US3820348A - Buoyancy regulating apparatus - Google Patents

Abstract

Buoyancy regulating apparatus is provided which permits a scuba diver wearing the apparatus to attain and maintain a desired buoyancy while descending or ascending in the water and regardless of his depth. The apparatus includes flexible bladders which are automatically inflated when their volume tends to decrease, and which are automatically deflated when their volume tends to increase, so that an equilibrium volume condition is maintained regardless of external water pressure.

Description

United States Patent [191 Fast [11] I 3,820,348 1 June 28,1974

[ 1 BUOYANCY REGULATING APPARATUS [76] Inventor: Gregory M. Fast, 9951 Grosalia Way, La Mesa, Calif. 92041 221 Filed: July 23, 1973 21 Appl. No.: 381,637

[52] US. Cl. 61/70, 9/316, 114/16 E [51] Int. Cl. B63c ll/02 [58] Field of Search 9/314, 316, 319, 342; 61/69 R, 69 A, 70; 114/16 E; 128/142,

[56] References Cited UNITED STATES PATENTS 3,487,647 1/1970 Brecht 61/69 R 3,520,263 7/1970 Berry et a1. 114/16 E 3,643,449 2/1972 Murphy.....I 61/69 R Primary Examiner-Mervin Stein Assistant ExaminerDavid H. Corbin Attorney, Agent, or Firm-Jessup & Beecher 5 7] ABSTRACT Buoyancy regulating apparatus is provided which permits a scuba diver wearing the apparatus to attain and maintain a desired buoyancy while descending or ascending in the water and regardless of his depth. The apparatus includes flexible bladders which are automatically inflated when their volume tends to decrease, and which are automatically deflated when their volume tends to increase, so that an equilibrium volume condition is maintained regardless of external water pressure.

8 Clains, 4 Drawing Figures FATENTEU JUN 2 8 I974 SHEET 2 0F 3 l BUOYANCY REGULATING APPARATUS BACKGROUND OF THE INVENTION It is usual for scuba divers to wear a wet suit composed of rubber or rubber-like material. However, normally the internal cell structure of the wet suit material entraps a relatively large quantity of air, and this reduces the normal density of the suit and renders it relatively buoyant. For that reason, at the initial stages of his descent, the diver finds it difflcult to move downwardly in the water. To solve this problem, it is usual in the prior art for the diver to wear a weight belt whose weight in water substantially equals the buoyancy of the diver. Usually, the effective weight of, the weight belt is selected to be a little greater than the buoyancy of the diver, so that the diver can descend freely and effortlessly into the depths of the water.

However, as the diver descends, the external water pressure increases, and this causes his wet suit to compress and lose its buoyancy. When that occurs, the effectiveness of the weight belt becomes excessive, and the diver finds himself pulled at a relatively high rate downwardly towards the bottom. To prevent this from occurring, it is usual in the prior artto provide the diver with an inflatable vest, which may be inflated from his pressurized air tank, by separate pressure cylinders, or

by any other appropriate means. The inflation of thevestrestores the desired buoyancy of the diver as he moves down into the depths of the water. On ascent, the vest is deflated by the diver, as the wet suit itself resumes its previous buoyant condition.

The prior art approach to the buoyancy problem, as described above, is not entirely satisfactory. This is because it is necessary for the diver to make continuous adjustments in order for his buoyancy in anyway to approach a constant state, during his descent or ascent. This is because amont other things, the inflatable vest, itself, becomes compressed as the diver descends into the water. The apparatus of the present invention-is constructed to provide a desired buoyancy for the diver on an automatic basis, and it relieves the diver of any need to make any manual adjustments in order to maintain a desired buoyancy, after he has made a preliminary setting to the apparatus.

Briefly stated, in the embodiment of the invention to be described, a manual control is provided by which the diver can adjust his buoyancy to a desired set point. Then, as the water pressure changes during the descent or ascent of the diver, the equipment of the invention causes the set point to be automatically changed so that an essentially constant buoyancy condition is maintained for all water depths, and this is achieved without the requirement for any further manual adjustments on the part of the diver. The automatic buoyancy control apparatus of the invention not only controls buoyancy as a function of water pressure, but also introduces an additional buoyancy adjustment to compensate for changes in density in the wet suit itself for different water pressures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective representation of the buoyancy control apparatus of the invention, in accordance with one embodiment of the invention;

FIG. 2 is a schematic representation of one embodiment of the invention, and shows the various components which cooperate with one another to achieve the desired purpose of the invention;

FIG. 3 is a side elevation of a control valve which is included in the assembly of FIG. 2, taken essentially along theline 3--3 of FIG. 2; and

