US1269449A

US1269449A - Method of and apparatus for forming and enlarging or cavating bores.

Info

Publication number: US1269449A
Application number: US9676416A
Authority: US
Inventors: Howard R Hughes
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-05-11
Filing date: 1916-05-11
Publication date: 1918-06-11
Anticipated expiration: 1935-06-11

Description

H. H. HUGHES.

METHOD 0F AND APPARATUS FOR FORMING AND ENLARGING 0R CAVATING BOHES.

APPLICATION FILED MAY Il. 1916.

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IIIIIIIII I H. R. HUGHES.. METHOD 0F AND APPARATUS FOR FOHMING AND ENLARGING 0R CAVATING BORES.

' APPLICATION FILED MAY III 1916.

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H. R. HUGHES. METHOD 0F AND APPARATUS FOR FORMING AND ENLARGING 0R CAvATlNG BORES.

APPLICATION FILED MAY II. I9l6.

l 269,449., Patented June 11, 1918.

4 SHEETS-SHEET 3.

IIIIIIImIIIIIIIIIIIIIId H. R. HUGHES. METHOD 0F AND APPARATUS FOR FORMING AND ENLARGING 0R CAVATING BORES. APPLICATION FILED MAY I1, IsIe.

4 SHEETS-SHEET 4.

w w Z I 1m Patented June 11, 1918.

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I mi IWW www5 naaien aruba HOWARD R. HUGHES, OF NEW YORK, N. Y.

METHOD OF AND APPARATUS FOR FORIVIING AND ENLARGING- OR CAVATIN'G BORES.

manages.

Specification of Letters Patent.

Patented June ill, 1918.

lApplication filed May 11, 1916. Serial No. 96,764.

To all 'uhom 'it may concern:

Be it known that I,- HOWARD R. HUGHES, a citizen of thc United States, residing in New York, in the county of New York and State of New York, have invented certain new and` useful Improvements in Methods.

of and Apparatus for Forming and Enlarg'ing or Cavating Bores, of which the following is `a specification.

The present invention relates to a method of and an apparatus for digging or drilling a bore or tunnel in the ground through earth, rock or other material in either a Vertical or horizontal or an intermediate direction and of then enlarging a part of said bore or tunnel without withdrawing the apparatus from the ground.

. In the forms of apparatus previously used in the art, it has been found necessary in many kinds of operations to enlarge the drill hole of a tunnel or well usually at the forward end of the hole, so as to provide a larger capacity for the accumulation of -wateror oil in a well or for the placing of machinery or of explosives at the end of a. tunnel or shaft. In performing this operation it has beenl the custom to drill the hole, withdraw the drilling apparatus, then insert an expanding reamer and enlarge the -bore in a separate operation. This method has been found to be a very expensive one, in that a larger amount of time is usually required for the two separate operations and a great deal'of expense is also involved. The element of time is of a special consequence in drilling bores in undermining the -enemys trenches in warfare where a delay of a. few hours may be of vital importance. It is to overcomethis objection and to combine ,a drilling and a cavating or enlarging operation so that the two acts may be performed in one continuous operation that 'the present device was invented. The principal object of the present `improvement is hence to provide a device for enlarging or cavating the end of a drill hole or bore without withdrawing the main or pilot drill from the ground. .j l'

Another object is to provide alreaming or enlarging mechanism which'may be main-y tained inoperatively within the hollow drill` steml during the `drillingjof the bore, "and which isadapted to b e easily forced` forward into operative'position when it is desired to enlargethe end Vofthe bore.' y

` Another object is toprovide a pilot drill which is easily disconnected from the drill stem, and an enlarging or expanding reamer within the drill stem which can be advanced by Huid lpressure into operating position to cavate the end of the bore.

Another object is'to provide a new and improved method of enlarging or cavating a bore or tunnel without withdrawing the drill from the ground and with the consequent valuable decrease in the amount of time and expense necessary for the complete operation.

Other objects -to be accomplished by my improved apparatus will more clearly appear in the description which follows.

My said invention is fully shown, described and claimed in the following specification and claims, of which the accompanying drawings form a part, wherein similar reference letters or numerals of reference designate like or equivalent parts, wherever found throughout the several views, and in which:-

Figure l is a view in central longitudinal Section of my improved cavating mechanism,y showing one of the enlarging-blades extended into operative position; such view being taken substantially on the line 1-.1 of Fig. 2, looking from left to right thereof;

Fig. 2 is a like side view of the same mechanism, in substantially central longitudinal section, taken at a right angle to the section shown in Fig. 1, also looking from left to right.

