US2177196A - Clamshell dredge - Google Patents

Description

ct. 24, 1939. 1 C, wlLLlAMs 2,177,196

CLAMSHELL DREDGE Filed Nov. lO, 1937 2 Sheets-Sheet 1 M am@ JD//my Oct. 24 1939. J. Q wlLLlAMs 2,177,196

CLAMSHELL DREDGE Filed Nov. 10, 1937 2 Sheets-Sheet 2 Patented Oct. 24, 17939 PATENT OFFICE oLAMsHELL DREDGE John C. Williams, Oakland, Calif., assignor to John C. Williams Corporation, a corporation ofl Nevada Application November y1o, 1937, serial No. 173,840

22 Claims.

This invention, a clam-shell dredge, is particularly designed for operation under conditions of submergence and is an improvement over copending application Serial No. 93,971, filed Au-r gust 3, 1936, which has issued under date of September 6, 1938, as'` Patent No. 2,129,158, for Clam shell dredge, which describes and claims a dredge of similar characteristics but does not includeany means for releasing the clam shell bucket from an object, such as a jutting rock which cannot be lifted from the bottom of the sea, and it also does not include any means for augmenting the inherent power of submergence when the depth of submergence does not create sufficient pressure to operate the power unit to the point of complete closure of thebucket, these latter `features being added to the instant applicationas themain features of improvement.

'I'he objectsand advantages of this invention are as follows:v

' First; to provide a clam-shell dredge, which under suitable degree of submergence Will operate Aautomatically to close the bucket upon reaching a sub-sea surface, through the influence of the water of submergence, and lock the clam-shell in closed position while being hoisted from the sea andfuntil manually released.

Second; to provide a device of the type outlined with. means controllable from the surface or other remote point, for Vreleasing the clamshell while submerged, froman object to which it has become' attached and which is too heavy to lift, and to permity re-operation thereafter through the medium of the water of submergence without raising the clam-shellto the surface.

Third; to provide a device as outlined in which r the means specified heretofore may be employed yto augment the power available through depth of submergence and which permits the dredge to operate automatically to the limit of the available power of submergence, the means being employed to increase the power to the value re-y quired for complete closing of the shell.

vOther objects and advantages of the invention Fig. 3 is a fragmentary view of a modied system' of bucket release.

Fig. 4 is a front elevation of the invention.

The scoops Ill and II are hinged at I2 and I3 respectively, to a head or deck I4 which has in- 5 tegral end wings I5 at its opposite ends coincidently forming closures and reinforcements. Sealing means for the cooperative jaws I6 and I1 consist of a resilient tube I3 set in one jaw I'I and having one side wall exposed for coop- 10 eration with the cooperatively related seal edge I9 of the other jaw It, and this tube I8 is iilled with a fluid which is maintained at a predetermined pressure above the pressure of the water of submergence, as by means of a cylinder 20 15 having the bottom in communication with the tube I8, as through a pipe 2 I, and having a piston 22 urged by a spring 23 and also by fluidof submergence through a passage 24.

Any ksuitable type of toggle or link mechanism may be employed as an operative connection to the prime mover for opening and closing the shells, and a positive acting and comparatively simple system is illustrated as consisting of brackets 25 and 26 for each shell, to each of 25 which is pivotally connected a link 27 by one of its ends, the other end of the link having a pivotal connection to a crank 28.

The shafts 29 and 30 each have one of the cranks 28 fixed at each end, and are each mounted in bearings 3| supported on the deck I4, and on each shaft is xedly mounted two gears 32 and 33 for cooperation with the respective racks 34 and 35.

These racks are dependent from, and integral with or affixed to opposite ends of the cross-head 36, and this cross-head is intermediately afxed to the upper end of the piston rod 3l, which has aflixed at its lower end a piston 38 operating in al cylinder '39 having a cylinder head 40, and 4G which piston rod, piston, and cylinder comprise 'a prime mover suitable for the purpose of operating the shells. Suitable packing for the piston rod against high fluid pressures both internally and extern'ally of the cylinder is illustrated in Fig. 2, and described and claimed per-se in copending application SerialNumber 173,837 filed Nov. 10, 1937, for Bearing seals, and consists of a seal chamber 4I formed yin the hub 42 of the cylinder head 40 and provided with opposed seal thrust faces 43 and 44, and a series of alternate resilient rings 45 and rigid rings I6 fill the space between the thrust faces under predetermined compression, and encompassing spiral springs 41 55 under predetermined tension compress the resilient rings against the piston rod.

