US3794129A

US3794129A - Step auger and rock bit combination

Info

Publication number: US3794129A
Application number: US00311311A
Authority: US
Inventors: T Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-01
Filing date: 1972-12-01
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26
Also published as: FR2209039B1; ZA738875B; IT1001892B; FR2209039A1; CA992533A; GB1433556A; ES421061A1

Abstract

Combination earth drilling tool in the form of a step auger having a pilot bit attached thereto. A downwardly spiraling flight member is affixed to an elongated axial hub member with the leading edge of the flight terminating in a plurality of cutting teeth arranged in a novel pattern relative to one another and the flight. The cutting teeth are arranged radially from the hub and along the leading edge of the flight member in a configuration which causes the innermost of the digging teeth to cut a first step outwardly from the pilot hole while the remaining of the cutting teeth trail behind and cut subsequent steps into a formation. The pilot bit is in the form of a rotary rock bit having radially spaced apart pockets formed within a novel cylindrical member and a novel body portion so that the shank of a removable cutting tooth is received within the pocket with a portion of the shank extending outwardly of the pocket where the shank can be removably fastened to a shoulder formed between the body portion and the cylindrical portion. The pockets on both the flights and the rock bit are arranged into a configuration whereby any one of the cutting teeth can be substituted for any other one cutting tooth, thereby enabling a single type or designed cutting tooth to be utilized by both the auger and the bit.

Description

*ited States Patent [151 Taylor Feb. 26, 1974 1 STEP AUGER AND ROCK BIT COMBINATION [76] lnventor: Thomas L. Taylor, PO. Box 6048,

Odessa, Tex. 79760 [22] Filed: Dec. 1, 1972 I 21 Appl. No.: 311,311

[51] Int. Cl. E21c 13/04 [58] Field of Search 175/391, 412, 413, 394

[56] 1 References Cited UNlTED STATES PATENTS 3,422,915 1/1969 Watts 175/394 X 3,235,018 2/1966 Troeppl 175/413 X 2,594,261 4/1952 Henning 175/391 2,610,829 9/1952 Huckshold 175/412 X 2,701,126 2/1955 McClennan 175/391 2,731,237 l/l956 Henning 175/391 3,672,455 6/1972 Foster 175/412 Primary Examiner-Henry C. Sutherland Assistant ExaminerRichard E. Favreau Attorney, Agent, or Firm-Marcus L. Bates [57] ABSTRACT Combination earth drilling tool in the form of a step auger having a pilot bit attached thereto. A downwardly spiraling flight member is affixed to an elongated axial hub member with the leading edge of the flight terminating in a plurality of cutting teeth arranged in a novel pattern relativeto one another and r the flight. The cutting teeth are arranged radially from the hub and along the leading edge of the flight member in a configuration which causes the innermost of the digging teeth to cut a first step outwardly from the pilot hole while the remaining of the cutting teeth trail behind and cut subsequent steps into a formation.

' The pilot bit is in the form of a rotary rock bit having radially spaced apart pockets formed within a novel cylindrical member and a novel body portion so that the shank of a removable cutting tooth is received within the pocket with a portion of the shank extending outwardly of the pocket where the shank can be removably fastened to a shoulder formed between the body portion and the cylindrical portion.

The pockets on both the flights and the rock bit are arranged into a configuration whereby any one of the cutting teeth can be substituted for any other one cutting tooth, thereby enabling a single type or designed cutting tooth to be utilized by both the auger and the bit.

14 Claims, 17 Drawing Figures PAIENTEUFEBZB-IQH 3 79 4 129 SHEET 2 BF 3 FIG. 4

1 STEP AUGER AND ROCKBIT COMBINATION BACKGROUND OF THE INVENTION In forming bore holes in rock, gypsum, and the like with an auger, it is desirable 'to .provide the auger with a pilot bit so as to accelerate the speed of penetration through the formation. It is furthermore desirable to be able to replace the cutting teeth on both the auger and pilot bit with the replacement being effected in the field.