Fig. 3 is a side perspective View in-detail of the mechanism supporting sleeve removed, looking from left to right of Fig. l;

Fig. 4 is a longitudinal' vertical view thereof, taken on the same section as Fig. 1, with the pilot-boring-bit removed, showing the expanding cavating-'bit mechanism in its' Y' Figr'? isa bottom plan view showing the expanding bit-mechanism iny the fully Vexpanded4 position. v

Fig. 8 is a sectional topv'view of such mechanismftaken substantially onthe .line

8-*8 of Fig. 1; Fig. 9 is a like section thereof taken substantially on the line 9-9 of Fig. 2, looking upward, the expanding cavating blades being removed.

Fig. 10 is a side detail View, and Fig. 11 a like side face view of the upper securing the head end of one of the expanding boringblades;

*ig 12 is a detail side view in central longitudinal section, of the cutting end of one of the blades of the simple one piece form shown in Figs. 1, 2, 7 and 8;

Fig. 13 is a view in central longitudinal section of the bottom portion of an artesianwell vertical bore-hole showing my improved enlarging cavating-bit mechanism in the cavating position therein; the pilotboring-bit being shown disengaged therefrom and at the bottom of the pilot-bore;

Fig. 14 is a side perspective -face view; and Fig. 15 a like view of the mechanism shown in Fig. 14, looking toward the right of Fig. 14 in the direction of the arrow, of amodifed form of my improved expanding cavating-bit; and Fig. 16 is a bottom view of such modified form of my improved expanding cavating-bit. A modified form of the screw-joint between the main or pilotboring-bit and its sleeve is shown in Fig. 17, while Fig. 18 is a top-plan view of the screw-shank portion of the pilot-boring-bit removed from the sleeve B.

Referring to the drawings, in the preferred embodiment of my improved cavating apparatus, the end of the drill stem is provided with any common form of bit or drill head, represented in Fig. 13 by the character A. This bit is adapted to be attached to the forward end of a hollow drill stem by any easily detachable means. In

.the present form I have shown a threaded or screw attachment for this purpose. The threaded upper portion of the bit is adapted to be screwed into an interior thread on the drill stem, and may be either cylindrical, as shown in Fig. 13, or somewhattapering, as shown in Fig. 17, the advantage of the tapering form being that a few reverse turns of the drill rod only are necessary to release thefbit from the drill stem. In either case the upper part of the bit is provided with a shoulder, 14, which is adapted, when the bit is tightened 4in place, to contact with the shoulder, 15, on the sleeve, or housing, B, on the drill stem. As an additional means for preventingthe bit from becoming screwed in too tightly, a projection or lug, 14', which tightens into contact with the coperating lug, 15', on the sleeve, B, is used. Provision is thus madefor a' joint between the bit and the drill stem which may be easily released by turning the drill stem in a direction opposite to that used in the operation of the bit. While this is my preferred form of easily releasable connection, other means mayI readily be adopted, as may be clearly seen. The pilot bit, when released, is allowed to remain in the end of the hole.

The cavating o-r enlarging mechanism is contained in a special housing in the drill stem above the bit. This housing is composed of a main section, 6, made up of two parts, the lower part, B, being attached to the upper part by a threaded connection, as shown at 4 in Fig. 4, the lower part, B, being internally threaded to it over the lower/threaded end, 5, of the upper section 6. This section or tube, is i-n turn, threaded to the exterior of the main drillv stem D. In the lower part of the housing, B, two opposite slots, 2, areprovided, through which the blades, 7, of the cavating mechanism may project. These slots are not diametrically opposite, but are off-set or staggered, as shown in Figs. 2, 7 and 8. The upper wall of the slot, 2, is inclined or beveled, as shown at 3, Fig. 1., to furnish a bearing for the blade, 7, when said blade is fully extended. Withinthe housing, B, is the cavating mechanism mounted in'a barrel or tube, F. During the drilling operation this tube is withdrawn somewhat within the main drill stem in the manner shown in Fig. 4. When the drilling operation has been completed and the 4bit detached, the cavating tool is advanced into operative position, as shown particularly in Figs. 1 and 2.

