US2098758A - Roller bit - Google Patents

Description

Nov. 9, 1937. c. E. REED ROLLER BIT Original Filed Dec. 6, 1933 VW i 3rwentor CLARENCE E. REED.

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attorney Patented Nov. 9, 1937 UNITED STATES- ROLLER BIT Clarence E. Reed, Wichita, Kana, asaignor to Chicago Pneumatic Tool Company, New York, N. Y.,- a corporation of New Jersey Original hole. The features of the invention covered by this application comprise an arrangement of outlets at the upper end of an inverted V-shaped recess positioned to discharge flushing fluid both radially and tangentially with respect to a cutter mounted in the recess. The outlets may be formed in a renewable pipe or conduit which is shaped to provide the minimum friction with the water or other flushing fluid so as to reduce wear and thereby prolong the life of the conduit.

Other features and objects of the present invention will appear more clearly from the following description taken in connection with the accompanying drawing and appended claims.

In the drawing:

Fig. l is a sectional view of the lower end of a drill bit embodying the present invention, the section being taken in the plane of the cutter axes;

Fig. 2 is a bottom view of the flushing fluid conduit or wash pipe; and

Fig. 3 is another view of the wash pipe looking in the directions of the arrows in Fig. 2, the lower half of the pipe being shown in full lines and the upper half in a section taken along the line 3-3.

The illustrative embodiment of the invention comprises a bit head It having at its lower end an inverted V-shaped recess II, the walls of which flare downwardly and outwardly. A bore l2 centrally located in the bit head communicates with the recess II for a purpose hereinafter described. The walls of the recess H are cut away to provide seat recesses l3 on opposite sides of the axis of the bit. These seat recesses communicate with longitudinal bores l4. The seat recesses l3 and bores I4 are adapted to receive and support the upper ends of roller cutter carriers l6 and I1 respectively. Each carrier member comprises a shank l8 received within bore I4 and a base I9 seated within seat recess I3. Suitable means (not shown) are provided for holding the shank securely in place on the bit head. The method of securing the roller cutter unit to the bit head is similar to the arrangement shown in applicants prior Patent Re. 17,741, dated July 22, 1930, reference to which is made for a more comapplication December 6, 1933, Serial No.

Divided and this application May 5, 1936, Serial No. 77,902

plete disclosure of elements not fully illustrated in the drawing of this application.

The base I9 is provided with a depending por tion 20 from which a spindle 2| projects downwardly and inwardly towards the axis of the drill. The spindle and the base are preferably integral to insure adequate strength. An annular groove 22 surrounding the spindle 2| is formed in the base IS. A bushing 23 fits snugly around the spindle 2| and has, at one end, a flange 24 seated in the annular groove 22. The engagement between the flange 24 and the base plate I9 is efiective to resist thrusts exerted upon the bushing during the operation of the drill. This flange 24 also acts as a thrust shoulder for the roller cutter 26 loosely mounted on the bushing 23. The cut.- ter 23 is preferably of cylindrical shape and o'f such length that one end thereof is in the same plane as the free end of the bushing and spindle.I

In order to secure the cutter against removal from the bushing, the spindle 2| is provided with a threaded bore to receive the bolt or shaft29 which is provided with a cap 30 engaging the free end of the spindle, bushing and-cutter. The cap 30 cooperates with the thrust shoulder 24 to hold the cutter 26 against any axial or wabbling movement. I

The carrier member I! is similar in principle but different in proportions from the carrier member for the roller cutter unit previously described. It carries a spindle 3| adapted to support a bushing 32 and shaft 33 arranged similarly to the corresponding elements mounted on shaft 2|. Spindle 3| is longer than spindle 2| and has a greater included angle with respect to the axis of the bit. A plurality of roller cutters 34 and 35, separated by a spacing Washer 36, are mounted on the bushing 32. These cutters'are arranged to rotate on the bushing independently of each other. The base IQ of the carrier member I1 is cut away at 38 to permit the cutter 35 to extend further outwardly from the center of the hole.

The roller cutters are arranged to cut the entire area at the bottom of the hole within a circle extending slightly beyond the periphery of the bit head I. In the embodiment of the invention illustrated in the drawing each cutter operates over a different annular area and none of the cutters track each other. The central cutter 34 is so positioned that its inner end is close to the axis of the drill (indicated in broken lines in Fig. 1). On the opposite side of the axis and separated from the central cutter by an open space 40 is the side cutter 26 which traverses the outermost annular area or zone at the bottom of the hole. The formation underlying the space 40 is cut by the central cutter 34 and intermediate cutter 35. It will be apparent that more than two cutters could be employed for this purpose if desired.

Preferably, the two spindles 2| and BI are arranged with their axes in the same plane with each other and with the axis of the bit. This arrangement, however, is not essential, since the spindles may be disposed, for example, in planes 120 degrees apart and there may be more than two spindles.

The cutter units comprising the carrier members i 6 and ii are supported in the bit head independently of each other and either one may be removed and replaced as a unit without disturbing the other.

The invention also comprises novel means for distributing flushing fluid to the bottom of the hole and to the cutters. A renewable conduit or wash pipe.4l, shaped to flt the lower end of the bit head it) is provided with a cylindrical portion 42 received by the bore II. The extreme lower end of bore i2 is shaped to flt the conduit 4|. The pipe is held in place by suitable means such as a press fit. The lower end of the pipe or conduit is provided with flaring portions 43 and 44 which terminate in an integral flange or head 46.

Head 46 is provided with a plurality of outlets including outlets 48, 49 and 50 arranged in the plane of the spindles 2i and 3| which plane is transverse to the walls of the V-shaped recess ll. These openings are separated by ballles SI and 52 of acute angular shape whereby to divert the stream of water or other flushing fluid without materially reducing its velocity or causing undue wear on the pipe. The directions of the outlets 48, 49 and 50 are such that the water impinges directly against the top of each roller cutter. Other outlets 53 and 54, formed in the flaring portions 43 and 44 respectively, provide streams of water tangential to the side cutter 26, a portion of the water striking the cutter and the rest impinging directly against the bottom of the hole.

From the above description it will appear that the non-tracking arrangement of the cutters, the absence of any obstruction retarding penetration, the provision of jets of water against the cutters and the bottom of the hole, the independent rotation of the cutters, the arrangement for covering the entire area at the bottom of the hole and other features of the invention are contributing factors which enable the bit to penetrate rapidly and to remove the earth formation from the hole as fast as it is drilled. Other advantages resulting from the invention include strength and durability oi the parts and convenience in replacing the cutter units when they become worn.

While the invention has been herein disclosed in what is now considered to be a preferred form, it is to be understood that the invention is not limited to the speciflc details thereof but covers all changes, modifications and adaptations within the scope of the appended claims.

What is claimed is:

1. A roller boring drill comprising a bit head having at its lower end a downwardly diverging recess, a toothed roller cutter supported by the bit head in, said recess, means for removing detritus from said cutter, said means comprising a plurality of flushing fluid outlets'in the bit head, one of which is positioned at right angles to the cutter axis to discharge fluid in a radial direction against the cutter and another of which is positioned to discharge fluid tangentially of the cutter.

2. A roller boring drill according to claim 1 in which the last-mentioned outlet is of suflicient width that a portion or the fluid discharged thereby is directed to the bottom or the hole without impinging against said cutter- 3. A roller boring drill according to claim 1 in'which a pair of tangential outlet ports are arranged on opposite sides of the cutter, whereby the cutter teeth are washed as they advance toward, and recede from, the streams of flushing fluid.

CLARENCE E. i

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