Another desirable attribute of an auger of the above described type is to realize maximum rate of penetration for the power provided by the prime mover. It is further desirable that the walls of the bore hole be maintained in a smooth condition soas to prevent irregularities and caving of material. Hence, the auger should have digging teeth of durable material with the teeth each being of a design and being disposed in a pattern that causes the power expended thereinto to cut away the maximum amount of formation for a minimum cost.

Another desirable attribute of augers of the above described type is that they be rugged in design, low in cost, and enjoy a long life so that a considerable length of time expires between major repairs.

SUMMARY OF THE INVENTION A heavy duty step-type rock auger in combination with a rotary rock bit wherein the step type auger comprises an axial hub member having a downwardly spiraling flight affixed thereto and terminating in a plurality of cutting teeth. The cutting teeth are individually housed within a special pocket with each pocket being aligned along a radius drawn from the central longitudinal axis of the hub, and with each adjacent pocket being arranged relative to one another,'so that the digging teeth are spaced both circumferentially and vertically. This configuration provides astep auger wherein the pilot bit, together with the cutting teeth which forms the leading edge of the flight, simultaneously cut a borehole having a bottom most surface in the form of a plurality of concentrically arranged cylinders which dimenish in diameter in a downward direction.

The rotary rock bit is attached to the lowermost end of the auger hub and includes a cylindrical member which enlarges into a body portion with vertically disposed pockets being formed therewithin. Each pocket extends through both the body portion and an outer marginal portion of the cylindrical member, thereby leaving a downwardly opening cavity within which the shank of a rock cutting or digging tooth is received. The shoulder formed between the cylindrical member and the body portion provides a surface against which a fastener means associated with the shank can bear to thereby maintain the cutting teeth affixed to the bit.

A primary object of this invention is the provision of improvements in a step type rock auger in combination witha rotary rock bit.

Another object of the invention is to provide a step type rock auger having pockets formed on the leading edge of the flight thereof, with the pockets being arranged vertically relative to the borehole and disposed along a radius drawn from the axial center line of the longitudinal central axis of the assembly, and with the pockets being spaced apart both vertically, angularly, and circumferentially from one another. Y

A further object of this invention is to provide an earth auger with removable cutting teeth wherein the teeth are arranged relative to one another so as to realize the maximum rate of penetration for a specific power requirement.

A still further object of this invention is to provide a combination augerand pilot bit having removable cutting teeth thereon which may be readily substituted one for the other.

Another and still further object is to provide improvements in a rotary rock cutting bit wherein a plurality of cutting teeth are captured to the bit in an improved manner.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims any by referring to the accompanying drawings.

The above objects are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as described in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a heavy duty step type rock auger having a rotary rock pilot bit attached to the lower end thereof, with some parts being cut away therefrom;

FIG. 2 is a broken, diagrammatical, bottom view of the auger disclosed in FIG. 1, with some parts being removed therefrom and other parts being broken away to conserve space;

FIG. 3 is a top plan view of the apparatus disclosed in FIG. 1;

FIG. 4 is an enlarged plan view of the bottom-side of part of the apparatus disclosed in the foregoing figures;

FIG. 5 is a part cross-sectional view taken along line 5--5 of FIG. 4, and further disclosing additional parts added thereto;

FIG. 6 is a top plan view of the apparatus disclosed in FIGS. 4 and 5;

FIG. 7 is a part diagrammatical, part schematical, fragmentary representation of the results of the use of the apparatus of FIG. 1 while penetrating a formation;

FIG. 8A is a reduced top plan view which discloses one of the steps involved during the fabrication of part of the apparatus used in FIG. 1;

FIG. 8B is a reduced side elevational view of part of the apparatus disclosed in FIG. 1;

FIG. 8C is a reduced hypothetical top plan view disclosing a constructional feature of part of the apparatus of FIG. 1;

FIG. 9 is an enlarged elevational view of the pilot bit disclosed in FIG. 1, with some parts being removed therefrom for simplicity;

