Abstract:
A device for spreading granular and/or powdery material comprising a hopper for material to be supported and at least two distributing members rotated in opposite directions about vertical rotary axes, material feeding means provided between the hopper and distributing members for feeding material from the hopper to the distributing members so that each of the two distributing members receives the material eccentrically with respect to its rotary axis; the distributing members having such shape and being drivable in a manner, and the feeding means being constructed and disposed whereby in operation material is supplied to the distributing members so that each spreads material across a sector which substantially coincides with the sector across which the other distributing member spreads material. With such a device the material is advantageously spread uniformly and different materials may be spread in the same manner without the need for readjusting various members of the device.

Description:
This invention relates to devices for dispensing granular and/or powdery material. 
     According to the present invention there is provided a device for spreading granular or powdery material or both comprising a hopper for the material to be spread and at least two distributing members drivable in opposite senses about upwardly extending rotary axes, feeding means being provided between the hopper and the distributing members for feeding material from the hopper to the distributing members so that each of the two distributing members receives the material eccentrically with respect to the rotary axis; the distributing members having such a shape and being drivable in such a manner, and the feeding means being constructed and disposed such that in operation the material is supplied to the distributing members in a manner such that each of the distributing members spreads the material across a sector about its rotary axis which substantially coincides with the sector across which the other distributing member spreads the material. With such a device the material can be advantageously spread in a very regular manner and different kinds of material can invariably be spread in the same manner without the need for readjusting various members of the device. 
     The distribution of the material is enhanced when a distributing member comprises a conical portion which is located, viewed in plan, beneath outlet ports of the hopper. The material flows through the outlet ports towards the conical portion of the distributing member and via this portion in an advantageous manner towards ejection blades of the distributing member. 
     Dosing of the material to be dispersed can be advantageously adjusted by providing dosing plates between the hopper and the distributing members, these plates being coupled in common with a setting shaft of a setting mechanism, which setting shaft is rotatable from a driver&#39;s seat on the device or from a vehicle moving the device. 
     An advantageous form of device is obtained if the hopper and the distributing members are supported by a frame comprising a vertically extending framework located on one side of the device and having fastened to it supporting arms and a supporting beam for supporting the hopper and the distributing members. 
     For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example to the accompanying drawings in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a front view of the major part of a device for spreading granular and/or powdery material, 
     FIG. 2 is a side view of the device of FIG. 1, taken in the direction of arrow II in FIG. 1, 
     FIG. 3 is a plan view from above in the direction of arrow III of the major part of the device of FIGS. 1 and 2, 
     FIG. 4 is a vertical sectional view on a larger scale of part of the device of FIGS. 1 to 3, taken on the on the line IV--IV in FIG. 3, 
     FIG. 5 is a plan view from above of the part of the device shown in FIG. 4 taken on the line V--V in FIG. 4, 
     FIG. 6 is a sectional view on a larger scale of a detail of the part shown in FIGS. 4 and 5, taken on the line VI--VI in FIG. 5, 
     FIG. 7 is a vertical sectional view on a larger scale of part of drive mechanism for distributing members of the device of FIGS. 1 to 6, taken on the line VII--VII in FIG. 1, 
     FIG. 8 is a sectional view taken on the line VIII--VIII in FIG. 7, 
     FIG. 9 is a vertical sectional view on a larger scale of a further part of the drive mechanism for the distributing members, taken on the line IX--IX in FIG. 2, 
     FIG. 10 is a detail view showing an alternative form of an agitator located near an outlet of a hopper of a device such as illustrated in FIGS. 1 to 9, and 
     FIG. 11 shows an alternative form of part of a setting mechanism for dosing members of a device such as illustrated in FIGS. 1 to 9. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The device illustrated in FIGS. 1 to 9 is a dispenser for spreading granular and/or powdery material or both, particularly fertilizer or seeds, and is adapted for attachment to the lifting device of a tractor. The device has a frame 1 on which are mounted a hopper 2 and two distributing members 3 and 4 that rotate about upwardly extending rotary axes 72 and 73. The axes 72 and 73 are located in a vertical plane 220 which is at right angles to the intended direction of operative travel of the device over the ground, indicated by arrow 195. The frame includes an upwardly extending, quadrangular framework located at the front of the device and comprising two upwardly extending hollow beams 6 and 7 of rectangular cross-section interconnected at their top ends by a circular-section beam 8 and near their lower ends by a circular-section beam 9. At the level of the beam 9 located at a short distance above the lower ends of the beams 6 and 7 a V-shaped supporting beam 10 is fastened to the beams 6 and 7. The limbs 11 and 12 of the beam 10 converge away from the beams 6 and 7 and are interconnected at the rear of the device by a curved part 13. The curved part 13 is provided with upper and lower lugs 35 and 36 having registering apertures 37. The connection of the beam 10 with the beams 6 and 7 is reinforced by strip struts 14 and 15. 
