US 3616973 A
Description (OCR text may contain errors)
United States Patent Gilbert Spencer Hartley Saffron Walden, England 857,490
Sept. 12, 1969 Nov. 2, 1971 Fisons Limited Felixstowe, Suffolk, England Sept. 17, 1968 Great Britain Inventor Appl. No. Filed Patented Assignee Priority GRANULE DISTRIBUTOR 20 Claims, 1 1 Drawing Figs.
Int. Cl Field of Search Primary Examiner-Robert B. Reeves Assistant Examiner-Francis .l. Bartuska Attorneywenderoth, Lind and Ponack ABSTRACT: As apparatus for the distribution of granules or particles. The apparatus has a cascade of riffles with means for supplying granules to the first riffle. The first riffle divides the supply of granules into at least two streams, and means are connected between the first riffle and at least two subsidiary riffles of the cascade to pass the streams to the subsidiary riffles. Means can also be provided to pass streams from the subsidiary riffles to at least one further subsidiary of riffles. Means is also provided for passing the streams of granules or particles from the terminal riffles of the cascade to a distribution means.
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ATTORNIL'YS PATENTEBNUVZ ml 3.616.973
SHEET 30F 5 INVENTOR G l LB ERT SPE NCER HARTLEY BY Mam, $1M
ATTOR NEYS PATENTEUHBVZ I971 3,616,973
sum w 5 INVENTOR GILBERT SPENCER HARTLEY ATTORNEYS PATENTEUuuv 2 I971 SHEET 5 OF 5 INVENTOR (3 l LB E RT SPENCER HARTLE Y ATTORNEYS GRANULE DISTRIBUTOR In agricultural practice many materials are distributed on the land in the form of particulate solids. Seeds occur in this form naturally. Chemical fertilizers are mostly used in this form. Insecticides, fungicides and other pesticides and also herbicides are sometimes fabricated in granular form because in some situations, there may be technical, convenience or safety reasons for so using them.
All these particulate solids, hereinafter called granules, may be required to be distributed for some purposes broadcast and for other purposes in lines. When distributed in lines they are often required to be buried below the soil surface. It may be necessary to distribute two kinds of granule in the same or in closely adjacent lines, as inseed sowing with fertilizer placement.
Devices for the application of granular materials to the land must in general carry out some or all of three more or less separate functions which may be called the metering, dividing and distributing functions. By metering is here meant the process of causing the mass of granules to flow out at a rate controlled to give the required amount per yard run of the carrier machine. Metering devices at present use vary from those, usually of the rotating-spoon type, in which the flow is positively controlled by the land speed of the machine, to the provision of adjustable or interchangeable orifices through which the granules flow under gravity at a constant volume speed while the machine is moved forward at 'a constant linear speed. By dividing is here meant the separation of the primary stream of granules into two or more equal streams. By distribution is here meant the conveyance of the metered stream or each portion thereof to the appropriately situated outlet.
In machines adapted to line distribution the distributor consists of a series of tubes terminating in or behind a series of soil-scraping tools or coulters. In the commonest forms of such machines, each distributing or conducting tube is fed by a single positive metering device, the function of stream-division being omitted. In the common plate-and-flicker type of distributor for granular fertilizers, the metering device is of a cruder form but each one serves a rotating flicker device and there is no conducting tube, the objective being to obtain a randomized scatter across the whole width of the machine. In the common spinner type of distributor for granular fertilizers, a plate rotating in a horizontal plane is fed nearly centrally and usually by gravity through an orifice. The falling granules are thrown off in a wide band. There are no conducting tubes and the plate may be considered to combine the functions of divider and distributor.
Machines in which a plurality of metering devices supply a plurality of streams spaced out along the width of land (swathe) it is desired to treat usually take the form of a wide rigid supply hopper which must be coextensive with the swathe width. This construction incurs two disadvantages. Firstly, the machine, if economic in use, is too wide to go through gateways or along public roads unless so made that its shape or posture can be altered for transport. Secondly, each metering device must supply only enough granules for each outlet. Unless the granules are exceptionally free-flowing it is difficult to arrange that the feed rate is at once sufficiently slow and sufficiently continuous and reliable.
