US3269469A - Solid head rotary-percussion bit with rolling cutters - Google Patents

Solid head rotary-percussion bit with rolling cutters Download PDF

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US3269469A
US3269469A US336942A US33694264A US3269469A US 3269469 A US3269469 A US 3269469A US 336942 A US336942 A US 336942A US 33694264 A US33694264 A US 33694264A US 3269469 A US3269469 A US 3269469A
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bit
cutters
cutter
ring
bearing
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Jr Joseph L Kelly
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Hughes Tool Co
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    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/08Roller bits
    • E21B10/14Roller bits combined with non-rolling cutters other than of leading-portion type

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  • Prior art percussion bits can be classified into two categories: (1) the chisel type, and (2) the rolling cutter type.
  • the chisel type is the more prevalent of the two, its popularity being based primarily on its rugged construction, which is strikingly similar to that of the common chisel.
  • it In one of its simplest forms it is a single, massive piece of metal with wedged-shaped pieces of tungsten carbide secured to its lower end. There are usually modifications such as connecting means at its upper end and provisions for blasting the bottom of the hole with air. Basically, however, it is nothing more than a large chisel.
  • the disadvantage of the chisel type bit is its inability to hold gage, that is, it wears rapidly at its outer cutting surface. As a consequence, the diameter of the bit and the hole decrease as drilling progresses. This is permissible in mining operations such as blast hole drilling where the hole size is not particularly critical. In drilling oil and gas wells, however, the hole size must be approximately uniform so that casing of a selected size may be inserted and secured in the hole. Therefore, the chisel type bit is unsuitable for such drilling operations.
  • the second category of percussion bits is distinguished by the ability to hold gage.
  • These bits are usually similar to the one described in the US, patent issued to Morlan et al., No. 2,687,875. Wear is distributed over the large, rotating surfaces of the cutters, a feature that increases their life at all points, including the gage surfaces.
  • These bits were initially developed for drilling under a static load and have proved outstanding for that application. Unfor tunately, they do not have the rugged construction that characterizes the chisel type bit, a feature that is needed to withstand repeated impact loads.
  • the head sections which support the bearing spindles on which the cutters are mounted, are usually welded together and these welds crack easily under the high level cyclic loads of percussion drilling. Attempts have been made to adapt this bit type to percussion drilling by correcting this and other weaknesses, but success has been limited.
  • the object of this invention is to combine the advantages of the chisel type bit and the rolling cutter bit.
  • the invention consists of a solid, rugged bit body (similar to the chisel type bit) equipped with rolling cutters assembled in a unique manner so as to withstand the large, fluctuating loads of percussion drilling.
  • FIGURE 1 is a perspective view showing the invention in its assembled form.
  • FIGURE l-A illustrates in fragmentary perspective an alternate form of cutting structure on the bit body.
  • FIGURE 2 is a side elevational view of the bit body showing in detail its construction.
  • FIGURE 3 is a sectional view of the bit body taken as indicated by the lines and arrows 33 of FIGURE 2,
  • FIGURE 3-A is a fragmentary section showing an alternate bearing configuration.
  • FIGURE 3-B is a fragmentary section showing another alternate bearing configuration and also an alternate type of cutting structure on the cutters.
  • FIGURE 4 is a perspective view, partially in section, showing the preferred configuration of the cutter retaining ring.
  • the numeral 10 designates the body portion of the drill bit with cutting elements 11 formed on its lower end and connecting means 12 formed on its upper end.
  • Splined connectors are also common in percussion drilling but are not illustrated; any prior art connecting means may be used with the invention.
  • At least one but preferably a plurality of cutters 16 are mounted on hearing spindles 22, which protrude outwardly and upwardly in cantilever fashion (shown in FIGURES 2 and 3 but not visible in FIGURE 1), and are formed integrally with the lower portion of body 10.
  • a ring 14- having downwardly protruding skirts 15 is secured to the body 10.
  • the skirts 15 retain the cutters 13 on the bearing spindles 22, providing a simply constructed and strong structure that eliminates the need for welds.
  • FIGURE 1 and the broad description above disclose the basic concept of the invention and its salient features, but do not reveal the structural details that contribute so much to its strength.
  • the concept of a cutter retainer which consists of :a ring with protruding skirts permits, for example, the use of a unitizied bit body 10 that is made of a single, strong and massive piece of material.
  • FIGURES 2 and 3 The strong construction of the bit body is shown in FIGURES 2 and 3, where the numeral 16 represents a cylindrical surface on body 10 that confronts a matching surface 17 (see FIGURE 4) on the inside of ring 14.
  • a radially extending surface or shelf 18 intersects the cylindrical surface 16 to provide a positioning stop for the lower surface 30 of ring 14 that butts against shelf 18.
  • Extending downwardly from shelf 18 is a conical surface 19 that intersects a lower conical surface 35.
  • the conical shape of these surfaces is not essential but is merely a convenient Way to there the body metal outwardly and downwardly to provide strong support for cutting elements 11 and 2 7.
  • the shape of these surfaces is beneficial in providing additional space for the flushing fluid and cuttings as they move from the bore hole bottom upwardly along the exterior of the drill bit.
  • a flat and vertical surface 34 joins cylindrical surface 16 in such a manner that both surfaces appear as a line in FIGURE 3.
  • Flat surface 34 is required in this embodiment to provide clearance for the passage of skirts 15 by the bit body 10 during assembly. Obviously, if conical surface 19 were to extend uninterrupted around the bit body, the skirts 15 could not reach their final, intended position.
  • bearing metal of a similar nature is deposited in suit-able slots 38 on the surface of bearing spindle 22;.
  • a substantially l'lOi'lzontal surface in which are inserted a multiplicity of wear resistant insert-s 11 selected from the sintered metal carbides, preferably tungsten carbide. These inserts are spaced at different radial distances from the drill axis of rotation 26 except near the outer periphery of the bit where a plurality of outermost or heel inserts 27 are disposed to rotate at the corner of the bore hole.
