AERATING DEVICE AND METHOD FOR AERATING SOIL

AERATING DEVICE AND METHOD FOR AERATING SOIL

The invention relates to an aerating device for soil, comprising a frame, moving means arrange on the frame for moving the aerating device in a direction of movement over a surface to be worked, and aerating means for the soil connected to the frame and protruding in the direction of the surface to be worked, wherein the aerating means are directed so as to be arranged in the soil. The invention also relates to a method for aerating soil, wherein there is movement over a surface to be worked, and wherein during the movement aerating members are repeatedly inserted at an angle into the soil . Such an aerating device and method are known. In the prior art blades or discs are arranged in the soil and then retracted so that the soil is opened. The whole surface can be aerated by moving over the surface. A problem of the known methods and device is the fact that due to the repetitive performing of the aeration, for instance with a blade, the previously formed aerating openings are closed when a subsequent working takes place. An object of the invention is to provide an aerating device wherein the aeration takes place in improved manner, wherein the above stated problem, among others, can be resolved. This is achieved according to the invention in that the aerating device comprises coupling means for adjusting an angle between aerating means and the surface for working. Because coupling means are applied, the angle at which the aerating means work the surface or the soil can be changed, whereby the influence of a subsequent working on a previous aerating operation is reduced. The coupling means change the working angle of the aerating means during the movement over the surface. This can take place continuously or in stepwise manner. An improved aerating effect can also be obtained. A better aerating result is achieved because the working angles of successive aerations differ. The coupling means can preferably adjust the aerating means to an angle of 1 to 25 degrees. The successive aerating operations can hereby differ considerably from each other. The angle being referred to here is the angle between the working plane of the aerating means without coupling means and the working plane with coupling means, see in particular figures 1 and 3. According to the prior art, the working plane of the aerating means is substantially a plane which lies perpendicularly of the surface to be worked and which is oriented at least substantially in the direction of movement . According to the invention the aerating device is further provided in advantageous manner with a shaft which is mounted rotatably on the frame and which extends substantially horizontally and substantially transversely of the direction of movement, wherein aerating means are connected to the shaft and protrude therefrom, and drive means for this shaft which are arranged on the frame and engage on the shaft . An aerating device is hereby obtained which can be assembled in advantageous manner and wherein the aerating means are arranged substantially in a plane parallel to the direction of movement and at right angles to the surface for working. In other embodiments use is not made of a shaft with aerating means but of inserting devices connected to the frame for inserting a blade into the surface. In a preferred embodiment, the aerating means are arranged on a sub-frame connected to the shaft by means of adjustable coupling means. In another embodiment the sub-frame is connected to the frame. By arranging the aerating means on a sub-frame, this sub-frame can be tilted at an angle relative to the normal work surface ^• by means of the coupling means. A large number of aerating means are hereby tilted in one operation. The sub-frame preferably comprises a sleeve arranged around the shaft, wherein the aerating means protrude from the sleeve. The object of the invention is hereby achieved in structurally simple manner. The sleeve is tilted around the shaft, whereby with one operation a number of aerating means become active at different angles. In a preferred embodiment, the coupling means comprise two discs arranged on the shaft and two discs arranged close to the outer ends of the sub-frame, wherein the sub-frame is arranged between the two shaft discs such that the discs are arranged adjacently and wherein the adjacent discs can be secured by means of fixing means, for instance bolts. An angle can hereby be adjusted by means of the coupling means. The angle set between shaft and sleeve can be fixed. The aerating means will not now rotate around the shaft, but move eccentrically thereof, whereby the aerating means are not inserted at the same angle each time into the surface for working. The assembly of shaft and sleeve coupled by means of discs is an advantageous embodiment. Other embodiment options for the coupling between shaft and sleeve are also possible according to the invention. In another embodiment, or optionally as addition to the above stated embodiment, the coupling means can comprise an eccentric sleeve with which the shaft is connected to the frame in bearing mounted manner. The shaft itself can hereby be connected eccentrically to the frame, whereby the aerating means are placed in the soil at an angle which does not remain constant. The use of the eccentric sleeve can take place in addition to the use of the shaft with sleeve and coupling means therebetween. A greater angular deflection can hereby be obtained. An eccentric sleeve as such is known to the skilled person. According to a further embodiment, the aerating means are formed by blades, and the device preferably comprises a number