In the spinner-type fertilizer broadcaster, these disadvantages are avoided because a single feed, at correspondingly higher-flow rate, is used and the granules are thrown out beyond the width of the machine. The device is however only suitable for broadcasting and it cannot achieve a reliable uniform application rate across the swathe because the distance of throw is dependent on granule size and wind as well as on speed of rotation of the plate.
It has now been found that efficient division of flow can be achieved by the use of a plurality of riffles.
A riflle is usually a symmetrical, such as a rectangular, deep box, provided with vertical, parallel, equally spaced webs running across the narrow dimension, the tops of which form a horizontal grid below the level of the top of the box and the lower part of each of which is connected to its neighbor to form an oblique chute, alternate chutes sloping to opposite sides. Rift'les may also talte other forms, such as cylindrical, as will be described below.
By the use of the apparatus according to the present invention, it is possible to distribute granules in a manner indepen' dent of granule size and wind, and the output from the divider can be bafiled for randomized broadcast application or led into a plurality of coulters. The apparatus is suitable for use on an agricultural vehicle traversing rough ground.
Accordingly the present invention is for an apparatus for the distribution of granules or particles which comprises a cascade of riffles, means for the supply of granules to the first riffle of the cascade which divides the supply of granules into at least two streams, means for passing the said streams from the first riffle into at least two subsidiary ritiles of the cascade, optionally means for passing the streams from the said subsidiary riffles into at least one further series of riffles, and means for passing the streams from the terminal rifiles of the cascade to a distribution means.
To ensure equal and randomized division it is necessary that the granules should be fed to the center of the riffle, and desirably the granules impinge on and are scattered from one sidewall before falling on to the dividing floor.
In the cascade of riffles, the primary feed goes into the top riffle from which it emerges in at least two equal streams. Each stream may be received in a funnel shaped tube and conveyed to the inlet of another riffle. In this way three riffles can divide the primary stream into four or more substreams. A further stage of four riffles enables eight equal substreams to be obtained, and so on.
Other objects and features will be made clear from the following detailed description taken together with the accompanying drawings wherein:
FIG. I is a perspective view of a one embodiment of the present invention;
FIG. 2 is a schematic illustration of the present invention;
FIGS. 2A and 2B are side and plan views, respectively, of the first riffle of FIG. 2;
FIG. 3A is a cross-sectional view of another embodiment of the present invention;
FIGS. 33 and 3C are cross-sectional. views taken along lines 3B-3B and 3C3C, respectively, of FIG. 3A;
FIG. 4 is a schematic illustration of a manner of portablizing the present invention;
FIG. 5, is a schematic view illustrating an endless movable bucket belt for use with the present invention;
FIG. 6 is a perspective view of a device for evening the flow of granules in accordance with the present invention; and
FIG. 7 is a side view of a trellis device used for adjusting the position of the riffles in accordance with the present invention.
For convenience a riffle is illustrated in the orthogonal drawing of FIG. I, in which the front part of the vertical walls of the box I have been cutaway to illustrate the construction of the divided floor 2. If granular material 3 is thrown at random into the middle of the box, it falls out to left and right in approximately equal portions in a randomized manner. If the material is poured into one end of the box, unequal division could result, and to ensure equal and randomized division it is best to feed the granules down a central inclined tube 4 as shown in FIG. I, so that they impinge on and are scattered from one sidewall 5 before falling on to the dividing floor.
The riffle is a difiicult device to construct economically from sheet material, but is very well adapted to fabrication by injection moulding. The output of each riffle is collected in a funnel unit which also can be injection-moulded, the inlet end (top) of which is mainly rectangular and adapted to fit on to the outlet of one riffle and the outlet end (bottom) of which is tubular and adapted to fit into the inlet of the next riffle. The cascade of riffles although apparently complex geometrically, is therefore very easily made up of two injection mouldings of two kinds. The manner of assembly is illustrated in FIGS. 2,
2A and 28. Since the spacing between adjacent riffles on the same level decreases from each level to the next, the funnel connectors need also to be of different length. This is achieved by inserting plain tubes inserted telescopically on to the funnel outlets and into the riffle inlets. In this way for example an 8- fold divider is made up of 7 identical riffles (A), 14 identical funnels (B) (the last seven of which could for some purposes be omitted) two tubes (C) of one length, four tubes (D) of shorter length and 8 tubes (if necessary) (F) to connect to eoulters. Lids (G) are provided to cover the tops of the riffles and clips (H) to hold the component partstogether.
