GB2046064A

GB2046064A - A Method for use of a Centrifugal Spreader and a Centrifugal Spreader for Performing the Method

Info

Publication number: GB2046064A
Application number: GB8007884A
Authority: GB
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1979-03-07
Filing date: 1980-03-07
Publication date: 1980-11-12
Also published as: FR2450551A1; DK83080A; GB2046064B; FR2450551B1; DE2908949A1; IT1140737B; DE2908949C2; IT8020269A0

Abstract

A centrifugal spreader has a storage container (14) and at least one driven spreading disc (15) situated at a height of at least 0.5 m from the ground. The spreader also has means for varying an upwardly inclined discharge angle (???) at which fertiliser particles are propelled from the spreading device (s) over the entire discharge range thereof to suit different crop conditions. The upwardly inclined discharge angle can be adjusted up to at least a value of + 15 DEG relative to the ground surface. Compensating change in the effective width of the spreader is achieved by changing the orientation of throwing elements 22 on the spreader disc. <IMAGE>

Description

SPECIFICATION A Method for Use of a Centrifugal Spreader and a Centrifugal Spreader for Performing the Method The invention relates to a method for the use in the field of a centrifugal fertiliser spreader provided with a storage container and a driven spreading device which is situated at a height of at least 0.50 m from the ground and which is provided with means for uniformly varying an upwardly inclined discharge angle at which fertiliser particles are propelled from the spreading device over the entire discharge range thereof for the purpose of adjusting the effective spreading width of the centrifugal spreaders to a specified width.

U.S. Patent Specification 3 394 892 already discloses a method of this kind. However, this known method is suitable only for use with centrifugal fertiliser spreaders in the field for fertilizing unplanted ground surfaces or those ground surfaces having only short plants, and in this method the replacement of the spreading device by another provides only a relatively slight change of the upwardly inclined discharge angle in relation to a plane which extends parallel with the surface which is to be spread.

If it is necessary to fertilise ground surfaces which contain plants of a taller growth, for example as would be necessary in late season fertilising, the fertiliser particles propelled from the spreading device will be projected against the upper parts of the plants so that it is not possible to achieve a specified effective spreading width.

This disadvantage occurs even if no plants are situated in the tracks of the tractor which draws the centrifugal spreader, when the access path method is used, and the plants between the said tracks are turned down by the chassis of the spreader so that a certain amount of space exists lateraily adjacent to the spreading device and the nearest tall plants.

The same disadvantage however also occurs when this known method is used for fertilising plants which have grown to a height of approximately 0.60 to 0.70 m, since this calls for a discharge angle, at which the fertiliser particles, propelled by the spreading device, are able to travel without obstruction within the rising part of the trajectory, over the upper ends of the nearest plants. The maximum adjustable 'effective spreading width of the centrifugal spreader is reached with this setting of the discharge angle within the facilities defined by the known method and this width is generally greater than the width specified for field cultivation in conjunction with the access path method.A reduction of the effective spreading width by reducing the discharge angle is not possible in this case because the fertiliser particles propelled by the spreading device would-then strike the upper parts of the plants thus again resulting in a lower effective spreading width.

It is an object of the invention to provide an improved method so that by its use and without the aid of a separate lifting device the centrifugal spreader can be employed for early and late season fertilising.

According to one aspect of the invention there is provided a method for use in the field of a centrifugal fertiliser spreader provided with a storage container and a driven spreading device which is situated at a height of at least 0.50 m from the ground and which is provided with means for uniformly varying an upwardly inclined discharge angle at which fertiliser particles are propelled from the spreading device over the entire discharge range thereof for the purpose of adjusting the effective spreading width of the centrifugal spreader to a specified width, wherein the upwardly inclined discharge angle can be adjusted up to at least a value of +150 relative to the ground surface and in addition at least one means for reducing the effective spreading width of the centrifugal spreader is provided.

