EP0557468A1 - Granule dispensing apparatus - Google Patents

Abstract

The invention relates to a manual pellet dispenser and essentially comprises a housing (11) provided with a tubular extension (14) supporting an electrically driven disc. The granules are fed from a reservoir to the rotary disc through a dosing control (27). The rotary disc (21) comprises curved straight walls (21a) arranged so as to cause the displacement towards the edge of the disc of the granules supplied at the center of the rotary disc with increasing radial acceleration. The apparatus may include a cover (22) surrounding the rotating disc (21) so as to limit the distribution of the granules to a specific arc or to arcs determined by the axis of rotation of the disc (21).

Description

"GRA ULE DISPENSING APPARATUS"

The present invention relates to granule dispensing apparatus and, more particularly, to an apparatus for dispensing granules for agricultural, horticultural and forestry applications.

It is well known in the art to dispense agricultural chemicals in granular form, or as granules dosed with the agricultural chemicals to be dispensed, and prior art granule dispensing apparatus fall into two quite separate and distinct classes,

(a) large scale dispensing apparatus, generally comprising a plurality of power driven applicators towed by a prime mover and intended for wide coverage in agriculture, and,

(b) hand-held dispensing apparatus, generally used for some small agricultural uses but primarily used for controlled coverage in horticultural and forestry applications.

The present invention is concerned only with hand-held granule dispensing apparatus. røiilst a great deal of attention has been given to the dispensing of agricultural chemicals in liquid form, and a very large number of devices for dispensing liquids are available, hand-held dispensing apparatus for dispensing granules, and in particular dispensing apparatus for granules less than 3 mm in diameter, have been limited in their uses and virtually all the prior art hand-held apparatus for granules have been designed for "spot" applications, wherein a small number of granules are deposited in a relatively small area.

Generally such hand-held dispensing apparatus for granules comprise a reservoir, conveniently a knapsack or backpack reservoir, which supplies the hand-held dispensing apparatus with a continuous supply of granules and a metering apparatus for metering the granules through the apparatus and delivering the metered granules to a discharge tube. In operation the granules fall, under gravity, down the discharge tube and from the open lower end of the discharge tube to the ground.

By way of one example the European Patent Publication No. 0292927A discloses a hand-held applicator in which a control unit for metering the granules through the apparatus is contained in a handle casing and discharges discrete doses of granules to a discharges tube open at its lower end. The only means for distributing the granules issuing from the discharge tube proposed in this publication is a striker plate, spaced from the open end of the discharge tube, and which offers some small random spread of the granules issuing from the discharge tube.

In another prior art dispensing apparatus a hopper discharges granules through a valve in its lower regions, the valve is operated manually by rotating a lever and the granules fall freely from the valve outlet at a rate depending upon the rate at which the handle is rotated.

Spinning disc applicators have been proposed for dispensing agricultural chemicals as liquids but granules, particularly granules less than 3 mm, have only a small area of contact with such a spinning disc and develop very little velocity at the peripheral edge of the disc.

The present invention seeks to provide a hand-held granules dispensing apparatus capable of affording a controllable distribution pattern for the granules.

According to the present invention there is provided a hand-held granules displacing apparatus comprising a casing defining a handle part and an elongate member extending from said casing, characterised in that said casing supports a rotary arrangement comprising a rotatable disc and an electric motor for rotating said disc, a supply duct for supplying granules to said disc and a power pack, supported by said casing, for driving said electric motor.

Preferably the rotatable disc includes wall elements, equally spaced apart circumferentially of the disc, arranged to assist the centrifuging of the granules from the periphery of the disc.

In a preferred embodiment said wall elements extend only over an annular part of the outer regions of the disc and the central regions of the disc within said annular part is relatively flat.

Preferably each wall element is of arcuate configuration, at all points along the length of a wall the tangent of the curvature of the wall makes an angle with the radial direction of the disc and the angle between said tangent and said radial direction reduces towards the periphery of the disc.

In a preferred embodiment the apparatus includes a shroud, the rotatable disc is arranged to rotate within said shroud and said shroud includes at least one aperture through which granules centrifuged from the rotatable disc are discharged.

Preferably the shroud is interchangeable with shrouds of different shapes and configurations.

Preferable the shroud is interchangeable with shrouds having different aperture arrangements.

In a preferred eπ__odiment the said power pack comprises a plurality of batteries arranged in series and, conveniently the power pack is contained within the casing.

