US3883177A - Diamond drill and rock fragment excavation device - Google Patents

Abstract

In a preferred embodiment of the invention, there is provided a subterranean cavern excavated by conventional methods and with conventional support structures and floor, with vertically extending shafts extending downwardly thereto for the removal of mining rock debree, and from the floor of the cavern there extend downwardly shaft-drilling downwardly facing diamond drill faces rotatably drillable of deep shafts into hard lithosphere earth and there extend between distal downwardly located terminal ends of parallel shafts of the downwardly facing diamond drill faces spaced apart from one-another a predetermined distance a laterally extending substantially horizontal tubular rotatable diamond drill having the drill bits of the tubular rotatable diamond drill arranged substantially helically along the tubular surface of the outer face of the tubular drill, there being defined within the downwardly extending drill shafts and within the bevel gear arrangment and within the horizontal tubular rotatable diamond drill a coolant flow path and structure defining the same, and there being apertures along the diamond drill bit outer surface of the horizontal tubular rotatable diamond drill for passage of the coolant therethrough to environment of the drilling diamond drill bits thereof, and the entire downwardly extending drills and horizontal drills being encased within a steam or other coolant-entrapment casing substantially totally segregating coolant vapor from environmental spaces for human being workers within the passages of the subterranean passages, and by conventional mechanisms the diamond drills being lowerable during the drilling operation as deeper drilling proceeds. There is also provided laterally horizontally extending conveyor belt mechanisms and rock fragment-removal mechanism for retrieving rock fragment to the conveyor belt which in turn delivers the same to collection vessels for conveyance to earth surface locations.

Description

United States Patent [191 Baciu [451 May 13, 1975 [54] DIAMOND DRILL AND ROCK FRAGMENT EXCAVATION DEVICE [76] Inventor: Petru C. Baciu, 48-20 48th St.,

Woodside, Queens, NY. 11377 [22] Filed: Jan. 23, 1974 [21] Appl. No.: 435,697

2,563,913 8/1951 Binney 175/330 X 3,424,254 1/1969 Huff 175/17 3,460,867 8/1969 Cameron et al. 299/2' 3,612,193 10/1971 Hirata 175/91 Primary ExaminerErnest R. Purser [57] ABSTRACT In a preferred embodiment of the invention, there is provided a subterranean cavern excavated by conventional methods and with conventional support structures and floor, with vertically extending shafts extending downwardly thereto for the removal of mining rock debree, and from the floor of the cavern there extend downwardly shaft-drilling downwardly facing diamond drill faces rotatably drillable of deep shafts into hard lithosphere earth and there extend between distal downwardly located terminal ends of parallel shafts of the downwardly facing diamond drill faces spaced apart from one-another a predetermined distance a laterally extending substantially horizontal tubular rotatable diamond drill having the drill bits of the tubular rotatable diamond drill arranged substantially helically along the tubular surface of the outer face of the tubular drill, there being defined within the downwardly extending drill shafts and within the bevel gear arrangment and within the horizontal tubular rotatable diamond drill a coolant flow path and structure defining the same, and there being apertures along the diamond drill bit outer surface of the horizontal tubular rotatable diamond drill for passage of the coolant therethrough to environment of the drilling diamond drill bits thereof, and the entire downwardly extending drills and horizontal drills being encased within a steam or other coolant-entrapment casing substantially totally segregating coolant vapor from environmental spaces for human being workers within the passages of the subterranean passages, and by conventional mechanisms the diamond drills being lowerable during the drilling operation as deeper drilling proceeds. There is also provided laterally horizontally ex tending conveyor belt mechanisms and rock fragmentremoval mechanism for retrieving rock fragment to the conveyor belt which in turn delivers the same to collection vessels for conveyance to earth surface 10- cations.

DIAMOND DRILL AND ROCK FRAGMENT EXCAVATION DEVICE This invention is directed to the drilling and excavation of rock deep in the lithosphere and below, by novel drilling and evacuation devices of the present invention.

BACKGROUND TO THE INVENTION Naturally occuring in nature, as one goes beneath the earths upper surface, there eventually is encountered deeper earth in the form of very hot and very hard rock, with superificial earth layers thereabove as a cover in the form of sedimentary rocks which have different composition and crystaline structure and are typically cold rock soft in nature as compared to the deeper rock. Conventional drilling and mining drilling equipment is directed to and designed solely for and is effective solely in the drilling of sedimentary rocks, for the drilling of sedimentary rocks of many different physical characteristics as the crust of the earth; for such crust of the earth drilling there are accordingly many specialized new types of equipment for permitting mankind to penetrate into the earths depths. However, the excavation operation in hot and hard rocks of. and below the lithosphere constitutes one of the most formidable problems in the mining field today, particularly with the ever increasing importance of arriving at new sources of energy that might be associated with the mining of such depths.

