GB2154415A - Dispensers - Google Patents

Abstract

A dispenser for dispensing animal feed by weight. Feed in a hopper 1 is fed by rotating augers and paddles 8 through an aperture 9. The feed falls onto a vane 27 off axis of a weighing cylinder 25. When the combined weight of the cylinder 25 and feed outweighs counterweights 18 and 20, a pair of balance arms 16 carrying them rock, actuating a mechanism which releases the cylinder 25, allowing it to rotate under the weight of the feed. The feed falls from the cylinder 25, and the cylinder is stopped by a stopping means 35 and 28 in the correct orientation for another weighing. <IMAGE>

Description

SPECIFICATION Improvements in and relating to dispensers The invention relatesto dispensers, and especially to a dispenser for dispensing animal feed by weight.

In our British Patent Specification No. 1 586 931, there is disclosed a dispenserfor animal feed in which an oscillating device powered by a diaphragm that is exposed alternatelyto atmospheric pressure and to a partial vacuum releases feed into a hopper on one end of a balance arm. A predetermined weight of feed in the hopper causes the balance to tip, closing the port through which atmospheric air enters the vacuum system, stopping the supply of feed and actuating a cylinder and piston thattips over the hopper, dispensing the feed. A major advantage of that dipenser is that it is entirely vacuum powered, and when it is used to feed animals in a vacuum milking-parlouritcan be driven offthe existing vacuum supply.That has, however, the disadvantage that if the dispenser is to be controlled electrically then electropneumatic valves are necessary. The dispenser also has to be reset after each weighing operation by switching off thevacuumsupplyandwaitingforairto leak into the pipes.

The invention provides a dispenser comprising a rotor arranged in use to be mounted rotatably about a horizontal axis and having a plurality of surfaces extending generally radially and axially, and spaced apart circumferentially, with respect to the said axis; means for retaining the rotor in an orientation in which one ofthe said surfaces extends generally horizontally and faces upwards; means for causing material to be dispensed to fall onto the said one surface, the said one surface being so arranged that such material accumulates upon itto one side of the said axis; the rotor being released from the retaining means in operation when the weight of such accumulated material exceeds a predetermined value; the rotor being so arranged as to rotate underthe action ofthe weight of such accumulated material to permit such material to fall from it and to be stopped by the retaining means in an orientation as aforesaid.

Because at the end of each weighing operation the rotor can advance to a position in which it is ready for the next weighing operation, the interval between the end of one weighing operation and the beginning of the next need be no longerthan the time actually taken by the rotor to rotate and, because no active step has to be taken to turn the rotor, and because there is no need to turn it back after it has been emptied, both the construction and the operation ofthe dispenser are very simple, and there are very few moving parts.

The rotor may comprise a pairofend-plates perpendicuiarto the said axis and a plurality of vanes extending between the two end plates and equally spaced apartcircumferentiallyand each defining a said surface. In a dispenserfordispensing dry materials the said vanes are preferably flat and then preferably extend along radii with respect to the said axis. When the rotor is in an orientation as aforesaid the said one surface is then preferably exactly horizontal or sloping slightly upwards away from the axis. There are advantageously three said surfaces, which are preferably symmetrically positioned at least under rotation about the said axis.

The dispenser may comprise a pivotally mounted support carrying the rotor on one side of its centre of pivoting and a counterweight on the other and arranged to rock when the said predetermined weight is passed, and being so arranged that in operation the rotor is released from the retaining means in response to such rocking. The pivotally mounted support advantageously carries a counterweight the mass or position of which is adjustable to adjust the said predetermined weight. Preferably, there are a counterweightfixedly or mounted on the support, which may balance the weight ofthe rotor and any unbalanced weight on the support itself, and a counterweight slidably mounted on the support, which may balance the adjustable weight of the material.It will be appreciated that the exact balance will be affected not only by the geometry ofthe balance, rotor, and counterweightsbutalsoonthatofthe retaining means, and may be sensitive to the exact position on the rotor at which the material accumulates. Accor- dingly, if an exactly calibrated adjustment is needed, that will usually be best done by experiment.

The pivotally mounted support may comprise a pair of generally horizontal balance arms, each supporting the rotor at a respective end of its axial length, each arm being pivotable in the vertical plane in which it lies. The balance arms may be parallel to one another and perpendicularto the axis ofthe rotor, and their end portions remote from the rotorarethen advantageously connected by a fixedly mounted counterweight. The balance arms are advantageously pivotable about an axis, and may be mounted on knife-edge bearings.

