AU2008202412B2 - Seed Distributor Flow Sensor - Google Patents

Abstract

-20 A seed delivery flow sensor for monitoring flow of seed and other particulate material through a delivery conduit; said seed and other material entrained in an airflow passing through said conduit; said sensor including an element rotationally reactive to said entrained seed and other material; said element comprising a baffle mounted within a tubular section of said deliver conduit; said element connected to an external indicator via a shaft extending through a wall of said conduit; said baffle biased to rotate into a non-flow indicating position when no seed or other material is entrained in said air flow.

Description

P1/001009 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A DIVISIONAL PATENT APPLICATION Invention Title: SEED DISTRIBUTOR FLOW SENSOR The invention is described in the following statement, including the best manner of performing the invention known to us: Our Ref: 072059 - 2 SEED DISTRIBUTOR FLOW SENSOR The present invention relates to seeding equipment for agricultural crops and, more particularly, to control systems for pneumatic seeders. 5 BACKGROUND With crops being grown on broad acreage, specialised seeding equipment for towing behind a tractor which seeks to minimise labour input, has seen the development of 10 multi-outlet, pneumatically driven seeders. Typically, seed is initially gravity fed from a hopper to a chamber from which it is conveyed into a main delivery duct. An air flow is introduced into the duct from a fan powered from the tractor's power take off or hydraulic system. 15 Depending on the size of the equipment, the main delivery duct may first urge the seed (now entrained in the air flow) to a primary distribution head from where it is conducted via hoses to a number of secondary distribution heads arranged at intervals along the width of the seeder 20 array. These secondary distribution heads are typically arranged at the top of a vertical delivery tube. Each secondary seed distribution head in turn has a number of outlets for connection of conduits leading to the individual seed shoes. 25 A particular problem with such multi distribution head seeders is that if any of these feed hoses or riser tubes -3 become blocked for any reason, a whole swathe of a seeded field may remain unproductive. Electronic monitoring systems are known but where these are in close contact with the flow of seeds or other entrained material, false signals due to the static electricity associated with these flows can render such in-line electronic sensing systems unreliable, It is an object of the present invention to address or at least ameliorate some of the above disadvantages. Notes 1. The term "comprising" (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of", 2. The above discussion of the prior art in the Background of the invention, is not an admission that any information discussed therein is citable prior art or part of the of the common general knowledge of persons skilled in the art in any country. BRIEF DESCRIPTION OF INVENTION Accordingly, in a first broad form of the invention, there is provided a seed delivery flow sensor for monitoring flow of seed and other particulate material through a delivery conduit; said seed and other material entrained in an airflow passing through said conduit; said sensor including an element rotationally reactive to said entrained seed and other material; said element comprising a baffle mounted within a -4 tubular section of said deliver conduit; said element connected to an external indicator via a shaft extending through a wall of said conduit; said baffle biased to rotate into a non-flow indicating position when no seed or other material is entrained in said air flow. Preferably, said conduit is a riser tube of a multi-port seed or other material distribution header. Preferably, said rotationally reactive element is a pivotable element rotationally mounted within said conduit; said pivotable element rotating between a non-flow indicating position and a flow indicating position. Preferably, said when in said non-flow indicating position is disposed substantially normal to the axis of said tubular section. Preferably, said baffle is urged into a flow indicating position by said entrained seeds and other material; said baffle disposed substantially aligned with said axis of said tubular section when a maximum entrained volume of seed and other material passes through said conduit, Preferably, said baffle is mounted to said shaft passing through said wall of said tubular section; the axis of said shaft substantially normal to the axis of said tubular section.

