JPS634130A - Drilling method and apparatus - Google Patents

Abstract

A method and apparatus (2) suitable for excavating a soil mass and like granular materials in which pressurized gas, preferably air, is provided in a reservoir and directed through appropriate valve (4) and duct means to a converging/diverging nozzle (50) positioned at the exit of the duct means. The nozzle includes a restricted throat section and a diverging transitional section which terminates in an outlet section. The ratio of the area of the outlet section to the area of the throat section is greater than 1.0 and preferably greater than 1.2 or more, while the ratio of reservoir pressure to ambient pressure is greater than about 1.9 and preferably greater than 3.7, whereby a gas stream having a calculated velocity greater than Mach 1, and preferably in excess of Mach 1.5 or more, is produced. The high velocity gas stream infiltrates the soil mass creating fissures and cavities, then stagnates within the cavities and violoently expands to fracture the mass.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates generally to excavating soil and other particulate materials with high velocity gas streams. In particular, the present invention relates to a method and apparatus that utilizes a flow of supersonic gas, preferably air, to excavate particulate material, such as soil around a buried object. The present invention enables underground utility piping, conduits, etc. to be removed where conventional mechanical and manual excavation techniques would damage buried pipes, wires or cables, and in some cases create an explosion hazard. Particularly suitable for close and contact drilling.

If excavation is required in the vicinity of gas pipes, television cables, telephone lines, etc., conventional mechanical equipment such as power shovels or backhoes may be replaced with manual tools such as flJ, T-picks, or shovels. It was necessary to do this. Manual excavation not only severely slows material removal, but also does not completely solve the problem of accidental impact and destruction of buried utility piping. Such disasters can potentially damage valuable property and create troubling public nuisances. Furthermore, in the case of natural gas piping,
There is always a fear of injury to workers from the explosion hazards created by using hand tools in and around cast iron pipes. In such an environment, the sparks generated by the steel drilling tool hitting the pipe or stone can cause a gas explosion if there is a gas leak. In an attempt to overcome the reduced drilling speed caused by hand tools, attempts have been made to minimize or completely eliminate manual labor using various mechanized drilling means, such as scrapers, power brushes, fluid jets, etc. Ta. However, these measures have had limited success in the workplace, and at best they have only superficially resolved the dilemma. During operation, the cleaning mechanism quickly became dull and wore out, requiring frequent maintenance and replacement. Soil usually sticks to the cleaning mechanism and reduces its effectiveness, the brushes become clogged, and the scraper becomes caked with dirt. Additionally, the cleaning device itself can damage the surface being cleaned, and the scraper or plow can scrape or destroy pipes and valves if the device's control mechanism is inadequate or improperly set up. . In the case of liquid jets, such as water, the drawbacks are obvious.

- Large amounts of water are generally required, which creates drainage problems at the work site. Furthermore, water splashes during the water supply, covering the entire surrounding equipment with a layer of mud. In cold weather operations, water must be treated with antifreeze or other fluids to eliminate icing problems.

The invention is suitable for use around utility piping, pipes, conduits, etc., or adjacent to or in contact with fragile objects or structures, such as building foundations, that may be damaged by mechanized excavation equipment. This solves many of the problems previously experienced when drilling.

The present invention employs a jet stream of gas, preferably air, at a supersonic flow rate to provide a fast, efficient and safe technique in the previously mentioned laborious task. A method and apparatus for excavating or enclosing fragile elements is directed. The invention is suitable for use in the form of a hand-held tool, mounted on the frame of an excavation machine, or used in conjunction with automated robotic excavation equipment. The present invention provides a supersonic jet of air so that when directed against a mass of earth or similar granular material it creates fissures or cavities.

An impulsive, high-velocity air stream is either momentarily trapped in the cavities created in the soil, or trapped in the cavities or crevices by retention, rapidly displacing the expanding high-pressure air. The large inertial flow generated by the release causes rapid destruction of the local area. The enclosed or trapped air must expand, and as it expands it causes the soil to collapse from its weakest point under tension.

The present invention provides an apparatus for safely excavating soil in close proximity to gas pipes, water pipes, discharge pipes, underground cables, telephone lines, etc., which is extremely flexible. The supersonic air flow provided by the present invention is highly effective against soil and completely harmless to buried objects, including extremely fragile items such as underground television or telephone cables.

The present invention is significantly more productive than manual methods and virtually eliminates accidental destruction when a supersonic jet is directed at buried objects. The present invention preferably uses 11/2 the speed of sound, although it depends on the operating pressure and nozzle diameter used.
provides three times or more supersonic air jets. The air jet impinges on the soil surface, penetrates and destroys the soil mass, and deflects impermeable surfaces such as plastic or iron pipes or electrical cables and conduits. Therefore, the present invention is useful in cleaning operations as well as excavation.