By virtue of these steps it is possible for the discharge angle to be set to a value which is such that fertiliser particles propelled by the spreading device can travel without obstruction within the rising part of the trajectory over the nearest plant tips. A discharge angle which is as shallow as possible will be preferred to prevent wind effects inpairing the spreading accuracy of the centrifugal spreaders or to at least adequately minimize such effects. The resultant larger effective spreading width of the centrifugal spreader can be adapted to a specified width by means of the other appropriate step.Such a step can comprise, for example, a reduction of the driving speed, as disclosed in the British Specification 321 031, or a reduction of the frequency or length of stroke of the spreading device according to the German Patent Specification 2 548 1 13 in the case of reciprocating centrifugal spreaders. The effective spreading width can also be reduced by shortening the distance between the discharge edge and the drive shaft of the spreading device in a manner disclosed in the Prospectus No B-75 OBST D'70 of Messrs. Vicon. In spreading devices comprising centrifugal discs, such a step can also be obtained by moving the centre of gravity of the loading surface of the amount of fertiliser applied to the centrifugal disc in a direction towards the discharge edge, as is possible according to U.S.

Patent Specification 2 594 084. A reduction of the effective spreading width can also be obtained in a manner disclosed in the German Gebrauchsmuster 1 966 951 in which the width of the areas on the centrifuging discs, to which fertiliser is applied, is reduced as viewed in the direction of rotation while maintaining a preset flow rate defined by discharge openings in the storage container. If the spreading device is set to provide a specific effective spreading width in the spreading direction, the effective spreading width can also be reduced by reducing the setting angle in accordance with the German Patent Specification 1 86 140. A step of this kind can also be obtained by using a shieid in accordance with U.S. patent Specification 2 334 376 but such a shield must be equidistant from the spreading device and from the nearest upright plants.Steps for reducing the spreading width of a spreading device in the form of at least one centrifuging disc which is provided with throwing elements can also consist in changing the horizontal angle of the throwing elements in relation to the direction of rotation of the centrifuging disc, as disclosed in the German Gebrauchsmuster 1 966951.

Further optional features of the invention are set forth in claims 2-5.

The invention will now be more particularly described by way of example with reference to the accompanying drawings in which: Figure 1 is a rear diagrammatic view of a centrifugal fertiliser spreader in use for ground fertilising; Figure 2 is a rear diagrammatic view of the same centrifugal fertiliser spreader in use for late season fertilising; Figure 3 is a longitudinal sectional view of part of a centrifugal fertiliser spreader equipped with a centrifuging disc functioning as spreading device; Figure 4 is a plan view of the centrifuging disc of the spreader shown in Figure 3; Figure 5 iilustrates a spreading pattern obtainable with centrifuging disc shown in Figure 4; Figure 6 is a longitudinal sectional view of another centrifuging disc; Figure 7 is a plan view of the centrifuging disc shown in Figure 6;; Figure 8 is a longitudinal sectional view of yet another centrifuging disc; Figure 9 is a plan view of the centrifuging disc shown in Figure 8; Figure 10 is a longitudinal sectional view of the centrifuging disc of Figures 8 and 9 but with different throwing elements; Figure 11 is a plan view of the two centrifuging discs of the centrifugal spreader according to Figures 1 and 2; Figure 12 is a side view of part of a further centrifuging disc; and Figure 13 is a plan view of the centrifuging disc shown in Figure 12.

Referring to Figures 1 and 2, the centrifugal fertiliser spreader 1 shown therein comprises a frame 4 supporting two ground engageable wheels 2, and a storage container 5. Two spreading devices in the form of centrifuging discs 6 are located below the container 5 and are driven in opposite directions of rotation. The centrifuging discs 6 are driven via a transmission 7 in known manner, not shown, from the power take-off shaft of a tractor provided for drawing the spreader 1 along the ground.

