Safety device for buoyancy control devices for diving

Abstract

Safety device for buoyancy control devices for diving, comprising: • a comparison chamber • an expandable membrane • an escape chamber • a piston valve • a gasket • a spring • an over-pressure valve • an emergency opening pull-cord • an external tank • an "open / close / automatic" selector • a piezoelectric sensor.

Description

[0001] "SAFETY DEVICE FOR BUOYANCY CONTROL DEVICES FOR DIVING"

[0002] Description

[0003] Field of Application

[0004] The present invention lies in the technological field of underwater safety devices, and more specifically in trim control systems for scuba diving. It regards an automatic device designed to integrate with buoyancy control devices (BCDs) in order to prevent ascents that exceed the recommended safe ascent rate and the attendant risks of decompression sickness (commonly known as the bends). The mechanism is based on a pneumatic principle of pressure balancement and on the ability to release excess air in case critical depth variations occur, thereby ensuring safety of the user.

[0005] Prior Art

[0006] In underwater activities, buoyancy control is a critical factor for both safety and dive effectiveness. The device, subject of the present invention, offers an innovative solution to a problem of considerable relevance in this field. The main issue addressed by the invention is the need to prevent uncontrolled ascents that can occur after a loss of buoyancy control during a dive, with the consequent high risks of decompression sickness and pulmonary barotrauma.

[0007] Current solutions rely predominantly on manual emergency-discharge systems which, although functional, require a direct and prompt reaction by the diver who, depending on experience and other determining factors, may not always be able to respond adequately in critical situations. The comparison, compensation and automatic emergency-release device for buoyancy control vests (hereinafter "BCD") aims to overcome these limitations through a mechanism that, while integrable with existing solutions, provides an automatic action of venting of excess air from the buoyancy control device, hence preventing uncontrolled ascent without requiring user intervention.

[0008] The device comprises at least: a comparison chamber, an expandable membrane, a piston valve with filling and discharge ducts, and an escape chamber provided with a plurality of escape and discharge holes. Its operating principle is based on balancing the pressures between the air in the comparison chamber and the external environment, with the comparison chamber holding a quantity of control air while the escape chamber allows release of excess air present in the BCD bladder.

[0009] The expansion membrane plays a key role in the pressure balancing process, reacting to pressure variations during descent and ascent. The piston valve, with its calibrated ducts, allows airflow and pressure equalization when the device is activated, whereas the escape chamber expels the excess air through its holes.

[0010] In case of an uncontrolled ascent beyond the critical safe speed, being the limited capacity of the draining duct insufficient to manage evacuation of the control air from the comparison chamber, it will determine the expansion of the air present in the comparation chamber, the exercise of a pressure on the expandable membrane, the opening of the piston valve and the consequent quick release of the air contained in the BCD, stopping the uncontrolled ascent.

[0011] This solution is a significant step forward in dive safety, providing an automatic system that lowers buoyancy-related accident risk and that can be integrated with current technologies, thereby enhancing the overall diving experience and adding an extra layer of safety for divers.

[0012] A thorough examination of existing patents is necessary, to highlight the gaps that the present invention intends to fill.

[0013] Patent US 2021 147048 describes a diving BCD comprising at least one variable-volume air chamber bounded by an outer wall and an inner wall, a waist-closure strap and a removable coupling device between the inner wall and the strap. The device includes first and second connectors respectively attached to the inner wall and strap, a retainer that holds the second connector on the first along an axis substantially orthogonal to the strap, and a mean of rotation, on said axis, of the second connector respect to the first. Although this solution may provide modularity and configurational flexibility, it does not address directly the uncontrolled ascent problem, resulting from loss of buoyancy control during a dive. The automatic-release comparison and compensation device, subject of the present invention, overcomes that limitation with a mechanism that acts automatically to release excess air, not requiring direct diver action.

[0014] Patent CN 211731768 (U) proposes an innovative diving apparatus that facilitates both flotation and submersion. The system comprises floating breathing equipment and a connected breather, an inflatable lifejacket linked to the breathing equipment. An inflatable cavity is formed in the lifejacket, with an inflation port and a drain port connected to the cavity; the jacket is connected to the breathing equipment by a sealed air tube. One end of the tube is connected to the breathing apparatus, the other to the jacket, and the inflation port is connected to the sealed air tube. Albeit this system supplies breathable air to the diver and the possibility to inflate the jacket for controlled buoyancy, it does not focus on uncontrolled ascent caused by inadequate buoyancy management.