At the upper end of the tube, F, is provided a driving piston head, 11, fitting de .tachably to the tube, F, by means of a downwardly threaded nipple 11. In the center of the disk of the piston, 11, is an upwardly extended collar, 13, around which are mounted the packing piston rings, 12, separated by washer, 14. Above the upper piston ring, 12, is a washer, 15, held in place by a nut, 16, threaded on to the upper end of the upwardly extending collar. The collar, 13, furnishes a bearing for the lift rod, 26, which extends downwardly through the collar and the piston head, 11, to the lower piston head, 18, and is provided at its lower end with an enlargement or head, 27. At the upper end of the said rod,-26, is threaded a cable ring, 27 to which is adapted to be attached the cable, 28, which, while the cavating mechanism is inoperative, serves to support the same in its upper position against the action of the downward current of flushing water. Between these two. piston heads, 18 and 11, and adapted to space the same resiliently apart, is the spiral spring 30, said spring, 30, being seated at its upper end in a grooved washer,

29, and at its lower end in a like washer,

29. The pressure of the helical spring, 30, tends to normally force the lower piston head toward the lower end of the carrier sleeve, F, and the blade, 7, outwardly into cavating position.

To provide a channel for thecurrent of water usually used in this form of drill head to wash away the muck or detritus, a hole is formed Athrough the registering Washers and piston rings, 12, 15; as shown at 17, and-a like channel is formed in the lower piston head.

The reaming blades are mounted within the tube, F, as follows:

Opposite lugs, 19, project downwardly from the lower piston head, 18, furnishing a support for a pivoting spindle or shaft, 20, mounted transversely of the tube in said lugs 19. Said shaft, 20, provides a bearing for intermediate links 21, pivoted at one end to the said shaft 20, and at the other end to the spindle, or shaft, 22, to which is pivotally attached the upper end of the blade, 7. The blades, 7, are pivotally mounted in the tube, F, by means of a shaft, 24, below and in vertical `alinement with the aforesaid shaft, 20. The blades, 7, are elongated, flat bars of steel, provided at their lower ends, 8, with curved or beveled cutting teeth, 7 in one embodiment, although the cutting teeth may have other forms, as shown in Figs. 13 and 14. The upper end, 23, of each of the blades is cut away on the inner side, as at 32, in Figs. 10 and 11, to provide operating space forthe links 21. The upper end of the blade is somewhat recurved and beveled, as shown at 33, for purposes which will now be explained:

When the lower part of the blade is extended through the slot, 2, the upper part of the blade passes outwardly through the inner tube, F, through a slot or passageway, 31, provided therein, and contacts with the outer housing, B. In the said housing, B, to receive the head of the said blade, is arranged a recess, 36, the top of which is beveled to provide a bearing surface, and the lower part of which is recurved so as to provide an upwardly inclined groove for a similarly recurved portion of the head, 23. flo facilitate the withdrawal of the cavating mechanism from the bore after the completion of the cavating operation, the carrier sleeve, F, has the partition, 30, Figs. 1` and 3, forming a division between the head receiving slots, 31, and the slots, 25, of the V-shaped `form in crosssection, shown in Figs. 1 and 2. The upper face of each slot 25 is on the same angle to the axis of the sleeve, as is the upper wall, 3, of each blade slot, 2, of the drill holder sleeve. The blade heads are ofthe shape shown in Figs. 10 and 11, having the link recesses 32. The slide face 33 is of suchan angle that when the blades are thrown out of the slots','2, such bearing face is in abutment with thewall of the pilot bit sleeve, B,

the heads passing through the slots, 31, of

the carrier sleeve, F, and into the annular space at the bottom edge of the main sleeve 6.

The modified form of construction of my improved expanding bore enlarging and cavating bit shown in Figs. 14, 15 and 16, differs from the simpler form shown in the other figures in that the blades 7 are provided with revoluble toothed cutter-Wheels 47, usually of the bevel-gear wheel or conefrustum form shown; which are revolubly supported on short shafts or pins 46. Such wheels are so mounted thatthe bases .will form the cutting edges thereof when rotated to the right with the hands of a watch; and only the wheels have to be renewed, and can be easily kept sharp by grinding. Such wheels are made of very hard and high tempered steels, such as chrome or vanadium ferric alloys, and they work well in the hardest of rock formation such as apatite, etc.

