Abstract:
The invention concerns a device for pruning and shredding plants. It comprises a shredding head ( 1 ) arranged at the end of a steerable arm itself borne by a tractor machine adapted to move along the plants to be treated, the head comprising a housing ( 10 ) including two parallel end plates ( 11, 12 ) between which are mounted two juxtaposed rotors ( 13, 14 ) with parallel axes, equipped with radial blades ( 15 ) and adapted to be driven in rotation in opposite directions (F, R), such that the blades ( 15 ) of said rotors ( 13, 14 ) move in the space ( 16 ) which separates said rotors ( 13, 14 ) and drive therein the plants to be cut and shredded.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    (1) Field of the Invention 
         [0002]    The present invention relates to a device for pruning and shredding plants. 
         [0003]    The maintenance of the surrounding areas of roads and forest tracks or the like requires periodic pruning operations, which, in turn, give rise to plant-shredding operations in order to allow the removal and the transport of waste obtained. 
         [0004]    (2) Description of the Prior Art 
         [0005]    The pruning operations are generally carried out by means of bucking saws or the like, which are carried by hand or mounted on tractor machines, while the shredding occurs afterwards by means of plant shredders. 
         [0006]    Traditional manual cutting tools, or brush shredders, which are however ineffective when the branches exceed a certain cross-section, are also used. 
         [0007]    Pruning is a slow operation, and when high hedges or trees along traffic roads are to be treated, this can result into a slowing-down of the traffic. 
         [0008]    In addition, since shredding is an operation separated from the pruning operation, this increases the above-mentioned drawbacks. 
         [0009]    The aim of the present invention is to cope with these various drawbacks by providing a device for pruning and shredding plants, permitting not only to carry out these two operations simultaneously, but also to carry them out at a rate never reached before. 
       SUMMARY OF THE INVENTION 
       [0010]    The device for pruning and shredding plants according to the invention includes a shredding head arranged at the end of a steerable arm itself borne by a tractor machine capable of moving along the plants to be treated, said head including a housing comprising two parallel end plates between which are mounted two juxtaposed rotors with parallel axes, equipped with radial blades and capable of being driven in rotation in opposite directions, so that the blades of said rotors move in the space which separates said rotors and drive therein the plants with a view to their cutting and shredding. 
         [0011]    According to an additional feature of the pruning and shredding device according to the invention, one of the two end plates, the one aimed at being placed closest to the plants, is largely indented. 
         [0012]    According to another additional feature of the pruning and shredding device according to the invention, one of the end plates, the one aimed at being placed farthest away from the plants, is extended with a deflector capable of containing and guiding said plants towards the rotors. 
         [0013]    According to another additional feature of the pruning and shredding device according to the invention, the rotors each comprise a body in the form of a relatively large-diameter cylinder from which the blades protrude. 
         [0014]    According to another additional feature of the pruning and shredding device according to the invention, at least one of the rotors is associated with counter-blades arranged at the level of an end plate at the inlet of the space separating said rotors. 
         [0015]    According to another additional feature of the pruning and shredding device according to invention, it comprises counter-blades arranged in front of the space separating the rotors, and which each present an active edge that preferably coincides with the axis passing through the two axes of the rotors, so as to be parallel to the blades  15  when the latter intersect said counter-blades. 
         [0016]    According to another additional feature of the pruning and shredding device according to the invention, it comprises a scraper arranged in front of the space separating the rotors, designed capable of pivoting according to an axis parallel to those of the rotors, so as to be capable of adopting several positions between two end positions, one corresponding to the scraping of a rotor and the other to the scraping of the other rotor. 
         [0017]    According to another additional feature of the pruning and shredding device according to the invention, it is provided with scraping means integral with the housing, in the form of combs between the teeth of which the blades pass. 
         [0018]    According to another additional feature of the device of pruning and shredding according to the invention, the housing internally comprises means capable of slowing down the progression of the plant material after its passing through the space separating the rotors. 
         [0019]    According to another additional feature of the pruning and shredding device according to the invention, the housing comprises openings positioned in front of each rotor and aimed at evacuating the shred, said openings being provided with deflector means capable of directing the flow of shred. 
         [0020]    According to another additional feature of the pruning and shredding device according to the invention, the steerable arm is designed capable of being made integral with a tractor machine, and it has at least two, preferably at least three, degrees of freedom, so as to permit placing the shredding head according to different orientations and at different heights. 
         [0021]    The advantages and characteristics of the pruning and shredding to device according to the invention will clearly appear from the following description, which refers to the attached drawing, which represents a non-restrictive embodiment of same. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0022]    In the attached drawing: 
           [0023]      FIG. 1  shows a schematic side view of part of the device for pruning and shredding plants according to 1′ invention. 
           [0024]      FIG. 2  shows a schematic view according to another angle of the same device. 
           [0025]      FIG. 3  shows a schematic perspective view of the same device. 
           [0026]      FIG. 4  shows a schematic side view of a variant of part of the same device. 
           [0027]      FIG. 5  shows a schematic partial perspective view of an element of the same device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    When referring to these figures, one can see that a device for pruning and shredding plants according to the invention comprises a head  1  mounted at the end of a hinged arm  2 , which can be seen in  FIG. 2 . 
         [0029]    The head  1  comprises a housing  10  including two end plates  11  and  12 , which enclose and maintain two rotors  13  and  14  with parallel axes each comprising a cylindrical body provided with radial blades  15 , schematically shown and separated by a space  16  in which the blades  15  move. 
         [0030]    The two rotors  13  and  14  are driven in opposite rotation, in the direction of the arrows F and R, respectively, so as to drive the plants into the space  16 , and to propel them into the housing  10  with a view to performing its shredding. 