[0015] Both mentioned documents, though representing progress in underwater equipment, do not provide a comprehensive solution to the problem identified earlier. The automatic-release comparison and compensation device described in the present invention distinguishes itself by its capacity to prevent uncontrolled ascent through an automatic mechanism that requires no diver action. This is a crucial feature for improving dive safety, reducing risk of buoyancy-related accidents, especially for inexperienced divers or during training courses, where uncontrolled ascents are more likely to happen.

[0016] In conclusion, the automatic-release comparison and compensation device represents a necessary as far as innovative solution to face buoyancy management during diving activities, offering a higher level of safety than currently available technologies. A detailed explanation of the inventive concept will follow in subsequent sections of this document, further outlining the significant contribution of the invention to the field of scuba diving industry.

[0017] Description of the Invention

[0018] With the present industrial invention patent application, the Applicant intends to describe and claim a system providing at least one new and alternative solution to those hitherto known, and / or to satisfy one or more needs felt in the technical field, in particular as can be inferred from the foregoing.

[0019] A buoyancy control device (BCD) is an aid for correcting trim (buoyancy) during a dive and is considered as an almost indispensable accessory for diving activities (certain recreational diving training agencies deem it mandatory). It is normally constructed as a vest, worn over the wetsuit and comprises a number of distinctive elements. an air reserve bag extending over the entire surface of the vest that can be inflated (with cylinder's air) or deflated as required; a rigid backplate to which the cylinder is secured; pockets for holding ballast weights and, two manually operated safety valves, actuated by a pull-cord, usually located respectively in the shoulder area and the lumbar area.

[0020] These valves are necessary because, if the BCD was over-inflated, it would exert a positive buoyant force that can cause an uncontrolled ascent (with serious consequences for the diver's health). Their position allows complete evacuation of air regardless of the diver's body orientation, since at least one of the two valves will be in the uppermost part of the body (thus preventing formation of pockets where air could be trapped). The system has yet a limitation which dwells in the diver who must know his or her position at the above-mentioned event - perception that is not always clear underwater, especially for inexperienced divers - in order to choose the appropriate valve to operate to obtain the desired effect. Furthermore, although the pull-cords' positions are familiar to the BCD user, locating them in a moment of stress may not always be immediate.

[0021] The concept and necessity of the comparison, compensation and automatic emergency release device for buoyancy control devices arise from the necessity to create an automatic system which can assist or, in its more advantageous forms, replace the current manual opening and emergency release systems of a BCD's air reserve., so as to prevent loss of control of buoyancy that may lead to an uncontrolled ascent, which would entail a very high risk of decompression sickness ('the bends') and pulmonary barotrauma, if the proper emergency actions are not taken. The goal, being the system able to be integrated with currently available accessories, is to realize an extremely simple and effective mechanism.

[0022] To achieve this purpose the inventor has devised a valve which, based on a pneumatic principle, comprises at least:

[0023] • a comparison chamber;

[0024] • an expandable membrane fitted with a suspension acting as an elastic surface, allowing the correct movement of said membrane;

[0025] • a piston valve which, through a filling duct and a calibrated draining duct formed inside its shaft, puts the BCD's air reserve chamber in communication with the comparison chamber; • an escape chamber having, on its body, a plurality of escape holes and a plurality of discharge holes;

[0026] • an over-pressure valve apt to release the air contained in the BCD's air chamber upon reaching an internal (of said chamber) pressure threshold limit;

[0027] • a pushing spring for said piston valve, conveniently dimensioned to keep the piston valve in closed position during normal operation, that is, until the condition arises in which said piston valve must open.

[0028] In further optional and advantageous forms of realization, the invention may also comprise:

[0029] • a gasket, for nonlimiting example a rubber 'O-ring', apt to seal said piston head so as to prevent unwanted air leakage from the BCD's air chamber to the external environment;

[0030] • an emergency pull-cord for manual operation of the device;

[0031] • a selector allowing the behavior of said piston valve to be chosen, said device behavior being automatic, always-open or always- closed; the details of these behaviors will be explicated later;

[0032] • a coupling system for the installation of the device on existing buoyancy control devices (BCDs).

