US2386295A - Clam dredge - Google Patents

Description

Oct. 9, 1945. J; w. DANIELS I 2,386,295

. CLAM DBEDGE Filed March 8, 1944 6 Sheets-Sheet l lllllll lllllll I urmtm' Oct. 9, 1945.

' Fil'ed March 8, 1944 J. W. DANIELS CLAM DREDGE 6 Sheets-Sheet 2 Inventor 5 I Attorm ys I Oct. 9, 1945.

J. w. DANIELS CLAM DREbGE 6 sheets-sheet 5 Filed March 8 1944 Oct. 9, 1945. J. w. DANIELS Q 2,386,295

CLAM DREDGE Filed March 8, 1944 6 sheets sheet 4 Inventor Oct. 9, 1945. J. w. DANIELS CLAM DREDGE.

Filed March 8, 1944 6 Sheets-Sheet 5 Invenior 'dislodgment ,of the I digging wheel preparatory to separating the dirt wherein a second Patented Oct. 9, 1945 UNITED STAT Es" PATENT oFFIcE .CLAMDREDGE James W. Daniels, FortMyers, Fla. Application Marc 8, 1944, SerialNo. 525,569 5 r 6 Claims, (CI. 37-55) a Q 7 This invention relates to improvements in clam dredges of that type embodying a barge or scow formed centrally with a longitudinal opening through which the. clam digging and elevating mechanisms are operated. The primary object of the present inventionis to provide a clam dredge of the above kind wherein a clam digging wheel is mounted in front of a main clam elevating conveyor .in spacedrelation to the latter, wherein a-Inechanically vi- ,rated breaker grate is arranged ata .r'earward inclination between the clam digging wheel and said conveyor to separate the dirt from the clams and deliver the latter from the wheel to the for-. ward receiving end of the conveyor, and wherein fluid jets are provided to loosen the dirt and clams from the digging wheel in advance of the breaker gate so that the latter may effectively complete dirt and. clams from said from the clams and delivering the latter to the conveyor.

A more specific object of thepresent invention is to provide a construction of the above char-ace ter wherein fluid jet nozzles are provided which are of a free flexible nature so that they may be located in close proximity to the periphery of the drum forming part of the digger wheel, and wherein the nozzles are carried by an oscillating manifold having yieldable means to resist turning thereof under the influence of the clams and dirt engaged in the teeth of the digger wheel, whereby said nozzles may follow the teeth of said wheel fromthe tips thereof to the periphery of the drum as the teeth pass said nozzles, thereby dispersing the dirt or mud and efiectively loosening the mud and clams from the wheel.

A further object of the present invention is to provide a clam dredge of the above kind wherein the main clam elevating conveyor is-pivotally 5 and slidably mounted at its rear discharge end,

within the opening of the barge or scow, and

auxiliary clam elevating conveyor is arranged'to receive the clams from the main conveyor and discharge them onto a sorting table provided on the deck of the barge or scow rearwardly of its opening, the auxiliary elevating conveyor being mounted on carriages forhorizontal movement so as to allow shifting of the main conveyor longitudinally of the barge while maintaining a fixed elevation of the discharge end of the auxiliary conveyor relative to the sorting table, 1 V j Another object of the present invention is to provide means for forwardly moving the dredge during the clam digging operation, whereby the dredgeiscaused to travel at-a uniformspee'dat all times, and meansfor driving the clam digging wheel, the speed of travel of the dredge being so timed with relationv to the speed of rotationof the clam digging wheel-that each row of teeth on'the clam digging-wheel is disposed to engage the river or like bed directly behind the shoulder left by the preceding row of teethsothat the digger wheel is not required to materially downwardly penetrate the riveror like bed after the start of each run or clam digging operation.

A further object of the present invention is.

to provide a novel and highly eificient form of digging wheelcomprising a drum having digging teeth secured in a novel manner thereto. I Other objects and features-of the present invention will become apparent from the following description when considered .in connection with the-accompanying drawings, andthe invention consists in the novel form, combination and. are rangement ofparts. hereinaftenmore fully described, shown in. the drawings and claimed. In the drawings, wherein like reference characters indicate corresponding parts throughout the several views: Figure .1 Lisa-top. plan view of a, clam dredge constructed in accordance withthe present invention.

