US3887236A - Apparatus and method for cutting and breaking rock - Google Patents

Apparatus and method for cutting and breaking rock Download PDF

Info

Publication number
US3887236A
US3887236A US37038873A US3887236A US 3887236 A US3887236 A US 3887236A US 37038873 A US37038873 A US 37038873A US 3887236 A US3887236 A US 3887236A
Authority
US
United States
Prior art keywords
breaking
mass
reaction
rock
wheel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
James G Patrick
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bechtel Group Inc
Original Assignee
Bechtel International Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bechtel International Corp filed Critical Bechtel International Corp
Priority to US37038873 priority Critical patent/US3887236A/en
Application granted granted Critical
Publication of US3887236A publication Critical patent/US3887236A/en
Assigned to BECHTEL GROUP, INC., 50 BEALE ST., SAN FRANCISCO, CA 94105 A CORP. OF DE reassignment BECHTEL GROUP, INC., 50 BEALE ST., SAN FRANCISCO, CA 94105 A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BECHTEL INVESTMENTS, INC., A CORP. OF NV
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/02Core bits
    • E21B10/04Core bits with core destroying means
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/02Core bits
    • E21B10/06Roller core bits
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21BEARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B25/00Apparatus for obtaining or removing undisturbed cores, e.g. core barrels, core extractors
    • E21B25/10Formed core retaining or severing means
    • EFIXED CONSTRUCTIONS
    • E21EARTH DRILLING; MINING
    • E21DSHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D9/00Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
    • E21D9/10Making by using boring or cutting machines
    • E21D9/11Making by using boring or cutting machines with a rotary drilling-head cutting simultaneously the whole cross-section, i.e. full-face machines

Abstract

A continuous mining machine for excavating an in-place mass of rock or other material having echeloned concentric cutter heads that remove rock or other material from annular concentric grooves, leaving bands of undisturbed material between the grooves cantilevered from the in-place mass, and a breaking device carried by the machine adjacent and behind the cutter head for breaking the undisturbed bands from the mass with an intermittent or continuous breaking force.

