US2963870A - Counterbalanced unwatering apparatus - Google Patents

Description

Dec. 13, 1960 M. MACHOL ETAL COUNTERBALANCED UNWATERING APPARATUS 4 Sheets-Sheet 1 Filed Feb. 20, 1959 ii -il INVENTORS at, MR. MA

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Dec. 13, 1960 M. R. MACHOL ET AL COUNTERBALANCED UNWATERING APPARATUS 4 Sheets-Sheet 2 Filed Feb. 20, 1959 INVENTORS C A RaAMs &, M. R MAcHo\.

g r MMI-EJZUL ow E n Dec. 13, 1960 M. R. MACHOL ET AL 2,963,370

COUNTERBALANCED UNWATERING APPARATUS Filed Feb. 20, 1959 4 Sheets-Sheet 5 Pie. 6.

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INVENTORS CA. REAMS ATTORNEYS MACHOL.

Dec. 13, 1960 M. R. MACHOL ETAL 2,963,870

COUNTERBALANCED UNWATERING APPARATUS Filed Feb. 20, 1959 4 Sheets-Sheet 4 Q #2 I Q m m m m Zo F x i 3% l; :l/ g;f

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INVENTORS C.R.REAMS @MRMACHOL BY WM ATTORNEYS United States Patent COUNTERBALAN CED UNWATERING APPARATUS Morris R. Machol, New York, N.Y. (1819 G St. N.W., Washington 6, D.C.), and Clinton A. Reams, 192i? 8 St. N.W., Washington, D. C.

Filed Feb. 20, 1959, Ser. No. 794,766

12 Claims. (Cl. 61-65) This application is a continuation-in-part of applicants copending application Serial No. 324,778, filed December 8, 1952, and now abandoned.

This invention relates to hydraulic means for elevating and lowering heavy bodies, particularly floating objects such as vessels and barges, to remove the object from the water and place it upon a cradle or other support which may be provided with one or more wheeled trucks to enable it to be moved with its load over the land.

There are four well known means for lifting a vessel or other floating object out of the water in order to examine or work on its underwater body, including graving docks (usually called dry docks), floating dry docks, marine railways and vertical hoists. Each of these is suitable for certain conditions but all four are extremely expensive to build and to operate. Each requires large quantities of power which is only used a small part of the time (this being one reason for the costly operation); and each of the first three are slow of operation. The vertical hoist, which has been used only in small capacities, is faster by virtue of using proportionately larger amounts of power.

The purpose of this invention is to provide means for unwatering floating objects which will cost much less to build than the conventional means, which will require a minimum of mechanical effort, will need little or no power from an outside source (stream or electric) and will require only a small fraction of the operating and maintenance costs of the conventional types and which will raise the vessel in a very short time. By unwatering is means removing floating objects from the water and supporting them otherwise.

This invention is a combination of well known and thoroughly tested principles of mechanics which produces an unwatering facility that costs much less to build, costs very much less to operate, requires a minimum of mechanical effort, and will operate in a fraction of the time needed for the conventional methods.

The simple principle on which this invention depends is that water from an elevated tank, which can either be filled by a hydraulic ram or small pump or from a public water supply system, is used so that its weight will counterbalance the weight of the vessel.

A preferred embodiment of the invention is shown in the accompanying drawings, wherein Figure 1 is a side elevation and Figure 2 is a plan view of the device showing the lifting platform raised from the water and the counterweight tank in lowered position. These figures also show in dotted lines the platform lowered beneath the water to receive or discharge a vessel or other floating object, the counterweight tank being likewise shown in elevated position.

Figures 3 and 4 are respectively a plan and side elevation of the control device for the power motor and valves which control the flow of water into and out of the counterweight tank.

Figure 5 is a side elevation of the platform stop and tipping means.

Figure 6 is a schematic plan view showing an arrangement which utilizes our unwatering apparatus to position a plurality of ships in dry storage on the land.

Figure 7 is an end view of the arrangement of Fig. 6.

Figure 8 is a diagrammatic view similar to Fig. 2, showing an elongated tank for use with large ships; and

Figure 9 is a diagrammatic elevational view looking toward the left side of Fig. 8.

