US1388424A - Rotary bit - Google Patents

Description

| 19. 1,388,424, Patented Aug. 23, 1921.

' 3 SHEETSSHEET I- E. A. GEORGE.

ROTARY BIT.

APPLICATION FILED JUNE 27, 1919.

1,3 3,424, PatentedAug. 1921.

a SHEETS HE T 2.

E. AGED RG5, Shwwtoz E. "A. GEORGE.

NE 27, 1919. I I

Patented Aug. 23, 1921.

'3 SHEETSSHEET 3.

ROTARY Bl LED JU APPLICATION Fl 514w "to:

5; AGEORCTE,

UNITED STATES,

PATENT OFFICE.

EDWARD A. GEORGE, 0F SHREVEPORT, LOUISIANA.

ROTARY BIT.

T 0 all to ham it may concern:

Be it known that I, EDWARD A. Gnoncn, a citizen of the United States, residing at Shreveport, Caddo parish, Louisiana, have invented a certain new and useful Improvement in Rotary Bits, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to rotary drills of the roller type for use in drilling oil, water,

and gas wells, and mines. In this type of drill the bit is attached at the lower end of a hollow drill stem which is rotated to cause the cutters on the forward end of the bit to roll on the bottom and sides of the hole and thus disintegrate the material which is washed upwardly to the surface of the ground by means of a stream of flushing water pumped downwardly through the hollow drill stem and through channels in the bit itself to the bottom of the hole.

An object of my invention is to provide a bit of the roller type which has cutters thereon of novel construction, the said out ters being angular in form and adapted to rotate on approximately upright shafts in the lower head of the bit.

Another object is to provide a plurality of cutters mounted on the lower end of the bit in such manner as to most efiiciently dig into the material at the bottom of the hole and to preserve the gage at the side of the hole.

Another object is to so mount the cutters that the thrust of the cutting action will be efliciently taken up in the head of the bit without danger of breaking or mutilation of the cutters.

Other objects and advantages will more' clearly appear in the specification which follows and will be emphasized with more particularity in the claims attached hereto.

Referring to the drawings forming a part of this specification, and wherein like parts are designated by like numerals throughout the several views, Figure 1 is a central longitudinal section through the head of my improved bit; Fig. 2 is a bottom plan View thereof; Fig. 3 is a central longitudinal section of the same, taken at right angles to the view shown in Fig. 1; Fig. 4 is a side elevation of the invention; Fig. 5 is a transverse section through the head of my bit taken on the plane 5-5 of Fig. 1; Fig. 6

ters will be to act upon the Specification of Letters Patent. Patented Aug, 23, 1921,

1919. Serial No. 307,098.

is a top plan view of the shank of my bit showing the position of the water and oil ducts therein; Fig. 7 nal section through a different embodiment of my invention; Fig. 8 illustrates a different means for mounting the cutter shaft in the head of the bit; and F ig. 9 is a still different embodiment of one of the cutters used in my invention.

My improved bit is made up of a head 1 somewhat cylindrical in shape and having a plurality of longitudinal flutes or grooves 2 in the outer periphery thereof, as shown in Flgs. 2 and 5, to accommodate the flow of flushing water past the head of the bit. The head 1 has an upwardly extending shank 3 of reduced diameter, threaded at 4 for attachment to a drill collar. The lower face of the head is provided with four cutters. Two of these cutters are inclined slightly outward at the bottom, forming an upright cutting portion to act upon the outer periphery of the hole and to maintain the gage thereof. Two intermediate cutters 6 are inclined inwardly at their lower ends so as to cut away the central portion ofthe bottom of the hole. By reference to Fig. 2 it will be seen that the outer cutters 5 and the inner cutters 6, are so positioned that when the bit is rotated the combined effect of the cutwhole surface of the bottom of the hole and to drill into the material at all points. a

The cutters shown in my improved bit are somewhat elongated in formation and angular in outline so as to provide four side cutting teeth 7 on each cutter. These teeth are inclined slightly inward toward the lower end, forming cutters of an approximately frusto-pyramldal form. The lower truncated end of the pyramid is also tapered 8, and the teeth on the continued abruptly Between the our slightly to a point at side of the cutters are inward to this point.

teeth 5 of each cutter, the side of the cutter is fluted Tor grooved at 9 so as to provide a better cutting point at each angle thereof. The inclination of the two outer cutters 5 is such that the inclined or tapered face at the outer sides of the cutters shall'be in parallel relation with the side of the hole. In other words, the side teeth 7 are parallel with the side of the head 1, but are so mounted as to project somewhat beyond the sides of the head in order to cut a eter than the head of the bit so that there is a central longitudihole of larger diam- V will be no tendency of the bit to wedge or lodge in the hole.

