US1325263A - Art oe placer-mining - Google Patents

Description

J. C. PATTERSON.

ART OF PLACER MINING. v

' APPLICATION FILED FEB- 251 19H. v 1,325,263, v Patented Dec. 16,1919.

3 SHEETS-SHEET I.

John Curtis Paifarsom lwwmon- J. C. PATTERSON.

ART OF PLACER MINING.

APPLICATION FILED FE8.26. 1911.

Patented Dec. 16, 1919.

3 SHEETS-SHEET 2.

Jbim Ourfis Paiiaraon;

1. C. PATTERSON.

ART OF PLACER MINING.

APPLICATION FILED FEB. 26. 1911.

1,325,263. Patented De.16,1919.

3 SHEETS-SHEET 3- FIG'LZIT UNITED STATES PATENT OFFICE.

JOHN CURTIS PATTERSON, 0F EHILADELPHIA, PENNSYLVANIA.

ART or PLACER-MINING,

. To all whom it may concern:

Be it known that I, JOHN CURTIS PATTER- SON, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in the Art of Placer-Mining, whereof the following is a specification, reference being had to the accompanying drawings.

In order that the nature of my invention may be more readily understood, I have thought it best to preface the description with a general statement in regard to the method usually employed heretofore for the same general purpose, taking as a typical instance both ofthe old art and of the employment of my invention, a case where the work is to be conducted upon the bed of a stream of running water, the illustrations shown in the drawings being mainly diagrammatical.

In Figure I, I have illustrated, conventionally, in transverse section, a bed of .a stream in connection with devices employed in the method heretofore practised.

Fig. II, is a plan view illustrative of said old devices and method, on a reduced scale.

Fig. III, is a planview of a stream illustrative of the devices and method employed in practising my invention.

Fig. IV, is a transverse section of'the stream illustrative of my method, the scale of this figure being enlarged and substantially similar to that of the scale of Fig. I.

Referring now to Figs. I, and II, 1, represents the rocky underlying surface of a stream bed, 2-, the gravel orother relatively non-coherent material constituting the removable bed of the stream, and carrying the metallic values which are to be separated from the gangue. The dotted lines at 8, indicate the normal water level of thestream.

Heretofore the method of conducting placer mining upon streams of this charac ter wasby the use of structures known as wing dams, of which a typical instance is illustrated in Figs. I, and II. A longitudinal dike of crib work, indicated comprehensively at 4, and built up ordinarily of timbers 5, and 6, placed in alternate pairs and ballasted by pieces of rock 7 was so constructed along the center of the stream bed, followingsubstantially the general course of the stream so as to divide the area as nearly as possible into two equal channels, the direction of flow being indicated by the arrows in Fig. II. At the up Specification of Letters Patent.

stream extremity, this central dike of crib 1 Patented Dec. 16, 1919. Application filed February 26, 1917. Serial No. 150,894.

part of the wing dam. In this manner the water was diverted from that portion of the channel which lay between the longitudinal dike and the adjacent bank at the side to which the wing dam 10, extended, the length of the denuded portion of the bed being of course determined by the longitudinal extent of the dike 4. As a result of this method of. procedure, the water of the stream, whose normal level is indicated in -Fig. I, by the dotted line 3, was crowded into the remaining channel shown at the left hand side of Fig. I, or the side nearest the observer in Fig. II, and by reason of the diminution of area of cross-section, rose to a level which may be taken as that indicated .at 11. The gravel, etc., of the stream bed at the dammed ofi side of the dike t, was then removed in any of the ways characteristic of placer mining, and after this the wing dam, represented at 10,'was torn down, or disconnected from its original location, and was rebuilt or reconnected to the opposite bank of the stream, so as to repeat upon the other side of the .dike 4, the procedure above described. As thus conductecl, the methodwas open to serious disadvantages among which may be noted the following:

Owing to the structure of the crib work employed, not only was a relatively large portion of the value-bearing bed directly covered by the dike itself, but, in order to insure stability of the dike, the excavation of the uncovered portions of the bed was greatly restricted. Thus, in Fig. II, I have indicated by the dotted lines 15, and 16, respectively, the angle of slope oneach side of the dike 4, which was characteristic of the necessary amount of residual material, said material being thus practically lost for the purposes of the mining operation. Speakstream.

