GB2513928A

GB2513928A - A coulter assembly for a seeding drill

Info

Publication number: GB2513928A
Application number: GB1309979.1A
Authority: GB
Inventors: Nathan Seymour; John E Frank
Original assignee: McConnel Ltd
Current assignee: McConnel Ltd
Priority date: 2013-05-01
Filing date: 2013-06-05
Publication date: 2014-11-12
Also published as: GB201307845D0; GB201309979D0

Abstract

A coulter assembly 20 for a seed drill comprises a main frame 22 arranged to couple to an off-road vehicle, an adjustment frame 24 coupled to the main frame by an adjustment mechanism, and a plurality of coulter sub assemblies 26. Each coulter sub assembly being mounted to the main frame for individual movement and is connected to the adjustment frame via a tensioning arrangement 76; wherein movement of the main frame relative to the adjustment frame acts on the tensioning arrangement to vary the tension force. At least one of the sub assemblies may be pivotably mounted with respect to the main frame intermediate a leading and a trailing end in-use. A resilient member such as a spring may extend between the coulter sub-assembly and the adjustment frame.

Description

A Coulter Assembly For a Seeding Drill The present invention relates to a coulter assembly for a seeding drill arranged to be towed by, or mounted to, an off-road vehicle such as a tractor or the like.

Seeding drills are well known in agriculture and are used to sow various seeds. Seeding drills typically have a hopper sifting atop a coulter assembly. The coulter assembly comprises a main frame arranged to be towed by, or mounted to, an off road vehicle such as a tractor.

The coulter assembly further comprises a plurality of coulter sub-assemblies. The coulter sub-assemblies comprise an arm, which is pivotably mounted with respect to the main frame.

A coulter is attached to the arm in front of a trailing wheel, which is attached to a trailing end of the arm. A series of conduits are provided which extend between the hopper and a location intermediate of the coulter and the trailing wheel of each coulter sub-assembly.

In operation, the tractor puils the seeding drill across an area of earth, the height of the coulters is preset so as to disturb any trash in the land and form a plurality of shallow channels. A seed dispenser arranged on the hopper distributes a predetermined quantity of seeds via the conduits into each channel. The trailing wheel then compacts the earth over the seeds.

It is necessary to alter the height of the coulter and the ground force exerted by each trailing wheel depending on the type of seed to be sowed and the type of earth in which they are sowed. There have been a number of attempts to alter the ground force of the trailing wheels.

One way in which the ground force can be set is to provide a hydraulic piston on each arm.

Such an arrangement is very heavy, complex and expensive to both produce and maintain.

Such arrangements are aimed at the higher end of the market. At the lower, more economical end of the market, it is known to provide a spring extending between the coulter arm and the main frame. Prior to each sowing mission, the position of each spring is adjusted on the main frame, depending on the ground force required by each trailing wheel. Such arrangements are time consuming to operate and accessing the more centrally located springs can be difficult.

It is an object of the present invention to address the afbrementioned problems and further

improve on the prior art.

According to a first aspect of the present invention there is provided a coulter assembly fbr a seed drill, comprising; a main frame; an adjustment frame coupled to the main frame; an adjustment mechanism provided to adjust the position of the adjustment frame relative to the main frame; a plurality of coultcr sub assemblies, each having a coultcr; wherein each of the coulter sub assemblies is mounted to the main frame tbr individual movement in a first degree of freedom relative to the main frame, and is connected to the adjustment frame via a tensioning arrangement, which tensioning arrangement is configured to provide a variable tension ibrcc acting against movement of each of the couker sub assemblies inthe first degree of freedom; wherein movement of the adjustment frame relative to the main frame acts on the tensioning arrangement to vary the tension fbrce.

Preferably each of the coulter sub assemblies comprises a trailing ground contacting element spaced from the couher. The ground contacting elements may be wheels.

The provision of the adjustment mechanism allows thc ground tree of all of the trailing wheels to be set within a single operation of moving the adjustment frame with respect to the main frame. This single operation significantly reduces the operation time prior to each sowing mission. Also, adjustment on the centrally located coulter sub-assemblies is made easier since the individual adjustment is not required.

Preferably the tensioning arrangement of at least one of the coulter sub assemblies comprises a resilient member extending between the adjustment frame and coulter sub-assembly.

