19 November 2018, 15:01
The SDF Group's continuous and considerable investments in research and development have enabled it to offer a preview at EIMA of the Frutteto CVT ActiveSteer, the first specialist tractor equipped with 4WS technology, which introduces four-wheel steering to vineyards and orchards for the further benefit of safety and productivity.
Having been the first company to mass-produce a four-wheel-drive agricultural tractor with the SAME DT 25 in 1952, and to produce a four-wheel-drive tractor with a central drive shaft in 1965, SAME's specialist tractors now introduce a totally new technology to this sector. Indeed, until now four-wheel steering in agriculture has been confined to telescopic loaders and, in rare cases, also to open field agricultural tractors. However, SAME is now offering its first four-wheel steering system specifically designed to increase performance and safety in tight spaces such as vineyards and orchards where specialist tractors require maximum manoeuvrability. In addition, confirming the need for the utmost compactness, it has introduced this technology while keeping the track and wheelbase values the same as for traditional rear axle versions.
As well as increasing manoeuvrability, four-wheel steering technology offers greater safety than articulated tractor or axle systems, which to obtain a higher steering angle are further forward than is traditional, in that it doesn’t require a larger wheelbase and nor does it cause shifts in the machine’s centre of gravity. Thanks to the new rear axle, the rear wheels can also now achieve an angle of plus or minus 20°, and their position is controlled by an electronic control unit with three different driver controlled operating modes. This allows the driver to select:
the movement of the rear wheels in relation to the front ones, which drastically reduces the turning radius, but without ever adversely affecting the machine’s stability;
crab mode, useful for example when contour ploughing along the lines of a slope, but also for handling operations with forklifts in confined spaces - delayed mode, with which steering is in any case proportional to that of the front wheels, but with a slight delay. Indeed, this function is very useful for driving with towed trailers. Thanks to this feature they will no longer tighten the turning radius with respect to the tractor in front of them.
In addition to these three automated control modes, the steering angle of the rear wheels can be adjusted manually, and also locked at will to compensate for slipping downstream of the sloping rear axle or locked in a central position for road transport. The following is an example of the possible reductions in turning circle that can be achieved with SAME Frutteto CVT ActiveSteer compared to vehicles only equipped with the Active Drive front axle.