-5 Preferably, an indicator arm is attached to at least one end of said shaft; each said indicator arm aligned with said baffle, such that in said non-flow indicating position each said indicator arm is normal to said axis of said tubular section. Preferably, said rotationally reactive element is a paddle wheel rotationally mounted within a chamber in communication with said conduit; said paddle wheel connected to an external indicator disc via a shaft extending through side walls of said chamber. Preferably, said chamber comprises opposing spaced apart side walls; said side connected by upper, end and lower walls so as to form an enclosure with one open end; said open ,end affixed to and coincident with an opening in the side of a length of tubing. Preferably, at least portions of vanes of said paddle wheel project from said chamber into said opening so as to expose said portions to said seed and other material entrained in said airflow. Preferably, said vanes of said paddle wheel and said projection into said opening is such that rotation of said paddle wheel is dependent on impacts of said seed and other material entrained in said airflow. Preferably, said indicator disc is provided with at least one contrasting colour section; said contrasting colour section -6 adapted to indicating rotation of said indicator disc to an observer, when said paddle wheel is rotating due to impact of said seed and other material entrained in said airflow. Preferably, an electronic sensor is mounted adjacent to said disc; said electronic sensor adapted to transmission of an electronic signal when said indicator disc is rotating. Preferably, said disc is provided with at least one magnetic portion proximate the periphery of said disc; said magnetic portion adapted to induce a response current in said electronic sensor mounted adjacent to said disc. Preferably, a photo-electric sensor is mounted adjacent to said disc; said photo-electric sensor adapted to transmission of a signal when said contrasting coloured section passes said photo-electric sensor. Preferably, said electronic signal is monitored by an operator of seeder equipment incorporating said flow sensor; said signal generating an output on a display device remote from said flow sensor. Preferably, said sensor is interposed in each riser tube of a plurality of multi-port seed distribution headers. In another broad form of the invention, there is provide a method for alerting an observer to a lack of flow of seeds or other material entrained in an airflow passing through a -7 delivery conduit of a seeder; said method including the steps of: (a) mounting a rotatable element responsive to said flow of seeds and other material passing through said conduit, (b) providing said rotatable element with a flow indicator mounted to said rotatable element via a shaft extending through a wall of said conduit, and wherein said rotatable element comprises a baffle mounted within said conduit; said baffle biased to rotate into a non flow indicating position when no seed or other material is entrained in said air flow. Preferably, said flow indicator is adapted to transmit a signal to said observer. Preferably, said signal comprises a visual indication of rotation of said flow indicator by means of a change of position of said flow indicator relative said conduit. Preferably, said signal comprises an electromagnetic signal generated by a sensor mounted proximate said flow indicator. BRIEF DESCRIPTION OF DRAWINGS Embodiments of the present invention will now be described with reference to the accompanying drawings wherein: Figure 1 is a side view of a typical central seeder 5 unit and seed applicator array for towing behind a tractor (not shown), Figure 1A is a view from above of a similar seeder unit and applicator as shown in Figure 1, Figure 2 is a detailed view of a typical seed 10 distribution head atop a riser delivery tube with multiple individual conduits for delivery of seeds to seed shoes (not shown), with a flow sensor assembly according to the invention in sitn, Figures 3 and 4 are side views and end views 15 respectively of the flow sensor assembly of Figure 2, Figure 5 is an end sectioned view of the flow sensor assembly of Figures 3 and 4, Figure 6 is an end view of the flow sensor assembly of Figures 3 and 4 fitted with an electronic monitoring 20 sensor Figure 7 is a section of a riser tube and flow sensor indicator according to a further preferred embodiment of the invention, Figure 8 is a sectioned view of the riser tube of 25 Figure 7 with a flow indicator element in a non-flow indicating position, -9 Figure 9 is a sectioned view of the riser tube of Figure 8 showing the flow indicator element in a flow indicating position. 5 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Preferred Embodiment 10 With reference to Figures 1 and 1A, a seeder rig 10 adapted for towing behind a tractor 11, comprises a central metering seeder 12 and a cultivator 14, hitched to the seeder 12 and supported on multiple castor wheels 15. Central metering seeder 12 is also supported on castor 15 wheels 16 and is adapted to accept rotational power input 18 from the towing tractor's power take-off (or by means of hydraulic power supplied by the tractor) to drive a fan located in fan housing 20. Metering of seed from hopper 22 may be controlled trough a chain drive or gear train from a 20 ground wheel (not shown). Air pressure generated by the fan in housing 20 drives metered seed from below the hopper 22 via conduit 24 to a multi-port primary header 26. Flexible hoses 28 connected to each of the ports of primary header 26 lead to secondary 25 headers 30 (only one of which is visible in Figure 1) mounted at intervals along the width of cultivator 14.