Fertiliser particles fed from the container 5 onto the centrifuging discs 6 are propelled in the direction of arrows 8 at an upwardly inclined discharge angle y relative to the horizontal in a semicircle to the side and to the rear of the spreader. In the interest of clarity Figures 1 and 2 merely show lateral trajectories 9 and 10 in broken lines and lateral trajectories 11 in dashdot lines.

As shown in Figure 1, the fertiliser particles strike the ground surface 3 after passing through the trajectories 9 and this results in a spreading width S. The spreading density diminishes towards the edges on the two sides of the spreading width S and individual spreading paths must be overlapped in successive passes so that fertiliser is distributed with a uniform spreading density, i.e. a uniform spreading amount per unit area over the entire field area which is to be fertilised. This overlapping results in the effective spreading width E which is usually approximately 25% less than the spreading width S.

When using the spreader 1 for late season fertilising, as illustrated diagrammatically in Figure 2, the fertiliser particles must be propelled from the centrifuging discs 6 at a discharge angle a' which is sufficiently large to ensure that these particles can travel freely in the rising part of their trajectories II over the grown plants 12 nearest the centrifuging discs. This assumes that the plants disposed between the wheels 2 are resiliently depressed to below the centrifuging discs 6 by frame parts which travel over them and that access paths, kept free of seed, are situated in the track of the wheels 2 so that a substantial space Z is disposed between the centrifuging discs 6 and the nearest plants 12 and where appropriate such space can be extended by known downholding devices which are not shown.

The substantially larger discharge angle cg' results in a substantially greater spreading width S' and, therefore, also in a greater effective spreading width E' even if, after traversing over the trajectory 1 the fertiliser particles strike a surface 1 3 formed by the plant tops. At least one of the initially mentioned steps must therefore be taken to ensure that the fertiliser particles propelled by the centrifuging discs 6, traverse over trajectory 10 so that the spreading width S and the effective spreading width E shown in Figure 1 are again obtained. The dimension of the said effective spreading width E is defined by the working width of the machine drill used for cultivation.To avoid losses of yield it is, therefore, essential that this dimension is accurately maintained, so that in each subsequent operation, more particularly in the case of fertilising operations, the machines can always be driven along the same tracks for which access paths were kept free at the planting stage.

Figures 3 and 4 show a centrifugal spreader 14 having a spreading device comprising a centrifuging disc 1 5. The centrifuging disc 1 5 is rotatingly driven in a direction of rotation indicated by arrow 1 7 via a bevel transmission 1 6 in known manner from the power take-off shaft of a tractor provided for drawing the centrifugal spreader along the ground. The centrifuging disc 1 5 is located on a squared end 18 of a transmission output shaft 1 and secured against axial displacement by means of a cotter pin 20 so that the disc can be conveniently removed from the transmission output shafts 1 9 without tools and can be replaced by other centrifuging discs.

The surface 21 of the centrifuging disc 1 5 has a discharge angle c like the centrifuging disc 6 of the centrifugal spreader 1 illustrated in Figure 1.

Three blade-like throwing elements 22, which project outwardly beyond the outer edge of centrifuging disc 15, are equi-angularly spaced on the surface 21 of the disc 1 5. The spreading edges 24 of the lateral slip surfaces (23) associated with the throwing elements 22 are each provided in a manner previously disclosed in German Gebrauchsmuster 1966951 with a different horizontal setting angle ,i,,i' and p" relative to a respective tangent placed in the spreading edge in the direction of rotation 17 and the differences in size between each of the individual setting angles amounts to 80.

When the centrifuging spreader 14 is in use, the fertiliser particles 28, which trickle out of the container 26 through an adjustable discharge opening 27, drop onto the centrifuging disc 1 5 within a loading receiving area 29 (Figure 4) and are propelled outwardly over an approximately semicircular trajectory. This produces a spreading pattern 19, comprising the three individually overlapping individual spreading patterns 31 of the throwing elements, resulting in a spreading width S and in an effective spreading width E, as shown diagrammatically in Figure 5.

