EP0721882A1

EP0721882A1 - Scuba diving apparatus with rate-of-ascent control

Info

Publication number: EP0721882A1
Application number: EP95100303A
Authority: EP
Inventors: Daniel Biran
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-01-11
Filing date: 1995-01-11
Publication date: 1996-07-17

Abstract

Scuba diving apparatus includes a buoyancy compensator attachable to a diver, and a rate-of-ascent control device for sensing the rate-of-ascent of the diver and for automatically decreasing the buoyancy of the buoyancy compensator when the rate-of-ascent exceeds a predetermined value.

Description

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to scuba diving apparatus, and particularly to such apparatus including a rate-of-ascent control to prevent the diver from ascending at an excessively high rate which may be harmful to the diver.
Scuba diving apparatus generally includes a buoyancy compensator attachable to the diver to control the buoyancy of the diver and thereby the depth at which the diver may operate. One form of buoyancy compensator includes an inflatable device, such as an inflatable pillow to be attached to the diver or an inflatable jacket to be worn bdy the diver, and a pressurized gas tank attachable to the diver for inflating the buoyancy compensator. In the conventional apparatus, the inflation or deflation of the buoyancy compensator is manually controlled by the diver. However, in such apparatus, there is a danger that the diver may unwittingly ascend at an unduly high rate such as may cause the formation of nitrogen bubbles in the blood, a disorder called "bends", which can be extremely painful and even fatal.

OBJECTS AND BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide scuba diving apparatus automatically preventing the ascent of the diver from exceeding a predetermined rate which may be harmful to the diver.
According to the present invention, there is provided scuba diving apparatus comprising: a buoyancy compensator attachable to a diver; and a rate-of-ascent control device for sensing the rate-of-ascent of the diver, and for automatically decreasing the buoyancy of the buoyancy compensator when the rate-of-ascent exceeds a predetermined value.
According to further features in the preferred embodiments of the invention described below, the buoyancy compensator is an inflatable device attachable to the diver so as to be submerged in, and therefore subject to the pressure of, the ambient water. The apparatus includes a pressurized gas tank also attachable to the diver for inflating the inflatable device. The rate-of-ascent control device automatically vents the interior of the inflatable device to the ambient water when the rate-of-ascent exceeds a predetermined value.
According to still further features in the described preferred embodiments, the rate-of-ascent control device includes a housing attached to the inflatable device and having an inlet communicating with the interior of the inflatable device, an outlet communicating with the exterior of the inflatable device, a control passageway between the inlet and outlet, and a displaceable member normally closing the control passageway but effective to open the control passageway, and thereby to connect the interior of the inflatable device to the ambient water, when the rate-of-ascent of the diver exceeds a predetermined value. For this purpose, the housing further includes a control chamber having a slow-acting vent causing the pressure therein to gradually follow the ambient water pressure. The displaceable member is normally biassed to close the control passageway, but is effective to open the control passageway when the pressure in the control chamber is larger than that of the ambient pressure by a predetermined amount. The arrangement is such that when the ascent of the diver exceeds a predetermined rate, the lag in pressure changes between the control chamber pressure and the ambient water pressure produces a differential pressure which is sufficiently large to move the displaceable member to open the control passageway and thereby to discharge air from the inflatable device, thereby slowing or stopping the ascent.
In the described preferred embodiments, the displaceable member is a membrane, and the inflatable device is a buoyancy jacket to be worn by the diver.
It will thus be seen that apparatus constructed in accordance with the foregoing features automatically prevents the diver from ascending at a rate exceeding a predetermined value which might be harmful to the diver. Thus, as soon as this predetermined rate-of-ascent is sensed, the interior of the inflatable buoyancy compensator is automatically vented to the ambient water, thereby immediately slowing or stopping the ascent.
Further features and advantages of the invention will be apparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:

Fig. 1 illustrates one form of scuba diving apparatus constructed in accordance with the present invention; and
Figs. 2, 3 and 4 illustrate three forms of rate-of-ascent control devices that may be used in the apparatus of Fig. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS

