Well drilling tool
US 2371248 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
J. J. MGNMARA 2,371,248
March 13, 1945.
WELL DRILLING TOOL Filed April 22, 1942 8 Sheets-Sheet 1 March 13, 1945. 'J J, MQNAMARA 2,371,248
l WELL DRI'LLING TooL Filed April 22, 1942 8 Sheets-Sheet 2 ZJR March 13,1945. J. J MCNAMARA- 2,371,248
-WELL DRILLING TOOL March 13, 1945. J. .1. MQNAMARA WELL DRILLING TOOL 8 Sheets-Sheet 4 Filed April 22. 1942 Ffa J7 *xr cgS.
March 13, 1945.
WELL DRILLING TOOL Filed April 22, 1942 J. MCNAMARA 2,371,248
8 Sheets-Sheet 6 fig f fag I mmmmmmm@ www@ @ JJ Mom, i
f fg@ March 13, 1945. J, MCNMARA 2,371,248
WELL DRILLING TOOL Filed April 22, 1942 8 shets-sheet 8 Patented Mir. 113, 194s UNITED STATES PATENT ori-lcs WELL DRILLING TOOL J olm J. McNamara, Chicago, Ill.
Application April 22, 1942, Serial No. 439,986
The present invention relates to well drills such as are usedin drilling for oil and is particularly directed to the provision of novel means for actuating cutting tools for well drilling. The instrumentality provided is particularly directed to the type of well drill wherein the cutting tools or bits are pounded repeatedly and rapidly so as to chip the formations encountered by the drill, and the material thus broken away is flushed out by means of a fluid that is forced down into the well by a pump. In well drills of this character it is customary to gradually turn the drill at a relatively low rate of speed so as to bring the cutting tools into new positions.
In apparatus of this character it has been previously proposed to use the ushing liquid as a means of furnishing motive power to actuate the cutting tools. Devices of this character however have not to date received general acceptance for various reasons.
, The present invention has for its princiml object the provision of apparatus of the character described wherein the necessary power to actuate the cutting tools ls taken from the power that is stored in the :flushing fluid in such a manner as to enable the operator to maintain adequate pressure and speed of the flushing fluid while taking enough power from a portion of the flushing uid for the reciprocation of the cutting tools. The iiuid generally used in drilling an oil well is a fairly thick mud which is capable of picking up the cuttings in the bottom of the hole and carrying them to the surface.
My invention contemplates a well drilling apparatus wherein the power unit above referred to is so mounted and arranged that it may be coupled onto the end of a fluid delivery pipe as a complete unit, the parts of which are all assembled in an outer shell or casing that is divided by connecting members into separable sections. The upper section of the device comprises merely a connector whereby a huid pipe and a turbine housing are secured to the head or attaching end of the casing. The turbine wheel itself is mounted within the turbine housing and a certain portion of the duid is tapped oi from the main uid supply while the remainder of the fluid is directed into a second pipe of reduced cross section and forced down through the center of the turbine by the pressure upon the liquid being fed downward so as to give the liquid not used by the turbine a considerably higher velocity than the velocity of the liquid entering the branch connection where the liquid to the turbine is tapped from-the main supply.
'Ihe turbine wheel is driven by the tapped o!! liquid and it in turn drives a cam through a speed reduction gear unit, the cam acting to lift a hammer and let it drop twice for each rotation thereof. The hammer and its cooperating spring means for imparting downward acceleration thereto, together with the lifting arms that lift the hammer as the cam is rotated, constitute a section of the device immediately below the turbine, speed reducing gear and cam assembly.
In order to draw off the spent liquid'froin the discharge side of the tube means is provided whereby the liquid that does not enter the turc bine is increased in velocity and discharged into a larger conduit so as to draw od the spent liquid, or in other words, eject it from thedischarge side of the turbine. In this manner I am able to obtain a relatively high emciency in the operation of the turbine while at the same time insuring delivery of the liquid below the turbine at a speed and pressure sumcient for dashing purposes. The last and lower unit of the drill operating assembly comprises a shell which has sockets for the mounting of the stems of a plurality of drill units, each having a number of cutting bits on its lower face. This bottom shell contains also a check valve for preventing reverse now of the heavy huid in the bottom of a well into the drill operating parts as the drill is being lowered in the hole.
