It is said the simplest ideas are often the most effective and if the roots of a fire safety device, designed and made in Brighton, are traced they will lead to a daisy.

The idea for Dorgard came to Neil Purssey after he saw a toy that reacted to sound.

Chris Badenhorst, managing director of Fireco, said it was this dancing daisy that inspired his colleague, Neil, to invent the device.

He said: "Neil worked in the interior design business and the sector was going through a slowdown so he was looking for a product that would beat the recession.

"He had a brain-storming session with a few friends and thought if it was possible to make money from a dancing daisy, then it must be feasible to use the same technology to make something practical."

Mr Purssey went back to his office and saw a fire door held open with a wedge. He thought if it was possible to make a daisy that responded to music then it should be possible to make a door wedge that responded to the sound of a fire alarm.

Mr Badenhorst said: "Within a couple of days Neil had a working prototype."

The Dorgard has been refined and developed to lift a rubber stopper and allow the fire door to swing shut at the sound of the fire alarm.

Most new buildings have a built-in automatic system but there are an estimated 55 million fire doors in the UK the device could be fitted to.

According to Mr Badenhorst, the design and development was the easy part of the operation.

He said: "The hard part was to to get funding, find a marketplace, get the product manufactured and accepted by fire services and convince the owners of buildings it was safe and reliable.

"Having the product tested took a lot of time and establishing what safety standards are applicable was also a long process. We now have patents in Europe and America.

"One of the biggest problems was finding a set of guidelines that suited all the different fire authorities. There are 52 authorities with their own opinions on how the rules should be interpreted.

"One authority may ask a business to carry out a full risk assessment and then fit a Dorgard and another will tell the firm to address a list of 23 points and then talk again.

"We get very frustrated. We are not fighting regulations, we are fighting opinions so we appointed an ex-assistant fire master from Scotland to help us."

Production started in 1994 and by the end of the first year, the firm had sold 1,500 products. Now the company is selling more than 1,700 every month. By this time next year, bosses expect to be up to 4,000 a month.

Dorgard is now accepted and approved by 85 per cent of the fire authorities in the UK.

Fireco said the care industry, with, would particularly benefit from the product.

Mr Badenhorst said: "Wheelchair users need to get past fire doors and if they could stay open, life would be a lot easier for residents and staff."

Previously, the manufacturing was done by another company but it was brought in-house to give the firm more control.

This had brought delivery periods down from 28 to two days.