CA1121660A - Agricultural seed drills - Google Patents
Agricultural seed drillsInfo
- Publication number
- CA1121660A CA1121660A CA000342862A CA342862A CA1121660A CA 1121660 A CA1121660 A CA 1121660A CA 000342862 A CA000342862 A CA 000342862A CA 342862 A CA342862 A CA 342862A CA 1121660 A CA1121660 A CA 1121660A
- Authority
- CA
- Canada
- Prior art keywords
- frame
- discs
- springs
- arm assemblies
- container means
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01C—PLANTING; SOWING; FERTILISING
- A01C7/00—Sowing
- A01C7/20—Parts of seeders for conducting and depositing seed
- A01C7/201—Mounting of the seeding tools
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01C—PLANTING; SOWING; FERTILISING
- A01C5/00—Making or covering furrows or holes for sowing, planting or manuring
- A01C5/06—Machines for making or covering drills or furrows for sowing or planting
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01C—PLANTING; SOWING; FERTILISING
- A01C7/00—Sowing
- A01C7/20—Parts of seeders for conducting and depositing seed
- A01C7/201—Mounting of the seeding tools
- A01C7/205—Mounting of the seeding tools comprising pressure regulation means
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Environmental Sciences (AREA)
- Sowing (AREA)
Abstract
ABSTRACT
An agricultural seed drill comprises a first frame for connection to a towing vehicle, a second frame, and a pivotal connection between the two frames. Arm assemblies are independently pivotally mounted on the second frame and each arm assembly carries at least one disc and at least one roller. Front springs and rear springs acting between the arm assemblies and the second frame are disposed respectively forward of the transverse axis of the roller and rearward of the transverse axis. The springs are arranged such that the loading on the discs is substantially independent of the weight of material in a container which is supported on the second frame.
An agricultural seed drill comprises a first frame for connection to a towing vehicle, a second frame, and a pivotal connection between the two frames. Arm assemblies are independently pivotally mounted on the second frame and each arm assembly carries at least one disc and at least one roller. Front springs and rear springs acting between the arm assemblies and the second frame are disposed respectively forward of the transverse axis of the roller and rearward of the transverse axis. The springs are arranged such that the loading on the discs is substantially independent of the weight of material in a container which is supported on the second frame.
Description
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AGRICULTURAL SEED DRILLS
This invention relates to agricultural sowing of seeds by a technique of slit sowing, in which seeds are implanted in slits or narrow slots cut in the ground.
In particular the invention is concerned with apparatus (hereinafter referred to as "àpparatus of the kind set forth") for seeding ground in the use of which seeds from container means mounted on a frame assembly con-nected to a towing vehicle are delivered through tubes to slits which are cut and opened in the ground by a plurality of discs mounted on the frame assembly for rotation about generally transverse axes, roller means mounted on the frame assembly in a position rearwardly of the discs for rotation about a transverse axis being adapted to compact the ground and close the slits after seeds have been implanted therein.
There is known an apparatus of the kind set forth in which the frame assembly comprises first and second relatively movable frames, ~f which the first frame comprises a draw bar for connection to a towing vehicle, and the second frame forms a mounting for a plurality of transversely spaced, longitudinally extending, arm assemblies carrying the discs, the arm assemblies being located below the frames and being urged downwardly away from the second frame by resilient means, and a resil-ient connection being provided between the first and second frames by adjustment of which the loading applied to the discs can be varied to control penetration of the discs into the ground and the depth of the slits thus produced.
An apparatus as described in the last preceding paragraph is hereinafter referred to as an "apparatus of the particular kind set forthl'. One example of an '' :
, apparatus of the particular kind set forth is described in U.K. Patent Specification No. 1 218 785, in which the second frame is pivotally mounted on the first frame.
Front and rear compression springs are located between each of the arm assemblies and the second frame, and each arm assembly trails from a transverse shaft, carried by the second frame, to which it is pivotally connected. The angular disposition of the second frame on the first frame can be adjusted, to vary the loading on the discs, by a screw arrangemen~ to which the second frame is resiliently connected. The container means comprises both a seed box and a fertilizer box for fertilizer.
