Field of the Invention

The present invention relates to the field of diving apparatus. More particularly, the invention relates to an automatic garment-mounted buoyancy generator.

Background of the Invention

Diving apparatus having a significant weight generally comprises breathing apparatus including a diver-carried gas cylinder containing breathable pressurized gas, a buoyancy compensator that includes an inflatable bladder for adjusting the buoyancy of the diver underwater, and a weighting system which counteracts the buoyancy of other components of the diving apparatus so that the diver will be able to descend when desired. The weighting system is unable to interact with the breathing apparatus.

It is an object of the present invention to provide an automatic garment-mounted buoyancy generator that will reliably cause the user to ascend within a body of water to the upper water surface when triggered by predetermined conditions of distress.

It is an object of the present invention to provide an automatic garment-mounted buoyancy generator that prevents the diver from being subjected to decompression sickness, which results from ascension within a body of water at an excessive rate that causes bubbles of inert gases to be formed within tissues of the body, leading to joint pain and even to death.

It is an additional object of the present invention to provide an automatic garment-mounted buoyancy generator which is triggerable by a settable level of distress conditions.

Other objects and advantages of the invention will become apparent as the description proceeds.

Summary of the Invention

An automatic garment-mounted buoyancy generator comprises an airbag mounted on a garment of a user desirous of engaging in a water activity, a compressed gas container in controllable fluid communication with an interior of the airbag, a controller operable to cause injection of gas discharged from the gas container into the airbag interior following determination of one or more preset distress conditions, a depth sensor and a digital timer for determining a duration of the user found to be underwater following commencement of the water activity, wherein the one or more preset distress conditions are selected from a deviation from input signals provided by one or more of the depth sensor and the digital timer.

In one embodiment, the controller is operable to cause injection of the gas discharged from the gas container into the airbag interior for a sufficient duration during a first step to generate a buoyancy force that allows the diver to ascend at a rate less than a predetermined decompression sickness susceptible rate, and to suppress injection of the gas for a sufficient duration during a second step following the first step to produce an automatic decompression stop.

Brief Description of the Drawings

In the drawings:

- Fig. 1 is a block diagram of an embodiment of an automatic garment-mounted buoyancy generator.

Detailed Description of the Invention

Fig. 1 is a block diagram according to one embodiment of an automatic garment-mounted buoyancy generator, indicated generally by numeral 10. Buoyancy generator 10 is independent of, and separate from, any diving apparatus, and therefore may be mounted on any adult or child user desirous of undertaking a water activity even if the water activity is not a diving operation. Buoyancy generator 10 is triggered by preset distress conditions, and is consequently suitable for rescuing a diver who has difficulty in breathing or preventing a child at a pool from drowning.

Buoyancy generator 10 comprises airbag 7, compressed gas container 9, for example containing compressed carbon dioxide, in controllable fluid communication with the interior of airbag 7, motor 11 adapted to cause a discharge port of compressed gas container 9 to become controllably unoccluded following transmission of a triggering signal, a plurality of sensors 13 each of which adapted to detect values of a different user-related bodily parameter, controller 20, e.g. the Arduino ATmegal6U2 which has built-in support for USB, for receiving the signals generated by each sensor 13 and for commanding operation of motor 11 according to stored instructions when the received signals are indicative of preset distress conditions, and power supply 24 for powering motor 11, sensors 13 and controller 20. Motor 11 may be a servo motor which is suitable to produce motion of its output shaft in alternating rotation directions of up to 180 degrees.

Exemplary sensors 13 include a depth sensor, such as the BMP180 barometric sensor manufactured by Bosch, for determining the real-time depth with an accuracy of approximately 10 cm, a digital timer, an analog pulse sensor, and a digital gas flow sensor.

In one embodiment, buoyancy generator 10 will be triggered when controller 20 detects a deviation from the input signals provided by one or more of the depth sensor and the digital timer. For example, when the user is a child user at a pool, distress conditions may be defined when the user is at a depth of 0.8 m for two seconds. For a diver, distress conditions may be defined when the user is at a depth of 30 m in order to avoid manifestation of decompression sickness.

In another embodiment, buoyancy generator 10 will be triggered when controller 20 detects a deviation from the input signals provided by one or more of the depth sensor, the digital timer and the analog pulse sensor, the latter detecting abnormal breathing patterns.