In the operation of this device the well or bore is drilled either downwardly or horizontally inthe ground by means of the pilot bit A. Tdj provide against the caving in of the sides of the drill hole an outer tube, C, is used.v Such tube has at its lower end a drive shoe, G, sharpened somewhat at its lower edge so that it may be driven forward periodically with the progress of the bit. During this drilling operation a stream of water is pumped forcibly downward inside of the drill tube. The said stream is dashed against the bottom of the drill hole and circulated back upwardly outside of the drill stem, carrying with it the crushed material cut away by the drill. In order to provide a proper channel for this upwardly ascending stream, and also at the same time bottom, as shown at 10, 10,` the ratchet teeth facing in the direction of the rotation of the drill rod. In this case it is a clock-wise rotation. The ratchet teeth and grooves cause a stirring up and constant agitation of the muck-laden Water and a swirl in the bore above and below such sleeve E.

When the drilling operation has been completed the drill stem is held firmly downward and rotated in the opposite direction for several turns. The bit is thereby unscrewed and released fromV the drill stem, after which the drill stem is withdrawn slightlv and the reamer blades forced into operative position. This is done by means of fluid pressure exerted downwardly against the piston head, 11, or simply by the force of gravity thereon. The cable. 28, is released for the proper distance, allowing the tube, F, and the `cavating apparatus con- 130 nected therewith to be advanced a proper distance so as to release the blades. In the inoperative position of the cavating mechanism, the downward thrust of the spring, 80, 5, holds the blades iirmly against the sides of the housing, B. When this mechanism is advanced into operative position the blades are rotated by means of the cable, 28, to adapt the blades to register with the slots,

. 2, at which point they are pressed outwardly by the spring until they contact with the beveled upper wall, 3, of the channel, 2. The head of the blade in this movement bears against the upper wall of the recess, 36,

and extends into the operative position therein shown in Fig. 1. The drill stem is then rotated as before and the blades, 7, gradually cut away the earth from the inner periphery of the hole. It is to be understood, of course, that the cavating Iblades do not at once reach their fullest expansion due to their contact with the sides of the bore, but gradually work outwardly as they ream away the sides of the hole.

While the cavation as shown in Fig. 13 is of short length, it is evident that the same may be made in the form of a long cylindrical enlargement of the pilot-bore, made either by withdrawing the casing upward or backward the required distance, after dropping-the pilot-bit; or by driving the pilotbore down the required distance, releasing the pilot-bit at the bottom, and withdrawing the cavating bit up to the casing-shoe; expanding the cavating bit-mechanism, and boring down; this being especially true when the jar or churn form of drill is used; but it is also evident that in this form of rotating bits work may in some formations 4o be done by starting the enlargement or cavation bore at the end or bottom and drawing the drill upward or backward. I claim 1. In a drilling apparatus of the class described, a pilot bit; supporting mechanism for actuating the pilot bit; mechanism carried down with the pilot bitfor enlarging and expanding the pilot bore, without removal of the drilling apparatus, when the proper point is reached; and a support passing out throughy the supportin mechanism normally retaining the expan ing mechanism in a non-operative position within the pilot bit vmechanism support; and means whereby such enlarging mechanism may be forced forward into operative position when the desired oint or stratum is reached.

2. In a drllling'apparatus of the class described, a pilot bit; supporting mechanism for actuating the pilot bit; mechanism carried down with the pilot bit for expanding the pilot bore, without removal of the drilling apparatus, when the proper point is reached; and a supporting cable passing out through the supporting mechanism normally retaining the expanding mechanism in a non-operative position within the pilot bit mechanlsm support, and means whereby Asuch expanding mechanism may be forced forward into operative position when the desired point or stratum is reached.

3. In a drilling apparatus, a pilot bit, a supporting mechanism for actuating said pilot bit, adapted to be rotated in one direction to cut the pilot or main bore, and in the reverse direction in order torelease and abandon the pilot bit in the bottom or end of the main lot bore, mechanism carried in with the pilot bit supporting mechanism for enlarging and expandin the pilot bore 30 without removal of the rilling apparatus,V when the proper point is reached means for bringing the expanding mechanism into operative position upon release of the main pilot bit, whereupon the supporting mechag5 nism may be again rotated for causing enlargement of the main bore above the abandoned bit; and means for withdrawing the enlarging mechanism.

