US2213375A

US2213375A - Lifting buoy

Info

Publication number: US2213375A
Application number: US176432A
Authority: US
Inventors: Barna Andrew
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-11-26
Filing date: 1937-11-26
Publication date: 1940-09-03
Anticipated expiration: 1957-09-03

Description

Sept. 3, 194i).

A. BARNA LIFTING BUOYv Filed NOV. 26, 1937 5 Sheets-Sheet l II'I III

IDI

Sept. 3, 1940.

A.BARNA LIFTING BuoY Filed Nov. 26, 1937 3 Sheets-Sheet 2 Sept. 3, 1940. A BARNA 2,213,375

LIFTING BUOY Patented Sept. 3, 1940 1 UNITED STATES animsv PATENTif'orric1:

2,21a754 LIFTING BUoY Andrew Barna, South Clnicagn,jllllV Application November 26, '1937, Serial No. l76,432

sclaims. (ci. 114-49) v This invention relates to improvements in lifting devices, herein termed lifting buoys which are intended for use in elevating to the surface of the Water vessels and the like which 5 have been sunk and which lie at the bottom of the sea, or on the bottoms of rivers, harbors and lakes, or other bodies of water. lLifting devices have hereto-fore been used for this purpose but, sofar as is known, they have comprised collapsible containers adapted to be attached to a` sunken vessel and to be thereafter inflated by compressed air or the like supplied thereto through hose connections leading from an air compressor carried by a boat or l5l scow on the surface of the water. This practice has made it necessary to employ an air compressor of large capacity on the boat or scow and to use a boat or scow of considerable size in order to carry on the necessary operations at the surface ofthe water. A large amount of equipment hastherefore been required in order to use lifting devices of this prior type and their use has further been unsatisfactory because a leak in one of the collapsible containers or in the hose connection leading thereto has been likely to render the whole system inoperative where a plurality of lifting devices are attached to the sunken vessel and inflated by the same air compressor.

The principal object of the present invention is to overcome the above mentioned difficulties and others by providing an' improved lifting buoy having embodied therein means for storing a quantity of compressed air or other iiuid which may be released to inflate a collapsible container after the lifting buoy has been attached to the sunken vessel. These improved lifting buoys may therefore be charged with compressed air or the like on shore, or elsewhere, before being 4o taken to the place where they are to be carried down by a diver and attached to the sunken vesesl. The apparatus which must be in position at the surface of the water above the sunken vessel is thus comparatively limited. A further 4 object of the invention is to provide an improved lifting buoy adapted to be attached to a sunken vessel and comprising an inatable memberk capable of being iniiated by a supply of compressed fluid carried by the lifting buoy, in combination with means for releasing the compressed fiuid supply through a connection leading to the surface of the water when it is desired to bring intooperation the buoyant action of the device. Still another object is to pro- 55 vide a lifting .device of the type referred to comprising a collapsible container and a plurality of separate chambers 'for storing compressed air in different compartments under' the same pressures softhatthe compressed air from one chamber may beused to effecta partial inflation of y'5 the coilapsible container to lessen its weight due to its buoyancy while itv is being` attached to the vessel, after' which'the'compressed air from another chamber may be employed to effect a further' inflation of `the container when every- 10 thing is in readiness vfor bringing about the elevation ofthe sunken vessel.` A 'further object is to provide a lifting buoycomprising a collapsible containerand Ya drum attached thereto for stor- H ing fluid' under pressure, in combinationwith 15 improved means for causing the 'fluid in the drumto inflate the collapsible container when desired.` Another ob'ject is to provide a lifting buoy'coniprising a collapsible container adapted to be inflated after being attached to a'sunken 20 vessel in lcombinati-on with meansv forautomaticallyrelieving the pressure in the container as the lifting buoyv andthe vessel move upwardly through the water. Other objects relateto various 'features of construction' andI arrangement 25 of' the apparatus 'which will appear more fully hereinafter.