  • a multiplicity of wear resistant insert-s 11 selected from the sintered metal carbides, preferably tungsten carbide.
  • the inserts 11 and 27 are preferably elongated and cylindrical, and are secured by well known means such as by interference fit or by one of the brazing techniques.
  • the heel inserts 27 are angularly disposed so that their buried ends lie within the bit body conical surface 35.
  • the inner inserts 11 are preferably aligned with their longitudinal axis parallel with the bit axis 26 so that the forces transferred through them are compressive and pass directly to the bottom of the drilled hole. Lands 42 are sometimes used (they are necessary only in rare instances) to give additional support to the inserts to prevent breakage.
  • Cutters 13 are mounted so that they cooperate with heel inserts 27 to disintegrate the corner of the bore hole. This feature is beneficial in protecting the heel inserts 27 from excessive wear. Furthermore, the heel inserts break up any rock teeth that tend to form on the bore hole bottom, thus keeping the cones from tracking, a condition that slows the penetration rate of the bit.
  • the tracking problem arises when the crests 39 on the teeth of each cutter fall in the indentations made on the bore hole bottom by the crests of other teeth. The indentations continue to grow deeper while the ridges between them grow higher. As the crests 39 of the teeth slide down these ridges, the teeth are worn by the abrasives in the earths formations.
  • the cutters 13 have webs 4t that connect the crest 39 of the teeth at their outer ends. This provides a large surface that may be covered with wear resistant material, such as tungsten carbide in a suitable binder, to prevent the cutters from wearing too quickly. It is usually best to provide relief slots 41 that permit cuttings to move away from the wall of the hole and also make a milling cutter of the outer portions of the cutters.
  • a central passage 24 is formed in the upper part of the bit body Iii. At least one passage 23 directs the fluid to the bore hole bottom where the cuttings are entrained and removed from the hole.
  • a plurality of passageways are used, at least some of which are angularly disposed, as are the passageways of FIGURE 1. This configuration is beneficial in blasting the corner of the hole with a high velocity stream of fluid that removes quickly the cuttings that tend to lie dormantly in this hard-to-reach area.
  • the interference ring 14 is illustrated in FIGURE 4 where the skirts 15 are shown, including the inner surfaces 43 that abut the ends 52 of bearing spindles 22 after assembly to retain cutters 13.
  • the cylindrical surface 17 of the ring is a few thousandths of an inch smaller in diameter (.003 inch interference on a cylindrical surface of 3 /8 diameter for a 6% inch diameter bit was found suitable) than the matching cylindrical surface 16 of the bit body 10.
  • guide means such as key seat 44 that confronts a matching protrusion on the bit body (not shown).
  • the inner surface 43 of ring 15 has a groove 45 filled with a good bearing metal such as silver, silver alloy, iron or cobalt based alloy.
  • the cutters 13 are generally pushed inwardly at the gage of the hole during drilling and this cocks them so that they contact deposit 37 on surface 32 of the bit body 10 and groove 45 of ring 14.
  • the unitized bit body 10 for example, is fabricated of only one massive piece of metal that offers durability to the bit.
  • the cutters secured to the body by novel means, provides resistance to gage wear.
  • the novel retaining means eliminates the need for welds.
  • FIG- URE LA illustrates a modification having chisel-like cutting elements 46 that are well known in the art.
  • This and other old art cutting structures are within the scope of the invention since the inventive concept encompasses a novel body construction and cone retaining means and is not limited to the cutting structures shown and described.
  • the bearings of spindles 22 and cutters 13 are preferably of the journal type as is shown in FIGURE 3, the invention is not limited to journal bearings, but encompasses all old art devices such as the roller bearing of FIGURE 3-A.
  • the spindle is designated by numeral 47, which has an annular groove 48 into which are inserted rollers 49.
  • Rolling cutter 50 is inserted over the rollers 49 and the interference ring is assembled so that skirt 51 confronts the end of spindle 47 to retain cutter 50 thereon.
  • This construction is not preferred, however, since the rollers 49 absorb energy during impact loading, thereby decreasing the efficiency of the bit.
  • FIGURE 3B is similar to FIGURE 3A in that it illustrates an anti-friction bearing consisting of balls 53 mounted in matching raceways in bearing spindle 47 and cutter 54.
  • Journal surface 55 in cutter 54 and surface 62 on bearing spindle 47 constitute a journal bearing that cooperates with the anti-friction bearing to support the various forces.
  • cutter 54 is assembled on bearing spindle 47, and then the balls 53 are inserted through drilled hole 63 in bearing spindle 47. Then a plug 56 is inserted into drilled hole 63 and the skirt 51 of the interference ring is assembled, retaining the plug 56 which in turn retains the balls 53 in their raceways.
  • the advantages of eliminating welds is achieved by the use of a ring with protruding skirts 51, and is thus within the inventive concept.
  • FIGURE 3-B Another modification of the invention is illustrated in FIGURE 3-B Where the cutter 54 is illustrated as having a plurality of wear resistant inserts 57. These inserts are generally cylindrical in cross-section and are secured by interference fit in matching, cylindrical holes in the cutter 54.
  • cutters l3 and inaaeaseo serts 11 and 27 of body It should be balanced and this depends to a large extent on the formations drilled. Tests on various granites, for examples, indicated that wear is better balanced by using milled cutters l3 and cylindrical inserts with blunt, protruding ends in the bit body it). When cutters with inserts, such as cutter 54 of FIGURE 3-B, were used, the cutters lasted much longer than the 5 cutting elements of the bit body. It is better design practice to balance the wear between the various parts and for this reason the milled cutters are preferred. It may prove economically feasible, however, to disassemble the bit on the drilling location and assemble the partially worn cutters on new bit bodies. If so, the inserts cutters 54 of FIGURE 3-B may prove to be the better of the two type illustrated.
  • Cutters 13 may be moved upwardly from the location shown in FIGURE 1 so that they merely ream the hole. Conversely, they can be moved downwardly so that cutter crests 39 and webs 40 cut a kerf on the bore hole bottom. In the latter arrangement the body inserts 11 cut only the resulting core, and heel inserts 27 may be eliminated.
