horizontal mid line 8 39 of that portion of the outlet duct 8 that passes through the supporting device 7 the detaching device 4 may be rotated relative to the tower 2 about the axis 8 39 in either direction so that the detaching device 4 together with detaching opening rolls 5 6 may be brought into a desired predetermined oblique position relative to the fiber bale series 3 by virtue of this arrangement the fiber bale series 3 may be worked on by means of the bale opener 1 along a plane which is inclined to the horizontal at a predetermined angle by virtue of the angularly adjustable detaching device 4 it is possible to continuously perform a fiber tuft detaching operation on the fiber bale series 3 by continuously adding full height fiber bales to the left of the bale series 3 as the bales are being gradually consumed by the detaching device 4 on the right as viewed in fig1 a through 1e for this purpose the fiber bale series 3 is supported on serially arranged conveyor belts 10 11 which feed the fiber bale series 3 in the direction of the arrows g and i relative to the travelling path of the detaching device 4 the fiber bales series 3 is composed of a subseries 3a formed of fiber bales supported on the conveyor belt 10 and a subseries 3b formed of fiber bales supported on the conveyor belt 11 fig1 a 1b and 1c show the run in phase during which the oblique surface 3 iii fig1 c for normal operation is gradually formed from the horizontal surface 3 i fig1 a during the run in phase the fiber bale series 3 is stationary on the conveyor belts.