Preferably the resilient member is a spring-preferably a coil spring, more preferably a tension spring.

Preferably at least one of the coulter sub assemblies is pivotably mounted with respect to the main frame intermediate a leading and a trailing end in-use. Preferably the couftcr and wheel are positioned rearwardly of the pivot axis in at least one of the coulter sub assemblies in use, and the resilient member is coupled to the leading end of at least one of the coulter sub assemblies in use. In this arrangement, a tension spring will act as an adjustable suspension, in which relative movement of the main frame and adjustment frame increases spring deflection, and therefore the amount of resilient force the spring exerts on the coulter sub assembly to keep the coulter and wheel in contact with the ground in use.

If the coulter contacts any debris such as stones or the like in use, the arm will pivot and allow the eoulter to rise up over the debris and revert back to its predetermined setting by virtue of the resilient member. The tension force of the resilient member that urges the arm back to its predetermined setting is adjusted by the relative position of the adjustment frame and the main frame. For example, if the resilient member is a spring, the extension of the spring may be increased by relative movement (e.g. separation) of the frames, which increased the spring force according to Hooke's law.

The adjustment mechanism may comprise a first mechanical jack. The jack may be a screw type jack. A screw jack is relatively inexpensive to produce and maintain and is simple to operate. Alternatively the first mechanical jack may be a hydraulic jack. Hydraulic jacks are powerful and robust.

In a further alternative embodiment, the adjustment mechanism may comprise a first electrically powered jack. Electrical power is available on most agricultural vehicles and such jacks are easily controlled.

The adjustment mechanism may further comprise a second jack coupled between the main frame and the tensioning frame, wherein the jacks are arranged at opposite ends of the main frame and tensioning frame. The provision of two jacks shares the load. Further jacks may be provided intermediate the first and second jacks. Such jacks are configured to form a load path between the main frame and the adjustment frame to prevent deformation under the tension forces.

The adjustment mechanism may comprise a functional link coupled between both (or more) jacks so as to synchronise their operation. The functional link may enable the first jack to be a master jack, and the second jack to be a slave jack. In this way only one jack needs to be controlled I adjusted.

For example, the adjustment mechanism may further comprise a drive shaft coupled between both jacks so as to fbrm a master jack and a slave jack. The master jack is operable by a user with the movements of the slave jack following that of the master jack by the provision of the drive shaft. This allows fur both jacks to be operable by a user in a single operation.

The master jack may, in use, be on the driver's door side of the off-road vehicle. This makes it quickcr fur a drivcr to modifr thc ground!brcc during a sowing mission sincc hclshc docs not have to Iravel to the far side of the vehicle to make an adjustment.

The resilient member may be arranged to exert a downwards lbrce on the coulter and trailing wheel in usc. Although a comptvssion spring may be used, a tension spring is preferable since it would be less limited in upward travel of the wheel and coulter which may be required if the coulter contacts any debris in use.

Each biasing member may be arranged to exert substantially the same bias on each respective arm. This results in each coulter exerting the same fbrce into the earth, resulting in an even depth of each channel.

Thc ground thrcc cxcrtcd by thc trailing whccls is bctwccn 30 and 180 kilograms. This rangc allows fur a desired compactness to be achieved regardless of the type of seed to be sown or the type of earth that the coulter assembly can encounter. The ground fbrce exerted by each trailing wheels may be equal.

The coulter may comprise a height alteration mechanism. Such a mechanism allows the coulterheighttobesetwitlirespecttothewheel,soastopmvideagreaterdegreeof adjustment which would be advantageous considering the large number of variety of seeds and earth types which the coulter assembly would experience.

The height alteration mechanism may comprise a serrated shank extending from the couker and a detent arranged to cooperate with the serrations of the shank, and the arm to set the hcight of thc coultcr. Such an aimngcmcnt is simplc to adjust.

The main frame may comprise a plurality of struts, each arranged to couple to one of the plurality of arms. The plurality of struts may extend either fore or aft of the main frame so as to form a fore row and an aft row of coulters. Two rows of coulters are more effective at reducing blockages from trash or debris in the earth. The fore struts are arranged intermediate adjacent aft struts, in other words they alternate. This provides a zig-zag type formation of coulters between the two rows which results in an even distribution of forces on the main frame during a sowing mission.