In the apparatus shown in the drawing, a lifting platform 10 is movably supported by two or more pairs of columns 12, pivotally mounted at their lower ends on fixed supports 14 carried by a suitable underwater foundation 16, and hinged to brackets 18 on the under side of the lifting platform, near the edges thereof, to cause the lifting platform to maintain a horizontal position when being raised from or lowered into the water, as shown in Figure l. The vessel or other object 20 to be lifted from the water is readily chocked up on the lifting platform when floating above it in alinement therewith by raising the platform and cradle 22 until the latter engages beneath the bottom of the floating object, as by pulling in on the pair of cables or chains 24 which are secured by fastenings 28 to the two inner columns of two of the pairs of supporting columns 12 near their upper ends where they are pivoted to the lifting platform.

The cables or chains 24 may be continuous and have their inhaul sections passing shorewards and connected to the counter-balancing and control means and their outhaul sections 26 reeved around sheaves or sprockets 30 rotatably supported on underwater pedestals on the water side of the lifting platform and around sheaves or sprockets 32, rotating on fixed journal supports on the shore side of the lifting platform, as shown in Figures 1 and 2. Each inhaul section of the cables 24 passes over two spaced guide pulleys 34 and 36 between which is a slack take-up pulley or sprocket 38 provided with a brake of any suitable type. Two guide pulleys 40 are provided on the land side of the lifting platform for supporting each outhaul section 26 of the pair of cables 23 near where it enters the water. The cables or chains 24 are actuated by means of a control cylinder 42 having a piston provided with a crosshead 44 to which the inhaul and outhaul sections are connected at their shore ends by means of clamps 46 (see Fig. 3). A counterbalance cable 48 is also attached to the crosshead 44 for supporting the greater part of the weight of the platform and load as it is lifted or lowered.

The cylinder 42 may be operated in any desired way to supply the power needed to actuate the lifting cable's, but preferably water from the elevated tank 50 is used to act against the piston within said cylinder although water carried by the piston rod 84 under pressure from the local water supply system may be used for this purpose. Water from either source is admitted through pipe 52 to one end or the other of the cylinder through a four way valve 54 and the pipes 56, which are so arranged that when one is connected to the water supply 52 the other is open to a drain pipe. The same water supply may also be used to fill the elevated water storage tank 50 or a special pump may serve this purpose.

Manual actuation of the valve 54 permits the speed of operation of the cylinder and lifting chains to be controlled to correspond to the time necessary to fill or empty the counterbalancing tank 58 to which the free or inshore end of the counterbalance cable 48 is attached after passing under the guide pulley 60 at the foot of the storage tank tower and the guide pulley 62 at the top of the tower beneath the storage tank 50. A flexible pipe 64 leads from the bottom of the storage tank 50 to the counterbalance tank 58 for filling the latter, a suitable '3 valve or valves 66 being provided for controlling the flow from the storage tank.

The counterweight tank 58 when empty and the platform 10 and columns 12 in lowered position approximately balance each other. The vessel or other object 20 in its lower position is supported by the water in which it finals Each inch it is raised reduces the bouyant effect of the water and increases the weight or pressure on the platform. Water draining from storage tank 50 into counterweight tank 58 increases the weight of the latter, and the counterweight tank on the one hand and the platform and its load while partially submerged on the other hand approximately balance each other and the vessel .comes out of the water just as fast as the water is released into the counterweight tank.

When the platform 14) is at its lowest position, the speed with which the ship rises is roughly half that of the movement of the chain connection 24. As the platform approaches its upper position the vertical speed of the vessel becomes proportionately less until at the top position it has no vertical movement. Therefore the pull on the chain, which may be increased'at first, must be thereafter reduced as the vessel rises or the speed will become excessive as the platform hits the dock. This reduction of pull is accomplished in three ways; by closing valves 66 from the store e tank; by releasing water for the counterweight tank '53 through valves inits bottom; by turning valve 54 to apply pressure on the end of hydraulic cylinder 42 and the side of the piston therein away from the platform; and by using the brakes at tached to sprockets 38. The speed with which the vessel can be raised is only limited by the size of the valves and the speed with which water can be drained into and out-of counterweight tank58. When the platform is empty and the tank is empty, water pressure on the end of hydraulic cylinder 42 furthest from the platform, acting through the backhaul chains, will pull the platform down. Thus a ship resting on the platform can be launched by the proper control of the amount of water in counterweight tank 58.

