Abstract:
A flightless rock auger is used for drilling postholes through rock with the use of hydraulic pressure and at slow revolution per minute. The rock auger is used in combination with a conventional flighted auger used for drilling postholes in dirt and clay. During a posthole drilling operation, the rock auger is substituted for a conventional flighted auger as needed for drilling through and removing rock or other hard material such as concrete from the posthole. The rock auger is designed for use at very low revolutions per minute and can function utilizing only the weight of the auger; however, the rock auger is designed for use with pressure drilling units as well for cutting a circular hole through the rock and forming a plug which is to be lodged in the cavity of the rock auger cylinder to be removed from the posthole. The quick connection enables the shaft of a pressure drill unit to engage the flightless auger to be quickly substituted for the rock auger to facilitate fast removal of soft dirt from the posthole. A pilot drill bit can be disposed within the cutting head for extending outwardly pass the cutting edge thereof for starting the hole, breaking up rock, and holding the auger in position during the drilling operation. A portion of the cylindrical body can be removed to allow quick clearance of the plug.

Description:
This is a Continuation-In-Part of U.S. application Ser. No. 09/684,821 filed on Oct. 10, 2000 which is C-I-P from Ser. No. 09/066,194 filed on Apr. 24, 1998 which issued as U.S. Pat. No. 6,129,163 on Oct. 10, 2000; Provisional Application Serial No. 60/257,054 filed on Dec. 20, 2000; Ser. No. 60/203,061 filed on May 9, 2000; and Ser. No. 60/185,664 filed on Feb. 29, 2000 all of which are incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a flightless rock auger suspended from a derrick and powered by a shaft linked to a power source for removing plugs of rocks from post holes. 
     Poles for power lines and communication purposes are required to be vertical and arrange din straight lines. The poles may be planted in positions which are relatively inaccessible. A crane may be utilized for providing an outreaching means. Typically a digger derrick consists of a telescopic mobile crane from which is suspended a torque head. A flighted auger is suspended from the torque head and utilized for drilling in soil containing loose rock. The digger derrick is advantageous for extending the auger to the desired location. The auger may be stowed in a fixed position or extended in a telescoping position as needed to reach the desired location for drilling the hole. 
     Depending on the nature of the digging device, its digging element, or auger, torque head or hydraulic pressure is typically exerted on the digging element via air or oil hydraulic pressure exerted by the crane or cylinder in cooperative engagement therewith for forcing the digging element into the earth. 
     Although the conventional flighted auger is adequate for drilling through soil, or even soil with loose rock, the drilling operation must be suspended upon hitting a large rock or rock ledge because the flighted auger cannot penetrate the hard rock surface. The flighted auger is then lifted out of the hole and conventional methods of removing the obstruction with a steel shaft, crowbar, or explosive charge are used to break-up the hard rock. The flighted auger is then lowered into the hole to remove the loose rock. 
     A considerable amount of time is lost during the rock break-up and removal procedure. Moreover, an effort is continually being made to minimize work with explosives due to the liability of injury to workers and/or damage to residents or businesses in the area which may be in the area of the blasting zone and susceptible to rock or vibration damage. 
     SUMMARY OF THE INVENTION 
     The present invention achieves the above objects by providing a flightless rock auger for drilling postholes through rock and hardpan. 
     The present invention provides a flightless rock auger having a cylindrical hollow cutting head and a plurality of teeth extending from the lower periphery thereof. A support member extends across a portion of the cylindrical hollow cutting head providing a means for cooperative engagement with a shaft extending outwardly therefrom. A quick disconnect coupling is disposed upon the distal end of the shaft or in the case of the pressure digger unit a connection is formed at the top of the body for cooperative engagement with the shaft; of a pressure digger, usually of square or hexagonal or octagonal configuration. 