     Approximately midway of their height the beams 6 and 7 have fastened to them supporting arms 16 and 17 of angular cross-section. The arms 16 and 17 and the beam 10 extend parallel to a plane normal to the framework comprising the beams 6 to 9. The connection of the beams 16 and 17 with the beams 6 and 7 is reinforced by strip struts 18 and 19. The beam 8 is provided with a supporting strip 20, the connection of the strip 20 with the beam 18 having reinforced by a plurality of strut plates 21. The strip 20 has a length equal to that of the beam 8 and therefore, like the beam 8, it is located, as shown in the front view of FIG. 1, between the beams 6 and 7. The strip-shaped beam 20 is at an angle 22 of about 35° to the plane normal to the framework of beams 6 to 9. 
     The beam 9 has fastened to it two pairs of upwardly and forwardly inclined plates 23, 24 and 25, 26, the plates 23, 24 or 25, 26 of each pair being fastened as is shown in FIG. 1, at a short distance from one another to the beam 9, and each pair being at a distance 27 or 28 from the median plane 29 of the device. Each of the plates 23 to 26 has two apertures 30 and 31, the apertures 30 and the apertures 31 respectively of the plates registering with one another. Midway of beam 8 a pair of plates 32 and 33 is provided, each of these plates having an aperture 34. The apertures 34 are in register with one another. 
     Viewed in plan, the hopper 2 has an elongated rectangular shape with its direction of length parallel to the frame-work of the beams 6 to 9. The hopper 2 has two funnel-shaped outlet parts 40 and 41, located in a front view each on one side or the other of the vertical plane 29 passing through the center of the device. The funnel-shaped outlet parts 40 and 41 have a height 42 which is substantially equal to half the height 43 of the hopper 2. At the top the hopper has rims 44 extending upwards and inwards at an angle 45 of about 15° to the vertical. The rims 44 are of a height 46 which is substantially equal to one-fifth of the height 43 of the hopper. The hopper 2 extends transversely of the vertical plane 29 over a distance 47 which is equal to substantially one and a half times the distance 48 between the beams 6 and 7. It should be noted here that in FIG. 1 one side of the hopper is not shown completely, whereas in FIG. 3 the other side is not shown completely. 
     The centers of the lower ends of the outlet parts 40 and 41 are spaced apart by a distance 49 which is smaller than the distance 48. The distance 49 is substantially equal to two-thirds of the distance 48. The outlet parts 40 and 41 are rectangular in a horizontal cross-section and the walls of these parts and of the hopper are inclined upwards up to the lower edges of the rims 44. The front and rear walls 60 are at angles 62 of about 55° to the horizontal plane, and the sidewalls 63 and the adjoining funnel walls 64 are at angles 65 of about 40° to the horizontal plane. The hopper is divided into two compartments by a partition 61 which is located above the adjoining funnel walls 64 and is in the median plane 29. The partition 61 may be removable. 