Furthermore, the present invention is easy to operate and safe to use.
Provides a digging or cleaning device that can operate with standard commercially available near compressors. The device according to the invention provides a high velocity gas flow capable of penetrating and disrupting a wide range of soil types, from extremely hard but brittle soils, such as dry sintered clay, to extremely sticky soils. The device according to the invention is effective at practical separations from the nozzle and thus produces a supersonic jet which makes it easy to operate when implemented in the form of a hand-held device.

When implemented in a hand-held device, the present invention incorporates a unique low torque activation valve mechanism that employs high pressure reservoir gas as a pilot to facilitate opening the valve to high pressure supply piping. The valve body and cover provide a sealed environment against dirt, mud and water or other adverse environments, thus making it suitable for the rigors experienced on the job site.

In another embodiment of the invention, a small amount of water or gaseous COZ can be introduced to trap and flush solid particles to provide a frictional cleaning effect for the high velocity jet. In this way, the benefits of a friction agent can be obtained without introducing hose friction or friction contamination problems.

The present invention also provides an apparatus capable of generating supersonic gas flows with various cross-sectional shapes depending on the nozzle shape used. For digging, circular or square nozzles are preferred, while thin knife-shaped rectangular nozzles are particularly suitable for cleaning operations, such as cleaning solid objects from conveyor belts for bulk materials.

[Disclosure of the invention]

, the method and apparatus according to the present invention are about 6.3-7 9/a
provides the foregoing advantages and desirable features by employing a pressurized gas reservoir, preferably air, maintained at 90-100 psig;
The flow rate of the gas is regulated through suitable valve means to the barrel of the device fitted with a convergent/divergent nozzle at the end of its bore. The nozzle may have a circular, square or rectangular cross section depending on the desired form of air injection. The convergent/divergent shape of the nozzle is important in generating a supersonic air jet based on well-known principles of fluidics. In this type of nozzle, the boundary conditions between supply pressure and atmospheric pressure create a closed sonic flow in the nozzle skirt and a supersonic flow in the bifurcation branch. The dispensing section is widened so that the air speeds smoothly without impact droplets to produce maximum velocity and number at the nozzle exit. Blocked flow conditions are a known phenomenon that occur when the fluid flow rate reaches a maximum value for a given area of the nozzle throat at given upstream conditions of temperature and pressure. Thus, the flow velocity at the outlet of a convergent/divergent nozzle can be predicted by closely controlling the pressure ratio of the air in the reservoir to atmospheric pressure as well as the area ratio of the throat and nozzle outlet ramparts.

According to the present invention, to excavate most soils, wet clays from dry loam to sand, gas flow velocities faster than the speed of sound are required, in particular velocities of at least about Matsuha 2.
This is preferred in order to provide a more efficient means of excavation. The nozzle that generates the exit velocity of Matsuha 2 is approximately 1:1.685
The area ratio of exit area to throat area and approximately 7.8:l
The pressure ratio of reservoir pressure to atmospheric pressure is adopted. Thus, at sufficient flow rates, for example 3.38 m" (125 cubic feet) per minute, 6.3 to 7.7 Kg
Matsuha 2 exit velocities can be achieved using conventional near compressors that can typically generate reservoir pressures of lcrI (90 to 110 psffl).

In an embodiment of a hand-held device according to the invention, a trigger valve, which is normally spring biased toward a closed or inoperative position, is configured to act on a force of pressurized reservoir air that normally holds the valve in the closed position. A provision is made to begin flowing high pressure reservoir air around the valve in order to The valve member includes a valve stem located in a bore in the housing positioned in sealing engagement with a valve seat at an inlet end that communicates the valve body, or head, with pressurized inlet air. The valve also includes a second end carrying a piston having a larger diameter than the valve head.

An air inlet branch hole is formed in the valve body of the handle member, a first end communicating with the pressurized air channel upstream of the valve head, and a second end communicating with the inside of the valve housing adjacent the piston. It communicates with space. A four-rotatable trigger shaft is located in the space between the first and second ends of the air inlet hole, the shaft having an aperture formed across its diameter to allow the trigger shaft to move to an activated or actuated position. When rotated, it communicates with the aforementioned air inlet hole. In the actuated position, pressurized air from the inlet is directed into the space adjacent to the larger diameter piston, causing the valve to instantly release, and pressurized air from the reservoir passes through the valve body and into the bore of the barrel. and then to the convergent/divergent nozzle. The trigger mechanism is spring biased to a closed position when the operator fully releases its grip. The trigger shaft is also provided with a bleed orifice which communicates with the piston side air inlet hole to allow the branch hole to bleed when the trigger mechanism returns to its closed position. Additionally, it is preferred that the excavation device be equipped with an air pressure gauge to ensure that proper operating air pressure is maintained. In addition, the drilling equipment is constructed of non-corrosive, non-ferrous materials and is rust-proof.
Preferably, it should not generate sparks, making it suitable for use in explosive environments. Additionally, the barrel can be provided with an elongated pick element that projects outwardly from the nozzle to allow the operator to remove troublesome chunks of material during excavation operations. Will the barrel of the device be made with a straight length of pipe, or with a curved exit section for hard-to-reach applications? It may also be fitted.

