In the early days of self-propelled crop sprayers, operators seemed to be forever changing the track widths to suit a variety of crops. As time moved on there seemed to be an agreement in the industry that all this wasted time changing track widths just had to stop. 72” became the standard UK tramline width, but with a few exceptions.
It was for this reason that SAM engineers designed a new sliding axle in 1998 that was easier to adjust manually or could be fitted with hydraulic assistance; this axle was capable of moving from 72” to 84” in 4” increments. This design was destined for a long production life until, a couple of years ago when a major potato machine manufacturer realised that by harvesting three rows of potatoes instead of two, would speed up harvesting by 50%, and thus started to redesign their machinery to suit this new idea. As a crop sprayer spends more time in a potato field than any other machine, SAM saw the need to provide axle widths to suit. 3 x 36” rows = 108” (or 2.7m for 0.9m rows) makes for a very wide machine on a road and would prohibit the use of some very narrow lanes.
SAM is now offering a wide axle option, on all Horizon models. This axle will adjust from 72” (1.8m) to a maximum of 108” (2.74m) without the driver leaving the seat so the machine can arrive at the field on a road friendly track width and then adjust to a very wide 3 row setting in a matter of seconds. The axle, with mechanically locked sliding legs, is adjusted from the cab by pre-setting the required track width, in metric or imperial units by means of a rotary dial on a dedicated screen. The machine is then driven forward at a slow speed. The axles will unlock, move to the new trackwidth and relock. Front and rear axles can be set independently in order to “spread the load”.
The complete system is “fail safe”. SAM believes this is the ONLY axle with this width capability which is completely road legal as it meets all the requirements of the European Directive 70/311/EEC and, in particular, Section 2.2.2.
During normal working, the axles are clamped by hydraulic Cam Locks powered from the vehicle suspension system. This means the clamping force is proportional to the suspension movement: Rough ground = Big suspension movements = High clamping force.
Non-moving linear transducers are fitted into all eight axle rams. They tell the control box the position of each ram to an accuracy of 0.1mm via a dedicated CAN BUS network.
All rams are also locked hydraulically with twin P.O. check valves.
In the interest of safety, the oil supply is diverted away from the dedicated proportional axle valve bank when axle adjustment is not being used.
In order to adjust the axles track, the machine must be in its slowest drive mode – full displacement on both axles, and be driven between 3 – 9 Km/h. This ensures that minimum stress is put on the axles during adjustment.
European Directive 70/311/EEC and in particular, section 2.2.2. Which states:- It must be possible to steer the vehicle in the event of the total or partial failure of the hydraulic, pneumatic or electrical components of the steering gear.
Horizon 4000 ‘E’ - extra wide axle model
10.5 tonnes (36m boom)
8m @ 72in track (approx.)
9m @ 108in track (approx.)
Deutz 6 cylinder 158 Kw (212hp) Tier 4 Final (AdBlue)