The continuous development of science and technical demands require new solutions in all fields, together with the practical elements of simplicity, low cost of material, low cost of operation, and speed of operation, for thereby providing an economical solution.

The hot and very hard rocks of and below the lithosphere have very high density and a temperature much higher than the surrounding shallower earths crust, the temperature of these deep rocks rising up to about 1200F, or more, depending upon the age of the rock. Prior to the present invention, there has not been produced efficiently effective types of equipment able to produce mined narrow excavated chambers by drilling to penetrate these hot, hard rocks. The urgent industrial needs of society to build such narrow and long and deeper chambers demand as immediate, simple, and economical equipment and method producing such a mined excavation by a novel approach which will permit the excavation of such hot and hard rock without the physical presence of human laborers, and without polluting the hydrosphere, lythosphere, or atmosphere, and without complicated and/or costly equipment and without requiring normally complicated and expensive cooling systems and equipment normally very difficult to build and normally very costly and therefore totally uneconomical in the drilling of such chambers by any heretofore conventional approach.

In the drilling at deep depths below the earth in the presence of these elevated temperatures and in the drilling of such hard rock, there clearly has to be effective cooling of the drill bits.

However, a problem with the use of coolant at these depths includes the ready vaporization of most conventional coolants at these depths, particularly if water is utilized as an inexpensive coolant. In the presence of steam so-produced, clearly there could be hazard to life. Also, there is the problem of removal of rock fragment when the coolant has vaporized and therefore does not avail itself as a vehicle to carry-away the rock fragments.

Accordingly, it may be now better appreciated the magnitude of the complexities of any efforts to design an equipment and process for the removal of and excavation of these deep hot and hard rock by drilling.

SUMMARY OF THE INVENTION Accordingly, objects of the present invention include the overcoming of one or more difficulties and problems of the type discussed above, and the fulfilling of one or more needs of the type discussed above.

Other objects become apparent from the preceding and following disclosure.

One or more objects of the present invention are obtained by the invention as defined herein.

Broadly the invention achieves the object(s) by the employment of particularly designed diamond drill equipment together with specially designed deep cavern structures, together with a conveying system and equipment therefor for the transport of the rock fragments from the drilled areas.

More particularly the equipment and system include one or more upright downwardly extending supports supporting a laterally extending normally horizontal tubular drill having the drill diamond bits mounted preferably helically along the outer tubular surface with the tubular element being rotatable as the tubular element is permitted to press downwardly to engage and grind away the rock, there being apertures within the face of the tubular element through which coolant is passed from within the tube to prevent excessive heating-up of the diamond drill bits which it should be noted are grinding solely on the lower half of a revolution since the upper half of the revolution is not in contact with the rock. Preferably the support is at each end of the tubular element diamond drill and each support includes at its lower end a terminal drill face downwardly facing also of diamond drill bits with the downwardly facing drill bits being rotatably ground downwardly into the hard hot rock. It is important that the coolant flow be sufficiently great as to flow away and/or blowaway the rock fragments to a point to which they may be gathered mechanically and transported mechanically from the site of drilling. Although there are possible other mechanisms, in a preferred embodiment of the invention, a large mass-bucket or box device having bottom flap(s) which flip upwardly by any convenient mechanism such as for example by the pressure of the bucket or box pressing downwardly into fluid slurry or mud to push upwardly the flap(s) to thereby fill within the bucket or box inner space defined by the walls thereof, whereupon the flaps become pressed downwardly to a closed state as the bucket or box is raised mechanically as by cables, the contents of the bucket or box thereby being raised with the bucket or box to thus be conveyed to a convenient point. In a preferred system, a horizontally extending floored cavern has been excavated in low-temperature harder rock of the earth with conventional methods of excavation and support within the cavern, and from this subterranean cavity the deep drilling is performed. Accordingly there is provided a conveyor belt upon which the filled bucket or box is emptied such that the contents of fragmentary rock is conveyed to a larger vessel which is thereafter utilized to complete the trip of the rock fragments to the earths surface. Preferably the cabled bucket and/or box system and conveyor belt and vessel lift are each and all mechanically carried on in the ab sence of the actual presence of human beings within the operating space by virtue of the presence of a segre= gating casing which is mounted flushly upon the upper cavern floor adjacent the point at which the vertical downwardly facing drills and at which the horizontally extending tubular drill cut a crevice-like slot downwardly into the hot hard rock, whereby the steam produced is totally isolated from the areas of control by the workers, the steam being channeled upward through chimney structures of the casing.

