AU8275787A - Heated suit for divers - Google Patents

Description

TJEftT_P PP FOR DIVERS

The invention relates to heated suits particularly/ but not exclusively, for deep sea divers.

There are many situations in diving, particularly at depth, where some form of body heating is required to keep a diver warm.

One system uses hotwater heating. Thediver wears a loose fitting suit of a flexiblematerial such as neoprene intowhichwarmwater is pumped. Thewater is forced out at thewristandanklecuffsand is replenished tokeep thetemperaturewarm. Anetwork of small-borepipesmaybeprovided for the water. In such arrangements the diver carries a container in which there are: a heater, a pump and safety circuits, with the electrical supply tothe heater being provided f omthe surface or a diving bell. To provideadiver with sufficient heat in these arrangements a large power input is required. For example, toprovide each oftwodivers at 300mdepthwithlkwworthofheat requires 200kW of power at the surface. At a depth of 450m, 500kW is required. This type of heating is ver> inefficient, requires a large £ower input and has a further disadvantage in that temperaturecontrol becoroesvery difficult with increasing depth. _A small shi or a submersible cannot provide such high power levels so this form of heating can only be used for deep diving from large vessels with high power generating capabilities.

An alternative form of heated suit uses heating of electrical wires. Suits heated by direct current heating can be supplied by 24V batteries. However, currents of up to 30A are required and this means that a very high level of protection is necessary for the diver, with monitoring of the insulation and wiring. Safety circuits, with automatic cut-off in the event of a fault occurring, have to be included. A further problem is the provision of suitable sockets to connect the power supply to the diver. Effective connections are hard to achieve and the presently available 3-ρin sockets are heavy, cumbersome and expensive.

High frequency alternating current heated suits have been proposed. These fall into two categories: that where the high voltage high frequency ac is transformed remotely and low voltage ac is transmitted to the diver, with the resulting potential los&es during transmissions; and that where the high voltage is transformed by a diver-carried transformer to a low voltage, the low voltage hf ac being used to heat the suits. These arrangements however have all involved direct connection of the suit with potentially hazardous high voltage circuit elements, with the consequent possibilities of short circuit problems causing danger to the diver.

The object of the invention is to provide a lightweight suit for diverswhichcanbeheatedeasilyandsafelywithouttheneedforalargepower supply.

The invention provides a means for providing heating for a diver comprising: a) a suit; b) one or more electrically independent wiring circuits distributed over the suit; c) a high frequency power supply; and d) a releasable inductive coupling to connect the suit wiring circuits to the high f equency power supply; wherein the provision of high frequency electrical current to t e wiring- circuits causes heat to be generated in the wires to heat the suit.

Preferably the inductive coupling comprises two parts: an outer primary coil arrangement connected to thepower supply; and an inner coaxial secondary coil arrangement connected to the suit. The secondary coil arrangement is formed so as to be releasably located in the centre of the primary coil arrangement whereby the suit can be connected or disconnected from the power supply as required.

The hf power supplymayeither becarriedbythediver or be situated awayfromhim. Ifthehfpowersupply iscarriedbythediver, thesupplymay include an input for connection to a low voltage dc source located at the su face of inadiving bell. If thediverdoes notcarrythehfpowersupply the quick release coupling has safety advantages in that it allows rapid connection/disconnection of the suit to the power supply with low insertion/withdrawalefforttoplugandunplugthesuit. Itcanalsosafely be connected or disconnected when the power is switched on.

Preferably the suit wiring circuits are wired and arranged so as to minimise inductance effects.

Advantageously there are a number of independent wiring circuits, for example five circuits can provide heating to the whole body without risking cross-chest currents. For safety reasons the circuits should preferably be arranged so that there is nochance of a cross-chest current in the event of a fault or break in a wire. This is because the heart current factor is the most important consideration medically.

Preferably the safety limits of thewiring and insulation in thesuit and the power input are such that there is nodanger to the diver if anywater leaks into the diving suit. Thus excessive protection against leaks will not be necessary.

Ithasbeen foundthat forcomfortdifferentparts of thebody require different amounts of heat. This can be advantageously controlled on the suit by varying the density of the wiring with greater weighting being given to those areas such as the legs which require more heat.

Preferably the suit can provide sufficient heating for a diver at depths of at least 450m.

Preferably the power supply includes a means to monitor the load being supplied and to regulate thepower output in response to changes in the load.

In otder that the invention may be n re ull^ understood one embodiment thereof will now be described, by way of e>t i l only with reference to the accompanying drawings of which;

Figure 1 shows, in front viewandpartlycut away. & si it according to the invention for providing a diver with heat; Figure 2 shows a rear view, partly cut away, of the suit s own in Figure 1.

As shown in Figures 1 and 2 a diver 1 wears a suit 2 inside his diving suit 3 (shown cut away over the body) . The suit 2 is heated by means of high frequency electrical current passing through wiring circuits, 4a to e, distributed over the suit 2. There are five independent circuits: left arm and front, 4a; right arm and front, 4b, left leg, 4c; right leg, 4d; and back 4e. The high frequency electrical current is fed to the wiring circuits via a cable 5 f om which wires pass to all the wiring circuits 4. The power is provided by means of a high frequency power supply 6 contained within a tubular socket arrangement 11. The hf £©wer supply 6 provides hf alternating current byDeans of an oscillator circuit which is drivenby a dc electrical supply suppliedvia a cable10 fromadivingbell or surfacesupply (not shown) . The hf power supply 6 excites coils 7 (showncut away) which act as the primary coils of an air-core (or water-core) type transformer or inductive coupling. The current in the coils 7 induces current in coils 8 wound on a "wand" arrangement 9 inserted into the centre of the coils 7 and hence provides current via the cable 5 to the suit 2.