The nature of 'the'invent-ion will vbe understood from the following specification taken with the accompanying drawings in Y"which one em- 30 bodimentpof the invention is illustrated: In the drawings-.. I 1. v 'f. Y

Figure 1 shows a somewhat diagrammatic vertical sectionth'rough a body of water illustrating a sunken-vessel resting on the-bottom and 35 having attached thereto a-plurality of lifting buoys embodying the present invention and adapted to be controlled `fromal boat or scow whichislocated at the surface;

Fig. 2 shows a side elevation of one form of ,0 the limproved lifting buoy, illustrating by dotted lines the position'vof the wall of theI collapsible container after it has been deflated and bent downwardly about the metal drum in whichthe compressed airor other fluid is stored; n Fig. 3 is a detailed vertical section similar to that ofa portion o'fFig. showing the inlet valve of thecollapsible containerafter the valve disk or diaphragm has been puncturedto permit the compressedfluid in the drumy to pass into the collapsible container;`

Fig. ishows an `enlarged bottom planjview of the lifting buoy illustrated in Figs. Z-and 5; and

'Fig'.v5 shows an enlarged vertical section taken l 0n the irregular linea-5 of Fig. 4. 55

One method of use of the invention is shown in Fig. 1 where a plurality of the improved lifting buoys I0 are attached by straps II to hooks or other objects I2 fastened around the upper edge, along the sides, over the top, and distributed on the inside of the hull of a sunken vessel I3 which is to be lifted from the bottom I4 of a body of water I5. In this View, the collapsible containers I6 of the lifting buoys I0 are deflated and are folded downwardly about the outer surfaces of the metal drums I'I which are adapted to be illled with compressed air or other fluid before being put in place on the sunken vessel I3 by a diver. After all of the lifting buoys I0 have been attached to the vessel, the compressed fluid in the drums I I is adapted to be released simultaneously through valve mechanism which is controlled through hose connections leading from a common hose or conduit I8 which extends downwardly from a boat or scow 20 located at the surface of the water. In the arrangement illustrated, branch conduits I 8a lead from the conduit I 8 to a series of headers or casings I9 mounted on the vessel and hose connections |99- extend from these headers to the lifting buoys I0. The boat or scow 20 has an air compressor 2I mounted thereon or a tank containing a supply of compressed air or the like and the pipe or conduit I8 leads from this source of compressed uid supply to the branch conduits or hose connections I8 by which the valve mechanism of the various lifting buoys IU is controlled. It is thus possible to actuate the valve mechanism of all of the lifting buoys simultaneously by controlling means carried by the boat or scow 20 so that all of the collapsible containers I6 will be simultaneously inflated to bring about the elevation of the vessel I3 to the surface of the water due to the buoyant action of the lifting device I0.

As shown in Figs. 2, 4 and 5, the collapsible container I6 of each lifting buoy I0 is substantially spherical in form except on one side where it is attached to the metal drum I1. The collapsible container I 6 is formed preferably of rubber or of a composition of rubber and reinforcing fabric so that it is strong and durable while being of sullicient flexibility to permit it to be folded downwardly around the walls of the drum II as shown by the dotted line 22 in Fig. 2'. 'Ihe collapsible container or globe I6 is provided on one side with an annular flange I6 which surrounds and closely fits one end of the annular wall I'le of the metal drum. 'Ihis drum is provided at its upper end with an integral head IIb and a rib or shoulder IIc is attached to or formed on the annular wall I'Ia adjacent this head. The flange I 6a of the collapsible container ts the annular wall IIa just below the rib I1 and is secured in place by a strap 23 which extends around this flange and around the drum. The ends of this strap may be welded or otherwise secured together after it has been drawn taut around the flange I6a and this flange is provided along its lower edge with an annular outwardly projecting shoulder I6b which is adapted to engage the lower edge of the strap 23 to hold the collapsible container or globe securely in place. At its lower end, the drum I1 has a head I'Id which is formed integrally with the annular wall I'Ia or secured thereto by welding or the like. This head I'Id is united with a flange or rib IIe which extends diametrically across the lower end of the drum and which has a centrally located aperture therein adapted to be engaged by a bolt 24 which engages the arms IIa of one of the straps II by which the drum II is attached to the vessel I3. The arms IIB of this trap extend on opposite sides of the rib I'le and a nut 25 engages the threaded end of the bolt to secure it in place.