The details of the several u will be taken up separately and described, after which the operation of the device as a whole will be more clearly understood.
It will appear from the following description that certain objects and advantages of the present invention are found in the relative arrangement of the several parts to obtain an emcient. compact organization thereof.
Other objects of the invention are the im provement in delivery of the cutting or chipping blow to the stems of the drill units, while still other objects lie in providing a novel mechanism whereby the rotation of the turbine is communicated to the cam without interfering with the discharge of the liquid to the faces of the cutting tools.
Other objects and advantages will appear from the following description and the accompany ing drawings wherein a preferred forni oi the invention is disclosed. It is to be understood however that the drawings 4and description are illustrative only and that they should not be taken as limiting the invention except insofar as it is limited by the cla.
In the drawings:
Fig. 1 is a view on a much reduced scale showing the well drilling apparatus in side elevation;
Fig. 2 is a horizontal sectional view taken through the turbine substantially at the level 2-2 whichis indicated in Fig. 5;
Fig. 3 is a horizontal sectional view taken at the top of the cam element substantially on the line 3-3 indicated in Fig. 6;
Fig. 4 is a vertical sectional view taken through the upper or attaching portion of the apparatus;
Fig. 5 is a sectional view like Fig. 4 taken through the turbine unit and showing the next portion of the apparatus below that shown in Fig. 4;
Fig. 6 is a vertical sectional View taken on the same line as Fig. 5 and showing the speed reduction gear unit and the cam unit of the apparatus;
Fig. '7 is a vertical sectional view taken on the same line as Fig. 6 and illustrating the upper portion of the hammer unit and its connection to the hammer lifting arms which are actuated by the cam;
Fig. 8 is a vertical sectional view taken on the same line as Fig. '1 and illustrating the bottom unit by which the several cutting drills are held in position to be engaged by the hammer;
Fig. 9 is a vertical sectional view through the gear reduction unit. this view being taken at right angles to Fig. 6 and substantially on the line 9-9 of Fig. 10;
Fig. 10 is a horizontal sectional view taken on the line lll-l0 of Fig. 9;
Fig. 11 is a horizontal sectional View looking upward and taken' on the line lI-II of Fig. 8;
Fig. 12 is a fragmentary sectional View taken on the line |2|2 of Fig. 8; A
Fig. 13 is a fragmentary sectional view taken on the line |3--I3 of Fig. 6;
Fig. 14 is a horizontal sectional view taken on the line |4-| 4 of Fig. 6;
Fig. 15 is a view in side elevation of the cam base separate and apart from its connecting structures; and
Fig. 16 is a fragmentary sectional view taken through the center pin of the drill.
It will be noted that Figs. 4 to 8, inclusive, constitute in `eiect a single vertical section through the well drilling apparatus. In certain instances there is a small vertical overlap between the showings of the different figures, in order that a complete illustrationl of the Various parts may be had.
Referring now to Figs. 4 and 5 in particular, the upper connecting unit of the drill apparatus comprises a block 20, preferably a casting, which is threaded with substantially heavy threads 2| along its tapered upper end for connection to the lower end of the drill supporting and turning mechanism. This block has a passage 22 extending vertically through it for the passage of the flushing liquid, as will be readily understood. At its lower end the block 2|] has a depending ilange 23 that is screw threaded interiorly to receive a connecting shell 24 which may also be a casting. The block 28 also has a. large recess 25 which is relatively shallow, and a smaller recess 26 extending upwardly into the block from the base of the recess 25. A pipe 21 passes through the shell 24 from below and is supported on the shell by means of a' nut 28 threaded on .the pipe, the nut 28 being seated in the recess 25. A reduced end 29 is provided on the pipe 21 to extend up into the recess 28. It will be evident that the pipe 21 can be mounted on and suspended from the shell 24 and drawn up to the proper height with respect to the shell before applying the block to the shell. Then when the block 20 is screwed down on the shell the reduced end 29 of the pipe can be forced up into the recess 23 in which it makes a tight fit. A packing 3|! may be provided at the top of the reduced portion 23.