     The lower ends 50 and 51 of the outlet parts 40 and 41 are formed separately from the remainder of the hopper and they have rectangular upper ends that fit to the lower ends of the remainder of each part 40 or 41, the lower ends 50 and 51 being welded in position. The lower ends 50 and 51 are shaped so that in downward direction they merge into a circular cross-section so that they have bottoms 52 and 53 which are circular, viewed in plan. 
     The hopper 2 is provided at the front with an angular cross-section beam 54 which is welded to the front of the hopper. The hopper is fastened with the aid of the beam 54 to the supporting strip 20 of the framework by means of bolts 55. The lower ends 50 and 51 of the funnel-shaped outlet parts 40 and 41 of the hopper are provided with fastening strips 56 and 57 respectively which are fastened by means of bolts 58 and 59 respectively to the supporting arms 16 and 17 of the frame 1, as is illustrated in FIGS. 1 and 2. The strips 56 and 57 preferably have a length substantially equal to the length of the supporting arms 16 and 17 along the lower ends 50 and 51. 
     Each of the bottoms 52 and 53 has two outlet ports 66 and 67, 68 and 69 respectively (FIG. 3). The outlet ports 66 and 67 in the bottom 52 are mirror images of the apertures 68 and 69 with respect to the vertical plane 29. The apertures 68 and 69 cover an angle 82 of about 70° around the rotary axis 72. The center of the apertures 66 and 68 are located near vertical planes 70 and 71 parallel to the plane 29 and passing through the center lines of the bottoms 52 and 53. These center lines coincide with the rotary axes 72 and 73 of the distributing members 3 and 4 respectively. The center of the port 67 is displaced through an angle 74 of about 45° with respect to the plane 70. Since the ports in the bottom 52 are the mirror images of the ports in the bottom 53, the port 69 is likewise displaced through an angle 75 of about 45° with respect to the plane 71. The ports 67 and 69 are located on the distant sides of the planes 70 and 71. The ports 66 and 69 are identical and, as is shown for the port 67 in FIG. 5, they have straight sides 76 and 77 extending vertically in radial planes from the axis 72. Each port has furthermore two sides 78 and 79 curved concentrically with respect to the axis 72 with the side 78 located nearer the circumference of the bottom 52. The distance between the sides 78 and 79 is equal to about one third to one quarter of the radius 80 of the bottom 52. 
     Beneath each of the bottoms 52 and 53 there is a dosing plate 86 or 87 respectively. The plates 86 and 87 are generally flat and their top faces engage the flat lower faces of the bottoms 52 and 53. The plates 86 and 87 have flaring rims 88 and 89 respectively which are located at a slightly higher level than the remainder of the plates 86 and 87, as shown in FIGS. 1 and 4. The rims 88 and 89, as is shown for the rim 88 in FIG. 5, cover an angle 90 of about 110° around the axes 72 and 73 respectively. The rims 88 and 89 are located on the proximal sides of the funnel-shaped outlet parts 40 and 41. As is shown for the rim 88 in FIG. 5, each rim has three apertures, one aperture 91 being located centrally along the rim 88 and the apertures 92 and 93 being located near the ends of the rim. 
     The dosing plate 86 has two dosing openings 94 and 95 corresponding with the ports 66 and 67. In a similar manner the dosing plate 87 has two dosing openings 96 and 97 corresponding with the ports 68 and 69. The openings 94 to 97 are identical to each other and the openings 94 and 95 are mirror images of the openings 96 and 97 with respect to the vertical plane 29. The shape of each of the openings 94 to 97 slightly differs from that of each of the ports 66 to 69, as will be described more fully for the opening 95. 
     From FIG. 5 it will be apparent that the opening 95 has two curved sides 99 and 100 which are concentric to the axis 72 and are spaced apart from the axis 72 by the same distances as the sides 78 and 79 of the port 67. Further, the opening 95 has a side 101 which extends in a plane radial of the axis 72. This side 101 is located on that side of the opening 99 which is remote from the opening 94. The remaining side 102 of the opening 95 is at an angle 103 of about 20° to a radial plane passing through the axis 72 and the end of the side 102 remote from the axis 72. 