Thehigh frequencypower supply6canalternativelybecarriedbythe diver, with thecable10 from thedcelectrical supplyprovidingpower to the unit carried by the diver and the "wand" arrangement allowing a safe, convenient plug-in means for the diver to connect his suit to the power supply. If the hfpower supply 6 is carriedbythediver, or suspended near him as shown in the figures, it should be as small as possible. In an alternative configuration, the hf power supply 6 and socket arrangement 11 canbe located in a fixedstructuresuchasaship, submarine, oil rig etcsuch that the diver can plug the "wand" 9 into the socket arrangement 11 on the structure.

The hf power supply must have a high inherent degree of safety to avoiddangerofelectrical shock to thediver. A.suitablehfpowersupply is described in UK Patent number 2130823. This senses changes inthe load and adjuststhepowersupplyaccordingly, making itparticularlysuitableforuse with the simple inductive coupling of the invention.

Thearrangementofthewiringcircuits4 shown inthefigureshasbeen found to be the roost convenient and effective. Inductance is reduced by wiringthecircuitswithpairedwiresandthearrangementofthefivecircuits eliminatesthe riskofacross-chestelectrical currentshouldawirebreakor some other fault occur. Obviously any suitable safe and effective number and configuration of circuits can be used.

The hfpower supplyconvenientlyoperates at about30 kHz. With an outputof500W itcanprovidesufficientheatingevenatdepthsbelow450mand it only needs dc inputs of about 24V to 36V which can easily be provided by batteries carried onboard a divingbell or submersible aswell asonshipsor surface structures. This eliminates any need for large generators and transformers. However anyhigh frequencypowersupplycanbeused andhigh frequencycurrentcouldbe transmittedunderwater, atahighvoltagelevelto minimiselosses, and thevoltage level canbesteppeddowntoasafelevelfor supply to the suit. There are three main arrangements for the power supply. In the first it is carried by the diver and dc is supplied to the diver. Thediver plugs his suit into the power supply by means of the quick release coupling. This is easy and also allows the option of the power supply being used for other means such as power tools when the suit is not connected to it. Oily small, light cables need be used to provide the power to heat the suit. In thesecondarrangement thepower isprovidedthrough a ixedstructureandthe diver plugs his suit in at a supply point. The coupling between the diver and the power supply is a quick release coupling. The inductive coupling where the "wand" is inserted into a tube containing the primary coils of the power supply is a particularly good form of quick release coupling as the "wand" can easily be pulled out if the need arises.

In the third arrangement thepower supply is suspended on acableand this can be raised and lowered. This, like the first arrangement, is particularly useful for diver decompression routines, buthas the advantage that the diver does not have tocarrytheequipmentwithhim. When thediver is working at depth, and ascending or descending, his rate of work is sufficient to keephimwarmbutduring decompressionprocedureshe ascends to a certain depth, waits there for some minutes, ascends to thenext stationary depth point, waits again and so on. While he is waiting at the stationary point he can get very cold. With this arrangement he canplug himself into the power supply when he is stationary and keep himself warm. The power supply is raised and lowered with the diver and can be used when ever necessary.

The suit thus described canbemadewithaveryhighsafety factorand a low weight of equipment. Its use reduces the bulk of required cables and lower power levels can be used.

Use of the suit is obviouslynot restricted todiving situationsbut can be used wherever similar body heating is required.

Claims (8)

£L__G_£

1. Heating means for a diver comprising: a) a suit (2); b) one or more electrically independent wiring circuits (4) distributed over the suit (2); c) a high frequency power supply (6); and d) a releasable inductive coupling (9,11) to connect the suit wiring circuits (4) to the high frequency power supply (6); theprovisionofhfelectricalcurrenttothewiringcircuits (4) causingheat to be generated in the wires to heat the suit (2).

2. Heatingmeans according to claim1 characterised in thatthe inductive coupling comprises two parts: an outer primary coil arrangement (11,7) connected to the power supply (6); and an inner coaxial secondary coil arrangement (S,8) connectedto thesuit (6), the secondarycbil arrangement (9,8) beingformed soastobe releasablylocated inthecentreoftheprimary coilarrangement (11,7) wherebythesuit (2) canbeconnectedordisconnected from the power supply (6) as required.

3. Heating meε_ns according to claim1 orclaim2 characterised inthatthe hf power supply (6) is carried by the diver.

4. Heating means according claim 1 or claim 2 characterised in that the power supply (6) is situated away from the diver.

5. Heatingmeansaccordingtoanyoneoftheprecedingclaimscharacterised inthatthesuitwiring circuits (4) arewiredandarrangedsoastominimise inductance effects.

6. Heatingmeansaccordingtoanyoneoftheprecedingclaimscharacterised inthatthereare iveindependentwiringcircuits (4) for: leftarmandleft side ofchest (4a); rightarmand right sideofchest (4b); leftleg (4c); right leg (4d); and back (4e).

7. Heatingmeansaccording toanyoneof thepreceding claims characterised in that the safety limits of thewiring and insulation in the suit (2) and the power input are such that there is no danger to the diver if any water leaks into the diving suit (3).

8. Heatingmeansaccording toanyoneoftheprecedingclaimscharacterised in thatheating of differentparts of thebody iscontrolledon thesuit (2) by varying the density of the wiring (4) with greater weighting being given to those areas which require more heat.