In addition to quickly and safely excavating around various utility pipes, the present invention is also useful for deep trench excavation, cleaning clogged silos and chutes, excavating sidewalks and roads, and foundations for foundation building. It is also used for digging, cleaning potholes before road repairs, and digging utility pole holes in difficult terrain.

In summary, according to the method according to the invention, a gas tank containing a compressed gas, preferably air, is charged with at least about 5
．． It is maintained at a pressure of 3 Kg/cra. The pressurized air is conditioned and guided through suitable duct or hole means to a convergent/divergent nozzle located at the discharge end of the duct or hole. A convergent/divergent nozzle includes a restrained throat portion and a bifurcated portion terminating in an exit portion. The ratio between the cross-sectional area of the outlet part and the cross-sectional area of the throat part of the nozzle is greater than 1.0, preferably greater than 1.2, -
The ratio of reservoir pressure to outlet pressure is greater than about 1.9, preferably greater than about 3.7, so that the air injection has a calculated isentropic velocity greater than 1°, preferably greater than 1.5°. have The supersonic air jet is directed at a soil mass, etc., where the air jet penetrates the soil mass, becomes trapped, and then expands to destroy the green material. Water or gaseous CO2 in the air stream in front of the nozzle
is introduced, producing frozen or solid CO2 particles that are trapped in the supersonic air jet as a result of the rapid temperature change as it passes through the nozzle.

Other objects and advantages of the present invention will become readily apparent from the following description in conjunction with the accompanying drawings.

[Detailed description of the invention]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in which like parts are designated by like reference numerals throughout the drawings, a hand-held actuator constructed in accordance with the present invention is generally designated by the reference numeral 2. Drilling device #2 is a water and gas pipe 220 shown in FIG. 8) or a television,
It is particularly suitable for excavating buried utility pipes, such as electrical, telephone cables 22', entirely by hand. Referring to FIGS. 1 and 8, apparatus 2 includes high pressure air hose 16.
The compressor 20 is operatively connected to the generated high pressure air reservoir. Near compressors are usually used in construction works and have at least 6.3 Kv at the outlet.
A conventional type capable of delivering 125 cubic feet of material per minute at a reservoir pressure of 90 psig is preferred. air hose 1
6 preferably has a minimum inner diameter of about 1 inch to provide the air volume required for the intended drilling purpose. The device 2 includes a conventional quick-disconnect coupling 18f threadably fitable to the handle member 10 in the elementary conduit 24 shown in FIGS. 2 and 3;
6. The device 2 further includes a control valve body 4 with a trigger mechanism 12 for controlling the flow of high pressure air. The device 2 also includes a convergent/divergent nozzle 50 fitted into the bore 7 of the barrel 6 at the outlet end 8.
including. Compressor 20, as described in detail below.
Generating a blocked sonic flow state at the nozzle throat and an ultrasonic air flow at a branch branch at the outlet of the nozzle 50 according to the ratio of the throat diameter to the throat outlet diameter of the nozzle 50 at a predetermined supply air pressure from the nozzle 50; Provides the energy necessary for excavation. Preferably, the device 2 includes a handle 14 that is easy for the operator to grasp, and a pressure gauge 21 attached to the rear surface of the valve body 4 so that the operating air pressure can be viewed.

A valve mechanism for regulating the flow of high pressure air through the hand-actuated excavation device 2 is shown in FIGS. 2, 3, and 4. conduit 2
4 has a hole 25 communicating with the air hose 16 and with the high pressure air in the reservoir generated by the compressor 20. The conduit 24 is fitted into the handle 10 and attached to the valve body 4 by screws, soldering, etc. to provide an airtight fit. The inner bore 5 of the valve body 4 extends generally in the shape of a letter from an inner end adjacent the conduit 24 to an outer end adjacent the barrel 6.

The bore 7 of the barrel 6 also communicates with the bore 5 of the valve body. Barrel 6
is firmly attached to the valve body 4 in a gas-tight manner by means of a sleeve fitting 82 which is fixed to the valve body 4 via a threaded portion 83. - A pair of O-ring seals 84 and 86 are provided around the sleeve fitting 82 and the barrel 6 to provide a mechanically strong airtight seal.