Referring now t0 Figs. 5 and 2, it will be noted that in Fig. 5 the shell 24 and the pipe 21 extend downwardly from their connection with the block 2|). The shell is screw threaded as indicated at 3| to receive a casing 30 and support the same.
`A turbine body 32 fits inside the casing 30 and has a neck portion 33 that is threaded onto the pipe 21 by threads 34. The turbine body 32 is provided with an inlet opening 35 communicating with the interior of the pipe 21 so as to receive fluid under pressure. From the inlet opening 35 there are four diverging uid conduits 36a, 36h, 36e and 36d (not shown). There is also a downwardly directed conduit 31 which extends axially through the turbine body 32. As shown, this conduit gradually reduces in diameter until it meets with the upper end of a pipe 38 that is threaded into the turbine body 32. The turbinebody has an annular flange 39 at the top thereof and is cut away to provide an annular recess 40 which begins at the outer ends of the conduits 36a, 36h, 36o and 36d and extends downwardly to and below a series of angularly disposed annularly spaced openings 4| which are directed inwardly through a relatively thin wall portion 42 of the turbine body to a rotor-receiving space 43 provided in the turbine body. A rotor 44 is journalled in the body 32 by a bearing 45, a suitable packing gasket 46 being provided immediately beneath the bearing ring 45.
The recess 40 is closed by an outer sleeve 41 which is placed on the rotor body 32 and secured in place by welding or otherwise after the body is formed.
The rotor 44 has an extension 48 which is seated in and guided by a plate 49. The rotor 44 has a multiplicity of blades 50 so arranged as to receive the fluid from the nozzles 4| at an effective angle as illustrated in Fig. 2. The blades 5l) are joined to each other at their lower ends by a ring 5I which is integral with the blades. The upper ends of the blades are joined together by a web 52 which forms a part of the body portion of the rotor. It will be noted that the rotor is so mounted in the turbine body as to be spaced from and unsupported by the pipe 38. It will also be noted that the spent fluid leaving the rotor flows downwardly and outwardly along a curved surface 53 provided in the body of the rotor. The spent fiuid directed outwardly and downwardly by the body of the rotor is carried downwardly through the plate 49 through apertures indicated in dotted lines at 54 and 55 (Fig. 5). The relative position of these apertures with respect to the mechanism below the plate 49 will appear more fully from the description hereinafter made in connection with Figs. 3, 6, 9 and 10.
Referring now to Figs. 3, 6, 9 and l0, and particularly to Fig. 6, the construction immediately below the turbine will be described. It will be noted that the pipe 38 continues downwardly through the center of the rotor 44. A speed reduction gear unit 56 is placed directly below the plate 48 and rests on a second plate 51 which in turn rests on a cam mounting block 58. The
asuma block B has a recess 89 in which avcam Il! is rotatably mounted. The cam 80 is drivingly connected through the gear unit 58 to the rotor ll.
