Poor police dogs had been hurting their paws for years as they tramped through broken glass in pursuit of villians.

The hundreds, if not thousands, of pounds that had been invested in training them was wasted as injuries put dogs out of commission.

His paws are safe

But now their delicate feet are safe from harm all thanks to Mr Buchanan's invention.

If his story had been fiction, the following chapters would have read along the lines of him setting his ingenious plans down on paper, getting the product made, then watching the orders - not to mention the cash - come flooding in.

But the reality for Britain's lone inventors is that they must have a fair amount of money to invest in their idea, a certain amount of business accumen, and the ability to wade through oceans of paperwork.

James Dyson's biography chronicles his far-from-overnight success. The idea that sparked a cleaning revolution came to him in 1978 - but he didn't clear his overdraft until 1994, and was at one point £1m in debt.

The quality inventors cannot possibly hope to survive without is the tenacity of at least 1,000 people.

"Having the idea is the really simple bit," says editor of Inventors World, David Wardell, "What people often don't realise is that inventing is not a route to getting rich quick.

James Dyson: A model of tenacity

"Inventors have to protect their intellectual property rights, get their idea patented, decide whether to manufacture their product themselves or to seek out a manufacturer to do it under licence for them.

"And just because an idea is patented in this country does not mean that it is patented in another."

Even before applying for a patent, inventors have to evaluate the worth of their idea - essentially, if it will have a market and if they will have the resources to follow the project through.

Patents are effectively a state-endorsed monopoly of an idea, forbidding anyone else from making the product for 20 years.

They are the only way of stopping someone else copying your fab idea - copyright protects aesthetic, rather than functional inventions.

But getting hold of one is a long, arduous and relatively costly process.

The Institute of Patentees and Inventors - which represents lone inventors in the UK - says that failing to seek legal advice is a grave mistake. The process, with legal help, costs anything from £1,500 - £2,000.

Chairman Paul Ambridge said: "You fill in your patent application form from the patent office, then you take it to a patent agent or a patent attorney and give them the application form, because almost certainly you will not have filled it in as you should have done. The wording of it, for example, is very important.

"Then the patent office will investigate whether the idea is new, and if it meets all other criteria.

"If after checking they are satisfied that a product is entitled to a patent, they will publish details of it, so that the application can be contested." From start to finish, the whole process usually takes four to six years. And that is just getting one in the UK.

The people at the patent office vigorously research the world's 40 million existing patents to note if a proposed idea is new, not obvious and works.

Mr Wardell recalls one patent application - for a doorbell for dogs - that failed because the investigator had seen a similar device being used by Gnasher in his daughter's copy of the Beano.

"The comic was considered as prior art, and therefore the idea did not belong to him," said Mr Wardell.

For ideas that do make the patenting grade, the usual route is then for inventors to get commercial backing - and therein lies another hoast of obstacles.

British manufacturers, it appears to lone inventors, would rather spend millions of pounds buying up established businesses than investing considerably less in an untested idea.

"It can be so frustrating," said Mr Buchanan, whose latest project is a new style of golf putter.

"As a nation we produce such a wealth of fantastic ideas - but most of them go overseas, because we do not have the attitude that supports lateral thinking.

"I can phone an American company and get straight through to the managing director or the head of research and development, and they will listen to what you have to say.

Gnasher had a dog's doorbell first

"Here, people simply regard lone inventors as being nut cases locked away in sheds, tinkering about."

And that's even before inventors are forced into the courts to defend their precious innovations from people who try to pinch them.

Sir Christopher Cockerell, the inventor of the Hovercraft who died this week, often criticized the lack of support the UK offers its many inventors.

Mr Armitage said that the Japanese equivalent of the Department of Trade and Industry, MITI, has reported that 55% of the world's inventions over the past century have come from British ideas - and that billions of pounds are lost to the UK plc coffers every year as ideas are taken overseas.

Mr Buchanan's new putter

While grants exist to support business plans, there is still no form of financial assistance directly available to inventors to develop ideas, although it is hoped that improvements are in the pipeline.

The IPI has campaigned - to no avail - for a scheme to help innovators with government loans of £500 - £5,000.

Yet still inventions continue to emerge - with the patent office receiving year on year something in the order of 27,000 applications. On average, only 2% of those ideas ever make it to the market place.

Mr Armitage said: "I am chairman of the Institute of Patentees and Inventors, and I would advise anyone, if they have a good idea, and about £3,000 - then take the money and buy lottery tickets with it.