The chamber fil is filled with a fluid, such as grease, and means is provided for maintaining a predetermined pressure on the grease of predetermined value above the instant pressure of fluid of submergence, and consists of a cylinder i8 having a piston 59 which is urged by a spring 59 and additionally urged by Water of submergence 5i by admission thereof during submer-Y gence through passage 52.

The clam shell is normally in open position as indicated by the dotted outlines 53 and 54, and each of the shafts 29 and 30 has a counterweight 55 afiiXed thereto for opening the shells and keeping themopen normally. The dredge is provided with a bail 56which has connections to the opposite ends of the deck I4, and a hoisting cable 51 has a Connection to the bail through the head 58 of a plunger 59 which is slidable through a bore 69 provided through the bail, and a combined spring seat and thrust collar 5I having an integral valveactuating arm 62 is fixed on the lower end of this plunger 59, and a conical coil spring 63 acts between the collar 5l an-d bail.

A valve 54 controls admission and discharge of iiuid to and from cylinder 39 and is connected to the cylinder as indicated at 65, and a hand lever 5,5 permits hand control of the valve for dumping the bucket. When the dredge is y-being raised or lowered, or when the cable 51 is drawntaut, the plunger 59 is retainedv in its uppermost position with the spring 93 fully compressed and with the collar 5i riding on the spring, and acting through the arm 52A and rod 61, retains valve arm 68 in the position indicated by the dotted outline 69, keeping valve 94 closed.

As the dredge is lowered to a sub-sea. surface and comes to rest thereon, slackingof cable 51 permits spring 63 to depress plunger 59, and with it, arm 52, which cooperates with collar 19 on rod 51 forcing the valve lever 68 down to the position shown in full lines, opening valve (ill and permitting water of submergence 5| to enter the cylinder 39 through the valve intake 1l, the water under the pressure of submergence forcing piston 39 with piston rod 31, cross-head 36 and racks 34 and 35up to the position shown in Figs. l and 4, air in the upper part of the cylinder above the piston being maintained at low pressure through breathing to the breather tank 12. On taking up slack in the cable 51, as for raising the dredge, the arm 52 is first drawn up, moving lever 68 to the dotted position 69, closing the valve 64 and locking the opposedshells I and H in closed position through the uid locky formed in the cylinder by the valve.

When the dredge is hoisted to the surface and ready for dumping, valveili is manually, or other Wise opened by means, such as' the lever 6,5, the

air in tank or compartment 12 under low pressure f by suitable valves 82 and 83.

may close over a jutting rock which could not be raised or broken off, or may attach itself to some other object which is too heavy to belifted to the surface, and under such conditions it is necessary to provide means for releasing the bucket from its trap.

AOne type of releasing means is shown in Figs. l and 4, in which a flexible tube 15 has a connection 15 with the lower end of the cylinder 39 through a valve 11, and this valve is controlled by'a lever '18, the tube 15, being wind.

able on a drum 19 and having a communicating connection through the drum shaft 89 with both ports of a pump 8i, these ports being controlled If these valves are moved to one position by means vof the con necting rod 34, kwater will be pumped from the sea 85 through pipe 88 and delivered through pipe 81 to tube 15 and if moved to the other position, water is drawn from tube 15, through pipe 88 and discharged to the sea 85 through pipe 89. 1

Fixed on one of the racks, as 35, is a cam plate 99 which is provided with end-connected cam grooves 9| and 92, the terminals being provided with latches 93, such as leaf springs. A bell-crank lever has one arm 99 provided with a roller 95 operating in the cam grooves andv is mounted on a shaft 95 which is mounted in a suitable bearing 91 which may be mounted on, or integral with the cylinder head '40, and the other arm 98 is connected to the valve 11 through a connecting rod 99.