The drum I1 has an internal chlamber 26 adapted to contain the supply of compressed air or other fluid by which the collapsible container or globe i6 is to be inflated after the drum II has been attached to the vessel. This chamber is adapted to be lled with compressed fluid to the desired pressure through an inlet valve 21 which may be located in any wall of the drum, but which, in this embodiment, is shown as being mounted in the wall of an exhaust conduit 28 which communicates with the collapsible container I6 through the upper head I1b and which is constructed in the form of an elbow so that it opens outwardly through the cylindrical wall II of the drum. A boss 28EL is formed on the wall of this exhaust conduit 28 opposite its outlet and a valve plug 29 is threaded into an internally threaded recess formed in this boss with the valve stem 30 projecting into the inlet opening 3I which is formed through the boss. A coil spring mounted on the valve stem normally forces the cone-shaped valve 32 against its seat on the member 33 which is threaded into the plug 29, as in the usual construction of air valves. The plug 29 is adapted to be connected with a coupling on the end of a tube leading from an air compressor or source of compressed air from which a supply of compressed a'ir or the like may be forced into the chamber 26 of the drum. This is preferably done on shore or at some point removed from the place where the vessel is to be raised and when the drum has thus been filled, the lifting buoy I Il, of which it forms a part, may be taken to the place where it is to be used and then attached by a diver to a part of the vessel which is to be elevated.

When all of the lifting buoys IB have been. connected to the vessel I3, the compressed air or other fluid in the chamber 26 of the drums I1 of these devices is released so that all of the globe-like collapsible containers I6 are simultaneously inflated to the necessary extent to cause them to effect the elevation of the vessel to the surface by reason of the buoyant action of the water thereon, The means for releasing the compressed fluid in the chamber 26 of each device is shown patricularly in Fig. 5 where the upper head I'Ib of the drum is shown as being provided with an inwardly extending boss 35 havi ing a passage 36 leading therethrough to communicate with the interior of the collapsible container I6. This boss is provided with an enlarged internally threaded recess 35EL in which there is mounted a threaded plug 3l. The lower end of this plug forms a valve seat against which is mounted a circular valve disk or diaphragm 38 formed of comparatively thin metal, such as copper, having sufficient strength to withstand the pressure in the chamber 26 While at the same time being capable of being punctured when it is desired to permit the compressed fluid in this chamber to flow into the collapsible container I6. The valve disk or diaphragm 38 has a fiber washer 38@ on each side thereof to serve as packing and this valve disk and fiber washers are held in place by a tubular guide member or cap 39 which is internally threaded at its upper end to engage the lower threaded extremity of the plug 37. The lower portion of this cap member 39 has a smooth inner bore 39a which is closely fitted by the punch or plunger 4i! having a pointed end 40a which is adapted to puncture the valve disk or diaphragm 3S when the operator wishes to permit the compressed uid in the chamber 26 to ow into the collapsible container. In order to facilitate this flow of fluid after the diaphragm has been punctured, the cap member 39 is provided with radially extending passages 391 which communicate with the central bore 39L and Which,-when the plunger 40 is in its upper position, as shown in Fig. 3, communicate with the radial passages 4Gb in the plunger 40. This plunger is provided with an axial passage 40C communicating with the radial passages 4lb so that the compressed duid can flow through the connected passages into the chamber of the plug 3l" and thence into the passage 36 which leads to the interior of the collapsible container.

