US2580203A - Hammer drill - Google Patents

Description

Dec. 25, 1951 Filed Oct. 28, 1948 E. TOPANELIAN, J R

HAMMER DRILL 4 Sheets-Sheet l IN VEN TOR.

EDWARD T OPBNELIRN, JR-

ATTORNEY.

Dec. 25, 1951 INVENTOR. EDWBRD TOPNELIBNJR- .BY j? //M/Q^ ATT E. TOPANELIAN, JR

Filed Oct. 28. 1948 ORNEY 4 Sheets-Sheet 5 www IN V EN TOR.

BY (5P-P77 De- 25, l951 E. TOPANELIAN, JR

HAMMER DRILL Filed 001'.. 28, 1948 Dec.r 25, 1951 E. TOPANELIAN, JR 2,580,203

HAMMER DRILL Filed oct. 28, 1948 4 sheets-sheet 4 ADS l? lllll INVENTOR. EDWARD TOPANELIN JR /l'vvd-I' /fv ATTORNEY Patented Dec. 25, 1.951

HAMJYIER DRILL Edward Topanelian, Jr., Pittsburgh, Pa., assignor to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware Application October 28, 1948, Serial No. 57,033

(Cl. Z55-4.4)

6 Claims.

This invention relates to well drills and more particularly to a deep well drill cgmbining the advantageous features of rotary and reciprocating drillmechanisms. 1

An object accomplished by my invention is the provision of a well drill which combines in a novel manner the more desirable features of rotary and reciprocating types of drills. A further object accomplished by my invention is the provision of a well drill having increased eiectiveness against hard rock formations. Another object accomplished by my invention is the provision of a drill of the character described, having incorporated therein a huid-operated mechanism for delivering blows to the bit without substantially interrupting the now of fluid through the bit. Still another object accomplished by my invention is the provision of a rotary-reciprocating type well drill of such design that there is no reverse ow to any part of the mechanism tending to carry cuttings from the well into the drill. A still further object accomplished by my invention is the'provision of a well drill of such design that the eiect of hydraulic hammer is diminished, butv advantageously used in some degree to actuate the hammer mechanism. A still further object accomplished by my invention is the provision of an impacttype drill characterized by a valve-operated hammer of such a nature and construction that the hammer may become unseated from thevalve without shock. Other objects appear hereinafter.

, My invention is illustrated by the accompanying drawings and the descriptive matter relating thereto. Referring to the drawings,

Y Fig. 1 is a longitudinal cross section taken through the upper portion of a preferred embodiment of my drill;

Fig. 2 is a longitudinal section taken through the intermediate portion ofthe drill shown in Fig. 1;

Fig. 3 is a longitudinal section taken through thej 1lower portion of the drill shown in Figs. 1 and 2 and the bit attached thereto;

Fig. 4 is a transverse sectional View taken along line 4-4 of Fig. l;

Fig. 5 is a transverse sectional view taken along line 5-5of Fig. 1;

Fig. 6 is a transverse sectional view taken along line 6-6 of Fig. 2;

Fig. 7 is a. transverse sectional view taken along line 1-1 of Fig. 3;

Figs. 8 through 13, inclusive,4 are diagrammatic representations illustrating various phases in the operation of my drill shown in detail in the preceding gures Fig. 14 illustrates an embodiment showing another method ofengagement between hammer I9 and va1ve'24;

Fig. l5 diagrammatieally .illustrates another embodiment of my drill using a casing ring, with the hammer in an intermediate position; and

Fig. 16 is another view of the embodiment shown in Fig. 15, with the hammer engaging the casing ring.