Thc coulter tcnsion frame may further comprise a plurality of fore and aft suspension beams for suspending the biasing members therefrom, each fore suspension beam corresponding to the location of the fore struts of the main frame, and each aft suspension beam corresponding to the location of the aft struts of the main frame.

The coulter assembly may have nine coulter sub-assemblies. The nine eoulter sub-assemblies may be distributed such that the fore row has four coulter sub-assemblies and the aft row has five coulter sub-assemblies.

Adjacent coulters may be equidistantly spaced. Adjacent coulters may be separate by between 450mm and 750mm. This range is considered to be effective at dealing with trash and other debris in the earth. Adjacent coulters may be separated by about 600mm. This is considered to be the optimal separation distance.

According to a second aspect of the present invention there is provided a seed drill comprising a coulter assembly as described above, and a hopper comprising a plurality of conduits extending to each coulter sub assembly.

The present invention is best described with reference to the accompanying drawings, of which: -FIGURE 1 is a perspective view of the coulter assembly according to a first aspect of the present invention; FIGURE 2 is a partially exploded perspective view of the coulter assembly from Figure 1; FIGURE 3 is a side view of the coulter assembly from Figure 1; FIGURE 4 is an above view of the coulter assembly from Figure 1; FIGURE 5 isa similar view to figure 3 showing the kinematics of the coulter assembly being adjusted; and FIGURE 6 is a similar view to figures showing the kinematics of the coulter assembly being adjusted differently.

In the description below, reference is made to "fore" and "aft" directions. "Fore" is defined as those items which point toward an off-road vehicle when the coulter assembly is being towed. "Aft" is defined as those items which point away from an off-road vehicle when the coulter assembly is being towed. Similarly, "leading" and "trailing" are defined as directed towards and away from the off-road vehicle, respectively. Also, "above" and "below" and "rise" and "lower" are with respect to the earth while the coulter assembly is in-use.

A seeding drill comprises a coulter assembly 20 which is towed behind a cultivator (not shown). The cultivator is known in the art and comprises several digging tines spaced laterally for digging earth. The digging tines are arranged in two parallel rows, and each tine is followcd by a rcspcctivc crumbling whccl. A hopper containing seed for sowing sits on top of the cultivator. The hopper comprises a plurality of tubes extending therefrom. The hopper further comprises a dispense mechanism arranged to dispense seeds through each of the tubes at a pre-determined rate. This is done in a conventional manner. The cultivator is hitched to a tractor at its fore end, and to the coulter assembly 20 at its aft end.

With reference to Figure Ito 4, the coulter assembly 20 comprises a main frame 22, a coulter adjustment frame 24 and nine coulter sub-assemblies 26.

The main frame 22 is arranged to couple to the cultivator and follow in its path. The main frame 22 comprises an elongate post 28, nine struts 30 and a pair of mounting struts 44. The elongate post 28 is arranged substantially transverse to the direction of movement of the seeding drill, in-usc.

Each strut 30 compriscs two parts 32a, 32b. Thc parts 32a, 32b arc substantially thc same as one another. The parts 32a, 32b are elongate, off-set, parallel plates. The parts 32a, 32b have a bore 34 at a first end. The parts 32a, 32b curve downwardly to a second end and have a downward projection 36 extending therefrom. Two rods 38 join the parts 32a, 32b together at the second end so as to ensure a constant lateral separation between the parts 32a, 32b.

The second end of the strut 30 defines a pivot hole 40. The parts 32a, 32b also have an elongate hole 42 extending between the ends.

Thc mounting struts 44 arc similar in construction to the struts 30 with cach having two similar elongate, parallel, off-set parts 46a, 46b each curving downwards towards a leading end which has a downward projection 48. Rods 52 extend between the leading ends of the mounting struts 44 so as to maintain a separation distance therebetween. A bore 50 is providcd in bctwccn thc leading and trailing cnds.

The bore 34 of the struts 30 receives the elongate post 28 so as to fixedly attach the nine struts 30 thereto. The nine struts 30 are thus cantilevered from the elongate post 28. Five of the struts 30 extend in an aft direction. Four of the struts 30 extend in an opposite fore direction. The fore struts 30 are arranged intermediate the aft struts 30. The mounting struts 44 are mounted to the the elongate post 28 at the centrally located bore 50.