Description

United States Patent [191 Patrick June 3,1975
[ APPARATUS AND METHOD FOR CUTTING AND BREAKING ROCK [75] Inventor: James G. Patrick, Hillsborough,
Calif.
{73] Assignee: Bechtel International Corporation,
San Francisco, Calif.
[22] Filed: June 15, 1973 [21] Appl. No.: 370,388
[52] US. Cl. 299/10; 175/57; 175/250;
[51] Int. Cl E2lb 9/18; 1321c 41/00 [58] Field of Search 299/10, 18, 86, 90; 175/404, 332, 333, 57, 250
[56] Reierences Cited UNITED STATES PATENTS Schmidt 299/86 X 1,723,330 8/1929 Cross et a1. 175/333 X 3,050,292 8/1962 Newton et a1. 299/86 3,288,532 11/1966 Carver 299/86 X Primary ExaminerErnest R. Purser [57] ABSTRACT A continuous mining machine for excavating an inplace mass of rock or other material having echeloned concentric cutter heads that remove rock or other material from annular concentric grooves, leaving bands of undisturbed material between the grooves cantilevered from the in-place mass, and a breaking device carried by the machine adjacent and behind the cutter head for breaking the undisturbed bands from the mass with an intermittent 'or continuous breaking force.
8 Claims, 12 Drawing Figures FIB-JD- FIE--11 APPARATUS AND METHOD FOR CUTTING AND BREAKING ROCK BACKGROUND OF THE INVENTION Utilities located in the flat central area of the United States do not have available economic sites for conventional pumped storage and. therefore. are seriously considering underground pumped storage. Also, because of environmental objections. other utilities are actively investigating underground pumped storage even though conventional hill and valley sites are available. The key to economic underground pumped stor age is the cost of excavating the underground cavity. The present invention provides a device for rapidly excavating a suitable cavity in rock at low cost.
Other applications of the invention include all types of tunne s such as those for railroads, highways, water and other utilities, as well as all forms of underground excavations such as in the mining industry.
The demand for larger diameter and longer tunnels has challenged the engineering and construction industry to devise less costly methods for driving tunnels. One answer to this challenge has been the development of the mechanical mole. These machines are setting new records in driving rates. Furthermore, because they produce a smooth bore with no shattering of the surrounding rock, other costs such as tunnel supports are reduced. Mechanical moles have operated in many types of rock. Among the many factors influencing the economics of mechanical moles are the rate of forward progress achieved and the effectiveness of the cutters. Present mechanical mole machines operate on the principle of cutting or cutting and chipping small pieces of rock from the full area at the face of the tunnel being excavated. As the rock being excavated becomes harder, more energy is required, forward progress decreases and the additional wear on the cutters per unit of advance increases cost.
SUMMARY OF THE INVENTION Unlike the mechanical moles now in operation, the method or principle of my invention is to out only a small percentage 35%) of the full area at the face of the tunnel being excavated in the in-place mass of rock or other material and to remove the remainder by intermittently breaking from the rock mass pieces of rock which will vary in size but could be one cubic foot in volume or larger. The concept is based on providing narrow concentric cutter heads which by cutting action remove the rock from annular concentric grooves leaving bands of undisturbed rock between the removed concentric grooves. The bands of undisturbed rock are broken from the inplace mass by a breaking force acting in a radial direction or one otherwise transverse to the direction of excavation. The broken pieces of rock will be of various size depending upon the strength and natural jointing structure of the rock being excavated. As the amount of rock to be removed by cutting (or cutting and chipping) action represents only a small percentage of the full area at the face of the tunnel, less energy will be consumed by the cutting as compared to mechanical moles now in operation. Conversely, forward progress will increase substantially.
The breaking force may be provided, for example, by hydraulically operated cylinders mounted within the concentric cutter heads, or, alternatively, by fixed wheels. By utilizing leverage, a large breaking force breaks pieces of rock off the concentric bands of inplace rock, which are cantilevered from the in-place rock mass.
The reaction to the breaking force is carried by the solid mass of in-place rock. This is accomplished by echeloning the concentric cutter heads, which cut the concentric grooves, for example, such that the outer cutter heads are forward of the adjacent inner cutter heads. This arrangement of concentric bands of undisturbed rock cantilevered from the in-place rock mass and echeloned. such that the outer bands are forward of the adjacent inner in-place bands, allows the breaking means, for instance. to consist of two close coupled wheels actuated by a hydraulic cylinder through a lever arm. An outward breaking force is provided by a narrow wheel having a rounded surface such that a concentrated force can be exerted. An inward reaction force is carried by a wider wheel having a flat surface such that the reaction force is distributed to the solid mass of the inner in-place rock. As the major portion of the rock breaking force (as well as the reaction force) is applied to in-place rock, the stress within the cutter head assembly is minimized. Also, the contacts between the rock and the two wheels are rolling contacts absorbing minimum energy. The rock breaking force is applied intermittently on the several bands of rock at approximate intervals of one foot of forward progress without interruption of the cutting process. The broken rock falls between the arms of the cutter support wheel to the floor of the tunnel for removal.