  • the bit will rotate more consistently about longitudinal axis 26, whereas the use of only one cutter frequently causes the bit to rotate about an axis other than axis 26.
  • the use of more than two cutters produces results in this regard similar to the use of two cutters, and the decision to illustrate a two cutter design is prompted merely by the resulting simplification of construction.
  • the bearing spindles 22 have been described as being integral with bit body and this is indeed the preferred arrangement. Nevertheless, the spindles 22 can be made separately and inserted into the bit body 10 by interference fit or by other suitable means. Although this arrangement is undoubtedly weaker than the integral structure, the advantage of using the ring as a cutter retainer still obtains and thus this modification is within the inventive concept.
  • Ring 14 is preferably an interference ring, which encompasses rings secured to the bit body by such old art methods of assembly as the shrink fit and the press fit.
  • the ring 14- may be retained by the drill string member 58 of FIGURE 3.
  • the shoulder 59 of the drill collar 58 engages shoulders 6t) and 61 of ring 14 and bit body 10 during assembly and thereafter ring 14 cannot be removed without removing the drill collar.
  • the bit body ill of FIGURE 1 has been described as being flat or horizontal across its lower surface 20.
  • the invention is not limited to such constructions but encompasses rounded, concave, convex or stepped surfaces.
  • the flat configuration is thought best, however, and for that reason is illustrated in the drawing.
  • the invention has been described as one especially suitable for percussion drilling. Testing has in fact been restricted to percussion drilling because this is where most fatigue problems reside at present.
  • the invention nevertheless has utility as a drill bit suitable for conventional, rotary drilling. There are numerous drill bits that have a body portion and rolling cutters. None of them, how ever, have the novel structure of the present invention.
  • a rotary-percussion bit of the type having a solid massive body with an upper end adapted to be connected to a drill string member and a lower end extending diametrically substantially the full width of a borehole to be cut, there being fixed percussive cutting elements secured in and protruding downwardly from said lower end and disposed to cut a full borehole While the bit is rotated and subject to percussion during drilling, the improvement comprising at least one bearing spindle secured to said bit body and extending upwardly and outwardly therefrom with its outer end terminating unsecured in cantilever fashion, a rolling cutter rotatably mounted on said bearing spindle, said cutter being disposed to assist said percussive cutting elements.

Description

.J. L. KELLY, JR
SOLID HEAD ROTARY-PERGUSSION BIT WITH ROLLING GUTTERS V 2 Sheets-$heet 1 Aug. 30, 1966 Filed Jan. 10 1964 JOSEPH L. KELLY, JR.
INVENTOR.
ATTORNEY Aug. 30, 1966 J. 1.. KELLY, JR 3,
SOLID HEAD ROTARY-PERCUSSION BIT WITH ROLLING CUTTERS Filed Jan. 10, 1964 2 Sheets-Sheet 2 JOSEPH L. KELLY,, JR.
INVENTOR.
ATTORNEY FIGURE 4 United States Patent 3,269,46? SOLID HEAD RUTARY-PERCUSSIQN BIT WITH ROLLING QUTTERS Joseph L. Kelly, .112, Houston, Tex, assignor to Hughes Tool Company, Houston, Tex, a corporation of Delaware Filed Ian. 10, 1964, Ser. No. 336,942 1 Claim. (Cl. 175336) This invention relates generally to earth boring tools and in particular to a novel drill bit that is suitable for percussion drilling.
Prior art percussion bits can be classified into two categories: (1) the chisel type, and (2) the rolling cutter type.
The chisel type is the more prevalent of the two, its popularity being based primarily on its rugged construction, which is strikingly similar to that of the common chisel. In one of its simplest forms it is a single, massive piece of metal with wedged-shaped pieces of tungsten carbide secured to its lower end. There are usually modifications such as connecting means at its upper end and provisions for blasting the bottom of the hole with air. Basically, however, it is nothing more than a large chisel.
The disadvantage of the chisel type bit is its inability to hold gage, that is, it wears rapidly at its outer cutting surface. As a consequence, the diameter of the bit and the hole decrease as drilling progresses. This is permissible in mining operations such as blast hole drilling where the hole size is not particularly critical. In drilling oil and gas wells, however, the hole size must be approximately uniform so that casing of a selected size may be inserted and secured in the hole. Therefore, the chisel type bit is unsuitable for such drilling operations.
The second category of percussion bits, the rolling cutter type, is distinguished by the ability to hold gage. These bits are usually similar to the one described in the US, patent issued to Morlan et al., No. 2,687,875. Wear is distributed over the large, rotating surfaces of the cutters, a feature that increases their life at all points, including the gage surfaces. These bits were initially developed for drilling under a static load and have proved outstanding for that application. Unfor tunately, they do not have the rugged construction that characterizes the chisel type bit, a feature that is needed to withstand repeated impact loads. For example, the head sections, which support the bearing spindles on which the cutters are mounted, are usually welded together and these welds crack easily under the high level cyclic loads of percussion drilling. Attempts have been made to adapt this bit type to percussion drilling by correcting this and other weaknesses, but success has been limited.
The object of this invention is to combine the advantages of the chisel type bit and the rolling cutter bit. The invention consists of a solid, rugged bit body (similar to the chisel type bit) equipped with rolling cutters assembled in a unique manner so as to withstand the large, fluctuating loads of percussion drilling.
This and other objects will become apparent hereinafter and in the drawings in which:
FIGURE 1 is a perspective view showing the invention in its assembled form.
FIGURE l-A illustrates in fragmentary perspective an alternate form of cutting structure on the bit body.
FIGURE 2 is a side elevational view of the bit body showing in detail its construction.
FIGURE 3 is a sectional view of the bit body taken as indicated by the lines and arrows 33 of FIGURE 2,
Patented August 30, 1.966
with the addition of the assembled cutters, the ring and a drill string member.