Thc adjustmcnt framc 24 compriscs an clongatc bar 60 and ninc suspcnsion bcams 62. Thc elongate bar 60 of the adjustment frame is arranged fore and above the elongate post 28 and is substantially parallel with respect thereto. The suspension beams 62 are made by press fitting two pieces of sheet metal together so as to form a central elongate portion terminating at a bifurcated scction at both cnds 66, 68. Thc suspension bcams 62 form downwardly bcnt triangles, when viewed from the side, having a larger and a smaller end. The larger end is provided with a bore 70. The smaller end is provided with a rod 74 extending therethrough.

An elongate hole 72 is provided in the central portion extending between each bifurcated end 66, 68. All of the suspension beams 62 are substantially the same.

The bores 70 of the suspension beams 62 receive the elongate bar 60 to fixedly cantilever the suspcnsion bcams 62 therefrom. The suspension bcams 62 arc arrangcd similar to thc struts attachcd to thc elongatc post 28 of thc main framc 22 having fivc of thc suspcnsion bcams 62 projecting aft and four of the projection beams 62 projecting fore. Each rod 74 supports a tension coil spring 76 which suspends therefrom.

The nine coulter sub-assemblies 30 each comprise an arm 90, a eoulter 92 and a trailing wheel 94. The arm 90 is elongate and comprises two parts 96a, 96b. The arm can be seen to have a leading end, a central portion and a trailing end. The leading and trailing ends diverge at either end away from the central portion. A rod 98 is provided at the leading end extending between each part 96a, 96b. In the vicinity of the central portion, a pivot pin 100 extends between each part 96a, 96b. Bolts 102 are provided at the central portion to hold the parts together 96a, 96b. A channel is provided at the central portion. A passage 104 is provided through the channel for receiving a detent 106. The diverging portion of the trailing end is arranged to support an axle for supporting the trailing wheel 94.

The coulter 92 is generally blade shaped. The eoultcr 92 has a serrated shank 110 extending therefrom. The serrated shank 110 is arranged to pass through the channel of the arm 90.

The serrations are arranged to engage with the detent 106 passing through the passage 104 50 as to set the coulter 92 at a pre-determined height.

The adjustment frame 24 and the main frame 22 are connected by a first and a second jacks 80, 82. Two brackets 78 are provided which fit around the elongate bar 60 of the adjustment frame 24 for mounting each jack 80, 82 thereto. The lower end of each jack 80,82 extends between the parts 46a, 46b of the mounting struts 44 of the main frame and arc attached thereto by bolts 84. Each jack 80, 82 extends out of the top of each bracket 78. The first jack is provided with an operating handle 86 and acts as a master jack 80. A drive shaft 88 is coupled to each jack 80, 82 so as to operatively connect them together. The second jack 82 does not have a handle and acts as a slave jack 82 by virtue of being operatively coupled to the master jack 80 by the drive shaft 88. The master jack 80 is on the driver's door side of a tractor. When the adjustment frame 24 and the main frame 22 are connected together, the coil springs 76 of the five aft directed suspension beams 62 suspend between the parts 32a, 32b of the five aft directed struts 30. The coil springs 76 of the four fore directed suspension beams 62 suspend fore of the four fore directed struts 30.

The coulter sub assemblies 28 arc connected to the main frame 22 by the pivot pins 100 being pivotably coupled to the pivot holes 40 of a respective strut. The rod 98 couples to the lower end of the coil spring 76. The coulters 92 are laterally separated from adjacent coulters 92 by about 600 millimetres. By virtue of the suspension beams 62 and the struts 30 being directed fore and aft, the coulters 92 and trailing wheels 94 of the coulter sub assemblies 26 are arranged in a zig-zag formation in two rows.

The tension in the coil springs 76 biases the leading end of the arms 90 of the coulter sub assemblies 26 upwards. The tension springs 76 lso limit upward movement of the leading end of the arms 90. The trailing wheels 94 exert a ground force on the earth. The pivot pin suspend the main frame 22 above the earth. Each coulter 92 is thus suspended at a pre-determined height with respect to the earth by the arms 90.

In operation, the off-road vehicle pulls the seeding drill across a patch of earth to be sowed.