FIG. 4 is a section of the valve of FIG. 3, taken along the line 4-4 of FIG. 3.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The apparatus of the invention in the embodiment of FIG. 1 is carried as a pack on the backof the diver in conjunction with theusual scuba tank 10. Thetank 10 contains compressed air which is used by the normal scuba diving apparatus. The internal mechanism of the apparatus of the invention to be described, is enclosed within a housing having a generally rectangular configuration, as shown in FIG. 1. The housing is made up of twosections 12 and 14, which are fitted together as shown in FIG. 1 to encompass thescuba tank 10. Thesections 12 and 14 are normally held together butsection 12 may be released by means of arelease button 16. When therelease button 16 is depressed, thesection 12 may be removed to reveal the inner components of the apparatus for servicing and replacement purposes.

The housing of FIG. 1 and the internal apparatus are worn on the back of the diver by means of a usual webbing suspension system comprising, for example,shoulder straps 18, a waist strap 20, and acrotch strap 22. A pair ofusual weights 24 are carried on the sides of the housing, and may be released if desired, by means of arip cord 26. The rip cord has aring 28 mounted on one of theshoulder straps 18. A setpoint hand wheel 30 for the apparatus of the invention is also provided, and it is conveniently mounted on theother shoulder strap 18. Theweights 24 are usually in the form of lead slugs mounted on the left and right sides of the housing.

The apparatus of the invention, as shown in FIG. 2 includes afirst air bladder 50 and asecond air bladder 52, each of which is sandwiched between two plates P1, P3 and P2, P4, respectively. The air bladder'50, for example, is sandwiched between the pair of plates P1 and P3, and theair bladder 52 is sandwiched between the pair of plates P2 and P4. In each case, the inner plates P1 and P2 are fixed, and the outer plates P3 and P4 are transversely movable. The outer plates tend to be displaced laterally in and out as the external water pressure changes. The plates P2, P4 and P1, P3 are hinged together by hinged end plates, as shown.

Acontrol valve 54 is mounted in the housing of the system, and this valve is operated, in a manner to be described, by means of a spring loadedcontrol yoke 56. Thecontrol yoke 56 has an intermediate position in which thecontrol valve 54 is closed. Then, if the control yoke is pulled downwardly, the yoke opens a first section in thecontrol valve 54 to release air pressure from theair bladders 50 and 52. When the control yoke is permitted to move upwardly, however, a second section of the control valve opens to introduce pressure from thescuba tank 10 into the interiors of theair bladders 50 and 52. Thecontrol valve 54 is coupled to theair bladders 50 and 52 throughflexible hoses 60 and 62, which extend throughrespective fittings 64 and 66 into the interiors of the bladders; and the control valve is coupled to the valve of thetank 10 through aflexible hose 68.

Thecontrol yoke 56 is moved relative to the body of the control valve by means of acable 70 which, as shown, is affixed to one end to the bottom of thecontrol yoke 56, and which extends around boththe air bladders by means of a series ofpulleys 72. The other end of the control cable extends through abracket 76 mounted on the plate P1, and through a tubular conduit 78 to the upper end of the apparatus. The end of the control cable is then looped around arotatable drum 80 which is controlled by the setpoint hand wheel 30 of FIG. 1.

- Two of the pulleys, designated 72a, are mounted on a plate P which, in turn, engages apad 86 composed of wet suit material. Thepad 86 is sandwiched between the plate P5 and the stationary plate P1. This pad provides a compensation for the changes in density of the wet suit material, since it also compresses or expands as water'pressure increases or decreases, introducing a compensation to the control of thebladders 50 and 52.

In the operation of the equipment, the diver first sets thehand wheel 30 to establish a predetermined buoyancy condition to the apparatus. Then, as the diverdescends into the water, the apparatus functions automatically to maintain the preset buoyancy condition- Specifically, and as noted above, as the ambient water pressure surrounding the equipment increases as the diver descends into the water, the water pressure compresses the air in thebladders 50 and 52, so that there is a tendency for the outer plates P4 and P3 to slacken thecontrol cable 70, and cause the cable to release its tension on thecontrol yoke 56. When that occurs, the spring bias within the control yoke moves it slightly upwardly in FIG. 1, causing more air pressure from the bank *to be introduced into the air bladders, so that their original volume may be maintained.