     As is shown in detail in FIG. 4 for the plate 86, each of the dosing plates is supported by a supporting ring 106 which is fastened to the bottom 52 by means of bolts 107. Between the bottom 52 and the supporting ring 106 there is a spacer ring 108 which is slightly thicker than the dosing plate 86. The spacer ring 108 has a diameter slightly smaller than the supporting ring 107, as will be seen from FIG. 4, so that between the bottom 52 and the supporting ring 106 a groove is formed in which the plate 86 is located so that it can turn around the spacer ring 108 while bearing on the supporting ring 106. 
     The dosing plate 86 is pivoted to a setting arm 111, one end of which is engaged in the aperture 91 of the rim 88 in the operational condition illustrated. The setting arm 111 is pivoted to an arm 112 which is rigidly coupled with a setting shaft 113. In the same manner as described for the dosing plate 86, the dosing plate 87 is coupled through a setting arm 114 with an arm 115 which is also rigidly secured to the shaft 113 so that the arms 112 and 115 occupy identical positions relative to the shaft 113. One of the setting arms 111 and 114 has an arm lengthening member 110 so that the distance between the rims of the dosing plates and the arm concerned of the setting shaft 113 can be slightly varied. As illustrated the member 110 is provided in the arm 111. The shaft 113 is rotatably journalled in a support 116, which is fastened to the lower end 50 of the outlet part 40, and in a support 117 which is fastened to the lower end 51 of the outlet part 41. Near the center of the machine the shaft 113 has a coupling arm 118 which is displaced 180° with respect to the arm 112. The coupling arm 118 is connected with an operating cable 119 which is held in a support 120 and passed, on the side of the support 120 remote from the arm 118, through an outer cable 121. The support 120 is carried by a bridge support 122 of strip form which is connected with the proximal sides of the lower parts 50 and 51 of the outlets 40 and 41 of the hopper 2. 
     Near the support 120 the bridge support 122 is provided with a lug 123 to which an arm 124 is rigidly secured. The arm 124 extends away from the bridge support 122 to beyond the setting shaft 113 and has a bore 125 through which passes the shaft 113. The arm 124 is provided by means of a bolt 128 with an indicator plate 126 having gauge markings 127. Apart from its connection with the arm 124 the indicator plate 126 is supported by the shaft 113, the plate 126 having a bore 129 receiving the shaft 113. The bores 125 and 129 are such that the shaft 113 can turn therein. The indicator plate 126 has an elongated hole 130 in which a displaceable stop 131 is slidably arranged. The setting shaft 113 is provided with a stop arm 132 which is rigidly coupled with the setting shaft. The stop arm 132 covers a distance beyond the shaft 113 which is equal to the distance covered by the indicator plate 128 beyond the shaft 113, as is shown in FIGS. 2 and 5. 
     The distributing members 3 and 4 are fastened to upright shafts 140 and 141 respectively. The shafts 140 and 141 are journalled in bearings 142 and 143 on an elongated, square-section gear box 144. The construction and the connection of the bearings 142 and 143 are identical and shown in detail for the bearing 142 in FIG. 9. The gear box 144 contains a coupling shaft 145 which covers the whole length of the box 144 and is journalled in bearings 146 and 147, as is shown for the bearing 146 in FIG. 9 in detail. Near the bearings 146 and 147 the box 144 is closed by lids 148. The box 144 is fastened by means of two brackets 149 to supports 150 which are on the limbs 11 and 12 of the supporting beam 10. Near the lower ends the shafts 140 and 141 are provided, as is shown for the shaft 140 in FIG. 9, with bevel pinions 151 which co-operate with bevel pinions 152 near the ends of the shaft 145. Near the center of the device and of the gear box 144 the shaft 145 is provided with a bevel pinion 153. In the zone of this pinion 153 the shaft 145 in the box 144 is furthermore supported by a bearing 154. To one side of the bearing 154 the gear box has a filling aperture 138 with a closing cap 139. Through this aperture oil can be introduced into the box 144 for lubricating the various transmission members and the bearings in the box 144. 