FIG. 10 is a bottom view of the apparatus of FIG. 9 with some parts thereof being removed for clarity;

FIG. 11 is a top plan view of the apparatus disclosed in FIG. 9;

FIG. 12 is a fragmentary, part cross-sectional side view of FIG. 10, with some additional parts being included;

FIG. 13 is a fragmentary, part cross-sectional view, taken along line 13-13 of FIG. 9;

FIG. 14 is a fragmentary, part cross-sectional view, similar in some respects to FIG. 12, which discloses a cutting tooth which is used in conjunction with the present invention; and

FIG. 15 is an enlarged side view of a cutting tooth.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The arrow at 15 in FIG. 1 generally discloses a combination step type rock auger and rotary bit made in accordance with the present invention. The auger includes a longitudinally extending tubular-like structure 16 which is in the form of a square hub portion 17 having a chuck 18 at the upper extremity thereof for connection to a prime mover (not shown) in a manner which is known to those skilled in the art.

The square hub telescopingly receives a cylindrical drill shaft 19 therein with the lower terminal end 20 of the shaft threadily receiving a pilot bit 21 therein. The hub and shaft may be one intergral part, if desired. A flight in the form of a spiral web, having an outermost diameter 22, is affixed to the hub and to the shaft to present a trailing edge 23 and a leading edge 24.

The leading edge of the flight is provided with or formed into a plurality of cutting teeth 25. The teeth individually are removably received within a pocket 26 in one of several manners known to those skilled in the art, and specifically as will be taught later on in this disclosure.

A dummy web, generally indicated by the arrow at numeral 27, is symmetrically arranged relative to the flight in the illustrated manner of FIG. 1. The dummy web is provided with pockets and teeth in the before described manner. While a dummy web is illustrated herein, it should be understood that this invention comprehends the fabrication of apparatus devoid of such a web.

Looking now to the part schematical, part diagrammatical illustration of FIG. 2, it will be seen that the pockets 26 are arranged in a particular novel configuration, with any one pocket of the flight beng diametrically opposed to the similarly positioned or corresponding pocket located on the dummy web. The

innermost pockets

26 and 126 are preferably attached to both the shaft and to the leading edge of the flight. Each opposed pocket is arranged with their longitudinally extending axis coinciding with a radial line drawn through the longitudinal central axis of the drill shaft. This relative disposition of the pocket is hereinafter referred to as the radial longitudinal axis" of the pocket. Outermost pocket 226 is spaced circumferentially from the innermost pocket and spaced vertically above the innermost pocket an amount determined by the pitch of the flight. The intermediate pockets 26' are progressively spaced apart from one another both circumferentially and vertically so that the resultant profile of the teeth will engage a formation in an overlapping manner. Numeral 31 indicates the vertical distance each pocket, or adjacent cutting tooth, is spaced apart from one another.

As seen illustrated in FIGS. 4, 5, and 6, each pocket is provided with a tapered slot 28 which receives a complimentary tapered tang 29 of the cutting teeth in a wedge-like manner, with the rear face orabuttment mean 45 of the cutting tooth being abuttingly received by the illustrated load carrying member 30.

As an example of the specific details of an l8 inch diameter auger made in accordance with this invention, the flight preferably is fabricated from one-half inch plate, with the plate being apertured as seen at 19', and provided with a out along the radius thereof, thereby providing adjacent end portions 23', 24'. The end portions are pried apart vertically by placing the plate member in a hydraulic press and mold, thereby forming a portion of the length of the flight illustrated in FIG. 1. As seen illustrated in FIG. 8C, the plate portion forming the lowermost portion of the flight is provided with a plurality of cutouts with each of the cutouts being placed so that when one of the beforementioned pockets are welded therein, the resultant pocket will lie with the radial longitudinal axis thereof disposed in the before recited manner, and in a position to dispose the cutting edge portion of the teeth received therein normal to a circle described during one revolution of the auger shaft.