Although water is a preferred coolant of the present operation because of low cost thereof, other coolants that might be desired and/or conventional are within the contemplation of the present invention, including one or more high boiling organic liquid coolants, for example of the type normally employed with nuclear reactors.

The diamond bits and mounting structure(s) therefor will be of the desired and/or conventional type(s).

In a preferred embodiment of the invention, spaced apart downwardly extending rotary shafts provide for plug drilling-out as well as provide for the support of the horizontally extending tubular element diamond drill extending therebetween and supported between and by the spaced-apart upright drills, and the upright drills each preferably rotate in drill fashion, and extend through a bevel gear apparatus secured operatively to the horizontal tubular drill with operative connection with the bevel gear mechanism by each of the upright drill and the horizontal tubular drill such that the rotary motion of the upright drive and support shaft is imparted to the tubular diamond drill element to rotate it such that the helically arranged diamond bits along the outer tubular surface of the tubular drill rotatably drill into the hot hard rock therebeneath.

The invention may be better understood by making reference to the following Figures.

THE FIGURES FIG. 1 illustrates a side cross-sectional view as taken through apartially drilled excavation employing the preferred embodiments of the present invention, illustrating the upper excavated cavern extending horizontally and the elongated slots and holes drilled downwardly therefrom, together with typical preferred rock fragment transporting equipment and earth surface derrick drilling towers.

FIG. 2 illustrates an elevation plan view of an installation at earth surface of an embodiment typically as illustrated in FIG. 1.

FIG. 3 illustrates an elevation plan view of the installation of FIG. 2 as it would appear devoid of the structures mounted on the surface of the earth.

FIG. 4 illustrates a view substantially corresponding to that of FIG. 1, after completion of the drilling thereof and after removal of the drilling equipment, along FIG. 3 lines 4-4.

FIG. 5 illustrates a view as taken along lines 5-5 of FIG. 4, in an in-part view.

FIG. 6 illustrates an in-part view in side crosssectional view of the upright and horizontal tubular drills of FIG. 1.

FIG. 7 illustrates an in-part enlarged side view as taken along lines 7-7 of FIG. 8.

FIG. 8 illustrates a side cross-sectional view in in -part view as taken along lines 88 of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 through 8 all relate to the same basic illustra' tion as best shown in its entirety in FIG. 1, some of the Figures being merely special views. Accordingly the invention is hereafter described in general with regard to all Figures.

In cold or hot hard rock of and below the lithosphere, excavation may be made without the need of reinforcing structures that are essential in conventional drilling and mining to prevent collapse of the wall; in the hot and hard rock to which this invention is directed, the rock is self supporting. Accordingly, it is necessary to build by conventional methods a shaft to the hot and hard rock, and according to a preferred embodiment of the invention to build by conventional methods and supports the tunnel extending horizontally at the base of the shaft 30 for the purpose of connecting consecutive wells 30a and the shaft, the tunnel being also for the facilitation of transport of excavated rock fragments toward the earths surface from the drilled hardrock chambers in accord with the present invention. Also, the tunnel makes possible the connection of consecutive upright downwardly facing diamond drills operatively with the bevel gearing and the interconnecting horizontally extending tubular drill elements.

Self-supporting casing 30a is provided for the drilling well 3012.

The shaft 30 will be of conventional construction and materials built by conventional methods, and will include passenger elevator 49, elevator 14 for hoisting rock fragments by motor 45, cables 39 for hoisting collection vessel 11 enclosed within conduit 29 extending upwardly within the shaft 30, cable 43 for hoisting the elevator 14, automatic measurement instruments and control lines (not illustrated) of conventional types together with conventional pressurized air conduits, light lines, drinking water lines and safety equipment and the like are are conventional. Tunnel 31 is excavated at the base of shaft 30 extending in opposite lateral directions horizontally built by conventional method at a size best suited for the operations to be performed at any given point therein, such as the connection of the tubular upright diamond drills 3 and the horizontal interconnectiong tubular diamond drills 6 connected by bevel gears 5 for the driving thereof from the rotation drills 3. Also extending horizontally within the tunnel 31 is the conveyor 12, together with an associated hopper typically including an archimedy-type screw conveyor extending from the hopper 13 to the elevator 14 to be filled. Casing 28 serves to channel upwardly the steam 27 in a segregated state from worker personnel spaces of the tunnel 31.