of blades. In another embodiment the aerating means comprise discs and/or pins. According to a preferred embodiment, the aerating device has a hitching device for coupling the aerating device to a propelling vehicle. The aerating device is itself then free of drive means for the movement, but is pulled over the surface by means of the propelling vehicle. The propelling vehicle can also be coupled to the aerating device to transmit drive forces to the aerating means, for instance via a belt engaging on the shaft . The invention also comprises a method for aerating soil by moving the device over a surface for working and repeatedly inserting aerating members at an angle into the soil during the movement. The invention is characterized by repeatedly changing the angle at which the aeration is carried out in the soil. The aerating means will hereby root about more in the earth, whereby a better aeration is obtained. The effect of closing previously made aerating openings will also be reduced. One aerating member can already change angle during its movement through the soil, but the successively arranged aerating members are in particular inserted into the soil at a different angle. In a preferred embodiment the aerating members rotate about a variable axis. This can be embodied by making use of the eccentric sleeve or of the coupling as described above of a shaft to a sub- frame in the form of a sleeve . The aerating members do not rotate about a fixed axis, but move eccentrically thereof. The invention will be further described with reference to the accompanying figures, in which: Fig. 1 shows a perspective view of an aerating device according to a prior art embodiment, Fig. 2 shows a perspective view of a ground area having therein the active aerating members of the machine of fig. 1, Fig. 3 shows a perspective view of an aerating device according to a first embodiment of the invention, Fig. 4 shows a rear view in cross-section of the aerating device of fig. 3, Fig. 5 shows a rear view in cross-section of the aerating device of fig. 3 in another position, Fig. 6 is a rear view in cross-section of a second embodiment of the aerating device according to the invention. The aerating device according to the invention is for instance a self-propelled vehicle which can move over a ground with a surface which must be aerated. In another embodiment the aerating device can move over a ground surface while being coupled to a propelling vehicle via a hitching device 16, 17. In both cases the aerating device comprises a frame provided with moving means 7. In the embodiment shown in fig. 1 the moving means 7 comprise a roller 8 coupled in bearing-mounted manner to the frame. Moving means 7 are coupled to the frame via an adjusting device 5 with which the working depth of the aerating members can be changed. In the shown embodiment the working depth is a combination of the adjustment of moving means 7 via adjusting means 5 and hitching device 16, 17. Mounted on the frame via a bearing 14 is an integrally formed shaft 10 which is driven on one side 9 via a belt 4, disc 3, shaft 2 and coupling device 1. Coupling device 1 can 3oe coupled via a shaft (not shown) to a drive device. In another embodiment, coupling device 1 is itself a motor which can drive shaft 2. When coupled or driven, shaft 2 will rotate, whereby shaft 10 will eventually rotate , for instance as according to arrow 13, in clockwise direction in the shown perspective view. The aerating members will hereby cut through this ground surface. The aerating members are formed by blades 12 which protrude from shaft 10 and are fixed to a disc 11. The aerating members will come into contact with the ground surface on which the support roller 8 rests. The cutting means 12 will herein move counter to the direction of movement 7. Shaft 10 is provided with five discs I-V which are provided in each case with three aerating means protruding from the disc and formed by blades provided on the front side of the blade as according to arrow 13 with a sharp cutting edge. The blades are arranged such that the aerating members of the adjacent discs (I, II, III, IV, V) form a spiral. The invention can. be applied to the aerating device of fig. 1, which is shown in a prior art embodiment in common use. This will be elucidated with reference to figures 3 and further. Fig. 2 shows how the machine of fig. 1 operates in a soil layer. The "0" axis is the starting point. One of the blades of disc I (see fig. 1) 20 is standing at this moment almost vertically in the soil 21. Blade 20 is driven, see fig. 1. Because the blade has a determined thickness 22, a trench 23 will be formed. The soil layer is herein moved to the left 24 and the right 25. A distance 26 later will follow blade 27 mounted on disc II. Here too a trench 28 is formed. However, the soil bank 29, being the cut soil layer between blade 20 and 27, is shifted in the direction of blade 20 and trench 23 by lateral forces 30. Shortly afterward will follow blade 31 which is mounted on disc III and which creates a trench 32. During the creation of this trench 32 the soil bank 33 between trenches 32 and 28 is pressed in the direction of open trench 28 as indicated with arrows 34, whereby from distance 35, the position at which blade 31 is inserted into soil surface 21, trench 28 is closed by the rotating movement indicated with arrow 13. Trenches 28 and 23 are therefore pressed partly closed again by the subsequent aerating members. Trench 32 is still "open" but it will be apparent that a subsequent element will close it again. However, when blade 36 follows, this being the following blade on disc I, see fig. 1, after blade 20 has first formed a trench and the machine