     The pinion 153 co-operates with a pinion 155 on a junction shaft 156, the center line of which is located in the vertical plane 29. The shaft 156 is journalled in a bearing housing 157 supported on the box 144. In the side of the bearing housing 157 remote from the box 144, the shaft 156 terminates in a change-speed gear box 158. The portion of the shaft 156 located in the change-speed gear box 158 is provided with a spur pinion 159 having a hub 160. The pinion 159 is in mesh with a spur pinion 161 on a driving shaft 162. The driving shaft 162 is journalled in a bearing 163 in the box 158 and a bearing 164 on a support 165, which is fastened to the box 144. The support 165 is located on the front of the box 144 opposite the change-speed gear box 158. 
     On the side remote from the gear box 144 the change-speed gear box 158 has an opening 166 which has a slightly inclined disposition, as is shown in FIG. 7, and which is closed by a removable cover 167 which is at an angle 174 of about 60° to the horizontal. The cover 167 can be readily removed from, or placed on, the box 158 by means of wing nuts 168. The lower edge of the opening 166 is located at the level of a horizontal plane 169 passing through the center line of the junction shaft 156 and the coupling shaft 145. Apart from their numbers of teeth, the pinions 159 and 161 are identical and the pinion 161 has a hub 170. The ends of the hub 160 and the hub 170 facing the cover 167 are located in a vertical plane at right angles to the plane 169. The cover 167 is provided with curved supports 171 and 172 the ends of which remote from the cover 167 extend into the proximity of the hubs 160 and 170 respectively and across the ends of the shafts 156 and 162 respectively, as will be seen from FIG. 7. 
     At the end remote from the change-speed gear box 158 the driving shaft 162 is provided with a splined portion 173 emerging out of the bearing 164. The splined portion 173 constitutes a coupling end for an auxiliary shaft. The shaft 162 is located perpendicularly above the shaft 156 so that the center line of the shaft 162 is also located in the vertical plane 29. 
     The shafts 140 and 141 of the spreading members 3 and 4 extend, as is shown in FIG. 4, through central openings in the supporting ring 106, the spacer ring 108 and the bottom 52. The bottom 52 has an upwardly extending rim 176. Agitators 177 and 178 are arranged at the top ends of the shafts 140 and 141 respectively. These agitators are made from strip material and extend parallel to the respective bottoms 52 and 53 (FIG. 4). Viewed in plan, as shown in FIGS. 3 and 5, the agitators have the shape of a parallelogram with topped ends. The agitators 177 and 178 have hubs 179 fastened to the respective shafts 140 and 141 by means of pins 180. 
     Each of the distributing members 3 and 4 is surrounded by a screen 186, 187 respectively. The screens 186 and 187 are formed symmetrically with respect to the vertical plane 29 and cover each an angle of about 150° around the respective rotary axes 72 and 73. The screens 186 and 187 are fastened at their proximal ends 190, 191 to a support 189 arranged on the change-speed gear box 158. The proximal ends 190 and 191 of the screens are substantially parallel to one another and spaced apart by a distance substantially equal to the width of the change-speed gear box 158. As is shown in FIG. 2, each of the screens 186 and 187 has a vertical portion 192 which is located at the level of the distributing members and which has a height which is at least equal to or slightly larger than the height of a distributing member. At a level below the distributing member each of the screens has an inclined rim 193 which is directed downwards towards the rotary axis of the respective distributing member. Near the top at a level above the top of the relevant distributing member each screen has a bent-over rim 194 directed towards the rotary axis of the distributing member concerned. 