On the other hand, any decrease in water pressure produces a tendency for thebladders 50 and 52 to expand and cause plates P3 and P4 to move outwardly. This tendency causes thecontrol cable 70 to exert a tension on thecontrol yoke 56 moving it downwardly, so as to release air pressure from the air bladders and maintain their original volume. At the same time, the pad ofwet suit material 86 monitors the actual density of the divers wet suit, so that compensations are introduced into the control of the system to take care of changes in density and buoyancy of the divers wet suit.

Thecontrol valve 54 may be constructed as shown in FIGS. 3 and 4. As shown in'FIG. 3, for example, thecontrol yoke 56 completely surrounds thevalve 54. The valve has a spring loaded control button 100 protruding from its upper end, and theyoke 56 is secured to the control button by means of ascrew 102. Aspring 104 biases the yoke upwardly against the normal tension of thecontrol cable 70.

As shown in FIG. 4, thevalve 54 includes avalve body 106 which defines aninner chamber 108. The control button 100 is movable in a vertical passage which extends axially from thechamber 108 through the upper end of thevalve body 106. This passage has an enlarged lower section, and a piston 110 is movable in the lower section. The piston 110 is sealed to the walls of the lower section of the passage by means of an O-ring 112. A second piston 114 is movable in the passage above the piston 110, the piston 114 being sealed to the wall of the passage by an O-ring'l 16. Aspring 118 is interposed betweenthe control button and the piston 114, and a second spring 120 is interposed between the piston 114 and the piston 110.

The piston has a central passage, and the spring is disposed down into the central passage. A first intake port is provided which receives thehose 68 from thetank 10. This port communicates with the aforesaid passage, and the introduction of pressurized air from thetank 10 into theinternal chamber 108 is normally interrupted by the piston 114 which seats against the piston 110. However, when the piston 114 is biased upwardly away from the piston ll0'by the spring 120, the pressurized air is free to flow through the piston 110 into thechamber 108, and into the bladders 20 and 21 throughports 132 and 134. Thehoses 60 and 62 are respectively coupled to theports 132 and 134 through an appropriate fitting 63 shown in FIG. 2.

An exhaust valve is provided at the bottom of the chamber .108, and the exhaust valve is normally biased into a closed. position by means of aspring 142. The control button 100 is coupled to the exhaust valve by means of apush rod 144. When thepush valve 140 is moved away from its seat by thepush rod 144, the'pressurized air in thechamber 108 is free to flow throughexhaust ports 150. Anadjustment screw 152 is provided for thepush rod 144. The control button 100 itself is sealed to thebody 106 by means of an O-ring 160.

Thevalve 54 of FIG. 4 is shown in its normal position, in which there is no flow of pressurized air through the valve. Now, should the control button 100 be permitted to move upwardly in FIG. 4, due to the fact that the .efiective volume of thebladders 50 and 52 has decreased, thespring pressure 118 is relaxed, and the spring 120 overcomes the former spring pressure to bias the piston 1 14 away from the top of thepiston l 10. This opens an inlet passage for the air from theport 130 into thechamber 108, so that pressurized air from thescuba tank 10 may flow through the ports l32and 134 to theair bladders 50 and 52, to restore their original volume.

On the other hand, should the volume of theair bladders 50 and 52 increase, the resulting movement of the plates P3 and P4 causes the control cable to pull thecontrol yoke 56 downwardly. This causes thepush rod 144 to open theexhaust valve 140, so that air pressure in the bladders may be relieved through theports 132 and 134, and downwardly through theexhaust valve 140. Similar action is caused under the control of thewet suit pad 86, for the additional compensation described above. Thepad 86 is removable, so that it may be replaced by other pads matching in each instance the actual wet suit worn by the diver.

Because of the pressure gradient of the water, it is desirable to raise the internal pressure of thebladders 50 and 52 to a point slightly above the ambient pressure, so as to compensate for the otherwise crushing effect of the water on the bottom of the bladders when the system is in a vertical position. This is achieved, for example, by means of a pair of resilient straps 103 (FIG. 2) extending around the apparatus and embracing the outer plates P3 and P4. A spring 104 (FIG. 3) is positioned between the control valve and theyoke 56 to provide a small bias on the cable and control valve so that the desired pressure differential between the air bladders and ambient pressure may be maintained at all times.

The invention provides, therefore, a relatively simple and inexpensive apparatus which may be worn by a scuba diver, or the like, and which permits the scuba diver to set a desired level of buoyancy, which level is automatically maintained by the apparatus as the diver moves downwardly or upwardly in the water. The apparatus also includes a simple compensation means for changes in density of the divers wet suit for different depths in the water.

ltwill be appreciated that while a particular embodiment of the invention has been shown and described, modifications may be made. It is intended in the claims to cover the modifications which fall withinthe spirit and scope of the invention.