A description of my drill is as follows:

Referring to Fig. l, adapter I serves to connect the drilling assembly with a drill pipe (not shown) and is provided with a central passage 2 for the purpose of introducing drilling uid under pressure into the drill mechanism. Adapter I is screwed into an adapter base 3 which also Yhas a central passage 4 therein to accommodate the pressure fluid. This adapter base is threaded into a drill housing or casing 5 in which are located the operative parts of the drill. The lowermost portion of casing 5 is provided with a bushing 6, shownk in Fig. 3, which serves to retain the internal assembly of the drill as well as to provide a driving torque for a bit-stem 1 slidably disposed -within casing 5 and guided therein by means of replaceable sleeves 8. This driving torque between bushing 6 and bit-stem 1 is accomplished by means of keys 9 inserted in keyways between the two elements, as shown in Figs. 3 and '7, or by other well-known means, such as splines or a hexagonal or square fit between the elements 6 and 1. Bit-stem 1 contains a central passage I0 for the drilling fluid which connects with the central passage II of a bit I2 attached to the end of bit-stem 1. Bit I2 is further provided with passages I3 connecting central passage II with the well bore to facilitate the removal of cuttings and chips therefrom by means of ilushing action of the drilling fluid. The upper portion of bit-stem 1 is threadedly connected to an anvil I 4, shown in Fig. 2, which is also Slidably disposed within casing 5 and guided therein by means of a replaceable sleeve I5. Parts 1 and I4 are suitably disposed to accommodate the base Ilia of an eduction tube I6 which is sealed and retained between the two members by a compressible washer I1, and may be keyed to anvil I4 if desired. This eduction tube I6, having a central passage I8 connecting with passage I 0 in bit-stem 1, extends through anvil I4 and thereabove into a considerable portion of casing 5. A reciprocable ram or hammer I9, suitably disposed from casing 5 to form annular passage 2l and guided therein by means of lugs 20 welded to the hammer, as shown in Figs. 2 and 6, is provided to produce percussive blows upon anvil I4 which in turn transmits the resulting shocks through the remainder of the drill mechanism to the drill bit I2. Both hammer and anvil may be provided with hardened bushing inserts to resist wear at the point of impact between the vtwo elements. A central passage 22 is providedwithin hammer I9 connecting with pas'- sage i8 in eduction tube IB to provide a further path for the operating uid. Anvil I4` is provided with a recessed portion 23 adapted to accommodate a valve 24 which is slidably disposed on eduction tube I6. The annular surface o f anvil I4 exposed to hammer lblows is providedY with passages 25 to form a connecting path for the pressure fluid in passages .2l to recess 23 -in the anvil. Valve 24 is provided with a shoulder` 26 adapted to engage the bottom of hammer I9 when the body of valve 24 has sufficiently entered the hammer bore inwhich it has a closesliding t. ,The shoulder 26 of valve 24 is further providedwith slots 2l and a taper clearance 2S at the lower end of the valve so that pressure uid within recess 23 may be communicated to beneathV the valve'to'providean actuating force therefor. The upward vmovement o 'f valve 24 on eduction tube I6 Iis'limited by means of a helical spring 25J disposed -abut 'the leduction tube and retained thereonbymeans of locking nuts 35. However, a valve stop, such as a tubular valve stop extending over the upper portion of eduction tube I6 and beneathspring 29, could be advantageously used in addition to limit upward movement of valve 24. At the upper end of hammer I9, shown in Fig. 1, fluid communication is provided between the inside and outside thereof by means of holes`3I, shown in Figs. l and 5, so that in the position of the parts as shown, pressure fluid will flow through the central passage 22 of hammer I9 and out through the bit. The upper portion of hammer I9 is received by a cylinder tube 32 which is closed at its top by -cap 33 sealed thereto, as shown'in Figs. l and 4. Tube 32 is suspended in casing 5 by means of lugs 33a welded to cylinder 32 and held against shoulder 34 of the casing by adapter base 3 screwed against cap 33. Cylinder 32' is suitably disposed from casing 5 by means of the aforementioned lugs 33a as well as lugs 35 welded to the lower portion thereof suchthat annular passage 36 is formed between the cylinder and'ca'sing. Cap 33 is shaped to form passages 31 connecting passage-36 with central passage 4 of the Yadapter base 3. Thelower portion of cylinder 32 vis provided with a replaceable bushing 38 to accommodate hammer I3 and form a good sealing but freely sliding lit therefor, so thatupon situated several feet above the bottom of the hole. In this position, bit-stem 'I and anvil I4 together with the attached parts will be in their lowermost positions as retained by bushing E. Hammer I9 resting on, anvil I4 will also be in f its lowermost position so that holes 3l near the top of the hammer will be uncovered. In other 4 Words, all parts will .be in the positions as sh-own in Figs. 1, 2 and 3 of the drawings. It is usually desirable to rotate in when a new bit has been attached to insure lthat the hole is full size, and to flush out sediment and cuttings which may have settled to the bottom while bits were being charles@- 'Ihis iS accomplished merely by establishing the circulation of drilling fluid downward through the vcentral passage of the ,drill stem and rotating the bit while it is lowered through the last few feet to the bottom of the ,well bpre. During this rotating in process, uid will be circulated through , passages 2, 4, 31,36, 3I22, I8,IQ`, II and out through passages I3 of thebit returning up the hole outside of theY drill housing v5. It should be noted that no now occurs between hammer I9, valve 24 and anvil I4 because the passages provided by holes 3I will suiiiciently bypass enough pressure iluld to the well bore. Sinceall the passageways are open, no pressure differentialexists," and accordingly valve `2,'4 :and hammer I9 will notlbe-'a'ctuated at 'this stage'of operation. Thus, hammering will not take place to endanger the drill pipe or other parts as the drill islowered. This stage of operation is `shown diagrammatically in FigfS.

