US3843198A

US3843198A - Rock sampling tool

Info

Publication number: US3843198A
Application number: US00344638A
Authority: US
Inventors: J Reynolds
Original assignee: Teck Metals Ltd
Current assignee: Teck Metals Ltd
Priority date: 1972-03-30
Filing date: 1973-03-26
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22
Also published as: GB1391373A; SE389535B; CA980144A

Abstract

In the sampling of a rock surface, dust that is formed by action of a compressed air driven rock cutting wheel is entrained in an air stream that is drawn into a shroud that surrounds all but a minor part of the cutting edge of the wheel and thence to a cyclone where it separates into a sample collector. High velocity exhaust air from the wheel-driving mechanism passes through an air ejector to provide a vacuum that causes the air stream to flow through the sample collecting system.

Description

United States Patent [191 Reynolds [45] Oct. 22, 1974 [54] ROCK SAMPLING TOOL [75] Inventor: John Windley Reynolds, Kimberley,

B. C., Canada [73] Assignee: Cominco, Ltd., Vancouver, British Columbia, Canada [22] Filed: Mar. 26, 1973 [21 Appl. No.: 344,638

[30] Foreign Application Priority Data Mar. 30, 1972 Canada 138576 [52] US. Cl 299/18, 73/425.2, 125/13, 173/30, 173/60, 175/58, 175/206, 299/64 [51] Int. Cl. E2lc 37/22 [58] Field of Search 125/13; 73/425, 425.2; 299/18, 64, 67, 89; 173/30, 60; 175/58, 60,

[56] References Cited UNITED STATES PATENTS 2,008,768 7/1935 Neal 173/60 X 7/1939 Muncy 175/60 X 10/1940 St. Clair 299/89 Primary Examiner-Ernest R. Purser ABSTRACT In the sampling of a rock surface, dust that is formed by action of a compressed air driven rock cutting wheel is entrained in an air stream that is drawn into a shroud that surrounds all but a minor part of the cutting edge of the wheel and thence to a cyclone where it separates into a sample collector. High velocity exhaust air from the wheel-driving mechanism passes through an air ejector to provide a vacuum that causes the air stream to flow through the sample collecting system.

7 Claims, 2 Drawing igures ROCK SAMPLING TOOL particularly directed to a rock sampling tool used pri-.

marily in geological exploration to take samples of exposed rock surfaces. It provides easy means of getting good samples of such rock surfaces or rock faces and can be sufficiently small and compact to be conveniently carried and operated by one man.

In the most commonly used method of rock face sampling, the geologist spreads a blanket below the surface to be sampled. He knocks chips off the surface with hammer and chisel and collects the chips on the blanket. It is also known to drill a number of holes into the face of the rock and to collect sludge that is so formed. With chip sampling of heterogeneous surfaces, the proportion of soft rock material collected tends to be too high, and thus the samples collected are not representative of the face sampled. With drill sampling, means must be provided for collecting the sludge in a manner that avoids mixing of successive samples. In addition, frequent washing of equipment is essential.

SUMMARY OF THE INVENTION I have found that the foregoing disadvantages of conventional rock sampling techniques and apparatus can be substantially overcome by the sampling tool of the present invention by which shallow grooves are cut in a rock face by a rotating rock cutting wheel and dust formed thereby is carried by an air stream into a shroud that encases all but a minor portion of the cutting edge of the wheel. The air and entrained dust then flow to a cyclone where the dust separates into a sample collector. The driving mechanism for the cutting wheel or saw is operated by compressed air, the high velocity discharge stream of which provides suction to pull air and entrained rock dust through the sampling system. Improved sampling of a rock face is easily obtained by making patterned, shallow saw cuts in the area to be sampled. Dust from the saw cuts is drawn into the cyclone and is separated into the sample collector. A short period of operation without cutting or with reverse flow of air discharged from the saw driving mechanism through the open cyclone between samples purges the collection system, thereby providing clean separation of successive samples. The sample collector is supported in the open position on a framework attached to the base of the cyclone. A rubber band conveniently seals a plastic sample bag to the cyclone. Such a collector is very easily changed between samples.

It is a principal object of the present invention to provide a rock sampling tool that is readily portable and operable by one man and which permits easy sampling of rock faces and the like rock surfaces.

It is another object of the present invention to provide a rock sampling tool which obtains representative samples of heterogeneous rock surfaces for direct deposit into sample bags with clean separation of successive samples.