Figures 6 and 7 show a centrifuging disc 32, which can be substituted for the centrifuging disc 1 5 and which has a surface 33 with a larger discharge angle a' corresponding to the view in Figure 2. Three blade-like throwing elements are again equi-angularly spaced on the surface 33 of the centrifuging disc 32 but the differences between the horizontal setting angles P, P', P" formed between their lateral slip surfaces 23 and a respective tangent 25 placed upon their spreading edge 24 in the direction of rotation 1 7 is less and amounts to only 30. Despite the greater discharge angle a' the same spreading pattern is obtained as is illustrated in Figure 5.

The centrifuging discs 34 shown in Figures 8 to 10 differ from the centrifuging discs 1 5 and 32 in that they have flat surfaces 35 and blade-like throwing elements 36 and 37 are releasably fastened to each disc by means of countersunk screw fasteners 38.

In the embodiment illustrated in Figures 8 and 9 the lower slip surfaces 39 of the throwing elements 36 have a vertical discharge angle a but their lateral slip surfaces 40 form the same horizontal setting amgles /3, /3', /3" with respective tangents 25 placed upon their spreading edges 24 in the direction of rotation 17, as in the case of the slip surfaces 23 associated with the throwing elements 22 of Figures 3 and 4.

In contrast, the lower slip surfaces 41 of the throwing elements 37 shown in Figure 10 have a vertical discharge angle ' according to Figure 2.

In this case the differences between the horizontal setting angles p /3', " of lateral slip surfaces 42 are smaller in the same way as in the embodiment illustrated in Figures 6 and 7.

Another difference from the embodiment illustrated in Figures 3 to 7 is that only the throwing elements 36 or 37 need be exchanged for different throwing elements to change the discharge angle a and the horizontal setting angles /3, /3', ", so that it is not necessary for the centrifuging disc 34 to be releasably mounted on the output shaft 1 9 of the bevel transmission 1 6.

The two centrifuging discs 6 of the centrifugal spreader 1 illustrated in Figures 1 and 2 are shown in Figure 11. When the centrifugal spreader 1 is in use, the centrifuging discs 6 are driven in opposite directions of rotation in a manner disclosed by the German Auslegeschrift 11 80 562 so that they rotate respectiveiy in the direction of the arrows 43. Each of the centrifuging discs 6 is provided with two bladelike throwing elements 2 in which the spreading edges 24 of lower slip surfaces 44 form an upper inclined discharge angle a with respect to the ground surface 3 in accordance with the view shown in Figure 1.The spreading edges 24 of the lateral slip surfaces 23 associated with the throwing elements 22 form a horizontal setting angle y with the middle spreading direction indicated by the arrow 45, when the inner part of the lateral slip surface of the throwing element is at its shortest distance from the middle spreading direction 45, i.e. when the inner part of the throwing element in question lies on a line connecting the axes of rotation of the two discs.

If a larger discharge angle a' is provided in accordance with Figure 2, the horizontal setting angle y must be reduced to the value y' in order to achieve the same effective spreading width E, as illustrated by the throwing element 22' shown in broken lines on the right-hand centrifuging disc 6. The increase in the discharge angle a and the reduction of the setting angle y can be achieved by replacing the centrifuging discs 6 and 7 according to Figures 3 to 7 or by exchanging the throwing elements according to Figures 8 to 10.

The same change of the horizontal setting angle y must be performed when the discharge angle a is increased, even if the centrifuging discs 6 rotate in the opposite direction, i.e. in the direction of the arrows 46.

Figures 12 and 13 show another centrifuging disc 47 which can be used in the same manner with the centrifugal spreaders 1 and 14. In this centrifuging disc 47, each blade-like throwing element 49 comprising a radially inner part 49 and a radially outer part 51, which is pivotably connected to the inner part for movement in the direction of the double arrow 50 in a vertical plane in a manner disclosed in the British Patent Specification 321 031. A screw fastener 52 is provided as a locking element and the outer part 51 can be locked by means of the fastener 52 at different discharge angles a.