In ligs.v 8 to 13 the"arrows indicate the action ofthe pressure liiuid in operatingthe device. Upon' continuing to'lower' themechanism while rotating-casing 5,"thus`produc`in`g rotation of bit-stem 'Iand bit I2, the noseorcutting edgeof'bit I2 will eventually touch the bottom of the hole. Further lowering ofthe drill pipe and attached parts will 'then cause changes in the-relative positions between-casing 5 and the internal parts 'I, I4 and I9. Since cyllnder32 is integral with casing .5,"the cylinder will eventually close olf passages 3| from fluid ilow. '1 -he partsl will essentiallyl then be in` the positions as lshown diagrammatically in Fig59.' Due to the fact that there i'sno immediate 'outlet for the fluid being supplied Vunder pressure from surface pumps, the pressure will build up 'wlthin'passage 2| and will'be transmitted through passages 25 and recess'23a`nd slo-ts'v2'l to beneath valve 24. The uppervs'urface 'of valve L24 is eXposed'to a pressure substantially Vequivalent to the static head of "the 'iluid in the wellbore at the depth of the Valve, since rthe uppersurface of `the valve is afforded communication with the 'well bore through passages 22, I8, I0, II and I3. There is, therefore', va :differential pressure existing across valve 24. Because the pressure beneath' the valve fis `greater than that exerted on its 'uppensurfaceg the valvewill rise within the bore' of hammer I'Siuntil shoulder 26 of/ the valve engages the lower surface of .the hammer. The parts'iwillthen be inthe positions as shown diagrammatically in Fig. 10. The continued application of. vfluid pressure .beneatlithe valve and hammerA will raise valve 24 and hammer lI9 vas a unit. This is due to the fact that a differentialA pressure alsoexists acro'ssfthe hammer, the upper surface of hammerl beingin communication with the well bore through centralpassage 22 of. the hammer vand passages I 8,v III, Il and I3, through which passages the fluid inside the hammer-'L19 andfcylin'der V32 is discharged to the annular space outside the drillf It is apparer'it that 'a'large area-is-providedat the ybase of the hammer jfor initial acceleration ofthe hammer upward; This' iirst stage of acceleration con-7 tinues until the parts reach the relative positions as shown vdiagrammatically in Eig. ll, at which-time'V` the'upward 'travel of valve 24 will' be arrested by the compression of spring 29. However, a pressure diiferential still exists across the hammer and iiuid pressure will still be applied. to the lower surface thereof, although it is apparent that the effective hammer area acted upon by such pressure is reduced because valve 24 is now restrained from further upward movement. The hammer will therefore continue to move upward, and this second stage of acceleration will be of such a degree that the momentum of the hammer will continue to carry it upward and away from valve 24 until it is decelerated and returned downward 4by the forces of gravity and spring 39. The relative positions of the parts after hammer I9 has become disengaged from valve 24 and immediately before descent of the hammer are shown in Fig. 12. Referring to Fig. 12, it can be seen that a free ow of pressure fluid will take place around the base of the hammer into the upper end of eduction tube I6, and thence through the remaining lower parts outward into the' well bore. The internal pressure exerted on the upper and lower surfaces of both hammer I9 and Valve 24 will be approximately equalized so that the forces o-f gravity and ysprings 39 and 29 will be permitted toaccelerate hammer I9 and Valve 24 downward, respectively. Valve 24, having already had its upward movement arrested, is quickly returned to its lowermost position as shown in Fig. 13, while the upward momentum of hammer I9 is overcome by the action of spring 39 (and gravity) and is then returned to its lowermost position. The downward acceleration of hammer I9 and the momentum resulting therefrom will produce a considerable impact upon anvil I4 when the hammer comes in contact therewith, and this impact will be transmitted through the remaining lower parts of the drill t0 the cutting edge of Ibit I2, resulting in a percussive blow against the formation at the bottom of the hole. The slight overlap shown in Fig. 2 between hammer I9 and valve 24 is not sufficient to materially retard the hammer or cushion the percussive blow because valve 24 represents in fact an almost instantaneously-yielding outlet and relief for pressure fluid. The uid pressure in the region 23 begins to rise as soon as hammer I9 overlaps with valve 24, and this early pressure rise is helpful in accelerating valve 24 upward and in developing the necessary pressure for the upward acceleration of the hammer for a new cycle of operation so that a rap-id succession of Iblows exerted against the formation being drilled will result. Due to the fact that the entire drill is slowly rota-ted, the various percussive blows exerted on the well formation will be made at points angularly displaced from one another by several degrees so that the drill bit will chip out' the formation between successive points of impact. Flushing fluid from the drill will continuously be discharged from the bit into the well bore to carry the chips to the surface of the well. Continuous operation of the drill will therefore completely remove material from the bottom of the hole and result in advance of the drill through the formation.

