Mowing device

Abstract

Mowing device for plants, comprising at least one rotor with a rotor axis, in particular a vertical rotor axis or first rotation axis, and at least one blade which is driven in rotation by the rotor, in which the blade is attached to a blade holder, which is attached to the rotor so as to be rotatable about a second rotation axis which is situated at a radial distance from the rotor axis.

What is claimed is: 
     
         1 . A mowing device, comprising:
 at least one rotor for rotation about a first rotation axis;   at least one blade holder;   at least one blade driven in rotation by the rotor;   wherein the blade is attached to the blade holder, and the blade holder is attached to the rotor and is at least potentially rotatable about a second rotation axis situated at a radial distance from the first rotation axis.   
     
     
         2 . The mowing device according to  claim 1 , wherein the blade holder is rotatable between a normal operating position, in which the orbit path of the blade holder has a greatest first diameter, and a retracted impact position, in which the orbit path has a greatest second diameter, the first diameter being greater than the second diameter. 
     
     
         3 . The mowing device according to  claim 2 , provided with means for forcing the blade holder to the impact position. 
     
     
         4 . The mowing device according to  claim 1 , wherein the connection of the blade holder to the rotor comprises a shearing connection which keeps the blade holder in the normal operating position. 
     
     
         5 . The mowing device according to  claim 1 , wherein the second rotation axis, viewed in a perpendicular projection on a plane at right angles to the first rotation axis, is situated outside the blade. 
     
     
         6 . The mowing device according to  claim 5 , wherein the second rotation axis, viewed in the direction of rotation of the rotor, is situated in front of the frontmost radial plane through the first rotation axis and the blade. 
     
     
         7 . The mowing device according to  claim 1 , wherein the distance between the second rotation axis and the first rotation axis is smaller than the distance between the radial inner end of the blade and the first rotation axis. 
     
     
         8 . The mowing device according to  claim 1 , wherein the assembly of blade holder and blade, viewed in the normal operating position, consists of a first portion which is situated, viewed in the direction of rotation of the rotor, in front of the radial plane with respect to a radial plane through the first rotation axis and the second rotation axis, and a second portion, adjoining the first portion and situated behind said radial plane to which the blade is attached, and wherein the first portion has a mass which is greater than the mass of the second portion. 
     
     
         9 . The mowing device according to  claim 1 , wherein the rotor is provided with several separate blade holders which are each provided with a blade and which are arranged at regular distances from one another in the direction of rotation. 
     
     
         10 . The mowing device according to  claim 9 , wherein, viewed in a perpendicular projection on a plane at right angles to the first rotation axis, the blade holders determine an interrupted plane. 
     
     
         11 . The mowing device according to  claim 4 , wherein the shearing connection is designed to release several blade holders upon said impact so that they can rotate. 
     
     
         12 . The mowing device according to  claim 11 , wherein the shearing connection is arranged in between blade holders. 
     
     
         13 . The mowing device according to  claim 1 , wherein the rotor is provided with one or more stops for limiting the rotation of the blade holder about the second rotation axis. 
     
     
         14 . The mowing device according to  claim 1 , wherein the blade is attached to the blade holder so as to be rotatable about a third rotation axis which is substantially parallel to the first rotation axis and is situated at a distance from the second rotation axis. 
     
     
         15 . The mowing device according to  claim 14 , wherein the second rotation axis, viewed in the direction of rotation of the rotor, is situated in front of a radial plane through the first rotation axis and the third rotation axis. 
     
     
         16 . A mowing device, comprising:
 a rotor with a first rotation axis;   at least one blade holder for holding a blade; and   at least one blade rotatably driven by the rotor;   wherein the at least one blade is, during normal operation, attached to a corresponding blade holder by a blade pivot pin or shaft which is situated at a radial distance from the first rotation axis, so as to be freely rotatable at least through a predetermined angle, and wherein the blade pivot pin can be displaced radially inwards.   
     
     
         17 . The mowing device according to  claim 16 , wherein the blade pivot pin is displaceable with a tangential directional component which extends in the same direction as the direction of rotation of the rotor. 
     