The retaining means advantageously comprises a plurality of projections on the rotor, each at a circumferential position corresponding to that of a respective said surface, and meansforstopping a said projection at an orientation that corresponds to a said orientation ofthe rotor, and in operation the stopping means is then preferably removed from the path ofthe said projection to release the rotor. It is usually preferably for all of the said projectionsto occupy identical radial and axial positions, spaced apart circumferentially, so that they all describe the same annular path as the rotor rotates, and for no other part of the dispenser, except for the stopping means in its non-released condition, to occupy any part ofthat annular path.The stopping means may be a movable member with an actuator that is triggered to move it when the said predetermined weight is passed.

Instead, the stopping means may be a fixed member and the rotor may be released by movement ofthe axis of the rotor moving the path of the projections awayfrom the fixed member, especially if the rotor is carried on a pivotally mounted support as mentioned above.

In a dispenser according to the invention for dispensing free-flowing dry materials, the said means for causing material to fall onto the said one surface may comprise a hopper having an aperture at a lower po rtion th ereof, a rotatable member arranged when stationary to tend to close the aperture and when rotating to urge material from the hopperthrough the aperture, and means for rotating the rotatable member. One or more helical auger screws may be provided to urge the material in the lower portion of the hoppertowards the rotatable member, and such screws may be mounted on a common shaft with the rotatable member, which may be rotated by an electric motor.Depending on, for example, the nature of the material to be dispensed and the availabie power supplies, other means for causing material to fall onto the rotor may be used instead. Advantageously, the operation of the electric motor or other means for rotating the rotatable member is arranged to be interrupted when the rotor is released from the retaining means.

The dispenser preferably comprises a control unit responsive to the release of the rotor to stop the falling of material onto the rotor when the rotor has been released a number oftimes determined by the control means. The control unit can thus select the total quantity of material dispensed to be any desired integral multiple ofthe predetermined weight of material necessary to release the rotor, and can change that multiple between one dispensing operation and the next without any physical adjustment of the dispenser.When, for example, the dispenser is being used to dispense feed to an individual animal in a herd, flock, or the like of ani mals, the control unit may be arranged to receive information identifying the animal and to select the multiple of the predeter mined weightto give that animal a correct ration of food.

The control unit may also be responsive to the angular position of the aforementioned rotatable member ofthe means for causing material to fall. The control unit may, for example, be arrangedto count the rotations ofthe rotatable member in order to obtain a measure of the volume of material dispensed, orarrangedto stop the rotatablememberata particular angular position at which it most effectively closes off the aperture ofthe hopper.

One form of animal-feed dispenser constructed in accordance with the invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. lisa left side elevation view of the dispenser, partly in section; Fig. 2 is a front elevation view ofthe dispenser, partlyinsection; and Fig. 3 is a right-side elevation viewofthe dispenser.

Referring to the drawings, the dispenser comprises a hopperfor animal feed, indicated generally by the reference numeral 1, in the top ofthe dispenser.

Within the hopper 1, and extending across the dispenser, is a shaft 2 journalled in bearings on side walls 3 and 4 ofthe dispenser. One end ofthe shaft 2, outside the side wall 4, is connected through a gearbox 5to an electric motor 6 mounted on a bracket 7 on the side wall 4. The gearbox 5 and motor6 may be of conventional design and are not shown in detail. The shaft 2 carries at a central portion a set of paddles 8facing an aperture Sin the bottom of a front vvall of the hopper l,and helical auger blades 10 are mounted on the parts of the shaft 2 within the hopper on either side ofthe paddles.The other end of the shaft 2, outside the side wall 3, may carry a cam 11 that is arranged to actuate a switch 12, which is then mounted on the side wall, at one or more orientations ofthe shaft. The switch 12 is wired to a control unit (not shown). Baffles indicated generally by the reference numeral 13 are provided to control the flow of feed within the hopper 1.

In a lower part of the dispenser is a main shaft 15 which isjournalled at its ends in bearings mounted on front end portions of generally horizontal balance arms 16 outside the side plates 3 and 4. The balance arms 16 are pivoted approximately attheir centres on knife-edge bearings 17 fixed to the side plates 3 and 4, and carry at their rear ends a counterweight 18 extending through gaps in the side plates. On one of the balance arms 16 is a rod 19 on which afurther counterweight 20 can slide backwards or forwards or can be clamped by a bolt 21. On the main shaft 15 is a weighing cylinder indicated generally by the reference numeral 25 comprising two circularend-plates 26 and three radially and axially extending vanes 27.On one ofthe end-walls 26 of the cylinder 25 are mounted three stop-lugs 28, so positioned that when one of the vanes 27 extends horizontally backwards one of the stop-lugs is at the top of the cylinder with a vertical stop-face facing Backwards. The ho rizonta vane 27 is then drnctiy under the aperture 9 of the hopper 1. The cour.terweighv i 8 outweights the cylinder 26, the balance achieved being such that, depending on the position of the further counterweight 20, an additional weignt of a few hundred grams on the rear half ofthe cylinder 25 is needed to tip the balance, causing the counterweight 18 to rise and the cylinder 25 to sink.