[0033] The operating principle relies on the pressure variations occurring during descent and ascent in a dive, and on the equalization of the pressure of the air contained in the comparison chamber, henceforward referred to as control air, and the air contained in the BCD's air reserve chamber. The comparison chamber, whose volume is calibrated, is intended to contain the quantity of control air coming from the BCD's bladder, introduced via the filling duct (and to a lesser extent via the draining duct). The filling duct allows airflow in one direction only: from the BCD bladder toward the comparison chamber. Once the air has entered the comparison chamber it begins to exert pressure on the piston-valve membrane as its volume changes (depending on depth). To keep the pressure inside said chamber balanced with the external pressure, the draining duct is used which, with its bore, will let the air flow out at a rate that determines the safe ascent-rate limit for the diver. Beyond that limit, the draining duct flow capacity can no longer sustain the flow resulting by the expansion of the control air, which will consequently begin to exert a positive force on the membrane, which will consequently displace the piston valve causing the release of the air contained in the BCD bladder. This would immediately stop the uncontrolled ascent of the diver, restoring his trim. The earlier- mentioned issue of the diver having to choose which manual valve to operate is likewise resolved, since the device acts autonomously and independently.

[0034] In a more advantageous version of the invention, the thickness and / or the volume of the comparison chamber is drastically reduced by the addition of an external tank connected to said chamber via a fitting, said tank being conveniently housed on the BCD.

[0035] Said comparison chamber is placed on top of the escape chamber. The latter has, at its base, a flush surface apt to form a seat for the head of the piston valve, which faces towards the BCD - i.e. in the direction of the piston stroke during valve's actuation. The comparison chamber may further include a coupling system allowing to adapt the device to existing BCD coupling systems. The piston valve has two channels formed inside its shaft, of which one, of larger bore and unidirectional, referred to as filling duct, is apt to permit passage of air from the BCD bladder into the comparison chamber, whereas the other, of smaller bore and bidirectional, referred to as draining duct, apt to permit equalization of the external pressure with that of the air contained in the comparison chamber. The cross-section of said channels is determined such that the air flow is facilitated through the wider filling duct, whereas through the draining duct airflow occurs without difficulty only up to the safe ascentrate limit.

[0036] The escape chamber has, on its lower surface, a plurality of escape holes (for the air contained in the BCD bladder) and, on its lateral surface, a plurality of discharge holes (for the same air). The two chambers, whose outer bodies are directly coupled, are internally separated by the expandable membrane, which may be made of any material, silicone being preferred. Said membrane is subject to the pressure exerted by the air in the comparison chamber, counteracting the pressure exerted on the piston-valve head by the air external to said chamber. As long as the ascent-rate value lays within the determined safety limit (which will depend, as noted, on the parameters of the training agency chosen when the device is produced, and according to which said parameter is set and the invention implemented), given the bore of the draining duct, the pressure of the control air - whose volume, as said, varies with the depth - can be balanced with the pressure of the air in the BCD bladder, hence exerting neutral pressure on said membrane. When the ascent exceeded the critical rate, the draining duct flow capacity would no longer be sufficient for the expansion needs of the control air, which would then begin to exert positive pressure on the membrane which, being connected to the piston-valve shaft, opens the latter, rapidly releasing the excess air that has built up in the BCD bladder so to abruptly terminating the uncontrolled ascent.

[0037] An emergency pull-cord may additionally be provided, to actuate the valve manually whenever the diver deems it necessary, just as with the conventional manual valves already present on every BCD.

[0038] In a further embodiment the device may be fitted with a selector that mechanically governs the piston valve's behavior in three different configurations:

[0039] • automatic - the valve operates autonomously according to the principles described thus far;

[0040] • closed - pneumatic opening is inhibited and the device behaves like a conventional manual valve, permitting manual opening via the pull-cord;

[0041] • open - pneumatic opening is inhibited and the device is locked in the open position; this configuration overlooks the potential situation in which the BCD's manual inflation device (VIS - variable inflating system) has a leak or a malfunction that wouldn't let the air inflow into the BCD bladder to stop.

[0042] A further accessory of the device is a piezoelectric sensor apt to detect valve actuation. Said sensor can be connected to a wearable device such as, for example, a dive computer with wireless connectivity, thereby providing the diver with visual and audible feedback that the device has been triggered.

[0043] Description of the Figures

[0044] The first figure is a sectional view of the entire body of the device, showing every element constituting it.

