US1129351A

US1129351A - Dredging apparatus.

Info

Publication number: US1129351A
Application number: US63149211A
Authority: US
Inventors: Simon Lake
Original assignee: Individual
Current assignee: Individual
Priority date: 1911-06-05
Filing date: 1911-06-05
Publication date: 1915-02-23
Anticipated expiration: 1932-02-23

Description

S. LAKE.

DREDGING APPARATUS.

APPLICATION FILED JUNE 5, 1911 Patented Feb. 23, 1915.

6 SHEETSSHEET 1.

- ZZZ/mums S. LAKE.

DEEDGING APPARATUS.

APPLIOATION FILED JUNE 5, 1911.

6 SHBETSSHEET 2.

Svwemfov Witueooeo M977- 4, M/f

Patented Feb. 23, 1915.

S. LAKE.

DREDGING APPARATUS.

APPLICATION FILED JUNE 5, 1911.

' Patented Feb. 23, 1915.

6 SHEETS-SHEET 3.

S. LAKE.

DREDGING APPARATUS.

APPLICATION FILED JUNE 5, 1911.

- Patented Feb. 23, 1915.

6 SHEETS-SHEET 4.

Elmaonfoz S. LAKE.

DREDGING APPARATUS.

APPLICATION FILED JUNE 5, 1911.

hm fil Patented Feb. 23, 1915.

6 SHEETS-SHEET 6.

S. LAKE.

DREDGING APPARATUS.

Patented Feb 23,1915. 6 SHEETS'SHEET 6.

' SIMON LAN, 0E MILFORD, CONNECTICUT.

DBAEDGING APPARATUS.

Application filed June 5, 1911.

To all whom it may concern:

Be it known that I, SIMON LAKE, a citizen of the United States, residing at Milford, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Dredging Apparatus, of which the following is a specification.

This invention 'lirelates to improvements in suction dredging apparatus and particularly to certain improvements in the apparatus shown and described in Letters Patent No. 867,984, granted to me Oct. 15,1907.

The object of the invention is to provide a cheap, simple and economically operated suction dredging apparatus having especially in view the recovery of gold and gold bearing materials from the beds of rivers and other comparatively shallow bodies of water, and convey the worthless materials away from the territory being dredged.

A further object of'the invention is to provide an apparatus that is particularly adapted for the recovery and saving of the light weight or flaky particles of gold.

The invention consists in a support, preferably in the nature of a barge or similar float, having a well therein in which is supported a vertically movable chamber that provides a working compartment whereby the operators may work immediately adjacent to the surface being dredged and which also forms a support for the suction pump or pumps and the location of various parts of the apparatus employed for collecting and lifting the gold and gold bearing materials to a gold saving table that is located upon the support where the gold bearing materials are thoroughly disintegrated so that the very fine and light-weight particles of gold may be separated and saved from the worthless materials.

Specification of Letters Patent.

. empties.

v PatentedlFeb.23,1l9]l5.

Serial No. 631,492

separating chamber for collecting the heavier particles or nuggets of gold that cannot be lifted by the suction pump and delivered to the gold saving table, and in certain other peculiar features of construction, and in the combinations and arrangements of parts as will be fully describedin the following specification and then pointed out in the claims;

1n the accompanying drawings, illustrating the invention, in the several figures of which like parts are similarly designated, Figure 1 is a side elevation of the apparatus. Fig. 2 is a plan View of the same, parts being broken away. Fig. 3 is a vertical longitudinal section on a larger scale drawn through the forward end of the apparatus. Fig. 4 is a horizontal section drawn on a larger scale on the line 4.4 of Fig. 3. Fig

5 is a vertical longitudinal section drawn through the gold separating and collecting chamber interposed in the suction pipe lead ing to the suction pump and the suction pipes leading to and from said.chamber. Fig. 6 is an end View of the intake suction pipe. Fig. 7 is a plan view of a portion of the gold saving table. Fig. 8 is a longitudinal section drawn on the line 88 of Fig. 7. Fig. 9 is a similar view illustrating the troughs of the table adjusted to permit of the worthless materials being washed from said troughs. Fig. 10 is a vertical section drawn through the cradle into which the discharge. pipe from the suction pump Fig. 11 is a transverse section drawn through the grizzly, the gold saving table and the shaking screen. Fig. 12 is a vertical longitudinal section of the grizzly, the shaking screen and the gold saving table illustrating a different form of gold saving table. Fig. 13 is a horizontal section drawn on the line 1313 of Fig. 12. Fig. 14 is a side elevation of a portion of the grizzly, the shaking screen and the gold saving table, parts being broken away and others shown in section.