The gearjnnit 5B comprises a body 8l having a central aperture to receive the pipe 3B and having upper and lower recesses 62 and t3 to receive the gears of the unit. The part 48 on the rotor has a reduced extension 6l which extends down into the recess 62. A pinion B5 is fixed on the extension 64 by a key or other means so as to rotate with the extension. The gear 6b meshes with two gears 68 and 61 which are keyed to a pair of shafts 68 and 69. The shafts @il and 69 are larger at their upper ends and extend down through a partition wall 'ill betweenthe recesses tt and S3 where they have keyed to them gears lll and l2, respectively. That is, the shait 39 has the gears 61 and 'I2 keyed thereto. The shaft has thegears 66 and l ikeyed thereto. The gears 'il and 12 mesh with a gear i3 which is fixed by a key or otherwise to a depending' hollow shaft lil, the hollow shaft Il being extended down into the cam 69 and connected thereto in a manner which will be presently described. Itwill-be noted that the plates I9 and 57 are recessed to receive the opposite ends of the shafts 68 and 69. Speed reduction is obtained by making the pinion 65 relatively small with respect to the gears 96 and 8l and by making the gears 1i and 12 relatively small with respect to the gear 13. The particular speed ratio thus obtained between the rotor W and the shaft 1I is determined by the relation of the several gears in the speed reduction unit 56.
The body 6I provides ball bearings 'i5 lor the lower end of the extension 64, these bearings being mounted in the partition 10 as shown clearly in Figs. 6 and 9. The body 6I and its associated gears are fastened between the plates t9 and 5l by four screw bolts 18. These screw bolts have their heads countersunk in the plate t9 and are threaded into the -plate 51. The entire assembly comprising the plates 49 and 5l and the speed reduction unit 56 is held in place on the block bd by four screw bolts 'l1 placed at the four corners of the unit 5B. v'lhese screw bolts have their heads countersunk in the plate il@ and are threaded into the body 58. The plate bl is pro vided with apertures 54 and 55' corresponding to the apertures 54 and 55 in the upper plate I9.
The block 58 has already been described as having a recess 58 to receive the cam til. The driven shaft 'I4 has a head 18 thereon, which head interlocks with a plate i9 that is riveted to the cam 6U. The details of this construction are shown more fully in- Fig. 13. The head 1d is cut out so as to provide four depending lugs d@ spaced 90 apart around the periphery of the head lid.
The plate 'i9 is notched on its periphery to receive the lugs 80. It is considerably easier to cut the plate 'i9 to the shape to receive the lugs dd and then rivet it to the cam than it would be to cut the necessary recesses in the cam material itself for the lugs B9. 'I'he cam 69 is supported in the block 5t by a ball bearing ill It is understood of course that the pipe tt continues down through the head it and through the cam til and that the actual bearings which to match up with the apertures in the plate U1 in order to direct the uid downwardly intothe block B8. Immediately below the web 82 the block 58 is cored'out to provide inwardly ex# tending passageways 8l, 88, 89 and 90 (see Fis. 14) These passageway/s are arranged so that the channels 83, 8i, 8d and Blvopen into them and they extend inwardly to a chamber 9i which surrounds the lower end 92 of the pipe 38. lower end 9i? is reduced to form a nozzle which is adapted to discharge the iluid which has been byfpassed around the turbine straight down at a high velocity. The chamber 9i opens into the interior 9d of a conduit b4 which is threaded into the bottom oi the block bt. There are four webs Qt, 93, 91 and 99 separating the passageways di, tt, t9 and 9d, but these webs extend only to the 'chamber 9 i The function of the nozzle or reduced end tt oi the pipe 3d is to restrict the cross section of the pipe so as to cause the huid flowing down the pipe to be increased in velocity so that it will `entrain and carry away the spent fluid that is discharged from the turbine and passes downwardly through the apertures 5t', 5E' and the channels and passageways in the block tt. This relieves the pressure on the discharge side of the turbine and enables it to function more emciently. Also, since a comparatively high velocity is required for the fluid as it passes on down to the drill bits it ,is essential that the by-passed huid be capable of imparting enough energy to the total mass of iiuid iiowing down the passage @t to enable the fluid to carry away the material that is loosened or chipped o3 by the drill bits.