When the platform is in its top position, even the weight of a vessel exerts no horizontal thrust to rotate the columns outwards on their lower axes, but as they move outwards the thrust increases as the platform lowers and must be counteracted. Without a vessel, the weight of the platform will not balance the weight of the counterbalance tank until the platform has been moved some distance out and down. For this purpose two hydraulic'cylinders 68 are provided, arranged as auxiliary pushers, their pistons being actuated 'by water from the tank tower controlled by a valve. The pads 70 on the outer end of the pistons engage the pads 72 on the platform for this purpose. also engage or disengage locking pins 76 pivoted at 78 with lock plates 8% in the manner shown in Figure 5 to release the platform before moving it. As the platform The pads have earns 74 which moves out and down its weight becomes effective to ballance that of the counterbalance tank and the chains 24 suifice to control its movement.

This invention has many advantages. The only power required to operate the lifting platform is that to run a pump to supply sea water enough to keep storage tank 50 filled in those places where a public water supply is not available, or is too expensive.

Two, three, four or more pairs of columns 12 can be used for whatever length of platform is desired; and the ship may be hauled out sidewise, or the bow of the ship can be pointed inshore lengthwise of the platform and lifted out of the water endwise. In either case where the drawings show only one pair of columns 12 there can be as many pairs of columns extending out into the water or along a slip as are needed to support the length of platform desired.

The discharged water from the counterweight tank 58,

led to the area'of the platform foundations, will provide an outward current of water that will help to keep that area free from silt.

When a vessel or other floating object is resting in checks on the platform in the water and is ready for the lift to begin, it exerts no weight on the platform, since it is afloat and entirely supported by the water. The counterbalance tanks weight when empty equals and balances the weight of the platform and columns. If, at the start of the lift, the columns are at an angle of 60 with the horizontal, the chain 24 will move two inches while the platform rises one inch; Therefore, for each pounds additional weight onJ-the platform as the ship rises from the water, only 50 pounds of water will be needed in the counterbalance tank.

If the cable 48 from this tank, instead of being fastened to the crosshead as shown, is fastened at the lower sheave 60 and then reeved around another sheave on the crosshead and from there over the lower sheave 60, the tank would move twice the distance that the crosshead moves and only 25 pounds of water would balance 100 pounds ofship.

The smaller the angle of the supporting legs the greater the discrepancy between the vertical distance travelled by the platform and the distance (not quite horizontal) travelled by the chain. If the chain moves twice as fast as the platform rises vertically the strain on the chain is hal the weight of the ship. So it becomes desirable to keep. the angle as small as possiblethe deeper the foundations for support of the pillars the less the angle of the pillars in the bottom position.

Two factors control this depthone the amount by which the depth of the water exceeds the draft of the ship. If the hoists design intends that it only be used during the upper half of the tide run-one half of the total tide will be added to the depth.

If it be assumed that the ship to be raised has a displacement of 5000 tons, without cargo or fuel it might Weigh 3600 tons. Be it assumed further that the ratio of chain travel to vertical travel of the platform is 2 to 1, a ratio which may easily be provided. Near the .top of its swing the vertical rise of the platform is very small in proportion to the movement of the chain, so that the ratio of the weight of the platform to the tension on the platform is very high. But when the platform is near its lower position, the ship is largely waterborne, and there is very little Weight on the platform. If the ship draws 24 feet of water, when it is half out of water the weight on theplatform should be in the neighborhoodof 2000 and the travel ratio of chain to platform about 10 to 1. At that point the strain on the chain should be near its maximurn and would be about 200 tons. In other words, as the ship rises, the increase in the proportion of its weight which must be supported from the chains is largely oifset by the mechanical advantage resulting in the increase of the ratio between the distance travelled by the chain and the vertical rise of the platform.