In order that the punch or plunger 49 may be actuated by a workman on the boat or scow 2i! at the surface of the water, iiuid pressure actuated means are provided for moving the plunger 4l! from the position shown in Fig. 5 to the position sho-wn in Fig. 3, this means being controlled by compressed air or the like supplied through the conduit I8 and the branch conduits lila, previously referred to. As shown in Fig. 5, this actuating mechanism comprises a tubular casing 42 which is mounted within the, drum H with its lower end opening through the head lid to which it is welded or otherwise integrally united. The casing 42 forms a chamber adapted to receive a removable cylinder 43 which is externally threaded at its upper end for detachable engagement with the internally threaded' aperture which is formed in the upper end wall 42a of the casing. This cylinder 43 is provided at its upper end with an integral end Wall 43a having a central aperture 43b therein which is closely tted and slidably engaged by the punch or plunger 4i). This end wall 43EL has an integral annular flange 43'3 projecting therefrom to form a packing chamber around the plunger 4G. This packing chamber is lled with packing'material 44 and a packing gland 45 surrounds the plunger 40 and ts in the upper end of this packing chamber so that when the packing nut 46 is threaded onto the externally threaded flange 43, the packing material 44 is compressed to form a fluid-tight joint about the relatively movable plunger 43.

The plunger 4G is adapted to be moved up- Awardly to puncture the valve disk 38 by a cylindrical piston 48 which is mounted to reciprocate in the cylinder 43. This piston is provided with annular grooves 48a in its outer wall and a disk 43", of leather or the like, is secured to the lower end thereof by a screw 49 in order to form a huid-tight connection with the wall of the cylinder. The piston is provided at its upper end with a recess 43C which is closely fitted by the lower extremity 4N of the plunger 40. This plunger has a collar 40e secured thereto to lit against the upper end of the piston 48 and a tubular rguide member or sleeve 5l) is provided with a bore of the guide member is spaced from the end wall 43a of the cylinder a distance corresponding to that through which the plunger 4!! is permitted to move when it is actuated by the piston 48, thus preventing the pointed end 40ab of the plunger from jmoving upwardly beyond the position shown in Fig. 3 where the passages 4Gb register with th-e passages 39h. This upward movementof the plunger 40 and the piston 43 is effected by compressed air or the like admitted to the lower end of the cylinder 43 beneath the piston. For this purpose, the lower end of the cylinder 43 is internally threaded and is engaged b-y a plug 53 having a passage 53a therethrough which is threadedly engaged by a nipple 54 to which one of the hose'connections itEL is connected. When compressed air or other iiuid is admitted throughl the hose connection 19a, under the control of the'operator on the boat or scow 2G, the piston 4B moves upwardly and causes the plunger 4@ to puncture the valve disk 3B thereby admitting compressed air or the like from the chamber 25 into the collapsible container I6.

In order to permit the escape of any fluid contained inthe cylinder 43, between the head 43a and the piston 48, when the piston moves upwardly, and also to Aequalize the pressures on opposite sides of the piston 48 before the hose 19a is connected to thelcylinder, a vent opening or port 55 is provided in the side of the cylinder, as shown in Fig. 5. When the piston 48 is .actuated by compressed air supplied through one of the hoses l9a, the wateror air in the upper part of the cylinder will flow out through this port 55 so that there will be no back pressure acting on vthe piston. Before the hose ma is connected to the plug 53 in the end of the cylinder, the lower end of the piston 48 is subjected to the pressure of the water at the depth .at which the lifting device is located, and if this pressure were not equalised it would force the plunger 4U upwardly and puncture the valve diaphragm `*before the operator is ready for that to occur, but the vent 55 permits the same water pressurej to be applied to the upper end of the piston A48 so that difculty is prevented. When thehose ma is connected, the compressed air supplied therethrough must have a pressure suflicient to overcome that of the water acting upon the upper end of the piston 48.