- 10 Secondary headers 30 are also multi-port headers with flexible hoses 32 connected to each port leading to seed boots 34 (only one of which is visible in Figure 1). The primary header 26 and each of the secondary 5 headers 30 comprise a generally circular chamber 34 (as best seen in Figure 2), mounted to a riser tube 36. Typically, it is these feed hoses 28 or riser tubes 36, where the seed is driven vertically upwards, that blockages tend to occur. The result of such a blockage is shown in 10 Figure 1A where secondary header 30A is deprived of seed through the blockage 29 in feed hose 28A leaving a swathe of un-seeded ground 31. With reference now to Figures 2 to 5, the seed distribution flow sensor 40 of the present invention 15 comprises a short tubular section 41, which may be interposed between a riser tube 36 and a distribution header chamber 34. Mounted to the side of tubular section 40 is a paddle wheel chamber 42 comprising opposing spaced apart side walls 44 and 45 and enclosed on three sides by 20 upper wall 46, end wall 47 and lower wall 48, leaving the open end affixed to and coincident with an opening in the side of tubular section 41. Opposing side walls 44 and 45 are provided with sealed roller bearings 50 and 51, supporting a shaft 52 and 25 projecting outwardly from paddle wheel chamber 42. Mounted to the outer end 54 of shaft 52, is a lightweight indicator - 11 disc 56. Mounted to shaft 52 within paddle wheel housing 42 is a multi-vaned paddle wheel 60. The location of shaft 52 relative to the axis of tubular section 40, and the outer diameter of the multi 5 vaned paddle wheel 60, is such that the tips of vanes 62 of paddle wheel 60 project at least some way into tubular section 41. Thus entrained seed and other particulate material (not shown) driven by air flowing under pressure through tubular section 40 will impact on the tips of vanes 10 62 of paddle wheel 60 causing it, and consequently disc 56, to rotate. Preferably, the arrangement of paddle wheel 60 is such that rotation only occurs if tips of vanes 62 are impacted upon by seed or other material flowing upward in tubular 15 section 41. Lightweight disc 56 is provided with a contrasting colour segment 64. By this means an observer may readily ascertain if the discs 56 of each riser 36 to which a flow sensor 40 is fitted, are rotating, indicating proper flows 20 of seed to the headers 30. In one preferred form of a paddle wheel chamber 42, the chamber has end wall 47 shaped as a semicircle approximately centred on the axis of shaft 52. In this arrangement moreover, end wall 47 is provided with an 25 openable section or hatch (not shown) through which access may be obtained to paddle wheel 60.

- 12 Second Preferred Embodiment With reference now to Figure 6, a seed flow sensor 40 again comprises a paddle wheel housing 42 with a paddle wheel mounted in bearings 50/51 and provided with shaft 52 5 and indicator disc 56 as described for the First Preferred Embodiment above. However in this embodiment the flow sensor 40 is provided with a non-contact electronic sensor 70 mounted proximate to the periphery of indicator disc 56. Electronic sensor 70 may take any one of a number of 10 non-contact sensors, such as a proximity sensor responsive to small magnetic plates mounted to a non-ferrous indicator disc. Alternatively, electronic sensor 70 could be a photo electric sensor responsive to the contrasting colour segment of the indicator disc for example. 15 In each case electronic sensor 70 is effectively isolated from static electric charges which may build up in risers 36 and the mechanical components of seed flow sensor 40. When indicator disc 56 is rotating, each rotation generates an electric pulse in the sensor 70 (two pulses if 20 two magnetic plates for balance are used on disc 56) and these may be monitored by a remote electronic module, for example mounted in the cabin of the towing tractor. Such a system of mechanical seed flow sensors and electronic sensors communicating with a remote module, may 25 be calibrated so that, if the rate of rotation for a given seeding or fertilising operation falls below a - 13 predetermined minimum, the operator is immediately alerted and corrective measures are able to be taken. Third Preferred Embodiment In a third preferred embodiment of the present 5 invention, with reference to Figures 7, 8 and 9, tubular section 141 of a riser tube 136 is in this embodiment provided with a pivotable element 162. Pivotable element is mounted within tubular section 141 on a shaft 152 passing through the wall of tubular section 141. The axis of shaft 10 152 is normal to the axis of tubular section 141 and offset to one side as can best be seen in Figure 8. Pivotable element' 162 comprises a baffle 164 which is biased, either by suitable distribution of mass or by a spring (not shown), into a non-flow indicating position as shown in 15 Figure 8. In this position the pivotable element is disposed substantially normal to the flow of seed passing through riser tube 136. Attached to at least one end of shaft 152 is an indicator arm 168, preferably an arrow shape in line with 20 baffle 164, so that in the non-flow indicating position of Figure 8, the arrow indicator arm 168 is normal to the axis of tubular section 141. The baffle 164 of pivotable element 162 is rotationally reactive to the impact of a flow of seed 25 entrained in the air flow within riser tube 136, so that when a maximum entrained volume of seed is flowing through - 14 the tube, pivotable element assumes the position indicated in Figure 9. It will be understood that, with appropriate bias of baffle 164, the arrow indicator arm 168 may assume any position between the non-indicating position of Figure 5 8 and the maximum flow indicating position of Figure 9, thus giving a clear indication of the status of seed flow through riser tube 136. The above describes only some embodiments of the present invention and modifications, obvious to those 10 skilled in the art, can be made thereto without departing from the scope and spirit of the present invention.