Figure 2 is a fragmentary view thereof partly in side elevation and partly brokenawayandin longitudinal section;

Figure 3 is. anenlarged fragmentary vertical section takenonthe plane of line 33 of Figure .2, with parts omitted, forsake of clearness.

Figure 41s an enlarged fragmentary view partly in elevation and partly in longitudinal section, showing the..clam digging wheel and the adjacent end ,of the main clam elevating conveyor, together with associated parts.

Figure 5 is a fragmentary enlarge radial section through the diggerwheel, the plane. of section being indicatedby the .line 5--5 of Figure11.. U

Figure 6 is a fragmentary radial section taken on linefi.6 of Figure 5. we

Figure '7 is an enlarged fragmentary longitudinal section takenon line l -'l of Figure l.

Figure 8 is. a plan view of the construction shown in Figure 7. I g a a W Figure 9 isa transverse section taken on line 9,.9ofFigure8.' f 1 Figure 10 isan enlarged fragmentarylongitudinal section taken on line Ill-ll] of Figure 1.

Figure his a plan view showing anend portion the opening 6 and on opposite sides of the latter l are a pair of guide or track members I built in the form of closed loops and providing tracks for a pair of wheels 8, as shown more clearly in Figures 1, 2 and 7 to 9, inclusive." The wheels 8 are mounted upon a shaft 9 so that they may move longitudinally of the barge in unison upon the tracks 1, the upper members of the latter restraining the wheels 8 against becoming elevated from the lower members of the tracks. Mounted on the shaft 9 is a framework which includes a pair of stringers In that extend longitudinally of the opening 6. The forward end of this framework carries spaced uprights H that are rigid with the stringers l and embody upwardly converging members, to the forward ones of which are pivotally attached the ends of a bail l2. The bail 12 is engaged by a hook I3 on the end of a cable (4 of a hoist I supported at the top of a framework 16 erected on the deck of the barge 5 and straddling the opening 6 near the forward end of the latter. The framework embodying stringers I0 constitutes the frame of a main clam elevating conveyor that also includes an endless conveying element i1 consisting of spaced endless sprocket chains l8 passing around sprocket wheels on the head shaft 9 and on a foot shaft l9 journaled on the stringers l0 near their forward ends, said sprocket chains l8 being connected by a series of transverse pan-shaped flights 20 arranged in close relation, as shown in Figure 8.

As shown clearly in Figures 2 and 4, the stringers l0 project forwardly beyond the foot shaft l9, and mounted transversely across the forward ends of said stringers I0 is a transverse shaft 2| on which is rotatably mounted the drum 22 of a clam digging wheel. This drum is of hollow form and includes a cylindrical peripheral wall closed at its ends by means of end discs 23, one of which has a manhole 24 provided-with a cover 25 and suitably secured in place by bolting or the like, as at 26. Secured at regularspaced intervals to the inner surface of drum 22 so as to extend from end to end of the cylindrical wall thereof are channels 21 the outer edges of whose flanges contact the inner surface of the cylindrical wall of drum 22, as shown in Fi ure 5. The channels 21 have transverse longitudinal partitions 28 intermediate the inner walls of said channels and t e open outer edges thereof. The peripheral wall of drum 22 is provided with a longitudinal series of uniformly spaced slots 29 'which communicate with the channel and also register with slots 30 provided in the partition 28. 'The end walls of the slots 30 in partition 28 converge inwardly. and fitted snugly in each slot 29 and the slot 30 registered therewith is the .tapered shank of a digger tooth 3|. The inner ends of the shanks of teeth 3! are provided with transve se openings, and passing through these openings in each row of teeth is a securing rod 32 coacting with the adjacent partition 28 to tightly wedge the teeth in place. At corresponding ends, the rods 32 have heads disposed against the outer face of one end disc 23 of the drum 22, and removably engaged with the other ends of said rods 32 are securing caps 33. As shown in Figure 12, the securing caps 33 have spring-pressed detents 34 arranged to engage in bayonet grooves 35 provided in the adjacent ends of the rods 32 so as to releasably secure the caps on said rods and thereby retain the rods in place. It will thus be apparent that the drum 22 is provided with projecting peripheral teeth that are arranged in straight rows at regular intervals about the drum and extending from side to side of the drum. The construction is compact and durable and provides a simple and eflicient method of detachably assembling the teeth to the drum. As the teeth are of flat form and received in elongated slots of the drumand the partitions 28, said teeth are effectively positioned and held so as to curve at their outer ends in the same direction as that in which the digger wheel rotates while in operation.

