US2214221A - Rock bit - Google Patents

Description

Sept. 10, 1940. Q CATLAND 2,214,221

ROCK BIT Patented Sept. 10, 1940 ROCK BIT Alfred C. Catland, Alhambra, Oalifi, assignor to Globe Oil Tools-Company, Los Nietos, Calif., a a

corporation of Californi Application November 5, 1937, Serial No. 172,967 7 Claims. (01. 308 -198) I This invention relates to well drilling tools and relates more particularly to a rock bit for use in the rotary method of well drilling. A general object of this invention is to provide a rock bit embodying improved and particularly effective anti-friction bearing means for the roller cutters.

Another object of this invention is to provide a rock bit embodying anti-friction ball bearings for the cutters in which the balls assume-the end thrusts in bothaxial directions, as well as the radial thrusts.

Another object of this invention is to provide a rock bit of the character mentioned in which the bearings for the cutters are simple and inexpensive to manufacture and are easily and quickly assembled.

Another object of this invention is to provide a rock bit of the character mentioned in which the balls are inserted in the ball grooves through notches in the race, the notches later being closed by blocks formed and located so that the race and blocks are not cracked or broken away by the balls during operation of the bit.

Another object'of this invention is to provide a dependable, inexpensive and practical means for removably attaching a cutter supporting pin or bolt to the body of a well bit.

The various objects and features of my invention will be fully understood from the following detailed description of a typicaLpreferred form and application of the invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. 1 is a side elevation of the well bit construction provided by this invention with the lower portion broken away to illustrate the outer cutters and the bearing means in vertical cross section. Fig. 2 is an enlarged side elevation of the bearing member or race of one of the cutter mounting means. Figs. 3 and 4 are transverse detailed sectional views taken as indicated bylines 3-3 and 4-4, respectively, of Fig. 2. Fig. 5 is an enlarged vertical sectional view of one of the blocks for occupying a ball admitting opening in the race and Fig. 6 is an enlarged side elevation of a split threaded thimble for one of the cutter supporting pins.

The improved rock bit provided by this invention includes, generally, a body I0, outer cutters I I and bearing means I2 for mounting the outer cutters II on the body Ill.

The bit body I 0 is intended to be connected with the lower end of a rotary well drilling string. A threaded pin I6 may be provided on the upper 65 end of the body I0 to facilitate its connection with the string; Depending parts are provided on the lower end of the body III to carry the bearing means I2 for the cutters II. A substantially central web I! projects downwardly from the lower end of the body Ill. The web I 1 is broad- 5 ened adjacent its lower end to have two downwardly and outwardly extending wings I8. Two diametrically opposite legs I9 project downwardly from the lower end of the body Ill. The legs I9 project outwardly as well as downwardly and the 10 inner sides of the legs I9 oppose the outer sides of the wings I8. In the preferred construction the opposing surfaces or sides of the wings I8 and the legs I9 are fiat and parallel and are inclined downwardly and outwardly relative to the central 15 longitudinal axis of the bit. The web I! and the legs I9 may be integral with the body I 0. It is to be understood that the bit body I0 may be pro vided with the usual circulation ports for handling the circulation fluid used in the rotary 20 method of well drilling. The bit shown includes cross cutters or inner cutters I3 and I4 arranged at opposite sides of the web l1.

The cutters II are toothed roller cutters for acting on the outer portion of the bottom wall of 25 the well. There are two outer cutters II embodied in the bit, one cutter II being supported between each set of opposing wings I8 and legs IS. The cutters II are frusto-conical having pitched toothed peripheries and having flat paral- 30 lel opposite ends. Each cutter II has a central longitudinal opening 2I of substantial diameter. Annular ball races or grooves are provided in thewalls of the cutter openings 2I. In the form of the invention illustrated there are two grooves 22 35 and 23 provided in the wall of each opening 2|. The grooves 22' are slightly larger in diameter than the grooves, 23. It is to be noted that the ball grooves 22 and 23 are of substantialdepth.

The bearing means I2 are in the nature of 40 anti-friction ball bearings for rotatably supporting the cutters II. As the two bearing means I2 may be identical I will proceed with a detailed description of one of them, it being understood that such description is equally applicable to the 45 other bearing means.

The bearing means I2 includes a bearing memher or race 24. The race 24 is a generally cylindrical spool-like member having a central longitudinal opening 25. The race 24 ispropor-' 5o timed to be received in the opening 2| of a cutter II with substantial clearance. The opposite ends of the race 24 are flat .and parallel and have central outwardly projecting bosses 26.

' Peripheral ball grooves 21 and 28 are provided in the race 24 to oppose the grooves 22 and 23, respectively, on the interior of a cutter The groove 21 is somewhat larger in diameter than the groove 28 and the two grooves are of substantial depth. Openings or axially extending notches 29 extend into the member 24 from its opposite ends to join the adjacent grooves 21 and 28. The notches 29 extend through the wall of the race 24 to the opening 25 and extend outwardly through the bosses 26. In the preferred construction the two notches 29 are circumferentially ofiset, as best illustrated in Fig. 2 of the drawing. The notches 29 have fiat parallel side walls.

