A grandfather invented a modern plug and socket to help his arthritic mother, and is now trying to market it, so she can use it.

William Dolman came up with the 'Dolman Cobra' after watching his mother Eileen, 90, struggle to pull a normal plug out of the wall because of her arthritis.

His invention was selected as one of the winners at a Design Council competition in London.

But it's not yet a product for sale on the market, so neither his mother nor anyone else can benefit from it.

Mr Dolman, 63, who works three days a week for CTM Harpley Engineering, said: 'It helps people with certain medical problems live more independently.

'I've spent about £40,000 on patenting it. The current plug and socket specification is more than 60 years old, and wasn't designed for ease of use or complete safety.

'My plug and socket works like a petrol nozzle – it guides itself in and it only takes a limited push to engage the plug – less than one third of that for a normal plug.

'Taking the plug out is also very easy and can be done with one finger. The plug is very safe – a strong pull on the cord disengages it, and the socket switches itself off when the plug is taken out.'

As part of his competition prize, he received two days of mentoring on how to market the invention, and experts will visit his home in Westgate Street, Shouldham, near Downham Market, later this week, to help put a business plan together.

Mr Dolman invented a lithographic plate progresser, while working for a firm in Thetford, which is on sale in the US.

See how it works here - www.dolmancobra.com/

Have you invented something revolutionary? Email david.bale2@archant.co.uk