An alternative fixed beveled wheel breaking device operates on the same principle, but the breaking action is continuous and not intermittent.
The principal object of the invention is to provide a mechanical excavating device for rapidly excavating an in-place mass of rock or other material at low cost and with a minimum expenditure of energy.
Other objects and advantages will become apparent upon consideration of the following description of a specific embodiment of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view ofa mechanical mole utilizing my invention ready for operation in a tunnel;
FIG. 2 is a rear view of the device shown in FIG. 1;
FIG. 3 is a side elevation partly in section through the device shown in FIG. 1;
FIG. 3A is a side elevation partly in section through a modified form of the device;
FIG. 4 is a section taken through one of the cutting parts of the device showing the cutter in position in relation to one form of breaking and reaction wheels;
FIG. 5 is a section taken along the line 5-5 in FIG.
FIG. 6 is a section taken along the line 6-6 in FIG.
FIG. 7 is a section taken along the line 7-7 in FIG.
FIG. 8 is a section taken along the line 8-8 in FIG.
FIG. 9 is a side elevation showing the assembled alternative beveled wheel breaking means;
FIG. 10 is a section taken along the line I0-10 in FIG. 9; and
FIG. 11 is a section taken along the line llll in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT As appears in FIG. 1, 2 and 3, one specific embodiment of a mechanical mole utilizing my invention comprises a cutter head assembly including a series of concentric annular cutter heads 5, 6, 7. 8 and 9 which are supported by spaced arms 11 extending radially from a central drive shaft 12 which is suitably rotated by means not shown. The annular cutter heads are echeloned forwardly from the center as appears in FIGS. 1 and 3. Extending forwardly from each of the cutter heads through 9 are a plurality of individual cutters, generally indicated at 14. The type, size and number of cutters depend on several variables including the type and hardness of rock or other material to be excavated, the diameter of the tunnel and the distance of the cutters from the tunnel centerline. The cutters are operated by the rotation of the cutter head assembly and are positioned on the concentric annular cutter heads such that the width of the circular groove cut by each individual cutter exceeds the thickness of the cutter head.
The resulting space between the cutter heads and the undisturbed concentric bands of rock prevents loss of energy by friction between these in-place bands of rock and the cutter heads. Furthermore, these spaces permit outward movement of the rock when pressure is exerted by the described breaking means to break pieces of rock from the concentric bands which are cantilevered from the undisturbed mass of rock.
One breaking means shown in FIGS. 4-8 includes an assembly of rounded roller or breaking wheel 22 mounted upon a shaft 26 guided in opposite upright slotted supports 27 mounted within the concentric annular cutter heads. The upright supports 27 are slotted as at 28 to permit the breaking wheel to move radially with respect to the center of the cutter head. Shaft 26 is carried on lever 29 which may be pivoted to move the breaking wheel toward the outboard concentric band of undisturbed rock. Flat wheel 21 is mounted upon a shaft 31 carried at the forward end of lever 29. The opposite end 32 of lever 29 engages a rod 33 which extends from a piston (not shown) that is provided in hydraulic cylinder 34. Intermittent extention of piston rod 33 radially outwardly moves breaking wheel against the outboard cantilevered band of undisturbed rock with a substantial breaking force. As is shown in FIGS. 4-8, the reaction of the breaking force is transmitted to solid in-place rock by flat roller 21 (FIG. 8). The face of breaking wheel 22 (FIG. 7) is rounded to exert a concentrated breaking force while the face of the reaction wheel 21 is flat to distribute the reaction force over a broad area of solid rock.
The thickness of the cutter heads need be only sufficient to contain the breaking mechanisms. The controlling dimension is the travel of the piston in the hydraulic cylinder 34. This travel is a function of the size of the hydraulic cylinder, operating pressure of the hydraulic cylinder and the leverage required to produce sufficient force to break the particular rock in the concentric bands.
An alternative breaking mechanism is shown in FIGS. 9, l0 and 11. This alternative includes a beveled or coneshaped breaking wheel 41 which continuously breaks rock from the cantilevered concentric bands of rock as the mole advances. The beveled breaking wheel 41 mounts on a shaft 42 which is carried intermediate the ends of opposite lever arms 43 and is guided in opposite slots 44 provided in upright supports 46. A flat roller or wheel is rotatably mounted at each end of lever arms 43 on a shaft 48 to distribute the reaction force to the inboard in-place rock.
The thickness of the concentric bands of rock which are to be removed by breaking can vary with the strength of the rock being excavated and the natural jointing system. Also, the thickness of the outer bands of rock (or space between cutter heads) can be greater than those toward the center because rock should break easier when on a large radius curve than a small radius curve.
The cutter heads are echeloned apart a distance such that the reaction wheel has firm bearing on in-place rock and the breaking wheel exerts breaking force on a band of rock remote from where it is cantilevered from the in-place mass. The amount of cantilever and therefore the amount of echeloning between concentric bands is again a function of rock characteristics and can vary with rock type and design features of the mole.
