Mind you, when it comes to presenting a conventional and restrained image, Trevor is hardly the best role model. On National Service, he'll tell you, he was thrown out of the Intelligence Corps ("they discovered I was interested in dialectical materialism").
Then in the l950s he became an international backstroke swimmer which led to him earning a living as an exhibition swimmer and diver. Sometimes he did stunts for films - "I used to fall off ships dressed in women's clothing. " And on one memorable occasion he appeared on television swimming in a big tank with TV presenter Austin Mitchell and a killer whale. (Mr Mitchell was so impressed by the killer whale that he left television and become a Labour MP.) Even now Trevor's protestations of the normality of his trade are rather belied by the fact that he lives in what could only be an inventor's house on Eel Pie Island, a legendary place in the River Thames at Richmond. He has a workshop with lots of tools and clockwork motors, and a riverside patio half occupied by an unfinished homemade car.
For some years now, Trevor has a made a living selling easily-installed swimming pools to schools but his urge to make other useful gadgets - to invent - has always run alongside this. In the l980s, for example, he made a one-handed can opener for disabled people. This led to a whole range of other helpful household devices for people with disabilities.
But his "Eureka moment" that all inventors dream about came three years ago. He was watching a television programme about the difficulty of getting information on HIV and Aids to remote communities in Africa. Radios were a useful device, but because of the expense and scarcity of batteries, people had to ration their listening and, not unnaturally, preferred to spend battery time on entertainment rather than health education.
Trevor pondered on this and wondered about alternatives to batteries. Recalling the gramophone of his youth, which used a spring motor rewound with a crank handle, he decided to see if it would be possible to make a wind-up clockwork radio. Within half an hour of the programme's end he had established that the principle was sound - a spring motor, rewound by hand, really would drive a small generator and make a portable radio work.
And in his Eel Pie Island workshop he soon made the first prototype of what is now the Baylis radio. The production version will work for an hour on a one-minute wind and will soon be produced in hundreds of thousands for the developing world.
From workbench to production, though, was a long and difficult road; eventually a City firm became interested and, in turn, attracted a development grant of Pounds 150,000 from the Overseas Development Administration. This partnership of public and private finance made it possible for Trevor to develop the product and make it marketable. Orders from development organisations for thousands of Baylis radios are now on the books, and they will be built, initially, in a new factory employing 150 people in Capetown. The factory is a model for the developing world and employs a high proportion of disabled people.
Last month Trevor's initiative took him to South Africa where the BBC began to film his remarkable story for a QED documentary to be shown in August. Meanwhile, he is turning his attention to the forthcoming generation of inventors. He is already deeply involved with schools - his business for many years has been the manufacture and supply of Shotline portable swimming pools to schools, and with his inventor's hat on he has been an adjudicator for the Engineering Council's Young Engineers for Britain competition.
The more he sees of schools and reflects on his own experience, the more he wants to see an inventor-friendly curriculum and a positive image for the whole idea of invention. In common with some other engineers, for example, he feels that children spend too much time on computers. "The hands-on experience is what's important - taking the back off a clock; learning to sew and knit".
Reinforcing this he points out that he still carries a slide rule rather than a calculator, "so I don't have to rely on those poxy batteries". (Incidentally, Trevor's views suddenly made sense when I tried in vain to explain his radio to a 13-year-old. I carry in my fingers the feel of winding up a clockwork toy. Today's youngsters, brought up on electronic watches and playthings, start out with no concept at all of what a spring motor is, or what the word "clockwork", so much a part of the language, actually means.) Persuading education to recognise invention, though, is only part of Trevor's mission. Perhaps more important to him is his desire to ensure a fair deal for young people who have bright ideas. "There are people who live off the backs of inventors - they advertise in the classifieds for ideas and inventions and take money from you. Then when nothing happens they tell you there was never any guarantee of success."
There is plenty of evidence to show that Trevor's thoughts are timely. National curriculum technology is producing a stream of new ideas and products from both primary and secondary classrooms, and the various schemes which promote school-industry links are bearing some exciting fruit.
That school-based ideas can be both educationally excellent and potentially commercial is borne out by the list of more than a dozen projects which the Standing Conference on Schools' Science and Technology (SCSST) uses in its publicity leaflets. A typical example is described thus: "Students from Plymstock School, Devon, developed a water control valve for South West Water which will be manufactured in large quantities." This valve, explained Plymstock's head of technology, Robert Ingram, is "a revolutionary idea. It works with no mechanical intrusion into the tube space".
