US2086751A - Earth boring bit - Google Patents

Description

AJuly 13, 1937.v E. L'. TAYLOR EARTH BORING BIT 5 Sheets-Sheet l Filed Dec, 19, 1934 July 13, 1937.

3 Sheets-Sheet 3 m 5. w w m w .L u wa E Q b a L m u 7. @I w w 5 w f .1-- y NJ um l /ji f' 145 JZO Patented July 13, 1937 2,086,751 EARTH BORING Brr Edward L. Taylor, Long Beach, Calif.

Application December 19, 1934, Serial No. 758,252 (o1. 25a-71) 14 (Hanns.

My invention relates to a combination type of reamer rock and drag rotary drill bitin which,

when used as a rock drill, the cutters are of a rotating cutter type in which a row of rotary cutters mounted on a transverse shaft extend across one diameterof the bit and at the marginal ends of the other diameter there are opposed pairs of sets of rotary cutters these being slightly inclined with their axes tilted downwardly and inwardly. When the drill is used as a drag bit the set of transverse rotary cutters 4are removed and a drag bit construction substituted. For cutting completely across the formation from side to side at the bottom of the hole these cutters are provided with a plurality of cutting teeth. y

In the above type of drill bit an object and feature of my invention is a construction by which the same shank may be used for a mounting of the rock bits having the rotary cutters or alternatively, for the drag bit having the drag cutters and cutting teeth'. By the shank `I mean the heavy central part of the drilling bit, this having a head and preferably a pin at the upper end which pin may be threaded in the box of a tool joint coupling or other connection, to the rotary drill pipe.

A further feature .of my invention is constructing the shank substantially square in cross section as to its upp'er'periphery and this being of the same cross section from the top to the bottom.y

Qn each face of the shank, removable tool carrying blocks are attached by bolts, or the like, such bolts extending through the shank from side to side. One pair of diametrically opposite blocks forms at its lower end the end bearings for the transverse shaft carrying the rotary discv cutters. There is also a central bearing block which is attached to the lower end of the shank; such shank havingpreferablya substantially plane lower end. The central bearing block is bolted to the end of the shank. u

A detailed feature of myinvention thus relates to the assembly of the tool supporting blocks attached to the` four vertical faces of the shank,

two opposite tool blocks at their ends forming a mounting for a transverse row of rotary cutting disks mounted on a diametrical shaft. The other two tool blocks only have rotary cutters on their lower ends, each having a stub shaft mounted at its center in a web on the 'tool block extending below the bottom of the shank, such stub shaft having rotating cutter disks thereon located outside and inside of the web'.

C Another object and feature of my invention in the substitution of the drag bit is in employing a construction having two tool blocks which may be substituted for the tool vblocks having the cutting discs mounted thereon. l These substitute blocks are bolted on Vtwo opposite faces of the shank by bolts extending through the blocks and thro-ugh the shank, and at the bottom of each substitute tool blockthere is formed integral' therewith a transverse drag bit cutter, the two cutters extending transversely across the tool in a diametrical manner. A detailed feature of the drag bits is that diametrically opposite on the extreme outside edge at the bottom I provide removable end cutters which cut the extreme outside .`of the hole bottom and have a vertical cutting .edge for the side wall. These removable marginal cutters are each tted in a socket in one of the drag bit sections or cutters.

A further detailed feature is in the employment of cutting teeth insertable in sockets formed in the lower face of each drag cutter. Therefore, broadly it may be stated that one of the main objects of my invention is in the construction of the rotary drill bit in whichl side blocks may be attached to or removed from the shank and these form the supports for rotating disk cut ers or have xed drag cutters. Another object and feature of my invention is in the provision for expansion and contraction of the drill bit to cut down sizes of holes.

Therefore, another main object and feature of my invention is in employing attaching keys in the form of shims interconnecting the lateral tool blocks to the central shank, these keys or shims being in different sizes or thicknesses so that by the use of substitute keys the diameter of,Y

the drill as a whole may be increased from its minimum size. In this construction of the shims I provide vertical undercut grooves in each face of the square -sectioned drill shank and in each of the tool blocks I likewiseprovide a complementary undercut groove. The keys are made in corresponding manner with projecting tongues, the shims with the tongues may -be assembled on the shaft and the tool blocks on the shims by a longitudinal sliding movement and then the assemblies tilted through the shank.

To accommodate the expansion for the rock drill having the rotary cutters a plurality of shims may be inserted on the main cutter disk shaft, this shaft being preferably formed in a plurality of sections,` each having its end connected to a stub shaft on the central bearing. The .expanding feature, in regard to the drag bit, also accommodates anv overlap of the drag bit cutters when in the contracted position and outward movement of these when the larger key shims are used.