In order to replace the valve disk 38 for a succeeding use of the device after one of these valve disks hasbeen punctured, it is necessary toremove the -cylinder 43 and the parts carried thereby together with the plunger 4B and the cap member 39. To permit this to bedone, the lower end of the cylinder 43 is provided with a portion 43c of hexagonalcross section which is adapted to be engaged by a socketwrench inserted into the casing 42. The cylinder 43 may then be screwed out of its engagement with the end wall 42a of the casing and be thus removed bodily along with the plunger lill. Access may then be had to the cap member 39 which is similarly provided with an external surface Vof hexagonal cross section so that it may be engaged by a socket wrench to permit'it to be unscrewed. The cap member 39 preferably has a lighter engagement with the plug 3l than the engagement of this plug with the

boss

35,50 that upon unscrewing the cap member 39, the plug 3l will not be removed with it. After thev cap member 39 has been removed, new fiber washers 38' and a new valve disk 38 are put in place in the cap member Where they are heldA by friction while the cap member is being restored to the position shown in Fig. 5, which may be done before putting the cylinder 43A and the `plunger 40 back in place. It willbe understood that after compressed air has been applied through one of the hose connections I 9a to cause the plunger 40 to puncture the valve disk 3B, the piston 48 and the plunger 40 will be restored to the position shown in Fig. 5 by the action of the spring 5|.

After the plungers 40 of all of the lifting buoys I 0 have been actuated in the manner described above to puncture the valve disks 38, the collapsible containers I6 will be inflated by internal pressure, depending upon the pressure of the charge initially placed in the chambers 26 of the drums. The pressure of this initial charge in the drum and that of the collapsible container I6 when it is first inflated Will depend upon the depth at which the lifting device is to be used, the pressure being increased as the depth of the water increases. For example, if the collapsible container is four feet in diameter and is to be used at a depth of three hundred feet, it is desirable to use a drum I'I about thirteen inches in diameter and about four feet high, and under those circumstances there would be about three hundred and thirty cubic feet of air in the chamber 26 at a pressure of thirteen hundred pounds. When this pressure is released at a depth of three hundred feet, the collapsible container I6 would be inflated with a pressure of about one hundred thirty pounds per square inch.

For illustration of the method of calculating the sizes of the collapsible container and drum to be used under given conditions, let it be assumed that the lifting buoy is to be attached to the vessel at a depth of three hundred feet and that each lifting buoy is to have a buoyant force of two thousand pounds. To find the capacity of the collapsible container, this buoyant force is divided by the weight of a cubic foot of water (to be displaced) giving 32 cubic feet as the capacity, if the container is to be used at the surface. This corresponds roughly to the capacity of a globe having a diameter of four feet. Since water has a pressure of 0.434 pound per foot of depth, the water pressure to be overcome at a depth of three hundred feet by the pressure in the container is obtained by multiplying these figures (300 x 0.434) which gives 130.20 pounds per square inch. The pressure of the atmosphere under standard atmospheric conditions at sea level being 14.7 pounds per square inch, the number of atmospheres of pressure at a depth of three hundred feet is obtained by dividing 130.20 by 14.7 and adding one atmosphere, acting on the surface, giving a total of 9.8571 atmospheres. To nd the number of cubic feet of air required to give a pressure of 130.20 pounds per square inch at the depth mentioned, the figure 9.8571 is multiplied by 32 giving 315.427 cubic feet of air required in the collapsible container. If it be assumed that the drum I1 is to be thirteen inch-es in diameter and four feet high, which is a convenient size to use with a collapsible container I6 having a diameter of about four feet, the capacity of the drum would be 3.687 cubic feet. In order to ll the co1- lapsible container from this drum with air at a pressure of 130.20 pounds per square inch, the air in the drum would have to be compressed to an .amount determined by dividing the cubic feet required in the collapsible container by the capacity of the drum, subtracting one atmosphere from the result, and multiplying by the atmospheric pressure, 14.7 pounds per square inch, giving 1242.901 pounds per square inch as the pressure of the air in the chamber 26 of the drum. This calculation does not take account of the fact that the space within the drum I1 is partially occupied by the

members

28, 40, 42, 43, "Ill, and 1S, and the pressure in the drum should therefore be higher than the figure just calculated. In addition, it is desirable to use an excess of pressure in the collapsible container when it is first inflated so that it exerts a jarring action on the vessel tending to release it from the bed on which it rests. This is caused by having an excess amount of air compressed in the drum I1 so that it inflates the collapsible container with an excess of air which tends to open the automatic valve 60 because the pressure in the container I6 is then greater than the surrounding water pressure. For these reasons, the pressure should preferably be increased to sixteen hundred pounds per square inch in a drum of the size under consideration.