As the platform rises, each one degree rotation of the columns gives almost the same movement of the chain but each degree rotation of the columns gives less and less lift of the vvessel until when the columns are vertical the lift is zero. As the ship is raised toward the top of the lift its weight rests entirely on the platform, but less and less weight of Water is needed in the tank 58 to balance it because of this change in angle. Thus in order to maintain a balance between the weight of the ship and the weight of the counterbalance tank 58, it is necessary that during the first part of the lift water must flow into the counterbalance tank to increase its Weight while during the latter part of the lift water must drain from the counterbalance tank to decrease its weight.

To accomplish, this automatically the invention includes a tension meter, as illustrated in Figures 3 and 4. This comprises a flanged metal plate or disc 82 fixed on the end of the piston rod 84 which slides through the crosshead 44. A housing or yoke 86 to which the wire cable 48 is attached projects tom the crosshead 44 and contains a spring 88 surrounding the piston rod between the disc 82 and the crosshead which is under compression when the weight of the vessel on the platform is less than that of the counterbalance tank as shown in Figures 3 and 4. A heavier compression spring S is arranged in the housing 86 between the disc 32 and the fitting 92 into which the end of the wire rope 48 is secured by means of a swivel 94. These two springs 90 and 88 limit the travel of the disc 82 in relation to the housing and crosshead 44 and transmit the pressure on the piston to them and to the chains 24. Electric contacts 96 attached to the housing 86 are contacted by the disc 82 at the two limits of its movement and act to open and close the valves that permit flow of water into and out of the counterbalance tank. With the disc in its middle position neither contact is closed and all valves are closed. Thus the balance between the pull on the cable due to the Weight of the counterbalance tank and the pull on the chains due to the weight of the ship on the platform is maintained and effected automatically within small limits determined by the tension of the springs. If the tension of the heavier spring 90 is 50 pounds more than that of the lighter spring 88, then the imbalance (or unbalance) will not exceed 100 pounds.

A drum 98 actuated by an electric motor 100 may be substituted for or may augment the cylinder 42. With a 50 pound spring tension mentioned above, the drum need only exert a pull of 101 pounds to raise or lower a ship regardless of how many tons it weighs, and only a very small electric motor is needed. The speed with which the ship can be raised and lowered is limited only by the size and number of valves controlling the flow of water into and out of counterbalance tank.

A site may be selected which it not too far away from high ground on which there is a natural source of watera pond, lake, reservoir or even a stream. One obvious example would be the Hudson River running past the Palisades on the Jersey shore. In such a situation the upper tank or tanks 50 would be eliminated and replaced by the outlet end of a pipe laid from the water supply describedto discharge into the rectangular trough. This would eliminate pumps and the power to drive them and also eliminate the time taken to pump water into the tanks.

When such a distant water source is available, the structure supporting the rectangular trough may be built tall enough to allow a greater vertical travel of the trough. This could be made 100 feet and the total travel of the crosshead 44 could be made 20 feet. If the wire cable 48 between the pulley 60 and the crosshead 44, is then reeved over a series of pulleys like a rope is reeved in a block and fall, the additional to 1 reduction in speed will make the strain on cable 48 (and the weight of water needed in the tank) 40 tons, to balance a 5000 ton ship.

The embodiment of our invention thus far described comprises a platform that will raise a small ship-one not over 75 or perhaps 100 feet in length. A longer ship-perhaps 500 feet-would require a longer platform and a number of towers and tanks would be needed. But this would require absolute control of the rate of flow of water to insure that each tank would fill or empty at exactly the same rate. This would be difficult if not impossible to accomplish. If the tank at one end filled faster or slower than the other end-one end of the platform would be further out and further down. This twisting strain might well wreck even a sturdy platform and the ship on it.

We meet this situation by substituting one long rectangular trough for the tank 58. This trough may be provided with transverse baflles 58a to prevent a sudden surge of water to any point which may temporarily be slightly lower than another. It can be filled either from a higher trough, from tanks or from an outside source of water. As many piston and cylinder engines as desired may be provided, each connected by cables to both the platform supporting columns and to the counterweight suspension means. To keep the rectangular tank moving evenly at both ends two shafts 101 will be run parallel to the length of the tank, one above and one below. On the end of each shaft is a sprocket with a chain 102 engaging the upper and lower sprockets. The chains would be fastened to the end of the tank at 103. There would be little or no strain on the chains since water in the trough would constantly seek its own level.

