , and an intermediate blade  25 . These descriptive designations for the wiper blades  24 - 26  presumes (without limitation) that the blades  24 - 26  are operational to clean the flute  36  from the top end, onward down to the bottom end (ie., from the end closest to the coupling with the drill rig  12 &#39;s drive cap  18 , onward toward the bit end). The leading blade  24  is arranged on an oblique angle of attack relative to the oncoming onslaught of adhering accumulations of mud or cuttings  38 . The intermediate blade  25  is arranged on a more or less radial axis (ie., normal axis) and therefore perpendicular to the left-over onslaught of adhering accumulations of mud or cuttings  38 . The trailing blade  26  is arranged on an acute angle of attack to the residual adhering accumulations of mud or cuttings  38 . 
   Each of the three (3) blades  24 - 26  is secured or clamped to one or the other of the jaws  61 - 62  by its own respective bracket  84 - 86 . The leading blade  24  is secured or clamped by an L-shaped bracket  84  to the lower jaw  62  at about the eight o&#39;clock position (eg., relative an imaginary clock dial superimposed over  FIG. 4  or  6 ). The trailing blade  26  is secured or clamped by an L-shaped bracket  86  to not the lower jaw  62  but the upper jaw  61 , and at about the eleven o&#39;clock position. The intermediate blade  25  is secured or clamped not by an L-shaped fabrication but by a straight bracket  85  (eg., flat bar stock). The intermediate blade  25 &#39;s bracket  85  could be optionally secured or clamped to either the upper or lower jaw  62 . The preferred embodiment has the intermediate blade  25 &#39;s bracket  85  secured or clamped to the upper jaw  61 , and at about the two o&#39;clock position. 
   Each bracket  84 - 86  is arranged to compliment the angle of attack of the respective blade  24 - 26 . That is, the leading blade  24  that is arranged on the oblique angle of attack is held by its L-shaped bracket  84  such that the blade  24  and bracket  84  are arranged to be pushed out by particularly heavy, thick and/or gummy accumulations of mud or cuttings  38 . The intermediate blade  25  and its bracket  85  are arranged to present the intermediate blade  25  as a perpendicular surface for scraping the left-over onslaught of adhering accumulations of mud or cuttings  38 . Accordingly, it is held on more or less a radial axis by its straight or cantilevered bracket. 
   The trailing blade  26  that is arranged on the acute angle of attack is held by its L-shaped bracket  86 , except this L-shaped bracket  86  is flipped relative to the leading blade  24 &#39;s L-shaped bracket  84  such that this orientation of blade  26  and L-shaped bracket  86  is designed to increase the digging pressure of the trailing blade  26  accordingly into the onslaught of the residual adhering accumulations of mud or cuttings  38 . 
     FIG. 4  shows best the progressive work of the three (3) blades  24 - 26  according to their respective angle of attacks and respective designs of their brackets  84 - 86 . The leading blade  24  is designed to not only scrape off adhering accumulations of mud or cuttings  38  but also ride out away from a particularly heavy, thick and/or gummy boundary layer of such. As the leading blade  24  is pushed away (which is down in  FIG. 4 ), the movement of the lower jaw  62  away from the central axis of the auger section  14  only increases the tension in the extensible tension link  66 . This in consequence increases the pull on the upper jaw  61  in towards the central axis of the auger section  14 , which increases the digging pressure of the trailing blade  26 . 
   As the intermediate blade  25  encounters the left-over and particularly toughly stuck-on boundary layer of adhering accumulations of mud or cuttings  38 , it too might not get all of that stuff (some, but not all) and in result be pushed radially out just as was the leading blade  24 . But it will be seen in  FIG. 4  that radial outward movement of the intermediate blade  25  causes the jaws  61 - 62  as a unit to more or less move to the right in  FIG. 4  (ie., towards the drill rig  12 ). That movement likewise increases the digging pressure of the trailing blade  26 . 
   The trailing blade  26  is the last-in-line of the blades  24 - 26  to tackle the residual adhering accumulations of mud or cuttings  38 . The trailing blade  26  is arranged to attack the residual adhering accumulations of mud or cuttings  38  at an acute angle. If the residual boundary layer is particularly toughly stuck-on, rather than being arranged to slip outwards, the leading blade  24  is arranged to dig into with even more force. Moreover, the L-shaped bracket  86  therefor is turned to enhance the digging effect. 
     FIGS. 4 ,  6  and  8  show that the lower jaw  62  carries a runner  28  in close association with the leading blade  24 . Like the wiper blades  24 - 26 , preferably the runner  28  is produced of hard, synthetic rubber material.  FIG. 8  shows that the runner  28  is disposed above the leading blade  24 , and projects into the helical channel that constitutes the flute  36  for the auger section  14 . 
   Briefly, as a matter of background, the auger section  14 &#39;s screw  34  winds around in a helical path according to right-hand thread. Therefore, to bore into the earth the auger section  14  would be spun in the forward direction, which is the same for right-hand thread as being twisted clockwise (when viewed from above). Correspondingly, to spin the auger section  14  out of the bore hole it would be spun in the reverse direction, which is the same for right-hand thread as being twisted counterclockwise. 
