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Publication numberUS3137355 A
Publication typeGrant
Publication dateJun 16, 1964
Filing dateMay 31, 1962
Priority dateMay 31, 1962
Publication numberUS 3137355 A, US 3137355A, US-A-3137355, US3137355 A, US3137355A
InventorsSchumacher Jr Percy W
Original AssigneeReed Roller Bit Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Insert bit structure
US 3137355 A
Images(2)
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Description  (OCR text may contain errors)

June 16, 1964 P. W. SCHUMACHER, JR

INSERT BIT STRUCTURE 2 Sheets-Sheet 1 Filed May 31, 1962 I NVEN TOR. M BY g 5.41% 7h, g

A I TO/PW VJ P. w. SCHUMACHERQJR 3,137,355

June 16, 1964 INSERT BIT STRUCTURE 2 Sheets-Sheet 2 Filed May 31, 1962 P. W. Jc/7u/27ac/2er I INVENTOR.

Unitad Slams PatdI O 7 3,137,355 INSERT BIT STRUCTUR Percy W. Schumacher, Jr.,- Houston, Tex., assignor t Reed Roller Bit Company, Houston, Tex., a corporation of Texas 1 Filed May 31, 1962, Ser. No. 199,074 Claims. (Cl.- 175-374) This invention relates generally to roller cutter type earth boring drills, and more particularly to the cutters used on such drills.

In the drilling of wells with roller type drill bits, the bit is connected to the lower end of a drill stem which is lowered and rotated to cause the cutters to roll upon the bottom of the borehole to cut or crush the formation being encountered. A drilling fluid, such as mud or air, is pumped downwardly through the drill stem and bit, and rises in the space between the drill stem and the wall of the hole to the surface of the earth, to remove cuttings produced by the drilling operation.

The roller cutters to which the present invention relates are those in which formation crushing inserts of hard metal, such as sintered tungsten carbide, are mounted in steel rollers.

The general object of this invention is to so combine the sintered tungsten carbide insert and the steel of the roller that the steel will provide a strong support for the insert and at the same time permit maximum penetration of the formation by the insert, and also free movement of the cuttings away from the insert.

Another object is to provide such a cutter in which the insert is mounted in a frusto-conical boss so that there will be a minimum of steel adjacent the outer portion of the insert, and streamline surfaces surrounding the insert, to the end that the drilling fluid may quickly remove the cuttings without premature erosion of the boss, as the insert efl'iciently penetrates the formation.

A further object is to provide such a boss having a relatively thin outer portion so that it is expansible for the reception of the insert.

Other objects will become apparent from the following description and accompanying drawings, in which:

FIGURE 1 is a bottom plan view of a drill bit employing the invention.

FIGURE 2 is a longitudinal sectional view, partly in elevation, taken along line 2-2 in FIGURE 1.

FIGURE 3 is an enlarged fragmentary view taken along line 33 in FIGURE 2.

FIGURE4 is a plan view of the roller cutting portion shown in FIGURE 3.

In the drawings, a well drill is shown generally at 1 comprising a bit head 2 having a hollow threaded shank 3 adapted to be connected to the lower end of a drill stem (not shown). A drilling fluid is circulated downwardly through the drill stem into a chamber 4, and issues through passageways 5 to the exterior of the bit to wash the cuttings and detritus from the bottom of the hole.

Referring to FIGURES 1 and 2, the drill bit 1 may employ approximately conical shaped roller cutters 6, 7 and 8. The bit head 2 has a downwardly extending leg 9 and a shaft 10 projecting downwardly and inwardly from the leg 9. The cutter 6 is rotatably mounted on the shaft 10 on ball bearings 11 and roller bearings 12. The ball bearings 11 may be inserted in place through a bore I 3,137,355 Patented June 16, I964 metal inserts 18'may be inserted into the gage face 19 of 1 the cutter-6 to assist in maintaining the gage of the bore-' hole as drilling progresses.

The'bosses 17 have a socket 20 drilled or otherwise provided in said bosses. A wear resistant insert 21tis preferably secured in the socket 20 by pressing the insert 21 into said socket which may be slightly smaller than the outside diameter of the insert. The relatively thin wall of the outer portion of the boss 17 will readily permit such insertion.

Referring to FIGURES 3 and 4, the frusto-conical boss 17 extends radially outwardly from the surface 16 of the cutter 6. Since the boss 17 is frusto-conical in shape, the insert 21 is uniformly maintained therein since a plane passed through the boss 17 normal to the axis of the insert 21 would result in a section wherein the cutter material of the boss 17 has a uniform section surrounding the insert thereby effecting a more uniform retention of the insert. 7

As can best be seen in FIGURE 4, the upper surface 22 of the boss 17 shows such uniform surrounding cutter material. The outside diameter of the outer end of the boss 17 is approximately one-third larger than the diameter of the insert 21. Thus as drilling progresses, the area i 22 presents a relatively small amount of steel to contact the formation being drilled so that deeper penetration of the sintered tungsten carbide insert 21 into the formation is afforded. p I

In certain formations, it may be desired to employ the frusto-conical bosses on the intermediate areas of the drill bit rollers only, but it is apparent that, depending on the formation being encountered, various arrangements of such conical bosses may be employed.