FIGURE 3-A is a fragmentary section showing an alternate bearing configuration.
FIGURE 3-B is a fragmentary section showing another alternate bearing configuration and also an alternate type of cutting structure on the cutters.
FIGURE 4 is a perspective view, partially in section, showing the preferred configuration of the cutter retaining ring.
In describing the preferred embodiment of the invention, specific terminology is used to add clarity. The invention is not limited, however, by this specific terminology to the particular structure described, but encompasses all equivalent structures that function in a similar manner to accomplish a similar result.
Referring now to FIGURE 1 to give a broad description of the invention, the numeral 10 designates the body portion of the drill bit with cutting elements 11 formed on its lower end and connecting means 12 formed on its upper end. (Splined connectors are also common in percussion drilling but are not illustrated; any prior art connecting means may be used with the invention.) At least one but preferably a plurality of cutters 16 are mounted on hearing spindles 22, which protrude outwardly and upwardly in cantilever fashion (shown in FIGURES 2 and 3 but not visible in FIGURE 1), and are formed integrally with the lower portion of body 10. A ring 14- having downwardly protruding skirts 15 is secured to the body 10. The skirts 15 retain the cutters 13 on the bearing spindles 22, providing a simply constructed and strong structure that eliminates the need for welds.
FIGURE 1 and the broad description above disclose the basic concept of the invention and its salient features, but do not reveal the structural details that contribute so much to its strength. The concept of a cutter retainer which consists of :a ring with protruding skirts permits, for example, the use of a unitizied bit body 10 that is made of a single, strong and massive piece of material.
The strong construction of the bit body is shown in FIGURES 2 and 3, where the numeral 16 represents a cylindrical surface on body 10 that confronts a matching surface 17 (see FIGURE 4) on the inside of ring 14. A radially extending surface or shelf 18 intersects the cylindrical surface 16 to provide a positioning stop for the lower surface 30 of ring 14 that butts against shelf 18. Extending downwardly from shelf 18 is a conical surface 19 that intersects a lower conical surface 35. The conical shape of these surfaces is not essential but is merely a convenient Way to there the body metal outwardly and downwardly to provide strong support for cutting elements 11 and 2 7. Furthermore, the shape of these surfaces is beneficial in providing additional space for the flushing fluid and cuttings as they move from the bore hole bottom upwardly along the exterior of the drill bit.
A flat and vertical surface 34 joins cylindrical surface 16 in such a manner that both surfaces appear as a line in FIGURE 3. Flat surface 34 is required in this embodiment to provide clearance for the passage of skirts 15 by the bit body 10 during assembly. Obviously, if conical surface 19 were to extend uninterrupted around the bit body, the skirts 15 could not reach their final, intended position.
Cavities 21, defined by cylindrical surface 36 on one side and bearing spindle 22 on the other, are formed on opposite sides of the bit body Ill, providing space for cutters 13. A thrust surface 32 that matches an opposed surface on each cutter 13 is also formed on the body 10, preferably having a deposit 37 of suitable hearing metal. In addition, bearing metal of a similar nature is deposited in suit-able slots 38 on the surface of bearing spindle 22;.
Below the bearing spindles 22 is a substantially l'lOi'lzontal surface in which are inserted a multiplicity of wear resistant insert-s 11 selected from the sintered metal carbides, preferably tungsten carbide. These inserts are spaced at different radial distances from the drill axis of rotation 26 except near the outer periphery of the bit where a plurality of outermost or heel inserts 27 are disposed to rotate at the corner of the bore hole. Experience has shown that large amounts of energy are expended in drilling the corner of a bore hole; thus, more inserts are required at that location.
The inserts 11 and 27 are preferably elongated and cylindrical, and are secured by well known means such as by interference fit or by one of the brazing techniques. The heel inserts 27 are angularly disposed so that their buried ends lie within the bit body conical surface 35. The inner inserts 11 are preferably aligned with their longitudinal axis parallel with the bit axis 26 so that the forces transferred through them are compressive and pass directly to the bottom of the drilled hole. Lands 42 are sometimes used (they are necessary only in rare instances) to give additional support to the inserts to prevent breakage.
Cutters 13 are mounted so that they cooperate with heel inserts 27 to disintegrate the corner of the bore hole. This feature is beneficial in protecting the heel inserts 27 from excessive wear. Furthermore, the heel inserts break up any rock teeth that tend to form on the bore hole bottom, thus keeping the cones from tracking, a condition that slows the penetration rate of the bit. The tracking problem arises when the crests 39 on the teeth of each cutter fall in the indentations made on the bore hole bottom by the crests of other teeth. The indentations continue to grow deeper while the ridges between them grow higher. As the crests 39 of the teeth slide down these ridges, the teeth are worn by the abrasives in the earths formations. The heel inserts 27, by cooperating with the teeth of the cutters 13 and destroying the ridges as they form, tend to eliminate the tracking problem.
The cutters 13 have webs 4t that connect the crest 39 of the teeth at their outer ends. This provides a large surface that may be covered with wear resistant material, such as tungsten carbide in a suitable binder, to prevent the cutters from wearing too quickly. It is usually best to provide relief slots 41 that permit cuttings to move away from the wall of the hole and also make a milling cutter of the outer portions of the cutters.
Very few inserts 11 are required at the inner portions of the bit and they are disposed in body It) in almost a straight row. Obviously, excessive amounts of metal are undesirable on the bottom of the bit because room must be provided for the escape of cuttings from the bore hole bottom. For this reason the excess metal is removed by forming grooves 28 in an oblique fashion as is shown in FIGURES 1 and 2, perhaps more clearly in FIGURE 1.
To remove the cuttings from the bore hole bottom, a central passage 24 is formed in the upper part of the bit body Iii. At least one passage 23 directs the fluid to the bore hole bottom where the cuttings are entrained and removed from the hole. Preferably, a plurality of passageways are used, at least some of which are angularly disposed, as are the passageways of FIGURE 1. This configuration is beneficial in blasting the corner of the hole with a high velocity stream of fluid that removes quickly the cuttings that tend to lie dormantly in this hard-to-reach area.