1 designates a support, preferably a barge or similar float, having a well 2 adjacent to one end in which is arranged a vertically 'movable chamber 3 of cylindrical shape in horizontal section. The chamber 3 serves the double purpose of providing a working 4 and a top 5 which is connected airand water-tight to the upper end of said wall 4, and within the chamber 3 is arranged an annular wall 7 that is spaced from said outer wall 4 so as to provide an annular water-ballast compartment 8 into which water is admitted when the chamber is to be submerged. The wall 7 is connected: at

its top to the underside of the top 5 and at its lower end said wall is bent or flared outwardly and has its extreme bottom edge bent ,to form )3, vertical flange which is connected to the lower end of the outer wall 4;. The outer wall 4: is provided with a number of openings 9 which are arranged adjacent to the lower end of the wall and open into said waterballast compartment whereby water may be admitted to said compartment from the surrounding body of water, and in order to permit the ready and complete filling of said compartment I arrange a vent pipe 10 in the upper end thereof which is extended through the wall 7 and thence up through the top 5 so that the air trapped in said compartment may escape into the atmosphere. A valve 11 is arranged in the ipe' p the longitudinal and transverse directions with respect to the support 1, are four uprights 16 which are secured at their lower ends to the chamber 3 in any suitable manner and at their upper ends said uprights are connected by a circular bar 18, of inverted T-shape in cross section, which forms a track or guide for the outer end of a horizontally movable beam 19 which is pivotally connected at its inner end to a centrally arranged bracket 20 that is supported by upwardly and inwardly extended bars 21 carried by the uprights 16. To the outer faces of the uprights 16 are secured rack I bars 22 that extend down along the sides of the chamber 3 and these rack bars are meshed by pinions 23 that are carried by shafts 24 journaled in brackets secured to the support 1 and the ends of the shafts are provided with intermeshing beveled gears 25 whereby all of the shafts are caused ,torevolve at the same time and at the same speed as the chamber 3 is raised and lowered thus causing the chamber to be held in a horizontal position. If desired one of the shafts 24 may be provided with a pinion 26 to be meshed by a drive gear 27 carried by the shaft of the motor 15 and the pinion 26 is connected by a suitable shifting lever 28 whereby it may be moved into and out of engagement with the gear 27.

The top 5 of the chamber'3 is formed with a hatch opening 29 which is surrounded by an upwardly extending airand water tig'ht casing 30 which extends to the top of the uprights 16 and to the-extreme upper end of the casing is secured a hatchcoaming that forms a seat for an inwardly opening counter-balanced door 31 that is hinged to one side of the casing 30. The hatch opening 29 is also controlled by an inwardly opening door 32 which is journaled to the underside of the top 5 of thechamber and adjacent to its pivotal end the door is provided with a lug to which is pivoted a link 33' which is connected to an arm carried by a'rock shaft 34 that is journaled in the sides of the casing 30 and to one end of the shaft is connected an arm 35 upon which is held a weight 36 which counter-balances the weight of the door whereby the door may be easily closed. The doors 31 and32 are provided with suitable look ing devices 31 for securing them in closed position and these locking devices are operable from either side of the doors to facilitate entrance to and exit from either the working compartment or the air lock. By arranging a door at each end of the casing 30 the operators are able to enter or leave the working compartment without danger of the water rising therein to any appreciable extent, it being understood that to enter the working compartment it is only necessary to close and lock the upper door 31 and then admit enough compressed air in the air-lock or casing to equal the pressure in the working compartment when the lower door may be opened. Upon leaving the working compartment the lower door is first closed to prevent the escape of the air in said compartment when the upper door is opened. Compressed air is supplied to the working compartment to exclude the'water therefrom and to supply the compartment with fresh air while the operators are working therein, through a valve controlled supply pipe 37, and to the air lock by avalve controlled pipe 38 both of which lead from a supply tank, which in the present construction is shown to be the tank 13 although a separate tank may be employed if desired.