As the rock is broken from the concentric bands it will rotate with the cutter head assembly and then fall to the floor of the tunnel behind it primarily at the sides of the tunnel during the upward and downward motion of the broken rock while rotating with the assembly. The advance of the cutter heads and the intermittent breaking of additional rock also will displace the broken rock to the rear where it falls between radial arms 11 to the floor of the tunnel. As the cutting head assembly is generally coneshaped, rock will be deposited over a length of the tunnel floor. In some instances it may be desireable to add guide vanes on the concentric cutter heads to provide a more positive means of displacing the broken rock to the rear. This provision requires a wider cut by the cutters and may not always be neces sary.
While the principal purpose of the invention is to provide a mechanical mole which will economically drive tunnels in hard rock, it also should reduce the cost of driving tunnels by mechanical moles in all types of in-place rock and other materials. Optimum economy is attained in a specific rock or other material by modification of the several variables available including type and number of cutters, thickness of cutter heads, spacing between the concentric cutter heads, length of cutter heads and amount of echeloning between cutter heads.
I claim:
1. A continuous mining machine for excavating an in-place mass of rock or other solid material comprising a plurality of concentric annular cutter heads spaced apart and echeloned in the direction of excavation; means for rotating said cutter heads;
at least one cutter mounted on each cutter head for cutting an annular groove in said mass as the cutter heads advance; and
breaking means for applying breaking force to undisturbed bands of material between said grooves cantilevered from said in-place mass, said breaking means being mounted behind said cutters and including a breaking wheel supported within the an nular cutter head and extendible radially from the annular cutter head to apply a breaking force to the adjacent band of undisturbed material, and reaction means operatively connected with the breaking wheel to distribute the breaking force reaction from the breaking wheel to the in-place mass.
2. A device as in claim 1, wherein said machine includes a drive shaft; said plurality of concentric annular cutter heads mounted on spaced arms extending from said drive shaft; means connected with the drive shaft for rotating the drive shaft; each of said annular cutter heads extending forwardly of the drive shaft a greater distance than the next adjacent inner cutter head.
3. A device as in claim 1 wherein each breaking wheel is pivotally mounted upon a lever, and said reaction means includes at least one reaction wheel carried by the lever to distribute the breaking wheel reaction to said breaking force to said in-place mass.
4. A device as in claim 3 wherein a hydraulic cylinder is operatively connected to the levers to intermittently pivot each lever to move an associated breaking wheel into engagement with said band and said reaction wheel into engagement with said in-place mass.
5. A device as in claim 3 wherein said breaking wheel is a beveled whee] continuously extending radially from said cutter head.
6. A method for excavating an in-place mass of rock or other material, using a machine including a plurality of concentric annular cutter heads each having a cutter mounted thereon and a breaking means carried by the cutter heads behind the cutters and a reaction means carried by the cutter heads in operative connection with the breaking means, comprising the steps of operating the machine to cut a plurality of concentric annular grooves in the mass of rock echeloned in the direction of excavation and spaced apart by bands of undisturbed material cantilevered from the in-place mass, engaging said bands of undisturbed material with the breaking means and applying a breaking force to the bands in a direction transverse to the direction of excavation, and simultaneously engaging the in-place mass with the reaction means and distributing the reaction to the breaking force to the in-place mass.
7. A machine implemented method for excavating an in-place mass of rock or other material comprising the steps of first cutting a plurality of concentric annular grooves in said mass, said annular grooves being echeloned in the direction of excavation, with adjacent grooves being spaced apart by bands of undisturbed material cantilevered from said in-place mass and a root end attached to the in-place mass; and
then applying a breaking force to each of said cantilevered bands of undisturbed material adjacent the free end thereof in a direction transverse to that of excavation and simultaneously distributing the reaction to said breaking force to an adjacent noncantilevered portion of said in-place mass at a location forward of the root end of each respective cantilevered band of undisturbed material, each said breaking force and the distributed reaction thereto being applied to opposite sides of a respective groove.
8. A method for excavating an in-place mass of rock or other material comprising the steps of first cutting a plurality of concentric annular grooves in said mass,
said annular grooves being echeloned in the direction of excavation, with adjacent grooves being spaced apart by bands of undisturbed material cantilevered from said in-place mass, and
then applying a breaking force to each of said cantilevered bands of undisturbed material in a direction transverse to that of excavation and simulta neously distributing the reaction to said breaking force to an adjacent non-cantilevered portion of said in-place mass, each said breaking force and the distributed reaction thereto being applied to opposite sides of a respective groove.