The rifile gives an approximately equal division if the supply stream is wider than two compartments but less wide than the totality of compartments. The supply stream to the riffles can be a loose and diffuse one and subject to oscillation in the position of its center. A plurality of riffles is therefore satisfactory on an agricultural machine and also capable of dealing with a very wide range of rates of feed.
It is not however in principle essential that the riffle should divide the supply into two streams only. if, for example, the number of compartments in the floor is a multiple of three and the first slopes to the left, the second discharges centrally and the third slopes to the right and subsequent compartments repeat this pattern then a sufficiently broad supply stream is divided into three approximately equal streams.
Similarly division can be made into four or more streams if the riffle is made larger and its geometry more complex. A convenient means of making a more-than-three-fold riffle, with the webs running across its width, by a cylindrical box divided by radial webs into equiangular compartments, the floors of which fonn a cone within the cylinder. Each radial compartment leads at its lowest level into a vertical bore and these lead to vents in the outer wall of the cylinder. These bores, in symmetrical groups, are of different depths so that the outlet vents are at different levels, in groups. The output of these groups can be brought together to tubes the number of which is an integral factor of the total number of compartments. Thus l equal radial compartments could feed five tubes, the three compartments feeding each tube being symmetrically situated at 120 one to another. Conveniently the whole can be made by injection moulding in the form illustrated in vertical section in FIG. 3A. l-lere K shows the walls of the upper part of the cylinder, M the upper edge of one radial web N the surface of the cone where it forms the floor of one compartment and P the bore in which this terminates. Subsequent to moulding, sloping bores are drilled from one outer surface to the base of the bores P etc. The bore forming the outlet from vertical bore P is labeled Q. These outlets are made at different heights so that there might be for example, three holes terminating at one height, three at another and so on. FIGS. 38 and 3C are horizontal sections at 3B3B and 3C3C the latter being below the level of all except the deepest vertical bores. The central input is thus divided into streams issuing from the outside of the cylinder in symmetrical groups at different heights, which, when collected up into groups, are of equal volume rate. Suitable sloping gutters lead the grouped streams into the conducting tubes, C, of FIG. 2.
The final outlets may be led by flexible tubes into coulters for line distribution below the soil, may be led to soil level in lines or may be arranged to discharge their contents on to baffles in order to secure randomized broadcasting.
it will be appreciated that, in order to avoid any collection of granules within the divider-distributor mechanism, all floor parts must be sloping, preferably at least 40 to the horizontal. This means that the whole device must be rather higher than half its operational width. lts operational width is the swathe width that it is desired to cover. The device in its operational posture is therefore inconvenient for transport, but its tenuous structure enables it easily to be made foldable. The long tubes (C) can, for example, be made of flexible tube and the whole folded to a very narrow format by right angle folding about the lines XX and to approximately half height by right angle folding about the line YY.
If the leading tubes D are flexible, the distance apart of the final outlets can be adjusted over a small range, to provide different settings for line-drilling, subject to the settings being made not so wide that the tubes have inadequate slope. Conveniently for this purpose the rifi'les themselves are attached to a known trellis structure or adjustable parallel linkage mechanism which can be expanded in conventional manner by a lockable screw shaft.
For instance, as shown in FIG. 7, a screw shalt 20 has righthand threads 10a and left-hand threads Ebb thereon. A plurality of righbhand nuts and left-hand nuts Mb are screwed on threads 10a and left-hand threads llllb respectively. A plurality of arms 21 are formed into an expandable trellis and are pivoted at their centers by pins 23, which are in turn attached to nuts lllla and 11b. The ends of arms 21 are pivoted by pins 22, which are mounted for sliding movement in vertical slots 25 of vertical columns 24. A penultimate riffle 30 is attached to the upper end of one of the columns 2d. One or more bottom riffies 31 are attached to the bottom ends of the other columns 24. It will be apparent from FIG. 7 that as screw shaft 10 is rotated, nuts 11a and lib will be moved simultaneously either toward or away from the center of screw shaft 10. Accordingly, trellis 20 will be either contracted or expanded, and the position of bottom rifiles 31 will be adjusted. It is to be understood that while screw shaft 10 has been illustrated with a single penultimate rifile 30, any desired number could be accommodated. It will be understood that the desirable flexibility, both for alteration of operational swathe width and change from working to transport posture, can be obtained by flexibility of any or all of the connecting tubes C and D and final conduit tubes F. Thus, in one extreme form it can be arranged that the terminal row or riffles are as low as possible and as far apart as possible, or in the other extreme form the whole assembly of interconnecting riffles can be made as compact as possible, expansibility of final swathe widths being achieved by the expansible mounting of the final outlets, only the final tubes F being in this case flexible. Any intermediate form is of course permissible.