The interference ring 14 is illustrated in FIGURE 4 where the skirts 15 are shown, including the inner surfaces 43 that abut the ends 52 of bearing spindles 22 after assembly to retain cutters 13. The cylindrical surface 17 of the ring is a few thousandths of an inch smaller in diameter (.003 inch interference on a cylindrical surface of 3 /8 diameter for a 6% inch diameter bit was found suitable) than the matching cylindrical surface 16 of the bit body 10. To prevent the ring 14 from rotating with respect to the bit body 1% during assembly, it is preferable to have guide means such as key seat 44 that confronts a matching protrusion on the bit body (not shown). The inner surface 43 of ring 15 has a groove 45 filled with a good bearing metal such as silver, silver alloy, iron or cobalt based alloy. The cutters 13 are generally pushed inwardly at the gage of the hole during drilling and this cocks them so that they contact deposit 37 on surface 32 of the bit body 10 and groove 45 of ring 14.
In View of the detailed description above, the numerous advantages of the invention should be apparent, espe' cially its simple and rugged construction. The unitized bit body 10, for example, is fabricated of only one massive piece of metal that offers durability to the bit. The cutters, secured to the body by novel means, provides resistance to gage wear. The novel retaining means eliminates the need for welds. Thus the invention combines the advantages of prior art bits and provides a long needed advance in the drilling art.
Various modifications to the structure will occur to those of average skill in the art, but particularly noteworthy is the fact that the invention is not limited to the cutting elements 11 and 27 shown in FIGURE 1. FIG- URE LA, for example, illustrates a modification having chisel-like cutting elements 46 that are well known in the art. This and other old art cutting structures are within the scope of the invention since the inventive concept encompasses a novel body construction and cone retaining means and is not limited to the cutting structures shown and described.
Although the bearings of spindles 22 and cutters 13 are preferably of the journal type as is shown in FIGURE 3, the invention is not limited to journal bearings, but encompasses all old art devices such as the roller bearing of FIGURE 3-A. Here the spindle is designated by numeral 47, which has an annular groove 48 into which are inserted rollers 49. Rolling cutter 50 is inserted over the rollers 49 and the interference ring is assembled so that skirt 51 confronts the end of spindle 47 to retain cutter 50 thereon. This construction is not preferred, however, since the rollers 49 absorb energy during impact loading, thereby decreasing the efficiency of the bit.
FIGURE 3B is similar to FIGURE 3A in that it illustrates an anti-friction bearing consisting of balls 53 mounted in matching raceways in bearing spindle 47 and cutter 54. Journal surface 55 in cutter 54 and surface 62 on bearing spindle 47 constitute a journal bearing that cooperates with the anti-friction bearing to support the various forces. In this embodiment cutter 54 is assembled on bearing spindle 47, and then the balls 53 are inserted through drilled hole 63 in bearing spindle 47. Then a plug 56 is inserted into drilled hole 63 and the skirt 51 of the interference ring is assembled, retaining the plug 56 which in turn retains the balls 53 in their raceways. In this embodiment the advantages of eliminating welds is achieved by the use of a ring with protruding skirts 51, and is thus within the inventive concept.
In view of the bearing modifications illustrated in FIG- URES 3-A and 3-B, it is apparent that many old art hearing structures are operable with the invention. Hence, the invention is not limited to the modifications illustrated; rather, the wide range of the applicability of the invention is shown thereby.
Another modification of the invention is illustrated in FIGURE 3-B Where the cutter 54 is illustrated as having a plurality of wear resistant inserts 57. These inserts are generally cylindrical in cross-section and are secured by interference fit in matching, cylindrical holes in the cutter 54.
One criterion for the selection of cutters is the type formation to be drilled. Wear of the cutters l3 and inaaeaseo serts 11 and 27 of body It) should be balanced and this depends to a large extent on the formations drilled. Tests on various granites, for examples, indicated that wear is better balanced by using milled cutters l3 and cylindrical inserts with blunt, protruding ends in the bit body it). When cutters with inserts, such as cutter 54 of FIGURE 3-B, were used, the cutters lasted much longer than the 5 cutting elements of the bit body. It is better design practice to balance the wear between the various parts and for this reason the milled cutters are preferred. It may prove economically feasible, however, to disassemble the bit on the drilling location and assemble the partially worn cutters on new bit bodies. If so, the inserts cutters 54 of FIGURE 3-B may prove to be the better of the two type illustrated.
The number of bearing spindles and cutters and their location with respect to the rest of the drill is not especially critical as far as the basic concept is concerned. Cutters 13 may be moved upwardly from the location shown in FIGURE 1 so that they merely ream the hole. Conversely, they can be moved downwardly so that cutter crests 39 and webs 40 cut a kerf on the bore hole bottom. In the latter arrangement the body inserts 11 cut only the resulting core, and heel inserts 27 may be eliminated.
As is clearly illustrated, it is preferable to have at least two cutters, although one cutter may be used. When using two oppositely located cutters, the bit will rotate more consistently about longitudinal axis 26, whereas the use of only one cutter frequently causes the bit to rotate about an axis other than axis 26. The use of more than two cutters produces results in this regard similar to the use of two cutters, and the decision to illustrate a two cutter design is prompted merely by the resulting simplification of construction.
The bearing spindles 22 have been described as being integral with bit body and this is indeed the preferred arrangement. Nevertheless, the spindles 22 can be made separately and inserted into the bit body 10 by interference fit or by other suitable means. Although this arrangement is undoubtedly weaker than the integral structure, the advantage of using the ring as a cutter retainer still obtains and thus this modification is within the inventive concept.