4. In a drillin apparatus, a bit sleeve, a pilot bit secure to the bit sleeve in such manner that by rotating such bit sleeve in the reverse direction to the drillingl rotation the pilot bit will be released from such bit sleeve and abandoned in the bottom of the i bore, and an excavating means for enlarging the pilot bore above the abandoned pilot bit, adapted to be advanced upon the release and abandonment of the pilot bit into the operative position previouslyjoccupied by said bit. v

5. In a drilling apparatus, a drill, a well casing, a combined centering and strengthening sleeve spaced behind the drill for centering the drilling mechanism w1th1n the hole, said sleeve comprising a longitudmal tube adapted to bear throughout its length on the inner surface of the well casing, and having grooves in its outer surface for the purpose described.

- 6. In a device of the character described a drill stem, a drill thereon, a longitudinal centering and strengthening sleeve around saiddrill stem and spaced behind the drill, said sleeve serving to direct the action of the drill, and external grooves in said sleeve to furnish an exit for the flushing water.

7. In a drilling apparatus of the class described, a combined centerin and strengthening sleeve centerin the rill mechanlsm within the bore; a ho low drill rod for supplying fluid under pressure to the oint of drilling, which: fluid carries the drlll muck up by the peripheral wall of the drilling mechanism and by that of the drill rod; the combined centering and strengthening sleeve vbeing provided on its outer periphery with Huid outlet grooves extending longitudinally thereon, riled or spiraled, to assist in the outiio'w of the muck laden fluid stream, such 130 strengthening and centering sleeve being ratcheted at the top and bottom to assist in the agitation and removal of the outward flow of the muck laden fluid.

8. A bore enlarging mechanism comprising a support in the form of a sleeve, or connected sleeves; a cutting blade or blades adapted to enlarge the pilot bore; and means for yieldingly forcing such cutting blade or blades outward through the forward end of the support into the enlarging position when the desired point is reached.

9. A bore enlarging mechanism comprising a support in the form of a sleeve or connected sleeves; a cutting blade or blades adapted to enlarge a main bore; and means for yieldingly forcing such cutting blade or blades forward through the open end of the sleeve into the enlarging position, and for retracting the lcutting blades into small space to permit of the enlarging mechanism being drawn up out of the bore.

10. In an expanding reamer, a cable supported sleeve, reamingblades pivoted resiliently therein, said blades normally held inactive within the line of the sleeve and adapted to be projected into active position by fluid pressure on the sleeve.

11. In a drilling apparatus of the class described, a pilot drill supporting drill sleeve having end slots and adapted to be removably secured to the pilot drill; a main sleeve screwed upon said drill sleeve, an expanding drilling mechanism, cutting blades pivotally mounted therein and adapted to be forced out through the end of the drill sleeve into enlarging position; and means for automatically forcing such blades yieldingly outward through suchend slots upon being brought into registry therewith.

12. In a drilling apparatus of the class described, a pilot drill supporting drill sleeve having end slots and adapted to be removably secured to the pilot drill; a main sleeve screwed upon said drillsleeve; an expanding drilling mechanism, cutting blades adapted to be forced out through the end slots into expanding position by fluid pressure, and means forautomatically forcing such blades yieldingly outward through such end slots upon being brought into registry therewith.

13. In a drilling apparatus of the class described, an expanding reamer comprising a reciprocating sleeve having at the lower end blade receiving slots, a cavating mechanism, comprising a piston reciprocating in the reciprocating sleeve; and a bore expanding blade or blades supported by the reciprocating piston in such manner that when the reciprocating sleeve is drawn upward the expanding blade or blades will be automatically withdrawn into such reciprocating sleeve.

14. In a drilling apparatus of the class described, a hollow cylindrical rod; a drill supporting sleeve secured to the lower end of the rod; a pilot cutting bit secured to the lower end of the drill sleeve in such manner that the same may be disconnected therefrom without withdrawing the drilling apparatus, when the desired length of bore has been attained; and a bore enlarging expandmg drill, adapted to be lowered and expanded into drilling position upon the release of the pilot bit, nor ally supported within the drill supporting s eeve during the pilot boring. v l

15.*In a drilling apparatus of the class descrlbed, a reciprocating sleeve; a piston adapted to reciprocate in the reciprocating sleeve; means normally pressing such piston to the outer open end of the sleeve; and a cutting blade or blades pivotally supported by the s leeve pivotally connected to the reciprocating piston by a link connection, so as to be'thrown out of the reciprocating sleeve and into the expanded .and cutting position when in proper position for expandmg the pilot bore, upon the forcing down or outward of the reciprocating piston.