In a 24 inch OD auger having a 5 inch OD shaft, and usingj pock ets 2 /2 inches in length, each of the five pockets were arranged adjacent to one another in the manner illustrated by the three innermost pockets of FIG. 2. The radial spacing 231 of the pockets was maintained at 1% inches. This configuration provided a flight having a strong leading edge since each pocket is welded to the flight and to an adjacent pocket. It will be noted that this configuration disposed the teeth or pockets circumferentially about the flight an amount less than Looking now to the details of FIGS. 9-15, the pilot bit generally illustrated at arrow 21 is provided with the usual threaded pin end 32, which can take on any one of several known forms. Shoulder 34 is formed between cylindrical member 33 and the threaded coupling an amount consistent with the design of the drill shaft. The lower body portion is in the form of an enlargement having three equally spaced apart radially outwardly extending portions 35. The lower body portion is stepped-off from the cylindrical member by the provision of the illustrated shoulder 36, which preferably is planar in form, although it could take on other configurations while remaining within the scope of this invention.

The lower face 37 of the bit is also planar in form, and preferably includes a maximum OD which terminates at the outermost edge portion of the load carrying member 38. The load carrying member is defined by

edge portions

39, 40, 41, and includes a lowermost face 42.

As best seen in the illustration of FIGS. 10 and 11, the body portion includes three radially extending enlargements having a trailing edge 40 and a leading edge 43 which form adequate structure within which a pocket 44 is formed. The pocket downwardly opens with the entrance thereto being defined by lower face 37 of the bit. The tapered pocket extends through the body portion enlargements and into a major portion of the cylindrical member, with the pocket having a portion thereof upwardly opening through shoulder 36 and another portion thereof outwardly opening from the outer periphery of the side wall of the cylindrical member 33.

Edge portion 46 of the cylindrical member defines the length of the roof 47 of the pocket, thereby leaving wall surface 48 of the cylindrical member for transfering loads into the threaded pin end 32. Spaced apart diametrically opposed walls 49, 50of the pocket are arranged so that an upper portion of the tang of the beforementioned cutting teeth can freely extend outwardly of the cylindrical body portion of the bit in the area generally illustrated by the arrow at numeral 51, and as best seen in the illustration of FIGS. 9, 12 and 14 (in conjunction with FIG. 13).

Those skilled in the art will now appreciate that the pockets of the drill bit are of a configuration to enable the cutting teeth used in conjunction with the auger of FIG. 1 to also be used in conjunction with the rotary rock bit of FIG. 9, thereby bringing about the advantage of being able to maintain an inventory of a single type cutting tooth in order to supply the demands of both the auger and the bit.

It will further be noted that the pockets of the bit are arranged spaced from one another and to the axial center line of the bit, with the innermost edge portion of the pocket lying adjacent to a line drawn radially from the axial center line of the bit.

The apparatus, while penetrating a formation, removes material therefrom in a step like manner, with the pilot bit providing the first penetration at 121 of FIG. 7, and with the innermost cutting tooth of the auger forming the lowermost and innermost step cut 125, and with the outermost and uppermost cutting tooth forming the last cut 225, to thereby form a borehole having a diameter 222. The number of intermediate steps, or cuts, provided by a corresponding number of cutting teeth, will depend upon the pitch and OD of the flight. Preferably, three or more cutting teeth will be employed with the teeth being spaced radially apart an amount 231, and vertically an amount as seen at 31, depending upon the number and configuration of the teeth employed.

The cutting teeth of the apparatus are individually inserted into a pocket by carefully striking the butt end 45 opposite the carbide cutting tip 25' so as to drive the wedge shaped tang into the corresponding and complementary wedge shaped pocket, with the butt end being forced against the

load carrying member

30 or 42. The tang is provided with a keeper, such as a cotter pin, to prevent loss of the tooth should it inadvertently become unwedged from its pocket. The tang can be provided with dual apertures if desired, the central aperture being for use in conjunction with the auger pocket and the off-set aperture being for use in conjunction with the rotary bit. A single off-set aperture will suffice for both applications, if desired.

