US2823013A - Apparatus for dry drilling of bore holes - Google Patents

Description

Feb. 11, 1958 A. P. c. STENUICK 2,323,013

APPARATUS FOR DRY DRILLING OF BORE HOLES Filed Sept. 19, 1952 2 s ets-Sheet 1 ANDRE PIERRE CAMILLE STENdIcK- Feb. 11, 1958 A. P. c. STENUICK APPARATUS FOR DRY DRILLING OF BORE HOLES 2 Sheets-Sheet 2 Filed Sept. 19, 1952 4 a m I,

ANDRE PIE RR; can 'LLE Srsu ulck United States Patent APPARATUS FOR DRY DRILLING OF BORE HOLES Andr Pierre Camille Stenuick, Eveque, Belgium Application September 19, 1952, Serial No. 310,508

Claims priority, application Belgium September 26, 1951 3 Claims. (Cl. 2553) This invention relates to drilling and boring equipment, and more particularly to apparatus for drilling bore holes of large diameter and great depth.

In the drilling of bore holes of large diameter and great depth, several methods have been employed in the past,

to wit:

(1) Rotary drilling which yields bore holes of great depth but is slow and very costly.

(2) Boring with the bit which utilizes a tool of large diameter driven in by a succession of violent thrusts.

The rate of advance is slow and, when the rock is hard,

the cutting edge of the bit is blunted rapidly so that the operation wears out a large number of tools.

(3) Boring with long borer or jumper of large diameter wherein the jumper bit is driven by a pneumatic or electrical hammer striking light blows at a very rapid rate. This method permits sinking the hole at considerable speed, but does not permit reaching depths sufiicient for purposes of modern rock penetration; a depth of 12 meters is at present considered the maximum obtainable in the current practice of this process. I

In all these methods, the apparatus which directly controls the bore-hole-drilling operation is located in the open, above ground.

Up to now large drilling depths could not be attained because the mass of the jumper bit and its accessories absorbed almost by itself the blows struck by the hammer, with the result that the impact ultimately conveyed to the rock'to be disintegrated was very much reduced. On the other hand, the supply of air through the interior of the joint rods supporting the jumper bit, which is needed for expelling the debris deriving from the drilling operation and collecting at the bottom of the hole, is insufficient for an efiective removal of this debris. Lastly, boring to great depths necessitates an assembly of bars or rods which is extremely fragile at every joint because of the transmission of impacts over the entire length of the rod assembly.

It is the principal object of the invention to eliminate these drawbacks and to provide improved drilling equipment well adapted for bore holes of large diameters and greatdepth, and capable of operating at high speed, low cost and increased efiiciency. I

.Otherobjects, and the manner in which the same are attained, will become apparent as this specification proceeds.

According to one of its aspects, the invention contemplates disposing the percussion apparatus or hammer right above the bit so that it is introduced into the bore hole and de'scendstherein as the work progresses, in such manner that it advances immediately after the bitwhich. it actuates and is located at all times in close proximity to the very bottom of the bore hole.

This descent or sinking is accomplished by the successive addition of coupled tubes the weight of which can be counterbalanced, for example, by counterweights.

In the drawing accompanying this specification and forming part thereof, one embodiment of the invention is illustrated diagrammatically by way of example.

.HCC

In the drawing:

Fig. 1 is a schematic side view, partly in vertical section, of drilling equipment according to the invention;

Fig. 2 shows, in vertical section, the lower extremity of the equipment shown in Fig. 1, drawn to a larger scale;

Fig. 3 shows, in vertical section, a hammer-and-bit assembly according to the invention; and

Fig. 4 is a bottom view of the assembly shown in Fig. 3.

According to this invention the percussion device is progressively introduced into the deepening bore hole and has a diameter smaller than the largest diameter of the bit. The device penetrates into the bore hole directly following the bit 15 which it actuates, and the casing of the device is rigidly connected with a first tube 4' to which may be added one or more extension tubes by suitable joints.

