US1957476A - Swiveled drill bit for cable tool drilling - Google Patents

Description

8, 1934. E. s. sLoAN 1,957,476

SWIVELED DRILL BIT FOR CABLE TOOL DRILLING *l Filed Oct. 14. 1951 T157 is 3L INVENToR magi; 292?? L16: 620cm,

@QM Mm l ATTORNEY STATES PATENT. OFFICE. 'l

SWIVELED DRILL BIT FOR CABLE TOOL DRG Elgan S. Sloan, Shippenville, Pa.

Application @ctober 14, 1931, Serial No. 568,842

` 5 ciaima (ci. ass-72) This invention relates to improvements in drilling apparatus, more particularly in drill bits for use in connection with cable tool drilling rigs, and the objects of the invention are as follows:-

First, to provide a reciprocatory drill with a bit and carrier each having matching shoulders above and below an interposed ball annulus so as to confine the major impact to the shoulders and guarding the vballs against possible shearing and the edges of the races against possible chipping, said ball annulus further providing a swivel mount for the bit.

Second, to provide the drill bit both with an internally shouldered structure and a downwardly tapering bore for the respective purposes of establishing a rest or ledge for the support of the fragments of the core and for the establishment of an annular wedge space around the cylindrical core, said space when becoming impacted with fragments enabling the fragments A andthe tapering walls of the bore to operate as a combined gripper against the core so as to break it off and enable bringing it to the surface when the drill is extracted from the hole.

Other objects and advantages will appear in the following specification, reference being had to the accompanying drawing, in which Figure 1 is a vertical section of a cable drilling tool particularly illustrating the swiveled drill bit which is the principal subject of this invention,

Figure 2 is a partial inverted plan view of the swiveled cutting bit particularly illustrating the peculiar type of teeth which not only embody cutting edges but also constitute the means whereby turns are automatically imparted to the cutting bit when the bottom of the well hole is impacted,

Figure 3 is a fragmentary elevation of the drill bit, again illustrating the foregoing teeth.

The foregoing objects of the invention are carried out in the following structure, particular reference being first. made to Figure 1:-The lowermost end section 1 of tubing or other sus,- pending device which may be regarded as of any length, has an internally threaded portion 2 into which a filler 3 is screwed. This filler includes an annular flange 4, the top surface 5 of which' will bear tightly against the -bottom end 6 of the section 1 when the ller 3 is screwed home.

It is a matter of choice whether or not the joint at the place 5, 6 shall be welded as at 7. Ordinarily, for the. sake of security, the joint will be welded thusgirecluding any possibility of the filler 3 loosening while the drill is in operation.

Lit in place on the carrier 9. The term lock In practice the filler 3 will preferably be made of a tough variety of steel primarily to prevent its showing any fault during the strenuous service to which it is subjected. It is to be observed that the bottom surface .8 of the flange 4 is considerably wider than the top surface 5. This is, v of course incidental to the construction of the filler 3, but the fact of the surface 8 being wider than the surface 5 has the following important advantage: 65

The end 6 of the tubing 1 is comparatively narrow. If the thrusts of the drilling operation were imposed directly on the bottom end 6 there is the possibility of the bottom spreading or becoming bruised. By interposing the ller 3 and especially the annular flange 4 with its wide surface 8 there is considerably more area over which the impacts of the tool can be distributed, thus guarding the bottom end 6 of the tubing 1 from the dangers mentioned.

1 Inside of the filler 3 there is what is herein known as a carrier `9 inasmuch as it carries the cutting bit 10. The carrier 9 is externally threaded to be screwed home in the internally threaded ller 3, and when screwed home the top-surface 11 of a head 12 makes a Very tight contact with the foregoing bottom surface 8 of the flange 4. The so-called head 12 is virtually an annular flange similar to the flange 4, but ,the distinction is made because of the larger proportions of the head 12.

The bottom end structure of the carrier 9 includes shoulders 13, 14 and a connecting vertical wall 15 in which half 16 of a ball race is formed. The complemental half 17 of this race occurs in o the cutting bit 10 which has shoulders 18, 19 and avertical wall 20 matching thel corresponding parts of the head 12.

A ball annulus 2l occupies the race 16, 17. The v balls are introduced through a side opening 22 which is later plugged by a screw 23 or its equiv.- alent. The ball annulus is much on the order of any ordinary ball bearing although it does not include a cage. vThe chief purpose of the balls is to act as keys between the carrier 9 and cutting bit'lo, sole dependence being put on these balls to prevent the dropping away of the cutting bit from its carrier means 9. The balls simultaneously provide a. swivel mount for the bit and lock means prevention of endwise movement only.

So far it will be understood that the drill bit assemblage, generally denoted 24 comprises what might be called a stage construction, that is to say, comprises a plurality of parts which nt into u@ its support not'only while that part is intact but also in the event of its having become'crackedf This is best understood by considering the cutting bit 10 first. Suppose lthe cutting bit were split in half vertically. 'I'here would be no possibility of the parts dropping out because of the key function that the balls 21 perform. It is even conceivable that the cutting bit 10 would continue Lperforming this function properly even though split vertical into two or more fragments.