The preset distress conditions that trigger operation of buoyancy generator 10 are entered to controller 20 through interaction with interface 15. Interface 15 may be a visible graphical user interface in data communication with controller 20, and may be worn on the wrist as a watch so as to be accessible to the user underwater. Alternatively, interface 15 may be accessed in dry, out of water conditions, of particular utility when buoyancy generator 10 is worn by a user such as a child user and a caretaker enters the preset distress conditions. Preferably, the weight of the user including apparatus carried thereby (hereinafter the "loaded weight") is also entered to controller 20. Interface 15 may be accessed by a computer or by a mobile phone.

Buoyancy generator 10 is mounted on garment 5, which is generally worn on the upper body, but which also may be worn on any other bodily part. Garment 5 may be a T-shirt made of lightweight, stretchable and waterproof Lycra ^® which is resistant to solar irradiation and adapted to retain the body warmth, or of any other similar material, or alternatively may have shoulder straps. Garment 5, due to its lightness, will not interfere with diving apparatus, if used. All components of buoyancy generator 10 are waterproof and are mounted on garment 5 by waterproof mounting elements. Airbag 7, normally mounted in a compacted condition, is adapted to be inflated to a predetermined size in order to generate user-specific buoyancy that is needed during the preset distress conditions, and is sufficiently airtight to prevent the escape of the inflation inducing gas from its interior.

Airbag 7 may be attached to an anterior portion of garment 5, such as an abdomen covering portion, in order to generate a righting moment when the user is engaged in a diving operation and the airbag has been inflated. Since the head of the user is usually slightly below the feet during a diving operation, inflation of the airbag that generates increased upwardly directed buoyancy causes the diver's body to rotate about his or her center of gravity when ascending to the upper water surface until the head is higher than the feet.

Airbag 7 may be made of a drop stitch fabric matrix. Drop stitch fabric matrices are produced by weaving yarns, such as polyester, Kevlar and other polymeric fibers, between two or more fabric sheet layers, such as made of PVC, which are spaced a specific distance apart from one another. A typical drop stitch fabric matrix may include a large number, e.g. on the order of thousands, of vertical fibers of uniform length.

The yarns may be woven in a straight line along the continuous direction axis so as to be in line with the warp yarns. After being pulled though a fabric layer, they may be wrapped over and under multiple weft yarns following next to the adjacent warp yarn in the pattern. The drop stitch yarns may be patterned to form evenly spaced rows. In this fashion, the yarns are ensured of not unraveling, while the matrix has a density for example of at least 50 threads per square inch and a thickness ranging from 2-30 inches. Once the matrix is woven together, an airtight coating or laminate is bonded to the fabric sheet layers. The drop stitch fabric matrix is thus, when inflated to a relatively high pressure, imparted with good resistance to flexing.

An important aspect of buoyancy generator 10 is the ability to cause a diver to ascend within a body of water to the upper water surface, when triggered by predetermined conditions of distress, without being subjected to decompression sickness. In order to avoid decompression sickness, controller 20 commands compressed gas to be discontinuously injected into the interior of airbag 7. That is, the compressed gas is injected for a sufficient duration in a first step to generate a buoyancy force that allows the diver to ascend at a rate less than a decompression sickness susceptible rate (DSSR), e.g. 10 m/min, which is based on physiological considerations and on the data entered to controller 20. In a second step, the discharge port of compressed gas container 9 becomes occluded for a predetermined duration due to temporary cessation of the operation of motor 11. During this second step, the buoyancy force previously generated in the first step becomes counterbalanced by the loaded weight of the diver, and the ascension of the diver becomes stalled, after the diver achieves an equilibrium height. This automatic decompression stop effectively serves to avoid diffusion of inert gas bubbles outwardly from body tissue which are liable to block the arterial blood supply and lead to decompression sickness. The first and second steps may be repeated, for the same or different durations, depending on the remaining depth below the water surface.

Of course, if the digital gas flow sensor is indicative that there is a dangerously low supply of compressed gas remaining in container 9, controller 20 will suppress the second step so that the diver will ascend at a maximum rate to the water surface despite the risk of being subjected to decompression sickness.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried out with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without exceeding the scope of the claims.