The top of the chamber 3 is formed with a central opening 41 which is surrounded by a downwardly extending suction pipe 42 that is securely held at its upper end to the lower side of the top 5 of the chamberand at its lower end the pipe is provided with ma am an annular flange upon which is swiveled the inner end of a horizontally movable rectangular casing 43 through which the water and materials pass on their way to the pipe 42. T o the outer end of the casing 43 is connected a suction pipe 44 having a flexible section 45 to permit of a vertical adjustment of the mouth of the pipe'44 whereby said pipe may be raised and lowered so as to adjust its mouth directly over the surface being dredged. The outer end of the pipe 44 is connected by links '46 with arms 47 that extend from the outer ends of a shaft 48 journaled in the sides of the casing 43 and having on one end a worm wheel 49 that is meshed by a worm screw 50 carried at the lower end of a vertical shaft 51 .Which is journaled on the side of the casing 43 and which carries an operating handle at its upper end by which the shaft is revolved. It is obvious that by revolving the shaft in one or the other direction the outer end of the suction pipe 44 will be raised or lowered.

The casing 43 provides a gold separating and collecting chamber in which the heavier particles of gold or gold nuggets are separated and collected from the gold bearing materials passing through the casing as will be hereinafter fully described and I shall hereinafter refer to the casing 43 as a gold separating and collecting chamber. In the chamber 43 are arranged baffle plates 43 to obstruct the passage of the water and materials passing through said chamber thus allowing the heavier particles of gold to break away from the lighter materials or be separated from the sand and gravel and to drop down onto the bottom of the chamber out of the direct path of the current therein.

Upon the top 50f the chamber 3 is located a suction pump 52 to the intake of which is connected a pipe 53 whose lower end is connected to the top of the chamber 3 and which surrounds the opening 41 thereby forming a continuation of the pipe 42. To the outlet of the pump 52 is connected an elbow pipe section 54 to which is swiveled a pipe 55 upon which is slidably retained an extension pipe 56 whose upper end is provided with an elbow section 56 that is swiveled to an elbow section 57 which forms a discharge pipe and which extends through and is securely held to the bottom of a trough 58 which'is mounted upon the support 1 adjacent to the well 2. The trough 58 is constructed with an inclined bottom 59, vertical sides 60 and ends 61, and over the central portion of the trough is arranged a vaulted top 62 whose central depending section forms a ll-shape cutting edge which is arranged directly over the center of the discharge mouth of the pipe 57 so that as the water and materials are forced from the pipe they will be deflected upon both sides of the trough thus not only evenly distributing the sand, gravel and other materials n both ends of the trough but also scatterlng them in a thoroughly disintegrated condition. Arranged within the trough with its central portion below the discharge mouth of the pipe section 57 is a concave grate section or cradle 63 whose ends are extended upwardly to meet the outer depending ends of the top 62 thus preventing the larger particles of the materials that are deposited ilpon the cradle from entering the trough 58. The ends of the cradle and the ends of the top 62 are supported by angle bars 64 which are arranged transversely of the trough 58 and have their ends connected to the sides of said trough. The. front and rear sides of the trough 58 are extended upwardly to meet the front and rear edges of the top 62 and the rear side is cut out as at 65 to provide an outlet for the larger particles of the materials discharged upon the cradle 63. I

Extending from the sides of the opening 65 are the side beams 66 of an inclined grizzly 66 onto. which the materials are washed from the cradle 63 and which serves to carry off the worthless materials or tailings over the rear end. of the support 1. The lower. end of the grizzly empties into an inclined chute 67 that extends over the end 95 of the support 1. The bottom of the grizzly is constructed of longitudinal grate bars to permit the gold and smaller particles of gold bearing materials to fall through the grizzly during their passage therethrough. To the we side beams .66 are connected the sides of a trough 68 arranged below the grizzly. The trough 68 is formed with a solid bottom 68 as shown. In the trough is arranged a shaking screen 69 that is supported by 105 links 70 beneath a short partition 71 in the upper end of the trough. The rear side of the trough 58 is formed with an opening 58 that communicates with the partition 71 and which is controlled by a slide 72. The pur- 110 pose of the opening 58' is to permit the fine particles of gold and gold bearing materials that have collected on the top of the materials deposited in the trough 58 to be discharged onto the shaking screen. The parti- 115 tion 71 is preferably constructed of sheet metal and is bent transversely to form grooves 71' that serve as gold collecting riffles which are designed to catch the heavier particles of gold as they pass from the 12c trough 58 to the shaking screen 69.

