28 April 1995

Automatic system improves inflation

AN automatic inflation system developed by a Yorkshire garage equipment company is designed to eliminate the dangers involved in fitting large tractor tyres.

The AVS Autofil is a microprocessor-based controller which regulates the delivery of compressed air to the tyre, monitors the pressure during the inflation cycle and prevents the pre-set maximum pressure being exceeded.

"Fitting and inflating tyres can be a dangerous process when using an air supply capable of exceeding a tyres maximum pressure limit," says David Francis of DMF (Wakefield). "This system removes this danger by allowing the fitter to set a pressure ceiling. It can also make the process quicker and easier."

High initial flow

Michelins Stoke-on-Trent-based technical group helped develop the system, particularly with the requirements of tubeless tyres in mind. These need a high initial flow of air to provide sufficient volume to lift the beads on to the rim, then a high inflation pressure of about 2.5 bar (36psi) to seat the beads properly, before air is let out to achieve the required operating pressure.

Allowing too much air to be pumped in – through negligence or ignorance – can cause tyre structure damage or a sudden rupture, with dangerous and possibly fatal results for the fitter.

The current model, selling for £1200, is mains electricity powered, but DMF is currently working on a 12V battery-powered version for mobile use.

Dangers of over inflation when fitting large tractor tyres are claimed to be eliminated with the AVS Autofill. Current model price is £1200.