     One preferred embodiment of the flightless rock auger system for use with a drilling rig includes a flightless rock auger having a cylindrical hollow cutting head with a plurality of cutting teeth extending from the bottom edge of the cutting head. A support member extends across a portion of the cylindrical hollow cutting head providing a means for cooperative engagement with a vertical drive shaft extending outwardly therefrom. A quick disconnect coupling is disposed upon the distal end of the shaft. A means for rotating the drive shaft such as a mechanical or fluid drive may also power the hydraulic mechanism for lifting and lowering the drive shaft which may utilize its own weight for exertion of downward pressure onto the hard substrate. Embodiments utilizing a coupling affixed directly to the top of the cutting head are well suited for use with pressure drilling rigs whereby force may be applied to the auger to provide quicker drilling. 
     A method of removing hard substrate from a posthole, using a flightless rock auger with a drilling rig simply requires the attaching a flightless rock auger having a cylindrical hollow cutting head and a plurality of cutting teeth extending from the bottom edge of the cutting head. A support member extends across a portion of the cylindrical hollow cutting head providing a means for cooperative engagement with a vertical drive shaft extending outwardly therefrom formed integrally therewith, or disposed therein from a pressure drill. 
     On the shaft models, a quick disconnect coupling is disposed upon the distal end of the shaft to means for rotating the drive shaft. On some pressure drilling flightless rock augers the shaft of the pressure drill rigs cooperatively engage a coupling mounted to the top of the auger body with a reinforced connections. The flightless rock auger is lowered into a posthole containing a hard substrate and resting the flightless rock auger onto the hard substrate. The auger is rotated at a very low rpm of up to 60 rpm, but more preferably up to 30 rpm and most preferably in a range of from between about 3 rpm to about 10 rpm forming a plug of hard substrate inside of the cylindrical body of the flightless rock auger. Lifting the flightless rock auger and the plug from the posthole is simple and the plug of the hard substrate is removed from the flightless rock auger head. The flighted auger is then substituted for removing soil from the posthole. 
     The flightless rock auger comprises a cylindrical head defining a plurality of teeth extending downwardly from the periphery of the bottom edge at a selected forward angle. The top of the head is connected to a shaft having a quick disconnect adapter. 
     The rock auger is utilized in combination with a conventional flighted auger used for drilling postholes in dirt and clay. During a posthole drilling operation, the rock auger is substituted for the flighted auger when needed to drill through and remove rock or other hard material such as concrete from the posthole. The rock auger is designed for use at very low revolutions per minute and can utilize only the weight of the auger and shaft and does not require any additional hydraulic pressure for cutting a circular hole through the rock and forming a plug which is be lodged in the cavity of the rock auger cylinder to be removed from the posthole. Of course, most trucks or drilling rigs are equipped with hydraulic means for exerting pressure on the cutting head to increase the cutting rate and is often utilized with the shaft and cutting head and usually utilized with the pressure drilling head having a quick disconnect near the top of the cutting head body. The quick connection shaft enables the conventional flighted auger to be quickly substituted for the flightless rock auger to facilitate fast removal of soft dirt from the posthole. The rock auger provides a means for utility companies to utilize a means for drilling postholes for electric poles, telephone poles, pilings, and the like without the use of explosives; thereby providing a safer means of excavation. 
     When the drilling operation encounters rock, rather than blasting through the rock with explosives, the flightless rock auger can be fitted onto the torque head of a conventional drilling shaft and used to drill through the rock. A plug may be formed in the head by the drilling operation; however, the plug is removed by using had tools which fit into openings formed in the top end of the drilling head, or be forced through a side opening thereof. 
     A preferred embodiment of the present invention includes at short or long shaft extending from the body with a quick disconnect distal end, a cylindrical body and drill head having a greater diameter than the body wherein a plurality of teeth extend downward at an angle from the outer edge of the drill head. 