What is claimed is:

1. Buoyancy regulating apparatus for scuba divers, and the like, comprising:

a housing;

suspension means attached to said housing for supporting the housing on a diver;

a source of compressed fluid mounted on said housflexible bladder means mounted on said housing;

valve means;

means pneumatically'coupling said valve means to said source of compressed fluid and to the interior of said bladder means to introduce compressed fluid from said source to said bladder means for a first position of said valve means and to exhaust fluid from said bladder means for a second position of said valve means; and

control means mechanically intercoupling said bladder means to said valve to move said valve to said first position for decreases in the volume of said bladder means, and to move said valve to said second position for increases in the volume of said bladder means.

2. The buoyancy regulating apparatus defined in claim 1, and which includes a rigid member engaging said bladder means and movable upon changes in the volume thereof, and a cable interconnecting said rigid member with said valve means.

3. The buoyancy regulating apparatus defined in claim 1, in which said control means includes a cable interconnecting said bladder means to said valve means, and a manual control coupled to said cable for establishing a particular tension in said cable to set a desired buoyancy level to be maintained by the apparatus.

4. The buoyancy regulating apparatus defined inclaim 3, in which said control means includes compensating means coupled to said cable for introducing a further control effect into the apparatus as a function of the density of the wet suit worn by the diver.

5. The buoyancy regulating apparatus defined inclaim 3, in which said compensating means comprises a pad of wet suit material similar to the material of the suit worn by the diver.

6. Buoyancy regulating apparatus defined in claim 1 in which said control means includes first and second rigid plate members and a bladder sandwiched therebetween, one of said plate members being affixed to said housing and the other of said plate members being movable laterally with respect to said first plate member for changes in volume of the bladder.

7. Buoyancy regulating apparatus defined in claim 6, in which said valve includes a spring'loaded yoke, and in which said control means includes a cable interconnecting said movable plate with said yoke.

8. Buoyancy regulating apparatus defined in claim 7, in which one end of said cable is attached to said yoke; and in which said control means includes a manually rotatable set point control, and in which the other end of said cable is wound about said rotatable control.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 2 820 a 348 Dated June 28 a 1974 Gregory M. East Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The inventor's name should read Gregory M. East Signed and sealed this 12th day of November 1974.

. QSEAL) Attest;

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer I Commissioner of Patents =OFTM FO-DSO (10-6 I USCOMM-DC scan-ps9 U.S. GOVERNMENT PRINYING OFFICE: a 9. 93 o

Claims (8)

1. Buoyancy regulating apparatus for scuba divers, and the like, comprising: a housing; suspension means attached to said housing for supporting the housing on a diver; a source of compressed fluid mounted on said housing; flexible bladder means mounted on said housing; valve means; means pneumatically coupling said valve means to said source of compressed fluid and to the interior of said bladder means to introduce compressed fluid from said source to said bladder means for a first position of said valve means and to exhaust fluid from said bladder means for a second Position of said valve means; and control means mechanically intercoupling said bladder means to said valve to move said valve to said first position for decreases in the volume of said bladder means, and to move said valve to said second position for increases in the volume of said bladder means.

2. The buoyancy regulating apparatus defined in claim 1, and which includes a rigid member engaging said bladder means and movable upon changes in the volume thereof, and a cable interconnecting said rigid member with said valve means.

3. The buoyancy regulating apparatus defined in claim 1, in which said control means includes a cable interconnecting said bladder means to said valve means, and a manual control coupled to said cable for establishing a particular tension in said cable to set a desired buoyancy level to be maintained by the apparatus.

4. The buoyancy regulating apparatus defined in claim 3, in which said control means includes compensating means coupled to said cable for introducing a further control effect into the apparatus as a function of the density of the wet suit worn by the diver.

5. The buoyancy regulating apparatus defined in claim 3, in which said compensating means comprises a pad of wet suit material similar to the material of the suit worn by the diver.

6. Buoyancy regulating apparatus defined in claim 1, in which said control means includes first and second rigid plate members and a bladder sandwiched therebetween, one of said plate members being affixed to said housing and the other of said plate members being movable laterally with respect to said first plate member for changes in volume of the bladder.

7. Buoyancy regulating apparatus defined in claim 6, in which said valve includes a spring loaded yoke, and in which said control means includes a cable interconnecting said movable plate with said yoke.

8. Buoyancy regulating apparatus defined in claim 7, in which one end of said cable is attached to said yoke; and in which said control means includes a manually rotatable set point control, and in which the other end of said cable is wound about said rotatable control.

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