The Overall Construction

The scuba diving apparatus illustrated in Fig. 1 comprises a buoyancy compensator in the form of an inflatable buoyancy jacket BJ which is to be worn by the diver or otherwise attached to the diver. It includes inflatable chambers to adjust the buoyancy of the diver, and thereby to permit the diver to operate at different depths. Attached to the buoyancy jacket BJ is a pressurized air tank PT which supplies air to inflate the buoyancy jacket BJ via a pressure regulator PR and conduits 2 and 3. The latter conduits include a depth control device DC provided with manual controls 4, 5, and an inflator tube IT, permitting the diver to control the degree of inflation of the buoyancy jacket BJ manually. For example, manual control 4 may be a button which is manually depressed by the diver in order to introduce air into the inflatable buoyancy jacket BJ, and manual control 5 may be a second button depressed by the diver in order to discharge air from the buoyancy jacket BJ, or to inflate it by blowing through inflator tube IT.
The pressure tank PT also supplies breathing air to the diver via a conduit 6, demand regulator DR, and mouthpiece MP. A pressure gauge PG, connected to the pressure tank PT via the pressure regulator PR and conduit 7, enables the diver to observe the pressure state of the pressure tank PT. Pressure gauge PG also carries a depth gauge DG enabling the diver to observe the depth of the diver.
Scuba diving apparatus insofar as described above is well known and therefore further details of the structure and operation are not set forth herein.
According to the present invention, the buoyancy compensator, in this case the inflatable buoyancy jacket BJ, is provided with a rate-of-ascent control device ROA which is effective to sense the rate-of-ascent of the diver and automatically to decrease or terminate the ascent when it exceeds a predetermined rate which may be harmful to the diver. This is done by automatically venting the interior of the buoyancy jacket BJ to the ambient water in order to discharge a quantity of air from the jacket to thereby reduce the buoyancy of the diver.
Figs. 2, 3 and 4 illustrate the construction of three rate-of-ascent control devices which may be used for the device ROA in Fig. 1.