Below the shaking screen 69 is arranged a gold saving table 77 that is especially designed for catching, separating and saving the very fine and flaky particles of gold 125 from the black sand and other worthless materials that pass through the shaking screen and drop down onto the table. The gold saving table 77 is constructed of a table. The troughs 78 are constructed from' brass tubing by preference, slotted lengthwiseand with one of the longitudinal edges of the slots bent outwardly to form an apron 79 that overlaps the opposite edge of the slot of the adjacent trough, and these opposite longitudinal edges are bent inwardly as at 79' to form ledges to prevent the mercury from beingSwashed out of the troughs when the troughs are tilted to dump the sand and.

other Worthless materials therefrom, as will be fully described later on. The ends of the troughs are closed by disks 80 provided with journals- 81 having bearings in the sides of the trough 68. The journals 81 carry short lever arms 82 whose free ends are connected to'a common operating bar 83 which is connected at one end to an operating lever 84 pivoted on the side of the trough 68 whereby all of the troughs 78 of the table 77 may be simultaneously tilted from the position shown in Fig. 8 to the position shown in Fig.- 9, to permit of the sand and such worthless materials being washed from the troughs by the water passing over the table.

As shown most clearly in Figs. 7, 8 and 9, the troughs 78 are arranged in a rearwardly inclined plane, and' as the apron 79 ofone trough overhangs the adjacent edge 79 of the next succeeding trough, there is thus provided a series of gold collecting pockets which overflow successively into one another throughout the entire length of the table, thus assuring the collection of all of the very fine particles of gold from the worthless materials.

In order to thoroughly agitate the water, sand and other materials in the troughs so that the gold may be separated therefrom and allowed to drop down into contact with the mercury, andalso to provide an arrangement for sweeping the sand and other Worthless materials from said troughs when the latter are tilted, I arrange an agitator in each trough which is constructed of a revolving shaft 85 from whichextend a series of blades or arms 86 tha-t are designed to revolve in the troughs 78 during the passage of the materials over the table. The ends of the shafts are journaled in the pintles 81 and at one end are provided with pinions 87 which are meshed by a train of idle pinions 87 journaled upon stub shafts extending from a bar 88 secured to the side of the trough (38 below the pinions 87, and one of the shafts 85 is provided with a sprocket wheel 89 over which operates a sprocket chain 90 that passes around a drive sprocket throughout the length of the table, so that by the time the materials reach the end of the table they will be so thoroughly agitated that the small and very light weight particles of gold will have been separated from the worthless materials and allowed to collect in the bottoms of the troughs.

One of the links 70 has its pivot extended through the side of the trough 68 and provided with a depending arm 70 that is held by a spring 7 O" in engagement with a cam 73 carried by one of the shafts 85 so that as the shaft is revolved the cam will rock the arm 70 and thus transmit a vibratory motion to the screen 69 which agitates the materials dropped thereon so that the small gold bearing particles and fine pieces of gold will drop through the screen onto the gold saving table 77.

94 designates a conveyer belt that operates in the grizzly for conveying the rocks and large pieces of worthless materials down through the grizzly into the chute 67 from whichthey escape over the rear end of the support 1. The conveyer belt operates over sprockets journaled in bearings supported by the sides of the grizzly and one of the sprocket shafts is driven by a motor 94' mounted upon the support 1. 96 designates a receptacle arranged at the foot of the trough 68 into which the materials dumped into said trough are deposited. One end of the receptacle is provided with a gate valve to facilitate the removal of the materials deposited therein.