Folding of the assembly for convenience of transport between fields can be made more simple and complete by using a rnore-than-two-fold riffle as above described for the first dividing operation. Folding then need only take place on the simple long tubes as indicated in FIG. 4. In this figure the tubes are shown schematically only, by lines, and the riffles by intersections. If an initial division into an odd number of channels is employed, the central one and its subsidiary dividers can remain fixed. This construction involves the use of more than one design of riffle but, to compensate for this factor increasing the cost of manufacture, economy is achieved in the subsidiary two-fold riffles since these need not be so large as is necessary if they have to serve for primary division also.
It will be understood that more-than-two-fold rifiles could also be used in the second or further stages of division. Twofold division at the later stages has however the technical advantage that, by detaching the lowest row of riffles, the number of streams can be divided by two only. Detachment of the next row divides by two again. This is convenient because one may need line spacings in seed sewing covering a range from about 6 inches to 24 inches (each adjustable on the trellis mounting by about 20 percent either way). Similarly the detachable twofold riffles can enable the machine for example to sew wheat at a 5-inch line spacing, to sow beet at a 14-inch line spacing, to broadcast fertilizer and to apply granular insecticide to either side of rows of potatoes spaced 27 inches apart, all with very little modification of the main part of the machine.
A more serious problem is created by the height of the device. This is that granules must be lifted to the height of the topmost riffle. This problem is conveniently overcome by using an endless moving bucket belt to carry granules from a conveniently low hopper to the topmost riffle. This belt can at the same time carry out the metering function. It is necessary in this case to provide a device to even out the intermittent flow supplied by the buckets.
For instance, as shown in FIG. 5, an endless belt 4M) is positioned around a drive roller M and an idler roller &2. The belt may be mounted at an incline from a granule supply 43 to a hopper Ml. Around the periphery of belt 40 are fastened a suitable plurality of buckets 45. The open ends of buckets 45 are faced toward the direction of movement of belt Ml, as shown by arrow 50, so that buckets 65 will pick up granules from supply l3 and deposit them in hopper M.
A statistically equal division of the flow is secured in each riffle, quite independently of its rate of loading provided this is not excessive. The granules are moving freely when they encounter the webs of the riffles, and therefore, provided the spaces between these webs are considerably greater then the longest dimension of the largest granule, there is no danger of blocking. The device, provided it is constructed to accept, say, field beans, will perfonn equally satisfactorily with any smaller granules whatever their shape or size. Provided it is constructed to accept fertilizer granules at say, 1 ton to the acre it will distribute equally satisfactorily any smaller dosage.
It is essential for the satisfactory operation of this otherwise simple machine that the central feed mechanism should supply the dividing mechanism at a height so far above the level of the outlets that no slope is less than about 40 to the horizontal. Allowing for the fact that each rifile must involve some vertical drop, this height must be rather more than half the width of the swathe over which the output of the feed mechanism is finally distributed. It is therefore convenient to use a simple gravity feed only in cases where a narrow swathe, say 6 feet, is supplied and where no great weight of material need be carried.
For a wide swathe, the height of delivery need not be a serious disadvantage because the dividing mechanism is easily folded and because an endless chain or belt of cups or buckets or a brush-faced auguer can not only easily lift the granular material from a supply hopper at low level, but, if operated at a speed proportional to track speed, can also carry out the necessary metering function.
