US1692919A - Disk-drill bit - Google Patents

Description

Nov. 27|, 192s.

W. C. BAILEY DISK DRILL BIT Filed March l17, 1924 Patented Nov. 27, 1928.

' UNTTED STATES WALTER C. BAILEY, OF NORWALK, CALIFORNIA.

msx-DRILL Brr.

Application filed March 17, 1924. Serial No. 699,805.

This invention relates to disk drill bits such as are used for the drilling of wells; and it relates particularly to improvements which will overcome many of the disadvantages of the present types of bit.

It is an object of the present invention to provide a rotary disk bit having a single depending disk-supporting leg provided with independent disk-supporting pins, each extending entirely through said leg in a separate pin-receiving opening, whereby each pin has a supporting bearing throughout the entire thickness of said leg so that the dimensions of said leg may be restricted to contribute to a structure of relatively thin crosssectional character which will permit a positioning of the opposed disks in close relationship on opposite sides of the vertical axis of the bit, and which will function as an agitating means to maintain the fluid at the bottom of a well bore in a state of violent agitation to promote a quick removal of the drilling detritus and prevent mudding-up of the bit.

above character in which the disk-supporting pins may be of relatively large size, and in which the disks are positioned to engage thrust-receiving surfaces extending to quite near their cutting peripheries.

Another object is to provide an arrangement of the above character in which the pins and disks are arranged so that a removal or loss of a disk in a well bore will have no effect upon the remaining disk and its bearing.

A further object is' to provide a disk bit of the above type in which the disks are disposed in advance of said leg relative to the rotation of the bit and positioned so that the cutting is performed by the following or trailing edges of the cutters.

Another object is to provide a cutting disk formed to turn cutting detritus away from its forward face.

Another object is to provide a disk bit of the above type in which the wear-receiving parts are both rugged and easily removable, and which will be economical t0 manufacture, to operate, and to maintain in operative condition.

Further objects and advantages will be made evident hereinafter.

Referring to the drawings, which are for illustrative purposes only,

A further object is to provide a bit of the i Fig. l is a side elevation of a disk bit which embodies various features of my invention.

Fig 2 is a horizontal section taken as ndicated by the line 2 2 of Fig. l. Figs. 3 and 4L are diagrammatic vieW's, illustrating the manner in which the disks are rotated.

Rotary diskbits are generally designed to function upon one of two distinctly different theories of cutter action. In one type, the disks are disposed so that the cutting is performed by the forward or leading portions of the peripheries of the cutters, and in the other they are disposed so that the cutting is performed by the rearward or following portions of the peripheries of the cutters. In the first the rotation of the bit tends to revolve the individual disks so that the leading portions of their cutting edges travel downwardly while the friction On the side wall of the bore, during descent of the bit, tends to revolve said disks. in a reverse direction. Thus there are two opposedforces which, when equalized, will maintain the disks against rotation and so cause them to wear Hat on one side. In the second type above mentioned these two forces are exerted in coincident directions, thus insuring a constant revolving of the disks such. as is most desirable in disk bits.

The severe strains to which the disks are subjected make it exceedingly desirable that their bearing pins be of relatively large d i-y ameter and the tilting strains occasioned by the angular disposition of the disks renders it desirable to support the disks, so that the thrust be towards the support instead of away therefrom, this tilting influence also rendering it advantageous that said support present as large al thrust-receiving surface as possible so as to engage the disks as near their cutting peripheries as possible without interference with the cutting action.