, high pressure inlet air in bore 25 is sealed from bore 7 in the barrel via a valve member 28 movably positioned within bore 5 in the valve body. Valve 28 includes a head portion 30 having a tapered edge that sealingly engages a stud 34 of sleeve 32 secured within venturi-type bore 5 . A cylindrical hole is formed therethrough in the sleeve 32, which hole is sealed when the valve 30 is in the closed position shown in FIG. The tapered edge of the valve head 30 sealingly engages the tapered valve wall 34 in its closed position to prevent pressurized air from entering the bore 7 of the barrel. A generally cylindrical piston 38 is attached to the valve stem 36 of the valve 28 at the end opposite the head 30. The piston 38 is slidably located within a chamber 80 formed in the upper portion of the valve body 4 and is connected to the nut and washer 4 .
0 to the valve stem 36. Preferably, the piston 38 also includes an annular cutout 44 formed on its underside for receiving a coil spring 42. A cylindrical valve guide 46 is fitted within the valve body 4 and receives the valve stem 36 therein in a gas-tight manner. An O-ring 48 is fitted within the valve guide 46 to prevent air leakage around the valve stem that slidably moves therein. Coil spring 42 compressively engages the top of valve guide 46 and the bottom of piston 38 within section 44 to bias valve 28 and attached head section 30 against sealing ring 34 of sleeve 32 to a closed position. do. Additionally, an O-ring 47 is provided around the piston 38 to minimize air leakage around it.

In the closed position shown in FIG.
It is held securely in place against the valve stud 34 by high pressure air pressure within. As an example, if the valve head 30 has an area of 6.45 square centimeters (1 square inch) and the inlet pressure in the bore 25 is 7 Kv/ci (100 psig), then the valve head 30 can be separated and the air 45 Kf (100 lbs.) to fit into hole 7 of barrel 6.
More force is required. In order to overcome the relatively large release force required to open valve 28, conduit 2
A control valve is provided which is actuated by pilot pressure supplied from the main air supply within 5. The flow rate of pilot air is controlled by moving the trigger mechanism 12. The trigger mechanism is configured to selectively supply or exhaust air depending on the position of the trigger 12. A small diameter air inlet hole 62 is formed in the valve body 4 and communicates with the hole 5 at one end and with a first end of a hole 64 formed in the cylindrical trigger shaft 26. It is like that.

When the trigger is in the inoperative position shown in FIG. 2, hole 64 is out of communication with hole 62 and therefore no pressurized pilot air is provided to open valve 28. In the actuated position shown in FIG. 3, trigger 12 and its body shaft 26 can be rotated counterclockwise into full alignment with holes 62 and 64 to allow pilot air to flow therethrough.

Valve body 4 also includes a bore 66 configured to communicate with the second end of trigger shaft bore 64 when trigger 12 is in its actuated position. The bore 66 communicates with a vertically extending bore 68 also formed in the valve body 4, and the chain bore 68 communicates laterally with a circumferentially extending groove 72 formed around the cylindrical outer wall of the sleeve 32. communicates with a hole 70 extending into the
The groove communicates with the hole 74. The hole 74 communicates with a hole 76 formed in the valve body 4, and the chain hole 76 communicates with a passage 78 near the top of the valve body 4. Passage 78 is connected to piston 38 of valve 28.
The upper chamber 80 communicates with the upper chamber 80 .

The surface area of the face of piston 38 exposed to chamber 80 is greater than that of valve head 30. Therefore, trigger 1
2 is in the operating position shown in FIG.
, 74, 76, 78 to the chamber 80. The chamber 80 is also housed in an airtight body with a threaded cap 45 fixed to the valve body 4 and an O-ring seal 49. The pressurized pilot air provided by actuation of trigger 12 immediately causes valve 28 to move downward due to the unbalanced force exerted on the valve. This movement is piston 3
This occurs because the surface area of the valve head 300 is larger than the surface area of the valve head 300. The downward movement of the valve 28 causes the valve head to release;
and allows the pressurized air from the compressor 20 in the holes 25 and 5 to enter the hole in the barrel 6 and then into the nozzle 50 and the outlet 8 of the drilling device 2.

As shown in Figure 2, when the trigger mechanism 12 becomes inactive,
The pressurized air within chamber 80 flows through the aforementioned holes 78, 76.
．． 74, 72, 70, 68, 66 and then holes 87, 88t formed in the trigger shaft 26
-, the trigger shaft 26 communicates with a hole 89 formed in the valve body 4. The pressurized air in the chamber 80 above the piston 38 thus causes the trigger mechanism to deactivate causing the valve head 30 to momentarily move upwardly and become firmly against the sealing surface 34 of the sleeve 32. When the flow of air inside the excavation device 2 is stopped, the air is instantly extracted to the atmosphere.

As shown in FIG. 4, the trigger mechanism 12 and the trigger shaft 26 are connected to a torsion spring 2 attached to the trigger shaft 26.
7 in the inactive position. hole 64
Pressurized air leakage from and 70 is minimized through a plurality of O-rings 33, 35 and 35', which fit into slots formed around the trigger shaft 26 to close the valve. It sealsly engages with a fastening hole 37 formed in the body 4. A pair of cover plates 29 and 29' are fixed to the valve body 4 by means of a threaded fixture 31. Said plates 29, 29' seal the sealing shaft 26 and the bore 64 of the valve mechanism from the surroundings.