Thus, as water enters the cylinder, roller 95 rides in groove 92, keeping valvef11 open, and as the piston reaches the end of itsstroke, the roller is vshifted through the lower angular groove to groove 9|, latch 93 passing the roller to the groove Si but preventing its return back through the angular groove, this movement closing the valve 11 to lock the admitted water against escape through the tube as the dredge is hoisted, and as cable 51 is drawn taut, valve 64 is also closed, forming a water lock against opening of 'the bucket. l

When the bucket is to be dumped, on opening valve 64 by means of lever 56, the water drains from the cylinder, the cam plate lowers with the piston, roller rides in groove 9i and finally shifts to groove 92 at the end of the stroke, latch 93 preventing return of the roller to groove 9|, and valve11 is again open.

In the event that the shells were prevented from closing completely by some obstruction and became locked on the obstruction so that the dredge could not be lifted, obviously vthe roller 95 would be located at some point in groove 92 with valve 11 open and the draw oncable 51 closes valve 64, therefore, to release the dredge, it wouldr merely be necessary to maintain tension on the cable 51 to keep valve Sd'closed, switch valves 32--83 to create suction in tube 15 and operate pump 8l to release the pressure in the cylinder until the dredge was released, raise the dredge partly and lower to another position and slack the cable 51 to open valvefi'd for another operation. Thus the dredge'may be opened at will unless the piston has reached the top of its stroke rand. the shells are fully closed, under which conditions openingwould not be required.

In the event that there isin'suicient head to operate the shells to close tightly, the Water vof submergence is permitted to actk on the piston to the limitof its power, after which the cable isji;

draw'ntaut and the valves 82 and 83 are shifted to deliver water under pressure through tube 15 andthe Wet pump 8| operated to complete operarto drainthe water Afrom the cylinder.

...Another method ofoperation isdisclosed in Fig; 3 and includes the ilexible tube 15 connected directly to the cylinder 39 and having a check valve preventing passage of water from the cylinder 39 yto tube 15. but permitting passage in the opposite direction, the upper end of the tube 15 being .connected to a pressure pump, as 8|, Fig.

f 1 ,1,for augmenting the pressure in the cylinder 39 when the head of submergence or hydrostatic i head isinsuflicient for complete operation of the erated manually from a remote point, such as the surface of the sea, for opening, as by a cable |05, is illustrated in Fig. 3.

With this arrangement, if the dredge cannot be raised,l it is merely necessary to draw cable 51 tautto close valve 64, then pull up on cable |05 to `open valve |03, and the water in cylinder 39 will drain into tank |0| until the dredge is released, after which cable |05 is released to close valve |03. The tank |01 should preferably be made of suflicient capacity for at least two releases, and a cock |06 is provided for draining this tank when it reaches the surface.

' Another'methodof releasing and augmenting the pressure can be incorporated in the system previously described in lconnection with Fig. 1, byv connecting a tube .I 01 to tank 12, or directly to the ybreather connection |08 inl. the cylinder head 40, and connecting the other end of this tube to a quired, by pumping the pressure in tank 12 to a value' as great or greater than the value of the pressure of 'submergence or hydrostatic head while'valve 64 is kept open, the piston 38 will be forced down, and upon release of this pressure in vthe tank, thev dredge will operate in its normal manner.

This system, when using only the tube |01 and dry pump |09, has the advantage of extreme simplicity, `of requiring no valves, and of being a dry system, and when so used, valve 11 with its asso- Aciated parts 'including cam plate 90 is not required, and any type of opening and closing mech'- anism for valve 04 may be employed which will;

' under pressure is requiredto work against the ferginstanca with,valvelllv closed, pressure in,

tank 12 delivered through conduit |01 from pump |09, and suction built up in conduit 15 by Wet pump 8| Will act on both sides of the piston for release. Conduit |01 and tank 12 must always be maintained dry. Reversing the arrangement augments the power in the cylinder, additively over the available power of the hydrostatic head.

It will be understood that `variations in construction and arrangement of parts, which variations are consistent with the appended claims, may be resorted,l to without detracting from the spirit or scope of the invention, or sacrificing any of the advantages thereof.

I claim:

.1. In combination, a clam-shell bucket and a prime mover mounted thereon, an operative connection between said prime mover and said bucket for closing said bucket; means for admitting Water of submergence to said prime mover for operation thereof when the bucket reaches a subsea surface and for locking admitted water in said prime mover as said bucket is raisedfrom said sub-sea surface; counterweight means urging opening of said bucket; means for releasing said admitted water at will after said bucket has been removed from said water of submergence; and releasing means and remote control means therefor for releasing and removing said admitted water for opening said bucket while said bucket and prime mover is submerged.