The same principle of holding together applies to the carrier 9 and filler 3. In the event of the carrier 9 becoming split its threaded engagement inside of the filler 3 wouldY hold the parts together. In the event'of the filler 3 becoming split theinternal threaded portion 2.of the tubing 1 would again holdthe parts together. It is the fact of these various components being successively secured inside of each other that insures the holding together of the broken parts in the event that a breakage occurs.

The cutting. bit 10 is provided with teeth 25, 25 of a peculiar formation. 'The bezel 25b of each tooth stands; on a decided incline in one direction as clearly shown in Figure 3. The in' clination may be in one Vor the other direction, but the specific inclination in Figure 3 is chosen because the reaction of the teeth against the solid substances at the bottom of the well hole will cause a reaction in the direction of the arrow 26 (Fig. 3), this being a clockwise direction to agree with the threads of the carrier 9 and filler.VVV

3 which are herein regarded as being righthanded. e.

From' the foregoing statement. it will be understood that incidental dependence is put on the shape of the teeth 25 in keeping the carrier 9 and filler 3 screwed up tight. Of course, in the event that the joint 5, 6 is welded at 7 there would be no possibility of the filler 3 unscrewing from the tubing section 1, but the carrier 9 will not ordinarily Ybe welded in place and therefore the foreging reactionof the teeth 25 is an important aid to keeping the carrier 9 in place.

Each tooth 25, 25a includes a component'27 `which generally falls in the zone 28a (Figs. 1 and 3). 'I'his component is angled bothin respect to the longitudinal and transverse axes of the drill bit. It is this component that virtually establishes the inclinationof the teeth as will be noted by tracing the direction of the teeth from. the bottom of the zone 28. Alternate ones o f theteeth 25 extend farther under the rounded terminal 2B of the cutting bit 10 (Fig. 1) than the intermediate teeth 25%, the former ending at points 29 (Fig. 1) which, when considered collectively in the circumferential direction, constitute the boundary of a bottom opening Vin. the cutting bit 10 communicating with the flaring bore 30 whichroccurs both in the cutting bit 10 and the carrier 9. This bore when considered from the other direction, that is to say reading down from the top, is downwardly tapering, and is intended to perform a very important function as Will presently be brought out.

Alternate `ones 25E of the cutters extend inwardly under the rounded terminal 28 a lesserY distance than the cutters 25 as denoted at 299' to provide unobstructed courses for the up flow= ing liquid. The inner walls 29b of teeth 25a merge with the otherwise solid walls 29c of that 'I'he teeth'25 extend inwardly a little farther than teeth 25 as at points 29 whence they taper to points of mergence with.the bore 30.V The portlons 29d of teeth 25 extend inwardly Abeyond the walls 29b`of the teeth 25 and serve as cutters or shears.

All of the teeth 25, 25'n havevextensiuns 31 under the -body of the cutting bit Yas already brought out, these extensions being provided witl cutting edges 32 backed up by the bezel 25 ineach instance, which 'edges do the major work on each down stroke of the drill bit assemblage. Ordinarily these cutting edges do not extend into the zone 28, The tooth components 27 occurring in this zone (Fig. 3) do, however, have a shearing action against the walls of the hole and also aid in turning the cutting bit. The components 27 are of minor extent when compared with the full length. of the teeth so that any tendency toward retrograde- 'turning of the cutting bit 10 by virtue of the engagement of the components 27 with the walls of the hole on the up stroke will be negatived by the far greater Iturns .imparted to the bit by thel longer tooth expenses extending under the bit.

lIt will now be understood that the bezels 25b of the teeth 25, 25 in Vstriking the solid substances at the Ybottom of the hole, will reactl in the direction of arrow 26 (Fig. 3) and cause a turn of the, bit 10 at the end of every down Ystroke of the drill bitV assemblage 24, thereby to successivelyadvance the teeth to new positions each time so that successive strokes will occur at different places in the bottom. of the holes and so exercise acontinuous cutting action.

It is further understood that the teeth 25 are arranged in annular series, that is to say there are Ateeth all around. When a down stroke is madeall of the cutting edges of the teeth are made to strike the bottom of the hole simultaneously. This producesV an annular series of spaced cuts.

Reverting. to the shoulder formations of the cutting bit 10 and its carrier 9, it is to be observed thatthe matching shoulders 13, l8rrand 14,19 occur below and above the ball annulus the cutting action of the internal cutters 299.

This core is cylindrical, and being so defines with the tapering bore 30k an annular wedge space 34. Cuttings will continually be failing into this wedge space' but during theY drilling operation will be washed out by water streams which ilow down in the direction of arrow 35 and uprin the direction of arrow 36. l

But when extractingVV the drill assemblage 2e from the hole the water stream naturally is cut olf and cuttings will be permitted to settle and pack in the annular wedge space 34. Some of the cuttings and even large fragments of the core itself will build up across the top ledge 37 which is formed by the upper parts of the ller 3 and the carrier 9.