The ROA Control Device in Fig. 2

The rate-of-ascent control device ROA shown in Fig. 2 includes a rigid housing 10 having an inner section 10a located within the buoyancy jacket BJ, and an outer section 10b projecting outwardly of the buoyancy jacket. The inner housing section 10a includes a plurality of inlets 12 communicating with the interior of the buoyancy jacket BJ. The outer housing section 10b includes a plurality of outlets 13 communicating with the ambient water in which the diver is submerged. A control passageway 14 connects the inlets 12 with the outlets 13.
A displaceable valve member 15 is located within the control passageway 14 and is movable from a closed position (illustrated in Fig. 2) blocking the communication between inlets 12 and outlets 13, to an open position establishing communication between the inlets and outlets. Valve member 15 is engaged by one end of a stem 16 secured at its opposite end to the center of a membrane 17. The outer periphery of membrane 17 is secured to housing section 10a by means of a washer 18 fixed within housing section 10a.
The external housing section 10b includes a partition member 19 attached to the open end of housing section 10a, and a cap 20 secured to the open end of partition member 19. Partition member 19 defines with membrane 17 an inlet chamber 21 communicating with the inlet openings 12. Partition member 19 also defines an outlet chamber 22 with cap 20 communicating with the outlet openings 13, and a valve seat 23 engageable by valve member 15.
The outlet chamber 22 includes a coiled spring 24 between valve member 15 and the inner surface of cap 20. Spring 24 urges the valve member to its closed position seated on valve seat 23. Valve member 15 may be manually moved to an open position by a cord 25 passing through an opening 26 in cap 20. The inner end of cord 25 is secured to an eye 27 carried by valve member 15, and the outer end of the cord carries a knob 28 graspable by the diver to manually open the valve by pulling on the cord.
Housing section 10a is formed with a flow restrictor orifice 30 serving as a slow-acting vent between the interior of housing section 10a and the interior of the buoyancy jacket BJ. The portion of housing section 10a between membrane 17 and vent 30 acts as a pressure control air chamber. Vent 30 is slow-acting such that under static conditions, or gradually changing conditions, the pressure (P₁) within control chamber 31 of housing section 10a is substantially the same as the pressure (P₂) within the buoyancy jacket BJ; however, under rapidly-changing pressure conditions, occurring during the descent or ascent of the diver wearing the buoyancy jacket BJ, the change in pressure P₁ within control chamber 31 lags the change in pressure P₂ within the buoyancy jacket BJ. Thus, during a rapid descent of the diver, pressure P₂ within the buoyancy jacket BJ will be greater than pressure P₁ within control chamber 31; whereas during a rapid ascent, the pressure P₁ within the control chamber 31 will be greater than the pressure P₂ within the buoyancy jacket.
The apparatus illustrated in Fig. 2 operates as follows: The diver may control ascent and descent by manually depressing buttons 4 and 5 of the depth control device DC. Thus, depressing button 5 discharges some air from the buoyancy jacket BJ or permits the diver to blow air into the buoyancy jacket via the inflator tube IT; whereas depressing button 4 introduces air from the pressurized container PT into the buoyancy jacket BJ.
When the diver remains at substantially the same depth, pressure P₁ within control chamber 31 remains substantially the same as pressure P₂ within the buoyancy jacket BJ, by virtue of the slow-acting vent 30 in housing section 10a which causes pressure P₁ to slowly follow pressure P₂. In such case, the membrane is maintained by spring 24 in the valve-closed position illustrated in Fig. 2. In this condition, valve member 15 is seated on valve seat 23 thus blocks communication between the inlets 12 and the outlets 13.
When the diver is descending, pressure P₂ increases faster than pressure P₁, So that pressure P₂ becomes greater than pressure P₁. During this condition, valve member 15 remains in the illustrated valve-closed condition by spring 24 and the greater P₂ pressure.
However, when the diver is ascending, pressure P₂ decreases faster than pressure P₁ at a rate controlled by the slow-acting vent 30. When pressure P₂ becomes sufficiently smaller than pressure P₁ to overcome the action of spring 24, pressure P₁ will displace membrane 17 (upwardly in Fig. 2), to move the valve member 15 off valve seat 23, to thereby open the communication between the inlets 12 and the outlets 13. As a result, a quantity of air within the buoyancy jacket BJ will be discharged to the ambient water in which the diver is submerged. This decreases the buoyancy of the jacket, and thereby interrupts or slows down the ascent of the diver.
When the pressure P₂ again substantially equals pressure P₁, or at least is not less than it by the force of spring 24, valve member 15 will be returned by the displacement of membrane 17 back to its original, closed condition, seated against valve seat 23, to thereby terminate the discharge of air from the interior of the buoyancy jacket BJ via inlets 12 and outlets 13.
The diver may also interrupt or slow down the ascent by pulling cord 25; this manually opens valve member 15 and causes the discharge of air from the buoyancy jacket BJ via inlets 12 and outlets 13.

The ROA Control Device in Fig. 3

The rate-of-ascent control device illustrated in Fig. 3 is of a similar construction as that of Fig. 2, except that the device is not actually built into the buoyancy jacket BJ, as in Figs. 1 and 2, but rather is externally of, and pneumatically coupled to, the buoyancy jacket. Thus, in the control device illustrated in Fig. 3, the complete housing, therein designated 110, is externally of the buoyancy jacket BJ. The housing, however, includes inlets 112 connected to the interior of the buoyancy jacket, and outlet openings 113 through which air from the buoyancy jacket is discharged to the ambient water when the valve member 115 is opened.
The control device illustrated in Fig. 3 further includes a stem 116 engageable at its upper end with valve member 115, and secured at its lower end to a membrane 117 dividing the interior of housing 110 into an inlet chamber 121 and a pressure control air chamber 131. As in Fig. 2, the valve member 115 is urged to its closed position by a spring 124 between it and cap 120 attached to partition member 119. The pressure (P₁) of control chamber 131 is caused to follow the pressure (P₂) of inlet chamber 121 (equal to that of the ambient water) by means of a slow-acting vent 130 formed in the stem 116. Thus, vent 130 includes a transversely-extending orifice 130a communicating with inlet chamber 121, and an axially-extending orifice 130b communicating with the control chamber 131; one or both of these orifices are of small cross-sectional area.
It will thus be seen that the control device illustrated in Fig. 3 is otherwise constructed and operates in substantially the same manner as described above with respect to the control device of Figs. 1 and 2.

