31 August 2001

Improving intake capacity

By Andy Collings

YOU can have the largest capacity combine in the world but, if the volume of crop cannot be put through it to exploit this capacity, then time and money can be wasted.

Engineers, quite naturally, have concentrated on improving grain separation systems and not, it seems, in developing the header to improve intake capacity and crop presentation. There are, of course, a few notable exceptions – MFs Powerflow table not being the least of them, and there is also the Claas extending knife system.

A company which majors in producing a combine header claimed to enable all crop-types to flow evenly into the combine is Biso Schrattenecker, which is located in Austria.

Now imported by Saffron Walden-based Abrey & Son, the Biso-VX-Crop Ranger is available in 4.5m, 5.5m, 6.5m, 7.5m and 9m working widths and is designed to fit certain New Holland and John Deere combine models.

Key to the system is a knife which can be moved hydraulically 10cm (4in) closer to the table auger than conventional fixed settings and 58cm (23in) away – a total movement of 68cm (27in).

This, says the company, allows the operator to make changes on the move to accommodate short straw (knife close to the auger) or tall oilseed rape (knife away from the auger) or, for that matter any distance in between.

In operation, the effect can be quite dramatic. Combining in short wheat, positioning the knife close in allowed the crop direct access to the auger with out any bunching. Moving it out saw the crop start to bunch with the result that uneven wads of crop were presented to the drum. It meant that the combine had to be slowed and outputs fell.

Biso says that the header allows the full potential of the combine to be used and claims that output could be as much as 20% higher in some crops.

The header uses the combines own hydraulic supply to power the reel height and fore and aft movement but has an internal hydraulic system for reel drive, knife extension and vertical side knife operation. A 30-litre oil supply is retained in a section of the headers box section main frame.

Electronically operated solenoid valves are activated from the cab to control reel speed, knife extension and side knife operation. A neat touch is the ability to fold the vertical knives horizontally when not required, so re-setting the header to cope with say, barley after oilseed rape takes only a matter of minutes.

Drive to the auger and knife wobble box is mechanical – the latter is driven by a V-belt with a self tensioning pulley system to allow drive to continue as the knife position is altered.

Those who might be concerned that, with such adjustments available for knife and reel position, it is possible to put the reel tines into the knives need not be. A guide rail ensures that this cannot happen.

For automatic height control the Biso header employs skid sensors linked into the combines existing system – as does the reel speed/ground speed synchronisation system.

Opting for a Biso header adds about another £8000 on to the price of a combine – a premium Abrey & Son believes can be justified by the greater output potential. The company aims to place 15 of them for next years harvest. &#42