Struggling in the mud under a centre pivot, with a jack balancing on wooden blocks, is now a thing of the past, thanks to a grain farmer’s smart idea. Johan van der Merwe did the reporting.
Flat tyres and broken gearboxes on centre pivots can now be safely repaired in an instant thanks to a clever device invented by Mr Vaughan Phillips of Newcastle, in Northern KwaZulu-Natal.
Phillips is the manager of approximately 1000 ha of maize and soya enterprises on Dumfirmline, in KwaZulu-Natal in South Africa.
“In the dry season, you really have to be on your toes to keep all these centre pivots on the go. In addition, the wooden blocks and jack underneath the A-frame pivot are unstable and extremely dangerous,” says Phillips. “And once the tyre or gearbox has been repaired after hours of struggling to get the centre pivot working again, there’s usually major damage as plants around the repair site have been trampled.
“This device makes maintenance of, and repairs to, any centre pivot quick, cheap and safe, with minimal damage to plants,” says Phillips. This bright idea came to him in 2012 when centre pivot maintenance began to overwhelm him. “One gearbox after another was failing and a lot of flat tyres also needed repairing. Accidents happen quickly when you are rushed.”
‘One gearbox after another was failing and a lot of flat tyres also needed repairing.’
The centre pivot repair device only has two legs because the A-frame of the centre pivot only needs to be lifted on one side to change a tyre or gearbox. “The centre pivot tyre that stays on the ground can carry enough of the weight to prevent the device from falling backwards or forwards,” explains Phillips.
Each of the 2.5m-long legs, which are 4mm thick and 50mm in diameter, are placed inside a 60mm pipe (or over a 40mm pipe) on a round anchor plate which is 6mm thick and 380mm in diameter.
The angle at which the two legs are mounted can vary, but Phillips estimates that anything between 45 degrees and 60 degrees should allow for enough workspace under the centre pivot repair device. The anchor plates are anchored into the ground with three 22mm steel bolts (about 150mm long) at a 90-degree angle. According to Phillips, these bolts could be longer for sandy soil conditions.
The two poles are joined at the top with a triangular frame made up of two 60mm steel pipes. The lever block is hooked onto this. “As soon as the weight of the centre pivot is placed on the lever block, the two legs of the repair device push the anchor plate bolts deeper in the ground which ensures the stability of the design. The lever block also makes it easier and safer to adjust the height for working on the centre pivot axle or wheel hub,” explains Phillips.
The design is simple and can also be used on the lands for changing flat tyres on larger trailers with loads. The materials cost Phillips less than R1000 (K730), without the lever block. The labour to build the implement is minimal, and basically requires no maintenance.
ENQUIRIES: Mr Vaughan Phillips, email: firstname.lastname@example.org