Certain modifications which may be made are deserving of specific mention. It will be noted that the lower inside portion of cap 33, shown in Fig.. 1, is provided withv a tapped blind hole 33h. This hole permits the attachment of space r` discs (not shown) within cylinder I9 above spring 39, if desired, to increase the spring pressure. The tapped hole 33e onuthe upper side of cap 33 is provided simply for pulling purposes, i. e., so thatv cap 33 may conveniently be removed when disassembling the mechanism. It is important to note that, as explained below, both spring 29 and spring 39 may be eliminated from the drill Without rendering the drill inoperative. With respect to the elimination of spring 39, it has been found by experimental observation that the force of gravity alone is sufficient to decelerate hammer I9 after it has been raised by iiuid pressure and is sufficient also to return it to strike a blow on anvil I4 with substantial force. However, to speed up the lreturn of hammer I9 and increase the number of blows per minute, spring 39 has been provided so that hammer I9 may be more quickly decelerated and returned. Spring 39 may be a partial or bumper spring within cylinder 32 or a full length spring as shown in Fig. 1, with or without initial compression when installed. With respect to the eliminationv of spring 29, tests have shown that under certain .conditions the force of gravity alone is sufficient to effect return of valve 24 after it has become elevated and hammer I9v has broken away therefrom. However, to assure proper return of valve 24 in heavy drilling fluids, spring 29 has been provided. Spring 29 may also be a partial or bumper spring so as to give merely initial return impetus to the valve after it has been raised to theupper limit of its travel, or spring 29 may be a full length spring as shown in Fig. 2.

It should be noted that the means provided for engagement between valve 24 and hammer I9 may be variously modified. For example, valve 24 may be so constructed as to engage a shoulder Isa located within hammer I9, as shown in Fig. 14. not be recessed to accommodate the valve but may be flat, as shown. The base of hammer I9 would then be providedwith slots I9b to permit operating fluid under pressure to circulate beneath a taper provided on the lowerv end of valve 24 when hammer I9 rests on anvil I4, so that valve 24 may be actuated by operating fluid. f In another embodiment (not shown) no shoulder may be provided, either in hammer I9 or onvalve 24, so that valve 24 will reach the end of its travel before the hammer is forced upward, following which the hammer will be lifted upwalrd from the valve in one stage of acceleration on y.

