thread direction of the threaded rod is opposite to that of the other the distance between the hinge points 22 and 23 can be adjusted by turning the bushing 35 the result is a change in the inclination angle of the housing 6 and therefore of the angle at which the crop is being cut an adjustment of the length of the support arm 16 may also be necessary when rollers 8 are used with different dimensions with a change in height of the header 1 the resulting angular displacement of the chopper 5 does not necessarily have to be equal to 0 a deviation up to about 5 u00b0 is tolerable without significant loss of efficiency of the chopper such a small increase in the angle may even be advantageous in the lowest range of the header 1 this low header height is used in laid crop when the stems can no longer be harvested efficiently the chopper is then used to shred the plant completely so that it can be ploughed in efficiently fig4 shows a top view of the front part of a combine harvester according to the invention represented are the header 1 the feeder system 3 and the chopper 5 the left coupling system 10 is also shown in this embodiment there is one such system symmetrically on either side of the feeder system the connection of the upright support beam 11 with the header 1 may be constructed in different ways in the embodiment shown the support beam can be attached via a hook 40 to a transverse pin 41 at the top of.