Cup belts are probably the most accurate devices for metering with lifting. The range of volume supply rate necessary from the heaviest dressing of fertilizers to the thinnest sowing of seeds covers about 3 liters to 2 millilitres per second. Two or three alternative belts of different cup sizes are clearly necessary, finer adjustment being made by alteration of gear ratio between land wheels and belt drive as is conventional in agricultural machinery.
The output of the cupbelt may be significantly intermittent. This can be smoothed out to a uniform flow by interposition of a device described below between the output of the belt and the receiver of the first divider.
A suitable smoothing device consists of two cones open upwards one partly within and above the other. Each cone has a small number of wedge-shaped slots in its surface, the wide ends of which are at the top and the axes of which are parallel to the generating lines of the cones. The slots of one cone alternate, in radial position, with those of the other. When an intermittent feed of granular material is introduced into the upper cone it escapes smoothly from the lower one. Provided the smoothed rate does not exceed the maximum capacity for outlet of the slots, the smooth output rate settles down quickly to the exact mean rate of intermittent input, even when the interval between input quanta is as long as several seconds. As shown in H6. 6, granules are received into upper cone 60, and flow through slots 61 therein into lower cone 62. The granules flow through slots 63 in lower cone 62 into collector cone or hopper 64.
ll. An apparatus for the distribution of granules or particles which comprises a cascade of riftles, means for the supply of granules to the first ritfle of the cascade which divides the supply of granules into at least two streams, means for passing the said streams from the first ritfle to at least two subsidiary riffles of the cascade, optionally means for passing the streams from the said subsidiary riffles to at least one further series of riffles, and means for passing the streams from the terminal riffles of the cascade to a distribution means.
2. An apparatus as claimed in claim ll wherein the ritiles are retangular boxes, each provided with at least one vertical, parallel web running across the narrow dimension to form a horizontal grid having equally spaced apertures below the level of the top of the box, the lower part of each web being connected to its neighboring webs or walls to form an oblique chute.
3. An apparatus as claimed in claim ll wherein the riffles are cylindrical boxes, each divided by radial vertical webs into equiangular compartments, the floors of which form a cone within the cylinder, each compartment leading at its lowest level into a vertical bore which leads to a vent in the outer wall of the cylinder.
4i. An apparatus as claimed in claim ll wherein the riffles are formed by injection moulding.
5. An apparatus as claimed in claim. t wherein the floors of the riftles slope at an angle of at least 40 to the horizontal.
6. An apparatus as claimed in claim l wherein the means for passing the streams of granules from one time to another comprises a funnel-shaped tube.
'7. An apparatus as claimed in claim 6 wherein the funnel shaped tubes are injection moulded.
8. An apparatus as claimed in claim 6 wherein the upper end of each funnel shaped tube fits the outlet of the preceding rifile.
9. An apparatus as claimed in claim 6 wherein the lower end of each funnel shaped tube fits the inlet of the succeeding riffie if such exists.
110. An apparatus as claimed in claim 6 wherein the lower end of the funnel shaped tube is connected to the inlet of the succeeding riffle by a further tube.
ill. An apparatus as claimed in claim 10 wherein the further tube is flexible.
H. An apparatus as claimed in claim l wherein the first riffie is supplied with granules at a rate proportional to the track speed of a vehicle on which the apparatus is mounted.
13. An apparatus as claimed in claim ll wherein the first riffle is supplied with granules by an endless moving bucket belt moving between a hopper and the first riffle.
M. An apparatus as claimed in claim I13 wherein a device is provided to even out the fiow supplied by the buckets.
115. An apparatus as claimed in claim M wherein the device comprises two cones having their open ends upwards and wedge-shaped slots in their surfaces with the wide ends of their slots uppermost and the axes of the slots being parallel with the generating lines of the cones, the uppermost cone being partly within the lower.
16. An apparatus as claimed in claim 1 wherein the terminal riffles are connected to the discharge means by flexible tubes.
117. An apparatus as claimed in claim ll wherein the terminal riffles are mounted on an expandable trellis means.
lltl. An apparatus as claimed in claim l7 wherein the trellis means is expandable by means of a lockable screw shaft.
119. .An apparatus as claimed in claim 1 wherein the discharge means are mounted on an expandable trellis means.
20. An apparatus as claimed in claim l9, wherein the trellis means is expandable by means of a lockable screw shaft.