Another embodiment of my drill is shown schematically in Figs. 15 and 16 wherein I provide an annular projection or casing'ring 4D Within casing 5 so that the outer periphery of the ring forms a continuous' seal with the casing. The ring may be secured to the casing by Iboring holes through the casing and welding to the ring inside the hole, or by other suitable means. An outer shoulder I9c is provided on hammer I9 so that when the hammer becomes fully elevated,

as in Fig. 16, a seal will be provided against operating fluid under pressure entering the drill above the hammer. Howeven'the ring is provided with suitable running clearances over the shoulder of the hammer, and the inner periphery of the ring is tapered so that the upper end of the hammer can be readily guided therethrough from below during assembly. When the hammer is not fully elevated, as in the position shown in Fig. 15, sufficient clearance exists between the upper portion of the hammer and the easing ring toassure free circulation of operating fluid to the base of the hammer. The purpose of the Acasing-ring is to utilize the hydraulic force In such an embodiment, the anvil I4 needv 7, of the .operating duid to limit the'upward travel of the hammer, and further, `to accelerate it downward. Thus, vthe .use .of a--casing ring cuts down on the time lost when the hammer is decelerated on` its upward stroke, and at the same time reduces excess fluid loss through the eduction tube occurring during the interval that the hammer was being decelerated and returned. The net eiect is to increase the operating frequency of the drill. In one series of tests the operating .frequency was increased from 400 strokes perminute to over 700 strokes per minute by ,simply .adding a casing ring as described hereinabove.

The sequence of operations of the drill is not substantially affected lby the use of a casing ring. When hammer I9 becomes sufliciently elevated to become disengaged from valve 24, shoulder tec .on hammer .i9 will form a seal against casing ring l4B, resulting in a sudden increase in .pressure above the ring and hammer shoulder. The system-will then resemble .the action of a piston in 4a, cylinder, and this pressure will arrest 'the upward travel of hammer t9 as well as provide considerable hydraulic force to accelerate it downward. When shoulder |90 engages casing ring 4o theflow of fluid through the rest of the drill will .be momentarily cut oir. In contrast to this, .it isrecalled that in the other embodiments of my drill where no casing ring is provided there is a free .flow of fluid over hammer i9 and out through eduction tube I6 during the entire time that hammer I9 -is disengaged from valve 24. However, this interruption of fluid flow when employing a casing ring is so slight and takes place so quickly that .it amounts to only `a iiicker in the iiuid discharge from the bit. Furthermore, there is suicient compressibility in the fluid column so that, considered with the limited rate of shock-wave propagation in the iiuid, no vexcessive hydraulic hammer results by using thecasing ring. In fact, over-all operation is more smooth when the ring is used. In addition, over-all operating pressure may be somewhat lower because the required rate of fluid iiow is reduced by the casing ring.

In vthe.embodiment of Figs. 15 and '16 there is shown an annular projection on the casing in the shape of an annulus or ringiw. Itis to be understoodfhowever that such shape is by way of illustration only and that any means may be used having a shape so as to cooperate with a corresponding shape on the hammer i9 to interrupt the'iiow'of operating fluid to the base of the hammer when elevated.