In certain types of disk bits the disks are carried by respective independent legs depending from the bit body, each disk being positioned adjacent the inner side of its supporting leg. The forging of such a body is very expensive. In another type, each disk is positioned between a central depending leg and an outer depending leg with its bearing pin supported at opposite ends in both legs. Bits of this character are so expensive that they are not generally used in the oil industry .excepting when equipped with toothed rollers suitable for boring in hard rock, in place of plain disks. Such 4bits are very liable to mud-up due to the obstruc tion presented to a free removal of the drilling detritus by the supporting legs. In another type of disk bit havin a single supporting depending leg, the disk-supporting pins are formed integral with the body. A body of this type is expensive to manufacture and is an economic failure for the reason that if one of the pins fracture or its threads become damaged, the entire body must be discarded. It has heretofore been proposed to provide a single supporting leg carrying removable and replaceable bearing pins for cutting disks, but these pins are ordinarily offset so slightly as to prevent each from extending morev than half way through the supporting leg, or they are intermeshed and dependent upon each other for securance in said leg; in either case the leg must be of considerable width to properly support both pins. Such a construction is not desirable as it prevents the opposed disks from being positioned as near the axis of bit rotation as is desired, and for the further reason that it presents a bulky structure which is quite likely to mud-up, it being stated that there is a decided advantage in providing a bit relatively thin in one transverse direction so that the bit will func-tion in the manner `of an agitator to keep the circulation fluid in the bottom of the well bore in a state of violent agitation.

The desirable features above enumerated are present in the disk bit herein disclosed and the structure is particularly designed to eliminate the disadvantages of the several types of disk bits heretofore produced.

The drill bit shown in the drawings comprises a body 11 having a centrally disposed leg 12 extending therefrom and optionally arranged coaxially of the body 11. A usual threaded pin 13 may be provided at the upper end o-f the body 11, for securing said body to a drill string. T'he leg 12 is preferably of a substantially rectangular cross section, as shown; andy it may be arranged symmetrically with reference to a central plane- -b, including the longer horizontal diameter of said leg. Eccentrically located holes 15 may be provided in the leg 12, and extending at right angles to the plane -b, through which securing pins 16 may extend to provide laterally offset supports for cutting disks. The pins 16 may comprise cylindrical portions 17, adapted to lit in the holes 15, and they may have hexagonal or other non-circular heads 18 which are shown as resting in countersinks or recesses 19, `this construction being intended to make the pins non-rotatable. The pins 16 may protrude in opposite direcu tions, as shown, so that their threaded portions 20 are on the opposite sides of the leg 12.

To provide extensive and replaceable bearing surfaces, rugged and hardened bushings 22 may be threaded o-nto the extending portions 20 of the substantially parallel horizontal spindles or pins 16, in such a manner that they may clamp said pins 16 rigidly in place; and they may serve to secure removable thrust washers or wear plates 24, which are preferably so broad as to extend to the edges of the leg 12. Each bushing 22 may be internally threaded at 26, and each may have a hardened bearing surface 27, on which a rotary disk cutter 28 may be rotatably mounted. The bushings 22 may be locked in 'place by means such as the lock nuts 30, which may be threaded on the reduced ends 31 of the pins 16 and which may fit in countersinks or recesses 32 of said bushings.

The disks 28 may provide peripheral cut-l ting edges 33 disposed as shown in Fig. 2. Each -disk may be externally rounded t-o provide clearance behind a cutting edge, the front surface of which may be formed by a concavity comprising an outer conical area which may be of such form that, when a pair of disks are mounted in the offset relationship shown, a line connecting the extreme outer points of a pair of disks will lie in the conical surfaces o-f both disks. At the extreme points referred to, the conical surfaces will evidently lie at an angle not exceeding degrees tothe Wall of the hole, or on radii of the bit, this relationship being favorable to effective. cutting without undue wear.