     The distributing members 3 and 4 are identical and the distributing member 3 will be described more fully with reference to FIG. 5. The distributing member 3 comprises, viewed in plan, a square ejection disc plate 196. Near the center this plate has a conical part 198 having an annular shape, viewed in plan. Beyond the part 198 the plate 196 is flat and normal to the rotary axis 72 of the distributing member. This flat part is provided with four curved blades 197, the inner ends 199 of which join the outer circumference the conical part 198. Viewed on plan, this circumference is located only at a slight distance beyond an imaginary circle around the axis 72 passing through the sides 78 and 99 of the ports 66, 67 and 94, 95 respectively (FIG. 5). The ends 202 of the blades are located at the corners of the plate 196, which has a square shape viewed in plan. The blades 197 are curved so that with respect to the direction of operative rotation 201 the inner ends 199 lead with respect to the outer ends 202. Within the conical part 198 the distributing member has a flat part 203, the diameter of which is smaller than the diameter of the circle passing through the sides 79 and 100 of the ports 66, 67 and 94, 95 respectively. 
     The part 198 has a height 204 substantially equal to the mean height of the ejection blades 197. The conical part 198 is at an angle 205 of about 25° to the plate 196. The inner end of each blade has a height 206 of about forty millimeters. The height 207 of the outer end of each blade is equal to about three quarters of the height 206 and amounts to about thirty-two millimeters. The diameter 200 of the circumference of the conical part 198 is substantially equal to half the distance 208 between opposite sides of the ejection disc plate 196, this distance 208 being about forty centimeters. The diameter 209 of the circle around opposite corners of each ejection disc plate 196 amounts to about fifty-seven centimeters. The diagonals of the distributing members 3 and 4 are relatively off-set through 45° about the respective rotary axes 72 and 73, as is shown in FIG. 3. The distance 49 between axes 72 and 73 is about one and a half times the distance 209. 
     As mentioned above, the distributing member 4, which is not shown in detail, is identical to the distributing member 3, the distributing members 3 and 4 being relative mirror images of one another with respect to the vertical plane 29. 
     When the device is to be used it is hitched to the lifting device of a tractor. The lower arms of the lifting device are coupled between the plates 23 and 24, and the plates 25, 26 respectively, whereas the top arm can be coupled with the frame between the plates 32 and 33. The lifting arms can be coupled with the respective plates by passing a coupling pin through the respective holes 30 or 31 and 34. In this embodiment the side of the device coupled with the lifting device of the tractor is the front side. The device may, however, also be coupled with a vehicle provided, for example, at its front with a lifting device in which case the front side of the device becomes the rear side of the device with respect to the direction of operative travel over the ground. 
     In this embodiment the device is moved in operation in the direction of the arrow 195. When the device is attached to the tractor the end 173 of the driving shaft 162 is coupled by means of an auxiliary shaft with the power take-off shaft of the tractor. The operating cable 119 with the outer cable 121 can be coupled by means of a coupling member (not shown) having a control-arm with the tractor to give a sort of a Bowden cable arm arrangement in such a way that the cable 119 can be drawn or pushed for actuating the arm 118 as will be described more fully hereinafter. 
     The device is intended for dispensing granular or powdery material or both, which can be carried in the hopper 2. The material can be supplied from the hopper through the funnel-shaped parts 40 and 41 and the outlet ports 66, 67 and 68, 69 respectively to the distributing members 3 and 4 respectively. The amount of material to be supplied to the distributing members per unit time can be controlled by setting the dosing plates 86 and 87 with respect to the bottoms 52 and 53 so that the ports 94, 95 and 96, 97 respectively more or less overlap the ports 66, 67 and 68, 69 respectively. The material falling though the ports out of the hopper arrives at the conical portion 198 of the distributing member concerned. From this conical portion the material flows effectively towards the beginning or leading edge of each blade located nearest the rotary axis of the distributing member, by which it can be evenly spread across the desired sector. It is important in this respect that the distance 81 between the axis 72 and the side 79 of the outlet ports should be equal to about one eighth of the diameter 209 of the circle around opposite corners of each plate 196. 
