Method of spreading flowable material, apparatus for use in carrying out the method, and spreader vane for use in the apparatus

Abstract: When spreading e.g. manure by means of a rotating spreader disk (1) with spreader vanes (5), the main novel feature is that the active part (8,9) of the spreader vanes (5) is divided into an inner (8) and an outer (9) part, mutually offset radially and tangentially so as to form an opening (15). With a first sense or direction of rotation (3), the material (not shown) will slip past the openings (15) and leave the outermost end of the outer part (9) with a relatively high velocity, whilst with the opposite sense or direction of rotation (4), the material will "fall" through the openings (15) with a relatively low velocity. This makes it possible to change the throwing distance merely by changing the sense of rotation of the spreader disk (1), and by means of fixed screens or guards (not shown), this change of direction can be used at the same time to change the spreading pattern. This can especially be useful when the apparatus, e.g. fitted to a tractor, is run along a field boundary or a watercourse where the spreading of manure is not permitted.

Description: FIELD OF THE INVENTION The present invention relates to a method of spreading flowable material, such as set forth in more detail in the preamble of claim 1. BACKGROUND ART A method of this kind is disclosed in the French patent application FR 2496390A. The Danish patent application No. 1122/96 (B, S & Co. ref. 56339) describes how the spreading pattern can be changed, e.g. with a view to be able to pass along a field boundary or a watercourse without spreading e.g. manure beyond certain limits, by using a spreading apparatus with two disks and making these disks rotate in the same or opposite sense in different directions, and possibly blocking the supply of spreadable material to one of the disks. DISCLOSURE OF THE INVENTION On this background, it is the object of the present invention to provide a method of the kind referred to initially, with which it is possible to influence the spreading pattern to a greater degree, and this object is achieved by proceeding in the manner set forth in the characterizing clause of claim 1. By so doing, it is possible to change the velocity and hence the kinetic energy, with which the material is spread out, by merely changing the sense of rotation of the spreader disk or disks concerned. The present invention also relates to an apparatus for carrying out the method of the invention. This apparatus is of the kind set forth in the preamble of claim 3, and according to the invention, this apparatus is characterized by the construction and arrangement set forth in the characterizing clause of this claim 3. Finally, the present invention relates to a spreader vane for use in the apparatus mentioned above. This spreader vane is of the kind set forth in the preamble of claim 8, and according to the invention, this spreader vane is characterized by a construction as set forth in the characterizing clause of this claim 8. Advantageous embodiments of the method and the apparatus, the effects of which will be evident from the following detailed part of the present description, are set forth in claim 2 and claims 4-7, respectively. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be explained below with reference to the drawings, showing an exemplary embodiment of a spreading apparatus according to the invention, of which solely the parts necessary for the understanding of the invention are shown, whereas Figure 1 shows in perspective as viewed at a skew angle from above a spreader disk, to which two spreader vanes according to the invention are secured, Figure 2 is a top view of one of the spreader vanes shown in Figure 1, Figure 3 shows the spreader vane shown in Figure 2 with two possible flow paths for the flowable material drawn in, Figure 4 is a top view of parts of an apparatus according to the invention, and Figures 5 and 6 show the apparatus shown in Figure 4 in two different operating states. DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 shows a dish-shaped spreader disk 1 adapted to rotate about an axis 2, being generally vertical during operation, in a first sense 3 or in a second and oppposite sense 4, such as will be explained in more detail below. The spreader disk 1 carries two spreader vanes 5, each consisting of a footpiece 6, in a known manner adjustably secured to and co-planar with the disk 1 by means of bolts or studs 7, an active spreader part 8, 9 lying in or forming a small angle with a meridian plane through the axis 2 and hence forming a right angle with the disk 1, as well as guiding and stiffening plates 10, 11 and 12, extending parallel to and in different distances from the disk 1. The special feature of the spreader vanes 5 according to the present invention consists in that the active spreader part 8, 9 is divided into two parts, viz. a radially inner part 8 and a radially outer part 9, and in that the radially outer end 13 of the radially inner part 8 is offset in the radial and tangential directions relative to the radially inner end 14 of the radially outer part 9, so that, cf. also Figures 2 and 3, a gap 