The block Bt serves also as av guide for two hammer operating arms 99 and it. As shown best by Figs. 3, 6 and 1d, these arms ride upon the top surface oi the cam 6U. They have lateral projections lill and it? extending over the cam. The block t9 is grooved at it and itt to receive the arms 9b and itil and guide them in their vertical movement. The rotation of the cam t@ is such that the arms are lifted as the extensions ll andv E02 ride upwardly on the inclined surfaces lb and lult of the cam (see Fig. 15). The weight of the hammer and the force of a spring lill which presses down on the hammer move the lreep the parts aligned prevent them from wearhammer downwardly when the extensions it! and iti pass od the high ends of the surfaces itt and |06. It will be noted that for each complete revolution of the cam the arms are lifted twice.
The connection between the arms t@ and itt and the hammer itt is illustrated in Fig. 7 of the drawings. The hammer comprises a cylindrical metallic body with a central opening through which the pipe 9d passes. The spring il'l is intei-posed between the top of the hammer and the bottom of the body t8 and is of sumcient size and strength to give the desired downward impetus to the hammer for actuating the drills. The two arms 99 and tilt are connected to the hammer in the same fashion so a description of one connection will sumce for both. The hammer is provided with a recess idd extending down from the top thereof and the arm is provided with an oilset at llt and a depending mounting portion lli that extends down into the recess m9. The hammer and the mounting portion il l are drilled to provide openings to receive a locking key l it. The key H2 iits snugly in the hammer and is slightly longer than the thickness of the hammer from the pipe 9i out to the shell tit so that the key Md may ride upon the shell and pipe. There is nels n. u, n and as which are so arranged as l oi' course enough clearance to avoid any appreeiable friction or binding of the key against either the shell or the pipe. The aperture in the mounting portion I is slightly greater in vertical depth than the vertical depth of the key ||2 so as to provide a small space ||`3 as shown in Fig. 7. Beneath the mounting portion II| the hammer is provided with a spring receiving recess ||4 in which a spring I|5 is mounted. This spring is of suicient strength to press the hammer mounting portion I| I upwardly to the position shown in Fig. 7.
In operation, when the arms 99 and |00 move oi the top portions of the cam surfaces that lift them the hammer is of course forced downwardly at a rapid rate by its own weight and by the pressure of the spring |01. When the hammer strikes the tops of the drill shanks to be hereinafter described it stops suddenly. The springs ||5 tend to cushion the downward movement of the arms 99 and |00 at this point and the clearance provided at. I3 and in the bottom of the recess |09 permits a slight vertical movement of the arms 99 and |00 with respect to the hammer to, in a measure, overcome the eiect of the rebound of the hammer.
Referring now to Figs. 7 and 8, it will be noted that the lower end of the hammer |08 is 'spaced slightly above the top ends of the drill shanks IIB of which, in the present device, there are four. The hammer is also provided at its lower end with a recess ||1 in which the upper coils of a spring ||8 are housed. This spring I|3 encircles the pipe 94 and rests upon the top of a drill shank mounting head I|9. The drill shank mounting head is provided with a central opening |20, the upper portion of which is enlarged and threaded to receive the lower end of the pipe 94. The enlarged portion of the opening or passage also receives a check valve |2| which is actually held in place by the 'lower end of the pipe 94. It will be observed that the casing is slightly enlarged or thickened at its lower end and is threaded Onto the head ,I I9. The head I |9 increases slightly in diameter from the top to the bottom as shown by Figs. 1 and 8. It is a solid block, preferably a casting, which is bored to receive the drill shanks I I6 and to provide a passageway for the uid that is fed down through the pipe 94.
The check valve |2| is provided to prevent backiiow of the fluid through the pipe 94 which might cause the device to get clogged up with the fluid and the cuttings of stone that are entrained thereby. This valve comprises a block |22, an upper end plug |23 which provides a seat for a valve |2'4, and a lower end plug |25. The block |22 is hollowed out to provide a chamber |2` immediately below the valve |24 and a multiplicity of passages |21 are spaced circumferentially about the block |22 to pass the uid through the block. The block |22 is also centrally bored to receive a valve stem |28 for the valve |24 and to receive a spring |29 which normally urges the valve |24 to closed position and which is held in place by the plug |25. Below the valve block |22 the passage |20 is restricted for a short distance and then divided into four passageways |30, |3|, |32 and |33 that open downwardly on the lower face of the head ||9. The position of the passageways just mentioned is such that they diverge downwardly and discharge between the four drills |34, |35, |36 and |31 which are carried by the head II9.