The additional weight may be as little as 1 00g or as much as 1 kg for the dispenser shown, depending on the exactweights and dimensions chosen, and the balance arms, which are about 15 cm long, are held by stops (not shown) allowing the main shaft 15 to move about3 or4 cm vertically where it passes through the side walls 3 and 4. A switch 29 on the side wall 4 has its operating lever 30 engaging one ofthe balance arms 16 and detects when the balance rocks.

The cylinder 25 is held in the abovementioned position with one vane 27 extending horizontally backwards by a stop engaging the stop lug 28 at the top of the cylinder. The stop comprises a blade 35 extending horizontally with its front end adjacent to the edge ofthe end-plate 26 of the cylinder 25 and its rear end fixed to a shaft36journalled in a bearing 37 in the side wall 4 ofthe dispenser. The outer end of the shaft 36 carries a lever 38 of ferrous metal nearto one pole of an electromagnet 39, which is so positioned that if the electromagnet is activated it attracts the lever38, rotates the shaft 36, and liftthe front end of the blade 35 away from the cylinder 25. When the electromagnet39 is not active, the blade 35 rests on the end plate 26 ofthe cylinder 25 under its own weight and, by abutting the stop face ofthetop stop lug 28, prevents the cylinder from rotating in its bearings under any additional weight that may be present on the backwardly extending vane 27. A screen indicated generally by the reference numeral 40 extends vertically in a plane behind the aperture 9 ofthe hopper 1 and in front of the rearmost point of the cylinder25.An upper part 41 of the screen 40 is of rigid sheet material, spans the entire width of the dispenser between the side walls 3 and 4 and has its upper edge just below the hopper 1, where itjoins the front edge of a cover plate 42 that extends back to the rearface of the dispenser.The lower edge ofthe upper part41 is just clearofthe cylinder 25 andfrom this hangs a lower part 43 ofthe screen 40 which is made of bristles orotherstiff but flexible material, extends laterally between the two side plates 26 of the cylinder 25 and has its bottom edge ratherabovethe level ofthe main shaft 15. The screen 40 is cut away at one side to clear the blade 35 ofthe stop forthe cylinder25.

In operation, the cylinder 25 starts in the aforementioned position with one vane 27 extending horizontally backwards and one stop lug 28 resting against the blade 35, and the front ends ofthe balance arms 16 are in their uppermost positions. The hopper 1 is filled with animal feed to be dispensed.

The motor 6 is set in motion in a sense to cause the shaft 2 to rotate counter-clockwise as seen in Fig. 1.

That causes the auger blades 10 to urge the feed towards the centre of the shaft and causes the paddles 8, as they pass below the shaft 2, to push the feed forwards out ofthe aperture 9. The feed falls from the aperture 9, guided by the screen 40, onto the horizontal vane 27 ofthe cylinder 25. That increases the weight on the front ends ofthe balance arms 16 and on the rear half of the cylinder 25.

When the weight of feed on the cylinder 25 reaches the value determined by the position of the further counterweight 20, the balance arms 16 tip and the cylinder 25 sinks. Initially, the tip of the blade 35 sinks with the stop lug 28 that it engages, until the balance arms 16 reach the point at which the switch 29 is triggered and, either directly orthrough the control unit, actuates the electromagnet 39 which in turn raises the blade 35, releasing the cylinder 25. Triggering the switch 29 also stops the motor 6, interrupting the flow of feed from the aperture 9. The cylinder 25 then revolves counter-clockwise as seen in Fig. 1 undertheweight of feed on the rear vane 27, allowing the set weight of feed to fall out of the dispenser.

The cylinder 25 continues to revolve under its own momentum, the next vane 27 pushing aside the flexible lower part43 ofthe screen 40,until the next stop lug 28 is caught by the blade 35, which has been allowed to drop either automatically by the control unitorsimply because the balance arms 16 rock back as soon as the feed falls thus releasing the switch 29. If the cylinder 25 rebounds from the blade 35, the vane 27 will strike the bottom of the screen 40 squarely, and will be pushed back down into the correct position.