         [0031]    The blades  15  are preferably regularly distributed over the full surface of the bodies of the rotors  13  and  14 , so as not to favour the jamming phenomena. 
         [0032]    In order to increase the quality of shredding, the housing  10  is internally provided with means  10 ′ capable of slowing down the progression of the plant material, so as to increase the duration of presence of the latter in the area of action of the blades  15 . 
         [0033]    These means can for example consist of bars protruding out of the internal face of the housing  10  parallel to the axes of the rotors  13  and  14 , and extending between the two end plates  11  and  12 . 
         [0034]    The head  1  also includes scraping elements  17  integral with the housing  1 , and which extend between the blades  15 , in order to enter almost into contact with the bodies of the rotors  13  and  14 . 
         [0035]    The head  1  has at each of its ends, i.e. on both sides of the rotors  13  and  14 , an opening  18  allowing evacuating the shred. 
         [0036]    It should be noted that it is perfectly possible to associate to the head  1  means for collecting and evacuating the shred. 
         [0037]    The hinged arm  2 , which is in this case made integral with the end plate  12 , permits moving the head  1  with respect to the plants, and namely so that the end plate  11  remains substantially parallel to the direction of displacement and to the plants. The hinged arm  2  has several degrees of freedom, at least two, preferably three. 
         [0038]    It is thus possible to treat vertical plant walls such as hedges or the like, but also horizontal surfaces, by moving the head  1  of the end plate  11  parallel to the ground. 
         [0039]    It should be noted, as can be seen in particular in  FIG. 3 , that the end plate  11  is largely indented in order to allow an increased penetration into the plants, unlike the end plate  12 , which thus permits to contain the protrusions. 
         [0040]    It is furthermore possible to provide the head  1  with counter-blades  3 , schematically shown in  FIG. 1 , aimed at facilitating the cutting of the plants. These counter-blades  3  can consist of an extension of the end plate  11  in the area of the space  16 , and having, for each rotor  13  and  14 , a toothed edge concentric to the rotor involved, and with a radius ranging between that of the body of the rotor and that of the blades  15 . 
         [0041]    It should be noted that the head  1  is, optionally, also provided with counter-blades  30 , visible in  FIG. 1 , arranged in front of the space  16 , and which each have an active edge  31 , which preferably coincides with the axis passing through the two axes of the rotors  13  and  14 , so as to be parallel to the blades  15  when the latter intersect with the counter-blades  30 . 
         [0042]    In  FIG. 3 , one can also see that the end plate  12  is extended, at the front, i.e. at the side from which the blades  15  emerge, with a deflector  19  capable of containing and guiding the plants. 
         [0043]    The hinged arm  2  mainly comprises an arm  20  movable according to a to-and-fro motion and made integral with the head  1  in front of the rotor  14 , and a jack  21  the end of which is made integral with the head  1  in front of the rotor  13 , and which is aimed, according to its lengthening or its shortening, at changing the inclination of the head  1 . 
         [0044]    The arm  20  is backed up with a driving shaft  22 , which transmits the motion to the rotor  14 , while a transmission shaft  23  allows driving the rotor  13 . 
         [0045]    When referring to  FIG. 4 , one can see a different embodiment of the head  1 . 
         [0046]    Thus, the openings  18 , not visible, aimed at evacuating the shred, are brought closer to the median area of the housing, and each end in front of a flap  18 ′, which is steerable according to an axis perpendicular to those of the rotors  13  and  14 . It is therefore possible, by causing the flaps  18 ′ to pivot, to steer the flow of shred. 
         [0047]    It should be noted that the flaps can be replaced by chutes, also steerable, which each cover an opening  18 , thus allowing conveying the flow of shred. 
         [0048]    Furthermore, the head  1  includes in addition a scraper  4 , arranged in front of the space  16 , and which acts between the counter-blades  18 ′, this scraper  4  being designed so as to pivot according to an axis parallel to those of the rotors  13  and  14 , so as to be capable to adopting two end positions, one corresponding to the scraping of the rotor  13  and the other to the scraping of the rotor  14 . 
         [0049]    It should be understood that this scraper  4  also acts as a deflector, since, according to the end position chosen, the plants are directed towards either one of the rotors  13  and  14 . On the other hand, by positioning the scraper  4  between both end positions, the plants are directed simultaneously towards both rotors  13  and  14 . 
         [0050]    When referring now to  FIG. 5 , one can see a rotor  13  or  14 , which consists of a barrel  5  externally provided with pairs  50  of crowns  51 , aimed at making integral the blade-holders  52 . The crowns  51  are drilled with holes  53  and includes notches  54 , while the blade-holders  52  each include, on the one hand, two pins  55 , one at each end, and, on the other hand, holes, not visible. 
         [0051]    Each blade-holder  52  is inserted between two crowns  51  of a pair  50 , the pins  55  are inserted into the notches  54  and are aimed at bearing the shearing forces, the making integral being performed by means of bolts  56 . 
         [0052]    It should be noted that the notches  54  have a symmetrical shape, so as to allow fixing the blade-holders  52  in one direction or in the other. 
         [0053]    The blade-holders  52  are each provided with a blade  57 , which has a bevel  58 . As can also be seen in  FIG. 5 , the bevels  58  are oriented towards the inside of the rotor, so as to maintain the plants and thus guarantee an optimal shredding. 
         [0054]    Thus, the embodiment which has been described above comprises a pair of rotors, whereas it is perfectly possible that it comprises several pairs of them. 
         [0055]    On the other hand, the two rotors shown are of an identical size, whereas depending on the use for which the device is intended, the two rotors can be of different diameters, in order to favour, on the side of the largest rotor, a direction of propelling of the plants.