     More particularly, the flightless rock auger is designed for removing plugs of hard material from post holes. The rock auger includes a cylindrical hollow cutting head having a hollow cylindrical body defining side walls connecting a top end defining an upper peripheral edge and a lower open end defining a lower peripheral cutting edge including a plurality of teeth extending from the lower peripheral edge. The top end of the hollow cylindrical body can include at least one support member extending across at least a portion of the top end joining the side walls. A shaft having a diameter less than the cutting head includes a proximal end connecting to the at least one support member and having an opposing distal end extending therefrom, whereby the shaft is integrally connected to the auger body, or in the case of the pressure drill embodiment, cooperatively engages the connection at the top of the hollow cylindrical body. The long shaft quick disconnect coupling disposed upon the opposing distal end of the shaft may include means for a floating providing limited vertical movement therebetween which may consist of a coupling having a slotted attachment joint or other connection allowing for some “play” within the coupling, or the coupling may use a pin extending though a corresponding shaped and sized hole through the shaft and coupling to provide a tight fit and limited movement. 
     Of course, the power drive shaft of the auger drive unit can also be connected to the shaft of the auger by a coupling which limits or even eliminates any “play” and provide a tight cooperative engagement therebetween. The auger and cutting head will still “float” in that only the weight of the auger will be necessary to cut through the rock substrate. If desired the cutting may be faster by also letting the power drive boom weight rest on the auger thereby floating on the rock substrate during the drilling process. Of course, applying downward pressure to the auger by use of the boom is an option to increase the cutting rate; however, unnecessary to obtain good performance. Thus, the pressure drill model provides rapid cutting motion through the substrate. 
     Accordingly, it is a principal object of the present invention to provide a flightless auger device for digging through hard rock. 
     It is another object of the present invention to provide an flightless auger which is capable of drilling through rock and forming a plug removable from the flightless auger. 
     It is another object of the present invention to provide a flightless auger utilizing an attachment means which is interchangeable with the attachment means typically used with conventional flighted augers for drilling operations. 
     It is therefore another object of the present invention to design a flightless auger for use at very low revolutions per minute (rpm) to maximize safely and prevent damage to the equipment. 
     It is an object of the present invention to provide an adapter extending from a shaft for use with a torque head of a drilling derrick. 
     Another object is to provide a flightless auger having teeth extending outward at a forward angle. 
     It is another object to provide a flightless auger having a drill head portion utilizing an end diameter of greater diameter than the plug receiving inner diameter. 
     It is yet another object of the present invention to utilize a plurality of diagonal ribs to minimize suction between the exterior of the drilling head and the walls of the drilled hole. 
     It is yet another object of the present invention to provide an access port in the top end of the drilling head for removal of the rock plug formed therein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein: 
     FIG. 1 is a front perspective view of the present invention showing the flightless rock auger with a shaft, and a cylindrical body forming a drill head with a plurality of teeth extending form from the outer edge of the drill head; 
     FIG. 2 is a side perspective view of the invention of FIG. 1; 
     FIG. 3 is a top view of the invention of FIG. 1; 
     FIG. 4 is a perspective view of the invention of FIG. 1; 
     FIG. 5 is a bottom view of the invention of FIG. 1; 
     FIG. 6 is a partial cutaway view of the invention of FIG. 1 shown drilling through rock forming a plug therein; 
     FIG. 7 is a perspective view of an embodiment of a mobile drilling rig utilizing the present invention; 
     FIG. 8 is a perspective view of another embodiment of a life assembly suspending the present invention above the ground; 
     FIG. 9 is a perspective front view of an alternate embodiment of a flightless rock auger showing a cutting head of a flightless auger including a pilot bit centered within the cylindrical body extending past the cutting teeth; 