2. A structure as claimed in claim 1; said releasing means including means for augmenting the available power of said water of submergence when in itself deficient in pressure to fully and efficiently close said bucket.

3. In combination, scooping means having cooperative scooping elements; a prime mover mounted on said scooping means; an operative connection between said prime mover and said scooping means; cooperative sealing means on the respective scooping elements; means for building up the internal pressure of said sealing means as the external pressure is increased, to a value greater than the external pressure; means for admitting water of submergence to said prime mover for operation thereof to close said scooping means when said scooping means reaches a sub-sea surface, and for locking the admitted water against escape upon raising of the scooping means from said sub-sea surface; means associated with said prime mover and remoter control means therefor, for selectively, releasing and removing said admitted water for opening the scooping means, or, for augmenting the available power of the water of submergence in the event of deficiency in pressure of submergence, while said prime mover is submerged.

4. In combination, a clam shell bucket having a water-of-submergence-actuated prime mover mounted thereon and an operative connection between said prime mover and said bucket for closing said bucket; counterweight means associated with said bucket for opening said bucket; control means .for admitting water of submergence for operation of said prime mover when said bucket reaches a sub-sea surface and for locking admitted water in said prime mover when said bucket is raised from said surface to lock said prime mover against retrograde operation; auxiliary power means and remote control means therefor associated with said prime mover and selectivelyl operating to release and remove admitted water from said prime mover to open the bucket, or, to augment the available power 75,'

of said water of submergence vwhen deficient in :pressure to efficiently close and lock the bucket, while said prime mover is submerged.

5. In combination, a submersible device and a .prime mover mounted thereon and operated through the medium of uid in which said device and .prime mover are submerged; control means controlled by the weight of the submersible device and prime mover and controlling operation of said prime mover forone operation of said device; manually-controlled means for controlling operation of said yprime mover for another operation of said device when said de- .vice and prime mover are removed from said f luid; and remotely controlled auxiliary power means associated with said prime mover for operation thereof for either operation at will while said device and prime mover are submerged in said fluid.

6. In a prime mover having a mounting having a `hoisting cable, and operated under conditions of submergence by the fluid of vsubmergence and control means controlled by said hoisting cable for controlling operation of said prime mover for one cycle of operation; auxiliary power means and remote control means therefor associated with said prime mover for retractively operating said prime mover while under conditions of submergence, at will.

7. A structure as claimed in claim 6; said auxiliary power means and control means therefor being controllable at will for alternatively operating to augment the power for operation of said prime mover after the total available power of said fluid of submergence has been expended, for completing said one cycle of operation of said prime mover.

8. A submarine dredge comprising a clamshell buckethaving cooperative scoop elements; a cylinder having a piston and mounted on said bucket; operating means connecting said piston with said scoop elements; a valve for controlling admission of water in which said dredge is lsubmerged, to one end of said cylinder; a receiver in communication with the other end of said cylinder forming a breather chamber; means for opening said valve when said dredge reaches ak sub-sea surface and closing said valve when said dredge is raised from saidsurface; manual-1 ly operated means operable when said dredge has been removed from the water of submergence for discharging admitted' water from said cylinder; counterweight means urging said bucket to open; said bucket being iiuid-locked in both its open and closed positions; auxiliary power means and remote control means therefor associated with said cylinder for selectively, releasing and removing admitted water from said cylinder to open the bucket, or, foraugmenting the power of the water of submergence when deficient to close the bucket, while the cylinder is submerged.

9. A submarine dredge comprising; scooping means having cooperative scooping elements; a fluid-actuated prime mover mounted ony said scooping means; an operative connection between said primemover and said scooping means for opening `and closing said scoopingY means; and' weight controlled means operable when said scooping means reaches a sub-sea surface for admitting fluid ofl submergence to said prime mover for operation thereof to close said scooping means; and auxiliary power means and remote control means therefor associated with said prime mover for selectively, releasing and removing admitted water from said prime mover to open the bucket, or, to augment the available power of said uid of submergence when decient to close the scooping means, while the dredge is jected to a `predetermined pressure and addi-A tionally subjected to the pressure of the fluid of submergence maintaining the internal resistthe combined pressure of the fluid of submergence and said predetermined pressure to maintain said'resilient sealing means effective against` its external fluid pressure.