As mentioned, it is desirable to provide a bit in which the disks will rotate continually in one direction regardless of the hardness of the rock encountered, and, in ord-er to accomplish this, it is necessary that friction-on the bottom and at the sides of each disk tend to rotate it in the same one direction. As shown in Fig. 3, when the bit is progressing downwardly, as indicated by the arrow 40, the friction on thesides of the disks, caused by this contact `with the sides of the hole, tends to rotate the disks as indicated by the arrows 41. During its advance, the bit is intended to be rotated in the direction of the arrow 43, in Fig. 4. The cutting faces of the disks 28 are arranged so that they extend' in planes as indicated by the line c-c, which pass in front of the central leg-bisecting' diametric plane b-b, extending through. the vertical axis of rotation -a and including the longer horizontal diameter of the leg 12, from which the pins 15 extend perpendicu- `larly. Taking, for illustration, the points 44, which are the lowermost points on the disks, these points being in the vertical planes 0-0 of the disks, the locus of all points 44 may be represented by the line 45. An arrou7 46 may then represent the opposition of the rock, tending to rotate the lower portions of the disks in the direction indicated by the arrow 47, and it will be seen that this compo nent is eiective in the same direction as the arrow 41, representing the rotative tendency due to lateral engagement incidental to descent. Similar results may be accomplished by placing the cutting edge in other planes parallel With and in front of the plane b-b (passing through the center ot the head and parallel With the cutting faces) and Water or slush ducts D may be arranged as desired.

When the bit is being rotated, the cutters Contact With the Wear or thrust plates 24 at points affording adequate support near the cutting edges 33. Instead of interposing additional Wear plates between the shoulders or flanges 51 of the bushings 22 and the correspending surface 52 of a disk, I may shorten and recut or merely replace my Worn bushings; and it is an especial merit of the construction herein shown and described that, referring, for example, to the relationships between the points X, Y and Z of Fig. 2, and regarding X as a point at Which pressure is applied and-Y as the fulcrum of a lever, the arm YZ is very long in comparison with the arm XY. Most ot' the Wear may therefore come on `the Wear plates 24.' The threads on pins 16 may be such that the normal rotation of the disks shall tend to tighten the bushings thereof (suitable clearance being provided to permit free rotation of the disks 28) and, to assure a locking action, the lock nuts 8() may be provided With threads of an opposite or different pitch. It Will be understood that, although my bushings, Wear plates and disks are intended'to be conveniently replaceable, any or all of these parts may be initially formed Wholly or partly of an exceptionallyl hard material, such as a tool or special steel; and although I consider it desirable to support the disks 28, when lateral adjustment is not required, from a single leg, not all of the advantages of my invention are dependent upon this or any specific mode of support. The line X-X may advant-ageousv ly form an angle of about 22 degrees With the line b-b, and the fronts of my disks may advantageously be made harder than their backs.

Although, I have herein described, in detail, but one speeilic embodiment of my invention, it should be understood that various features thereof may be separately or collectively embodied in other constructions Within the scope of this invention.

I claim as my invention:

l. In a rotary disk drill bit, the combination of: a body rotatable about its vertical axis and having a cent-ral depending leg; two rotatable cuttingl disks supported entirely by and mounted on opposite sides of said leg and transversely offset relative to each other in opposite directions from the vertical axis of the body, each disk being in advance of said leg in relation to the cutting rotation thereof and an independent supporting bearing pin for each disk, each bearing pin extending entirely through said leg.

2. In a rotary disk drill bit, the combination of: a body rotatable about its vertical A axis and having a central depending leg; two

rotatable cutting disks supported entirely by and mounted on opposite sides of said leg and transversely odset relative to each other in opposite directions romthe vertical axis of the body, each disk being in advance of said leg in relation to the cutting rotation thereof; and an independent supporting bearing pin for each disk, said bearing pins extending entirely through said leg and being horizontally parallel to position the disks in relative parallel vertical planes.

3.' In a rotarydisk drill bit, the combinat-ion ot' a central supporting leg adapted to be rotated upon a vertical axis; olset disks entirely supported by said leg .and mounted thereon in advance of the major vertical axial plane of said leg; and mounting means for each of said disks including an independent removable pin rigidly secured in said leg.

et. In a rotary disk drill bit, the combination of: a central supporting leg adapted to be rotated upon a vertical axis; ott'set disks entirely supported by said leg and mounted thereon in advance of the major vertical axial plane of said leg; and mounting means for` each of said disks including an independent removable pin rigidly secured in said leg and having intermeshing engagement therewith to prevent rotation of said pin.

