will operate during the operation of the chopping knives the grain sweeping beam 8 remains in its upper inoperative position due to the latched condition when sweeping out is to be commenced then the carrying arm 6 is again raised and namely into a position which is higher located than is required for the latching pursuant to fig4 b upon a further rising the spacing between the grain sweeping beam 8 and the carrying arm reduces still more so that the bolt 29 can then in accordance with fig4 c travel along the sliding surface 40 of the releasing latch 36 as a result thereof the latching lever 30 is pivoted into the position shown in fig4 c so that the bolt 29 travels about the releasing latch 40 the weight of the latching lever 30 itself then presses the bolt behind the projection on the releasing latch 40 when the carrying arm 6 has now descended then the bolt 29 presses the releasing latch 36 into the pivoted position which is illustrated in fig4 d in this position the latching member 35 is bypassed such that the bolt 29 will be conducted about the latching member 35 during the descending movement thereby the grain sweeping beam 8 is unlatched and can be lowered into the position shown in fig1 in.