16.*In a drilling apparatus of the class described, a supporting drill sleeve adapted to carry at the lower end a pilot boring bit or drill; a sleeve reciprocating in the supporting drill sleeve; a secondary bore expanding and cavating mechanism mounted in the reciprocating sleeve; means whereby the reciprocating sleeve may be forced to the bottom of the supporting drill sleeve; and means for forcing the cavating mechanism laterally from the bottom of the reciprocating sleeve, whereby the same is brought into the expanding position, so as to enlarge the pilot bore.

17. In a drilling apparatus of the class described, a supporting drill sleeve adapted to carry at the lower end a pilot-boring bit or drill; a sleeve reciprocating in the supporting drill sleeve; a secondary bore expanding mechanism mounted in the reciprocating sleeve; means whereby the reciproeating sleeve may be forced to the bottom of the supporting drill sleeve; and hydraulic means for forcing the expanding mechanism from the bottom or breast end of the reciprocating sleeve, and expanding the same on such movement of the reciprocating sleeve.

18. In a drilling apparatus of the class described, a supporting drill sleeve slotted at the end adapted to carry at the lower end a pilot drill; a like slotted sleeve reciprocating in the supporting drill sleeve; a secondary bore expanding mechanism mounted in the reciprocating sleeve having an expanding boring blade, or blades; means whereby the reciprocating sleeve may be forced to the bottom of the supporting drill sleeve; and means for forcing the expanding blade or blades into the expanding position so as to enlarge the pilot bore when the supporting drill sleeve is rotated.

19.` In a drilling apparatus of the class described, a supporting drill sleeve slotted at the end, adapted to carry at the lower end a pilot drill; a like slotted sleeve reciprocating in the supporting drill sleeve; a secondary bore expanding mechanism mounted in the reciprocating sleeve having an expanding boring blade, or blades, means whereby the reciprocating sleeve may be forced to the bottom of the supporting drill sleeve; means for rotating the reciprocating sleeve within the supporting drill sleeve so as to bring the blade slot or slots thereof into registry with the slot or slots of the drill` sleeve; and means for then automatically throwing the blade or blades outward through the slot or slots of the supporting drill sleeve.

20. In a drilling apparatus of the class described, a supporting drill sleeve; a sleeve reciprocating in the supporting drill sleeve; a piston reciprocating in the reciprocating sleeve, a. rody passing through the piston and through the head of the reciprocating sleeve; means for supporting the rod in a raised position in the supporting drill sleeve and for lowering the same; a coil-spring surrounding the supporting rod interposed between the reciprocating piston and the head of the reciprocating sleeve, so as to normally force the piston toward the bottom open end of the supporting drill sleeve, and a movable main bore expanding bitor bits, supported below the pisi on in the reciprocating sleeve, thrown into the bore expanding position upon the downward movement of the reciprocating sleeve by the action of the spring upon the piston.

' 21. In a drilling apparatus of the class described, a supporting drill sleeve; a sleeve reciprocating in the supporting drill sleeve; a piston. reclprocating in the reciprocating sleeve, -a rod passing through the piston and through the head of the reciprocating sleeve; means for supporting the rod in a raised position in the supporting drill sleeve and for lowering the same; a coil-spring surrounding the rodI interposed between -the piston and the head of the reciprocating sleeve, so as to normally force the piston toward the bottom open end of the reciproeating sleeve; and a movable cavating bit or bits supported below the piston in the reciprocating sleeve, thrown into the cavating position upon the downward movement of the reciprocating sleeve by the action of the spring upon the piston, the head of the reciprocating sleeve and the piston each having a perforation or perforations to permit of yfluid passing down through the sleeve; and a hydraulic packing, formingy a fluid tight connection between the head of the reciprocating sleeve, and the inner surface of the supporting drill sleeve, whereby upon the release of the supporting means of the. rod, fiuid under pressure while passing freely through the sleeve will force the entire cavating mechanism down and out ol' the supporting drill sleeve into the cavating position.