   Given the foregoing, the runner  28  and leading wiper blade  24  are arranged to project into a common same coil of the helical channel that constitutes the flute  36  for the auger section  14  (a “coil” comprises one full circuit of the screw  34  or, according to context, flute  36 :—wherein the screw  34  or flute  36  as a whole comprises numerous coils, and any given coil is any arbitrary full circuit of the screw  34  or, according to context, flute  36 ). 
   The runner  28  is disposed to ride under the lower helical surface of the screw  34 , as shown best in  FIG. 8 . That way, when the auger section  14  is being spun in reverse—which is the same as being twisted in the counterclockwise direction—the runner  28  is pushed down against by the screw  34 &#39;s lower helical surface. In consequence, this drives the shackle assembly  60  and carriage  52 —as a unit—down the auger section  14 , with the wiper blades  24 - 26  plowing through the adhering accumulations of mud and cuttings  38  in the progressive fashion as described above. 
     FIGS. 4 and 6  show that the runner  28  has terminal edge formed with a recess  87  in the shape of a segment of a circle (ie., that part of a circle bounded by a chord and an arc). The arc edge of this recess  87  is intentionally gapped away from the outer lateral (ie., cylindrical) surface of the auger stem  32  by gap  89  as shown. It is a design preference that the runner  28  not rub against the lateral side of the auger stem  32 , but instead, ride under the screw  34 &#39;s lower helical surface. 
     FIGS. 7 and 8  show the relative positional placements of the three (3) blades  24 - 26 . This positional placement is more particularly in respect to the helical channel that constitutes the flute  36 . The blades  24 - 26  are alike in being staged to service a respective crosswise axis relative to the flute  36  (which crosswise axes are, given the upright orientation of the auger section  14  in  FIGS. 7 and 8 , the vertical spacing between adjacent coils of the screw  34 , and as parallel to the axis of the cylindrical auger stem  32 ). 
   Briefly—in review—the leading, intermediate and trailing wiper blades  25  and  26  are angularly staged in the eight, two and eleven o&#39;clock positions respectively (when given the viewpoints of  FIG. 4  or  6 ). Correspondingly—the leading, intermediate and trailing wiper blades  25  and  26  are angularly staged in the eight, two and eleven o&#39;clock positions respectively are axially staged (eg., elevation-wise) progressively to match the helix of the flute  36 . Hence relative the leading blade  24  is, the intermediate blade  25  is higher and the trailing blade  26  is highest. 
   However, none of the foregoing deals with the subtle positional placements of the three (3) blades  24 - 26  which  FIGS. 7 and 8  show. To the contrary,  FIGS. 7 and 8  show that none of the blades  24 - 26  is so wide as to occupy the whole cross-wise span of the channel of the flute  36 . Instead, all the blades  24 - 26  are a little undersized. It may appear that the leading blade  24  is intentionally undersized to accommodate for the inclusion of the runner  28 , but that is not necessarily the primary design intention for the leading blade  24 . Indeed, the intermediate and trailing blades  25  and  26  are likewise undersized, and they do not have to accommodate anything like the runner  28 . The primary design intention for the blades  24 - 26  being undersized is something different. 
     FIG. 8  shows that the leading blade  24  is positioned so that its lowest corner scrapes tightly inside the low intersection between the helical screw  34  and the cylindrical lateral surface of the auger stem  32 . In contrast,  FIG. 7  shows that the trailing blade  26  is positioned so that its highest corner scrapes tightly inside the high intersection between the helical screw  34  and the cylindrical lateral surface of the auger stem  32 .  FIG. 7  also shows that the intermediate blade  25  occupies a middle position inside the channel of the flute  36 , gapped away from both the high and low intersections of the helical screw  34  and the cylindrical lateral surface of the auger stem  32 . 
   The primary design intention behind this is at least twofold. For one thing, because of the respectively different angles of attack of the three blades  24 - 26 , each blade  24 - 26  is positioned in the channel of the flute  36  where it is least likely to be interfered with by the warp of one, the other or both of the upper and lower helical surfaces of the screw  34 . In other words, it is not practical to size the blades  24 - 26  for full-channel width across the flute  36  or there would be clearance problems. One, the other or both the upper and lower helical surfaces of the screw  34  would pinch or bind the blades  24 - 26 . Hence the blades  24 - 26  are undersized to prevent this, and then logically positioned such that whole channel is serviced by at least one or another of the blades  24 - 26 . 
   For another thing, the drawing figures illustrate an idealized screw  34 . That is, the illustrated screw  34  is perfectly helical, and the channel of the flute  36  is uniform at every span. In the real world, many factors conspire against this idealized depiction of the screw  34  and channel of the flute  36 . One factor includes variances introduced during manufacturing. The screw  34  might possibly be fabricated to fairly near perfect proportions, but after being welded onto the cylindrical lateral surface of the auger stem  32 , imperfections are no doubt introduced. 