. the accompanying drawings, in which: 1

Fig. 1 is a side elevation taken in the direction of the arrow I of Fig. 3 illustrating the bit arranged as a rock drill with rotary cutters and in its contracted or smallest cutting diameter.

Fig. 2 is a similar elevation to Fig. l but with the bit expanded to a larger diameter by using insert key shims to space the tool supporting lblocks from the shank.

Fig. 3 is a horizontal section on the line 3 3 of Fig. 1 in the direction of the arrows illustrating the use of keys between the shank and the tool blocks.

Fig. 4 is a horizontal section on the line 4 4 of Fig. 2 taken in the direction of the arrows il' lustrating key lshims spacing the tool blocks from the shank.

Fig. 5 is a vertical transverse section on the line 5 5 of Fig.\2 in the direction of the arrows showing in particular the transverse rotary cutters.

Fig. 6 is a side elevation taken in the direction of the arrow 6 of Fig. 7 showing the bit expanded and with a drag cutter substituted for the transverse rotary cutters.

Fig. 7 is an end view of Fig. 6 taken in the di- `rection of the arrow 1.

Fig. 8 is a view similar to Fig. -7 with the key shims removed and showing the tool reduced to its smallest cutting diameter. a

Fig. 9 is a detail vertical section on the line I 9 9 of Fig. 5 in the direction of the arrows.

Dealing rst with the construction of Figs. 1 through 5, the main body or shank bit designated by the numeral II has an elongated shank section I2 which is square'in cross lsection having equal flat side faces I3, which, when the tool is operating are each in a vertical plane. At the upper end of this main shank there is a cylindrical head I4 and a taper threaded pin I5,

the pin being adapted to threadinto a box of a tool joint coupling or the equivalent. The lower end of the shank preferably has a plane horizontal surface I6 (note Figs. 2 and v5). Each vertical face of the shank is provided with 'an' undercut groove I1, such groove having a vertical surface I6 with parallel marginal guide shoulders- I9 thus forming the undercut portion 20 of the grooves. These are all of similar construction on the four faces of the square portion of the` shank. ,l

The tool holding blocks25 are all of the same 'general typehaving vertical plane inner faces 26 to register with the vertical facesof the square section of the shank and each of these has an undercut groove 21 having a vertical base surface 28. The vertical grooves in the shank Vand* in thetool blocks are preferably similar so that,

keys 30 may be utilized and t in the grooves.

rthe. keys being inserted longitudinally from the bottom.` (Note Fig. 3.) Each key has two marginal tongues 3I on each vertical edge supported by a groove 32. The keys are provided with perforations 33 at spaced intervals. The tool blocks also haveperforations 34 at similar spacing and the square section ofthe shank -is also provided with transverse perforations 35.

center of the tool blocks. Two of the tool blocks at the bottom are provided with outwardly flared webs 45 (note-Figs. 1 and 2), such'webs extending below the bottom I6 of the square shank section. Mounted in the center of each of these webs there is a stub shaft 46, which shaft carries cutter discs' 41 on its outer end and a series of toothed cutter discs 46 on 4the inner end of the stub shaft. Such stub shaft is provided with an Y enlarged head 49 at one end and afwasher 50 at the opposite end is held in place by a rivet 5I through shaft 46, the rivet heads engaging the shaft head 49 and washer 50, thus attaching the `rotary cutters to the stub shaft 46 and retaining the cutters on such shaft. It will therefore be seen, referring to Figs. 1 and 2, that th'e stub shafts 46 are-downwardly and inwardly inclined toward the axial center of the bit. The cutters 41 preferably have annular cutting edges 52V separatedl by grooves 53 and the cutters 48 preferably have a series of teeth 54, such teeth extending longitudinally of the stub shaft 46. It will be noted, referring to the illustrations of Figs. 1 and 2, that one bolt is used at the upper portion of each of the tool blocks and two bolts adjacent the lower end of each pair. Therefore, a short recess is sufficient at the top and a long recess at the bottom to accommodate the bolt heads and nuts.

The other pair of tool blocks are fastened to the two remaining diametrically opposed faces of the square section of the shank,l the manner of attachmentA being the same 'as above described. These blocks, however, have a downwardly extending web 55 which is' parallel to the plane of the vertical face of the square shank section. (Note Fig. 5.) These form outer supports for a diametrical' cutter shaft 56. There is also provided a central bearing block 51, the lower portion 51 being a `cylinder joined to a block 58 which is seated in a shallow recess 56 in the lower surface. I6 of the square shank section preferably offset slightly from the center. This central block is secured in place by bolts 60 through the box. The opposite vsides of the -center block 51 have recesses 6| leaving a central commodate a nseries of lling' washers 66 when the tool is expanded.