1 claim:

1. Earth drilling tool comprising an auger in combination with a pilot bit; saidauger comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in a pilot bit at the lower end;

a flight affixed to and radiating from said hub, with said flight having an upper end which terminates adjacent said chuck and a lower end which terminates adjacent said pilot bit;

said lower end of said flight having a plurality of cutting teeth thereon; said cutting teeth having a radial and a circumferential dimension, with said radial dimension being disposed along a radius of said hub and said circumferential dimension being disposed normal to said radius;

a first of said cutting teeth arranged adjacent to said hub, a last of said cutting teeth arranged adjacent to the outer periphery'of said flight, the remaining cutting teeth being arranged at different radii relative to each other and said first and last cutting teeth; each of said cutting teeth being arranged at different vertical elevations along said flight;

said pilot bit includes a plurality of cutting teeth arranged thereon; means by which the last said cutting teeth may be substituted for the first said cutting teeth whereby similar cutting teeth may arbitrarily be used in the flight and in the bit.

2. The tool of claim 1 and further including a pocket for each of said cutting teeth, said pockets being formed into the leading edge of said flight, said cutting teeth having a shank, said shank adapted to be removably received within said pocket.

3. The tool of claim 2 wherein said flight is fabricated from a disk having a central aperture and a radial cut extending from said aperture to the outer peripheral edge thereof to form a leading edge and a trailing edge, said edges being forced apart thereby forming a portion of said flight;

said leading edge having cutouts formed therein with said cutouts having a mean radial centerline lying along a radius drawn from said hub; said cutout having a width lying tangentially with respect to a circle drawn about said hub; and a pocket affixed to each said cutout; one of said teeth removably received within said pocket.

4. Earth drilling tool comprising an auger in combination with a pilot bit; said auger comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in a pilot bit at the lower end; i

said lower end of said flight having a plurality of cutting teeth thereon; said cutting teeth having a radial anda circumferential dimension, with said radial dimension being disposed along a radius of said hub and said circumferential dimension being disposed normal to said radius;

a first of said cutting teeth arranged adjacent to said hub, a last of said cutting teeth arranged adjacent to the outer periphery of said flight, the remaining cutting teeth being arranged at different radii relative to each other and said first and last cutting teeth; each of said cutting teeth being arranged at different vertical elevations along said flight;

said flight is fabricated in the form of a disk having a central aperture and a radial cut extending from said aperture to the outer peripheral edge thereof to form a leading edge and a trailing edge, with said edges being forced apart thereby forminga portion of said flight;

said leading edge having cutouts formed therein with said cutouts having a mean radial centerline lying along a radius drawn from said hub; said cutouts having a width lying tangential with respect to a circle drawn about said hub; and a pocket affixed to each said cutout; one of said teeth removably received within said pocket.

5. The tool of claim 4 wherein said pilot bit includes 1 a plurality of cutting teeth arranged thereon; means by which the last said cutting teeth may be substituted for the first said cutting teeth whereby similar cutting teeth may arbitrarily be used in the flight and in the bit.

6. The improvement of claim 4 wherein said bit is a rotaryrock bit comprising a body, a cylindrical member having attachment means at the upper end thereof for attachment to an auger, and a body portion at the lower end thereof, said body portion extending outward from said cylindrical member with a shoulder being formed therebetween; a plurality of downwardly opening pockets extending through said body portion and into said cylindrical member, said pocket portion contained within said cylindrical member having an outwardly opening aperture said pocket portion contained within said body portion having an upwardly opening portion through said shoulder;

cutting teeth, each having a cutting edge and a tang,

said tang being of a size and configuration to enable it to be received within said pocket with a portion of said tang freely extending above said shoulder and outwardly of said cylindrical member; whereby:

a fastener means affixed to said tang at said portion which extends above said shoulder enables one of said cutting teeth to be removably affixed to said body.