When the hammer or ram 20 is of the pneumatically driven type, as more particularly disclosed herein, the compressed air required for its actuation is supplied through the interior of the tubes supporting the percussion device. This percussion device is equipped, in 31C- cordance with a feature of this invention, with an air distribution system of known construction whereby the exhaust air is intermittently discharged through the boring bit 15, e. g. by way of a central channel 24 as illustrated in Fig. 2 or near the periphery of the bit between its cutting edges as shown in Figs. 3 and 4. This air, accordingly, serves to evacuate from the bore hole 40 the dust and debris accumulating at its bottom in the course of the disintegration of the soil material by the percussive action of the bit.

In the embodiment of Figs. 1 and 2 a carriage 8 is arranged for displacement on the ground S. This carriage' is provided with a vertical rail 9 slidably supporting a frame member 10 which is integral with a gear box 11; the latter is coupled via a transmission 14 to a depending tube 4' extending downwardly toward the casing 13 of the percussion device. The gear box 11 encloses mechanism known per se for rotating the tube 4' with the casing 13, the ram 20 and the bit 15 which latter is mounted on a short stem 2'.

A cable 16 is secured to frame member 10 and passes over a pulley 17 mounted on top of the rail 9; the free end 39 of the cable 16 is provided with means for supporting a counterweight 18. This counterweight is so chosen that it balances the successive increase in weight of the coupled tubes when one or more extensions are added to tube 4. Evidently, the Weights to be added to counterweight 18 should correspond to the weight of the added extension tube or tubes in order to provide a percussion tool which exerts a constant static pressure, as indicated by arrow 42, upon the bottom of the hole 40. Compressed air is supplied to the ram 20 within cylinder 13 by way of tube 4' from a suitable source not shown.

In Fig. 2 the piston or ram 20 is provided with a piston rod 21 arranged to act on the rod-like integral extension 22 of bit 15. The distributor for the operating air has been indicated diagrammatically at 23. In operation, the arr 1s admitted to the interior of cylinder 13 alternately above and below the ram, in a manner more fully described hereinafter, and is intermittently expelled through channel 24 to clear out fragments of solid material from the bore hole as itleaves the latter through the annular clearance provided between the wall of the hole and the outer surface of the cylinder 13.

In Figs. 3 and 4 there is shown a cylinder head 26 which is rigid with tube 4 and extends downwardly toward a junction with cylinder 13 onto which it is screwed. The interior of this cylinder accommodates the bit 15 which in this instance, as best seen in Fig. 4, is equipped with four blades 27.

The distributor, here designated 29, comprises a disk 30 adapted alternately to open and to close a passage 31 establishing a path between the space 33 above ram 20 and an annular chamber 34 receiving compressed air from the tube 4. A conduit 35 establishes communication between the space 33 below the ram 20 and the space 50 above disk 39 which in turn communicates with the annular distributor chamber 34. This conduit 35 extends from an opening 53, located in the upper part of distributor 29, to another opening 5'4 located directly above the drill bit 15.

In order that the exhaust air after operating the ram may be utilized in the cleaning of the bore hole and in the evacuation of debris, exhaust conduits 36 are provided in the wall of the cylinder 13 which extend downwardly and have their exit orifices 41 between the blades 27 of the bit 15. Apertures 37 establish communication between the space 32 below the ram 20 and the conduits 36.

The disk 3d rests loosely on a ring-shaped collar 51. A passage 52 connects the central distributor chamber 50, located above disk 30, with the opening 53 in the cylinder shell.

With this arrangement the evacuation of debris from hole 4% is efiected by successive, sudden expansions of compressed air which is expelled by the ram after having actuated the same. The mode of operation is as follows:

As the ram 2th rises, the space 32 above it is connected with the opening 53, located above disk 30, and with the annular distributor chamber 34. Passage 31, located under the disk Ed, is shut oil by the latter. Because of the higher pressure prevailing in space 32, the ram 20 is driven further upwardly and, toward the end of its stroke, uncovers the apertures 37 which permits the air present under the ram to escape by way of these apertures and conduits 36.