The excavation installation with diamonds as described above is achieved by two or more drilling bit apparatuses depending on the length of the excavated chambers, but may consist of a single unit if desirable.

With particular reference to FIG. 1, the composite parts illustrated, for example, include the derrick drilling towers l equiped with swivels 2, and other conventional materials such as lifting hooks, cables, cranes, etc., and rotary tables 8, and engines 7 for driving the rotary tables 8, upright drills 3 with the lower portion connected bevel connecting portion 33 connected optrated a diamond cutting'block includingthe portion 33 having water passage and exit therefor through the continuing passages of the bevel gears and horizontal drill 6. It may be seen that the cutting downwardly directed diamond bit face of drill 4 is of sufficient diameter or breadth as to permit easy insertion in the drilled passage the bevel gears'S and casing 9.

It is necessary to" mention that at the bevel gear mechanism 5 and casing 9 one or both will include obviously a convention type plug of the coolant flow conduit in the direction in which there is absent any further tubular drill at each of opposite terminal end portions of an installation, in order to prevent uncontrolled flow and loss of coolant.

FIG. 6 illustrates ih'enlarged in-part view in crosssection the operational relationship of the conical bevel interacting gears 5 having steps 36 thereof, and the horizontal diamond tubular drills passage 35 and associated apertures37 for coolant flow to the diamond bit cutting surfaces and the diamond cutting bits 38. This coolant water exiting through apertures 37 also serves to facilitate removal of the rock fragments from the.

surface of and vicinity of the cutting diamond bits and to produce a plastic mass or mud loadable therby into the collection vessel 11. The water is fed from an outside reservoir source 17, and after passage through apertures 37 in the vicinity of collection vessels 11 when lowered evaporates and is vented to atmosphere in the segregating casing 28; there are water return pipes 24 however for water to clarifying tank 25, and water bypass conduit (conventional in nature) 26 between tank 25 and reservoir 17, and reservoir outlet and pump inlet pipe 18 and pump 19 and pump outlet pipe 20, and branch feed pipes 21 connected to the coolant passage of drill tubular pipe 3 for feeding coolant through the lower portion 33 coolant passage into thelower drill 4 (conventional in nature) through apertures in its lower face andinto the horizontal tubular drill passage 35. The coolant water serves to cool the drilling driving tubes as ,well as the drill diamond bits.

The water in its cooling and lubrication circuit absorbs the heat generated from the friction of the drilling pipes and the diamond bits with surrounding rock as well as the rocks latent heat. If the water sources are not sufficient for necessary cooling, then the water vapors 27 can be condensed and introduced again in the water-cooling circuit. During the initial period at the the excavation when the hard rock is not hot enough for the evaporation of the water from within the chambers, the evacuation of the water and mud from the chambers 32 is done with the mud pump 23 placed in the tunnel 31, mud suction conduit 22 being directed downwardly to the mud source, and pump outlet 24 leading upwardly, and leading to the clarifying tank 25, etc..

ling diamond bits is principally effected by the elevator vessels It, by elevator cables 39, pulleys 40, electric winches 41 placed on the earths surface, and the like.

In FIGS. 1 and 8, the elevator vessel 11 and its hinged bottom openable upwardly as botton 42 are viewable. The hinged bottom 42 of the elevator vessel 11 opens during the downward penetration of the elevator vessel into the plastic mud of rock fragments, and closes due eratively to drive bevel gearsS typically within a casing The evacuation of the excavated material by the drilto gravity and downward weight of contents upon the raising'of the vessel 11 by the supporting cables.

In FIGS. 1 through 4 and 7 and 8, there is viewable the entire system fromdifferentviews, such as of tunnel 31, wells 30a, shaft 30, steam segregating casing 28, steam exhaust conduit 29, and condensor 29a feeding into receiver 17 by conduits 29b. 7

By desirable and/or conventional means already well known to technology, all of this activity will be watched and controlled automatically and/or manually principally from a central control room 48 and panel including typical pressure, temperature, power, and television sensors and the like, with appropriate electronic circuitries therefor and for the automatic control of the activities to be carried on by the cables, conveyors, drills, pumps, etc.