Claims (8)

1. A continuous mining machine for excavating an in-place mass of rock or other solid material comprising a plurality of concentric annular cutter heads spaced apart and echeloned in the direction of excavation; means for rotating said cutter heads; at least one cutter mounted on each cutter head for cutting an annular groove in said mass as the cutter heads advance; and breaking means for applying breaking force to undisturbed bands of material between said grooves cantilevered from said inplace mass, said breaking means being mounted behind said cutters and including a breaking wheel supported within the annular cutter head and extendible radially from the annular cutter head to apply a breaking force to the adjacent band of undisturbed material, and reaction means operatively connected with the breaking wheel to distribute the breaking force reaction from the breaking wheel to the in-place mass.
1. A continuous mining machine for excavating an in-place mass of rock or other solid material comprising a plurality of concentric annular cutter heads spaced apart and echeloned in the direction of excavation; means for rotating said cutter heads; at least one cutter mounted on each cutter head for cutting an annular groove in said mass as the cutter heads advance; and breaking means for applying breaking force to undisturbed bands of material between said grooves cantilevered from said in-place mass, said breaking means being mounted behind said cutters and including a breaking wheel supported within the annular cutter head and extendible radially from the annular cutter head to apply a breaking force to the adjacent band of undisturbed material, and reaction means operatively connected with the breaking wheel to distribute the breaking force reaction from the breaking wheel to the in-place mass.
2. A device as in claim 1, wherein said machine includes a drive shaft; said plurality of concentric annular cutter heads mounted on spaced arms extending from said drive shaft; means connected with the drive shaft for rotating the drive shaft; each of said annular cutter heads extending forwardly of the drive shaft a greater distance than the next adjacent inner cutter head.
3. A device as in claim 1 wherein each breaking wheel is pivotally mounted upon a lever, and said reaction means includes at least one reaction wheel carried by the lever to distribute the breaking wheel reaction to said breaking force to said in-place mass.
4. A device as in claim 3 wherein a hydraulic cylinder is operatively connected to the levers to intermittently pivot each lever to move an associated breaking wheel into engagement with said band and said reaction wheel into engagement with said in-place mass.
5. A device as in claim 3 wherein said breaking wheel is a beveled wheel continuously extending radially from said cutter head.
6. A method for excavating an in-place mass of rock or other material, using a machine including a plurality of concentric annular cutter heads each having a cutter mounted thereon and a breaking means carried by the cutter heads behind the cutters and a reaction means carried by the cutter heads in operative connection with the breaking means, comprising the steps of operating the machine to cut a plurality of concentric annular grooves in the mass of rock echeloned in the direction of excavation and spaced apart by bands of undisturbed material cantilevered from the in-place mass, engaging said bands of undisturbed materiAl with the breaking means and applying a breaking force to the bands in a direction transverse to the direction of excavation, and simultaneously engaging the in-place mass with the reaction means and distributing the reaction to the breaking force to the in-place mass.
7. A machine implemented method for excavating an in-place mass of rock or other material comprising the steps of first cutting a plurality of concentric annular grooves in said mass, said annular grooves being echeloned in the direction of excavation, with adjacent grooves being spaced apart by bands of undisturbed material cantilevered from said in-place mass and a root end attached to the in-place mass; and then applying a breaking force to each of said cantilevered bands of undisturbed material adjacent the free end thereof in a direction transverse to that of excavation and simultaneously distributing the reaction to said breaking force to an adjacent non-cantilevered portion of said in-place mass at a location forward of the root end of each respective cantilevered band of undisturbed material, each said breaking force and the distributed reaction thereto being applied to opposite sides of a respective groove.
US37038873 1973-06-15 1973-06-15 Apparatus and method for cutting and breaking rock Expired - Lifetime US3887236A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US37038873 US3887236A (en) 1973-06-15 1973-06-15 Apparatus and method for cutting and breaking rock

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US37038873 US3887236A (en) 1973-06-15 1973-06-15 Apparatus and method for cutting and breaking rock