The only access to the interior of the valve is through a small-diameter pilot exhaust port (not shown), which allows a certain amount of fluid to ooze from between the trigger shaft 26 and the inner surface of the anchoring hole 37 of the valve body 4. By releasing the air flowing outward, it prevents dirt from entering. A conventional pneumatic pressure gauge 21 is also fitted into the valve body 4, and the pressure gauge is operatively connected to a hole 23 on the rear surface of the valve body 4, and the chain hole 23 is connected to the inside of the valve body when the drilling device #2 is in use. to allow the operator to monitor the pipe pressure. If the pressure is a certain value, for example 6.3Kg/f
If the near compressor falls below 90 psi, the operator is alerted to corrective action to ensure proper operation of the near compressor.

The materials of construction of the valve body 4, internal valve element, trigger assembly, and barrel 6 are preferably non-corrosive materials such as, for example, barbed bronze, stainless steel, and high impact plastics. In situations where sparks create an explosion hazard around natural gas fumes, barrel 6 and tip 58 may be constructed of non-ferrous, non-sparking materials, such as bronze. The handles 10 and 14, which are gripping parts of the excavating device 2, may be made of hard rubber, plastic, hard wood, or the like.

Please refer to FIGS. 5 to 7. The outlet end 8 of the supersonic drilling device 2 can be provided with various shapes of equipment suitable for the particular task desired. 1 and 5 show the outlet end 8 fitted with a pick-like tip 58 which allows the operator to loosen unusually stubborn lumps of material with a sharp point. Barrel 6 may be straight or may include a full curved or angled portion 60 at outlet end 8 as shown in FIG. The curved portion 60 allows the excavation device to work better in tunneling operations or in hard-to-reach areas under pipes and conduits.

The convergent/divergent nozzle 50 is securely attached to the end of the barrel 6, for example by silver solder or fine screws, so that the inlet end 52 of the convergent portion of the nozzle merges smoothly with the bore 7 of the barrel. The converging portion gradually tapers to a throat portion 54, which has the smallest diameter within the nozzle.

The nozzle then gradually increases in diameter until it reaches the exit section 5.
Ends with 6. The nozzle 50 has a portion 51 of reduced outer diameter at its inner end 52 which is received in a sliding fit in the bore 7 of the barrel 6. As shown in FIG. 5, when a pick-shaped tip 58 is used, the nozzle 50 is formed with a second reduced outer diameter portion 53 around its outlet end 56 to allow the tip 58 to be attached thereto. There is. The attachment can be done by brazing, screw connections, etc.

In fluid engineering, convergent nozzles (heat splitting,
It is known that the ideal maximum gas flow rate in frictionless adiabatic or isentropic flow (or without removal) is Matsuha 1, which occurs at the smallest part of the nozzle, or throat. Matsuha number is 50 nozzles
is defined herein as the ratio of the air injection velocity at the exit of the air to the sound velocity at that point. It is also known that supersonic flow is obtained when the nozzle area downstream of the nozzle throat is intensified to form a convergent/divergent nozzle of the type employed herein.

Therefore, in the field of fluid mechanics, a steady flow of supersonic speeds can be created from a gas, e.g. It is known that it is possible to obtain However, the Matsuzha number achieved by air injection at the outlet of a convergent/divergent nozzle is subject to a number of variations, such as the supply pressure, pressure boundary conditions such as atmospheric pressure, and the ratio of the area of the nozzle outlet to the area of the nozzle throat. It is also known that money is influenced by certain factors.

When the supply pressure reaches a predetermined limit value, a closed sonic flow is obtained at the throat of the nozzle, as shown at 54 in the figure. The gas is expanded isentropically from the sonic state at the throat 54 to the nozzle branch 55 and enters the supersonic region at the nozzle branch, assuming pressure and temperature conditions are satisfied.

In order to reach the sonic speed limit, the ratio of the area of the outlet 56 to the area of the throat 540 must be greater than or equal to one. All known formulas and calculation methods enumerate certain nozzle ratios required to achieve a given Matsuha value at a given pressure and temperature ratio for an isentropic flow of dry air through the convergent/divergent section of the nozzle. I tried making a table.

As the ratio of reservoir pressure to local pressure increases and as the ratio of outlet area to throat area of the nozzle increases, higher Matsch numbers are achieved. Table I
illustrates the above principle for an isentropic flow of dry air.

Table 1 1.0 1.895 1.00 1.5 3.675 1.176 2.0 7.830 1.685 2.5 17.075 2.629 3.0 36.644 4.213 3.5 75.926 6.739 4.0 150.796 10.612 PO = Reservoir pressure P = Atmospheric pressure on the outlet side A = Nozzle outlet area A* = Nozzle throat area The present inventor has determined that It has been discovered that flowing air-like gas streams can create and penetrate tiny cracks and cavities in soil and other granular materials, providing an incredibly effective medium for the excavation of those materials. .