Preferably the apparatus is characterised by a valve, arranged in an open condition to allow the flow of granules through the supply duct to the rotatable disc and in a closed condition to block the supply of granules to said rotatable disc.

Preferably the apparatus is characterised by means for controlling the rate at which granules are supplied to the rotatable disc.

Preferably the apparatus is characterised in that said means for controlling the rate at which granules are supplied to the rotatable disc includes means for varying the rate at which said granules are supplied to the rotatable disc.

In a preferred eπ__odiment the apparatus is characterised by a switch for connecting and disconnecting the electric motor with the power pack.

Preferably the apparatus includes electrical conductors between the power pack, the said switch and the electric motor, said conductors being substantially contained within the said casing and the said elongate element.

In a preferred eπώodiment the apparatus is characterised by means interconnecting the supply of granules with the supply of power to the electric motor and said means are arranged to allow the supply of granules to the rotatable disc only whilst said disc is rotating.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Fig. 1 shows a hand-held granules dispensing apparatus in accordance with the invention with the rotary arrangement shown in cross-section.

Fig. 2 shows, in perspective view, a metering arrangement suitable for use with the apparatus illustrated in Fig. 1.

Fig. 3 shows, in perspective view, one form of shroud for use with the apparatus illustrated in Fig. 1 and,

Fig. 4 shows, in perspective view, a spinning disc arrangement suitable for use with the apparatus illustrated in Fig. 1.

The apparatus illustrated in Fig. 1 generally comprises a casing 11 defining a hand-grip part 12, an extension part 13 and an extension part 14.

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The extension part 13 rigidly supports a power pack 15 of tubular form, containing three electrical batteries 16a, 16b and 16c_, arranged in series, and the end of power pack 15 remote from extension 13 is closed by a cap 17.

A tubular element 18 extends from the extension part 14 and supports a plate 19 remote from the casing 11.

The plate 19 supports an electric motor 20 arranged to rotate a disc 21 supported beneath the plate 19. A shroud 22 defines a cylindrical wall 22a_ sτ_troundiι_g the rotatable disc 21 and a bottom 22b_ for the chamber containing the rotatable disc 21.

An electrical conductor 23 extends from the positive end of the assembly of batteries 16a, 16b and 16c to the electric motor 20 via a switch 24, in the handle part 12, and an actuating button 24a for switch 24 extends through an aperture 12a in the end of handle part 12 remote from extension parts 13 and 14. The positive conductor 23 extends from switch 24 back through handle part 12 and extension 14 to the bore of the tubular element 18 and therefrom through an aperture 18a_^ in the side wall of the tubular element 18 to the electric motor 20.

A negative conductor 25 extends from the motor 20 through the aperture 18a, along the bore of tubular element 18, through extensions 13 and 14, and along the power pack 15 to the negative end of the assembly of batteries 16j , 16_b, and 16c-

The switch 24 may be a pressure switch, which only closes to extend power to the motor 20 whilst the actuating button 24JΪ is depressed, or the switch may comprise a flip- over switch of the type which switches between its "on" and "off" positions each time the actuating button 24a is pressed. A flexible duct 26 extends from a reservoir (not shown) for the granular material to be dispensed and said duct 26 extends through the casing 11, through a bore 18b in tubular element 18, down the bore of the element 18 and through an aperture 19a in the plate 19 so as to open below the plate 19 and above the rotatable disc 21.

A manual switch 27 is inserted into the flexible duct 26 adjacent the casing 11 and serves to control the flow rate of granules through the duct 26 downstream of the switch 27. That face of the switch 27, from which an actuating element 27a for the switch 27 projects, conveniently includes a metering scale by which the position of the actuating member 27a can be adjusted from the closure position to define a selected rate of discharged for granules through the switch 27.

As will be seen from Fig. 1 the tubular element 18 is secured to the plate 19 at an angle of some 30 to 45 degrees, whereupon granules falling from the open end of flexible duct 26 are directed towards the central regions of the disc 21.

The disc 21 is of generally circular configuration with four walls 21a upstanding from its upper surface. The walls 21a are equally spaced apart circumferentially about the upper surface of the disc 21 and each wall 21a extends from a location spaced from the central axis of the disc 21 to the peripheral edge of the disc 21. In axial view of disc 21 the walls 21a are of arcuate configuration, at all points along each wall 21a the tangent of the curvature of the wall 21a makes an angle with the radial direction of the disc 21 and the angle between the tangent and said radial direction reduces towards the periphery of the disc, whereby the granules are accelarated towards the edge of the disc 21.