Ring 14 is preferably an interference ring, which encompasses rings secured to the bit body by such old art methods of assembly as the shrink fit and the press fit. On the other hand the ring 14- may be retained by the drill string member 58 of FIGURE 3. In this embodiment the shoulder 59 of the drill collar 58 engages shoulders 6t) and 61 of ring 14 and bit body 10 during assembly and thereafter ring 14 cannot be removed without removing the drill collar.
iii
The bit body ill of FIGURE 1 has been described as being flat or horizontal across its lower surface 20. The invention, however, is not limited to such constructions but encompasses rounded, concave, convex or stepped surfaces. The flat configuration is thought best, however, and for that reason is illustrated in the drawing.
Considerable geometrical details have been recited in describing the preferred embodiment, especially in relation to the bit body 1d. These details should not be taken as limitating the invention, for there are perhaps infinite geometrical variations that are possible. These details are given to enable those in the art to understand how the invention is preferably made.
The invention has been described as one especially suitable for percussion drilling. Testing has in fact been restricted to percussion drilling because this is where most fatigue problems reside at present. The invention nevertheless has utility as a drill bit suitable for conventional, rotary drilling. There are numerous drill bits that have a body portion and rolling cutters. None of them, how ever, have the novel structure of the present invention.
I claim:
In a rotary-percussion bit of the type having a solid massive body with an upper end adapted to be connected to a drill string member and a lower end extending diametrically substantially the full width of a borehole to be cut, there being fixed percussive cutting elements secured in and protruding downwardly from said lower end and disposed to cut a full borehole While the bit is rotated and subject to percussion during drilling, the improvement comprising at least one bearing spindle secured to said bit body and extending upwardly and outwardly therefrom with its outer end terminating unsecured in cantilever fashion, a rolling cutter rotatably mounted on said bearing spindle, said cutter being disposed to assist said percussive cutting elements. In cutting the outer portion of the borehole formed by said elements during drilling, and a ring member secured to the bit body above said bearing spindle, said ring having a downwardly extending skirt which confronts the unsupported end of the bearing spindle to retain the cutter thereon.
References Cited by the Examiner UNITED STATES PATENTS 1,816,568 7/1931 Carlson l336 2,166,462 7/1939 Catland l75333 2,320,136 5/1943 Kammerer -333 2,851,253 9/1958 Boice 175-355 JACOB L. NACKENOFF, Primary Examiner.
CHARLES E. OCONNELL, Examiner.
N. C. BYERS, Assistant Examiner.
US336942A 1964-01-10 1964-01-10 Solid head rotary-percussion bit with rolling cutters Expired - Lifetime US3269469A (en)

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Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3357507A (en) * 1965-10-24 1967-12-12 Mission Mfg Co Percussion bit
US3862665A (en) * 1973-10-11 1975-01-28 Reed Tool Co Scrape-type cutter for drill bits
US4006788A (en) * 1975-06-11 1977-02-08 Smith International, Inc. Diamond cutter rock bit with penetration limiting
DE2633779A1 (en) * 1976-07-28 1978-02-02 Richard Karnebogen DRILL BIT FOR HITTING ROCK DRILLING MACHINES
DE2655488A1 (en) * 1976-12-08 1978-06-15 Smith International Rock drill diamond and carbide cutting tip arrangement - has different cutting zones to ensure fine grinding of cut material
US4285409A (en) * 1979-06-28 1981-08-25 Smith International, Inc. Two cone bit with extended diamond cutters
US4716976A (en) * 1986-10-28 1988-01-05 Kennametal Inc. Rotary percussion drill bit
US20080011519A1 (en) * 2006-07-17 2008-01-17 Baker Hughes Incorporated Cemented tungsten carbide rock bit cone
US20080202814A1 (en) * 2007-02-23 2008-08-28 Lyons Nicholas J Earth-boring tools and cutter assemblies having a cutting element co-sintered with a cone structure, methods of using the same
US20080264695A1 (en) * 2007-04-05 2008-10-30 Baker Hughes Incorporated Hybrid Drill Bit and Method of Drilling
US20080296068A1 (en) * 2007-04-05 2008-12-04 Baker Hughes Incorporated Hybrid drill bit with fixed cutters as the sole cutting elements in the axial center of the drill bit
US20090126998A1 (en) * 2007-11-16 2009-05-21 Zahradnik Anton F Hybrid drill bit and design method
US20090272582A1 (en) * 2008-05-02 2009-11-05 Baker Hughes Incorporated Modular hybrid drill bit
US20090308662A1 (en) * 2008-06-11 2009-12-17 Lyons Nicholas J Method of selectively adapting material properties across a rock bit cone
US20100018777A1 (en) * 2008-07-25 2010-01-28 Rudolf Carl Pessier Dynamically stable hybrid drill bit
US20100025119A1 (en) * 2007-04-05 2010-02-04 Baker Hughes Incorporated Hybrid drill bit and method of using tsp or mosaic cutters on a hybrid bit
US20100106285A1 (en) * 2008-10-29 2010-04-29 Massey Alan J Method and apparatus for robotic welding of drill bits
US20100104736A1 (en) * 2008-10-23 2010-04-29 Baker Hughes Incorporated Method and apparatus for automated application of hardfacing material to drill bits
US20100159157A1 (en) * 2008-10-23 2010-06-24 Stevens John H Robotically applied hardfacing with pre-heat