Since the boss 17 and its attendant insert 21 project a substantially from the surface 16 of the cutter 6 to provide streamline surfaces, it will be apparent that the drilling fluid issuing from the passageways 5 may more easily circulate away formation cuttings from thebottom of the borehole and from the areas around the cutters, and that premature erosion of'the bosses is prevented.

Thus the invention provides a structure wherein hard metal inserts may be placed in frusto-conical shaped,

bosses to provide a uniform support for the insert, and a minimum amount of boss surface surrounding the insert to permit deeper insert penetration into the formation to effect a higher drilling rate.

a conical cutting tip pressed into each said socket and into said body and extending outwardly from said flat circular surface.

2. The roller cutter structure as defined in claim 1 in which the outside diameter of the outer end of each boss is approximately one-third larger than the diameter of the insert.

3. The cutter structure as defined in claim 1 in which the roller cutter is a conical roller cutter. 7

4. The cutter structure as defined in claim 1 in which the roller cutter is a conical roller cutter and in which the outside diameter of the outerend of each boss is approximately one-third larger than the diameter of the insert. I i

5. A rotary well drill comprisinga head having inwardly and downwardly extending shafts on the bottom portion thereof, approximately conical roller cutters rotatably mounted on said shafts, each of the cutters comprising a body portion having a row of'frusto-conical bosses integral therewith and disposed therearound, eachboss terminating outwardly in a flat circular surface, each boss having a socket extending through said boss into said body portion, and a tungsten carbide Wear-resistant insert substantially cylindrical in its shank part and prov vided with a conical cutting tip pressed into each said socket and into said body and extending outwardly from said flat circular surface.

References Cited in the file of this patent Talbert et al.1 June 27, 1961 T

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1885085 *Nov 26, 1930Oct 25, 1932Dalzen William FRock drill
US2121202 *Mar 19, 1935Jun 21, 1938Killgore Robert JRotary bit
US2168060 *Feb 5, 1938Aug 1, 1939Globe Oil Tools CoMethod of making cutters for well drilling tools
US2244617 *Jan 14, 1939Jun 3, 1941Nat Tool CompanyRoller bit
US2990025 *Jun 16, 1958Jun 27, 1961Dresser IndBit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3223188 *Oct 26, 1962Dec 14, 1965Chicago Pneumatic Tool CoRoller cone rock bit
US3452831 *Sep 20, 1967Jul 1, 1969Beyer Leaman RexRotary reaming and drilling bit
US3495668 *Jul 5, 1968Feb 17, 1970Murphy Ind Inc G WDrill bit
US3696876 *Mar 15, 1971Oct 10, 1972Dresser IndSoft formation insert bits
US5131480 *Jul 30, 1991Jul 21, 1992Smith International, Inc.Rotary cone milled tooth bit with heel row cutter inserts
US5145016 *Jan 30, 1991Sep 8, 1992Rock Bit International, Inc.Rock bit with reaming rows
US5287936 *Jan 31, 1992Feb 22, 1994Baker Hughes IncorporatedRolling cone bit with shear cutting gage
US5346026 *Dec 17, 1993Sep 13, 1994Baker Hughes IncorporatedRolling cone bit with shear cutting gage
US5421423 *Mar 22, 1994Jun 6, 1995Dresser Industries, Inc.Rotary cone drill bit with improved cutter insert
US5467836 *Sep 2, 1994Nov 21, 1995Baker Hughes IncorporatedFixed cutter bit with shear cutting gage
US5636700 *Jan 3, 1995Jun 10, 1997Dresser Industries, Inc.Roller cone rock bit having improved cutter gauge face surface compacts and a method of construction
US5695019 *Aug 23, 1995Dec 9, 1997Dresser Industries, Inc.Rotary cone drill bit with truncated rolling cone cutters and dome area cutter inserts
US5709278 *Jan 22, 1996Jan 20, 1998Dresser Industries, Inc.Rotary cone drill bit with contoured inserts and compacts
US5722497 *Mar 21, 1996Mar 3, 1998Dresser Industries, Inc.Roller cone gage surface cutting elements with multiple ultra hard cutting surfaces
US5755301 *Aug 9, 1996May 26, 1998Dresser Industries, Inc.Inserts and compacts with lead-in surface for enhanced retention
USRE29151 *Mar 27, 1975Mar 15, 1977Sun Oil CompanyRepulsing clays on drill bits
Classifications
U.S. Classification175/374, 175/426, 175/341
International ClassificationE21B10/46, E21B10/52
Cooperative ClassificationE21B10/52
European ClassificationE21B10/52