The ROA Control Device in Fig. 4

The control device illustrated in Fig. 4 includes a pressure control water chamber 231 located externally of the buoyancy jacket and having a gas-filled expansible member 232 which changes its volume inversely with the chamber water pressure (P₂). In this case, the slow-acting vent 230 is in the form of a flow-restrictor unit, such as widely used in drip irrigation, which vents the interior of the control chamber 231 to the outside ambient water via a filter 240, so that the pressure (P₂) within chamber 231 gradually follows the ambient water pressure (P₁).
A large number of different types of flow-restrictor units are known in drip irrigation. They generally reduce flow by a labyrinth, orifice, or another form of flow-restrictor passageway, some units having automatic flow regulation. They are generally available according to different flow rates, e.g., 1.5 liters/hour, 2.0 liters/hour, etc. Some types include a connector, such as shown at 241, permitting the unit to be quickly attached and detached, and also permitting it to be replaced by another flow rate unit according to the particular application.
The control device of Fig. 4 is otherwise generally constructed similar to the device of Fig. 3. Thus, it includes a housing 210 defining the external pressure control chamber 231 and having inlets 212 connected to the `buoyancy jacket and outlets 213 through which air from the buoyancy jacket is discharged to the ambient water when the valve member 215 is opened. Valve member 215 is carried at one end of a stem 216. The opposite end of the stem is secured to a membrane 217 dividing the interior of housing 210 into an inlet chamber 221, and the previously-mentioned control chamber 231. Valve member 215 is urged to its closed position by a spring 224 between it and a cap 220 formed with the outlet openings 213 through which air from the buoyancy jacket is discharged to the ambient water when the valve member 215 is opened.
Thus, during a slow ascent, the water pressure in chamber 231 decreases slowly so that the gas-filled member 232 within control chamber 231 expands slowly, permitting the flow-restrictor unit 230 to accommodate the slow outflow of water from chamber 231 to the ambient water. However, when the ascent is rapid, the water pressure in chamber 231 decreases more rapidly so that the gas-filled member 232 expands rapidly such that the flow-restrictor unit 230 is not able to accommodate the outflow of water, whereby the pressure within chamber 231 displaces membrane 217 to open valve 215 and thereby to expel air outwardly through the outlet openings 213.
While the invention has been described with respect to three preferred embodiments, it will be appreciated that may other variations may be made. For example, the cap (20, 120, 220) could be threaded to the housing to enable the force of the spring (24, 124, 224) to be adjusted, and thereby to enable presetting the operating point of the rate-of-ascent control device ROA. Also, the rate-of-ascent control device ROA could be at another place in the buoyancy jacket, or on the tube 3 connected to the buoyancy jacket. In addition, the buoyancy compensator could be of another type, such as an inflatable pillow or mattress attachable to the diver, rather than a buoyancy jacket worn by the diver. Further, valve member (15, 115, 215) may be controlled by another form of displaceable member, such as a piston rather than a membrane. In addition to the slow-acting vent, the housing could be provided with a one-way valve which quickly equalizes the pressure during descent.
Many other variations, modifications and applications of the invention will be apparent.