The inventors believe that the supersonic flow penetrates the soil structure until it becomes completely lodged within the local cavity and actually acts as a momentary reservoir of high-pressure, decelerated air. I'm assuming. The stagnant air must then expand, and as it expands it forces the soil to break in tension in its weakest direction. The point forming the localized reservoir of high pressure provides the energy source for the final rupture of the material under tension, causing a pneumatic explosion as the high pressure air is rapidly expanded and released into the atmosphere. It starts almost instantly. Thus, the present invention transfers the pressure energy generated by the near compressor 20 to the localized excavation location where destructive forces are utilized, and also transfers such pressure energy instantaneously through its large inertial flow. It will be appreciated that there is provided a method and apparatus for creating the aforementioned cavities that store and release.

To illustrate the foregoing principles, a complete nozzle 50 suitable for use in earth excavation according to the present invention is shown in detail in FIGS. 9 and 10. The nozzle 50- is circular in cross-section and includes an inlet 52 having a hole of the same diameter as the bore 7 of the barrel, which may be about 2.22 centas (0.875 inches) in this example. The nozzle shape converges to a throat portion 54 having a diameter rAJ of 0.250 inches, for example. The nozzle hole then gradually widens into the branched portion 55. As another example, rDJ has dimensions of 0,68 cm (0,68 cm).
269 inches), and the rEJ is 0.44 cm (0,
172 inches) Trap equal. The diameter of the outlet 56 of the illustrated nozzle is designated rBJ and is 0.72 centimeters (0.283 inches). The dimension "C", which is the distance between the throat 54 and the outlet 56, is in this case 1.08 centimeters (0,
0 ambient temperature 21.1°C (70'F)
), the ratio of reservoir pressure to ambient pressure (po/p
) is about 4.5, and the flow capacity is 0.068? / second (0,1
Calculations using a compressor 20 of (1,20 CFM free air) (1,20 CFM free air) indicate that the aforementioned nozzle 50 can generate a supersonic air jet at a velocity of approximately 1.64 cm. .

Once again, the calculations are based on the assumption that the flow is isentropic, ie, the flow occurs without friction and without the addition or removal of heat. The inventor's tests have shown that circular nozzles have advantages over other shapes with respect to friction effects related to separation versus flow attenuation. The inventor also believes that there is a critical pressure below which many soils cannot be excavated efficiently.This critical pressure is approximately 5,6 K9/era (80 psig). . As the reservoir pressure (Po) increases, the drilling ability improves amazingly, reaching 5.6 da/cyt (8
0psig) to 7Ky/CI? L (100 psig
) The ability to raise the mate has been increased by 25%.

If desired, the shape of the ultrasonic jet can be changed from the aforementioned circular shape to a square or rectangle.

Figures 11 and 12 illustrate a nozzle 94 capable of generating a rectangular supersonic air stream that has utility in cleaning flat surfaces, such as gobey belts carrying loose materials. Nozzle 94 includes a body 95 with tapered side plates 102 and 102' with tapered split plates 104'i interposed therebetween. Plate 102.
102' and 104 are cover plates 101 and 103
The cover plate is held in place by a fixture 106. As can be seen in FIG. 11, tapered plates 102 and 104 define a converging portion 98, a throat 96, and a dispensing portion terminating in an outlet 100 of the nozzle. Identical nozzle shapes are formed adjacently by tapered plates 102' and 104, causing a rectangular air jet to be emitted from the outlet 100'. When activated,
Parallel jets emerging from outlets 100 and 100' meet at a short distance from the nozzle, making it ideal for cleaning operations where soil or other sticky or stuck materials need to be removed from flat surfaces. Provides a thin knife-like shape suitable for The same exit area to throat area ratio applies to rectangular nozzle 94 as described above with respect to circular nozzle 50.

In a further embodiment of the invention, as shown in FIG. 6, a substance that solidifies when cooled, such as liquid water or gaseous carbon dioxide, enters the hole 7 in front of the nozzle 50'. It can be introduced via a feed passage 59, which is shown in dotted lines in the figure. The water spray or gaseous carbon dioxide flow from said passage 59 is trapped in the air stream and the convergent/divergent nozzle 50' due to the large temperature drop that naturally occurs as the air stream is forced through the nozzle. As it passes through, it solidifies almost instantaneously. The frozen granules, ie solid CO2 granules, are then ejected with a high velocity air jet to provide additional friction in excavation and cleaning operations. As used herein, the terms "digging" and "cleaning" may be used interchangeably with respect to the intended use environment of the invention.

Carbon dioxide is recognized as a unique additive since it does not pose any residuals or treatment problems once dissolved.

To further demonstrate the effectiveness of the present invention, tests were conducted in the field comparing a hand-held excavation device according to the present invention with conventional manual excavation using a pick and shovel. For comparison, three common types of boreholes were created: surface notches, vertical holes, and horizontal tunnels. The results show the percentage improvement in the amount of material excavated in the same amount of time for the device 2 of the present invention over conventional manual operation. The results are shown in Table H.

