GB1581529A

GB1581529A - Granular distribution apparatus

Info

Publication number: GB1581529A
Application number: GB3506676A
Authority: GB
Original assignee: Uni Drive Tractors Ltd
Current assignee: Uni Drive Tractors Ltd
Priority date: 1977-08-19
Filing date: 1977-08-19
Publication date: 1980-12-17

Description

(54) IMPROVEMENTS IN OR RELATING TO GRANULAR DISTRIBUTION APPARATUS (71) We, UNI-DRIVE TRACTORS LIMITED,, a British Company of Alpha Works, Station Road, Ampthill, Bedfordshire do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to distribution apparatus for granular material.

According to the invention there is provided distribution apparatus for granular material which comprises a hopper having a bottom region provided with a plurality of equal sized apertures arranged in a circle and located so that when the hopper is in an upright position granular material may pass under the influence of gravity from the hopper and through the apertures an agitator for granular material in the hopper located immediately adjacent the apertures, means for simultaneously and equally varying the degree of the opening of the apertures, a plurality of distribution ducts each having an open end thereof in association with one of said apertures and outside the hopper, and fluid supply means positioned with respect to the apertures and ducts so that the fluid issuing from the fluid supply means passes into the said ends of the ducts and entrains any granular material falling from the associated apertures.

The fluid supply means may be in the form of a plurality of individual nozzles each one of which directs air into an associated one of the ducts. Alternatively, the air supply means may be provided by a pair of concentric discs defining therebetween an annular passage through which fluid may be directed into the ends of the ditribution ducts.

The invention will now be described, by way of example only, with reference to the embodiments thereof illustrated in the accompanying drawings, in which: Figure 1 is a schematic sectional view of a first embodiment of the invention with certain parts omitted; Figures 2 and 3 are respectively plan and sectional views of part of the embodiment of Figure 1; Figure 4 is a schematic sectional view of a second embodiment of the invention; Figure 5 is a scrap view of a modification of the embodiments of Figures 1 and 4, on a larger scale.

Both embodiments of the invention described below relate to distribution apparatus for fertiliser material for agricultural use.

In the embodiment of Figure 1 a frame 1 supports a hopper 2 for fertiliser granules which hopper has a circular bottom plate 3 which in the upright position of the hopper is generally horizontal (as shown in Figure 1). The bottom plate 3 has a plurality of apertures 4 located around a pitch circle adjacent the radially outer periphery thereof.

Rotatable agitator means 5 is located in the bottom of the hopper to prevent any agglomeration of the granules and to ensure that granules may flow freely by gravity through the apertures in the bottom plate.

As shown in Figures 2 and 3 there is located immediately below the bottom plate 3 a second or shutter plate 6 which is coaxial with the bottom plate 3 and rotatable with respect thereto. The shutter plate 6 has a plurality of circular apertures 7 therein which correspond with the apertures 4 in the bottom plate of the hopper. The distribution plate 6 may be rotated with respect to the bottom plate by lever 8 to increase or decrease the degree of coincidence or area of aperture common to the bottom and the shutter plates and therefore to vary the amount of granular fertiliser material falling through the bottom plate from the hopper.

A plurality of distribution ducts 9 equal in number to the number of apertures 4 in the bottom plate 3 have first ends 10 thereof terminating at positions immediately adjacent to the apertures in the bottom and shutter plates. The axis at the end 10 of each duct 9 is generally perpendicular to the axis of the associated aperture in the bottom plate 3. Each open duct end 10 is formed as a frusto conical opening with the major diameter thereof adjacent the associated aperture 4.

Air supply means is located immediately below the shutter plate. In this embodiment the air supply means takes the form of a pair of disc members 11, 12 located one above the other and coaxial with the bottom plate 3. The two members 11, 12 have radially outer peripheries extending towards each other so as to provide a narrow annular exit passage around the periphery. Air emerging from this narrow exit passage is directed into the ends 10 of the distribution ducts 9. A fan (not shown) is mounted on the frame 1 and forces air into the centre chamber between the members 11, 12.

In use of the distribution apparatus described above the frame 1 is connected to a tractor and the power take off from the tractor is connected to the fan and to the agitator means 5.

When the tractor is set in motion the fan and the agitator means 5 are set in operation. The fan forces air into the air supply means and from the peripheral exit of the air supply means into the distribution ducts 9. The agitator means 5 ensures that the granular material can fall freely through the apertures 4 and 7 in the bottom plate 3 and shutter plate 6. Granular material issuing from the hopper 2 is entrained immediately in the air stream passing into the respective distribution ducts 9. Since the end 10 of each distribution duct is in the form of an induction duct there is a suction effect in the area immediately surrounding the end of the duct so that the granular material is actively drawn into respective duct 9.