     The distributing members 3 and 4 are driven from the power take-off shaft and the driving shaft 162 via the pinions 159 and 161 and the bevel pinions in the gear box 144 so that they rotate in opposite senses, the proximal edge portions of the distributing members moving in the direction of arrow 195, that is, in the direction of travel over the ground. The speed of rotation of the distributing members about their rotary axes 72 and 73 is preferably adjustable. In this embodiment the speed of rotation of the distributing members can be adjusted by exchanging the pinions 159 and 161 for other pinions. The pinions 159 and 161 are fastened by means of splines (not shown) to the shafts 156 and 162 respectively so that they are slidable along these shafts for ready replacement by other pinions. For replacing the pinions 159 and 161 by other pinions, or for interchanging them, the cover 167 can be removed from the change-speed gear box 158 by loosening the wing nuts 168. When the cover 167 is removed the supports 171 and 172 are also removed, which supports prevent movement of the interchangeable pinions 159 and 161 along the shafts 156 and 162 when the cover 167 is in place. An appropriate set of pinions consists of pinions for the shaft 156 having 14 to 21 or 23 teeth respectively and pinions for the shaft 162 having 12 or 14 to 21 teeth respectively. The potential combinations of such a set of pinions permit selecting a speed of rotation of the distributing members between about 280 and about 810 rev/min with a speed of rotation of the power take-off shaft of the tractor of 540 rev/min. The transmission ration between the bevel pinions in the gear box 144 is 1:1. 
     The location of the passage above each of the distributing members is such that each of the distributing members mainly spreads the material in a direction, opposite the direction of movement 195 across the ground, extending over substantially equal distances on either side of the vertical plane 29. Thus the material spread by the distributing member 3 is deposited on the same sector as the material spread by the distributing member 4. By causing the two distributing members to spread the material across the same sector during the operation of the device any irregularities in the distribution by one distributing member will tend to be eliminated by the other distributing member. In this way a very uniform distribution of the material is obtained throughout the width covered by the device during each run. Thus uniform distribution is further enhanced by the fact that the locations of the ejection blades of the distributing members around the rotary axes 72 and 73 respectively are relatively off-set through 45° as will be apparent from the position of the ejection disc plates 196 indicated by broken lines in FIG. 3. 
     The size of the passage through the outlet ports 67, 66 and 68, 69 respectively is determined by the extend of overlap of the openings 94, 95 and 96, 97 and the ports 66 to 69. This overlap can be varied via the operating cable 119, by which the shaft 113 can be turned. Through the setting arms 111 and 112 rotation of the shaft 113 results in rotation of the dosing plates 86 and 87 around the rotary axes 72 and 73 respectively. The stop arm 132 is fastened to the shaft 113 in a manner such that near the lower end of the slot 130 in the guide plate 126 this arm engages a fixed stop 133, at which position the outlet ports 66 to 69 are completely closed and do not at all coincide with any one of the dosing apertures 94 and 95 or 96 and 97. By turning the shaft 113 in a manner such that the arm 132 moves upwards as shown in FIG. 2, the openings 94 to 99 are brought into overlapping relationship with the ports 66 to 69. When the arm 132 is located near the top end of the slot 130 the openings 94 to 97 fully overlap the ports 66 to 69. By means of the adjustable stop 131 the upward movement of the arm 132 can be limited. Thus a position can be set that is known to result in a desirable maximum overlap of the openings 94 to 97 and the ports 66 to 69. The stop 131 may, for example, be set so that the arm 132 can be moved upwards only to an extent such that the outlet ports overlap by only half their size the dosing openings. The stop arm 132 can be moved rapidly from the fixed stop 133 towards the adjustable stop 131 for opening or closing the outlet ports to the desired extent. The sides 78 of the openings 94 to 97, which are first to get below the outlet ports or last to move away from below these ports when the ports 66 to 69 are opened or closed respectively, do not extend radially as has been explained for the side 78. It is thus ensured that when only a small portion of the outlet ports 66 to 69 is open the size of the passages will be such that the material can readily flow out of the hopper. 