7. A rotary rock bit for use in an earth drilling tool comprising, a cylindrical member having attachment means at the upper end thereof for attachment to an auger, and a body portion at the lower end thereof, said body portion extending outwardly from said cylindrical member with a shoulder being formed therebetween; a plurality of downwardly opening pockets extending through said body portion and into said cylindrical member, said pocket portion contained within said cylindrical member having an outwardly opening pocket portion, said pocket portion contained within said body portion having an upwardly opening portion through said shoulder;

cutting teeth, each having a cutting edge and a tang,

said tang being of a size and configuration to be received within said pocket with a portion of said tang freely extending above said shoulder and outwardly of said cylindrical member; whereby:

8. The rotary rock bit of claim 7 wherein the pockets are tapered and said tangs are similarly tapered so that the cutting teeth are firmly received within the pockets.

9. The rotary rock bit of claim 7 wherein said pockets of the bit are arranged spaced from one another and to the axial centerline of the bit, with an innermost edge portion of the pocket lying adjacent to a line drawn radially from the axial centerline of the bit.

10. The rotary rock bit of claim 7 wherein said cutting teeth include an abutment located rearwardly of said cutting edge, said body portion includes radially spaced pocket forming elements, each element having a leading edge portion and a trailing edge portion; a load carrying member formed on said trailing edge portion adapted to abuttingly engage said abutment on said cutting teeth;

6 said pockets being elongated slots radially disposed 5 relative to the longitudinal axis of the bit and laterally disposed to the circumference of the bit.

11. The rotary rock bit of claim 10 wherein said cutting teeth comprise a shoulder between said tang and said cutting edge;

said shoulder being received in abutting relationship against a planiform face of said bit body.

12. Earth drilling tool comprising an auger in combination with a pilot bit; said auger comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in a pilot bit at the lower end;

said bit is a rotary rock bit comprising a body, a cylindrical member having attachment means at the upper end thereof for attachment to an auger, and a body portion at the lower end thereof, said body portion extending outward from said cylindrical member with a shoulder being formed therebetween; a plurality of downwardly opening pockets extending through said body portion and into said cylindrical member, said pocket portion contained within said cylindrical member having an outwardly opening aperture, said pocket portion contained within said body portion having an upwardly opening portion through said shoulder;

cutting teeth, each having a cutting edge and a tang,

said tang being of a size and configuration to enable it to be received within said pocket with a portion of said tang freely extending above said shoulder and outwardly of said cylindrical member, whereby:

13. Earth drilling tool comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in an earth engaging member at the lower end thereof;

a flight affixed to and radiating from said hub; said flight being in the form of a spiral having means forming a central aperture through which said hub member is received, and spaced radial edge portions extending from the aperture to the outer peripheral edge of the flight to form a leading edge and a trailing edge with said leading and trailing edges being spaced apart by the central portion of the flight;

said leading edge having cutouts formed therein, said cutouts being radially, vertically, and circumferentially' spaced from one another; a pocket affixed to each said cutout; a cutting tooth removably received within each pocket;

each cutting tooth having a radial and a circumferem tial dimension, with said radial dimension being disposed along a radius drawn from said hub and said circumferential dimension being disposed normal to said radius;

a first said cutting tooth arranged adjacent to said hub; a last said cutting tooth arranged adjacent to the outer periphery of said flight, a remaining cutting tooth being arranged at different radii relative to said first and last cutting tooth; each of said cutting teeth being arranged at different vertical elevations along said flight; so that the cutting edge of the teeth are arranged with a cutting edge thereof lying along a radius drawn from said hub, and with the teeth having a width lying tangential with respect to a circle drawn about said hub.

14. The tool of claim 13 and further including a pilot bit affixed to said earth engaging member, said pilot bit includes a plurality of cutting teeth arranged thereon; means by which the last said cutting teeth may be substituted for the first said cutting teeth whereby similar cutting teeth may arbitrarily be used in the flight and in the bit.