cally only one such dike could be employed in any given portion of the stream, and consequently the water pressure due to the increased level was relatively high. I

By the method which I have invented,

these objections may be substantially ohviated and other advantages maybe derived, under similar condltlonsr 7 Referring now to Figs. III, and IV, 21,

represents the rocky bottom of the creek, 22,

other members adapted to serve as rails, are lttlCllongitudinally ,withthe stream to form a track. corresponding in length to the desired. length of thedam. Upon the tracks thus formed, a car or platform 30, provided with rollers31, is supported, said car carryingapile drivers, comprehensively indicated at1.34, and 35, respectively Since the details of such mechanism is well understood, it is not deemed necessary to give more than a conventional representation thereof.

The stream is then divided longitudinally into a plurality of channels, preferably three in number, as illustrated in Figs. III, and IV, by means of sheet-piling, formed of steel, extending down through the value bearing loose material, the sheets having interlocking edges which may be made substantially water-tight and being of such rigidity that their lower extremities can be driven firmly into the rocky bed 21, of the As these sheets are successively seatedv in place they may be stayed at the upper extremities by cross-braces 36, and 37 abutting. against the uprights 24, and 25. This adjunctive device, however, may not be necessary inv all cases. At the upstream extremity the central channel thus formed between the walls of sheet piling 38, and 39, is closedby a small crib work 40, (see Fig. III) having adouble inclined upper end, or by any other suitable deviceadapted to exclude water-from the central channel and divert it to the side channels.

Under these circumstances, the conditions illustrated in Figs. III, and IV, .will exist, the water level being raisedin the respec tive side channels to a degree illustrated at 41, and 42, .so that the external pressure against .thenlongitudinal walls is relatively much less than-that whichwas characteristic of the method-shown in Figs. 1, and II;

The value-bearing material in-the central channel is then excavated, the removal being complete. After this the crib or head of the wing dam 40, is removed. The water is then allowed to reenter the central channel, said wing dam being reconstructed at the up-stream end of one or theother of the side channels previously formed.

Under these circumstances, the water will be diverted from that side channel and the excavation of thebed thereof can proceed to the utmost extent required. Then this is completed the wing dam crib is removed to the upstream end of the remaining. channel and the water is diverted therefrom so that the bed of said channel can-be excavated.

The braces shown at 36, and 37, may be so constructed and attached as to constitute either compression members or extension members forthe support of the sheet-piling, but obviously if the pressure due tothe divergence of the water from either of. the side channels be so high as to endangerthe structure, props or other adjuncts may be employed to support the wall.

It will thus be seenthat by theemployment of my invention, the amount of valuebearing material which is directly covered by any portion of the structure is reduced .to a minimum, since even though a crib be employed for the transverse wing: dam memher, the cross-sectional area thereof is rela tively very small. It is obvious however, that even this covered area may be reduced by the employment of sheet-piling or :other devices to constitute the angularupstream extremity of the wing dam.

I am aware that the use of sheet piling with interlocking edges, is not new, and the reference thereto in the foregoing; specification is simply to indicate a preferred feature employed in carrying out the procedure characteristic of my invention.

Having thus described my invention, I claim:

1. The hereinbefore described improvement in the art of placer mining of a stream, which consists inseparating the water area of the stream and the value-bearing loose material, for an extended distance, intov a plurality of longitudinal ichannels, thinly divided from one another by means extending down through said loose material; successively closing the upstream extremities of the channels so formed while permitting the water to flow through anopen channel; and successively removing the value-bearing material from each closed channel.

2. The hereinbefore described improvement inthe art of placer mining of a stream, which consists in separating the water area of the stream and the value-bearing loose material, for an extended. distance, .into three ormore longitudinal channels, thinly divided from one-another by means extending through said loose material; proceeding, in permutation, to close the up-stream extremity of a channel, While permitting the Water to fioW through the others; and successively removing the value-bearing material from each closed channel.

In testimony whereof I have hereunto signed my name at Philadelphia, Pennsylvania, this twenty-first day of February, 191

JOHN CURTIS PATTERSON. Witnesses:

JAMES H. BELL, E. L. FULLERTON.

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