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portion of the bore 3CB occurring in the bit l0. `Now-when the tool is extracted from the hole 150* ing walls of the bore and so coact with said walls as to form a grip onl the core 33, break it oif and carry it up with thetool.

Somewhere in the tubing there will be provided a check valve 38 which comprises a pair of leaves which are'so hinged at 39 as to enable the leaves to close against' the' walls of the respective tubing section by gravity. The,top of the tubing :is secured to a jointl 40 vof which the coupling pin 41 is a part. This coupling pin will be connected with the standard drill jar and rope'socket, which in turn is moved'up and down by the walking beam.

The action of the check valve 38 simulates the action of the foot valve of a pump. Asthe apparatus is vreciprocated in the well hole, the .water and liner cuttings carried thereby will be alternately permitted to pass the check valve and to be lifted thereby. On each down stroke the leaves of the check valve will move toward l each other to let the stream past, while on the up stroke the leaves will fall against the walls of the tubing -section and lift the superimposed liquid column. 'I'heheavier 'cuttings will gravitate toward the bottom of the tubing string, but

`inasmuch as these are agitated onevery stroke of the drill bit assemblage there will be no possibility of their clogging the mechanism.

The operation is readily understoodA and briefly reviewed as follows: The drilling tool is of the reciprocating type, the tubing being moved up and down in the well hole, 'a cutting Iaction'occurring every time vthe cuttingbit 1Q strikes the substancerat the bottom.

It is when the cutting bit strikes the bottom that it automatically partakes of a turn, the

The ball annulus 21 is solely-relied upon-to keep the inserted cutting bit 10 in place, and in order-to avoid damaging they balls the impact of the` cutting stroke is delivered tothe matching shoulders 13, 18land 14, 19. At this point it is well to observe that the places loi.' contaci; 6, 5'; 8,11 and 13, 18 become progressively larger toward the bottom of the drilling bit assemblage. 'Ihe greater portion of the thrusts is thus disseminated beforethe bottom end 6 of the section; is reached. This arrangement avoids damage to the bottom of the drill section. l

The tapering configuration of the bore 30 enables the drill assemblage to convert its own cuttings into a sample taker. Inasmuch as 'the core 33 is cylindrical it follows that' the annula'r space 34 will be of a cylindrical wedge shape.

Cuttings will settle in this space when the flow sembIage, and teeth on the cutting bit having ofwater is cut oi, and these same cuttings will be packed so hard in the space 34 by virtue of the tapering bore 30 when the bit assemblage 24 is reached that they will exercise a grip on the core 33, break it oli and bring it to the surface.

I claimrl 1. In reciprocatory drilling apparatus, a cutting bit having a top shoulder, carrier means for the cutting bit with` which said bit is intertted. said carrier means having a bottomfshoulder, and a ball annulus between the interiitted portions of the carrier means and bit providing a swivel mount for the bit on the carrier means to pr'el vent the bit from dropping out, said shoulders contacting to receive the thrust of an impact andV prevent the shearing of the balls.

2. In a reciprocatory drilling apparatus, a drill bit assemblage comprising a cutting bit,` means to swivelly support said cutting bit in said assingle bezels all inclined toward a cutting edge at a place of mergence with a substantially upright wall causing a reactive movement of the bit against a solid substance when struck during the downward movement oi.' theiassemblage -and a responsive turn of the cutting bit on its swivel support. v

3. In a reciprocatorydrilling apparatus, a drill bit assemblage carried by a reciprocable suspending device, lsaid assemblage including a cutting .105 bit, carrier means interposed between the cutting I bit and said device from which means the cutting bit is directly suspended, and a ball annulus between the cutting bit and said carrier means, said ball annulus constituting a locking -means for the cutting bit. y 4. In a reciprocatory drilling apparatus, a drill bit assemblage, said assemblage including a carrier, said carrier having a vertical wall with shoulders atv the ends thereof occupying parallelplanes, I

a cutting bit, teeth on the cutting bit having bezels respectively disposed in one direction and thereby subject to a reaction upon striking a solid substance to impart a turn to the cutting bit assemv blage in the same direction, a vertical `wall invcluded in said cutting bit, said wall fitting inside of the carrier and having shoulders matching those o1' the carrier, the then confronting walls having matching halves of a ball race, said'matching shoulders-lv receiving the impact of a working stroke, and aball annulus in said ball race comprising with said race the sole supporto! the cutting bit on.- the carrier but being guarded against damage on each working stroke by virtue of the engagement of the matching shoulders.

5. 'A reciprocatory drill bit assemblage for wedging a core, `said assemblage comprising a. toothed cutting bit, a carrier for supporting the cutting bit, and means for swiveling the bit on the carrier, said cutting bit and carrier having v l ELGAN s. swim. 14o

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