     FIG. 10 is a perspective side view of the embodiment of the flightless rock auger of FIG. 9; 
     FIG. 11 is a top view of the flightless rock auger embodiment of FIG. 9; 
     FIG. 12 is a perspective view of the flightless rock auger embodiment of FIG. 9 showing the pilot bit attachment through the access port in the top of the cylindrical body; 
     FIG. 13 shows a perspective bottom view of the flightless rock auger embodiment of FIG. 9; 
     FIG. 14 is an exploded perspective view of the flightless rock auger embodiment of FIG. 9 showing the pilot bit shaft and tip; 
     FIG. 15 is a cutaway perspective view of the flightless rock auger embodiment of FIG. 9 showing the pilot bit therein; 
     FIG. 16 is a front perspective view of another alternate embodiment of the flightless rock auger of the present invention showing the shaft with a quick disconnect distal end, a cylindrical body and drill head having a greater diameter than the body wherein a greater number of teeth extend downward at an selected angle from the outer edge of the drill head, and a section of the cutting head removed to facilitate removal of the plug; 
     FIG. 17 is a perspective side view of the invention of the flightless rock auger embodiment of FIG. 16; 
     FIG. 18 is a perspective top view of the flightless rock auger embodiment of FIG. 16 
     FIG. 19 is a perspective view of the flightless rock auger embodiment of FIG. 16 showing the double layer sidewall which may be optionally utilized to form a cutting edge on the side of the cutting head and whereby the cylindrical body may be sized to be smaller than or as large as the cutting head; 
     FIG. 20 is a perspective bottom view of the flightless rock auger embodiment of FIG. 16 showing the angled teeth; 
     FIG. 21 is a perspective front view of the flightless rock auger embodiment of FIG. 16 showing the edges of the double sidewall cutaway portion of the body extending around the periphery thereof a selected length forming a double cutting edge; 
     FIG. 22 is perspective front view of the flightless rock auger embodiment of FIG. 16 including the pilot bit as shown in FIG.  9  and showing the edges of the double sidewall cutaway portion of the body extending around the periphery thereof a selected length forming a double cutting edge; 
     FIG. 23 is a perspective side view of the flightless rock auger embodiment of FIG. 16, showing a vertical cutting edge along the cutaway portion of the cylindrical body; 
     FIG. 24 is a perspective side view of the flightless rock auger embodiment of FIG. 16, showing an angled cutting edge along the cutaway portion of the cylindrical body; and 
     FIG. 25 is perspective top view of another embodiment of the flightless rock auger showing a coupling mounting directly to the top of the cylindrical body; 
     FIG. 26 is perspective bottom view of the flightless rock auger embodiment of FIG. 25 showing the angled teeth; 
     FIG. 27 is a perspective side view of the flightless rock auger embodiment of FIG. 25, showing a vertical cutting edge along the cutaway portion of the cylindrical body; 
     FIG. 28 is a perspective side view of the flightless rock auger embodiment of FIG. 25, showing an angled cutting edge along the cutaway portion of the cylindrical body; and 
     FIG. 29 is a perspective cutaway view of the flightless rock auger embodiment of FIG. 25 shown with a pilot bit and side edges extending into a bore formed in rock and soil. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The flightless rock auger  10  with quick attachment coupling  11  of the present invention is manufactured from readily available materials and simple in design. The preferred embodiment is comprised of metal, more particularly steel. The rock auger  10  is mounted on construction equipment such as hydraulic drilling rigs. A drive shaft  12  in communication with a drilling rig motor  14  or circulation of a hydraulic fluid from a pump on the drilling rig  16  may be used to drive the hydraulic motor  18  of the construction equipment. 
     Referring now to the drawings, FIGS. 1-8 refer to the present invention including a standard drive shaft  12  utilizing a quick disconnect coupling  11  extending from the distal end  13  of the shaft  12 . The shaft  12  is centrally aligned with the axis of the hollow cylindrical body  20  and secured to the proximal end, or top end of the cutting head  24  opposite the open end  26  having the cutting edge. The top end is at least partially enclosed by a cross member  21  to provide structural strength. One or more reinforcements member such as the triangular members  28  may be welded to the shaft  12  and the top cross member  21  of the cutting head  24  to provide additional lateral and rotational strength. 