The two intermediate cutters 6 are shaped identically like the cutters 5. tion of the inner cutters, however, is toward the center of the head, and the angle is such that the side faces are vertical along the line of the central axis of rotation of the bit. This fact is shown articularly in Fig. 3. The inward edges of these two cutters are spaced somewhat apart, however, to allow them to rotate freely. They are close enough together, however, so that with the ordinary vibration or whipping action, which takes lace as a drill bit is rotated,

the cutters w1ll serve to prevent the 'formation of a core at the center ofthe bit.

The upper shank 10 of each of the cutters is cylindrical in shape and of reduced diameter. This hank is preferably threaded to accommodate a bearing sleeve 11 thereon. Said sleeve is of hardened material and is provided at a point intermediate the ends with a peripheral groove 12, into which a set screw 13, or similar holding means, is fitted to allow rotation of said cutter, as shown particularly in Fig. '1. The bearing sleeve is adapted to seat rotatably within an outer journal bearing 14 within the socket 15 in the head. At the upper end of the shank 10, and journal 14, is an anti-friction washer 16 fitted within the socket 15 and forming a thrust bearing for the upper end of the rotating cutter.

These bearings are the same in each of the cutters of my preferred embodiment. Lubricant is supplied to the bearings from a central upper channel or container 17 in the head of the bit. This channel is filled with lubricant and the upper end is closed by means of a threaded plug 19 to prevent the entrance of water or other material therein. Branching ducts 20 lead from the lower end of this channel to the upper bearing washer 16 and through a registering channel therein to the bearing surface of the cutter.

Flushing water is supplied to the cutters through two channels 21 leading from the upper ends of the shank of the bit downwardly in an inclined direction for a distance, and then directly downward to issue at a point in advance of each of the side cutters 5. The central cutters 6 are supplied with water through a central water channel 22, which receives its water from an inclined channel 23 leading from the upper end of the shank downwardly at an inclination to theupper end of the channel 22. By means of these water channels, a stream of water is discharged immediately in front of each of the side cutter 5 and immediately between the two central cutters 6 so that the cuttings will be washed away from the cutting points of the bit and thus not impede "its progress The inclinaably within longitudinal grooves 26 in the sides of the head. They are retained against longitudinal movement within these slots by meansof set screws 27. These blades project from the side of the head for a distance such that when the sharp edges 7 of the cutters 6 have been worn slightly the reaming blades will engage the side of the hole and will assist in maintaining the gage of the hole and therefore prevent the wedging of the head therein.

In Fig. 7 I have shown a modified form of bearing and a modified means for lubrication. The bearing sleeve 11' is threaded onto the shank 10 of each of the cutters in the same manner as previously described. It has, however, a lower laterally extending flange 28, the upper face of which acts as a seat for packing washers 29. The outer journal sleeve 14 is also laterally extended at 30 and provided with an annular inner recess to receive the said packing washers 29, and thus maintain a fluid-tight bearing against the entrance of foreign material thereto. There is also a roller bearing 38 arranged between the upper face of the shank 10 of the bit and the bearing washer 16 at the upper end thereof. This roller bearing serves to take up the upward thrust of the cutting action in a more eflicient way and will assist in the easy operation of the cutters.

The lubricant in this operation is contained in separate channels 31, bored in the sides ofthe bit, as shown in Fig. 7, and closed at the upper end by threaded plugs 32. These channels are filled with lubricant when the bit-is introduced into the hole, which lubricant gradually passes downward through ducts 33, through the thrust washer 16 and registering channels 34, in the upper part of the shank 10, these channels. having laterally branching portions conducting the lubricant to the side ofthe bearing sleeve 11, as shown in the drawing., This form of bearing is otherwise the same as that previously described and {will need no further explanation. It has some advantage, however, over the previously described bearing, in that the lubricant is retained upon the bearing by means of the packing washer 29, and the roller bearings tend to give the cutters a freer rotation than the ordinary bearing. Flushing water is supplied to the cutters in this embodiment through a single central channel 22'.

In Fig. 8, the bearing sleeve is omitted and I have used an outer journal sleeve 14", similar to that disclosed in the previous modifications. There is, however, a recess on the inner face of the journal sleeve into which packing washers 29 may be threaded. The shank of the bit is retained within the bearing in this modification by a threaded engagement with the upper washer 16". This engagement is by means of a central downwardly projecting screw portion 35 on the said washer, this screw being threaded into engagement with the upper end of the shank 10", as shown. In assembling this form' of cutter. the washer 16" is placed within the socket in the head and the journal 14" is then threaded in place so as to 1 form of bit, the thrust washers 16 are retain the washer in position in the socket. The cutter is then fitted within the journal sleeve and rotated in a left-hand direction and threaded upon the screw portion 35 of the washer. The rotation of the bit is ordinarily in a right-hand direction and this causes the cutters to roll in the same direction, thus preventing the tendency of the cutter to unscrew from the washer l6", and become lost in the hole.