Claims

Scuba diving apparatus, comprising:
a buoyancy compensator attachable to a diver;
and a rate-of-ascent control device for sensing the rate-of-ascent of the diver and for automatically decreasing the buoyancy of said buoyancy compensator when the rate-of-ascent exceeds a predetermined value.
The apparatus according to Claim 1, wherein said buoyancy compensator is an inflatable device attachable to the diver so as to be submerged in the ambient water and to be subject to the pressure thereof;
said apparatus further including a pressurized gas tank also attachable to the diver for inflating said inflatable device;
said rate-of-ascent control device automatically venting the interior of the inflatable device to the ambient water when the rate-of-ascent exceeds a predetermined value.
The apparatus according to Claim 2, wherein said rate-of-ascent control device includes a housing attached to said inflatable device and having an inlet communicating with the interior of said inflatable device, an outlet communicating with the exterior of the inflatable device, a control passageway between said inlet and outlet, and a displaceable member normally closing said control passageway but effective to open said control passageway, and thereby to connect the interior of the inflatable device to the ambient water, when the rate-of-ascent of the diver exceeds a predetermined value.
The apparatus according to Claim 3, wherein said housing further includes a control chamber having a slow-acting vent causing the pressure therein to gradually follow the ambient water pressure; said displaceable member normally being biassed to close said control passageway, but being effective to open the control passageway when the pressure in the control chamber is larger than that of the ambient pressure by a predetermined amount.
The apparatus according to Claim 4, wherein said control chamber is an air chamber located within said inflatable device, and said slow-acting vent is between the interior of the control chamber and the interior of the inflatable device causing the pressure in the control chamber to gradually follow the ambient water pressure.
The apparatus according to Claim 4, wherein said control chamber is an air chamber located externally of said inflatable device, and said slow-acting vent is between the interior of said control chamber and the interior of the inflatable device causing the pressure in the control chamber to gradually follow the ambient water pressure.
The apparatus according to Claim 4, wherein said control chamber is a water chamber located externally of said inflatable device, but includes a gas-filled expansible member which changes its volume inversely with the pressure in said water chamber, said slow-acting vent being between the interior of said water chamber and the ambient water whereby the expansion or contraction of said gas-filled expansible member produces a flow through said slow-acting vent to cause the pressure in the control chamber to gradually follow the ambient water pressure.
The apparatus according to Claim 4, wherein said slow-acting vent is a flow-restrictor orifice.
The apparatus according to Claim 4, wherein said slow-acting vent is a flow-restrictor labyrinth.
The apparatus according to Claim 4, wherein said slow-acting vent is included in a unit having a connector for detactably connecting the unit with respect to a socket formed in said housing.
The apparatus according to Claim 3, wherein said control device further includes a manual member connected to said displaceable member for manually moving it to its open position.
The apparatus according to Claim 3, wherein said displaceable member is a membrane.
The apparatus according to Claim 12, wherein said membrane includes a stem fixed thereto and engaging a valve member normally located to close said control passageway but movable by said stem to open said control passageway.
The apparatus according to Claim 13, wherein said displaceable member is normally biassed to its closed position by a spring.
The apparatus according to Claim 14, further including a cap threaded onto said housing and engageable with said spring thereby permitting a change to be made in the bias applied to said displaceable member.
The apparatus according to Claim 15, wherein said cap is formed with openings leading from said control passageway to the ambient water.
The apparatus according to Claim 3, wherein said inflatable device is a buoyancy jacket.
Scuba diving apparatus, comprising:
an inflatable buoyancy compensator attachable to a diver so as to be submerged in the ambient water and to be subject to the pressure thereof;
a pressurized gas tank attachable to the diver and connected to said inflatable buoyancy compensator for inflating it;
a rate-of-ascent control device including an inlet communicating with the interior of said buoyancy compensator, an outlet communicating with the exterior of said buoyancy compensator, a control passageway between said inlet and outlet, a displaceable member normally biassed to close said control passageway, and a control chamber having a slow-acting vent causing the pressure therein to gradually follow the ambient water pressure, such as to displace said displaceable member to open said control passageway when the pressure in the control chamber is larger than that of the ambient water pressure by a predetermined amount.
The apparatus according to Claim 18, wherein said displaceable member is a membrane.
The apparatus according to Claim 19, wherein said control chamber is a water chamber located externally of said inflatable device, but includes a gas-filled expansible member which changes its volume inversely with the ambient water pressure, said slow-acting vent venting the interior of said water chamber to the ambient water whereby the expansion or contraction of said gas-filled expansible member produces a flow through said slow-acting vent to cause the pressure in the control chamber to gradually follow the ambient water pressure.