One of the advantages of my drill is that iiuid flow through the bit is never substantially Vinter-- rupted. even while delivering blows to the bit; thus permitting maximum utilization of the effects of iiushing iiuid. As described above, when a casing ring is used there is a slight interruption in fluid flow, but this occurs for only a fraction of each cycle. Another advantage is that direct communication of uid pressure is'v provided between the well bore and the hammer actuating cylinder through the bit, so that Vall uid pumped down the drill stem is effective in removing cuttings. The upward acceleration of the hammer is effected in two stages, the first stage being that during which the valve 24 and the hammer I9 are raised together and the second stage being the Subsequent one during which only the'hamrner I9 is raised. The rst stage, .due to the larger `pressure area of both hammer .and valve, provides a relatively large impetus to the hammer at-the start'of its. upward motion with .minimum pressure rise in the operating fluid. Transition .to the second ystage of hammer acceleration, which is somewhat smaller than thev rst stage, occurs with minimum shock at the moment the valve 24A pulls away from the hammer i9 since no large differential pressure exists across the valve at the moment its movement is arrested and it leaves its seat in the hammer.v The alternative method of operating my drill without springs, wherein the maximum effectof gravity is utilized, is advantageous Where the use of springs is considered undesirable. It is to be noted that fluid ow throughthe mechanism is everywhere `unidirectional and at no time is there any reversal of fluid flow in any portionof the drill mechanism which would tend to carry cuttings into the drill and produce operational failures. This advantageous feature is made possibie because the power fluid supplies fmake-up fluid behind the hammer in the actuating cylinder 32 so that make-up is not required from the well bore, and further, .because continuous flow is maintained through the bit in an outward direction. A still further advantage lies in the automatic relief provided for hydraulic hammer. and the beneficial utilization of kpressure rise resulting therefrom to effe-ct initial operation of valve 24 and hammer i9. Another advantage is that the stroke of the hammer may be varied by adjusting the operation and travel of the hammer-actuating valve 24, e. g. by adjusting the position of the spring-retaining nuts, changing springs, inserting `valve stops of diierent lengths or valves of different lengths orfchanging the location of the valve shoulder, etc. or length of .eduction tube I 6.

It will be apparent to those skilled in the art who have familiarized themselves with this disclosure of my invention that numerousmodifications in addition to those hereinabove set forth may be made without departing from the spirit of the invention. Furthermore. the preferred embodiments specifically described herein are intended to be merely illustrative of my invention, and in no manner should they be considered as limitations thereof or as limiting the scope of the appended .claims'hereinafter made.

What I claim is:

l. In a huid-operated deep well drill, the combination comprising a tubular casing, an .inverted cup-like cylinder longitudinally mounted in said casing, means affording operating fluid access to the lower end of said cylinder, an elongate annular ram slidably disposed -in and sealed against the inside of said cylinder and having a longitudinal central passage, an annuiar .anvil block inthe path of said ram slidably disposed in and sealed against the Vinside of said casing below the open end of said cylinder, a downward extension rigidly connected to said anvil block and adapted to be rotated by rotation of said casing and tol carry a drilling tool, said extension having a longitudinal central passage connecting with the interior of saidanvil block, an eduction tube extending upward from said anvil block into the interior of said ram and having a central passage connecting with the interior of said anvil block, an annular valve slidably disposed outside of and sealed against said eduction tube and adapted to seal the central passage of said ram when in engagement therewith, means permitting operating fluid access to the bottom'face of said valve,.and an abutment carried on the outer surface of said eduction tube and spaced from said anvil block by an amount which limits the upward vtravel of said valve to an amount which is smaller than the upward travel of said ram.

2. In a duid-operated deep well drill, the combination comprising a tubular casing, an inverted cup-like cylinder longitudinally mounted in said casing, means aiording operating uid access to the lower end of said cylinder, an elongate annular ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal central passage, a compression spring retained in the interior of said cylinder with its upper end against the upper end of said cylinder and its lower end providing a return for said ram upon being elevated, an annular anvil block in the path of said ram slidably disposed in and sealed against the inside of said casing below the open end of said cylinder, a downward extension rigidly connected to said anvill block and adapted to be rotated by rotation of said casing and to carry a drilling tool, said extension having a longitudinal central passage connecting with the interior of said anvil block, an eduction tube extending upward from said anvil block into the interior of said ram and having a central pas sage connecting with the interior of said anvil block, an annular valve slidably disposed outside of and sealed against said eduction tube and adapted to seal the central passage of said ram when in engagement therewith, means permitting operating uid access to the bottom face of said valve, and an abutment carried on the outer surface of said eduction tube and spaced .Ll

from said anvil block by an amount which limits the upward travel of said valve to an amount which is smaller than the upward travel of said ram.