In Fig. 9, I have shown a cutter with a bearin similar to that shown in Fi 7, but with the ball-race omitted. The ushing water is supplied in this modification directly to the sides of the cutters themselves through channels 36 in the head, these channels being inclined downwardl to pass through the thrust washer 16 and t e shank 10 of the cutter to the central portion there of, and from thence through branching ducts 3"(,to the outer grooves 9 in the faces of the cutters. This means of flushing the cutters free of the detritus has some advantages in that the water impinges directly against the material being cut by the bit, and this 'will more efiiciently clear the cutters of all disintegrated material.

The lubrication for this type of cutteris similar to that shown in Fig. 7, there being lateral containing chambers 31' from which small ducts 33 conduct the lubricant downwardly to the upper face of the thrust washer 16'.

In assembling the cutters in my preferred fitted within the socket 15 in the head,'the journal sleeves 14 are then inserted therein, the bearing sleeves 11 are threaded over the upper shank 10 of the'cutters and introduced within the journal sleeve 14. The set screws 13 are then threaded through the journal sleeves 14 into the grooves 12 in the bearing sleeves 14. The screws thus serve to retain the journal sleeves 14 in place and also retain 'cutters are rolled upon the bottom and sides of the hole. This rolling movement will give a rotation to the cutters, acting'to dig into the bottom of the hole with the forward cutting faces and to shear away the material from the sides and bottom of the hole with the lateral cutting edges 7. This type of bit will be found to be very efiicient in operation as the cutters are adapted to act upon the bottom of the hole with a sharp scraping action, and the sides of the cutters act to maintain the gage of the hole at the sides thereof. Furthermore, the thrust of the cutting action is directed inwardly toward the head of the bit in such manner that the force of this'thrust is taken up efficiently in the bearings in the head so that there will be little tendency for breaking or wear on the operative. parts.

Having thus described my invention, the further advantages of which will be obvious, what I claim as new and desire to protect by Letters Patent is:

1. In a rotary boring drlll, a head, approximately upright cutters rotatable in sockets in the forward face of said head, and having a tapered forward cutting face and laterally tapered cutting edges so arranged that one side thereof is parallel with the sides of the bore being drilled, the other face being adapted to cut the bottom of the hole and each cutter positioned to bear upon the bottom of the hole.

2. In a rotary boringdrill, a head, four approximately upright cutters of uniform size mounted on pins rotatable in sockets in the lower end thereof, said cutters being approximately pyramidal in shape to provide four longitudinal cutting teeth on the sides and four radial teeth on the forward face thereof, said cutters arranged to drill a cylindrical hole.

3. In a rotary boring drill, a head, approximately upright cutters projecting from the forward end of saidhead, said cutters being approximately rectangular in transverse section and having four inclined longitudinal side teeth and forward cutting faces adapted to act upon the bottom and sides of the hole being drilled, the longitudinal side teeth of one set arranged parallel with the side of the hole and adapted tov out both the side and bottom of the hole. 1

4. In a rotary boring drill, a head having approximately upright bearin sockets in the forward end thereof, forwar ly' projecting adapted to drill the bottom of the hole, one

side of each of said cutters being arranged parallel with the sides of the hole.

5. In a rotary boring drill, a head, four cutters of uniform size symmetrically arranged on the base thereof to drill a cylindrical hole, said cutters having integral shafts rotatable in sockets in the said head, two of said cutters being inclined slightly inwardly toward the central axis of the head to cut the central portion of the bottom of the hole, and two cutters inclined slightly outwardly away from said central axis to cut both the bottom and sides of the'hole.

6. I11 a rotary boring drill, a head with bearing sockets in the base thereof, polygonal cutters mounted on integral shafts projecting upwardly into said sockets, bearing plates in the ends of said sockets to take up the thrust at the upper ends of said shafts, and longitudinal teeth on the four corners of 'said cutters arranged to cut the full bottom and the sides of the hole.

7 In a rotary boring drill, a head, cutter shafts mounted in sockets therein, cutters integral with said shafts, said cutters being approximately pyramidal in shape, a longitudinal tooth at each corner thereof, a groove between said teeth, and the said shafts being so inclined as to bring said teeth on one side of each cutter into parallelism with the side of the hole.

8. In a rotary boring drill, a head having bearing sockets in the base thereof, said sockets inclined slightly from the vertical axis of the head, tapered cutters mounted on integral shafts journaled in said sockets, longitudinal teeth on the tapered sides of said cutters, the cutters and said teeth being so inclined and positioned as to-have one side face parallel with the vertical axis of the head, and a tapered forward cutting face on each cutter for the purpose described.

In testimony whereof, I hereunto afiix my signature, this the 24th day of June, A. 1)., 1919.

EDWARD A. GEORGE.

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