In order to permit the outer end of the suction pipe 44: to be easily and automati-.

cally moved in lateral directions so as to dredge a comparatively large surface without necessitating a lateral adjustment of the support 1, and also to provide for the breaking up of the materials and the conveying of them into the sphere of the in- .fiuence of the orifice of the suction pipe 44,

I provide the following apparatus: On top of the separating and collecting chamber 43 is mounted an automatically operated reversing motor 97 having a belt pulley mounted on its shaft which is belted to a pulley 98 carried by a shaft 99 that is journaled in suitable bearings arranged at the outer end of the top of said separating and collecting chamber, and upon the shaft 99 is keyed a worm screw 100 whic h is en aged by a worm wheel 101 carried by a she 99' that is journaled transversely. of the shaft 99. The outer end of the, shaft 99' carriesaparallel arms 104 in the outer ends of which are journaled the ends of a shaft 105 upon which between the arms is mounted a combined digging and conveying wheel'105 ha ing a series of outwardly extendin blades 106 projecting from its peripheryw ich are designed to dig up and convey the loose materials back toward the end of the suction pipe 44:. The shaft 105 carries a worm wheel 107 at one end which is meshed by a drive screw 108 carried at the outer end of a horizontally arranged shaft 109 that is journaled 'in bearings extending from the separating and collecting chamber 43 and to the inner end of the shaft 109 is keyed a bevel pinion 110 which is meshed by a bevel.

pinion 111 carried atone. end of a transversely arranged shaft 112 journaled in bearings depending from the lower side of the chamber 43 and at the opposite end of the shaft 112 is keyed a bevel pinion 113 which is meshed by a similar pinion 111 carried at the lower end of an obliquely arranged shaft 115 whose opposite end carries a similar pinion 116 that is meshed by a drive pinion 11? carried by the shaft of the motor 97. Suitable casings are arranged over the shafts and gearing to protect them from the sand and mud stirred up by the action of the digging and conveying wheel operating on the surface being dredged.

To the outer end of the oscillating beam 19 is connected a guide bracket in which operates a vertically movable guide pole 118 to the lower end of which is connected a wedge-shape cutting chisel 119 to which is connected the lower end of a supporting cable 120 that extends up over a guide pulley 121 carried by and at the outer end of the beam 19 and which extends from a drum 122 carried by the shaft of an automatically operated reversible motor 123 (diagrammatically illustrated) which is mounted upon the inner end of the beam 19. When current issupplied to the motor the cutting chisel is alternately raised and dropped upon the surface being dredged which loosens the materials which are then taken up and conveyed to the suction pipe 44 by the conveyer wheel 105. The pintle 1% of man. s

of the chamber 3, As

supported b the upwardly extending bars 21 and its ower end is extended through the top 5 of the chamber 3 and through a L stufiing box surrounding the opening in said top through which the shaft passes, and is journaled in a bearing carried by the top of the separating and collecting chamber 13,

To" the lower end of the shaft is keyed a pinion 128 that is meshed by a drive gear 129 surrounding the suction pipe 42 and which-is securely held to the top of said chamber whereby as the chamber is oscillated the beam 19 will be correspondingly moved so as to cause the chisel to work directly in front of the wheel 105.

The pump 52 is operated by a motor 92 on one end of the shaftof which is keyed a the-beam 19 is provided with a car wheel bevel gear'131 which is meshed by a bevel pinion 132 carried by a short sleeve 133 which is journaled in a bearing 134C carried by the shaft of the motor 92 and slidably retained in the sleeve 133 and keyed thereto is a shaft 135 upon the outer end of which is held a bevel gear 136 which meshes a bevel pinion 137 carried by the shaft of the pump 52. The lower end of the shaft is held in a bearing 138 carried by the shaft of the pump. By thus gearing the pump to the motor it will be, readily understood that as the chamber is lowered the bearings 13% and 138 will revolve on their respective supports so as to always hold the gears in oper ative position.