The granular material passes along the distribution duct to distribution points such as broadcaster plates 13 which in the case of agricultural fertiliser apparatus would be located at spaced apart points on lateral frame extension 14.

In the second embodiment of the invention shown in Figure 4 which also illustrates part of a fertiliser distribution apparatus, a hopper 20 is provided which has a frusto conical bottom region 21 which has a reducing diameter in the downward direction.

The hopper has a bottom plate 22 which is not provided with apertures. However, the bottom region of the wall of the hopper close to the bottom plate 22 is provided with a series of apertures 23 located in a circumferential wall region coaxial with the bottom plate. A circumferential distribution band 24 is also of frusto conical con figuration complementary to that of the hopper wall region and is located in guides 25 outside the bottom plate 22 of the hopper 20. The distribution band 24 is provided with apertures (not shown) corresponding to the apertures 23 in the hopper wall region and is rotatable with respect to the hopper wall region so as to vary the degree of coincidence of the two series of apertures and the area of opening common to two coincident apertures.

Agitation means 26 are located in the bottom of the hopper to ensure that no agglomerations of granular material can occur in the bottom of the hopper and that the granular material may flow freely through the apertures under the influence of gravity.

A plurality of distribution ducts 28 equal in number to the apertures in the hopper are located around the bottom of the hopper and one duct 18 is associated with each aperture and each duct end 29 is shaped as in the first embodiment.

Immediately below the bottom plate 22 is a fan housing 30 which contains a fan 31 connectable to the power take off of a tractor. The housing includes an intake (not shown) and a plurality of outlet nozzles 32 equal in number to the number of apertures 23 and distribution ducts 28. Each outlet nozzle 32 is directed into the open duct end 29 of an associated distribution duct 28 so that air under pressure through operation of the fan is directed into the distribution duct.

In operation of the distribution apparatus described above and illustrated in Figure 4 the frame is connected to a tractor and the power take off of the tractor is operable to drive the agitator means 26 and the fan 31. Granular material falls under gravity through the apertures 23 in the bottom region of the hopper and in the distribution band 24. Air issues from the outlet nozzles 32 in the fan housing 31 and enters the distribution ducts 28 through the duct end 29. This causes air to be drawn into the duct end from the region immediately surrounding the end of the duct and the granular material is thereby drawn into the duct along with this air. The other ends of the distribution ducts are located at spaced apart points on outward extensions of the frame and above small broadcaster plates 33.

The apparatus described above provides a means of equally distributing fertiliser or seeds or other granular material into a series of air streams supplying any given number of outlets over any given working width of the apparatus within the limits of the capacity of the fan. The distribution in this way ensures an even distribution over the whole working width of an implement incorporat ing the distribution apparatus of the invention.

Figure 5 illustrates a modified form of aperture 40 for the bottom plate 3 and shutter plate 6 of the embodiment of Figures 1 to 3 and for the hopper wall region and the distribution band 24 of the embodiment of Figure 4. The aperture 40 is of elongate hexagonal form and the longitudinal ends of the aperture are formed as arcs of a circle of small radius so that in the position of minimum coincidence of two apertures a substantially circular through hole of small diameter is provided which is useful if the granular material is in the form of seeds which are required to be sown by the implement incorporating the apparatus at substantial spacings from each other.

With further reference to the question of control of flow of the granular material from the hbpper, it will be noted that this rate of flow is determined essentially by the effective size of the apertures in the bottom of the hopper. This flow rate is not substantially affected by the velocity of air issueing from the air supply means since air is drawn into the distribution ducts from the area surrounding the entire open end of the distribution ducts and such air is not, or is only to a minimal extent, obtained from the associated apertures in the bottom of the hopper.

Accordingly, there is no tendency for additional granular material to be drawn into the ducts merely by reason of changes in the air velocity.

WHAT WE CLAIM IS: 1. Distribution apparatus for granular material comprising a hopper having a bottom region provided with a plurality of equal sized apertures arranged in a circle and located so that when the hopper is in an upright position granular material may pass under the influence of gravity from the hopper and through the apertures, an agitator for granular material in the hopper located immediately adjacent the apertures, means for simultaneously and equally varying the degree of the opening of the apertures, a plurality of distribution ducts each having an open end thereof in associated with one of said apertures and outside the hopper the fluid supply means positioned with respect to the apertures and ducts so that the fluid issuing from the fluid supply means passes into the said ends of the ducts and entrains any granular material falling from the associated apertures.