Mounted transversely of the barge at the forward end of the opening 6 is a transverse shaft 36, and hinged at their forward ends upon the shaft are vertically swinging arms 31 whose rear ends are pivotally attached to the upper ends of the respective uprights ll. Thus, the digging drum is carried by the forward projecting portion of the frame of the main clam elevating conveyor, and by operating the hoist I5 the digger wheel and the forward end of the main conveyor may be raised or lowered, as desired. In doing so, the arms 31 cause the convey-or and digger wheel to shift longitudinally of the barge, which shiftin movement is permitted by travel of the wheels 8 in the tracks I. When the digging and conveying mechanisms are elevated to a substantially horizontal position within the opening 6, as indicated by full lines in Figure 2, the dredge is conditioned for travel from one point to another. However, the digger wheel may be lowered with the forward end of the main conveyor to any desired distance below the bottom of the barge for engagement with the river or other bed, depending upon the distance at which said bed is located below the barge.

As shown more clearly in Figure 4, the digger wheel is located so that it is spaced forwardly from the forward receiving end of the main conveyor, and so that it projects below this end of the conveyor when the digger wheel is in lowered operative position, as shown by dotted lines in Figure 2. It is accordingly necessary to provide means for delivering the clams from the digging wheel rearwardly and downwardly onto the receiving end of the main conveyor when the dredge is in operation. For this purpose, I provide a vibratory breaker grate 38 which is pivotally mounted upon the stringers l0 and occupies a rearwardly inclined position between the rear upper portion of the digger wheel and the forward receiving end of the main clam elevating conveyor, as shown in Figure 4. This breaker grate consists of a plurality of, spaced bars 39 centrally fixed to a transverse rock shaft 40 and disposed to pass between the digging teeth SI of the digger wheel. The arrangement is such that the upper ends of the bars 39 are normally spaced from the periphery of the drum 22, while their lower ends are arranged in the path of the back flanges of the conveyor flights 20. Thus, as each flight passes the lower ends of the bars 39, the

breaker grate is swung so that its upper portion is moved toward the periphery of drum 22, after which said breaker grate gravitates back to its normal position with the upper ends of the bars 39 spaced from the drum, as shown. Loose mud and dirt may pass between the bars 39 so as to fall on the river or like bed through the space between the digger wheel and the forward end of the conveyor, while the clams will be held on said breaker grate and will fall downwardly on the same for delivery to the conveyor.