In operation; Assuming that the support 1 has been moved and anchored over the spot at which the dredging is to be done, the vent valve 11 is opened to permit the escape of the air from the water ballastcompartment 8 and the inlet of water to said compartment through the openings 9 which permits the chamber 3 to submerge by its own weight and the weight of the water ballast let into the compartment 8 until the chamber settles to a position immediately adjacent to the water bed. The op erator or operators then enter the air lock 30, close and lock the door 31 and then admit sufiicient compressed air into said air lock to force the water from the working compartment of the chamber 3 so that the operators may enter said compartment. A current is then supplied to the motor 92 which sets the pump 52 in motion and t0 the motor 97 which supplies the power for oscillating the separating and collecting cham her and other parts carried thereby so that as the material is sucked up by the pump the suction pipe 414 will be moved laterally thus covering a space large enough for removes the material and works itself down toward bedrock During this operation the support is moved back and forth so as to permit the removal of enough material to form an excavation large enough for the chamber to enter after which it is only necesary to move the support forwardly against the bank formed by the excavation. As shown in Fig. 3, the digging and conveying wheel 105 then works against the base of the bank and conveys the material back toward the inlet end of the suction pipe 44 while the chisel digger breaksdown the upper part of the bank directly in front of the wheel 105 so that the loose material may be taken up by said wheel and conveyed to the suction pipe 44. As the water, gold and gold bearing materials emerge from the suction pipe 44 they are drawn through the gold separating and collecting chamber where the larger particles or nuggets are deposited while the finer particles of gold and gold bearing materials and water are drawn up into the pump 52 from which they are impelled through the pipe leading from the pump and are finally discharged from the pipe section 57 and forced against the underside of the top 62 of the trough 58 from which the water and materials drop into the cradle 63 through which some of the heavier particles of gold that have escaped-through the separating and collecting chamber will drop together with some of the finer particles of the materials while the larger pieces of the materials and some of the lighter pieces will be washed out through the opening 65 into the grizzly 66 from which the fine materials and sand will drop into the shaking screen 69 which. agitates and scatters the materials so that they may fall through the openings in the screen and drop on the gold saving table 77 where the very fine particles of gold are separated from the worthless materials. As the water and materials rush down over the table they strike. the baflie plates 93 which deflect them down into the troughs and set up currents as indicated by the dotted arrows in Fig. 8 which tend to thoroughly disintegrate the materials so that the very fine and light weight particles of gold may come into contact with the mercury-in the troughs with -which the gold amalgamates while the worthless materials will be washed over into the succeeding troughs where the same operation is repeated throughout the whole length of the table so that by the time the materials reach the end of the table all of the gold will have been separated therefrom and the worthless materials deposited in the receptacle 96 from which they may be ga'thcred and again run over the table if desired. Durin the passage of the materials over the ta le they are further agitated in the troughs 78 by the agitators 85 which also serve to sweep the sand and such worthless materials from the troughs when they are rocked to the position shown in Fig. 9, and it may be stated here, as the worthless materials collect in the troughs the latter are tilted to the position shown in Fig. 9 to permit the same being washed out by the water rushing over the table and by the arms of the agitators.

As the apparatus works its way down through the water bed and to bedrock, where the heavier particles or nuggets of gold exist in all gold bearing water beds, the heavier particles of gold will be arrested in their upward movement in the separating and collecting chamber 43. I have found from experiments that even when the suction pump is located near the inlet end of the suction pipe, which is the most effective location for the reason that the velocity at the intake of the pump is assisted by the outside body of water above the ump, the heavier particles or nuggets of go (i cannot be lifted above a certain height owing to the high specific gravity of the gold and in consequence the gold will rise only for a short distance in the pipe where it hangs and drops back to the surface. from which it is lifted the mo ment the slightest reduction is made-in the lifting force of the pump, therefore by intel-posing a chamber in the suction pipe near the inlet thereof I am enabled to recover the larger and heavier particles of gold that it has heretofore been im ossible to recover by means of a suction dredging apparatus. By arranging the baflie plates 43' in the chamber 43 the water and gold bearing materials are whirled around as indicated by the arrows in Fig. 5, which action arrests the passage of the heavier particles of gold passing through the chamber and allows them to drop down out of the direct path of the current and collect on the bottom of the said chamber while the lighter particles of gold and gold bearing materials are carried through the chamber and up through the suction pipe by the influence of the pump.