The bearing means I2 further includes series of balls 38 cooperating with the sets of opposing grooves 22 and 21 and 23 and 28. The opposing grooves 22 and 21 and 23 and 28 are of such depth that the balls 38 have extensive cooperation with their walls to assume the end thrusts in both directions, as well as the radial thrusts transmitted between the cutter II and the race 24. The notches 29 are proportioned to admit the balls 38 to the pairs or sets of opposing grooves and in assembling the balls 38 they are individually passed through the notches 29 into the registering grooves 22 and 21 and 23 and 28, as will be subsequently described.

Blocks 3| are provided to occupy the notches 29 in the bearing member or race 24. The blocks 3| are'shaped and proportioned to fit and fully occupy the notches 29. The outer sides of the blocks 3| have curved concave faces 32 forming continuations of the grooves 21 and 28. When the blocks 3| are in place in their notches 29 their outer ends: are flush with the flat outer ends of the race 24. The blocks 3| are provided with outwardly projecting extensions 33 which occupy the portions of the notches 29 extending through the bosses 26. The inner sides of the blocks 3| are concave to be flush with and form continuations of the wall of the opening 25. When the blocks 3| are in place in the notches 29 the grooves 21 and 28 are completed by the surfaces 32 of the blocks so that the balls 38 are positively prevented from loss or displacement from the grooves. The balls 38 in turn cooperate with the registering or opposing grooves 22 and 21 and 23 and 28 to prevent relative endwise movement between the race 24 and the cutter I.

Means is provided to prevent outward displacement of the blocks 3| from the notches 29. An annular groove 35 is provided on the wall of the opening 25 midway between the ends of the race 24. The groove 35 has a deepened middle portion. The groove 35 is partially intersected by or is joined by the notches 29. The blocks 3| are provided with lugs or tongues 36 which project into the deepened portion of vthe groove 35. A snap ring 31 is sprung into the groove '35 to cooperate with the tongues 36 and there- 'by limit or prevent outward displacement of the blocks 3| from the notches 29. The tongues 36 and the adjacent portions of the blocks 3| are shaped to be properly engaged by the periphery of the ring 31. The ring 31 is a split resilient annular member that may be compressed and entered in the opening 25 to automatically spring into the groove 35 to cooperate with the tongues 36.

It is believed that it will be apparent how the bearing means I2 may be assembled in a cutter II. The race 24 is first arranged in the cutter opening 2|. The balls 38 are then passed through one of thenotches 29 to occupy one set of opposing grooves 22 and 21 or 23 and 23. When this set of grooves is fully occupied by the balls 38 a block 3| is inserted in the notch 29 to retain the balls in the grooves. The balls 38 are then arranged in the other set or pair of registering grooves 22 and 21 or 23 and 23 in the same manner. The other block 3| is then arranged in its notch 29. The ring 31 1s sprung into the groove 35 to cooperate with the tongues 36 for the purpose of retaining the blocks 3| in place. A washer 38 is arranged between the inner end of the race 24 and the outer face oi. the adjacent wing I8. The washer 38 fits in the opening 2| of the cutter II with suitable clearance and surrounds the boss 26 on the inner end of the race 24. The balls-38 in the grooves 23 and 28 cooperate with the washer 38 for the transmission of end thrusts from the cutter to the wing I8. The washer 38 is provided with a lug 39 which projects inwardly at the lower end of the wing I8. A washer 48 is arranged between the outer end of the race 24 and the inner side of the adjacent leg I9. The washer 48 surrounds the boss 26 on the outer end of the race 24 and extends into the cutter opening 2| with suitable clearance. The row of balls 38 in the grooves 22 and 21 cooperates with the washer 48 for the transmission of outward end thrusts from the cutter II to the leg I9. A lug 4| is provided on the washer 48 and pro jects outwardly at the lower end of the leg I9.

When a cutter II and its bearing means have been assembled, as described above, the assem-' bly, together with the washers 38 and 48 is arranged between a wing I8 and a leg I9 and theassembly is secured to the body I8. Each" wing I8 has a downwardly and inwardly inclined opening 42 and each leg I9 has a correspondingly inclined opening 43 aligned with the opening 42 of the adjacent wing I8. The outer portions of the openings 43 are enlarged and shaped to constitute frust'o-conical sockets 44. The means for supporting a bearing means I2 and its cutter consists of a bolt or pin passed inwardly through an opening 42 to extend through the opening 25 in the race member 24 of the bearing means. A frusto-conical spool or nut 46 is arranged in the socket 44 in the adjacent leg I9 and the outer portion of the pin 45 is threaded into the nut. The nut 46 is longitudinally split,'as illustrated in Fig. 6, to render it flexible and resilient. The outer end 46 of the nut 46 is pitched to be flush with the outer side of the leg when the nut is in place. A head 48 is provided on the inner end of the pin 45 to engage against the inner side oi! the wing I8. When the pin 45 is tightened the taper of the nut 46 and the wall of the socket 44 causes the nut to contract tightly onto the pin 45. This prevents loss or displacement of the nut 46. The tightening or wedging of the nut 46 onto the tapered socket 44 also compensates for any inaccuracies there may be in the nut and the wall of the socket. Following the tightening down of the pin 45 the lug 39 is welded to the lower end of the wing I8 and the lug 4| is welded to the lower end of the leg I9 so that the washers 38 and 48 are fixed to the bit body.