15, extending parallel to the axis 2 of rotation, is formed between said ends 13 and 14. As mentioned, Figure 4 shows a part of a spreading apparatus according to the present invention, in which at least the spreader disk 1 situated to the left carries spreader vanes 5 of the construction described above, whereas the spreader disk 21 situated to the right in the example shown carries spreader vanes 25 of a previously known type. Above the two spreader disks 1 and 21 there is placed in a known manner a container (not shown) for flowable material, e.g. manure in the form of granules, likewise in a known manner falling down through suitable openings 16 in the bottom of said container, as mentioned otherwise not shown. Likewise in a known manner, the material is thrown outwards by the centrifugal force, presumably assisted by the air current created by the spreader vanes 5 and 25, until it is intercepted by the vanes and thrown further outwardly from the disks 1 and 21 in spreading patterns as indicated in Figure 5, the forwardmost limit of which is determined by fixed guards 17, while the limits to the sides and the rear are determined by the throwing distance, the latter again depending on inter alia at which velocity the material leaves the spreader vanes 5 and 25. In the normal operating state shown in Figure 5, the disk 1 rotates in the sense 3, while the disk 21 rotates in the opposite sense 33. The path of movement, through which the material is assumed to travel when passing the spreader vanes 5, is in Figure 3 indicated by empty circles O - at this point it should be emphasized that during this process, both the vanes 5 and the material also moves tangentially corresponding to the normal rotational sense 3 for the disk 1. As it will be appreciated, the material "jumps" across the gap 15 and continues along the radially outer part 9, at which additional kinetic energy is imparted to it - i.e. its velocity is increased - all the way out to the extreme end of this part. In certain situations it may be necessary to limit the spreading pattern to one or the other side of the apparatus while it is being moved forward in the direction 18, e.g. carried by a tractor. Figure 6 shows such a situation, in which the material must not be spread beyond a symbolically indicated field boundary 19. To this end, the supply to the spreader disk 21 is blocked, and the spreader disks are made to rotate in the opposite senses 4 and 34, respectively, i.e. oppositely to the normal rotational senses 3 and 33. In this operational state, the material, this time symbolized by "filled" circles ⊕, will "fall down" from the radially inner part 8 through the gap 15, and thus receive considerably less kinetic energy - i.e. be given a considerably lower velocity - than in the operational state shown in Figure 5. This results in part in a decrease in the throwing distance, in part in that the fixed guide 17 associated with the disk 1 causes a cutting-off of the spreading pattern at its rear end, so that this pattern is kept clear of the field boundary 19. In the example described, the spreader disk 21 situated to the right is equipped with spreader vanes 25 of a previously known type, i.e. without the gap 15, but it lies within the scope of the present invention to provide even this disk 21 with spreader vanes 5 according to the invention. In that case it is possible to "mirror" the situation shown in Figure 6 by blocking the supply to the left-hand disk 1 and let the right-hand disk 21 spread the material in the same manner, but in a mirror image of the pattern for the disk 1 shown in Figure 6. In order to facilitate control, the manually operated cable or rod connections, possibly also hydraulically assisted remote-control means (not shown), may be common to the means determining the rotational sense of the spreader disks and the means blocking one or the other of the outlet openings 16, all in such a manner, that when a spreader disk rotates "backwards", i.e. in the sense 4 or 34, the outlet opening 16 associated with the control means will be blocked. In this case it is possible to utilize adjustable screens or guides (not shown), e.g. of the type known from EP-A2-0.699.377, and let the common remote-control means act upon these screens or guides as well, all in such a manner that a limiting screen or guide will stop material not having been caught by the fixed guides 17. The effect of this is that "stray" material will not be thrown out across the field boundary 19, but will instead hit the screen or guide and fall vertically downwards. LIST OF PARTS 1 spreader disk 2 axis 3 first sense (direction) 4 second sense (direction) 5 spreader vane 6 footpiece 7 bolts/studs 10 guiding and stiffening plate 11 guiding and stiffening plate 12 guiding and stiffening plate 13 radially outer end (of 8) 14 radially inner end (of 9) 15 gap 16 opening 17 fixed guard 18 direction 19 field boundary 21 spreader disk 25 spreader vane 33 sense (direction) 34 sense (direction)