Means is provided for discharging a plurality of powerful jets of fluid onto the periphery of the drum at the rear upper portion of the latter and at a point immediately before the rows of teeth pass to and between the bars of the breaker grate 38. As shown, this means includes a manifold 4| suitably mounted for oscillation about its longitudinal axis and extending transversely across the upper portion of the digger wheel near the rear of the latter. Manifold 4| is provided at regular intervals with depending flexible nozzles 42 that are directed at a downward and rear angle, as shown in Figure 4 and normally project in the path of mud between the digger'teeth 3|. Also, yieldable means 43 is provided to rock the manifold M to a'normal position wherein the nozzles 42 depend substantially vertically. Thus, as the digger wheel rotates, the mud between the rows of teeth will engage the nozzles 42 and flex them rearw-ardly, at the same time causing the manifold 40 to rock against the action of yieldable means or spring 43. In this way, the dis charge ends of the nozzles 42 are caused to follow the surface of the mud or dirt between the digger teeth and ultimatel discharge onto the surface of drum 22 at the points where the teeth project through the latter; Thus, the mud is effectively dispersed and loosened from the periphery of the drum 22 and from between the digger teeth so that little further effort will be required by the breaker grate to complete dislodgment of the mud and clams from the digger wheel. Most of the mud and dirt will be washed from the periphery of the drum-22 so as to pass therefrom onto the river bed between the digger wheel and the main conveyor. Remainingmud and dirt will be so discharged between the bars of the breaker grate so that substantially clean clams are all that are delivered to the elevating. conveyor. Water under pressure is delivered to the manifold 4| by a supply pipe 44 that is suitably extensible and coupled to the outlet of a pump 45 driven through chain gearing 46 by a motor 4'! mounted on the deck of the barge in front of the opening 6. The motor-41 is also connected to shaft 36 which chain gearing 48 to shaft 52, the latter shaft being connected bygearing 49 to drum 22 for driving the latter in a clockwise direction,-as viewed in Figures 2 and 4. The gearing 49 includes a sprocket wheel 50 bolted at to an end disc 23 of the drum 22. The gearings 48 and 49 include a sprocket wheel carrying shaft 52 journaled in the upper ends of the uprights H and on which the rear ends of the arms 31 pivot. This is clearly shown in Figure 2, and it will also be seen that gearings 53 and 54 operatively connect the shaft 52 with the head shaft IQ of the main clam elevating conveyor. Thus, motor 4! drives the digging wheel, the pump Y45 and the main elevating conveyor.

Disposed in a forwardly inclined positionrearwardly of the main conveyor is an auxiliarylconveyor 55 that is mounted upon' carriages 56-movoperatively is connected by I able longitudinally upon the deck of the barge rearwardly of the opening B'and mounted upon thehead shaft 9 of the main-conveyor. Conveyor includes an endless conveyor element having scoop or bucket-like flights 51 and driven by a sprocket gearing 58 between the head shaft 9 of the forwardmain conveyor and the forward foot shaft of said conveyor 55. A suitable chute 58 leads the clams from the upperdischargeend of the main-conveyor downwardly and-rearward- 1y onto the forward receiving end of the auxiliary conveyor 55. A sorting table 59 is disposed on the deck of the barge rearwardly of the opening 6, and a further chute 60 is carried by the discharge end of conveyor 55 so as to direct the clams from the latter rearwardly and downward- 1y onto the table 59. Chute 58 is slid-able onthe table 59 so that it will always remain thereon regardless of the forward or rearward shifting movements of the conveyor 55 with the main conveyor. Thus, the auxiliary conveyor will be maintained with its discharge end at a fixed elevation with respect'to the table 59 for continuously discharging the clams onto the latter. The carriages 56 permit the conveyor 55 to move forwardly orrearwardly with the forward main conveyor of the apparatus. In this way, it is possible to mount the discharge end of the main conveyor within the opening 6 or below the deck of the barge in a most desirable manner.

Means, driven by the motor 41, is provided for propelling the barge forwardly during th clam digging operation, and such means includes an anchor chain 6| extending from its anchor rearwardly through guides 62 and 63 on the deok'of the barge 5 at the bow of the latter. The anchor chain 6| passes over and meshes with a sprocket wheel provided at 64 upon a transverse shaft65 mounted .on the deck of the barge forwardly of motor 41. The-barge is provided with a well 56 directly at the rear of the sprocket wheel-64 into which the chain 6| may pass from said sprocket wheel 64 as the barge moves forwardly. The shaft 65 is driven by a chain gearing 61 from the shaft of motor 41. Thus, when the anchor of the chain 6| is placed on the bed of the river a distance ahead of the barge, and sprocket 64 is driven by the motor 41, the chain 6| is positively pulled so as to effect the forward travel of the barge. Due to the fact that the chain 6| does not wind on the shaft 55 and merely passes overa sprocket wheel 64 of constant diameter, the forward travel of the barge will be at a uniform speed. This speed is so determined relative to the speed of rotation of the digging wheel thateach row of teeth of said digging wheel will be disposed to engage the bed of the river directly behind the shoulder that was left by the preceding row of teeth, as indicated at 68 in Figure 2. Thus, the digging wheel is not required to materially dig downwardly into the river bed at any time during the clam digging operation, except at the beginning of each run. In this way, considerable saving of power and elimination of strain on parts and mechanism is accomplished. The dredge may be moved from place to place when not in operation by suitable propulsion means or by towing.