The cultivator digs deep channels with the tines, and the crumbling wheels break up the disturbed earth. Each coulter 92 follows in the path of a respective tine and crumbling wheel pair and digs into the earth to create a shallow channel. Seeds are fed from the hopper through the conduits (not shown), whose ends are located between the coulter 92 and the trailing wheel 94, so as to deposit seeds within the channel. A ground force exerted by the trailing wheel 94 then compacts the earth on top of the seeds. If the coulters 92 experience any objects such as stones or rocks during operation the arm 90 may pivot the coulters 92 up over the objects by applying additional tension to the coil spring 76.

Depending on the t)pe of seed and the type of earth it may be desirable to either change the depth of the channel or change the amount of each compaction of earth. The height of the coulter 92 relative to the trailing wheels 94 is adjustable in two ways. Firstly, by changing the position of the detent 106 on the serrated shank 110. Secondly, by the amount of ground force exerted by the trailing wheels 94. The second of the two kinematic mechanisms is described in more detail hereinbelow.

With reference to figure 5, to increase the ground three exerted by the trailing wheels 94, an operator tums the handle 86 in a clockwise direction A. The master jack 80 extends and causes the slave jack 82 to also extend as a result of the link provided by the drive shaft 88.

The extension in the master and slave jacks 80, 82 causes the bar 60 of the adjustment frame 24 to rise in direction B and separate from the post 28 of the main frame 22. Since the suspension beams 62 are fixed to the bar 60 of the adjustment frame 24, the coil springs 27 extend and therefore the tension in the coil springs 27 increases. The trailing wheels 94 have a fixed hcight rclativc to the carth so do not pivot downwards about the pivot pin 100.

Instead, the tension force T exerted by the coil springs 76 increases (according to Hooke's law).

With reference to figure 6, to decrease the ground force exerted by the trailing wheels 94, an operator turns the handle 86 in an anti-clockwise direction A'. The master jack 80 retracts and causes the slave jack 82 to also retract as a result of the link provided by the drive shaft 88. The retraction in the master and slave jacks 80, 82 causes the bar 60 of the adjustment frame 24 to lower in dircction B' and move towards the post 28 of thc main frame 22. Since the suspension beams 62 are fixed to the bar 60 of the adjustment frame 24, the tension in the coil springs 27 decreases, and the tension force T to decrease. The trailing wheels 94 have a fixed height relative to the earth so do not move upwards about the pivot pin 100. Instead, thc ground force exertcd by thc trailing whccls 94 dccrcases.

The coulter assembly 20 described herein above provides a simple and cost effective way in which to adjust the ground force settings over a plurality of coulter sub-assemblies 26 in a single operation. This single operation significantly reduces the operation time prior to each sowing mission.

It will be appreciated that various alternatives to the aforementioned first embodiment exist.

For examplc, thc coil springs 76 may be rcplaced by any other suitable type of spring. In fact, any suitable biasing member may be incorporated instead. As an alternative to the aforementioned first embodiment, the suspension beams 62 may project downwardly beneath the fore end of the arms 90 and a compression spring may extend therebetween in order to bias the forc cnd of the arms 90 upwards and thus change thc ground forcc at the trailing wheel. This is in contrast to ising a tension spring 76 as described in the first embodiment.

The jacks 80, 82 may be replaced by any adjustment mechanism such as for cxample a hydraulic piston. Although not preferably, the master and slave jacks 80, 82 may be switched around so that the slave jack 82 is on the side of the tractor where the driver's door is. It may also be possible to have a single jack located either at one end of the coulter assembly 20 or centrally located. If a single adjustment mechanism were to be used it would have to be of sufficient strength in order to bcar the load cxcrtcd thereon.

In a further alternative embodiment the serrated shank 110 and detent 106 combination is replaced by any suitable height alteration mechanism.

The fir st embodiment of this invention includes nine couher sub-assemblies 26. The actual number of coulter sub-assemblies 26 may be changed depending on the use of the conker assembly 20. In fact, the coulter assembly 20 may include any number of a plurality of coulter sub-assemblies 26. The coulters 92 may be arranged differently than in two rows depending on the lengths of the struts 30 and suspension beams 62.