   More significantly, after extended use, the helical screw  34  experiences all kinds of hardship. It may be called on to course through not only rich soil or sand but also rock or reinforced concrete and so on. After extended use, the helical screw  34  shows all kinds of scars inflicted by all kinds of insults, and is far from perfect. In various places the screw  34  will be bent by hard but irregularly hard substrate, filed down by abrasion, bent by engulfing hard intrusions in an otherwise soft substrate, and so on. 
   Hence  FIGS. 7 and 8  show relative positional placements for the three (3) blades  24 - 26  which, in accordance with a preferred design intention, accommodates scarred auger sections  14  the scarring of which results from normal wear and tear in a tough use environment. 
   Pause can be taken now to transition to describing a preferred manner of use of the flute-wiping auger cleaner  20  in accordance with the invention.  FIG. 2  shows the string of auger sections  14  being retracted from the bore hole by the drill drive  16  of the drill rig  12 . The auger cleaner  20  is shown already engaged. At an earlier time, the auger cleaner  20  would have been disengaged. The extensible tension link  66  would have been slack and dangling down freely. 
   To engage the disengaged auger cleaner  20 , workers preferably take the following steps. That is, a worker would grab the laterally-shearing handles  63 - 64  with both hands, open the jaws  61 - 62  wide, and lift the auger cleaner  20  to an elevation not only at a high point on the fouled auger section  14  but also to an elevation where the vertically-traveling carriage  52  is near the top of the vertical track  50 . Then the worker closes the jaws  61 - 62  such that the wiper blades  24 - 26  insert inside the channel of the flute  36 . The worker (or a helper) next grabs the crank end  76  of the lever  68  as well as the eye loop  73  of the extensible tension link  66  and fishes the hook end  78  to catch the eye loop  73 . Once caught, the worker handling the crank end  76  then forces the crank end  76  against the strap  79  that acts as the fulcrum to spread the extensible tension link  66 , at the same time grabbing the grip  82  on the latch  72 , and then latches the crank end  76  in a clamped position as shown in  FIG. 2  or  3 . 
   Given the foregoing, the auger cleaner  20  is set in place to do its job. Preferably the worker runs the drill rig  12 &#39;s drill drive  16  in reverse. The auger cleaner  20 &#39;s runner  28  forces the shackle assembly  60  to descend in elevation such that the wiper blades  24 - 26  encounter and scrape off any adhering accumulations of mud or other cuttings  38 . At the same time, the vertically-traveling carriage  52  descends smoothly down the vertical track  50  while concurrently supporting the shackle assembly  60  in its attitude. At the end of the downstroke for the shackle assembly  60 , the worker switches the drill rig  12 &#39;s drill drive  16  to OFF, disengages the shackle assembly  60 , and then uses the drill rig  12 &#39;s drill drive  16  to hoist up the string of auger sections  14  another five feet or so ( ˜ 1½ meters) or so. 
   As an aside, hollow stem auger sections  14  are conventionally a standard five feet in length ( ˜ 1½ m) in length. Preferably the vertical track  50  of the auger cleaner  20  is a corresponding five and a-half feet ( ˜ 1⅔ meters) or so. That way, each pass with the auger cleaner  20  results in cleaning one auger section  14 , which can then be detached from the string as a whole and racked up on the drill rig  12 &#39;s storage racks therefor (not shown). Successive sections  14  of the auger string are cleaned as described. 
   By design intention, one method of cleaning the auger sections  14  contemplates down strokes which are induced by operating the drill rig  12 &#39;s drill drive  16  in reverse, then up strokes which are manipulated manually:—as by manually disengaging the shackle assembly  60  in a low position, hydraulically hoisting up the string of auger sections  14  by the drill rig  12 &#39;s drill drive  16 , and then re-engaging the shackle assembly  60  manually at a high position. 
   An alternative method of cleaning the auger sections  14  contemplates leaving the auger cleaner  20 &#39;s shackle assembly  60  clamped ON for the duration, wherein the step of hydraulically hoisting up the string of auger sections  14  by the drill rig  12 &#39;s drill drive  16  is done so by one stroke at a time so that the shackle assembly  60  and carriage  52  combination is passively carried up the vertical track  50  by the increment of one short hoist of the drill rig  12 &#39;s drill drive  16  at a time (eg., about five feet or 1½ meter increments at a time). Needless to say, the drill drive  16 &#39;s spinning operation is most preferably switched OFF during the hoist operation. 
   This disclosure incorporates by reference the disclosure of commonly-invented, commonly-owned co-pending U.S. patent application Ser. No. 11/546,924, filed Oct. 11, 2006, as well as all its priority applications, as if such were set forth in full fully next. 
   The invention having been disclosed in connection with the foregoing variations and examples, additional variations will now be apparent to persons skilled in the art. The invention is not intended to be limited to the variations specifically mentioned, and accordingly reference should be made to the appended claims rather than the foregoing discussion of preferred examples, to assess the scope of the invention in which exclusive rights are claimed.