My late uncle, John Chambers, joined Harry Ferguson‘s team in Belfast as a 22-year-old draftsman and rose to become chief engineer.

He told me many fascinating stories of his time with Mr Ferguson – he only ever called him “Mr”. This is the tale of the birth of the linchpin.

My uncle accompanied Mr Ferguson to Detroit to assist in selling the Ferguson System to Henry Ford. That production line inventor was regarded as the only person who could manufacture enough tractors to satisfy global demand for the patented revolutionary hydraulic depth control system.

While Mr Ferguson and Mr Ford were in private discussion, Uncle John was walking around the car assembly plant. As he strolled he was fiddling with his key ring, taking the key on and off, and he noticed that when it was just about to depart from the ring it tended to torque over.

With key ring in hand John went over to the small blacksmith’s shop within the factory, where every employee of the Ford Motor Company was encouraged to take new inventive ideas.

He explained his concept for a securing device, to replace a nut and bolt, to the foreman who immediately understood, and within the hour the world’s first linchpin was manufactured.

Never a day goes by without me using this simple labour-saving device, and I enjoy sharing the story of its creation.

Mistake of the month: Offered to convince Northern Ireland’s potato growers and packers to contribute to a “voluntary” levy towards maintaining and improving the NI Potato Stakeholders Forum.

This is a relatively new organisation, which has potential to bring big benefits to the whole industry. It will earn me some flak, but I quite enjoy that.