Table ■ Surface cut 260 inches Vertical hole 240% Tunnel 327% The test shown in Table I uses near compressor 20 at approximately 7 Ky/c.
rl (100 psig) and the calculated air injection rate of the Matsuha 2. Therefore, from the foregoing results, the advantages of the present invention over commonly used manual methods are self-evident.

Furthermore, it will be clear to those skilled in the art that the hand-held actuator 2 can be modified to be mounted on mechanized excavation equipment, such as a backhoe. The device according to the invention can also be incorporated into automated robotic excavation equipment, and the invention is particularly suitable in this respect. Of course, it may also be desirable or necessary to modify the valve mechanism from hand-actuated to pneumatic, hydraulic, or other actuation means.

Although specific embodiments of the invention have been described in detail, it will be apparent to those skilled in the art that various modifications and alternatives to the details will occur in light of the teachings of this disclosure. Is recognized. Accordingly, the specific arrangements disclosed are illustrative only and are not intended to limit the scope of the invention, which should be defined by the following claims and their full scope of equivalents.

[Brief explanation of drawings]

1 is a side view of a hand-held actuating device constructed in accordance with the present invention; FIG. 2 is an enlarged cross-sectional view of the handle and trigger valve assembly of the device shown in FIG. 1; and FIG. 3 is a view taken along the line of FIG. FIG. 4 is a partial cross-sectional view of the trigger assembly taken along #IV-IV of FIG. 2; FIG. Partially sectional side view of the convergent/divergent nozzle in place on the barrel in preparation for the
Figure 7 is a partial side view of a barrel with an angled discharge section similar to Figure 7. Figure 8 is a partial side view of a barrel with angled discharge section. FIG. 9 is a perspective view of a hand-held actuator according to the invention as used in the present invention; FIG. 10 is an end view of the nozzle shown in FIG. 9, FIG. 11 is a partial plan view of a rectangular nozzle that can be adopted in the present invention, and FIG. 12 is a partial cross-sectional view of the rectangular nozzle shown in FIG. 11. FIG. In the figure, 2...Drilling device 4...Valve body 6...Barrel 8-outlet end 10...Handle 12...
Trigger mechanism 2o... Compressor 25... Lead
Pipe 26...Trigger shaft 28...Valve
30... Valve head 34... Valve hardness 50.94... Nozzle (4 people outside) FIG, 8

Claims (1)