Unless either the control unitortheuserintervenes to stop the operation of the dispenser,the motor6 will start again when the switch 29 is released. More feed will then be dispensed onto the new vane 27, and the cycle of operations described above will be repeated.

Preferably, the number of times that the switch 29 operates is counted by the control unit and the dispenser is stopped (by preventing the motor 6 from starting again after an interruption) after a desired numberofmeasuresoffeed have been dispensed. If the cam 11 and the switch 12 are suitably arranged, the control unit may be able to stop the motor 6with the paddles 8 vertical and horizontal, as is shown in Fig. 1, that being the position in which they most effectively close offthe aperture 9.The amount of feed dispensed may be adjusted by the control unit, by changing the number of cycles of operation ofthe dispenser, to any multiple of the set weight without any adjustments to the control unit being needed.That is especially advantageous where the dispenser is being used to dispense feed to a single animal and it is desired to tailorthe amount of feed to the individual animal.The furthercounterweight20 may then be used to set the weightoffeed per cycle; it will be appreciated that a smallersetweight gives finer selection oftheweight dispensed, butthat a largernumberofcyclesmeansa larger cumulative error, and that the magnitudes of both factors will depend on the physical characteristics of the particularfeedstuff being dispensed. The further counterweight 20 may also, if necessary, be used to adjust individual dispensers exactly to a standard.

Although the operation ofthe dispenser has been described in terms of a control unitwith some calculating power, it will be appreciated that that is not of the essence of the invention, andthatthe dispenser described may be used with a control system of any desired degree ofsimplicity orsophistication. If the cam 11 and switch 12 are provided, the number of pulses from the switch will provide an indication ofthe volume offeed discharged from the hopper 1 if that is required.

Instead ofthe movable blade 35, a fixed stop may be provided from which the stop lug is released hy the downward movement of the cylinder 25. Thai of course leads to some simplification ofthe dispenser but may lead to less accurate dispensing under at least some circumstances.

Claims (11)

1. A dispenser comprising a rotorarranged in use to be mounted rotatably about a horizontal axis and having a plurality of surfaces extending generally radiallyand axially, and spaced apart circumferential- ly, with respect to the said axis; means for retaining the rotor in an orientation in which one of the said surfaces extends generally horizontally and faces upwards; means for causing material to be dispensed to fall onto the said one surface, the said one surface being so arranged that such material accumulates upon it to one side ofthe said axis; the rotor being released from the retaining means in operation when the weight of such accumulated material exceeds a predetermined value; the rotor being so arranged as to rotate underthe action of the weight of such accumulated material to permit such material to fall from it and to be stopped by the retaining means in an orientation as aforesaid.

2. A dispenser as claimed in claim 1, wherein the rotor comprises a pairofend-platesperpendicularto the said axis and a plurality of vanes extending between the two end plates and equally spaced apart circumferentially and each defining a said surface.

3. Adispenserasclaimed in claim 2, for dispens ing dry materials,wherein the said vanes are flat and extend along radii with respect to the said axis.

4. Adispenseras claimed in anyone of claims 1 to 3, comprising a pivotally mounted support carrying the rotor on one side of its centre of pivoting and a counterweight on the other and arranged to rock when the said predetermined weight is passed, and being so arranged that in operation the rotor is released from the retaining means in response to such rocking.

5. A dispenser as claimed in claim 4, wherein the pivotally mounted support carries a counterweight the mass or position of which is adjustable to adjust the said predetermined weight.

6. A dispenser as claimed in claim 5, wherein the adjustable counterweight is a weightslidably mounted on the support, and there is also a counterweight fixedly mounted on the support.

7. A dispenser as claimed in anyone of claims 1 to 6, wherein the retaining means comprises a plurality of projections on the rotor, each at a circumferential position corresponding to that of a respective said surface, and means for stopping a said projection at an orientation that corresponds to a said orientation of the rotor, and in operation the stopping means is removed from the path ofthe said projection to release the rotor.

8. A dispenser as claimed in any one of claims 1 to 7, for dispensing dry materials, wherein the said meansforcausing material to fall onto the said one surface comprises a hopper having an aperture at a lower portion thereof, a rotatable member arranged when stationaryto tend to closethe aperture and when rotating to urge material from the hopper through the aperture, and means for rotating the rotatable member.

9. A dispenser as claimed in any one of claims 1 to 8, comprising a control unit responsive to the release of the rotorto stop the falling of material onto the rotor when the rotor has been released a number of times determined by the control means.

10. A dispenser as claimed in claim 9 when dependent upon claim 8, wherein the control unit is also responsivetothe angular position ofthe rotatable member.

11. A dispenser substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.