One of the shafts 101 may provide a convenient method of preventing excessive speed, since a gear on one end thereof may be connected through a suitable speed increasing gear train to a governor which regulates the flow of water into and/or out of the tank 58, or other means for regulating the speed of movement of said tank.

A marine railway or dry dock can only handle one ship at a time and the facility is tied up until repairs are completed which may be from a day to many weeks.

The hoist herein described can be coupled to a transfer system and service an entire fleet of ships, lifting each ship out of the water and moving it to a prepared place on shore in a matter of minutes.

The platform 10 is then equipped with a set of transverse rails or hearing races -preferably bearing races, since bearings would require much less weight than wheels. Resting on top of platform 10 is the platform 111 on which the ship and its cradle rests. There are bearing races 112 on the bottom of this platform and bearings 113 between the two sets of races in retainers or cages. Alongside the platform 10, in its top position, and running parallel to the center line of the ship is a set of rails 116. Another plat-form 117 is equipped with supporting axles and wheels to run on the rails 116. On the top of the platform 117 is another set of bearing races to match the bearing races on platform 10. At various stations along the rails 116 are sets of rails 118 running at right angles to rails 116. A wheeled platform 119 runs on the transverse rails 118, and bearing races 121 on top of platform 119 match those on platform 10.

Between platform 119 and the rails 116 and between platform 117 and platform 10 in its upper position there are stationary platforms 122 and 124 respectively, equipped with bearing races 123 and 125.

Docking a ship proceeds as follows: After platform 10 is in its top position and locked, the platform 111 and ship is rolled on bearings 113 over platform 124 onto platform 117 utilizing an additional set of caged bearings 126 and plat-form 117 is then moved on its wheels until it is alongside platform 119 in its prepared position. The ship supporting platform 10 is then rolled on the bearings 126 onto platform 122 and thence by means of caged bearings 127 onto platform 119. Platform 117 can then be rolled :back to pick up another ship and move it to any one of several other prepared platforms similar to 119.

In this way the hoist can lift one ship after another and each can be easily and quickly moved to a position on shore, where it may be stored out of the water'with no fouling of bottoms and no cluttering up of the Water or stream. Any work needed can be done on the underwater body of the ship in the dry.

We claim and desire to secure by Letters Patent the following and equivalent arrangements of deck, platform, columns and lifting means, with our control apparatus:

1. In an unwatering apparatus the combination with a stationary dock of a vessel supporting platform movably mounted alongside said dock on spaced right columns pivoted at their bases to underwater supports and hinged at their upper ends to the underside of said platform, means for lowering and raising said platform into and out of the water while maintaining it horizontal by tilting said columns, an elevated water source alongside said dock, a counterweight water tank and means for movably suspending it at a lower level than said water source, means for discharging water from said storage tank into said counterweight tank and means for discharging water-'out of saidcounterweight-tank, control means' for. said water discharging means, a connection betweenthezcounterweight tank suspending means and the platform lowering and raising means through which the weight-of'said counterweight water' tank and the water thereincounterbalance'thatof said platform and itsload, and means responsiveto' changes in the tension on said connection for operating the-water discharging control means to maintain a properbalance between said counterweight tank and'said platformduring lowering and raising of: the-latter. r

2. An unwatering apparatus 'assetforth in claim 1 wherein the means for lowering and raising the vessel supporting'platform includes a cylinder and piston engine, a, connection between said engine and platform, and means-for supplying fluid pressure to said cylinder on either side'ofthe piston to control the direction of movement of said platform.

3. An unwatering apparatus asset forth in claim 1 wherein the connection'betweeu the counterweight tank suspending means and the platform lowering and raising means includes a rotatable member, braking means associated with said rotatable member, and control means for actuatingsaid braking means.

4. An: unwatering apparatus as set" forth in claim 1 wherein the-platform raising and lowering means, the counterweight water tank suspending means and the connectionbetween said raising andlowering and-suspending means include aflexible-cable and power means associatedwith said cablefor pulling it in either direction.