     As shown in FIGS. 3 and 4, the distal end  13  of the shaft  12  is typically tubular having a circular cross-sectional dimension, wherein a quick disconnect cylindrical coupling  11  may be welded, pressed, screwed, or friction fitted to the distal end  13  of the shaft  12 . The cylindrical coupling  11 , preferably is shaped having a female socket end  30  for cooperative engagement with the male end of a drive shaft  32  of a motor  14  or pump drive unit  18 . A pin  33  may extend through the female socket end  30  and drive shaft  32  to provide the cooperative engagement; however, the preferred embodiment utilizes a coupling having a female socket end  30  sized and having a selected cross-sectional shape, to mate with a male drive shaft  32  having a square, hexagon, octagon or other shape for providing additional stability, rigidity, and stability to the connection therebetween. Moreover, a preferred embodiment can include a pin  33  which slides through a vertically disposed key way slot  34  to secure the quick connect coupling  11  to the drive shaft  32  of the drilling rig  16  permitting limited vertical movement therebetween as best shown in FIG. 3 or the slot may be in the form of a hole or corresponding shape and size of the pin  33  to minimize “play”. A protective collar or flange  36  may extend circumferentially around the coupling  11 . A key  38  may be inserted into a groove or orifice in the shaft  12  to provide an alignment indicator so that a user standing below the drilling boom  40  can look upward and align the key way slot  34  of the rock auger with the key way of the pump motor drive shaft  32  for quick coupling of the units. The key  38  also provides an easy means to count the revolutions per minute of the auger  10 . 
     The rock auger can have a connecting collar defining a flange  124  for connecting to a complimentary power drive flange and a protective flange circumscribing the shaft therebelow to protect the users. 
     The cutting head  24  is formed from a hollow cylindrical body  20  open at its lower open end  26 . A plurality of conical shaped teeth  44  extend from generally rectangular shaped projections  46  extending from the outer peripheral edge  48  of the cutting head body  20 . The conical shaped teeth  44  are equally spaced apart and angled slightly in a forward direction. The teeth  44  may also be angled inwardly or outwardly slightly to protrude pass the peripheral edge  48  of the hollow cylindrical body  20 . For instance, the series of teeth  44  at the bottom edge of the hollow cylindrical body  20  may be alternately inwardly and outwardly displaced from the plane of the hollow cylindrical body  20 . The displacement of the teeth  44  is such that the cut or kerf made in the rock or other hard substrate is slightly wider than the thickness of the hollow cylindrical body  20  to aid in extraction of the cutting head  24  from the hard substrate. The teeth  44  may also be provided with additional material so that each tooth is wider than the thickness of the side walls of the hollow cylindrical body  20 . 
     One preferred hollow cylindrical body embodiment comprises an upper section  50  and lower section  52 , wherein the lower section  52  defines a greater exterior diameter than the upper section  50  to facilitate removal of the cutting head  24  from the posthole and reduce or prevent binding during the drilling process. Moreover, a hole, slot, slit or other opening  51  is optionally cut or formed into the upper section  50  to allow water to exit the head during the cutting operation and avoid causing a suction making removal of the rock plug difficult. 