Claims

1. Earth drilling tool comprising an auger in combination with a pilot bit; said auger comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in a pilot bit at the lower end; a flight affixed to and radiating from said hub, with said flight having an upper end which terminates adjacent said chuck and a lower end which terminates adjacent said pilot bit; said lower end of said flight having a plurality of cutting teeth thereon; said cutting teeth having a radial and a circumferential dimension, with said radial dimension being disposed along a radius of said hub and said circumferential dimension being disposed normal to said radius; a first of said cutting teeth arranged adjacent to said hub, a last of said cutting teeth arranged adjacent to the outer periphery of said flight, the remaining cutting teeth being arranged at different radii relative to each other and said first and last cutting teeth; each of said cutting teeth being arranged at different vertical elevations along said flight; said pilot bit includes a plurality of cutting teeth arranged thereon; means by which the last said cutting teeth may be substituted for the first said cutting teeth whereby similar cutting teeth may arbitrarily be used in the flight and in the bit.

3. The tool of claim 2 wherein said flight is fabricated from a disk having a central aperture and a radial cut extending from said aperture to the outer peripheral edge thereof to form a leading edge and a trailing edge, said edges being forced apart thereby forming a portion of said flight; said leading edge having cutouts formed therein with said cutouts having a mean radial centerline lying along a radius drawn from said hub; said cutout having a width lying tangentially with respect to a circle drawn about said hub; and a pocket affixed to each said cutout; one of said teeth removably received within said pocket.

4. Earth drilling tool comprising an auger in combination with a pilot bit; said auger comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in a pilot bit at the lower end; a flight affixed to and radiating from said hub, with said flight having an upper end which terminates adjacent said chuck and a lower end which terminates adjacent said pilot bit; said lower end of saId flight having a plurality of cutting teeth thereon; said cutting teeth having a radial and a circumferential dimension, with said radial dimension being disposed along a radius of said hub and said circumferential dimension being disposed normal to said radius; a first of said cutting teeth arranged adjacent to said hub, a last of said cutting teeth arranged adjacent to the outer periphery of said flight, the remaining cutting teeth being arranged at different radii relative to each other and said first and last cutting teeth; each of said cutting teeth being arranged at different vertical elevations along said flight; said flight is fabricated in the form of a disk having a central aperture and a radial cut extending from said aperture to the outer peripheral edge thereof to form a leading edge and a trailing edge, with said edges being forced apart thereby forming a portion of said flight; said leading edge having cutouts formed therein with said cutouts having a mean radial centerline lying along a radius drawn from said hub; said cutouts having a width lying tangential with respect to a circle drawn about said hub; and a pocket affixed to each said cutout; one of said teeth removably received within said pocket.

5. The tool of claim 4 wherein said pilot bit includes a plurality of cutting teeth arranged thereon; means by which the last said cutting teeth may be substituted for the first said cutting teeth whereby similar cutting teeth may arbitrarily be used in the flight and in the bit.

6. The improvement of claim 4 wherein said bit is a rotary rock bit comprising a body, a cylindrical member having attachment means at the upper end thereof for attachment to an auger, and a body portion at the lower end thereof, said body portion extending outward from said cylindrical member with a shoulder being formed therebetween; a plurality of downwardly opening pockets extending through said body portion and into said cylindrical member, said pocket portion contained within said cylindrical member having an outwardly opening aperture said pocket portion contained within said body portion having an upwardly opening portion through said shoulder; cutting teeth, each having a cutting edge and a tang, said tang being of a size and configuration to enable it to be received within said pocket with a portion of said tang freely extending above said shoulder and outwardly of said cylindrical member; whereby: a fastener means affixed to said tang at said portion which extends above said shoulder enables one of said cutting teeth to be removably affixed to said body.