On the shaft 56 outside of the webs 55 there is a series of rotary cutters 61, these shown being 69 with teeth parallel to the shaft and an outer a, disc 66 with a sharp peripheral edge, and discs disc 10 withA large teeth 1I. Each of the cutters 75 18 has la screw threaded socket 12 andl a shallow -recess 13 in which there is a threaded plug 14 engaging the threads of the recess 12 and having a head 15 fitting in the shallow recess 13. A locking rivet 16 extends through perforations in the plug 14 and shaft side 64, 63 and fin 62. The cutters of such shaft section between the webs 55 are preferably formed alternately of disc cutters similar to 68 having the sharp peripheral edge and cutters similar to 69 having teeth, but it is manifest that any suitable type of intermediate cutters may be used. The shaft 56 formed of the screw threaded fixed portion 63 and the outer fixed portion 64 do not rotate but the cutters' turn on such shaft.

In order to provide for the circulation of the y slushing mud there is a central axial duct 88 extending from the pin I5 through a head |4 and l a square section of a shank. This isl of suieach of the corners of the square section of the shank and occupy the four corners formed by the four tool blocks.' These pipes are inwardly bent at the top 83'(note Figs. 1 and 6), and connect to ducts 84 leading from the large opening 85 in the head and pin. These pipes have their discharge outlet 86 spaced slightly above the lower end I6 of the shank.

When it is desired to enlarge the drill bit for drilling an increased diameter hole, the bolts vattaching the tool blocks are removed, ,Y then the keys 38 are alsogrem'oved by a longitudinal movement, it being irst necessary to disconnect the -shaft sections 64 from the fixed shaft 63 (note Fig. 5) and thus disassemble the transverse rotary cutters. This allows a complete disassembling of the tool blocks from the square portion' of the shank. Then, the shim keys 98 may be substituted for the keys 38. Such keys are illustrated in cross section in Fig. 4 and have a central shim portion 9|, this having parallel opposite faces 92 and parallel side edges 9 3 except on the faces 92 key elements are formed. These have marginal tongues 95 with undercut grooves 96 and are designed to fit in the undercut grooves formed in the vertical side faces of the square section of the shank and also forming the inside vertical faces of the tool blocks 25. These shim keys 98 have perforations to accommodate the clamping bolts and when assembled, the bolts pass through the tool blocks, the shim keys 98 and theVVV central squared section of the shank thus securely attaching the tool blocks to the side faces of the shank. i

In Fig. 6 this vertical section shows the lower portionof a pair of shim keys 98 which may have n a slight downwardly extending corner 91 engaging the webs 55. These blocks also have cut-off f corners 98 to form a continuation of the slushing duct 8|. It is also necessary to have cut-off corners in the keys 38 to accommodate the iiow of the slushing mud through the ducts 8|.

It is manifest that different sizes of key shims 98 may be'used when it is desired to enlarge the drilling diameter from the contracted size as shown in crosssection in Fig. 3 having the narrow keys 38. On account of the shaft sections 64 being threaded on the xed shaft section 63 of the central block 51, accommodation may be made for-enlarging the diameter of the tool and a suitable number of cutters may be used on this shaft to' accommodate the shaft either when shortened or elongated, and, manifestly, the desired numberv of filling washers 66 may be utilized. p ,y

It will thus begseen thatthe bit is readily adapted for alteration to drill diameters of a`- hole using the rotary type of rock cutters.

When it is desired to utilize the drag bit construction of Figs. 6, '1, and 8 I proceed as follows:

In this case the diametrically opposite tool holders |88 having the flared web 45 are the same as used in the prior described construction employing the rock bit, and in fact, the same tool blocks may be used in both cases on these two faces of the squared shank. When the tool is contracted as shown im Fig. 8 I utilize the same type of keys 38 and these may be of the same size, and when the tool is expanded as illustrated in Fig. 7 I utilize the substitute key shims 98. When the device is expanded to a sufficient diameter I may use the cutter assembly on the stub shafts 46 having the various cutters 41 and 48 but where the tool is contracted as in Fig. 8 or only narrow shim keysare employed it is necessary to omit the inside cutters 48, in which case, for the stub shafts 46 I substitute a shorter stub shaft |8|. 49 andis secured in place by a cotter pin |82, or the like. Thus the stub shaft |8| may be held in any suitable manner in its supporting web 45 and carries the outside cutters 41 which may be of any suitable type. The two other tool blocks |83 aresubtsituted for the tool blocks of Figs. l through 4 having the web 55 at the bottom which carries the transverse rotary rock cutters. However, the upper portion of these blocks may be of the same type as the blocks formerly used so that when the device is in its contracted structure the simple keys 38 may be used on the sides and the-enlarged key shims 98 to expand the tool. In this case however, the drag bit assembly |84 employs separate drag bit elements |85 each of which is formed integral with the tool block |83 at the lower end (note details in Figs. 6, 7, and 8). In this case each tool blockhas parallel sides |86 and '|81 rounded at their outside lower ends |88 connecting these sides. The bottom |89 of each drag bit .element extends below the lower surface ||8 of the main portion of the tool block |83'. An inside vertical base extends inwardly from the side |81 and terminating this there is a face ||2 parallel to l the faces |86 and |81 and the faces |86 and ||2 i flrst attach the keys 38 or the shim keys 98 to Athe square section of the shank and slide the key blocks.|83 upwardly from the lower end of "the tool and then bolt these in place by the bolts in the same manner as described in Figs. 1 through 5. It will be noted when the tool is contracted as shown in Fig. 8 that there is a considerable overlap between the corners ||5 formed by the junction of the vertical faces ||2 and ||3 b'ut that there is a considerable space between the vertical inset face and the vertical end 'face ||3 of the two drag bit elements.

The junction of the faces |86 of these elements on the lower surface |89 forms the cutting edge of the drag bit elements.

The drag bit elements are provided with additional cutters and have end and marginal cutters |20, these being shown in elevation in Fig. 6 and in endview in Figs. 7 and 8. Each of these has a laterally extending cutting blade `|2| with a plane vertical front surface |22, the direction of rotation being that of the arrow |23. (Note Figs. 7 and-8.) These have a vertical edge |24, an inwardly sloping bottom edge 25, and a horizontal inward extension |25 thereof. Each of these blades has a bulbous inner end portion |26 which forms part of a cylinder and this fits in a cylindrical vertical recess |21 extending upwardly in the lower end of each tool block |03 in the portion forming the outside of the drag bit element |05. A lateral slot |28 extends from the curved surface |08 and communicates with the cylindrical recess |21. Thus these marginal cutter blades may be inserted upwardly from the lower end of `the drag bit elements and are held tightly in place by locking bolts |29 which have their heads |30 resting on the bottom of the cut-.out corner recesses |3| in Veach drag bit element |05, such recesses being spaced above the bottom |09.

In addition, cylindrical cutting teeth |35 are utilized in the drag bit elements each of which extends upwardly in a cylindrical recess |36 of each drag bit element, and is held in place by a set screw |31. The lower ends of these cylindrical teeth are shown as domed as indicated at |30 forming substantial hemisphercs at such ends. It is to be noted that these cutting teeth or pins |35 are located out of symmetry on the drag bit elements |05 there being three shown on o ne element and four on the other, and they are so spaced that the core left in the center of the tool is so small that it would break off and moreover, when the tool isexpanded to its greatest diameter .shown in Fig. '1, the corners I5 of each drag bit element |05 are practically contiguous at the center of the expanded tool.

From the above description it will be seen that with my construction of drill bit using the shank of square cross section the grooves and locking keys and locking key shims together with the removable tool holder blocks, I may readily change the rock drill having rotary cutters froma smaller to a larger diameter for cutting different sized holes. Also, by substituting two tool holder blocks with drag bit elements I may change the type of bit to one in which the drag bit is used as the main cutting tool and this may also be changed from a small diameter tool to a larger diameter tool in accordance with the size of hole to be drilled.

In connection with both" of these types of tools I use a set of reamers designated by the assemblyteeth,land other discs |54 have a sharp peripheral cutting edge. In the r ss |49 and on the shaft |5| there are tapered reaming tools |55, these having longitudinally extending teeth. Thus, it will beseen that no matter whether the bit is operating in a small or a large hole with the rock type ofv rotary cutters or the drag bit type of cutter, I obtain' a reaming action, and on account of the reaming tools being mounted-on each of the tool holding blocks these are assembled and disassembled from the shank when making changes in the type of cutters used for forming the hole.

The length of the cutter shaft 56 (note Fig. 5) may be adjusted to a slight extent due to the threaded connection between the threaded shaft support 63 and the outer portions 64. 'Ihis accommodates different sized cutters 60 between the webs 55. When a change is made, however, by either inserting key shims or removing these to contract the tool, the substitute end portion 64 must be used.

