Resilient arrangement in a ring roller allowing rings to adapt to ground irregularities
The present invention relates to an arrangement in ring rollers for towing by a tractor, said rollers containing a middle section and at least two outboard sections on either side of the middle section, the outboard sections being hinged to the middle section so that they may be folded upwards to a mainly vertical position. The middle section is provided with at least one transport wheel, arranged for engagement with the substructure when the roller is transported, e.g. on a road. The rolls of a section are arranged on a common shaft, the two ends of which are each rotatably journalled at the outer end of a downwardly dependent arm, the inner or upper end of said arm being connected to a structure included in each section, said structure generally being made as a lattice frame. 
     The frame and arms of a section are attached to its adjacent section or sections by hinges between the frames, which thus may form an angled interrelationship. It has proved difficult to get the rolls, closest to a hinge, to follow the irregularities of uneven ground. Thus, some parts of the soil will not be rolled or they will be rolled too loosely. 
     The object of this invention is therefore to provide an arrangement in such rollers that will remove this inconvenience, whereby the shaft carrying the rolls of a section is connected to the frame thereof in such a way that the shaft has a limited movement in relation to the frame with respect to a vertical plane perpendicular to the direction of travel, for the purpose of allowing the shaft with the rolls to adapt itself to the irregularities of the ground irrespective of the angular relationship of the interconnected frames. 
     In a preferred embodiment of the invention, at least one of the two arms carrying the shaft is resiliently and pivotably connected to the frame. 
     In another embodiment of the invention, the arm is formed with a low torsional resistance or is made in the form of a leaf spring. 
     In a further embodiment of the invention the frame is made from a single tube, preferably of quadratic cross section, to the ends of which the arms are attached by means of rubber elements. 
    
    
     The invention will hereinafter be more fully described while referring to the accompanying drawings, in which 
     FIG. 1 is an end view of a roller according to the invention, showing frame, arm and shaft with rolls, 
     FIG. 2 is an end view of another embodiment of a roller according to the invention, wherein the arm is made of a leaf spring, and 
     FIG. 3 is a perspective view of a roller. 
    
    
     The roller, intended to be coupled to a prime mover, e.g. a tractor, contains a middle section 10 and outboard sections 11 on either side, that may be swung upwards for transport. For transport, the middle section 10 is provided with at least one carrying wheel 9 that may be lowered by a hydraulic cylinder controlled from the tractor, for keeping the roller raised above the substructure. 
     The middle section 10, as well as the outboard sections 11 are provided with a plurality of closely spaced metal rolls 1, preferably cast iron, arranged on and perpendicular to a common shaft 2 the ends of which are rotatably journalled in bearings 5 at the free ends of arms 3, so that the shafts are substantially horizontal when in operation. The arms 3 are attached to the frame 4 at their upper ends and are angularly dependent to the frame 4. 
     In FIG. 1, the arm 3 has the form of a rigid member. To make it possible for the shaft 2 to move in different angular directions with respect to the frame 4, the arms 3 may be rigid but mounted resiliently pivotable on the frame member 4 about the longitudinal axis of the frame member by means of rubber elements 6. Since the resilience is provided by rubber elements 6, it is also possible for the arm 3 to turn a small amount about its longitudinal axis. The arm 3 may also be pivotably mounted on the frame member 4 and be slightly rotatable about its longitudinal axis, by means of a rubber cushion 8 vulcanized to two steel plate 7. The leaf spring arm 3&#39; shown in FIG. 2, also works on the torsional principle, which is a distinguishing feature of the invention, but in this case the more &#34;linear&#34; portion of the spring arm 3&#39; twists, to absorb the torsional deflection caused by the angular deviation from horizontal of the shaft 2. 
     The invention is not limited to the embodiments described and illustrated on the drawings but other embodiments may also be conceived within the scope of the invention.