     The flightless auger  10  is designed for interchangeable use with a conventional flighted auger used for removal soil from the post holes. The quick disconnect feature of the flightless auger  10  makes the interchangeable augers practical to use together without wasting time. Upon hitting a hard substrate such as a rock ledge, the flighted auger can be disengaged in minutes and the flightless rock auger  10  attached to the drilling rig. The flightless auger  10  is lowered and raised with the hydraulic boom so that only the weight of the auger  10  exerts pressure on the rock substrate defining floating pressure. Although pressure may be exerted on the auger  10  it is not necessary in that the weight of the auger  10  is sufficient to cut through hard material such as rock ledges. Usually it is sufficient to lower the flightless rock auger  10  into the hole and letting it rest or “float” on the hard substrate. Optionally the weight of the power unit and boom may rest on the auger  10  adding additional weight; however, the auger is still considered to “float” in that no hydraulic pressure is needed to cut through the rock. Because the auger  10  is operated at a very low rpm, typically up to 15 revolutions per minute, (“rpm”), and preferably about 3 to 10 rpm, little dust is formed in the operation. Moreover, the wear and tear on the equipment is reduced if not eliminated as compared with the conventional drilling methods. This provides a very safe method of forming a plug of material within the cylindrical cutting head  24  for removal from the posthole. Upon breaking through the hard substrate and forming a plug therefrom, the flightless rock auger  10  is lifted from the hole and the plug removed by prying the plug out of the cylindrical body  20  with the use of pry bars which are extended into the openings  54  in the top of the cylindrical cutting head  24 . 
     As shown in Figures, the flightless rock auger shows a cutting head having a row of removable or replaceable teeth, preferably conical teeth, extending from the bottom edge of angled sockets mounted by welding onto the bottom of he cutting head. The sockets and teeth can be oriented in a staggered configuration with teeth angled forward at from 20 to 50 degrees and preferably about 35 degrees. Every third tooth can be angled up to 30 degrees in the horizontal plane outwardly pass the edge of the cutting head, angled up to 30 degrees in the horizontal plane inwardly pass the edge of the cutting head, or in alignment with the edge of the cutting head. 
     The teeth in the cutting head can be disposed at an angle or up to 45 degrees, and preferable at an angle of from about 20 degrees in and out from the sidewall edge. The teeth may be disposed at up to 90 degrees and more preferably from 70 to 75 degrees, and most preferably at about 73 degrees at a forward angle. FIG. 22 is a photograph showing a side view of a cutting head incorporating 18 teeth on an 18 inch diameter auger vs. 13 teeth on the initial embodiment of the invention providing a smoother cutting operation and smoother sidewalls on the hole formed thereby, also the cutting teeth are disposed at an angle extending inwardly and outwardly at 20 degrees which varies from the original embodiment, finally the cutting teeth are mounted in a range of from 70 to 75 degrees and preferably at about 73 degrees facing forward. 
     A preferred embodiment of the flightless rock auger comprises a cutting head can incorporate 18 teeth on an 18 inch diameter head or 13 teeth on an 18 inch diameter head. Eighteen teeth provide a smoother cutting operation and smoother sidewalls on the hole formed thereby. Also the cutting teeth can be disposed at an angle extending inwardly and outwardly preferably at about 20 degrees and be mounted in a range of from 70 to 75 degrees and preferably at about 73 degrees facing forward. 
     Moreover, as best illustrated in FIGS. 9-14, the cutting head of the auger includes a center drill bit or pilot bit  100 . The pilot bit  100  can be removably mounted via a socket with a spring loaded ball arrangement, a pin extending through a shaft and coupling arrangement, or as shown in the drawings, have a base  102  attached to the support member. The support member connecting the side walls of the upper portion of the cutting head includes means for attachment defining a pair of bolts extending therethrough for attachment to the cutting head support member. The bottom of the base of the center drill bit can include a pair of side flanges  122  for alignment and cooperative engagement with the side edges of the cross member  21  of the cutting head. The edge of flanges  122  can engage the edge of the cross member  21 . 
     The shaft  104  of the center drill or pilot bit is centrally disposed in spaced apart alignment with the sidewalls of the cutting head. The shaft  104  of the center drill bit can be formed as a single cylindrical longitudinal member or as a longitudinal member including a plurality of tapered support plates  106  (two or three or four or more) extending from the base. The shaft can attach to a point or be welded all along the vertical edge to the shaft end converging at a point near the drill tip. The tapered ends of the support plates end in a short cylindrical collar  111  having a thicker bottom portion  113  of a larger diameter than the elongated top portion  115 . The distal end portion  115  can include a threaded bore  108  therein for cooperative engagement with a drill tip  110  having a complementary sized shaft  112 . A drill head  114  can include angled edges  116  and a pointed tip  118  for cutting into hard surfaces such as rock. 