In operation, the chain 6| is paid out after its anchor is dropped on the bed of the river or the like, and the dredge is towed rearwardly to the desired point where it is intended to start the run of the clam digging operation. The hoist I 5 is then operated to lower the digger wheel onto the bed of the river, as indicated by dotted lines in Figure 2,'whereupon the motor [4 is'placed in operation. Motor thereupon drives the digger wheel and the conveyors and simultaneously effects forward travel of the barge by the action of sprocket" wheel 64 on anchor chain 8|. As the digger wheel rotates, the rows of teeth successively dig up the clams and mud and carry them upwardly and rearwardly until the jets of water from the nozzles 42 loosen and remove the clams and dirt to a great extent. Final removal of the clams and dirt is effected by the breaker grate 38, loose dirt falling onto the river bed between the digger wheel and the forward conveyor, and the clams passing onto the forward conveyor from the digger wheel downwardly along the breaker grate 38. The conveyor 55 receives the clams from the forward conveyor and, together with the chute 6D, ultimately delivers the clams onto the sorting table 59.

'It is pointed out that fixed jets of water directed onto the drum of the digger wheel have not been found entirely satisfactory, and by employing the flexible nozzles 42 and the rocking manifold therefor, the nozzles are allowed to follow the dirt and clams from the points of the digger teeth to-th'e periphery of the drum of the digger wheel, thereby completely and effectively loosening the dirt and clams and dispersing the dirt from the digger wheel. While some of the loosened dirt may slightly adhere to the drum 22 and to the clams, final separation of the dirt from the clams is effected by the vibratory breaker grate 38. It is further noted that when the digger wheel and forward elevator are swung downwardly, the arms 3Tcause them to also shift rearwardly as permitted by the movement of wheels 8 in tracks 1 and movement of carriages 56 on the deck of the barge. When lowered, in this way, the weight of the parts may be partially supported by reason of the semi-buoyant nature of the drum 22. At this time, the auxiliary conveyor conveyor 55 is shifted rearwardly so that the chute 60 is disposed to deliver onto the table 59. V

From the foregoing descrhiption, it is believed that the construction and operation, as well as the advantages of the present invention, will be readily understood and appreciated by those skilled in the art. It will of course be understood that the invention is susceptible to modification and various changes in details of construction illustrated anddescri-bed, such as fairly fall within the scope of the appended claims.

What I claim is:

1. In a clam dredge, a scow provided with a longitudinal opening, vertically adjustable, clam digging and elevating mechanisms operable through said opening, said elevating mechanism including an endless conveyor, and said digging mechanism includinga rotary digging wheel arranged in front of and spaced from the forward end of said conveyor, said conveyor having an endless conveying element provided with transverse pan-shaped flights, and a vibratory breaker grate centrally pivoted for oscillation about a horizontal axis and inclined rearwardly and downwardly from the from th rear upper portion of the digger wheel to the forward end of the conveyor, said diggerwheel having spaced transverse rows of spaced digger teeth, and said breaker grate including spaced rods arranged to have their upper ends pass between the digger teeth, said breaker grate normally gravitating to a position with its upper end spaced from the digger wheel and its lower end in the path of the flights of the. conveyorso that said flights will intermittently rock the breaker grate in a direction to move the upper end of the latter toward the digger wheel.

2. In a clam dredge, a scow provided with a longitudinal opening, vertically adjustable clam digging and elevating mechanisms operable through said opening, the digging mechanism including a digger wheel embodying a rotatable drum provided with uniformly spacedperipheral rows of spaced teeth extending'transversely of the drum, and fluid jet means for loosening the mud and clams from'the drum and its teeth at the rear upper portion of the digger-wheel, said last-named means including a manifold extending transversely of and above the rear upper portion of the digger wheel and provided with depending rearwardly inclined flexible jet nozzles depending to pass between the teeth of the digger wheel.