As the lifting devices rise to the surface with the vessel, it is necessary to release the pressure in the collapsible containers IB in order to prevent them from bursting as the water pressure is reduced. This is accomplished by providing an automatic valve 60 in the exhaust conduit 28, previously referred to, which opens through the upper head I'Ib of the drum, as shown in Fig. 5. Each valve comprises a frame member or spider 6I secured to the wall of the conduit 28 and having an annular valve seat 6 Ia engaged by a valve member 62 of rubber or the like having a curved upper surface to t closely against the valve seat. This valve member 62 is carried by a cup-shaped member 63 which is threaded onto the lower end of a valve stem 64 and which has its annular ange 63a of such height that it will engage the curved lower part of the member 6I to limit the compression of the valve member 62 when the valve is closed by the water pressure acting upon it. This valve stem slides in a guide SIb carried by the spider 6I and a coil spring 65 is mounted between the head of this valve stem and the end of 4the guide BIb so that the spring normally maintains the valve in a closed position against the pressure of the air or other fluid which is contained in the collapsible container I5. The pressure of the water on the outside of the drum acts on the outside of the cup-shaped member 63 toi assist in maintaining the valve in its closed position. As the lifting device rises to the surface, however, the water pressure on the outside of the valve will decrease sothat there will be a gradual opening of the valve and a gradually relieved pressure within the collapsible container.

The lifting device is also preferably provided with means for effecting a partial inflation of the collapsible container I6 in order to render the entire device somewhat buoyant during the period that it is being taken down by the diver and attached to the vessel. For this purpose, the drum is provided with an auxiliary casing 'I0 which is closed at its upper end and which has its open lower end united with the lower head I 'ld of the drum around an aperture therein. This auxiliary casing is preferably formed in two sections 'I0a and 70h, for convenience in manufacture, the upper section '10b being closed at its upper end by an end wall 10C, and the upper end of the lower section being closed by a transverse wall 10d. A chamber 'II is thus formed between the two end walls 'I0c and 70d for the storage of a comparatively limited quantity of compressed air or the like which is to be used to effect the partial iniiation of the collapsible container I6. The transverse wall 10d has a boss 'l2 carried on the upper side thereof and this boss 75 has formed therein a' valve-'chamber 'i3 'which Ycommunicates, Withy the'f'chamber li through ports 14. This valve chamberr'l has a passage 15 :leading upwardly therefrom tov 'communicate with a tube 16 Which is secured in the upper end of .tlie'zbos's H72 and which is Welded in an aperture formed in the upper end Wall lil of the auxiliary casing. This tube, which is preferably formed of metal having considerable ductility, extends through the chamber 2t and has its upper end secured in the upper end Wall lib of the drum so that it communicates with the chamber of the collapsible container l5. This tube 16 is of greater length than is necessary to extend from the boss 'l2 to the head lib and has a plurality of curves therein so that it may extend or contract longitudinally Without breaking in case there is relative movement of the ill and Hd of the drum, Which may occur, for eX- ample, When one of the lifting devices is dropped on the ground from a considerable height.

The transverse Wall 'Mld has an internally threaded aperture Which is detachably engaged by an externally threaded valve plug l'l having a central passage lla leading therethrough and communicating at its upper end with transverse passages l'lb which lead into the valve chamber 13. This valve plug ll has a cone-shaped upper end 'VIc which is: adapted to engage and close the lower end of the passage 'l5 when the valve plug is in its uppermost position. When in that position, the chamber l! is adapted to be charged with compressed air or the like through Van inlet valve 18 which is mounted in the lower end of the valve plug l1 to communicate with the passage lla. This valve is similar to the valve ill previously described and is normally closed so that it retains the charge of compressed air or the like in the chamber 'H after this chamber has been lled. When the Workman Wishes to permit the charge of compressed air in the chamber il to pass into the collapsible container lli, the valve plug 'H is unscrewed from the position shown in Fig. 5in order to cause the tapered end llc to move off of its seat at the end of the passage l5. This turning of the valve plug may be accomplished by applying a socket Wrench to the her;- agonal portion 'l'ld Which is formed on the outer end of the plug. Having thus unscrewed the valve plug, the collapsible container lli will be partially inflated so that the lifting device may be more readily carried about by the diver who puts it in place on the sunken vessel.

