US1905165A - Disk bit - Google Patents

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April 1933- H. w. FLETCHER 1,905,165

' DISK BIT Filed March 17, 1930 2 4/10 lNkiA TOR BY 11m A TTORNEY i with the drill collar.

wardly extending legs 3 within which the cut- Patented Apr. 25, 1933 UNITED STATES.

PATEN :-ome;

HAROLD w. FLETCHER, or HOUSTON, TEXAS, imam; TO informs moor. comm, or

nous'ron, TEXAS, A coarioaanon or Texas Application filed March 17, 1980. Serial No. 436.335.

My invention relates to earth-boring drills employed in drilling deep wells and has particular application to drill bits of the socalled disk type in which the bore of the well is drilled by a plurality of disk-shaped cutters mounted rotatably upon a shaft supported in the drill head.

A difiiculty experienced with bits of the disk-type, which are intended particularly for drilling soft formations, is that the disks may easily become clogged with disintegrated material which is not carried away from the drill head sufliciently, thus preventing the rotation of the cutters.

It is an object of my invention to provide a drill bit having disk-shaped cutters thereon, said cutters being so formed as to engage the bottom of the hole so as to obtain suflicient traction thereon to cause them to rotate free- It is also an object to so construct the cutters that the flushing fluid maybe employed in rotating the cutters to clear them of material tending to clog thereon.

I also desire to construct the cutters so as to protect the shaft upon which the cutters are mounted so as to thereby prevent exces- F i 2 is a central vertical section throughv the rill taken at right angles to the view' shown in Fig. 1.

Fig. 3 is a bottom plan view of the drill 1 head with the cutters thereon.

In thedrawing I have illustrated my cut ters as mounted upon a. cylindrical head 1- having a threaded shank 2 for engagement- There are'two downflushing fluid to clear'the blades ofmud or material tending to clog the cutters. When ter shaft 4 is mounted to support the diskshaped drill cutters 5. There is a central lon 'tudinal channel 6 through the axis of the drifi to accommodate the flushing water which is discharged directly downward upon the disks.

The cuttershaft 4 shown as being drical shaft extending diametrically o the head and supported at each end in openings 7 V in the legs of the bit. The ends of said openings 7 are countersunk at 8 to receive a washer 9 andthe end of the shaft is reduced in :diameteratlO to extend through thewasher9 and the end of the reduced portion is upset or riveted at 11 against the washer so. asito lock i the shaft securely in position after the cutters have been placedthereon. When this shaft is to be removed the .upset end llof the shaft is chiselcdofl and the shaft removed;

; The cutters5 are disk-shaped,having i outer faces flattened-at 12 to, engage with the bearing washer 18 adjacent theleg; Beyond the'flattened portion the'cutter. is beveled at 13 soas to form a sharp cutting ed e 14 presented inwardly. The inner sideo eachcutter has a hub.15 extendin inwardly to a point spaced-slightly from t e hub of the adjacentcutter. This hub furnishes a bearing surface for the cutter and protects theshafti 4 from wear, due to the discharge of flushing fluid through the channel.6.. a

To provide for suflicient traction to cause a positive rotation of the cutters and also to allow the flushing waterto assist in-the rotation of the cutters, I form, on the inner ,faces of each cutter,-va-nes or webs 16, which, as shown :in Fig. 2, are tangential to the hub and are inclmed .fromthe end of said hub inwardly to the face ofthe-disk and tenni- 'nateon the face of the disk at a point spaced as seen in Fig. 2..

slightly from the margin, These. vanes or blades on the disksieng e with: the coral? which forms between the cutters on thebottom of the hole, and contact therewith assure sufiicient .tractlonto cause the cutters to positively rotate, The;

core coming in contact with broken up and disintegrated.

thesevanes is -These websare also ofuse in allowingthe it'is'noted that the bitisnot cutting in the usual manner due to the clog g of the cutters the bit may be raised 0 the bottom of the hole and the pumps used to flush the mud in a strong current downwardly through the channel 6 against the blades of the cutters. With the cutters ofi the bottom of the hole they are easily washed clear of material and the flushing water striking the webs 16 will cause the cutters to rotate and be uniformly clearedof material on all sides. The bit may then a ain be dropped upon the bottom of the ho f e and the drilling may continue. By the use of my particular construction of t e cutters I am enabled to secure sufiicient traction to cause rotation of the cut ters even though the cutters are not ofi'set one from the other, and, further, when the cutters tend to clog, the cutters may be easily I washed clear of material in the manner stated. By thus mounting the cutters in opposite relation 1 am enabled to'provide a simple. and economical structure which may be manufactured cheaply and which is strong 20 and sturdy and able to withstand the strains to which they are subjected. Also, even where the cutters are mounted directly opposite to each other, I am enabled to get rota- 'tion of the cutters. 26 What I claim as new is: f

1.- A drill head, a straight shaft sup orted thereon, disk-shaped cutters on said Is aft, means to space said cutters apart in opposite relation on said shaft, and means on the in- 30 ner faces of said cutters adapted to beacted upon by flushing fluid to rotate said cutters for the urpose stated. 1 i 2. A diill head, a straight shaft su' ported thereon, disk-shaped cutters on said shaft,

- means to space said cutters apart in opposite relation on' said shaft, and webs on the inner' faces of said cutters to be enga ed by flushing fluid to rotate said cutters an allow said cuttersto be cleaned.

4o 3. A drill head, a straight shaft supported on the forward end thereof, a pair: of diskshaped cutters having a bearing thereon, a means to space said cutters apart, water passages in said head discharging on said outters, and webs formed on the inner faces of said disks tangential to the axis thereof and I positioned to be engaged by the flushing fluid to rotate the cutters.

4. A drill head, downwardly extending '50 legs thereon, a shaft supported in said legs, I

opposite disk-shaped cutters rotatable *on said shaft, hubs on said cutters spacing said cutters'apart, webs on said hubs and the disks 'of'said' cutters, said webs tapering in width 7 outwardly and tangential to the axis of the 1 cutters, and water passages in said head dischar 'ng on said webs, whereby said cutters are c eaned and the rotation thereof assisted.

In testimony whereof I hereunto afiix my o0 signature this 12th day of March, A. D. 1930.

HAROLD W. FLETCHER.

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