2. Distribution apparatus according to claim 1, wherein said apertures are formed in a bottom plate of the hopper and said varying means comprises a shutter plate arranged for movement in a plane parallel to and close to that containing the bottom plate of-the hopper and having a series of apertures therein which coincide to a greater or lesser degree with the apertures in the bottom plate in accordance with the relative displacement of the said bottom and shutter plates.

3. Distribution apparatus according to claim 2 in which the apertures in both said plates are circular and arranged on respective pitch circles having centres lying on a common axis of relative rotation of the bottom shutter plates.

4. Distribution apparatus according to claim 1, wherein said apertures are formed in a circumferential wall region of the hopper and said varying means comprises a band arranged for movement about said wall region and having apertures therein arranged to coincide to a greater or lesser degree with the apertures in said wall region in accordance with the relative displacement of said band and said wall region.

5. Distribution apparatus according to claim 4, wherein all said apertures are circular.

6. Distribution apparatus according to claim 2 or claim 4 wherein the apertures are of elongateed form and have arcuate surfaces at their longitudinal ends whereby, when there is minimal coincidence of the respective apertures, a circular passage for granular material is provided.

7. Distribution apparatus according to any preceding claim wherein said open ends of said distribution ducts are formed as frusto conical openings with the major diameters thereof adjacent the associated apertures.

8. Distribution apparatus according to any preceding claim, wherein said fluid supply means includes a plurality of nozzles equal in number to the number of distribution ducts and arranged so that each nozzles directs fluid into an associated duct.

9. Distribution apparatus according to any one of claim 1 to 7 wherein said fluid supply means includes a pair of superposed plates defining therebetween an exit passage for fluid arranged so as to direct fluid into said distribution ducts.

10. Distribution apparatus according to any preceding claim wherein said fluid supply means includes a fan suitable for creating a supply of air under pressure.

11. Distribution apparatus according to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ing the distribution apparatus of the invention. Figure 5 illustrates a modified form of aperture 40 for the bottom plate 3 and shutter plate 6 of the embodiment of Figures 1 to 3 and for the hopper wall region and the distribution band 24 of the embodiment of Figure 4. The aperture 40 is of elongate hexagonal form and the longitudinal ends of the aperture are formed as arcs of a circle of small radius so that in the position of minimum coincidence of two apertures a substantially circular through hole of small diameter is provided which is useful if the granular material is in the form of seeds which are required to be sown by the implement incorporating the apparatus at substantial spacings from each other. With further reference to the question of control of flow of the granular material from the hbpper, it will be noted that this rate of flow is determined essentially by the effective size of the apertures in the bottom of the hopper. This flow rate is not substantially affected by the velocity of air issueing from the air supply means since air is drawn into the distribution ducts from the area surrounding the entire open end of the distribution ducts and such air is not, or is only to a minimal extent, obtained from the associated apertures in the bottom of the hopper. Accordingly, there is no tendency for additional granular material to be drawn into the ducts merely by reason of changes in the air velocity. WHAT WE CLAIM IS:

1. Distribution apparatus for granular material comprising a hopper having a bottom region provided with a plurality of equal sized apertures arranged in a circle and located so that when the hopper is in an upright position granular material may pass under the influence of gravity from the hopper and through the apertures, an agitator for granular material in the hopper located immediately adjacent the apertures, means for simultaneously and equally varying the degree of the opening of the apertures, a plurality of distribution ducts each having an open end thereof in associated with one of said apertures and outside the hopper the fluid supply means positioned with respect to the apertures and ducts so that the fluid issuing from the fluid supply means passes into the said ends of the ducts and entrains any granular material falling from the associated apertures.

11. Distribution apparatus according to

any preceding claim wherein agitator means are arranged in the bottom region of the hopper.

12. An agricultural implement including distribution apparatus according to any preceding claim and wherein said distribution ducts have other ends remote from said open ends and which are located in linearly spaced apart positions.

13. An implement according to claim 12, wherein said other ends of the distribution ducts are associated with broadcaster plates or sowing nozzles for the granular material.

14. A distribution device for granular material substantially as hereinbefore described with reference to Figures 1, 2 and 3 or Figure 4, or with reference to Figures 1, 2 and 3 or Figure 4 as modified by Figure 5, of the accompanying drawings.