     The setting arms 111 and 114 may be coupled with the respective dosing plates at least two different places. In this embodiment the setting arms may alternatively be arranged in the openings 92 or 93 of the dosing member 86 or 87 respectively. By arranging, for example, the setting arm 111 in the opening 92, the dosing plate 86 is turned so that the opening 94 can co-operate with the port 67, whereas the port 66 remains constantly closed. Thus, for example, only the ports 67 and 69 will allow material to pass to the distributing members. Thus the amount of material distributed per unit time and the width of spread can be reduced. The arms 111 and 114 may also be arranged in the openings 93 of the dosing plates 86 and 87. Then the openings 95 and 97 will co-operate with the ports 66 and 68. Thus the width of spread remains larger than in the case in which material is only supplied through the ports 67 and 69 to the distributing members. For the mentioned co-operation between the openings in the dosing plate and the outlet ports it is essentional that the angle between the openings 91 and 93 and the openings 91 and 92 is equal to the angle through which the centers of the outlet ports 66 and 67 are off-set around the rotary axis 72. As a further alternative one of the setting arms may be uncoupled from the dosing plate concerned, the dosing plate being retained in the position in which the outlet ports concerned remain closed, in which case the material can be fed only from one outlet port 40 or 41 to the distributing member 3 or 4. Thus the quantity of material spread over a strip of land can be appreciably reduced. When the outlet port most remote from the plane 70 or 71 is held in the closed state, the material can be spread more to one side of the device. The relative positions of the dosing plates 86 and 87 can be slightly post-adjusted by means of the lengthening member 110 in the setting arm 112, the length of which arm can thus be slightly varied. 
     The agitatiors 177 and 178 serve to assist the flow of material through the outlet ports. These agitators rotate with the same speed around the rotary axes 72 and 73 as the distributing members. The agitators 177 and 178, which are fastened to the shafts of the distributing members by means of pins, may have a shape different from that illustrated from the device of FIGS. 1 to 9. For example, FIG. 10 shows an agitator comprising a ring 216 fastened by means of two spokes 217 to a hub 218. The hub 217 corresponds with the hub 179 shown in FIG. 4. With certain kinds of material the agitator shown in FIG. 10 may be more successful for passing the material to be spread through the outlet ports without the material being pulverized to a greater or lesser extent. 
     FIG. 11 shows schematically an alternative manner of operating the coupling arm 118, which together with the shaft 113 and accessories constitutes a setting mechanism for regulating the dosing plates 86 and 87. As is shown in FIG. 11 a double-acting hydraulic ram 211 is arranged between the coupling arm 118 and the support 120, pivotally supported by the support 120. The piston rod 212 of this ram is pivoted to the arm 118. The ram 211 is coupled by means of hydraulic lines 213 with a hydraulic control-mechanism on the tractor so that at will, by means of the ram 211 and the rod 212, the distance between the supports 120 and the arm 118 can be enlarged or reduced for turning the setting shaft 113 and hence the dosing plates 86 and 87 together or separately. 
     Although in the embodiment shown a single, long gear box 144 is used, this long box may be replaced by two small boxes for the pinions 151 and 152 for each distributing member and a further box holding the bevel pinions 153 and 155 and the interchangeable pinions 159 and 161. 
     The lugs 35 and 36 constitute a drawhook for attaching a further implement to be moved together with the device shown. The partition 61 divides the hopper 2 into two compartments. If desired different kinds of material can be carried in the separated hopper compartments, in which case each distributing member spreads a different kind of material. However, usually the hopper compartments will contain the same kind of material. The two distributing members spread the material across the same sector about their rotary axes, so that the uniformity of the distribution pattern across the area is enhanced. 
     Although various features of the devices that have been described, and are illustrated in the drawings, will be set forth in the following claims as inventive features, it is to be noted that the invention is not necessarily limited to these features but is intended to encompass all novel and inventive features that have been described both individually and in various combinations.