The screw threaded adjustment of the several sections of the shaft 56 will accommodate -changes in diameter if the shims do not diier greatly in size, and also accommodates these in different size cutters 61 on the outside of the webs 55.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. A bit having a shank with a plurality of sides, tool holding blocks, means to attach each to one of the sides of the shank, each block having cutters 13o-operate on the bottom of the hole, the attaching means having in part elements to space the said blocks from the sides of the shank, a diametrically opposite pair of tool blocks having a cutter supporting means interconnecting the lower portion of said latter blocks with cutters thereon, means attaching said latter blocks to the shank the said latter cutters being located below the bottom of the shank.

2. A bit having a shank,l with outside faces,v

a plurality of tool holding blocks each having inside' faces, a key between each shank face and block face, the shank and the block faces and the keys having an interlocking means, bolts for removably attaching the blocks and keys to the shank, lthe keys being of a type adapted to be interchangeable.

, 3. A bit as claimed in claim 2, the cutters on the tool blocks being of a rotary type and a shaft 4 extending between two of the blocks and having rotary cutters thereon below the bottom of the shank, the said shaft having means to accommodate a dilerent spacing of the tool holding blocks.

4. A bit as claimed in claim 2, a bearing block secured to the'bottom of the shank intermediate two opposite sides, a shaft mounted in the lower end of two of the diametrically opposite tool holding blocks, an extensible and contractible shaft having a mounting respectively in the said lower ends of the two blocks and the central bearing block and rotary cutters on the said shaft.

5. A bit as claimed inclaim 2, each of the tool holding blocks having substantially vertical shafts and each shaft having a plurality of rotary reaming tools thereon.

6. A bit as claimed in claim 2, two of the diametrically opposed tool holding blocks having each a drag bit element secured thereto at its lower end, each drag bit element having a portion thereof extending below the bottom of the shank. I

7. A bit as claimed in claim 2, two of the diametrically opposed tool holding blocks having each a drag -bt element secured thereto at its lower end, each drag blt element having a portion thereof extending below the bottom of the shank, each drag bit element having a plurality of cutters thereon, said cutters being detachable from the drag bit elements and extending downwardly below the lower edge of the drag bit elements.

8. A bithaving a shank substantially rectangular in cross section and having four equal size vertical faces, each vertical face having a vertical undercut groove, four tool holding blocks each having an inner vertical face with an undercut groove therein, the faces oi the shank and blocks being adapted to receive a plurality of keys each having two pairs of marginal tongues on vertical edges, the two pairs of tongues being spaced apart by the thickness of the key, the said key being insertable in the under cut grooves of the shank and the tool holding blocks, bolts attaching the tool holding blocks, the keys and the shank in an assembly, each tool holding block having cutting tools to operate on the bottom of the hole cut by the bit.

9. A bit as claimed in claim 8, two of the diametrically opposite blocks having each a downwardly extending web, said webs diverging outwardly,each of said webs having a stub shaft mounted therein and each stub shaft having rotary cutters, the other pair of diametrically opposite blocks each having a tool connected thereto and extending downwardly below the bottom of the shank, the said tool extending across the bottom of the shank.

10. A. bit comprising in combination, a shank substantially square in cross section and having four Vertical faces, a first pair of tool ,holding blocks attached on diametrically opposite faces of the shank, each block having a web at its lower end with rotary cutters mounted thereon, tool holding blocks on the remaining two opposite sides of the shank, said latter blocks having cutting tools mounted on their lower ends and extending across the shank below the bottom thereof, said shank having a central conduit for slushing fluid and a plurality of conduits located at about substantially the corners of the shank and between adjacent tool holding blocks.

1l. A bit, comprising in combination a shank substantially square in cross section and having four vertical faces, a rst pair of tool holding blocks attached on diametrically opposite faces of the shank, each block having a web at its lower end with rotary cutters mounted thereon, tool holding blocks on the remaining two opposite sides of the shank, said latter blocks having drag bit elements secured thereto, said shank having a central conduit for slushing fluid and a plurality of conduits located at substantially the corners of the shank between adjacent tool holding blocks.

12. A bit having a shank with four vertica faces, two pairs of diametrically opposite tool holding blocks, bolts securing each pair of blocks to the shank, one of the pairs of tool holding blocks having cutters extending diametrically across thebit below the shank, the other pair of blocks having rotary cutters. l

13. A bit as claimed in claim 12, the said cutters being mounted on a shaft, said shaft being secured to the lower ends of the first mentioned pair of blocks), the said cutters being rotary.

14. A bit as claimed in claim 12, the said pair of blocks having the cutters below the shank having such cutters rigidly secured to the lower ends of the said blocks, certain of the said fixed cutters being adapted to overlap.

E. L. TAYLOR,

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