GB2328881A - Shallow dive breathing device - Google Patents

Abstract

The device, which is for use in water no more than 12 feet deep, comprises a body defining an air chamber 2 with a mouthpiece 1, an air control valve 4, an air supply pipe 5 and a non-retum air outlet valve 6, and includes a diaphragm 3 for controlling the air supply and having a surface area large enough to allow the action of breathing to open the valve 4. Ports 8 in a cover plate 9, which secures the diaphragm, allow water in and out to facilitate movement of the diaphragm. The valve 4 may be depressed manually via an access hole 7 in the cover plate to purge the air chamber with air. A low pressure air supply is provided by bellows via an air reservoir.

Description

SHALLOW DIVE AXR COWTROt VALVE This invention relates to a device which enables breathing underwater.

There are wany sophisticated types of devices on the market for breathing underwater, both for commercial application and leisure activity (Scuba- self contained underwater breathing apparatus), which when supplied with high pressure air, allow a person to breath under water to depths of up to 60 metres (200ft) and, with special equipment greater depths.

The main disadvantages of these devices are their expense and -complexity, so that a per-son ha-s to be highly trained to use them for without adequate training it is dangerous to use this equipment.They need expensive ancillary equipment such as steel bottles or similar suitable containers able to withstand air pressure of up to 320bars (435-opsig), held in special harnesses, to provide the air to the devices; protective clothing and lifejackets.

These devices -are known in the diving world a-s air regulators. They have many working parts, some being spring loaded and are precision made to extremely fine tolerances. Some of these parts have to withstand these high pressures and are lubricated with special silicone grease, necessitating regular maintenance.

The function of the above describe air regulators for underwater breathing is to reduce safely and reliably this high pressure down to O.OO5bar t2.5 inches wghto enable the user to inhale.

There are many instances of death and /or serious bodily harm through inexperienced persons using this equipment or because of equipment malfunction.

According to the present invention low pressure air at a pressure of approximately 0.3-63bar (5.33psig)can be supplied to the device by us of a foot operated bellows (or any other low pressure air supply) with attendant flexible piping to enable its use to a maximum depth of 3.66 Mts. tlSft). This device is designed so that it will not operate satisfactorily with a differential pressure higher than O.368bar (5.33psig)between the device and ambient.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings - Drawing 1/2 -Fi-g,1 shows in perspective how the device works.

When the invention is held in the mouth by means of the mouthpiece 1 and a person inhales, the pressure in the air chamber 2 is reduced, the diaphragm 3 is pushed inwards by the now higher water pressure thereby opening the air control valve 4 which allows air in the air supply pipe 5 to flow into the air chamber 2 and then on through the itiouthpiece 1 into the lungs of the inhaler.

When this process is terminated, the diaphragm 3 and the air control valve -4 return to their origin-al p-osition.

When exhalation takes place, the air expelled through the mouthpiece 1 raises the pressure in the chamber 2 above that of the surrounding water, this forces opn the air outlet valve 6 and the expelled air is diffused into the water.

Should the air chamber need to be purge-d with air, this is achieved by depressing the air control valve 4 manually with a finger through the access hole 7 in the cover plate 9.

-The port-s 8 in the cover plate 9, which secures the diaphragm 3, allow water in and out to facilitate movement -of the diaphragm 3.

There are numerous examples of how this invention could be used.

Referring to Drawing 2/2 Fig,1 gives a specific example of how a person is u-sing the invention to en-able a photograph to be taken of the condition of a boats propeller.

The air supply operator A works the bellows B to produce low pressure air at 0.368 bar (5.33psig) which is carried va the flexible hose C to the air reservoir D and then on down to the person F below the water surface E, who is using the invention G.

An air control valve as shown in Drawing 1/2 Fig,1, which when held in the mouth by means of fixture 1 and supplied with air at a pressure of 0.363bar (5.33psig) enables a person to breath under wat-er down to a depth of 3.66Mts (12ft).

There are four main features in the valve.

By the use of the ability of the lung of a normal person to vary the pressure in a -small comp-artment which is in communication with a diaphragm, this variation will cause the diaphragm to move. This movement can then be used to open a valve against a much higher pressure than that of the compartm-ent provided that the surface area of the diaphragm is much greater than that of the air valve.

The ratio will vary depending upon the differential of th pressure involved.

2 The effective area of the air inlet valve must be of sufficient size to allow enou-gh air to pass through the valve to satisfy the requirement of the user.

Also th-e outlet valve from the compartment must be large en-ou-gh and be suitable positioned to allow easy discharge of water from a low point in the valve.

3 Means must be provided to expel any water that may collect in the compartment. In this case, manual depression of the diaphragm allows air at a high-er pressure to that of the surrounding water into the air compartment, thus forcing any water out via the air outlet valve.

Basis for Calculations 1 Bar = 14.50 psig = 32.625 feet head of average density sea water 1 psig = 2.25 head -of sea water.

12ft = 12/32.625 *1 -= 0.368 bar = 5.33 psig 1 cubic ft = 1728 cu ins = 28.32 ltrs

Claims (6)

1 A shallow (n-o -deeper th-an 3.66Mts (l2ft) underwater breathing d-evice comprising a plastic or other suitable material body which has a mouthpiece for gripping the device, a neoprene or suitable material diaphragm, (with a surface area ratio to that of the air control valve large enough for the action of breathing to open the air valve), necessary to control the air inlet supply, a non c6rrosloe air control valve, an air inlet connection and a non corrosive non-retrn valve as the air outlet valve.

2 A shallow underwater breathing device as in Claim 1 wherein the device will not operate in a satisfactory manner with a higher differential air pressure between the device and ambient of more than O.368bar (5.33psig)

3 A shallow underwater breathing device as claimed in Claim I or Claim 2 which when supplied with air at O.3-68bar (5.33psig) at the surface will limit the operational depth under water to 3.66Mts -(i2ft).

4 A shallow underwater breathing device as -Claimed in Claims i to 3 which because of its simplicity of design and limitation -of-depth to 3.66Mts 12ft can be used successfully after a few minutes familiarisation with the device, by a person able t-o swim.

5 A shallow underwater breathing device as Claimed in Claims 1 to 4 which is inexpensive and reliable because of its simplicity of design, large clearances between any moving parts, non r-equirement of any lubrication, limitation of use and non requirement of expensive ancillary equipment.

6 A shallow underwater breathing device as Claimed in Claims 1 to 5 which because of its design and construction simplicity is virtually maintenance free.