The inner part 49 is also provided with an arcuate slot 53 and is mounted on the centrifuging disc 47 by means of the vertical screw fasteners 54. Loosening of ring nuts 55 enables the inner part 49 to be pivoted to and fro in the direction of the double arrow 56. The inner part 49 can then be locked in a selected position by subsequent tightening of the ring nuts 55. A pointer 57 is provided on the outer part 51 of each throwing element 48 and a scale 58 is provided on each inner part 49 to enable a user to select a discharge angle a whilst a scale 59 is provided on the centrifuging disc 47 to enable a user to select an appropriate horizontal setting angle p in accordance with Figures 4, 7 and 9, or a setting angle y according to Figure 11.

Claims

1. A method for the use in the field of a centrifugal fertiliser spreader provided with a storage container and a driven spreading device which is situated at a height of at least 0.50 m from the ground and which is provided with means for uniformly varying an upwardly inclined discharge angle at which fertiliser particles are propelled from the spreading device over the entire discharge range thereof for the purpose of adjusting the effective spreading width of the centrifugal spreader to a specified width, wherein the upwardly inclined discharge angle can be adjusted up to at least a value of +150 relative to the ground surface and in addition at least one means for reducing the effective spreading width of the centrifugal spreader is provided.

2. A centrifugal fertiliser spreader for performing the method set forth in claim 1, having at least one spreading device comprising a centrifugal disc which is provided with a plurality of throwing elements and which is interchangeable with one or more other centrifugal discs, the surface of each of the interchangeable centrifugal discs having a different upwardly inclined discharge angle, wherein the lateral slip surfaces associated with the throwing elements of each disc each have a different horizontal setting angle at their spreading edges relative to a respective tangent placed on the centrifuging disc in the direction of rotation thereof and wherein the differences in the horizontal setting angles lessen with greater disc discharge angle.

3. A centrifugal fertiliser spreader for performing the method set forth in claim 1, having at least one spreading device comprising a centrifuging disc which is provided with a plurality of throwing elements, wherein the lateral slip surfaces associated with the throwing elements are each provided with a different horizontal setting angle at their spreading edges relative to a respective tangent placed upon the centrifuging disc in the direction of rotation thereof, wherein the lower slip surfaces of the throwing elements have an upwardly inclined discharge angle at their spreading edges, wherein the throwing elements can be interchanged with throwing elements whose lower slip surfaces have a different upwardly inclined discharge angle at their spreading edges and wherein in the throwing elements in which the lower slip surfaces have a larger upwardly inclined discharge angle, the differences between the horizontal setting angles of their lateral slip surfaces relative to respective tangents placed on their spreading edges in the direction of rotation thereof are smaller.

4. A centrifugal spreader for performing the method set forth in claim 1, comprising two centrifuging discs rotatable in opposite directions relative to each other and each provided with a plurality of throwing elements, wherein the lower slip surfaces of the throwing elements have an upwardly inclined discharge angle at their spreading edges relative to a ground surface and the lateral slip surfaces associated with throwing elements form a horizontal setting angle at their respective spreading edges relative to the middle spreading direction in the region between the centrifuging discs and a lesser horizontal setting angle is provided for a greater discharge angle.

5. A centrifugal spreader for performing the method according to claim 1, having at least one spreading device comprising a centrifuging disc which is provided with a plurality of throwing elements, wherein each throwing element comprises a radially inner part, a radially outer part which is pivotable relative to the inner part in a vertical plane and means for locking the outer part at different angular positions relative to the inner part and wherein the inner part of each throwing element is mounted on the centrifuging disc so that the angle which it makes with a radius of the disc can be adjusted in the horizontal plane and so that it can be locked in different angular positions.

6. A centrifugal fertiliser spreader, substantially as hereinbefore described with reference to and as shown in Figures 3, 4, 6 and 7, or Figures 8 10, or Figure 11, or Figures 12 and 13 of the accompanying drawings.