22. In a drilling apparatus of the class described, a supporting drill sleeve; a sleeve reciprocating in the supporting drill sleeve: a piston reciprocating in the reciprocating sleeve; a rod passing through the piston and through the head of the reciprocating sleeve; means for supporting the rod and reciprocating sleeve in a raised position in the supporting drill sleeve and for lowering the same therein; a coil spring surrounding the rod interposed between the piston and the head of the reciprocating sleeve, so as to normally force the piston toward the bottom open end of the reci'procatingrr sleeve: and a movable cavating bit, or bits supported below the piston in the reciprocating sleeve thrown into the cavating position upon the downward movement of the reciprocating sleeve by the action of the spring upon the piston, such piston and the head of the reciprocating sleeve having each a perforation or perforations to permit of fluid passing down through the sleeve; and a hydraulic packing forming a fluid tight connection between the reciprocating sleeve and theinnersurface ofthe supporting drill sleeve, Awhereby upon the release of the supporting means of the rod fluid under pressure while passing freely through the reciprocating sleeve, will force the entire cavating mechanism down and out of the supporting sleeve into the cavating position; blade slots in the reciprocating sleeve to receive the heads of the cavating blades, normally holding the heads of the blades therein; and like slots in the supporting drill sleeve ending at the upper end in inclined slide faces to permit of the blade 0r blades being retracted into the reciprocating sleeve upon the device being drawn upward in the supporting drill sleeve into which slots the heads of the blades are forced by the action of the coil spring when the heads are brought into registry therewith. j

23. In a drilling apparatus of the class described, a sleeve; a head closing one end of the sleeve; a fluid passage through the head leadi ing to the interior of the sleeve; a piston reciprocating inthe sleeve; a coil spring interposed between the piston and the head, a supporting' rod normally holding the spring in compressionthrough the piston; a cutting blade or blades pivoted to theA sleeve and connected by a pivoted link with the piston; and means for raising and lowering the piston and forrotating the same.

24. In a bore enlarging device, a drill stem, a sleeve thereon, slotted at the forward end, expanding reaming blades supported within the sleeve and adapted to be forced out by a fluid under pressure to the forward end thereof, and a spring for projecting the blades from said slots into active position. l

25. In a device of thekind described,- a rotatable hollow drill stem, a sleeve reciprocatable therein, said sleeve having a slot in the forward end, a supporting member in said sleeve normally held resiliently toward Said forward end, two fbore expanding blades pivoted to said supporting member and forced into expanded position through said slots by the forward movement of said supporting member.

2G. In a bore enlarging device, comprising a housing, an expanding blade or blades mounted on a plunger adapted to be forced forward to project said blades through the forward end of said housing and a toothed conico-frustum cutting wheel for each revolubly mounted on the forward end thereof. 27. In a drilling apparatus of .the class described, a drill stem, a reciprocating sleeve in said drill stem provided with an end slot; a movable member normally pressed toward the open end of the sleeve, means acting to so press the member, and a plurality of movable bore expanding blades secured in the reciprocating sleeve, and forced into the expanding position by the forward movement of the movable member.

28. In a drilling apparatus of the class described, a reciprocating sleeve; an expanding reamer supported resiliently thereby, a head closing one end of the sleeve; a passage through the head leading through the interior of the sleeve to direct the flow of fluid upon the reamer, and a peripheral packing carried by the head.

29. In a drilling apparatus of the class described, a reciprocating sleeve; an expanding reamer connected thereto; a head closing one end of the sleeve; a passage through the head leading through the interior of the sleeve to direct the flow of fluid upon the reamer; and a hydra`ulic ring or rings carried by the head.

30. In a drilling apparatus of the classdescribed, a reciprocating sleeve, a head closing one end of the sleeve; a passage through the head leading to the interior of the sleeve; a piston in the reciprocating sleeve; a coil spring interposed between the piston and the head, a supporting rod normally holding the spring in compression through the piston; and a cutting blade or blades pivoted to the sleeve and connected by a pivoted link connection with the piston.

31. In a drilling apparatus of the class described, a pilot bit supporting sleeve, a bore expanding mechanism adapted to be thrust out into expanding position therefrom, v,reciprocatingly supported within the supporting sleeve; and a pilot bit secured to such supporting sleeve by a screw connectionin such manner that when the required depth has been reached, and the drill is in contact with the `bottom of the bore by rotating the sleeve in reverse direction to the boring rotation, such pilot bit will be released therefrom, whereupon the 4bore expanding mechanism may be brought into operative position.

32. In a drilling apparatus of the classdescribed, a pilot bit supporting sleeve; a lbore enlarging mechanism adapted to be thrust out into boring position therefrom, reciprocatingly supported within the supporting'sleeve; and a pilot bit secured to s uch supporting sleeve by a screw connection, in such manner that when the required point has been reached, and the drill is in contact with the bottom ofthe bore, by rotating the sleeve in reverse direction to the boring rotation, such pilot bit will be released therefrom, whereupon tlie bore expanding mechanism may be brought into operative position; a passage or passages being provided through the expanding mechanism to allow of free passage of iiuid into the bore, when either the pilot bit or the expanding mechanism are in operation.