[0045] Starting from the top, the comparison chamber 1 placed on top of the expandable membrane 2, whose curved portion, previously defined as the suspension, allows the membrane 2 to flex. Moving downward, the escape chamber 3 is encountered; in which there is the shaft of the piston valve 4, directly connected to the membrane 2. The head of the piston valve 4, located beneath the lower face of the escape chamber 3, resting against the gasket 9 - when in closed position - prevents the air contained in the BCD bladder from being released. Two ducts can be identified inside the valve shaft: on defined as filling duct 5, unidirectional, apt to permit airflow from the BCD bladder into said comparison chamber 1 and the other, defined as draining duct 6, apt to permit balancing the pressure of the control air (contained in said comparison chamber 1) with the air present in the BCD bladder during depth changes. On the vertical surface of said escape chamber 3 there is a plurality of discharge holes 8, while on its lower surface there is a plurality of escape holes 7; all apt to allow, upon triggering of the device, the discharge of air from the BCD bladder out. In figure 1 are also visible the over-pressure valve 15 and the spring 14 for the piston valve.

[0046] The second figure shows a sectional view of the complete device highlighting an external tank 10 for said comparison chamber 1 , allowing the latter to be realized with drastically reduced thickness and / or volume. A selector 11 can be seen, apt to allow among three operating configuration choices: open, closed, or automatic. The coupling system 12 is also visible, allowing the device to be adapted to conventional BCDs. The third figure shows the device in triggered position, i.e. when the piston valve 4 has been opened, winning the force of said spring 14. To meet the condition depicted, an excessively rapid ascent has to be occurred, which produced the expansion of the control air such that its pressure can not be equalized through the draining duct 6, hence beginning to exert positive pressure on the membrane 2 which opens the piston valve 4, releasing the air contained in the BCD bladder, which will then vent through the indicated path.

[0047] Detailed Description of the Invention

[0048] It will be immediately clear that numerous variations and modifications, e.g. to shape, size, arrangement, or the use of parts having equivalent functions, may be made still laying within the scope of protection of the invention as defined in the appended claims. The present invention represents a safety device for scuba-diving activities equipped with a pneumatic relief valve that releases excess positive pressure generated by an accidental uncontrolled ascent during a dive. With reference to Figure 1 , the invention comprises at least a comparison chamber 1 laying on an escape chamber 3, the outer bodies of the two chambers being directly coupled while internally interposed, to separate them, there is an expansion membrane 2 equipped with a suspension that permits movements in the cases previously described. Said escape chamber 3 is provided, at its base, with a plurality of escape holes 7 and, on its vertical surface, with a plurality of discharge holes 8. A piston valve 4 is housed inside said escape chamber 3, whose head, while in normal position, laying against a gasket 9, prevents the air contained in the BCD bladder from being released.

[0049] Retention of the piston valve 4 in closed position, until pressure conditions required for its opening are reached, is ensured by a dedicated spring 14 whose force is calibrated so that it can easily be overcame by any overpressure in the comparison chamber 1 relative to the external pressure, thereby triggering the device and restoring safe conditions for the diver. The safety device further comprises an over-pressure valve 15 apt to release air contained in the BCD bladder when an internal threshold pressure is reached, said threshold being determined in accordance with the construction materials of said BCD. It is clear that modifications or variants to the invention thus far described may be made, which would be obvious to a skilled person, without thereby leaving the scope of protection declined by the appended claims.

Claims

Claims1 . Safety device for buoyancy compensation devices for scuba diving - the buoyancy compensation device hereafter on defined as "BCD" - for being used on a common BCD to prevent an uncontrolled ascent of a diver in case of loss of balance during a dive, said BCD including an air bag for giving to said diver a dynamic buoyancy reserve, characterized in that it comprises:• a comparison chamber (1) containing a reference quantity of air for providing the parameter of air pressure to be compared with the BCD air reserve pressure;• an expandable membrane (2) apt to convex only in case diver's diving ascent rate exceeds the safety limit rate, said limit rate to be defined based on the chosen dive training organization's teaching parameters, said excess in ascent rate causing a volume variation of said reference quantity of air in such a way that it becomes impossible to balance the pressure of said reference air with the air contained in the BCD air reserve bag, causing said membrane (2) to warp and a piston valve (4) to open;• said piston valve (4) fitted at least with:■ a spring (14) for keeping said piston valve (4) in its closing position as long as inside said comparison chamber (1) a positive pressure does not raise, compared to the external pressure;■ a filling duct (5) of said comparison chamber (1);■ a draining duct (6) of said comparison chamber (1); said filling duct (5) having a bigger bore that said draining duct(6), specifically, the draining duct (6) bore being calibrated to allow outwards air flow from said comparison chamber (1) only within said safety ascent limit rate; within that limit, said piston valve (4) lies in closed position by action of said spring (14), exceeding said safety ascent limit rate will determine said piston valve (4) to open, consequently opening escape holes (7) and discharge holes (8);• an escape chamber (3), fitted with a plurality of said escape holes(7) and a plurality of said discharge holes (8) for the air contained in the BCD air reserve bag;• an overpressure valve (15) for releasing the air contained in the BCD air reserve bag when an internal pressure limit is reached.