US20100155145A1 (en) * 2008-12-19 2010-06-24 Rudolf Carl Pessier Hybrid drill bit with secondary backup cutters positioned with high side rake angles
US20100155146A1 (en) * 2008-12-19 2010-06-24 Baker Hughes Incorporated Hybrid drill bit with high pilot-to-journal diameter ratio
US20100181292A1 (en) * 2008-12-31 2010-07-22 Baker Hughes Incorporated Method and apparatus for automated application of hardfacing material to rolling cutters of hybrid-type earth boring drill bits, hybrid drill bits comprising such hardfaced steel-toothed cutting elements, and methods of use thereof
US20100181116A1 (en) * 2009-01-16 2010-07-22 Baker Hughes Incororated Impregnated drill bit with diamond pins
US20100224417A1 (en) * 2009-03-03 2010-09-09 Baker Hughes Incorporated Hybrid drill bit with high bearing pin angles
US20100270085A1 (en) * 2009-04-28 2010-10-28 Baker Hughes Incorporated Adaptive control concept for hybrid pdc/roller cone bits
US20100288561A1 (en) * 2009-05-13 2010-11-18 Baker Hughes Incorporated Hybrid drill bit
US20100320001A1 (en) * 2009-06-18 2010-12-23 Baker Hughes Incorporated Hybrid bit with variable exposure
US20110079441A1 (en) * 2009-10-06 2011-04-07 Baker Hughes Incorporated Hole opener with hybrid reaming section
US20110079444A1 (en) * 2009-09-16 2011-04-07 Baker Hughes Incorporated External, Divorced PDC Bearing Assemblies for Hybrid Drill Bits
US20110079443A1 (en) * 2009-10-06 2011-04-07 Baker Hughes Incorporated Hole opener with hybrid reaming section
US8950514B2 (en) 2010-06-29 2015-02-10 Baker Hughes Incorporated Drill bits with anti-tracking features
US8978786B2 (en) 2010-11-04 2015-03-17 Baker Hughes Incorporated System and method for adjusting roller cone profile on hybrid bit
US9353575B2 (en) 2011-11-15 2016-05-31 Baker Hughes Incorporated Hybrid drill bits having increased drilling efficiency
US9476259B2 (en) 2008-05-02 2016-10-25 Baker Hughes Incorporated System and method for leg retention on hybrid bits
US9782857B2 (en) 2011-02-11 2017-10-10 Baker Hughes Incorporated Hybrid drill bit having increased service life
US10107039B2 (en) 2014-05-23 2018-10-23 Baker Hughes Incorporated Hybrid bit with mechanically attached roller cone elements
US10557311B2 (en) 2015-07-17 2020-02-11 Halliburton Energy Services, Inc. Hybrid drill bit with counter-rotation cutters in center
US11428050B2 (en) 2014-10-20 2022-08-30 Baker Hughes Holdings Llc Reverse circulation hybrid bit

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US2166462A (en) * 1938-05-02 1939-07-18 Globe Oil Tools Co Core drill head
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US1816568A (en) * 1929-06-05 1931-07-28 Reed Roller Bit Co Drill bit
US2166462A (en) * 1938-05-02 1939-07-18 Globe Oil Tools Co Core drill head
US2320136A (en) * 1940-09-30 1943-05-25 Archer W Kammerer Well drilling bit
US2851253A (en) * 1954-04-27 1958-09-09 Reed Roller Bit Co Drill bit

Cited By (70)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3357507A (en) * 1965-10-24 1967-12-12 Mission Mfg Co Percussion bit
US3862665A (en) * 1973-10-11 1975-01-28 Reed Tool Co Scrape-type cutter for drill bits
US4006788A (en) * 1975-06-11 1977-02-08 Smith International, Inc. Diamond cutter rock bit with penetration limiting
DE2633779A1 (en) * 1976-07-28 1978-02-02 Richard Karnebogen DRILL BIT FOR HITTING ROCK DRILLING MACHINES
DE2655488A1 (en) * 1976-12-08 1978-06-15 Smith International Rock drill diamond and carbide cutting tip arrangement - has different cutting zones to ensure fine grinding of cut material
US4285409A (en) * 1979-06-28 1981-08-25 Smith International, Inc. Two cone bit with extended diamond cutters
US4716976A (en) * 1986-10-28 1988-01-05 Kennametal Inc. Rotary percussion drill bit
US20080011519A1 (en) * 2006-07-17 2008-01-17 Baker Hughes Incorporated Cemented tungsten carbide rock bit cone
US20080202814A1 (en) * 2007-02-23 2008-08-28 Lyons Nicholas J Earth-boring tools and cutter assemblies having a cutting element co-sintered with a cone structure, methods of using the same
US20080296068A1 (en) * 2007-04-05 2008-12-04 Baker Hughes Incorporated Hybrid drill bit with fixed cutters as the sole cutting elements in the axial center of the drill bit
US7845435B2 (en) 2007-04-05 2010-12-07 Baker Hughes Incorporated Hybrid drill bit and method of drilling
US7841426B2 (en) 2007-04-05 2010-11-30 Baker Hughes Incorporated Hybrid drill bit with fixed cutters as the sole cutting elements in the axial center of the drill bit
US20080264695A1 (en) * 2007-04-05 2008-10-30 Baker Hughes Incorporated Hybrid Drill Bit and Method of Drilling
US20100025119A1 (en) * 2007-04-05 2010-02-04 Baker Hughes Incorporated Hybrid drill bit and method of using tsp or mosaic cutters on a hybrid bit
US20090126998A1 (en) * 2007-11-16 2009-05-21 Zahradnik Anton F Hybrid drill bit and design method
US10316589B2 (en) 2007-11-16 2019-06-11 Baker Hughes, A Ge Company, Llc Hybrid drill bit and design method
US10871036B2 (en) 2007-11-16 2020-12-22 Baker Hughes, A Ge Company, Llc Hybrid drill bit and design method
US8678111B2 (en) 2007-11-16 2014-03-25 Baker Hughes Incorporated Hybrid drill bit and design method
US8356398B2 (en) 2008-05-02 2013-01-22 Baker Hughes Incorporated Modular hybrid drill bit
US20110120269A1 (en) * 2008-05-02 2011-05-26 Baker Hughes Incorporated Modular hybrid drill bit
US20090272582A1 (en) * 2008-05-02 2009-11-05 Baker Hughes Incorporated Modular hybrid drill bit
US9476259B2 (en) 2008-05-02 2016-10-25 Baker Hughes Incorporated System and method for leg retention on hybrid bits
US20090308662A1 (en) * 2008-06-11 2009-12-17 Lyons Nicholas J Method of selectively adapting material properties across a rock bit cone