During the advancement of the excavation in both sedimentary and hard rocks, there are provided the necessary drilling tubular drill pipes and pieces and replacement bits, casings, and the like. The typically would be provided and outside warehouse for such, as warehouse 50.

OPERATION On the ground there is set up rotary tables 8 with engines 7, with the tables having their upright support aligned with the respective shafts 30, with the drive engines 7, with an equal number of drilling pipes 3 spaced apart equally along the ground surface, with the support drilling tower for each, as towers 1. The swivels 2 are connectedfor the water, and then the water is introduced into the drilling pipe 3 each equiped with the downwardly directed drilling bit 4. Drilling of upper shaft 30, wells' 3a and excavating of the tunnel 31 is conducted in accord with known mining procedures and methods employing standard material and parts. Below the floor of the cavern tunnel 31, drilling proceeds utilizing the system already described above, utilizing these specially designed drilling bit combinations and system, for the drilling of the hot and hard rock. The bit 4 is aligned coaxially with the axis of the drill tube 3. Then the operation is automatically started as follows.

The engines 7 begins driving the rotary tables 8 and thereby driving the drilling pipes 3 and intimate diamond bits 4, and through the bevel gear mechanism 5 the tubular diamond cutting bit 6 is driven in a horizontal position to cut downwardly a slot into the hard hot rock.

The coolant water and/or steam quickly produced produces a mud plastic mass which is pumped upwardly by pump 23 by mud inlet 22 and pump outlet 24. The elevator vessels 11 load and transport mud-like rock fragments upwardly and clumps the same onto conveyor belt 12 which delivers the same to the hopper with the archimedytype screw conveyor into transport vessel(s) 14 for conveyance to ground level. The vessel 11 is dumped by inverting action of cables 39a and 39b as shown in FIG. 8. The tower shaft structure 46 by pulley mechanisms 44 and cables 43 lift the elevator collection vessel 14 upwardly for delivery of its cargo (as typically by a downwardly opening bottom not illustrated of any conventional type) into a conveyor train hopper car 15 which transports on tracks 47 to a storage bin 16 for excavated rock fragments. During the initial period when the mud pumps are most necessary, all elevators 11 must work continually because the speed of the water circulation in the chambers 32 does not assure the mud evacuation of all the chips by the diamond bits. This eliminates substantially the possibility of any blocking of the installation by plugging. During the working operation of the excavation with the diamond drills, it is necessary to watch very closely to ascertain that the automatic system should maintain the speed and the advance of all the drilling pipes 3 at the same value and perfect synchronizing operation. This condition is necessary in order to obtain the effect synchronized cutting by both the vertical bit 4 and the tubular horizontal bit 6 such that the bevel gears and casing 9 do not become blocked. The vertically extending drill tubes 3 in the sedimentary rocks as well as in the zone of the hard rock are constructed and operated by conventional means except the preferred coolant passages in the drilling face 4 thereof. Drill-pipe centering-sleeves will be mounted in spaced vertical relationships to one-another along the drilled channel 32a.

The mining works, the equipment, the geological conditions (characteristics) of the hot and hard rock, shown in the above combined technology, allows a new method of high efficiency which can produce narrow chamber, long and deep, channels, trenches, and galleries in the hot and hard rocks, offering this way a new weapon for an inexpensive and simple way of excavation even in the most unbelievable circumstances.

In FIG. 4, one can see the whole excavation in the sedimentary rocks zone as well as the hot and hard rock. Narrow chamber 32 and 32a resulting from the downward drilling by the horizontal drills 6 and vertical drill 4 are defined by substantially smooth and clean self-supporting walls, of the hot hard rock, complying with all necessary technical requirements.

There preferably is a linear (coaxial) relationship between consective alternately located horizontal drill tube 6.

It is within the scope and spirit of the invention to make modifications, and substitution of equvalents within ordinary skill of an artisan in this field.