     The pilot drill bit  100  is mounted within the cutting head of the auger wherein the elongated top portion of the collar extends outward pass the cutting head approximately equal with the tips of the cutting head teeth. The pointed tip  118  extends pass the cutting teeth for centering and holding the auger in position in order for the cutting teeth to anchor and cut a precision hole into the hard rock substrate. The pilot drill bit  100  also provides a means for setting the flightless auger onto a flat hard rock surface. The pilot drill bit  100  cuts a center hole in the surface anchoring the flightless auger so that the cutting teeth are pulled therein. The bit  100  can cut into the substrate forming a neat round hole in the desired location rather than skidding or walking around on the surface before the hole sidewalls are established. 
     The bottom of the support member connecting the side walls at the top of the cutting head can have a plurality of tapered support plates attaching to the bottom of the cutting head support plate. The base of the drill bit  100  extending opposite thereof is disposed concentrically within the cutting head. The cutting head can have cutaway portions forming opposing openings  120  in the top portion of the cutting head cylindrical body. The openings  120  can extend from the corners of the cutting head support plate for providing access to the bolts for removal of the cutting drill bit and removal of the rock substrate plug from the cutting head. 
     The embodiment of the flightless rock auger shown in FIGS. 16-21, include a portion “section” of the side wall being removed from the upper section. The portion may be of uniform dimensions cut from top to bottom or angled as shown. The preferred embodiment shown also includes a double wall wherein one of the walls forms an angled side edge along the longitudinal “lengthwise” dimension resulting in a side cutting edge; however, a single wall unit could have cutout portion formed with an angled sidewall edge as well. As best illustrated in FIG. 22, the unit can also be used with a pilot bit  110 . The opening formed in the upper section extends from one corner of the cross member  21  which supports the base of the pilot bit to the adjacent corner of the cross member  21 . The opposing sidewall could also be removed as long as the cutting head upper section retained sufficient structural strength so as not to buckle or collapse under a load. While the bottom section usually provides enough suction and compression to maintain a plug within the top section. The upper or top section cutout portion may be designed to maximize the opening depending upon the rock and/or clay substrate. Of course, suction is not a problem when the cutting head is removed from the hole and the large opening provides ample space and facilitates quick and efficient removal of the substrate from the cutting head. The cutting side edges also trim and cut substrate along the sides of the drilling head forming a clean hole having uniform smoother sidewalls. The lower section of the cutting head need not extend outwardly at a greater diameter than the upper section of the cutting head when the side edges are utilize. Moreover, the outwardly extending angle of the cutting teeth may be reduced or even eliminated when using the side cutting angle. The length or ratio of the upper and lower sections can also be customized for use in particular hard substrates. 
     Comparing the embodiment of FIG. 19 with that of FIG. 21, it can be seen that the embodiment can include a double wall formed of two concentric layers overlapping one another. The cutaway section may result in both layers being removed creating a single cutting edge or one layer can have a greater circumference than the other layer thereby forming a pair of overlapping cutting edges spaced apart from one another. The layers of the walls form an angled side edge along the longitudinal “lengthwise” dimension resulting in a side cutting edge or a thick double wall. Of course a single wall unit could have cutout portion formed with an angled sidewall edge as well. 