5. In a rotary disk drill bit, the combination of: a body rotatable about its vertical axis and having a central depending leg; two rotatable cutting disks supported entirely by and mounted on opposite sides of said leg and transversely oli'set relative to each other in opposite directions from the vertical axis of the body, each disk being in advance of said leg in relation to the cutting rotation thereof; yand mounting means for said disks'including independent relatively spaced removable pins, each extending entirely through said leg and restrained against rotation by intermeshing engagement with said leg.

6. Ina rotary disk drill bit, the combination of: a body rotatable about its vertical axis and having a central depending leg provided With two horizontally spaced nonintersectingtransverse openings extending therethrough; a bearing pin removably secured in each opening and restrained against rotation, each pin being inserted from one side of said leg with its free end projecting beyond the opposite side ot the leg; and a cutting disk rotatably lnounted upon the free end of each pin.

7. In a rotary disk drill bit, the combination of: a body rotatable about its vertical axis and having a central depending leg; two rotatable. cutting disks entirely supported by and mounted on opposite sides of said leg and in relative offset transverse rela-tion on opposite sides of the vertical axis of the body, each disk being in advance of said leg in relation to the cutting rotation thereof; and an independent supporting bearing for each disk, said bearings each comprising an independent pin extendingentirely through said leg and a bushing screw-threaded thereon and and clamping said pin in the leg.

8. In a rotary disk drill bit, the combination of: a body rotatable about its .vertical axis and having a central depending leg; two rotatable cutting disks entirely supported by and mounted on opposite sides of said leg and in relative offset transverse relation on opposite sides of thevertical axis of the body, each disk being in advance of said leg in relation to the cutting rotation thereof and an independent supporting bearing for each disk, said bearings each comprising an independentl pin ext-ending entirely through said leg, a bushing screw-threaded thereon and clamping said pin in the leg, and a lock nut screwthreaded on the pin and engaging the bushlng.

9. In .a rotary disk drill bit, the combina- 4tion. of: a body rotatable about its vertical axis and having a depending leg provided with two transversely adjacent relatively parallel nonintersectin g openings bearing pins in said openings, each pin extending outwardly from said leg in a direction opposite to that of the adjacent pin; securing means engaging the projecting end of each pin and overlapping the head of the adjacent pin; and a cut-ting disk journaled on the projecting end of each pin.

10. In a rotary disk drill bit, the combination of: a body rotatable about its vertical axis and having a depending leg provided with two transversely adjacent relatively parallel nonintersecting openings; bearing pins in said openings, each pin extending outwardly from said leg in a direction opposite to that of the adjacent pin; wear plates engaging the projecting end of each pin and overlapping the head of the adjacent pin; bushings screw-threaded on the pins and clamping the pins and Wear plates in place; and a cutting disk journaled on each bushing.

11. In a rotary disk drill bit, the comb-ina.- tion of: a body rotatable about a vertical axis and having a relatively thin central depend ing leg provided with two nonintersecting openings spaced horizontally from each other in opposite directions from said vertical axis; two disk supporting pins disposed in said openings to project respectively from opposite major vertical faces of said leg; two cutting disks; and means for rotatably mounting a disk upon each of said pins, where these pins project from said major faces.

12. In a rotary disk drill bit, the combination of: a body rotatable abo-ut a vertical axis and having a relatively thin central depending leg provided with two nonintersecting openings spaced horizontally from each other in opposite directions from said vertical axis, said openings extending entirely through said leg; two disk supporting pins disposed in said openings to project respectively from opposite major vertical faces of said leg, said disk supporting pins having head portions shaped to prevent said pins being passed entirely through said openings; two cutting disks; andrneans for rotatably mounting a disk upon each of said pins, where these pins project from said major faces, said means preventing movement of said pins from said openings.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 6th day of March, 1924.

WALTER c. BAILEY.

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