On the bottom face of the head ||9, at the center thereof, a screw threaded recess |38 is proasuma 'to rest on the material at the bottom of the well.
The tip |4I preferably is made by inserting a hardened plug |4|a in the end of the pin |39.
The several drill units |34, |35, |36 and |31 are alike in construction and in their mounting in the head Il! so a description of one of the units and its mounting will suiflce for all. Each drill unit comprises a plurality of cutting tool/s |42 which are mounted in a block |43 in such a way as to be readily replaceable, each cutting tool being backed up by a removable plug |44 that is held in place by a cap |45. The particular details of this co'nstruction form no part of the present invention. They are claimed in a separate application led by the applicant and therefore will not be described further here.
The drill shank IIS is fixed to the cap |45. The shank extends upwardly through an aperture |46 that is provided inahe head ||9. This aperture, at its upper end, is of just such diameter as to make a snug sliding fit with the drill shank I I6 as shown at |41. A short distance from the top of the head I9 the aperture |46 is enlarged to provide room for a cup washer |49 and a spring |49 i which together with a split ring |50 serve to support the shank and the cutting tools carried thereby in the head ||9. The spring |49 is in turn supported at its lower end by a packing washer I5| that rests upon rings of packing |52, the rings of packing being held in a threaded and shouldered sleeve |53. The sleeve |53 has external screw threads that thread into an enlarged portion |54 of the aperture |46. The sleeve has a shoulder |55 to engage the bottom surface of the head ||9 around the aperture |48. The sleeve is also provided with a shoulder |56 on which the packing rings |52 rest, and the sleeve is shaped as indicated at |51 to receive the lower end yof the shank |I6, which end is somewhat enlarged.
When the hammer |08 strikes the upper ends of the drill Shanks IIB these drills are given a sudden downward movement which causes the cutting too-ls |42 to strike the stone or other formation in the bottom of the well a sharp blow. At the same time the springs |49 are being compressed so as soon as the downward movement of the drills is stopped they are immediately forced upward by the recoil of the springs |49. Sinceit is possible to get quite rapid action of the hammer |08 from the cam 60 the cutting tools can be made to strikea multiplicity of blows in rapid succession so as to accomplish high speed drilling however remote the drilling apparatus may-be from the surface of the ground. Means are provided whereby the entire drill unit is given a slow rotational movement so as to continually bring the cutting tools into engagement with new surfaces in the bottom of the well, the liquid being discharged from the passage |20 serving to wash away the material and carry it up outside of the casing 30 as the drilling operation proceeds. The means to rotate the drill unit are Well known and therefore no showing of such means has been made in the drawings.
It is believed that the operation of the apparatus hereinbefore described will be readily apparent from the detailed description. Brieily,
this operation may be stated as follows: the washing uid by which the material to be drilled is brought to the surface of the ground is directed into the drill unit shown in full in Fig. 1 at the top thereof. Naturally the pressure imparted to the uid will depend upon the force necessary to carry the liquid and the removed material from the bottom of the well to the sur face of the ground. Pumps now in use, however, develop sufficient pressure and fluid iiow t serve this purpose. vide the ow of fluid near the top of the ldrill unit. One portion of the fluid, and in fact the main portion thereof, is directed downwardly through the pipe 38 in a restricted. passage so that it is given an increased velocity in order to effect the required volume of flow. The remainder of the liquid is fed to the turbine blades 50 of the turbine so as to cause the rotor 44 to-turn at a relatively high speed. 'As the rotor 44 turns it drives the cam 60 through the speed reduction unit |i.` The cam in turn repeatedly lifts the hammer |08 and lets it fall so that the hammer may strike the drill stems and give the cutting tools the -proper sudden sharp impact that they need to cut away the formation at the bottom of the well. Advantage is taken of the velocity of the fluid in the pipe 38 to draw oi the spent iluid` from the back side of the turbine thus preventing back pressure from cutting down the efficiency of the tunbine. The spent uid from the turbine and the by-passed liquid are combined and flow down through the pipe 94 and the passage |20 to finally reach the lower face of the drill head ||9 at a velocity suiiicient to pick up the cuttings and carry them upwardly around the drilling apparatus.