     The opening formed in the upper section extends from one corner of the cross member  21  which supports the base of the pilot bit to the adjacent corner of the cross member  21 . The opposing sidewall could also be removed forming a double opening as long as the cutting head upper section retained sufficient structural strength so as not to buckle or collapse under a load. While the bottom section usually provides enough suction and compression to maintain a plug within the top section. The upper or top section cutout portion may be designed to maximize the opening depending upon the rock and/or clay substrate. Of course, suction is not a problem when the cutting head is removed from the hole and the large opening provides ample space and facilitates quick and efficient removal of the substrate from the cutting head. The cutting side edges also trim and cut substrate along the sides of the drilling head forming a clean hole having uniform smoother sidewalls. The lower section of the cutting head need not extend outwardly at a greater diameter than the upper section of the cutting head when the side edges are utilize. Moreover, the outwardly extending angle of the cutting teeth may be reduced or even eliminated when using the side cutting angle. The length or ratio of the upper and lower sections can also be customized for use in particular hard substrates. 
     The embodiments shown in FIGS. 25-29, show the cylindrical body of the cutting head with and without a pilot bit, and with a portion of the side wall being removed from the cylindrical body portion of the cutting head. All of the embodiments utilize a short coupling mounted directly to the support member extending across the top of the cutting head. Reinforcement members may be bolted or welded to the sides of the coupling and the support plate as well. This embodiment is especially adaptable for use with pressure drilling rigs. 
     Finally it is contemplated that a number of smaller openings formed by holes, slots, or slits may be formed in the upper section of the drilling head as an alternate means to provide additional access to the substrate hole and provide drainage for water during the drilling process. 
     Method of Use 
     The method of using the flightless rock auger is as follows: The method of removing a plug of hard substrate from a posthole, using a flightless rock auger with a drilling rig, comprising the steps of: 
     a) Attaching the flightless rock auger to the drive shaft of a power unit of the drilling rig, the flightless rock auger comprising a cylindrical hollow cutting head comprising a hollow cylindrical body defining side walls connecting a top end defining an upper peripheral edge and a lower open end defining a lower peripheral cutting edge including a plurality of teeth extending from the lower peripheral edge, the top end of the hollow cylindrical body including at least one support member extending across at least a portion of the top end joining the side walls, a quick disconnect coupling mounting to the at least one support member for removable attachment to a drive shaft of a power unit; 
     b) lowering the flightless rock auger into a posthole containing a hard substrate; 
     c) placing the flightless rock auger onto the hard substrate; 
     d) rotating the flightless rock auger at a very low rpm at less than 20 rpm; 
     e) forming a plug of hard substrate inside of the cylindrical body of the flightless rock auger; 
     f) lifting the flightless rock auger and the plug from the posthole; and 
     g) removing the plug of the hard substrate out of the cylindrical hollow cutting head. 
     More particularly, a method of removing a plug of hard substrate from a posthole, using a flightless rock auger with a drilling rig, comprises the steps of: 
     a) attaching a flightless rock auger to the drive shaft of a power unit of the drilling rig, the flightless rock auger comprising a cylindrical hollow cutting head comprising a hollow cylindrical body defining side walls connecting a top end defining an upper peripheral edge and a lower open end defining a lower peripheral cutting edge including a plurality of teeth extending from the lower peripheral edge, the top end of the hollow cylindrical body including at least one support member extending across at least a portion of the top end joining the side walls, a means for connecting to a shaft comprising a quick connect coupling includes a proximal end connecting to the at least one support member and having an opposing distal end extending therefrom including means for removably connecting to a drive shaft of a power unit; 
     b) lowering the flightless rock auger into a posthole containing a hard substrate; 
     c) placing the flightless rock auger onto the hard substrate; 
     d) rotating the flightless rock auger at a very low rpm up to 20 revolutions per minute “rpm”; 
     e) forming a plug of hard substrate inside of the cylindrical body of the flightless rock auger; 
     f) lifting the flightless rock auger and the plug from the posthole; and 
     g) removing the plug of the hard substrate out of the cylindrical hollow cutting head. 
     The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art based upon more recent disclosures and may be made without departing from the spirit of the invention and scope of the appended claims.