7. A rotary rock bit for use in an earth drilling tool comprising, a cylindrical member having attachment means at the upper end thereof for attachment to an auger, and a body portion at the lower end thereof, said body portion extending outwardly from said cylindrical member with a shoulder being formed therebetween; a plurality of downwardly opening pockets extending through said body portion and into said cylindrical member, said pocket portion contained within said cylindrical member having an outwardly opening pocket portion, said pocket portion contained within said body portion having an upwardly opening portion through said shoulder; cutting teeth, each having a cutting edge and a tang, said tang being of a size and configuration to be received within said pocket with a portion of said tang freely extending above said shoulder and outwardly of said cylindrical member; whereby: a fastener means affixed to said tang at said portion which extends above said shoulder enables one of said cutting teeth to be removably affixed to said body.

10. The rotary rock bit of claim 7 wherein said cutting teeth include an abutment located rearwardly of said cutting edge, said body portion includes radially spaced pocket forming elements, each element having a leading edge portion and a trailing edge portion; a load carrying member formed on said trailing edge portion adapted to abuttingly engage said abutment on said cutting teeth; said pockets being elongated slots radially disposed relative to the longitudinal axis of the bit and laterally disposed to the circumference of the bit.

11. The rotary rock bit of claim 10 wherein said cutting teeth comprise a shoulder between said tang and said cutting edge; said shoulder being received in abutting relationship against a planiform face of said bit body.

12. Earth drilling tool comprising an auger in combination with a pilot bit; said auger comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in a pilot bit at the lower end; a flight affixed to and radiating from said hub, with said flight having an upper end which terminates adjacent said chuck and a lower end which terminates adjacent said pilot bit; said lower end of said flight having a plurality of cutting teeth thereon; said cutting teeth having a radial and a circumferential dimension, with said radial dimension being disposed along a radius of said hub and said circumferential dimension being disposed normal to said radius; a first of said cutting teeth arranged adjacent to said hub, a last of said cutting teeth arranged adjacent to the outer periphery of said flight, the remaining cutting teeth being arranged at different radii relative to each other and said first and last cutting teeth; each of said cutting teeth being arranged at different vertical elevations along said flight; said bit is a rotary rock bit comprising a body, a cylindrical member having attachment means at the upper end thereof for attachment to an auger, and a body portion at the lower end thereof, said body portion extending outward from said cylindrical member with a shoulder being formed therebetween; a plurality of downwardly opening pockets extending through said body portion and into said cylindrical member, said pocket portion contained within said cylindrical member having an outwardly opening aperture, said pocket portion contained within said body portion having an upwardly opening portion through said shoulder; cutting teeth, each having a cutting edge and a tang, said tang being of a size and configuration to enable it to be received within said pocket with a portion of said tang freely extending above said shoulder and outwardly of said cylindrical member, whereby: a fastener means affixed to said tang at said portion which extends above said shoulder enables one of said cutting teeth to be removably affixed to said body.

13. Earth drilling tool comprising an elongated axial hub member terminating in a chuck at the upper end and terminating in an earth engaging member at the lower end thereof; a flight affixed to and radiating from said hub; said flight being in the form of a spiral having means forming a central aperture through which said hub member is received, and spaced radial edge portions extending from the aperture to the outer peripheral edge of the flight to form a leading edge and a trailing edge with said leading and trailing edges being spaced apart by the central portion of the flight; said leading edge having cutouts formed therein, said cutouts being radially, vertically, and circumferentially spaced from one another; a pocket affixed to each said cutout; a cutting tooth removably received within each pocket; each cutting tooth having a radial and a circumferential dimension, with said radial dimension being disposed along a radius drawn from said hub and said circumferential dimension being disposed normal to said radius; A first said cutting tooth arranged adjacent to said hub; a last said cutting tooth arranged adjacent to the outer periphery of said flight, a remaining cutting tooth being arranged at different radii relative to said first and last cutting tooth; each of said cutting teeth being arranged at different vertical elevations along said flight; so that the cutting edge of the teeth are arranged with a cutting edge thereof lying along a radius drawn from said hub, and with the teeth having a width lying tangential with respect to a circle drawn about said hub.