[Scope of Claims] [1] A method for excavating a mass of granular material, such as a clod of soil, comprising: providing a reservoir for gas at a pressure at least about 1.9 times the pressure of the surrounding area adjacent to the soil or mass of granular material; conveying gas through duct means from a reservoir to convergent/divergent type nozzle means, accelerating the gas flowing through it to produce a gas stream exiting the outlet of said nozzle at a calculated speed of not less than Matsuha 1; A method of excavating a mass of granular material, such as a soil mass, comprising the steps of: directing a flow into the soil or mass of granular material so that the gas flow penetrates and destroys the mass. (2) The method of claim 1, wherein the gas in the reservoir is at least about 3.0 mm below ambient pressure.
Drilling method provided with 675 times more pressure. (3) The method of claim 2, wherein the nozzle includes a throat and an outlet portion defining a cross-sectional area of the nozzle, the cross-sectional area of the outlet portion being less than the cross-sectional area of the throat. A method of drilling, wherein the calculated velocity of the gas flow exiting the nozzle is at least about 1,176 times greater than about 1.5. (4) The method of claim 1, wherein the gas in the reservoir is at least about 7.8 m below ambient pressure.
Drilling method provided with triple pressure. (5) The method of claim 4, wherein the nozzle includes a throat and an outlet portion defining a cross-sectional area of the nozzle, the cross-sectional area of the outlet portion being at least less than the cross-sectional area of the throat. A method of drilling where the calculated velocity of the gas flow exiting the nozzle is about 1.685 times greater than about Matsuha 2.0. (6) A method as claimed in claim 1, wherein the gas in the reservoir is at least about 36.6 mm below ambient pressure.
A drilling method provided with 644 times the pressure. (7) The method of claim 6, wherein the nozzle includes a throat and an outlet portion defining a cross-sectional area of the nozzle, the cross-sectional area of the outlet portion being at least less than the cross-sectional area of the throat. 4.213 times, and the calculated speed of the gas flow exiting the nozzle is about 3.0 or more. (8) The method of claim 1, wherein the gas in the reservoir is at least about 15% below ambient pressure.
Drilling method provided at 0.796 times the pressure. (9) The method of claim 8, wherein the nozzle includes a throat and an outlet portion defining a cross-sectional area of the nozzle, the cross-sectional area of the outlet portion being at least as large as the cross-sectional area of the throat. 10.612 times and the calculated velocity of the gas flow exiting the nozzle is about 4.0 or more. (10) In the method according to claim 1,
A drilling method in which the gas is air. (11) In the method according to claim 1,
Selecting a material from the group consisting of liquids and gases that solidifies on cooling, and introducing said material into the duct means before the nozzle means so that said material cools and solidifies as it passes through said nozzle means. . A method of excavating, comprising the step of solid particles trapped in a supersonic gas flow exiting said nozzle means in diffused form. (12) The method according to claim 11, wherein the gas is air and the introduced material is water. (13) The method according to claim 11, wherein the gas is air, the introduced material is carbon dioxide, and the surrounding pressure is atmospheric pressure. [14] In a method for excavating a lump of granular material such as a lump of soil, the pressure of the surrounding area adjacent to the lump of granular material such as a lump of soil is about 2 to 37
providing a reservoir for gas at double pressure, communicating gas from said reservoir via duct means to a convergent/divergent type nozzle means comprising a throat portion and an outlet portion, and accelerating the gas through said nozzle means; hand,
generating a gas flow exiting the nozzle at a calculated speed of between about 1 and about 3, directing the gas flow to the mass of granular material such as soil, directing the gas flow to the mass of granular material such as soil; creating fissures or cavities in the mass, causing the gas flow to stagnate within the fissures or cavities, and expanding the stagnant gas to ambient pressure such that the force generated by the expansion A method of excavating a mass of granular material, such as soil, including steps, wherein portions of the mass are destroyed. 15. The method of claim 14, wherein the cross-sectional area of the exit portion of the nozzle means is between about 1 and about 10.6 times the cross-sectional area of the throat portion. (16) The method according to claim 15, wherein the gas is air and the surrounding pressure is atmospheric pressure. (17) A method according to claim 14, by introducing a material selected from the group consisting of liquid water and gaseous carbon dioxide, as the material passes through the nozzle means. A method of drilling which cools and solidifies and exits the nozzle means as solid particles trapped in the gas stream. [18] In an apparatus suitable for excavating a lump of granular material such as a clod of earth, a duct means configured to communicate with a reservoir containing pressurized gas, and located within the duct means,
nozzle means having a throat portion and an outlet portion each defining a cross-sectional area, the ratio of the cross-sectional area of the outlet portion to the cross-sectional area of the throat portion being greater than or equal to 1.0;
Apparatus for excavating a mass of granular material, such as a clod of earth, wherein said pressurized gas from said reservoir is adapted to generate a gas flow with a calculated velocity of greater than or equal to Matsuha 1 when said pressurized gas passes through said nozzle means. 19. The apparatus of claim 18, wherein the reservoir contains the pressurized gas at a pressure of at least about 1.9 times the ambient pressure adjacent to the mass of particulate material, such as a clod of earth. A drilling device that is designed to (20) The apparatus according to claim 18, wherein the ratio of the cross-sectional area of the exit portion to the cross-sectional area of the throat of the nozzle is about 1.685 or more, and the reservoir is adjacent to a mass of granular material such as a clod of soil. at least about 7° below the ambient pressure
．． A drilling device adapted to contain said gas at 83 times the pressure and to generate a gas flow at a calculated speed of approximately Matsuha 2 or more. (21) An apparatus as claimed in claim 18, including passage means for introducing solidifiable material into duct means before said nozzle means, wherein said material solidifies and becomes trapped in said gas stream. The excavating device is adapted to pass through the nozzle. (22) An excavating device according to claim 18, including valve means associated with the duct means and adapted to adjust the flow rate of gas from the reservoir to the nozzle means. (23) The device according to claim 22, wherein the valve means has a through hole and is positioned to communicate with the duct means and the reservoir when operatively connected to the excavation device. the valve means further includes a valve member having a head portion and a piston portion interconnected by a mandrel, the head portion being adapted to press the bore of the valve when the valve means is in an inoperative position. The valve means is adapted to seal the pressurized gas, and the valve means further includes pilot hole means adapted to communicate between the pressurized gas and the piston portion of the valve member when the valve means is in the actuated position. so that said pressurized gas flows through said pilot hole means and acts on said piston portion to move said valve member;
and a drilling device for releasing said head portion to allow pressurized gas to flow through the hole in said valve body to the duct means. (24) The apparatus of claim 23, wherein the valve means includes a trigger means which, when in the actuated position, communicates with the pilot hole means to allow pressurized air to flow therethrough. A drilling device comprising a rotatable cylindrical portion having a pilot port adapted to be spaced apart from the valve head and to close the pilot hole means when in an inoperative position. (25) The apparatus of claim 24, wherein the cylindrical portion of the trigger means is also configured to allow pressurized air to escape from the pilot hole means to the atmosphere upon movement of the trigger means to an inactive position. The drilling device that forms the bleed port. (26) The excavating device according to claim 18, wherein the duct means and the nozzle means are made of a material that does not generate sparks.