Claims

CLAIMS1. A eou.lter assembly for a seed drill, comprising; a main frame; an adjustment frame coupled to the main frame; an adjustment mechanism provided to adjust the position of the adjustment frame relative to the main frame; a plurality of coulter sub assemblies, each having a coulter; wherein each of the coulter sub assemblies is mounted to the main frame for individual movement in a fir st degree of freedom relative to the main frame, and is connected to the adjustment frame via a tensioning arrangement, which tensioning arrangement is configured to provide a variable tension force acting against movement of each of the coulter sub assemblies in the first degree of freedom; wherein movement of the adjustment frame relative to the main frame acts on the tensioning arrangement to vary the tension force.
2. The coulter assembly of claim 1, wherein each of the coulter sub assemblies comprises a trailing ground contacting element spaced from the eoulter.
3. The eoulter assembly of claim 2, wherein ground contacting elements are wheels.
4. The coulter assembly of any of claims 1 to 3, wherein the tensioning arrangement of at least one of the coulter sub assemblies comprises a resilient member extending between the adjustment frame and coulter sub-assembly.
5. The eoulter assembly of any of claims 1 to 4, wherein at least one of the coultcr sub assemblies is pivotably mounted with respect to the main frame intermediate a leading and a trailing end in-use.
6. The eoulter assembly of claim 5, wherein the eoulter and ground contacting element are positioned rearwardly of the pivot axis in at least one of the coulter sub assemblies in use.
7. The coulter assembly of claim 6, wherein the resilient member is coupled to the leading end of at least one of the coulter sub assemblies in use.
8. The coulter assembly of any preceding claim, wherein the adjustment mechanism comprises a first mechanical jack, preferably a screw jack or a hydraulic jack.
9. The coulter assembly of any of claims 1 to 7, wherein the adjustment mechanism comprises a first electrical ly powered jack.
10. The coulter assembly of claim 8 or 9 wherein the adjustment mechanism comprises a second jack coupled between the main frame and the adjustmcnt frame, wherein the first and second jacks are arranged at opposite ends of the main frame and adjustment frame.
11. The couher assembly of claim 10 wherein the adjustment mechanism further comprises a functional link coupled between both jacks so as to synchronise their operation.
12. The coulter assembly of claim 11 wherein the functional link enables the first jack to be a master jack, and the second jack to be a slave jack.
13. The coulter assembly of claim 12 wherein the master jack is, in-use, on the driver's door side of the off-road vehicle.
14. The coulter assembly of any preceding claim wherein the resilient member comprises a spring.
15. The coulter assembly of claim 14 wherein the spring is a coil spring.
16. The coulter assembly of any of claims 4 to 15 wherein the resilient member is arranged to exert a downwards force on the coulter and trailing wheel in use.
17. The coulter assembly of any of claims 4 to 16 wherein each resilient member is arranged to exert substantially the same bias on each respective arm.
18. The coulter assembly of any preceding claim wherein the ground force exerted by the trailing wheels is between 30 and I 80kg.
19. The coulter assembly of any preceding claim wherein the ground force exerted by each trailing wheels is equal.
20. The coulter assembly of any preceding claim wherein the coulter comprises a height alteration mechanism to adjust its position relative to the respective coulter sub assembly.
21. The coulter assembly of claim 20 wherein the height alteration mechanism comprises a serrated shank extending from the coulter and a detent arranged to cooperate with the serrations of the shank and the arm to set the height of the coulter.
22. The coulter assembly of any preceding claim wherein the main frame comprises a plurality of struts, each arranged to couple to one of the plurality of arms.
23. The coulter assembly of claim 22 wherein the plurality of struts extend either fore or aft of the main frame so as to form a fore and an aft row of coulters.
24. The coulter assembly of claim 23 wherein the fore struts are arranged intermediate adjacent aft struts.
25. The couher assembly of either claim 23 or claim 24 wherein the coulter tension frame further comprises a plurality of fore and aft suspension beams for suspending the biasing mcmbcr therefrom, each forc suspcnsion beams corresponding to the location of the fore struts of the main frame and each aft suspension beams corresponding to the location of the aft struts of the main frame.
26. The coulter assembly of any preceding claim wherein adjacent coulters are equidistantly spaced.
27. A seed drill comprising a eoulter assembly of any preceding claim and a hopper comprising a plurality of conduits extending to each coulter sub assembly.
28. A coulter assembly for a seed drill substantially as described herein with reference to, or in accordance with, the accompanying drawings.