In order to provide a fluid-tight joint around the valve plug ll, the transverse Wall 'iisd is provided With an externally threaded annular flange 'ille which forms a packing chamber around the valve plug. A Washer i9 closes the upper end of this chamber Which is partially lled with packing material 8G. A packing gland Si is adapted to fit into this packing chamber and to be moved upwardly by a cap member or nut il?. which threadedly engages. the flange we, thereby compressing the packing material lill.

Although one form of the invention has been shown and described by Way of illustration, it Will be understood that it may be constructed in various other forms coming within the scope of the appended claims.

I claim: f

1. The combination in a lifting device for vessels, of a collapsible container adapted to be attached to a sunken vessel, means attached to and movable with said container for partially inating said container preliminary to attaching said device to said vessel, and additional means attached to 'and movable With said container for further. inflating said container after it has been connected With said vessel.

2'. .The combination in a lifting device adapted to be attached vto a sunken vessel, of a collapsible container, a drum attached to said container and having a chamber adapted to contain fluid under pressure, means including a valve disk for normally preventing the flow of said fluid from said chamber into said container, a detachable cap member for holding said valve disk in place, a plunger slidably engaging said cap member and adapted to puncture said disk, a casing extending into said drum and having an inner end. Wall provided with a threaded aperture, a cylinder threadedly engaging said aperture and having an end wall slidably engaged by said plunger, a. pistonmounted in said cylinder and operatively connected to said plunger, `,and means for admitting vcompressed fluid to said cylinder to operate said piston.

3. The combination in a lifting device adapted to be attached to a sunken vessel, of a collapsible container, a4 drum attached to said container and having a chamberv adapted to contain fluid under pressure, means including a valve disk for normally lpreventing the flow of said fluid from said chamber into said container, a detachable cap member for holding said valve disk in place, a plunger slidably'engaging said cap member and adapted to puncture said disk, a casing extending into said drum and having an inner end Wall provided With a threaded aperture, a cylinder threadedly engaging said 4aperture and having an end wall slidably engaged by said plunger, a

piston mounted inv said cylinder and operatively connected to said plunger, and means for limiting the movement of said piston.

4. The combination in a lifting device adapted to be attached to a sunken vessel, of a. collapsible container, a metal drum attached to said container and having a chamber for storing fluid under pressure, means for admitting said fluid to said container to inflate said container, an auxiliary casing extending into said drum and having an auxiliary chamber for containing fluid under pressure, said casing having an end Wall, a valve member threadedly engaging said Wall and having a passage therethrough, an inlet valve controlling said passage for 'permitting fluid under pressure to be passed into said chamber, and a conduit leading from said chamber to said container, the mouth of said conduit being normally closed by said valve member.

5. The combination in a lifting device adapted cylinder, said cylinder having a vent open to theV surrounding Water pressure on the side of said piston opposite that engaged by said compressed fluid. y Y

6. The combination in a lifting device adapted to be attached to a sunken vessel of a collapsible container adapted to be inflated, a drum attached to said container and adapted to have said container collapse about it, said drum having two compartments each adapted to contain a quantity of fluid under pressure, a valve for controlling the ow of fluid from one of said compartments to said container to eiect a partial inflation of said container, another valve for controlling the 110W of fluid from the other of said compartments to said container to effect a further inflation of said container, and means operated from the surface of the water for controlling said last named valve.

ANDREW BARNA.