     
         18 . The mowing device according to  claim 16 , wherein the blade holder is connected to the rest of the rotor about a latent dedicated second rotation axis, which is situated at a distance from both the first rotation axis and the pivot pin. 
     
     
         19 . The mowing device according to  claim 16 , wherein the first and second rotation axes and the pivot pin determine a triangle in a plane of projection at right angles to the first rotation axis. 
     
     
         20 . A mowing device, comprising at least one rotor with a first rotation axis, and at least two blades driven in rotation by the rotor, wherein each blade is attached to an associated blade holder, and wherein the blade holders are parts which are separate from one another and are attached to the rotor via a shearing connection. 
     
     
         21 . The mowing device according to  claim 20 , wherein the shearing connection is active between both blade holders. 
     
     
         22 . The mowing device according to  claim 20 , wherein the shearing connection is active between each blade holder and a central part of the rotor. 
     
     
         23 . The mowing device according to  claim 22 , wherein the central part of the rotor forms a hub for locking the bearings of the rotor. 
     
     
         24 . The mowing device according to  claim 22 , wherein the central part is attached to a hub which is intended for locking the bearings of the rotor. 
     
     
         25 . The mowing device according to  claim 22 , wherein the rotor drives the blade for rotation in a blade rotation plane, furthermore provided with means for bringing the blade outside the blade rotation plane when the blade holder is rotated with respect to the rest of the rotor. 
     
     
         26 . The mowing device according to  claim 25 , wherein said means comprise inclined surfaces for the blade holder which become active upon rotation of the blade holder about its rotation axis. 
     
     
         27 . The mowing device according to  claim 26 , wherein the inclined surfaces engage with the bottom side of the blade holder and extend upwards. 
     
     
         28 . The mowing device according to  claim 25 , wherein said means comprise an arrangement of the blade holder in which the rotation axis for the blade holder is at an angle to the blade rotation plane. 
     
     
         29 . The mowing device according to  claim 28 , wherein the rotation axis of the blade holder extends in an upward direction and, viewed in the direction of rotation of the blade holder about its rotation axis, backward direction with respect to a line which contains the rotation axis of the blade holder and a point of the blade. 
     
     
         30 . A mowing device, comprising at least one rotor with a first rotation axis, and at least one blade driven in rotation by the rotor which rotates in a blade rotation plane, in which the blade is attached to a dedicated blade holder, which co-rotates with the rotor, wherein the blade holder is connected to the rest of the rotor via a shearing connection and, when the latter breaks, is rotatable with respect to the rest of the rotor, and wherein the rotor is provided with means for bringing the blade outside the blade rotation plane when the blade holder is rotated with respect to the rest of the rotor. 
     
     
         31 . A mowing device, comprising at least one rotor with a first rotation axis, and at least one blade which is driven in rotation by the rotor, in which the blade is attached to a blade holder, which co-rotates with the rotor and is attached to the rotor so as to at least potentially be rotatable about a second rotation axis which is situated at a radial distance from the rotor axis, and wherein the centre of gravity of the blade holder with the blade, viewed with respect to a line through the first and the second rotation axes, is situated on the side of that line which is turned away from the blade. 
     
     
         32 . A blade holder for use in the mowing device according to  claim 1 . 
     
     
         33 . A cutting disc assembly comprising a beam with a plurality of mowing devices according to  claim 1  arranged thereon. 
     
     
         34 . A method for mowing plants, in which plants are mowed using a mowing device comprising at least one rotor with a rotor axis or first rotation axis, in particular a vertical rotor axis, and at least one blade which is driven in rotation by the rotor, in which a blade edge of the blade is turned opposite to the direction of rotation of the rotor in order to cut the plants while passing through a first orbit path, in which the blade, when it encounters an object which cannot be cut, rotates under the effect of a centrifugal force resulting from the rotor rotation about a second rotation axis at a radial distance from the first rotation axis to a stable, retracted position under the effect of a centrifugal force of the rotor rotation, in which it follows a second orbit path which is concentric to the first orbit path but has a smaller diameter.