l1. In adevice for submarine operation; a`

fluid-operated prime mover; a valve for controlling passage of fluid of submergence to and from said prime mover for actuation thereof; and

- valve controlmeans mounted on' said device and actuated upon contact of said device with a subsea surface for opening said valve for admission of iiuid of submergence to said prime mover for operation thereof and for closing said valve as said device is urged to raise above said surface, for hydraulically locking said prime mover against further operation; auxiliary power means and remote controlmeans therefor associated with said device for selectively, releasing and removing admitted water from said prime mover for reverse operation thereof, or, for augmenting the available power of the'water of submergence when-deficient to complete an operation of said device, while the device is submerged.

ance of said resilient material at a value equalvto 12. A submarine dredge comprising scooping means consisting of cooperative scooping elements and counterweight means Anormally maintaining said scooping elements in open position; a cylinder mounted on said scooping means; a

piston operating within said cylinder and an op-` erative connection between said piston and saidV scooping elements; a first valve for controlling admission of duid of submergence to one end of said cylinder and hand control means for openl y ing said valve; means for opening said valve when said dredge reaches a sub-sea surface and for closingr said valve as said dredge is lifted or urged to lift from said surface; a breather compartment` in communication with the other end of said cylinder; a second valve for controlling communication with said one end of said cylinder; auxiliary power means and remote control means therefor associated with said second valve for releasing and removing water of submergence from said cylinder while said dredge is submerged to release said` cooperative scoop elements.

`13. A structure as claimed in claim 12; said remotely controlled means including Water-delivery mean's for augmentingfthe power of the water of submergence lwhen decient for complete closing of said scooping means.

14. A structure as claimed in claim 12; control means associated' withsaid dredge closing said second valve when said scoop elements are completely closed and opening said valve coincident.

sociated with said pump for changing the con; 75:

nection of said conduit selectively to the intake and discharge of said pump.

16. A structure as claimed in claim 12, said remotely controlled auxiliary power means comprising a pump having a communicating connection with said second valve.

17. A structure as claimed in claim 12, said auxiliary power means and remote control means therefor comprising a pump having a communicating connection with said second valve; control means associated with said dredge closing said second Valve when said scoop elements are in their final closing movement and opening said second valve during the iinal opening movement of said scoop elements.

18. A structure as claimed in claim 12; said auxiliary power means and remote control means therefor comprising a pump having an intake and a discharge and having a connection to said second valve and valve means associated with said pump for changing said connection selectively to the intake and discharge of said pump; and control means associated with said dredge for closing said second valve when said scoop elements are operating through their final closing movement and opening said second valve during the final opening movement of said scoop elements.

19. A structure as claimed in claim 12, said auxiliary power means and remote control means therefor comprising a dry pump and a wet pump respectively connected to said breather compartment and to said second valve, and means for closing said second valve to water lock said piston in the closed position of said scoop elements.

20. A structure as claimed in claim 12; said auxiliary power means and remote control means therefor comprising a dry pump and a wet pump respectively connected to said breather compartment and to said second valve, and means for closing said second valve to water lock said piston in the closed position of said scooping means, and consisting of a control element associated with said piston, closing said second valve when said scooping elements are passing through their final closing movement and opening said valve when said scooping elements are opened and retaining said valve open during the closing operation of said scooping means.

21. In a submersible device having a water-ofsubmergence actuated prime mover for operation thereof, and a hoisting cable and a connection therefor to said device; means for controlling operation of said prime mover comprising a valve; said connection comprising a slidably mounted plunger; a spring continuously urging to depress said plunger against the restraint of said cable; an arm on said plunger and an operative connection between said arm and said valve for maintaining said valve closed when said cable is restraining said plunger against the urgence of said spring and for opening said valve when said cable is slacked to free said plunger for depression.

22. A structure as claimed in claim 21, said operative connection comprising a connecting rod slidably operating through said arm and having a collar for cooperation with the underside of said arm and having a spring seat at its upper end and a second spring operating between said arm and said spring seat; a hand lever for manual operation of said valve and connected to said connecting rod; said second spring permitting operation of said hand lever to open said valve while said plunger is fully restrained by said hoisting cable.

JOHN C. WILLIAMS.

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