The granule dispensing apparatus described above is operated as follows.

With the switch 27 in closure condition, to prevent the flow of granules therethrough, the granules reservoir (not shown) is charged with granules to be dispensed and the device is ready for use.

The operator will hold the device in one hand, gripping the hand part 12, and the weight of the power pack 15 with its batteries substantially counter-balances the weight of the assembly on the lower end of the tubular element 18 so that, in a natural position for the operator's hand, the rotatable disc 21 lies substantially horizontal and the bottom 22b of the shroud 22 is spaced above ground level.

To initiate distribution the operator first depresses actuating switch 25a in the free end of handle 12 to actuate electric motor 20 and cause disc 21 to rotate. When disc 21 is rotating at substantially uniform speed valve 27 is then opened, to the desired flow rate of granules, and granules flow under gravity from the reservoir (not shown) down the duct 26, through the metering valve 27, into the flexible duct 26 downstream of the switch 27 and said granules are released from the open end of duct 26 above the spinniiig disc 21. The granules discharged into the central regions of the disc 21 move outwardly therefrom into contact with the leading face of a wall 21a_ and are accelerated by the wall 21a, and continuously moved radially towards the edge of the spiiming disc 21, to be centrifuged from the periphery of disc 21 substantially radially of the disc 21. The walls 21a so accelerate the granules that the granules leave the disc with a substantial velocity and are discharged through the shroud 22.

A shroud 22, suitable for use with the device illustrated in Fig. 1, is shown in Fig. 3.

The shroud 22 illustrated in Fig. 3 generally comprises a cylindrical wall 22a closed at its lower regions by the bottom 22b_ and the shroud has two diametrically opposite slot-like openings 22 and 22d therethrough. The shroud 22 may be attached to the plate 19 by cooperating screw threads or by cooperating bayonet type fittings or by a snap-on fitting or by any other means by which the shroud 22 can be detachably retained with the plate 19.

When the shroud 22 is attached to the plate 19 the space between the peripheral edge of the disc 21 and the internal surface of the cylindrical wall 22a is less than the diameter of the granules to be dispensed by the device and thus granules centrifuging from the disc 21 esςape only through the slots 22 and 22d.

Dust from the granules, and broken granules, may fall through the gap between the disc 21 and the shroud 22 and will collect in the volume defined by shroud 22 and below the disc 21. This collection of dust and broken particles can be removed by detaching the shroud 21 from the plate 19 or the bottom 22b_ of the shroud 22 may have an aperture 22e therethrough to allow the collected material to fall therethrough.

With the shroud 22 fitted, and the spinning disc 21 centrifuging granules, the shroud 22 can be circumferentially located relative to the plate 19 so that the discharge of centrifuging particles is equally to each side of the direction of travel to the hand-held applicator but it will be evident that by rotationally adjusting the position of the shroud 22 relative to the plate 19 any desired distribution pattern between a discharge of the granules to the sides and the front to rear direction, relative to the direction of displacement of apparatus, can be obtained.

Further, the shroud 22 is interchangeable with other shrouds of different shape and configuration and/or presenting different arrangements of discharge apertures and whereby any desired distribution pattern for the granules centrifuged through the shroud 22 can be obtained.

Fig. 2 shows an alternative arrangement for the valve 27 and comprising a casing 30, defined by a bottom part 30a with an upstanding cylindrical wall 30b, a metering element 31 located in the casing 30 and of such diameter as to be readily angularly displaced within said casing 30 and a top part 32 which closes the upper regions of the casing 30.

The top part 32 includes a tubular extension (not shown) to which a flexible- duct 26 extending from the reservoir (not shown) is secured and the tubular extension including a bore whereupon granules from the duct 26 can pass through the top part 32. The bottom part 30 also presents a tubular extension to which a flexible duct 26 downstream of the assembly is secured and said tubular extension has a bore 3θ open to the interior of the bottom part 30. When correctly assembled the axis of the duct 26 attached to the top part 32 is coaxial with the axis of the duct 26 attached to the bottom part 30.