Claims (23)

1. A seed delivery flow sensor for monitoring floW of seed and other particulate material through a delivery conduit; said seed and other material entrained in an airflow passing through said conduit; said sensor including an element rotationally reactive to said entrained seed and other material; said element comprising a baffle mounted within a tubular section of said deliver conduit; said element connected to an external indicator via a shaft extending through a wall of said conduit; said baffle biased to rotate into a non-flow indicating position when no seed or other material is entrained in said air flow.

2, The flow sensor of claim 1 wherein said conduit is a riser tube of a multi-port seed or other material distribution header

3. The flow sensor of claim 1 wherein said rotationally reactive element is a pivotable element rotationally mounted within said conduit; said pivotable element rotating between a non-flow indicating position and a flow indicating position.

4. The flow sensor of claim 3 wherein said baffle when in said non-flow indicating position is disposed substantially normal to the axis of said tubular section. -16

5. The flow sensor of claim 4 wherein said baffle is urged into a flow indicating position by said entrained seeds and other material; said baffle disposed substantially aligned with said axis of said tubular section when a maximum entrained volume of seed and other material passes through said conduit.

6. The flow sensor of claim 4 or 5 wherein said baffle is mounted to said shaft passing through said wall of said tubular section; the axis of said shaft substantially normal to the axis of said tubular section.

7. The flow sensor of any one of claim 4 to 6 wherein an indicator arm is attached to at least one end of said shaft; each said indicator arm aligned with said baffle, such that in said non-flow indicating position each said indicator arm is normal to said axis of said tubular section.

8. The flow sensor of claim 1 wherein said rotationally reactive element is a paddle wheel rotationally mounted within a chamber in communication with said conduit; said paddle wheel connected to an external indicator disc via a shaft extending through side walls of said chamber.

9. The flow 'sensor of claim 8 wherein said chamber comprises opposing spaced apart side walls; said side connected by upper, end and lower walls so as to form an enclosure with -17 one open end; said open end affixed to and coincident with an opening in the side of a length of tubing.

10. The flow sensor of any one of claims 8 to 9 wherein at least portions of vanes of said paddle wheel project from said chamber into said opening so as to expose said portions to said seed and other material entrained in said airflow.

11. The flow sensor of any one of claims 8 to 10 wherein said vanes of said paddle wheel and said projection into said opening is such that rotation of said paddle wheel is dependent on impacts of said seed and other material entrained in said airflow.

12. The flow sensor of any one of claims 8 to 11 wherein said indicator disc is provided with at least one contrasting colour section; said contrasting colour section adapted to indicating rotation of said indicator disc to an observer, when said paddle wheel is rotating due to impact of said seed and other material entrained in said airflow.

13. The flow sensor of any one of claims 8 to 12 wherein an electronic sensor is mounted adjacent to said disc; said electronic sensor adapted to transmission of an electronic signal when said indicator disc is rotating.

14. The flow sensor of any one of claims 8 to 13 wherein said disc is provided with at least one magnetic portion -18 proximate the periphery of said disc; said magnetic portion adapted to induce a response current in said electronic sensor mounted adjacent to said disc.

15. The flow sensor of any one of claims 8 to 14 wherein a photo-electric sensor is mounted adjacent to said disc; said photo-electric sensor adapted to transmission of a signal when said contrasting coloured section passes said photo-electric sensor.

16. The flow sensor of claim 13 or 14 wherein said electronic signal is monitored by an operator of seeder equipment incorporating said flow sensor; said signal generating an output on a display device remote from said flow sensor.

17. The flow sensor of any one of claims 13 to 15 wherein said sensor is interposed in each riser tube of a plurality of multi-port seed distribution headers.

18, A method for alerting an observer to a lack of flow of seeds or other material entrained in an airflow passing through a delivery conduit of a seeder; said method including the steps of: (a) mounting a rotatable element responsive to said flow of seeds and other material passing through said conduit, -19 (b) providing said rotatable element with a flow indicator mounted to said rotatable element via a shaft extending through a wall of said conduit, and wherein said rotatable element comprises a baffle mounted within said conduit; said baffle biased to rotate into a non-flow indicating position when no seed or other material is entrained in said air flow.

19. The method of claim 18 wherein said flow indicator is adapted to transmit a signal to said observer.

20. The method of claim 15 wherein said signal comprises a visual indication of rotation of said flow indicator by means of a change of position of said flow indicator relative said conduit.

21. The method of claim 16 wherein said signal comprises an electromagnetic signal generated by a sensor mounted proximate said flow indicator.

22. A seed flow sensor as hereinbefore described and with reference to the accompanying drawings.

23. A seed flow sensor as hereinbefore described and with reference to Figures 7, 8 and 9.