3. In a duid-operated deep well drill, the combination comprising a tubular casing, an inverted cup-like cylinder longitudinally mounted in said casing, means affording operating fluid access to the lower end of said cylinder, an elongate annular ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal central passage, an annular anvil block in the path of said ram slidably disposed in and sealed against the inside of said casing below the open end of said cylinder, a downward extension rigidly connected to said anvil block and adapted to be rotated by rotation of said casing and to carry a drilling tool, said extension having a longitudinal central passage connecting with the interior of said anvil block, an

eduction tube extending upward from said anvil block into the interior of said ram and having a central passage connecting with the interior of said anvil block, an annular valve slidably disposed outside of and sealed against said eduction tube and adapted to seal the central passage of said ram when in engagement therewith,y

means permitting operating uid access to the bottom face of said valve, an exterior abutment carried on the upper end of said eduction tube, and a compression spring retained on the exterior of said eduction tube with its. upper end against said abutment and its lower end providing a return for said valve upon being elevated, said abutment and said spring being dimensioned to limit the upward travel of said valve to an amount which is smaller than the upward travel of said ram.

4. In a duid-operated deep well drill, the combination comprising a tubular casing, an inverted cup-like cylinder longitudinally mounted in said casing, means affording operating fluid access to the lower end of said cylinder, an elongate annular ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal central passage and a passage through the wall connecting the interior and exterior of said hammer, an annular anvil block in the path of said ram slidably disposed in and sealed against the inside of said casing below the open end of said cylinder, a downward extension rigidly connected to said anvil block and adapted to be rotated by rotation of said casing and to carry a drilling tool, said extension having a longitudinal central passage connecting with the interior of said anvil block, an eduction tube extending upward from said anvil block into the interior of said ram and having a central passage connecting with the interior of said anvil block, an annular valve slidably disposed outside of and sealed against said eduction tube and adapted to seal the central passage of said ram when in engagement therewith, means permitting operating uid access to the bottom face of said valve, and an abutment carried on the outer surface of said eduction tube and spaced from said anvil block by an amount which limits the upward travel of said valve to an amount which is smaller than the upward travel of said ram.

5. In a fluid-operated deep well drill, the combination comprising a tubular casing, an inverted cup-like cylinder longitudinally mounted in said casing, means affording operating fluid access to the lower end of said cylinder, an elongate annular ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal central passage, a constriction on the inner surface of said casing, an enlargement on the outer surface of said ram cooperating with said constriction whereby when said ram is elevated the operating uid is confined thereabove and a downward impetus imparted to said ram, an annular anvil block in the path of said ram slidably disposed in and sealed against the inside of said casing below the open end of said cylinder, a downward extension rigidly connected to said anvil block and adapted to be rotated by rotation of said casing and to carry a drilling tool, said extension having a longitudinal central passage connecting with the interior of said anvil block, an eduction tube extending upward from said anvil block into the interior of said ram and having a central passage connecting with the interior of said anvil block, an annular valve slidably disposed outside of and sealed against said eduction tube and adapted to seal the central passage of said ram when in engagement therewith, means permitting operating fluid access to the bottom face of said valve, and an abutment carried on the outer surface of said eduction tube and spaced from said anvil block by an amount which limits the upward travel of said valve to an amount which is smaller than the upward travel of said ram.

6. In a duid-operated deep well drill, the combination comprising a tubular casing, an inverted cup-like cylinder longitudinally mounted in said casing, means aording operating fluid access to the lower end of said cylinder, an elongate annular ram slidably disposed in and sealed against the inside of said cylinder and having a longitudinal central passage, an annular anvil block in the path of said ram slidably disposed 11 in and sealed against the inside of said casing. below the open end of-saidt cylinder, a. downward extension rigidly connected' to said anvil. block and adapted to be rotated by rotation of said casing and tocarry a drilling tool, said .extension having a longitudinal central. passage'connected with the interior of said anvil block, an eduction tube extending upward from said anvil block into the interior of said ram and having a cen,- tral passage connecting with, the interior of said anvil block, an annular valve sldablyV disposed outside.. of and sealed against said eduction tube and adapted to partially penetrate and seal the lower end of said ram, means,permitting operating iiuid access to the bottom face. ofzsaidrvalve, andV an abutment carried. onv the outer surface REFERENCES CITED The Vfollowing references are of i record ini the leof` this patent:

UNITED` STATES PATENTS' Number Name Date.

1,065,298 Curre11. June 17, 19.13` 1,861,042 Zublin May 31, 1932 1,892,517 Pennington Dee. 2.7, 1932 2,388,741.

Hays Nov. 13, 19145

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