The metering element 31 includes three metering apertures 31a, 31b or 31c, circumferentially spaced apart and each of which can be axially aligned with the axis of the extensions upon which the duct 26 is secured. A pin 31d upstanding from the metering element 31 extends upwardly through an arcuate slot 32,a in the top part 32, concentric with the axis of the assembly, and pin 32a projects upwardly from said top part 32, whereupon the pin 31d can be manually adjusted to bring any desired one of the metering aperture 31a_, 31b or 3l into axial alignment with the axis of the duct 26. Thus, by adjusting the position of the metering element 31 within the casing the flow of granules through the assembly can be totally blocked, or adjusted to any one of a desired three metering flow rates. Ih another arrangement for the embodiment illustrated in Fig. 1 the flexible duct 26 is split within the casing 11 and an electrically operated valve is inserted between the split ends so that the flow passage through the valve forms part of the flow passage for granules through the duct 26 to disc 21.

The electrical valve is arranged in the electrical circuit for the electric motor 20 and is arranged to open, to allow granules to flow therethrough, only when the circuit to the electric motor 20 is closed, as by depressing the actuator button 24a, and to close, to prevent the flow of granules therethrough, when the circuit for motor 20 is opened. Thus, the leakage of granules to the disc 21 whilst the disc 21 is not rotating is avoided.

In a further- eπώodiment the apparatus of Fig. 1 can include a metering arrangement, such as that described in European Patent Publication No. 0292927A, in the casing 11 and whereupon discrete measured doses of granules can be supplied to the sp__nning disc for application to, a specific area or areas of the ground to be treated.

Claims

1. A hand-held granules displacing apparatus comprising a casing defining a handle part and an elongate member extending from said casing, characterised in that said casing supports a rotary arrangement comprising a rotatable disc and an electric motor for rotating said disc, a supply duct for supplying granules to said disc and a power pack, supported by said casing, for driving said electric motor.

2. A granules dispensing apparatus according to claim 1, characterised in that the rotatable disc includes wall elements, equally spaced apart circumferentially of the disc, arranged to assist the centrifuging of the granules from the periphery of the disc.

3. A granules dispensing apparatus according to claim 2, characterised in that said wall elements^{^}extend only over an annular part of the outer regions of the disc and the central regions of the disc within said annular part is relatively flat.

4. A granules dispensing apparatus according to claims 2 or 3 characterised in that each wall element is of arcuate configuration, at all points along the length of a wall the tangent of the curvature of the wall makes an angle with the radial direction of the disc and the angle between said tangent and said radial direction reduces towards the periphery of the disc.

5. A granules dispensing apparatus according to claims 1,2,3 or 4 characterised by a shroud, and wherein the rotatable disc is arranged to rotate within said shroud and said shroud includes at least one aperture through which granules centrifuged from the rotatable disc are discharged.

6. A granules dispensing apparatus according to claim 5 characterised in that the shroud is interchangeable with shrouds of different shapes and configurations.

7. A granules dispensing apparatus according to claims 5 or 6 characterised in that the shroud is interchangeable with shrouds having different aperture arrangements.

8. A granules dispensing apparatus according to any one of the preceding claims characterised in that the said power pack comprises a plurality of batteries arranged in series.

9. A granules dispensing apparatus according to any one of the preceding claims characterised in that the power pack is contained within the casing.

10. A granules dispensing apparatus according to any one of the preceding claims characterised by a vglve, arranged in an open condition to allow the flow of granules through the supply duct to the rotatable disc and in a closed condition to block the supply of granules to said rotatable disc.

11. A granules dispensing apparatus according to any one of the preceding claims, characterised by means for controlling the rate at which granules are supplied to the rotatable disc.

12. A granules dispensing apparatus according to claim 11 characterised in that said means for controlling the rate at which granules are supplied to the rotatable disc includes means for varying the rate at which said granules are supplied to the rotatable disc.

13. A granules dispensing apparatus according to any one of the preceding claims characterised by a switch for connecting and disconnecting the electric motor with the power pack.

14. A granules dispensing apparatus according to claim 13 characterised by electrical conductors between the power pack, the said switch and the electric motor, said conductors being substantially contained within the said casing and the said elongate element.

15. A granules dispensing apparatus according to any one of the preceding claims characterised by means interconnecting the supply of granules with the supply of power to the electric motor, said- means being arranged to allow the supply of granules to the rotatable disc only whilst said disc is rotating.

16. A hand-held granules dispensing apparatus substantially as herein before described with reference to, and as illustrated in, the accompanying drawings.