5. In a control device for a lifting platform as set forth in claim 1 having a moving cable in the connection between said counterweight tanks and columns and a member reciprocating therewith, a reciprocating power means, a collar firmly affixed to the power means, spaced limit stop members moving with" the reciprocating member, these limit stop members being positioned to limit the travel of'said collar withrespect to the moving cable, and an electric circuit including means actuated by said travel of the collar to control the valv'esallowing water to flow into'and out of the counterbalancing tank;

6. A control device for a lifting platform asset forth in claim 1 having a cable in the connectingmeansbetween the counterweight tank. audi platform, a drum around which said cable passes, and anelectric motor connected to the drum for controlling lifting and lowering movement of said platform.

7. The combinationof a stationary dock and platform pivotally mounted on pairs of upright columns pivoted at-their bases for tilting away from said dock, an elevated storage water tank, a counterweight tank and means movablysuspending it below saidstorage tank, flexible means for connecting the tank suspending means with said columns for retaining said platform against saiddock and counterbalancing. said platform when tilted away from said dock, automatic. control, means for releasing water from;'saidstorage. tank into: said counterweight tank and for releasing water. from said counterweight tank for balancing the weight of a movable body on saidplatform when said platform is tilted, power actuating means associated with said flexible connecting means for operating it in either; direction of pull,.independeut control means for. saidpower actuatingmeans, a tension meter connected: between two contiguous endsv of said flexible connecting means comprising a-link connected at one end to an end. of said flexible connecting means, a slide guided for movement withrespectto the free end of said link, said s-lide havingastop atone endand its other end connected-- to'the other contiguous end of said flexible connectingmeans, spring'meansmountedin said-link and engaging said slideto position saidstop normally-between the ends of saidlink, and contact-members mounted on said-link adjacent its ends imposition to be engaged by said slide uponsaid stop approaching. either end-of said link under achange in the pull on said flexible connecting means sufiicient to flex. said springs and cause relative movement of said'slide with respect to-said link.

8. The combination of a stationary dock and a platform pivotally mounted on pairs of upright columns pivoted attheir bases for tilting away from said dock, an elevated storage water tank, a counterweight tank and means movably suspending it belows aid storage tank, flexible means for connectingthe tank suspending means with said columns for retaining said platform against saiddock andcounterbalancing saidplatform when tilted away from saiddock, automatic control means for releasing water from said storage tank into said counterweight tank and for releasing water from. said counterweight tank for balancing the weight of a-movable body onsaid platform when saidplatform is tilted, power actuating means associated with said flexible connecting means for, operating itin either direction oflpull, independent-control means for said power actuatingmeans, a piston and fluid pressure cylinder fixed to said dock, a thrust connection between said piston and flexible connecting means adaptedto move the latterin either direction of pull, a member in; said thrust connection having limited sliding move ment with respect to said flexible connecting means, and means associated therewith operating at the ends of said sliding movement for actuating said. automatically controlled: water releasing means.

9; Apparatus-of the kind set forth in claim 1 wherein the connection between the counterweight tank and platform comprises a flexible cable, a drum around which the cable passes, and an electric motor to operate the apparatus through the drum.

10, Apparatus as claimed in claim 1 in which the suspension means for the. counterweight water tank comprise two parallel rotatable shafts, mounted longitudinally of said tank,: one'above the uppermost and one. beiow the lowermost limits of its path of travel, sprocket wheels fixed to the'ends of each shaft, andza. chain at each end of the tank connecting the sprocket wheels. on the upper shaft to those on thelower shaft and the adjacent end. of the counterweight tank.

11; Apparatus as claimed in claim 10 inwhich one of said sprocket wheels drives a governor through speed increasingigearing and said governor controls said water discharging means.

12; Apparatus as'claimed in claim 1 in; which said counterweight" tank isprovided with transverse. baflies to inhibit longitudinalsurges of water therein.

References Cited in'the file of this patent UNITED STATES PATENTS 1,487,742 Hill Mar. 25, 1924 2,392,081 Crandall Jan. 1, 1946 FOREIGN PATENTS 365,935 Great Britain Feb. 10, 1932 115,020 Sweden Sept. 18, 1945

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