US7819208B2 (en) 2008-07-25 2010-10-26 Baker Hughes Incorporated Dynamically stable hybrid drill bit
US20100018777A1 (en) * 2008-07-25 2010-01-28 Rudolf Carl Pessier Dynamically stable hybrid drill bit
US9439277B2 (en) 2008-10-23 2016-09-06 Baker Hughes Incorporated Robotically applied hardfacing with pre-heat
US8969754B2 (en) 2008-10-23 2015-03-03 Baker Hughes Incorporated Methods for automated application of hardfacing material to drill bits
US9580788B2 (en) 2008-10-23 2017-02-28 Baker Hughes Incorporated Methods for automated deposition of hardfacing material on earth-boring tools and related systems
US20100159157A1 (en) * 2008-10-23 2010-06-24 Stevens John H Robotically applied hardfacing with pre-heat
US20100104736A1 (en) * 2008-10-23 2010-04-29 Baker Hughes Incorporated Method and apparatus for automated application of hardfacing material to drill bits
US8450637B2 (en) 2008-10-23 2013-05-28 Baker Hughes Incorporated Apparatus for automated application of hardfacing material to drill bits
US8948917B2 (en) 2008-10-29 2015-02-03 Baker Hughes Incorporated Systems and methods for robotic welding of drill bits
US20100106285A1 (en) * 2008-10-29 2010-04-29 Massey Alan J Method and apparatus for robotic welding of drill bits
US8047307B2 (en) 2008-12-19 2011-11-01 Baker Hughes Incorporated Hybrid drill bit with secondary backup cutters positioned with high side rake angles
US20100155146A1 (en) * 2008-12-19 2010-06-24 Baker Hughes Incorporated Hybrid drill bit with high pilot-to-journal diameter ratio
US20100155145A1 (en) * 2008-12-19 2010-06-24 Rudolf Carl Pessier Hybrid drill bit with secondary backup cutters positioned with high side rake angles
US8471182B2 (en) 2008-12-31 2013-06-25 Baker Hughes Incorporated Method and apparatus for automated application of hardfacing material to rolling cutters of hybrid-type earth boring drill bits, hybrid drill bits comprising such hardfaced steel-toothed cutting elements, and methods of use thereof
US20100181292A1 (en) * 2008-12-31 2010-07-22 Baker Hughes Incorporated Method and apparatus for automated application of hardfacing material to rolling cutters of hybrid-type earth boring drill bits, hybrid drill bits comprising such hardfaced steel-toothed cutting elements, and methods of use thereof
US20100181116A1 (en) * 2009-01-16 2010-07-22 Baker Hughes Incororated Impregnated drill bit with diamond pins
US8141664B2 (en) * 2009-03-03 2012-03-27 Baker Hughes Incorporated Hybrid drill bit with high bearing pin angles
US20100224417A1 (en) * 2009-03-03 2010-09-09 Baker Hughes Incorporated Hybrid drill bit with high bearing pin angles
US20100270085A1 (en) * 2009-04-28 2010-10-28 Baker Hughes Incorporated Adaptive control concept for hybrid pdc/roller cone bits
US8056651B2 (en) 2009-04-28 2011-11-15 Baker Hughes Incorporated Adaptive control concept for hybrid PDC/roller cone bits
US9670736B2 (en) 2009-05-13 2017-06-06 Baker Hughes Incorporated Hybrid drill bit
US8459378B2 (en) 2009-05-13 2013-06-11 Baker Hughes Incorporated Hybrid drill bit
US20100288561A1 (en) * 2009-05-13 2010-11-18 Baker Hughes Incorporated Hybrid drill bit
US8336646B2 (en) 2009-06-18 2012-12-25 Baker Hughes Incorporated Hybrid bit with variable exposure
US8157026B2 (en) 2009-06-18 2012-04-17 Baker Hughes Incorporated Hybrid bit with variable exposure
US20100320001A1 (en) * 2009-06-18 2010-12-23 Baker Hughes Incorporated Hybrid bit with variable exposure
US9982488B2 (en) 2009-09-16 2018-05-29 Baker Hughes Incorporated External, divorced PDC bearing assemblies for hybrid drill bits
US9004198B2 (en) 2009-09-16 2015-04-14 Baker Hughes Incorporated External, divorced PDC bearing assemblies for hybrid drill bits
US9556681B2 (en) 2009-09-16 2017-01-31 Baker Hughes Incorporated External, divorced PDC bearing assemblies for hybrid drill bits
US20110079444A1 (en) * 2009-09-16 2011-04-07 Baker Hughes Incorporated External, Divorced PDC Bearing Assemblies for Hybrid Drill Bits
US8191635B2 (en) 2009-10-06 2012-06-05 Baker Hughes Incorporated Hole opener with hybrid reaming section
US20110079440A1 (en) * 2009-10-06 2011-04-07 Baker Hughes Incorporated Hole opener with hybrid reaming section
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US20110079443A1 (en) * 2009-10-06 2011-04-07 Baker Hughes Incorporated Hole opener with hybrid reaming section
US9657527B2 (en) 2010-06-29 2017-05-23 Baker Hughes Incorporated Drill bits with anti-tracking features
US8950514B2 (en) 2010-06-29 2015-02-10 Baker Hughes Incorporated Drill bits with anti-tracking features
US8978786B2 (en) 2010-11-04 2015-03-17 Baker Hughes Incorporated System and method for adjusting roller cone profile on hybrid bit
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US10132122B2 (en) 2011-02-11 2018-11-20 Baker Hughes Incorporated Earth-boring rotary tools having fixed blades and rolling cutter legs, and methods of forming same
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US10072462B2 (en) 2011-11-15 2018-09-11 Baker Hughes Incorporated Hybrid drill bits
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US10107039B2 (en) 2014-05-23 2018-10-23 Baker Hughes Incorporated Hybrid bit with mechanically attached roller cone elements
US11428050B2 (en) 2014-10-20 2022-08-30 Baker Hughes Holdings Llc Reverse circulation hybrid bit
US10557311B2 (en) 2015-07-17 2020-02-11 Halliburton Energy Services, Inc. Hybrid drill bit with counter-rotation cutters in center

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