So far, though, the valve still awaits the company's decision on commercial development. Meanwhile, the interests of the school and the students are protected by a patent application, and Robert Ingram denies there is any disappointment at the lack of progress. "I think had we time to pursue it alongside the company then there might be some future in it."
The point is that his priorities as an educator are different. "We have done a number of projects with large companies, the idea being to give sixth-form students the experience of working with industry on what is degree level project work. Once this has been achieved, the year comes round and off we go again."
The experience of Ben Barker, art, design and technology co-ordinator at King Edward VII School in Sheffield, is much the same. King Edward's has won numerous design and technology awards, including The TESYoung Engineers Teachers award in 1993, raising only marginal commercial interest. "We have a perfect example. Two girls designed a beach bag that's secure against theft. If someone picks it up a loud siren goes off."
Potential customers who know about the level of theft on surfing beaches from Perth to California have expressed lots of interest, and the device is patented in the names of the pupils. "We're within a millimetre of getting there, but I guess at the end of the day people don't have confidence in what the kids have done. Perhaps business and industry feel they know what's best and want to have control over it."
Like Robert Ingram, Mr Barker is also conscious of the educational imperative. "I teach almost 400 pupils in a week. I can't really spend a whole lot of time on a project with one or two."
What is needed, he feels, is a panel of retired industrialists who could spend time promoting school-industry projects. "The country must be full of people like that."
Pamela Bowen, national director of the SCSST's Young Engineers, which promotes school-industry projects, is well aware of the need for just this sort of body which could advise both on protection and promotion. "It's something that has been talked about, and I have to say there are moves afoot at this moment. We are very aware of it."
For his part, Trevor Baylis is clear about what is required - a Royal Academy of Invention, no less. It would raise the status of invention and affirm it as a creative, as well as a technical process. Senior members would pilot inventors through the very early stages, which are not only dangerous in terms of exposure to theft and ill-informed advice, but can be expensive in patent and legal fees. (King Edward VII School is faced with considerable costs if it goes on past the preliminary stage with the beach bag patent.) "There would be an initial, very sensitive sifting out of those dreams that are against the basic laws of physics. Then, in complete confidence, they could arrange for drawings to be made, or a prototype to be built."
Trevor is in no doubt about who would form the voluntary backbone of the academy. "Successful inventors who don't have to worry any more and have been through the mill." (People like himself, that is!) They would give the good advice that people need about securing their own intellectual property.
In addition there should be "professional folk to advise on commercial and legal matters". And a figurehead - "The Prince of Wales would do very well. "
Trevor envisages that the academy would award memberships and fellowships, recognising, perhaps, the best work that goes on in schools. "They may not make a lot of money, but they could have a handshake from HRH and proper recognition."
His enthusiasm is infectious, and you are amused until you remember that this is no single-issue eccentric talking. This is someone who one evening had a brilliantly simple idea which is on the brink of making him some very serious money. The thought makes his intensity a little moving - he is particularly eloquent on the notion that good ideas can come from anyone, regardless of age, background or level of education. "As soon as we come into this world we start having peculiar thoughts. These thoughts are common to us all, and they're called ideas."
* Details of Young Engineers, including TES Teachers award, from Young Engineers National Office, Surrey Technology Centre, Occam Road, Surrey Research Park, Guildford, Surrey GU2 5YG * The Engineering Council runs schemes which link schools with working engineers (Neighbourhood Engineers, Young Engineers for Britain) for the mutual development of projects.The Engineering Council, 10 Maltravers Street, London. WC2R 3ER * The Comino FoundationQuo-Tec Award Scheme. Set up by Demetrius Comino, the inventor of Dexion modular construction components, with technology consultants Quo-Tec, makes awards of up to Pounds 5,000 each year to "projects which have demonstrated significant progress towards becoming a successful commercial product". Up to now these have gone to finalists in the Engineering Council's Young Engineer for Britain scheme. Details are included in Quo-Tec's Instruction Kit for Young Entrepreneurs available on request from Quo-Tec Ltd, The Dray House, the Maltings School Lane, Amersham, Bucks HP7 0ET.
* Rotary International's Young Inventor of the Year competition is organised by Rotary clubs throughout Britain and is in its third year. Entry forms are available from local clubs. The final is held in November with a Pounds 10,000 first prize; all entries receive participation certificates.