Claims: Method of spreading flowable material using at least one spreader disk on its upper side provided with at least one generally radially extending spreader vane, said spreader disk rotating in either a first or a second, opposite sense or direction about a generally vertical axis and receiving the flowable material from above, throwing said material out beyond its peripheral edge by means of said spreader vane or vanes, characterized by the use of at least one spreader vane so adapted that when the spreader disk rotates in said first sense or direction, its engagement with the flowable material ceases at a first radial distance from the rotational axis of the spreader disk, while when the spreader disk rotates in said second, opposite sense or direction, its engagement with the flowable material ceases at a second radial distance from the rotational axis of the spreader disk, said second distance being different from said first distance. Method according to claim 1 and with the use of one or a number of spreader vanes, each comprising a base part, with which it is secured, possibly adjustably, to a spreader disk, and a spreader part protruding upwardly from the base part and having a not inconsiderable extent in the axial and radial directions, characterized by the use of at least one spreader vane, in which the spreader part comprises a radially inner part and a radially outer part, the radially outer end of the radially inner part being offset in such a manner in the radial and tangential direction relative to the radially inner end of the radially outer part, that between them there is formed an opening, through which the flowable material can pass. Apparatus for carrying out the method according to claim 1 or 2 by spreading flowable material and comprising a) at least one container for flowable material and comprising at least one outlet opening (16) for the material, b) situated below at least one of said outlet openings (16) a spreader disk (1) adapted to rotate about a generally vertical axis (2) in either a first sense or direction or in a second, opposite sense or direction, and c) at least one spreader vane (5) secured to the upper side of each spreader disk and comprising c1) a base part (6), by which it is secured, possibly adjustably, to the spreader disk, and c2) a spreader part (8,9) protruding upwardly from the base part (6) and having a not inconsiderable extent in the axial and radial directions, characterized in d) that at least one spreader vane (5) comprises a spreader part (8,9) having a radially inner part (8) and a radially outer part (9), the radially outer end (13) of the radially inner part (8) being offset in such a manner in the radial and tangential direction relative to the radially inner end (14) of the radially outer part (9), that between them there is formed an opening (15), through which the flowable material can pass. Apparatus according to claim 3, characterized in that said radially inner (8) and outer (9) parts are mutually offset in the tangential direction to such a degree that when the spreader disk rotates in a sense or direction, in which the radially inner part (8) is forwardmost, no more than an insignificant proportion of the flowable material will come into contact with the radially outer part (9). Apparatus according to claim 3 or 4, characterized by means for selectively blocking at least one outlet opening (16). Apparatus according to claim 5, characterized by common remote-control means to act upon the rotational sense or direction of the spreader disk or disks (1,21) and the means for blocking the outlet opening or openings (16) in such a manner, that when the rotational sense of a spreader disk is such that the radially inner spreader part (8) is rearwardmost, then the associated outlet opening (16) will be blocked. Apparatus according to claim 6 and of the kind comprising at least one limiting screen or guard movable between an active position, in which it constitutes an obstruction for at least a part of the material being thrown out from a spreader disk, and a passive position, in which it does not constitute such an obstruction, characterized in that the common remote-control means are also adapted to move the limiting screen or screens or guard or guards between said two positions in such a manner, that when the rotational sense or direction of the associated spreader disk is that mentioned in claim 6, then the associated limting screen or guard will be in said active position. Spreader vane (5) for use in an apparatus according to any one or any of the claims 3-7 and of the kind comprising a) a base part (6), by which it can be secured to a spreader disk (1,21) in the apparatus, and b) a spreader part (8,9) protruding upward from the base part (6) during operation and having a not inconsiderable extent in the axial and tangential directions, characterized in c) that the spreader part (8,9) comprises a radially inner part (8) and a radially outer part (9), the radially outer end (13) of the radially inner part (8) being offset in such a manner in the radial and tangential direction relative to the radially inner end (14) of the radially outer part (9), that between them there is formed an opening (15), through which the flowable material can pass.

Inventors: IVERSEN MORTEN DALL, LAURSEN NILS JORN, IVERSEN, MORTEN DALL, LAURSEN, NILS JORN
Applicants: LAURSEN AS A P, A.P. LAURSEN A/S
Application year: 1998
Main classification: A01C17
IPC codes: A01C17