Upon completion of this upward stroke, the pressure of the air compressed by the ram 20 in space 33 will exceed the pressure prevailing above disk 39. As a result, the disk is raised and space 33 is thereby connected with the annular chamber 34. The force of gravity and the higher pressure obtaining in space 33 will drive the ram 2' forcefully toward the bit 15 and the air contained in space 32 will be ejected through apertures 37 and conduits 36.

As the ram reaches the end of its downward stroke, it covers the apertures 37 and compresses the air contained in space 32 until the pressure present therein exceeds the pressure prevailing below disk 36. This disk is then depressed and comes to rest on the ring-shaped collar 51 which supports it. The ram then strikes the bit 15 and causes a deepening of the bore hole, whereupon the pressure in chamber 50 acts upon the lower surface of the ram 213 whose upper face is then under atmospheric pressure as the air above it is allowed to escape through the uncovered upper set of apertures 37. The difference in pressure causes the ram to rise again and the cycle is repeated.

The air forced under pressure through the apertures 37 and the conduits 36, at various stages of the cycle just described, will blow and eject from the drilled bore hole the scrap produced by the action of the bit. The pressure increments occurring whenever the piston or ram reaches its top and bottom positionswill give rise to strong pulsations in the duct system 13, 4', thus further facilitating the ejection of waste. These pulsations are propagated through tube 4' and its extensions so as to dislodge any fragments that may have settled there, in this manner preventing any blocking of the air inlet passages.

Tests have shown that the herein described method of removing debris, grindings, chips and dust from the bottom of the bfife hole into the atmosphere is much more efiicient than the continuous blowing of scavenger air through the bore hole and that it permits attaining boring depths of as much as fifty meters.

5 wish to be understood that I do not desire to limit the invention to the exact details of construction, design, method and operation shown and described inasmuch as numerous modifications, within the scope of the appended claims, will be apparent to persons skilled in the art.

} claim:

1. A drilling machine comprising an air pump, tubing adapted to be lowered into a bore hole and intercommunicating with said pump, and a drill bit projecting from tubing, said tubing including a tubular end portion receiving the inner part of said bit and defining on its interior a cylinder chamber, said end portion having a series of bores parallel to the axis of said chamber and offset from said axis open at the bottom adjacent the cutting part of the bit, each bore having a passage for intercommunicating interiorly with said chamber above said inner part of said bit, a piston reciprocable in said chamber between a lower position, wherein it covers said passages and makes impact with said inner part of said bit, and an upper position wherein it clears said passages, and means including an upper conduit delivering air above said piston, a lower conduit delivering an below said piston at a point near the lower position thereof and valve means between said conduits for reciprocating said piston, whereby between each two succeeding impacts of said piston with said bit air will be driven twice from said chamber into said bores, the first time during the descent of the piston before it covers said passages, and the sec- 0nd time during the ascent of the piston after it clears said passages.

2. A drilling machine as claimed in claim 1, wherein said outer part of said drill bit includes intersecting edgecarrying arms angularly spaced apart from each other, said bores having their open bottoms disposed between said arms, whereby air will be delivered into the spaces between said arms for directing an air blast towards said edges.

3. A drilling machine as claimed in claim 1, wherein the axes of all of said bores are arranged along the periphery of a circle about the axis of said chamber, the diameter of said circle being slightly smaller than the width of said outer drill bit part, whereby the air will be directed in parallel streams eccentrically of the drill bit center towards the outer regions of the drill bit edges.

References Cited in the file of this patent UNITED STATES PATENTS 1,408,975 Black Mar. 7, 1922 1,845,074 Billstrom Feb. 16, 1932 1,881,258 Bayles Oct. 4, 1932 1,981,475 V Smith Nov; 20, 1934 2,033,527 Kitching e MarQlO, 1936 2,085,279 Tautenhahn June 29, 1937 2,241,712 McNamara May 13, 1941 2,359,147 Merten Sept. 26, 1944 2,620,162 Pennington Dec. 2, 1952 2,661,928 Topanelian Dec. 8, 1953 2,665,115 Bassinger Jan. 5, 1954 OTHER REFERENCES High Drilling Rates Reported for Steam'-Powered Percussion Drill, pages 167-168, Pit & Quarry, 1953, May edition.

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