21 December 2001

Air suspension system for Househam sprayers

By Mike Williams

AN air suspension system developed originally for trucks is now available as an option for some models in the Househam range of self-propelled sprayers.

It is a system which offers a smoother ride, increased output and reduced maintenance costs, the company claims.

Called Air-Ride, the new suspension is based on rubber air bags made by Firestone and widely used on commercial trucks and other heavy-duty vehicles. With two suspension units at the front of the sprayer and two at the rear, each air bag is linked to a regulator valve which controls the air pressure in the system to adjust the firmness of the ride.

Built in to the system, which has 21cm (8.5in) suspension travel, is an automatic levelling and load compensation action. A rubber buffer built into each air bag reduces the risk of impact damage if an air bag leaks or has been set for insufficient pressure. However, the risk of leaks and other problems is likely to be small, says Househam managing director Rob Willey.

"The air bag suspension has a good reliability record from millions of miles of truck operation," he says. "It is also mechanically simple with little to go wrong."

Househam sprayers have been equipped with a coil spring suspension since 1990, and this will remain the standard system when the Air-Ride option is introduced in January, but Mr Willey thinks the advantages offered by the smoother ride will be a big attraction. One of the benefits is faster travel speed while spraying and for journeys to and from the field.

"This should mean a significant increase in output in many situations," says Mr Willey. "The other benefit we are expecting is less wear and tear on the sprayer because of the reduced vibration. This should mean lower servicing costs, and there is plenty of evidence from truck operators to show that air bags can bring down the cost of vehicle maintenance."

The search for an improved suspension system was prompted by requests from Australia, an important export market for Househam.

Eddie Cunningham, design engineer at Househams headquarters in Leadenham, Lincoln, says Australian farmers prefer to spray at 25 to 30kph and because they do not use wide, low ground pressure tyres to help absorb some of the bounce, sprayers and their operators often have a rough ride.

Air-Ride is available from January next year as an option on 2500 and 3000 litre sprayers. It will later be extended to other models in the Househam range. Price details are not yet available. &#42

Househam Super Sprint sprayer with the new air suspension system.

Suspension detail. The lever linkage ensures ride height – and the suspension travel – is maintained irrespective of loading. Should the load increase and the bag compress, the lever opens a valve to allow air to be pumped in until the pre-set height is regained.