3. In a clam dredge, a scow provided with a longitudinal pening, vertically adjustable clam digging and elevating mechanisms operable through said opening,the digging mechanism including a digger wheel embodying a rotatable drum provided with uniformly'spaced peripheral rows of spaced'teeth extending'transversely' of the drum, and fluid jet means for loosening the mud and clams from the drum andits teeth at the rear upper portion of the digger wheel, said last-named means including a manifold extending transversely of and above the rear upper portion of the digger wheel and provided with depending rearwardly inclined flexible jet nozzles depending to passbetween the teeth of the digger wheel, said manifold being mounted for oscillation about its longitudinal axis, and yieldable means resisting turning of the manifold in a direction opposite to the rotation of the digger wheel, whereby the jet nozzles may be caused to swing rearwardly by mud and clams carried around by the teeth of the digger wheel.

4. In a clam dredge, a scow provided with a longitudinal opening, clam digging and elevating mechanisms'operable through saidopenin'g, said elevating mechanism including an endless conveyor having spaced transverse flights, and said digging mechanism including a rotary digging wheel arranged in spaced relation to and forwardly of said conveyor and having uniformly spaced peripheral transverse rows of digging teeth, the teeth of each row being uniformly spaced, fluid jet means for loosening mud'and claims from the teeth and periphery of the digger wheel at the rear upper portion of the latter, and mechanical means to complete removal of the mud and clams from the digger wheel after being subjected to the action of said jet means, said mechanical means including a rocking-breaker grate arranged at a rearward and downward inclination between the rear upper portion of the digger wheel and the forward end of the conveyor and pivotally mounted'intermediate its upper "and lower ends upon a; horizontal transverse axis, said breaker grate including spaced bars having their upper ends arranged to pass between the teeth of the digger wheel and their lower ends arranged in the path of the conveyor flights so that the latter vibrate the breaker grate about its pivotal axis when the dredge is in operation.

5. In a clam dredge, a scow provided with a longitudinal opening, and clam digging and elevating mechanisms operable through said opening, saidvelevating mechanism including a forward main conveyor, tracks mounted within said longitudinal opening at opposite sides of the rear portion thereof, said main conveyor having supporting wheels movable in said tracks longitudinally of the scow, means for vertically adjusting the digging mechanism and said conveyor including a hoist mounted on the deck of the scow and connected to the forward end of the frame of said conveyor, and vertically swinging arms pivoted at their forward ends upon the deck of the scow and having their rear ends pivotally connected to the forward end of the conveyor frame whereby the digging and elevating mechanisms are shifted longitudinally of the scow when vertically adjusted relative thereto, an auxiliary inclined conveyor extending into said longitudinal opening and arranged to receive the clams from the rear discharge end of the main conveyor, an inclined chute for leading the clams from the main conveyor to the auxiliary conveyor, and carriages movable on the deck of the scow and supporting said auxiliary conveyor for shifting movement longitudinally of the scow.

6. In a clam dredge, a scow provided with a longitudinal opening, and clam digging and elevating mechanisms operable through said opening, said elevating mechanism including a forward main conveyor, tracks mounted within said longitudinal opening at opposite sides of the rear portion thereof, said main conveyor having supporting wheels movable in said tracks longitudinally of the scow, means for vertically adjusting the digging mechanism .and said conveyor including a hoist mounted on the deck of the scow and connected to the forward end of the frame of said conveyor, and vertically swinging arms pivoted at their forward ends upon the deck of the scow and having their rear ends pivotally connected to the forward end of the conveyor frame whereby the digging and elevating mechanisms are shifted longitudinally of the scow when vertically adjusted relative thereto, an auxiliary inclined conveyor extending into said longitudinal opening and arranged to receive clams from the rear discharge end of the main conveyor, an inclined chute for leading the clams from the main conveyor to the auxiliary conveyor, and carriages movable on the deck of the scow and supporting said auxiliary conveyor for shifting movement longitudinally of the scow, a sorting table on the deck of the scow rearwardly of said longitudinal opening, and an inclined chute for leading the clams from the auxiliary conveyor onto said sorting table.

JAMES W. DANIELS.

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