BRIEF DESCRIPTION OF THE DRAWING A fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, in which:

FIG. 1 is an illustration of the sampling tool of the invention in its operative position; and

FIG. 2 is a schematic view of the sampling tool showing more clearly the relationship of component parts.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, sampling tool driving mechanism 10, shown as a angle drill, is operated by high pressure air that enters through hose 11 and is controlled by throttle 12 to rotate wheel 13 of a rock cutting saw. Shroud 14 encases the wheel except for a small segment of the cutting edge projecting from the shroud. Parallel edges 15 of shroud 14, disposed on either side of wheel 13, serve as a depth gauge for the saw cuts.

Exhaust air from drill 10 flows through hose 16 to inlet 17 of ejector 18 from which it is released through outlet 19. Rapid flow of this air stream through ejector 18, which operates as an aspirator, provides a low pressure zone or vacuum to draw air from the sampling system through a nozzle attached to opening 20. The sampling system comprises shroud 14 which substantially envelops wheel 13, shroud off-take hose 21, cyclone 22, sample collector 23 and cyclone off-take hose 24.

Rock dust that is formed during operation of cutting wheel 13 on a rock face is carried in an air stream passing into shroud 14 through hose 21 tangentially into cyclone 22 where it separates under centrifugal forces from the air and descends through the cyclone cone into collector 23. After separation of the dust, the air leaves cyclone 22 through a vortex outlet by way of hose 24 to opening 20 of ejector 18 where it joins the exhaust air from drill 10.

The casing of saw driving mechanism 10 serves as a handle for convenient use by operator 25. It is also convenient to suspend the ejector over the operators shoulder, as shown, so that the cyclone and collector are positioned in front of him. With flexible hose connections, the drill and saw can be rotated to cause edges 15 to move horizontally, vertically or diagonally over irregular rock faces. A unit with a small diameter wheel is capable of sampling quite irregular rock faces.

A rock sampling tool of the present invention was driven by a conventional air powered 90 angle drill that was 9 r inches long, weighed 2.2 pounds and rotated at 2,000 rpm with an air flow of 12 cfm at psi. The compressed air may be provided by a portable air bottle, a scuba type of which will operate the saw for about 8 minutes. Air entered the drill through a length of self-coiling plastic air supply hose and its flow was controlled manually by depressing a throttle-that was attached to the drill casing. Exhaust air from the drill passed through a inch ejector and was vented behind the operator. The nozzle of the ejector was adjusted to apply effective vacuum to the sampling system for ingress of air into the shroud for entrainment of the dust formed by the cutting wheel and for its effective separation from the air flowing through the cyclone. A 3 34 inch diameter by inch shroud encased a 3 inch diameter cutting wheel to leave a small segment of the wheel, about k inch along a diameter, protruding beyond the straight edges of the shroud to limit the depth of a saw cut. The rim of the wheel was set with diamonds in a sintered matrix. This sampler cut a per minute. Air drawn into the shroud carried dust from the cutting zone to the cyclone through hose that was attached to a tangentially mounted dust off-take on the shroud periphery. A 2 inch diameter cyclone was used. A thimble-shaped wire supporting frame, about 6 inches long and l inches in diameter was attached to the base of the cyclone. A plastic sample bag was sealed to the cyclone base with a rubber band. The sampling tool operated effectively on dry and on wet rock faces. A clean cyclone before each sample was taken was assured by removal of the sample bag and momentarily closing the ejector exit. Exhaust air from the drill then blew out the open cyclone. Analyses for lead, zinc and iron in rock face samples obtained with this tool compared favorably with those of samples obtained by the chipping method.

What we claim as new and desire to protect by letters patent of the United States is:

l. A rock sampling tool comprising, in combination, a compressed air operated driving mechanism, a rock cutting wheel operatively connected to said driving mechanism, a shroud substantially enveloping said rock cutting wheel excepting a segment of said cutting wheel projecting therefrom, a cyclone having a vortex outlet and a conical base with a dust sample collector removably attached to said conical base, an air ejector, connecting means to carry exhaust air from said driving mechanism to said air ejector for creating a low pressure zone therein, connecting means between the interior of the shroud and the cyclone and connecting means between the cyclone vortex and the air ejector low pressure zone whereby rock dust formed during operation of said cutting wheel is carried into said collector.

2. A rock sampling tool as claimed in claim 1, in which said air ejector is an aspirator whereby air exhausting from said compressed air operated driving mechanism creates a low pressure therein which induces an airflow from the shroud to the cyclone to the air ejector through the connecting means for collecting cut rock in the cyclone for discharge therefrom.