has moved a little forward as according to arrow 18, this blade will once again open trench 23 to form trench 37. Trench 37 remains open until the subsequent blade behind blade 27 passes by again. The placing of blade 36 in soil layer 21 has the consequence that lateral forces 38, 39 are generated, wherein a particular force 38 will have the effect of closing the formed trench 28. Fig. 3 shows an embodiment of an aerating device according to the invention which makes use of the structure corresponding with fig. 1. The same components are designated with the same reference numerals. In the prior art the known aerating means in the form of a blade create a lateral movement of the "soil banks" between the rotating blades which depends on the thickness 22 of the blades and the spiral mounting of all blades over the full width of main shaft 10. In addition, the ratio of the rotation speed 13 and advancing speed 18 are also important, as is the firmness of soil banks 33, 29. If it should be desired to modify the degree of aeration, it is now only possible to change the above variables to a limited extent . In the device according to fig. 3 the frame 15, driving 1, 2, 3, 4, support point 7 with roller 8 and hitch 16, 17 are the same as those of the machine of fig. 1. The great difference is to be found in this embodiment of the invention in the modification of main shaft 10. The modification of the main shaft will be described with reference to the combination of fig. 3 and 4. The invention can also be realized in other manner . Shaft 10 is connected to frame 15 by means of two bearings 14 and 41. The shaft can rotate as according to arrow 13. Shaft 10 has an axis 42. This is substantially parallel to ground surface 21, which is substantially flat at least locally at the position of the aerating device. Axis 42 is substantially at right angles to the direction of movement 18. Connected to shaft 10 are two discs 43, 44 which are arranged close to the outer ends of shaft 10. When shaft 10 rotates about its axis, driven here at one end 9 by means of belt 4, the shaft will rotate and the discs 43, 44 connected fixedly to this shaft 10 will co- rotate as according to arrow 13. Pins 45 are mounted in discs 43, 44. These pins protrude inward in a direction parallel to axis 42. Discs 46 are fixed to a tube 47. Discs 11 are now connected to this tube 47, and the aerating means, here once again in the form of cutting blades, are arranged on the respective discs. The aerating means protrude from the tube and thus also from sriaft 10/axis 42. In fig. 4 tube 9 is drawn in the "middle position" . The axis of tube 47 is the same as axis 42 of shaft 10. This situation in fact corresponds to the prior art situation. The thickness 22 of the aerating means largely determines the amount of aeration. Pin 45 is connected to tube 47 by means of a number of bolts 48-51. This pin and bolt combination forms the adjusting means for adjusting the angle of aerating means 12 relative to ground surface 21. By screwing in bolt 48, unscrewing bolt 49, screwing in bolt 50 and unscrewing bolt 51 the tube 47 is placed at an incline as shown in fig. 5. Aerating members 12 now no longer rotate in one plane , such as the vertical plane shown in fig. 4. Depending on the position of the blades on disc 11, the aerating means take up the position shown by 12A or 12B. Pins 45 protrude through a recess in disc 46. The movement which is not in one plane is translated in the soil layer 21 as an additional axial force 52, 53 respectively which wants to press the soil banks partly upward. It is no longer the thickness of the aerating member which is the main aerating factor, this has been partly superseded by the lateral movement as according to 54. The degree of lateral movement is directly defined by the degree of inclination of tube 47 relative to axis 42 of shaft 10. The angle 54 lies in the order of magnitude of 0 to 25 degrees, preferably between 0 and 10 degrees. The size of the angle depends, among other things, on the working depth of the aerating member. The longer the element, the smaller the angle to be adjusted. In another embodiment a disc is used as aerating member. The aerating action in the soil is then greater than with three individual blades, as drawn in fig. 3. The discs are in the ground continuously and as such will transmit any change in angle directly to the soil layer. In contrast to the prior art, the blades as described in fig. 1 no longer need be mounted in a spiral form. Although the described invention has an axial movement, this movement is directly linked to the revolutions of the main shaft . In order to increase aeration the axial stroke can be accelerated and/or it is possible to travel more slowly. The slower the travel, the more the lateral movement per unit of length is carried out in the direction of travel. Fig. 6 shows another embodiment. The same reference numerals are used for the same components. Mounted in bearing 14 is an eccentric sleeve 60 in which the main shaft 10 is mounted with bearing 61. Eccentric sleeve 60 is driven via 1, 2, 3, 4 and 62. Owing to this eccentric movement the aerating members 12 will tilt slightly further, as indicated with the two positions. This tilting as a consequence of the eccentric sleeve is additional to the already adjusted inclination of tube 47 relative to shaft 10 by means of bolts 48-51. Through the choice of rotation speed of eccentric sleeve 60 a vibrating movement can be added to the aerating members during a whole axial and radial stroke during one revolution. Hereby obtained, among other things, is a better crumbling of the soil, a lower friction force and thereby less drive power, wear and maintenance.