Publications (1)

Publication Number Publication Date
US3887236A true US3887236A (en) 1975-06-03

Family

ID=23459428

Family Applications (1)

Application Number Title Priority Date Filing Date
US37038873 Expired - Lifetime US3887236A (en) 1973-06-15 1973-06-15 Apparatus and method for cutting and breaking rock

Country Status (1)

Country Link
US (1) US3887236A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2746169A1 (en) * 1977-10-14 1979-04-19 Gesteins & Tiefbau Gmbh CUTTING HEAD FOR SHAVING STONE, ESPECIALLY FOR DRIVING FORWARD IN MINING
US4682819A (en) * 1984-03-12 1987-07-28 Roger Masse Method and apparatus for drilling hard material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1488066A (en) * 1921-12-30 1924-03-25 Firm Of Maschb Ag H Flottman & Tunneling or mining machine
US1723330A (en) * 1928-06-18 1929-08-06 Andrew B Cross Well-boring drill bit
US3050292A (en) * 1960-04-11 1962-08-21 Goodman Mfg Co Core breaker roller for rotary mining head
US3288532A (en) * 1964-03-10 1966-11-29 Union Oil Co Continuous mining machine and method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1488066A (en) * 1921-12-30 1924-03-25 Firm Of Maschb Ag H Flottman & Tunneling or mining machine
US1723330A (en) * 1928-06-18 1929-08-06 Andrew B Cross Well-boring drill bit
US3050292A (en) * 1960-04-11 1962-08-21 Goodman Mfg Co Core breaker roller for rotary mining head
US3288532A (en) * 1964-03-10 1966-11-29 Union Oil Co Continuous mining machine and method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2746169A1 (en) * 1977-10-14 1979-04-19 Gesteins & Tiefbau Gmbh CUTTING HEAD FOR SHAVING STONE, ESPECIALLY FOR DRIVING FORWARD IN MINING
US4682819A (en) * 1984-03-12 1987-07-28 Roger Masse Method and apparatus for drilling hard material

Similar Documents

Publication Publication Date Title
US4406498A (en) Shield tunneling method and machine therefor
KR930006410B1 (en) Shielding tunnel excavator
US4189186A (en) Tunneling machine
US3325217A (en) Tunneling and excavation through rock by core forming and removal
US2998964A (en) Rotary tunneling device having radially adjustable cutters
US3917010A (en) Small diameter horizontal tunneling machine
US3916630A (en) Tunneling methods and apparatus
US4371210A (en) Freely rotatable pick bit holder on rotary driven member and method
US3887236A (en) Apparatus and method for cutting and breaking rock
US2550202A (en) Rock cutting apparatus
US3693734A (en) Boring auger for horizontal earth boring machine
US3420577A (en) Tunnelling machine having independently operable cutting head and circular saw
US3288532A (en) Continuous mining machine and method
JP2019127805A (en) Outbreak apparatus of shield machine
US5626399A (en) Apparatus for cutting and excavating solids
US2804754A (en) Apparatus for tunnelling
US3332721A (en) Device having adjustable knives for forming tunnels in soil
US4013319A (en) Tunneling machine with massive guide for impact tools
US3643998A (en) Tunneling machine for noncircular bores
CA1110283A (en) Method and apparatus for mining minerals, especially coal formations
US3722957A (en) Gage scraper
RU2236593C2 (en) Method for driving minitunnels and head section of complex of equipment for realization of said method
US3008698A (en) Rotary boring head having disk breaker means
CN113153332A (en) Cutter head capable of adjusting balance of hob
JP3085215B2 (en) Excavator

Legal Events

Date Code Title Description
AS Assignment

Owner name: BECHTEL GROUP, INC., 50 BEALE ST., SAN FRANCISCO,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BECHTEL INVESTMENTS, INC., A CORP. OF NV;REEL/FRAME:004951/0883

Effective date: 19880915

Owner name: BECHTEL GROUP, INC., 50 BEALE ST., SAN FRANCISCO,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BECHTEL INVESTMENTS, INC., A CORP. OF NV;REEL/FRAME:004951/0883

Effective date: 19880915