Folding collection platforms, advanced technology

Innovation in the folding platforms sector is geared to meet the users' main needs, such as reducing dead times, increasing operational capacity, especially in case of unfavourable harvest conditions, and adaptability to different crops. Before joining a head not recommended by the manufacturer of the machine, it is advisable to carry out adequate verifications and check, for example, that after the coupling, the requirements for road driving of the machine are still complied with

The different types of harvester heads (or cutting platforms) for combine harvesters are very different one from another, but all of them separate the drums, or their useful parts, and then direct the crop to the part in the machine that will operate the separation and cleaning (threshing). The different types of platforms are always hinged to their carrier frame, allowing them to be adjusted in height, that once was done manually, but today is almost always done automatically using special sensors and actuators that often also allow to set some adjusting on the transversal plane. The Heads used in the Italian territory have average working widths lower than those employed elsewhere, or in any case wherever the size of the fields is larger than ours. On the market, there are heads with working widths ranging from 3 to 12 meters in average, but often, in Italy, it is preferred to use, even on larger and powerful machines, heads of about 7-8 m using, if necessary, higher forward speed in the field than those commonly used abroad to offset the smaller dimension of the head, and to ensure, however, the right product flow to the internal organs of the combine harvester. Current research is aimed at meeting the main needs of users, in most cases, contractors, and are essentially the reduction of dead times, the increase in operational capacity, especially in case of unfavourable collection conditions (e.g lodged products), and the ability to adapt to different crops. As the reduction of dead times, evolution is increasingly tensed to reduce the connection and disconnection times between the head and the combine harvester, to facilitate road transfers, which in the case of traditional heads require the head to be disconnected from the rest of the body of the machine, and its side-facing positioning to the direction of travel, on a dedicated trolley. Despite the considerable decrease of time for connecting and disconnecting the fixed heads, which has made been possible more recently by the introduction of hydraulic units with “quick-coupling”, it should be noted that, in any case, with this modern solution the release times from the lift channel, the link on the rear hook and the following hanging up to the elevator, take, at least 15-20 minutes. It’s a big step forward over a decade ago, when it was twice the time, but it is still much higher than simply folding for road transport, which can be done with folding heads even in less than a minute. Clearly, it is no small difference for those who are forced to do this many times on the same day, therefore, it is not a coincidence that in our country, as the average size of the fields is small, folding heads receive much more attention than, for example, in France, Germany or in the United States. In some cases, folding heads are also offered as optional equipment directly by the combine harvesters manufacturers, but more often they are specifically post-market tailor made by specialized producers who, in some cases, offer the same product even “branded”, with the producers colors and logos, and that will then market them directly. There are cases in which these producers can offer products that, even from the point of view of the equipment, succeed in overcoming the offers made directly by the combine harvester manufacturers. At present, there are folding heads for cereal straw and with special arrangements to better suit crops such as rapeseed and soybeans, furthermore, folding heads for harvesting maize and/or sunflower have long been available. As far as the solutions that allow the folding of the head are concerned, those for straw cereals use four different mechanisms: the first involves the forward movement of the head and then the 90° rotation of the two sections on the horizontal plane; the second mechanism creates a parallel overlap of the two semi bars by rotating 180° one section on the other; the third, involves a 180° tilt of one section on the other, or of the two side sections with respect to the central one. The latest, and most recent one, requires a 180° folding of the side cut semi bars, and the use of a telescopic central reel. It is, in this  case, the only solution that allows to produce folding cutting heads with widths of over 10 meters, but that can suit the 3.2-meter silhouette for road transport. The folding heads for corn and sunflower have usually a fixed center section with two side sections folding at 180°. In all cases, for the handling, double action hydraulic jacks are provided. From the practical and operative point of view, the different solutions that allow the heads to fold over themselves have no significant differences, it is clear that every technical choice entails, as always, both advantages and disadvantages, and that a folding bar, compared to a monolithic of the same size will still have a greater amount of “delicate” joints and parts that require periodic maintenance and prop er functionality and holding checks in order to avoid the risk of heads breaking down right in the middle of harvesting. In any case, prior to coupling a head which is not proposed by the manufacturer of the machine, it is necessary to make the necessary checks, to verify that after the coupling the requirements for road driving of the machine are still met. It is necessary to verify that, both from the point of view of the size (gauges) and from the correct weight distribution, the coupling does not make any changes as compared to what is stated on the machine’s booklet, and as foreseen by the Code of the road. An ever-present problem that comes from traveling on the road with folding bars, is undoubtedly, the decreased frontal visibility of the area closer to the machine, which, of course, is hampered by the presence of the bar, which once folded inevitably increases the vertical intrusion. An additional problem, often underestimated, is given by the need to check that at least 20% of the total mass weighs on the axle of the steering system (in this case it is usually the rear axle). It is precisely on that point that inconsistencies often occur, which in most cases can, however, solved by appropriately weight down the machine. In order to avoid creating hazardous situations, in choosing a folding head it is also important to consider that its displacement in the folding phase must take place without causing excessive imbalances in the combine harvester, especially if these folds occur on not flat lands.