3. A rock sampling tool as claimed in claim 1, in which said air ejector is an aspirator whereby air exhausting from said compressed air operated driving mechanism creates a low pressure therein which induces an airflow from the shroud to the cyclone to the air ejector through the connecting means for collecting cut rock in the cyclone for discharge therefrom.

4. A rock sampling tool as claimed in claim 1, in which said driving mechanism is a angle drill.

5. A rock sampling tool as claimed in claim 4, in

which said air ejector is an aspirator whereby air exhausting from said compressed air operated driving mechanism creates a low pressure therein which induces an airflow from the shroud to the cyclone to the air ejector through the connecting means for collecting cut rock in the cyclone for discharge therefrom. 6. A method of sampling a rock face which comprises supplying air under pressure to a driving mechanism having a cutting wheel with an enveloping shroud operatively connected thereto, feeding exhaust air from said driving mechanism to an air ejector to create a low pressure zone therein, said shroud being connected to a cyclone having a vortex outlet and a dust collector attached to the base thereof and said vortex outlet being connected to said air ejector low pressure zone, thereby causing an air stream to flow from said shroud to the cyclone and thence to the low pressure zone of said air ejector whereby rock dust formed by operation of the cutting wheel is entrained by the flowing air and is carried through the shroud and thence to the cyclone where it is separated from the air and from which it is passed into said collector.

7. A rock sampling tool .comprising, in combination, a compressed air operated driving mechanism, a rock cutting wheel operatively connected to said driving mechanism, an air ejector operated by exhaust air from the driving mechanism to provide a low pressure zone therein, a shroud which substantially envelops said rock cutting wheel excepting a segment of said cutting wheel projecting therefrom, a shroud off-take hose, a cyclone, a sample collector sealed to the base of said cyclone, and a cyclone off-take hose, said shroud offtake hose being adapted to carry air and entrained dust from said shroud to said cyclone, and said cyclone offtake hose being adapted to carry air from the vortex outlet of the cyclone to the low pressure zone of said air ejector.

Claims

1. A rock sampling tool comprising, in combination, a compressed air operated driving mechanism, a rock cutting wheel operatively connected to said driving mechanism, a shroud substantially enveloping said rock cutting wheel excepting a segment of said cutting wheel projecting therefrom, a cyclone having a vortex outlet and a conical base with a dust sample collector removably attached to said conical base, an air ejector, connecting means to carry exhaust air from said driving mechanism to said air ejector for creating a low pressure zone therein, connecting means between the interior of the shroud and the cyclone and connecting means between the cyclone vortex and the air ejector low pressure zone whereby rock dust formed during operation of said cutting wheel is carried into said collector.

4. A rock sampling tool as claimed in claim 1, in which said driving mechanism is a 90* angle drill.

5. A rock sampling tool as claimed in claim 4, in which said air ejector is an aspirator whereby air exhausting from said compressed air operated driving mechanism creates a low pressure therein which induces an airflow from the shroud to the cyclone to the air ejector through the connecting means for collecting cut rock in the cyclone for discharge therefrom.

6. A method of sampling a rock face which comprises supplying air under pressure to a driving mechanism having a cutting wheel with an enveloping shroud operatively connected thereto, feeding exhaust air from said driving mechanism to an air ejector to create a low pressure zone therein, said shroud being connected to a cyclone having a vortex outlet and a dust collector attached to the base thereof and said vortex outlet being connected to said air ejector low pressure zone, thereby causing an air stream to flow from said shroud to the cyclone and thence to the low pressure zone of said air ejector whereby rock dust formed by operation of the cutting wheel is entrained by the flowing air and is carried through the shroud and thence to the cyclone where it is separated from the air and from which it is passed into said collector.

7. A rock sampling tool comprising, in combination, a compressed air operated driving mechanism, a rock cutting wheel operatively connected to said driving mechanism, an air ejector operated by exhaust air from the driving mechanism to provide a low pressure zone therein, a shroud which substantially envelops said rock cutting wheel excepting a segment of said cutting wheel projecting therefrom, a shroud off-take hose, a cyclone, a sample collector sealed to the base of said cyclone, and a cyclone off-take hose, saId shroud off-take hose being adapted to carry air and entrained dust from said shroud to said cyclone, and said cyclone off-take hose being adapted to carry air from the vortex outlet of the cyclone to the low pressure zone of said air ejector.