I claim:

1. A rock drilling device comprising in combination: a tubular element having inner and outer tubular surfaces and defining a plurality of coolant-flow apertures through the tubular walls of the tubular element with the apertures defining a coolant flow path from within the tubular element to laterally exterior thereof, the apertures extending substantially radially outwardly from the longitudinally axially extending tubular coolant flow path within the tubular element, there being diamond cutting bits arranged along the outer tubular surfaces with the apertures substantially adjacent the diamond cutting bits, and bevel gear means and drive shaft means with the drive shaft means extending along its longitudinal axial axis at an angle laterally relative to the tubular elements longitudinally axially extending axis and the shaft means being operatively connected through the intermediate bevel gear means for revolvable with and fixedly secured to a terminal end of the longitudinally extending drive shaft means with the diamond drilling face extending in a direction substantially transverse to the tubular elements longitudinally axially extending axis, the diamond drilling face having an area of drilling effectiveness at least as great as a cross-sectional area of the drive shaft means, and

a second drive shaft means and a second bevel gear means and a second diamond drilling face each mounted at an opposite end of the tubular element operatively substantially the same as the other drive shaft means, the other bevel gear means and the other diamond drilling face.

3. The rock drilling device of claim 2, and vaporizable coolant and tubular means for channeling the coolant to the tubular element, and in which the tubular means for the coolant extends concentrically within at least one of the drive shaft means and through the bevel gear means operatively to communicate with the tubular elements coolant flow path.

4. The rock drilling device of claim 3, and power drive means for driving the drive shaft means, and extension support means for supporting the drive shaft means and for extending the same downwardly as drilling proceeds, and encasing means for segregating vaporized coolant from surrounding human beinginhabitable environment and for channeling the vaporized coolant to a location away from the drilling site,

and rock fragment-removal means for collecting rock fragments from rock-drilled sites and conveying the same to a rock elimination location away from the drilling site, and substantially horizontally extending subterranean passage-defining cavern means defining space and horizontal floor structure and conveyor means extending substantially horizontally along the cavern means space, the conveyor means being for receiving rock fragments from the rock fragmentremoval vessels, and including removal vessel means with removal vessels transportable of rock fragments contained therein from the cavern means to a location at substantially the earths surface.

Claims (4)

1. A rock drilling device comprising in combination: a tubular element having inner and outer tubular surfaces and defining a plurality of coolant-flow apertures through the tubular walls of the tubular element with the apertures defining a coolant flow path from within the tubular element to laterally exterior thereof, the apertures extending substantially radially outwardly from the longitudinally axially extending tubular coolant flow path within the tubular element, there being diamond cutting bits arranged along the outer tubular surfaces with the apertures substantially adjacent the diamond cutting bits, and bevel gear means and drive shaft means with the drive shaft means extending along its longitudinal axial axis at an angle laterally relative to the tubular element''s longitudinally axially extending axis and the shaft means being operatively connected through the intermediate bevel gear means for driving rotatably the tubular element around the tubular element''s longitudinally axially extending axis as a result of force transmitted by the drive shaft means to and through the bevel gear means, and the tubular element being supportable by the bevel gear means and the bevel gear means being supportable by the drive shaft means.

2. The rock drilling device of claim 1, in which said diamond cutting bits are arranged substantially helically in a longitudinally axially extending direction along the outer tubular surfaces, and a plug drilling shaft means including a diamond drilling face rotatably revolvable with and fixedly secured to a terminal end of the longitudinally extending drive shaft means with the diamond drilling face extending in a direction substantially transverse to the tubular element''s longitudinally axially extending axis, the diamond drilling face having an area of drilling effectiveness at least as great as a cross-sectional area of the drive shaft means, and a second drive shaft means and a second bevel gear means and a second diamond drilling face each mounted at an opposite end of the tubular element operatively substantially the same as the other drive shaft means, the other bevel gear means and the other diamond drilling face.

3. The rock drilling device of claim 2, and vaporizable coolant and tubular means for channeling the coolant to the tubular element, and in which the tubular means for the coolant extends concentrically within at least one of the drive shaft means and through the bevel gear means operatively to communicate with the tubular element''s coolant flow path.

4. The rock drilling device of claim 3, and power drive means for driving the drive shaft means, and extension support means for supporting the drive shaft means and for extending the same downwardly as drilling proceeds, and encasing means for segregating vaporized coolant from surrounding human being-inhabitable environment and for channeling the vaporized coolant to a location away from the drilling site, and rock fragment-removal means for collecting rock fragments from rock-drilled sites and conveying the same to a rock elimination location away from the drilling site, and substantially horizontally extending Subterranean passage-defining cavern means defining space and horizontal floor structure and conveyor means extending substantially horizontally along the cavern means'' space, the conveyor means being for receiving rock fragments from the rock fragment-removal vessels, and including removal vessel means with removal vessels transportable of rock fragments contained therein from the cavern means to a location at substantially the earth''s surface.

Images