Appliance for removing the wrapping from bales of agricultural harvested crop

#1. Field of the Invention

#The invention relates to an appliance for removing the wrapping from bales of agricultural harvested crop that includes at least one cutting device for slitting or cutting the wrapping and an element for stripping off the cut wrapping.

#2. Description of the Prior Art

#The drawings show:

#FIG. 1. a perspective view of a first embodiment of an appliance for removal of a film wrapping of a round bale;

#FIG. 2. a plan view of the knife and, the round bale at the beginning of separation of the wrapping along three sides of the bale;

#An appliance for removing a round bale wrapping according to the present invention which is shown in FIGS. 1-3, includes a frame 1 carrying two spaced from each other, support rollers 2, a rotatable arm 4 with a knife 5, which rotates about a vertical axis 3, and a rotatable member 6 arranged parallel to the support rollers 2. A cylindrical round bale 8, which is wrapped around with a film material 7, is supported on the support rollers 2. The reference numeral 9 shows a circular trajectory which is described by the rotatable arm 4, together with the knife 5, for cutting the bale wrapping 7. The radius of the rotatable arm 4 and the height of the knife 5 are to so selected, with respect to the support rollers 2, that the rotatable arm 4 can freely circle the bale 8 approximately in its horizontal central plane.

#In order to be adapted to different bale diameters, the height of the knife 5, relative to the support rollers 2 and the radius of the rotatable arm 4, are adjusted with slidable guide elements 10 and 11 which can be, locked in predetermined positions. The control of the trajectory, i.e., the initial and end positions 12 and 13, of the rotatable arm 4 can be effected with an arranged above the support 14 of the rotatable arm 4, disc 15 having a predetermined hole pattern and equipped with two sensors 16 and 17. The disc 15 cooperates with the rotatable arm 4 during the rotation of the arm 4, indicating the arm positions.

#The knife 5 has a triangular shape and pivots about an axis 18 extending parallel to the rotational axis 3 of the arm 4. The knife 5 is supported on a bracket 19 secured at the lower end of the arm 4. In an operational position 20 of the knife 5, a tension spring 21, which is secured, at one of its ends, to the knife 5 and, at another of its ends, to the bracket 19, biases a cutting edge 22 of the knife 5, which is formed by a cathetus of the knife-forming triangle, against the wrapping film 7 at an angle of less than 90°. Upon rotation of the arm 4 in a direction, which is indicated by arrow 23, the film 7 is draw cut through. It is important that during the entire rotation of the arm 4, a constant or, at critical, points, a higher than constant, cutting force is applied by the knife 5 to the film 7 so that the film 7, is perfectly separated also at the corners, end surfaces, and at the front side of the round bale 8. The mechanical control of the knife 5 can be effected by selecting lever arm ratios and/or points at which the tension spring 19 is connected with the knife 5. The appliance can also include a hydraulic cylinder in combination with a hydraulic accumulator (not shown) which would permit to adapt the knife position to the bale profile. Pivoting of the knife 5 and retaining it in the non-operatinal position 24, which is shown in FIG. 2 with dash lines, can be effected with a hydraulic cylinder or a like device.