33. In a drilling apparatus of the class described, a pilot bit, supporting mechanism for actuating the pilot bit; mechanism carried down-with the pilot bit for enlarging the pilot bore, without removal of the drilling apparatus, when the proper point is reached; and a support passing out through the supporting mechanism normally supporting the enlarging mechanism in a nonoperative position within the pilot bit supporting mechanism; and means .whereby such mechanism may be forced into operative position, when the desired point or stratum is reached, by fluid under pressure.

34. In a drilling apparatus of the'class described, a pilot bit; supporting mechanism for actuating the pilot bit; mechanism carried down with the pilot bit for expanding the pilot bore, without removal of the drilling apparatus, when the proper point is reached; and a supporting cable passing out through the supporting mechanism or drill rod normally supporting the expanding mechanism in a non-operative position within the pilot bit supporting mechanism, and means whereby such mechanism may be forced into operative position when the desired point or stratum is reached, such means being operated by a fluid under pressure.

35. In a drilling apparatus of the class described, a pilot bit; supporting mechanism for actuating the pilot bit; mechanism carried down with the pilot bit for. expanding the pilot-bore, without removal 4of the drilling apparatus, when the lproper point is reached; and a supporting ca le passing out through the supporting mechanism or drill rod normally supporting the expanding mechanism in a non-operative position within the pilot bit supporting mechanism and means whereby the expanding mechanism may be forced into operative position when the desired point or stratum is reached; the said mechanism adapted to be wholly withdrawn by said cable from the bore after the completion of the expanding operation.

'36. In a drilling apparatus of the class described, a ilot bit; supporting mechanism or drill rod) for actuating the pilot bit; mechanism carried down with the pilot bit for expanding the pilot bore, without removal of the drilling apparatus, when the proper point is reached; and a supporting cable passing out through the supporting mechanism normally supporting the expanding mechanism in a non-operative position Within the pilot bit supporting mechanism; and means whereby such mechanism may be forced into operative position when the desired point or stratum is reached, said cable removing the mechanism wholly from the bore after the completion of the enlarging operation, by drawing the same out through the hollow supporting drill rod without the removal of such drill rod.

37. In a drilling apparatus of the class described, a drill rod; a pilot drill supported by the drill rod; the bit being releasable from the drill rod; a cavating mechanism for enlarging the bore above the disconnected pilot bit Without removal of the mechanism from the bore; means whereby the enlarging mechanism may be forced into working position upon the release of the pilot bit; and means for withdrawing the enlarging mechanism out of the-bore with- 'out removal of the drill rod. r

38. The hereinbefore described method or rocess of drilling bores, comprising the folerative position by fluid pressure and without removal of the boring mechanism from the bore, enlarging the bore above the disconnected pilot boring bit by rotation of the drill rod in the original direc-tion of rotation.

39. The hereinbefore described method or process of drilling wells, comprising the following steps: (l.) drilling a pilot bore ,to the fluid bearing strata by rotation of the pilot boring drill bit; (2) releasing the pilot boring bit from the drill rod; and raising the drill rod free from the bit; and then (3) forcing an expanding reamer into operative position. by fluid pressure and without removal of the boring mechanism, enlarging the bore above the abandoned and disc-onnected pilot boring bit so as to increase the circumference and consequently the area of the 'percolating wall of the well, b rotation of the drill rod in the original pi ot boring direction.

40. In a device of the class described, a pilot bore drill; a support for such drill; a bore enlarging mechanism normally carried in the support, the drill being secured to its support by a screw joint, provided with means for keeping such joint at all times a loose and easily movable one.

41. In a device of the class described, a hollow drill rod; a pilot bore drill supported by the drill rod, the joint between the two being a maleand female screw tightened by rotation of the drilling rod in the drilllng direction, Vadapted to be released by reverse rotation of the drilling motion when the pilotJboring drill isl in contact with the breast being drilled; and" a ratchet or ratchet-teeth, one upon the endA of the support and the other upon the peripheral flange at the base of-the screw thread vofthe pilot drill co-actingvwith, onev anotherl 1n such manner as to keep the joint between such bit and its support a comparatively loose one.

HOWARD n. HUGHES.-V

Witnesses: v

Il. W. FLETCHER, E. S. BURNMT.