The assembly is such that several parts can readily be put together before putting them in the casing 30. It will be noted that the entire drill head ||9 and its drill assembly are completely independent of the rest of the apparatus except for the screw threaded connection. Once the drill head is removed and the connecting head is removed the rest of the apparatus can be taken out by disconnecting the casing from the shell 24. l
The particular means of mounting the drill Shanks in the head 9 makes it easy to assemble any particular drill shank. The washer |48 serves both as a'means of holding the spring |49 under compression and as a means of holding the split ring |50 in place. This split ring may be in two sections, each a semi-circle. In order to apply the split ring it is necessary to compress the spring |49 enough to bring the top edge of the cup washer |48 below the level of the annular depression provided in each of the drill Shanks; then the split ring can be dropped in the depression after which the washer |48 by virtue of its peculiar cup-shaped portion |48 (see Figs. 8 and 12) serves to lock the split ring in position and to stop the upward movement of the washer at the ring.
The check valve |2| readily opens under downward pressure of uid ln the pipe 94 but immediately upon failure of the downward pressure this valve closes under the influence of its enclosed The present drill functions to di` spring |29 to eliminate danger of iiuid and cuttings, mud and the like, getting back inside of the pipe 94 and the block 58 where it might clog the entire system. The check valve is simple in its construction and its mounting does not in any way interfere with the connection of the head IIS to the rest of the drilling apparatus.
I have found that in connection with the packing rings |52, these rings have to take a great deal of punishment and if I use a coiled packing and cut the rings separately, staggering the joints, they will last much longer.
In connection with the speed reduction gear unit, I have found the particular assembly shown herein to be quite effective and practical both from the standpoint of simplicity in putting it together and into the assembly of theentire apparatus. However, it is obvious that any suitable speed reduction unit may be interposed between the rotor 44 and the shaft 14. In fact, where the speed of the rotor is not excessive with respect to the desired speed of operating the cutting tools the speed reduction gearing may be dispensed with entirely.
From the foregoing description it is believed that the nature and operation of the present apparatus will be readily apparent to those skilled in this art. Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:
1. A well drill comprising in combination, a supporting body having a passageway extending downwardly from the top thereof, whereby a uid under pressure may be supplied to the drill, a water turbine supported by said body, a bypass conduit having its inlet end in said passageway and adapted to direct a portion of the supplied fluid past the turbine, other conduit means connected to said passageway to direct the remainder of the fluid to the turbine whereby to effect rotation thereof, discharge conduit means extending down from the turbine for the spent fluid from the turbine, said by-pass conduit including a nozzle directing the by-passed fluid downwardly at an increased velocity into the discharge conduit for the spent fluid, a cutting tool carried by said supporting body, means connected to the turbine to actuate the cutting tool, and meansV to direct the combined spent iluid and by-passed uid to the vicinity of the cutting tool for washing away the cuttings, said last named means including means to prevent iiow of fluid and cuttings into the apparatus from the cutting tool end.
2. In a w ll drill, a supporting body having a water inlet conduit entering it at the top, a water turbine in said body and having a rotor, means to direct part of the water from the inlet conduitto the turbine rotor, means comprising a conduit extending through the turbine rotor to direct the remainder of the water axially through the turbine rotor. and means below the turbine directing the spent water from the turbine inwardly to the axially directed stream for distributing the energy of the said remainder of the water to the water dlscharged'from the turbine.
JOHN J. MCNAMARA.