In assembling the bearing means I2 and the 24 and to prevent the race from moving from wear. To assure the proper location of the race the proper place a dowel 41 may be assembled in aligned openings in the .outer end of the race and the washer 40. As the washer 40 is welded to the leg IS the dowel 41 serves to prevent turning of the race 24.

It is believed that the utility and practicability of the improved well bit provided by this invention will be readily understood from the foregoing detailed description. In operation the bit is secured to the lower end of the drilling string which is rotated and fed downwardly in the well in the usual manner. The cutters ll follow an annular path to cut away the formation at the outer portion of the well bore. The cutters H are supported by the pairs of series of balls 30 to freely rotate about inclined axes. The balls 30 are operable to transmit end thrusts in both axial directions as well as the radial thrusts so that the cutters do not bear against the body surfaces or the thrust washers. The races 24 are long wearing because the notches 29 are at their upper sides where the blocks 3| and the parts adjacent the notches 29 are subjected to a minimum of pressure and wear. The bearing means l2 of the cutters II are easy to manufacture and are simple to assemble.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. In combination, a rotary element having an opening and a ball groove in the wall of the opening, a tubular race in the opening having an internal annular recess and an external ball groove between its ends opposing the first named groove and having a notch extending inwardly from one end and joining the second mentioned groove, balls inserted through the notch to cooperate with the grooves, a block filling the notch, and means for retaining the block in the notch comprising a tongue on the block extending into the recess, and a spring ring in the recess cooperating with the tongue.

2. In combination, a. rotary element having an opening and spaced ball grooves in the wall of the opening, a tubular race in the opening having spaced races opposing the races in the element, and having a notch extending from one end to one of the last named grooves and a notch extending from the other end to the other of the said last named grooves, balls introducedthrough the notches to the pairs of opposing grooves, blocks inserted in the notches to com plete the said last named grooves, and a single spring ring in the race retaining the blocks in the notches. I

3. In combination, a rotary element having an opening and spaced ball grooves in the wall of the opening, a tubular race in the opening having spaced races opposing the races in the element, and having a notch extending from one end to one of the last named grooves and a notch extending from the other end to the other of the said last named grooves, balls introduced through the notches to the pairs of opposinggrooves, blocks inserted in the notches to complete the said last named grooves, and means on the race retaining the blocks in the notches, said means including tongues on the inner ends of the blocks, and a ring in the race cooperating with the tongues.

4. In combination, a roller having an opening and spaced ball grooves in the wall of the opening, a tubular race in the opening having spaced races opposing the races in the roller, and having a notch extending from one end to one of the last named grooves and a notch extending from the other end to the other of the said last named grooves, balls introduced through the notches to the pairs of opposing grooves, blocks inserted in the notches to complete the said last named grooves, and means on the race retaining the blocks in the notches, there being a groove in the interior of the race, said means including tongues on the blocks extending into the groove in the interior of the race, and a spring ring in the said groove cooperating with the tongues.

5. In combination, a roller having an opening and a ball groove in the wall of the opening, a tubular race in the opening having a ball groove opposing the first named groove and having a notch extending inwardly from one end and joining the second mentioned groove, balls inserted through the notch to cooperate with the grooves, a block filling the notch, andmeans carried by the race retaining the block in the notch, said means including a tongue on the block recessed in the interior of the race and a spring ring in the race cooperating with the tongue.

6. In combination, spaced supporting parts, a roller arranged between said parts and having an opening with a ball groove in its wall, a support extending between said parts and passing through said opening, a race on the support having an external groove opposing the first mentioned groove, a boss on an end of the race, the race having a notch extending from: said end through the boss to the said external groove, balls inserted through the notch to the grooves to rotatably support the roller, a block occupying the notch, an extension on the block occupying the portion of the notch in the boss, and a washer on the boss between said end of the race and one of said parts cooperating with the extension and a side of the block.

'7. In combination, spaced supporting parts, a rotary element arranged between said parts and having an opening with a ball groove in its wall, a support extending. between said parts and passing through said opening, a race on the support having an external groove opposing the first mentioned groove, a boss on an end of the race, the race having a notch extending from said end through the boss to the said external groove, balls inserted through the notch to the grooves to rotatably support the element, a block occupying the notch, an extension on the block occupying the portion of the notch in the boss, the notch and block being at the upper side of the race, a washer on the boss between said end of the race and one of said parts cooperating with the extension and a side of the block, means holding the washer against rotation, and means securing the race to the washer to prevent rotation 01' the race.

ALFRED C. CATLAND.

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