When all of the loose materials have been removed from the, bedrock and the crevices and pot-holes therein are exposed, the heavier pieces of gold deposited in the crevices and pot-holes may be recovered by suitable implements handled by the operators working in the working compartment of the chamber 3, and as the said compartment is only a short distance above the bedrock it will be readily appreciated that the operators are able to step down on the surface without inconvenience and thus enabled to gather all the heavier pieces of gold that have settled in the crevices and pot-holes of the bedrock. As the trough 58 fills with the materials that have fallen through the cradle 63 the opening 58 is uncovered so that the materials may be washed out onto the shaking screen.

iaaaati lin Figs. 12 and s i show a slightly different construction of the gold saving table in which the table is provided with Hungarian rifiies 177 with only one revoluble thereby be saved. In some instances 1 may find it desirable to increase the number of troughs which will then be arranged as shown in dotted lines in Fig. 12.

Instead of the chisel 119,. any other suitable mechanism for loosening the material may be used.

Current wires to supply energy to the motors may extend from a suitable dynamo arranged in the support 1 or from a local sta tion as circumstances permit.

From'the foregoing it will be seen that l provide an exceedingly simple and highly eflicient apparatus that is especially adapted for the recovery of both heavy and lightweight particles of gold from all gold hearing water beds and from gold bearing locallties where an artificial lake, can be constructed.

What it claim is 1. In a dredging apparatus, the combination with a float and a vertically movable submergible chamber arranged in said float and open at its bottom, of a suction apparatus having a pipe extending into and toward the bottom of said chamber,a casing forming the intake of the suction apparatus and having a swivel connection with the lower end of said pipe, means arranged within the casing and movable with it for separating and collecting the valuable material, means to move said casing horizontally, a movable intake pipe applied to said casing, and means arranged in advance of said intake pipe to loosen the material to be dredged.

2. In a dredging apparatus, the combination with a submergible chamber having a working compartment open at its lower end, a support therefor, and suitable suction apparatus extending down into said chamber, of a casing arranged at the bottom of the chamber and forming the intake for the suction apparatus and having a swivel connection with said suction apparatus, and means to move said casing horizontally beneath the chamber, said casing provided with a movable suction pipe and transversely arranged bafiie plates.

3. A gold dredging apparatus, comprising a support, a vertically movable submergible chamber having a working compartment carried by said support, said com partment being open at its'lower end, means to supply air under pressure to said com:

partment to exclude water therefrom, a suc tion pump having an intake pipe that. extendsthrough said working compartment, a

gold separating and collecting chamber interposed in said intake pipe, a gold-separating and saving apparatus carried by said support, and a delivery pipe extending from said pump to said gold separating and saving apparatus.

4:. A gold dredging apparatus, comprising a support, a vertically movable submergible chamber carried by said support and having a water ballast compartment and a working compartment both of which open into the surrounding body of water, a valve controlled vent leading into said water ballast compartment, means to supply air under pressure to said ballast compartment,

' for the purpose specified, means to supply air under pressure to said working compartment to exclude water therefrom, a suction pump carried by said chamber, an intake pipe extending from said pump, a gold separating and collecting chamber interposed in said intake pipe, a discharge pipe extending from said pump, and a gold collecting and saving table arranged on said support into which the discharge pipe empties.

5. A gold dredging apparatus, comprising a 'submergible chamber having a working compartment that is open at its lower end to the surrounding body of water, and a water ballast compartment that also communicates with the surrounding body of water, means to vent said water ballast compartment to permit ingress of water thereto, means to supply air'under pressure to said compartment to empty it, means to supply air under pressure to said working compartment to exclude water therefrom, a suction pump having an intake pipe extending .support for said chamber, a casing forming an air lock extending from said chamber and communicating with said working compartment, means to supply air under pressure to said worlnng compartment to exelude water therefrom, a suction pump cara discharge pipe extending from said sucried by said chamber, an intake pipe extendtion pump, and a gold separating and saving from said pump, a gold collecting and ing table carried by said support into which separating chamber swiveled to the, lower the discharge pipe empties.

5 end of said pipe, an adjustable inlet pipe In testimony whereof I have hereunto set 15 connected to said gold collecting and sepamy hand this 31st day of May, A. D. 1911.

rating chamber, a combined digging and SIMON LAKE. conveying Wheel supported by said gold col- Witnesses: lecting and separating chamber, means for M. D. BLQNDEL,

1O oscillating the latter chamber horizontally, C. E. ADAM.