2. Safety device for buoyancy compensation devices for scuba diving, as claimed in previous claim 1 , characterized in that it comprises:• a comparison chamber (1) containing a reference quantity of air for providing the parameter of air pressure to be compared with the BCD air reserve pressure;• an expandable membrane (2) apt to convex only in case diver's diving ascent rate exceeds the safety limit rate, said limit rate to be defined based on the chosen dive training organization's teaching parameters, said excess in ascent rate causing a volume variation of said reference quantity of air in such a way that it becomes impossible to balance the pressure of said reference airwith the air contained in the BCD air reserve bag, causing said membrane (2) to warp and a piston valve (4) to open;• said piston valve (4) fitted at least with:■ a spring (14) for keeping said piston valve (4) in its closing position as long as inside said comparison chamber (1) a positive pressure does not raise, compared to the external pressure;■ a filling duct (5) of said comparison chamber (1); o a draining duct (6) of said comparison chamber (1); said draining duct (6) being provided with a removable nozzle - e.g. a gicleur valve - for setting the flow rate of said draining duct(6), for allowing to choose the desired safety ascent limit rate; specifically, the air flow of said nozzle being calibrated to allow outwards air flow from said comparison chamber (1) only within said safety ascent limit rate; within that limit, said piston valve (4) lies in closed position by action of said spring (14), exceeding said safety ascent limit rate will determine said piston valve (4) to open, consequently opening escape holes (7) and discharge holes (8);• an escape chamber (3), fitted with a plurality of said escape holes(7) and a plurality of said discharge holes (8) for the air contained in the BCD air reserve bag;• an overpressure valve (15) for releasing the air contained in the BCD air reserve bag when an internal pressure limit is reached.

3. Safety device for buoyancy compensation devices for scuba diving, as claimed in previous claim 2, characterized in that said nozzle - e.g. a gicleur valve - comprises an electric programmable actuator, as non restrictive example by a computer with a dedicated interface and software application, said actuator allowing to choose the preferred safety ascent limit rate without having to act mechanically on the device itself.

4. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that it comprises a seal, as non restrictive example an "o-ring", for isolating said escape chamber (3) as long as said piston valve (4) lies in its closing position.

5. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that it comprises an emergency cord (13) for manual opening of said piston valve (4).

6. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, wherein said comparison chamber (1), said escape chamber (3) and said piston valve (4) can be made of metallic material, as non restrictive example alloy or its variants, titanium, steel or its variants, or of polymeric material, as non restrictive example ABS, PE, HDPE, PTFE, PEEK or of composite material.

7. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that the base ofsaid escape chamber (3) includes a coupling system (12) for the device's application on a BCD.

8. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that said comparison chamber (1) is connected to an external tank (10) in order to reduce the thickness and / or the volume of said comparison chamber (1).

9. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that it comprises a selector (1 1) for choosing the behavior of said piston valve (4), allowing three different configurations:• "automatic": the device acts automatically, consequent to the volume variation of the reference quantity of air contained in the comparison chamber (1);• "closed": automatic pneumatic opening is inhibited and the device act as a normal manual vent, allowing to be operated by mean of said cord (13);• "open": automatic pneumatic opening is inhibited and the device is blocked in opening position, this configuration to be used in the event the BCD's manual inflating device should leak or fail.

10. Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that it comprises a piezoelectric sensor for detecting weather the device is workingproperly, said sensor being fitted with a wireless communication module, able to connect with a wearable device, as non restrictive example a diving computer, to provide the user with visual and audible feedback of the device's function.11 . Safety device for buoyancy compensation devices for scuba diving, as claimed in any previous claim, characterized in that said draining duct (6) of said comparison chamber (1) is made with a hollowed threaded insert, which makes it able to be replaced.

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