- In ~se of~a seed drill as described in Specifica-tion number 1~21~ 785 it hàs been ~fo~nd ~th~t' as`sowing . progre$se~s adjust~ents have to ~é~made in order to keep adequate~,~eight'~on'~e discs, to provide the de~s'ired penetration of t~e, ground,S whils:t` mai'ntaining sufficient w~eight~on th~.~olier m~eans for compaction'of'the ground after seeding.- - This difficulty arisës- bécause- the weight of-materi~I (seed and, optionally, fertilizer) in the container means decreases as sowing progresses, and as a result the distribution of weight on to the discs and rollers changes. The situation is complicated by the fact that the varying weight distribution also affects the loading on the towing point of a tractor towing the drill, with the result that the attitude of the tractor may vary, also to affect the loading on the discs.
It is an object of the present invention to pro-vide an apparatus of the particular kind set forth in the use of which less difficulty arises with varying weight distribution as sowing progresses.
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According to my invention in apparatus of the kind set forth the frame assembly comprises a first frame for connection to a towing vehicle, a second frame, and a pivotal connection between the two frames, the arm assemblies are independently pivotally mounted on the second frame, and each arm assembly carries at least one of the discs and at least one roller of the roller means, and the resilient means comprise front and rear springs acting between the arm assemblies and the second frame, the front springs being mounted forward of the transverse axis of the roller means and the rear springs being mounted rearward of the transverse axis of the roller means, the front and rear springs being so con-structed and arranged that the loading on the discs is substantially independent of the weight of the material in the container means which is supported on the second frame, depth control means act between said first and second frames, and means manually-operable are provided for operating said depth control means to determine the loading on said discs and the consequent penetration of said discs into the ground which remains constant irrespective of the weight of material in such contaimer means, constants for said front springs and said rear springs being chosen such that once determined by said depth control means said penetration of said discs into the ground will remain a constant for a given terrain.
The weight of the mater`ial in the container means is taken by the rollers and a draw-bar of a towing vehicle in proportions dependent upon the distance of the container means from the draw-bar and from the axis of rotation of the rollers.
The loading on the discs is substantially dependent upon a pre-load imparted to the front springs by moving the first frame angularly with respect to the second To page 3a .
``
- 1~2~
3a frame about the pivotal connection between the frames which is located at the rear ends of the frames remote from the draw-bar.
Only a single pivotal connection is provided be-tween each arm assembly and the second frame and such a To page 4 ,, .
.~ ' .
.
., . :
, ~
z.~ o connection is located at the forward end of the second frame, the arm assemblies and the second frame being otherwise unconnected apart from the provision of the front and rear springs.
The relative spring strengths are preferably chosen in accordance with the position of the container means on the second frame. It is advantageous for the rear springs to be as weak as possible so that the rollers are able to follow closely the contours of the ground.
This, in turn, dictates the strength of the front springs.
Preferably the container means is disposed on the second frame at a location such that, in a normal atti-tude of the apparatus during a sowing operation the centre of gravity of material in the container means remains substantially vertically above the transverse axis of rotation of the roller means as sowing pro-gresses.
By arranging the container means close to, or substantially vertically above, the transverse axis of rotation of the roller means ensures that a smaller proportion of the weight is taken by the draw-bar, and a larger proportion by the roller means.
There now follows a description, to be read with reference to the accompanying drawings, of an agri-cultural seed drill which illustrates the invention by way of example.
In the accompanying drawings;
Figure 1 is a diagrammatic view in side elevation of the drill in a first position of adjustment;
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`
Figure 2 is a view similar to Figure 1 but with the drill in a second position of adjustment.
The drill is constructed very similarly to that described with reference to Figures 1 to 7 of U.K.
Patent Specification number 1 218 785. The drill is an apparatus of the particular kind set forth with a frame assembly comprising a first frame 10, comprising a draw bar 12 for connection to a towing vehicle, and a second frame 14 which is pivotally mounted, at 16, on the first frame. A plurality of arm assemblies 18 (one only visible in the drawings) are located beneath the frames and are independently pivotally mounted, at 20, on the second frame, so as to trail from the pivotal mount-ings 20. Each arm assembly carries rotatably mounted ..
discs 22 and two rollers 24, one disc and one roller being mounted on each side of the arm assembly. One front spring 26 and one rear spring 28 act between each arm assembly 18 and the second frame 14, the front springs 26 being mounted in front of a common transverse axis of rotation of the rollers 24 and the rear springs 28 being mounted behind the transverse axis of the rollers. The resilient connection between the first and second frames, for adjustment of the loading ap-plied to the discs 22 in use of the drill, comprises a rotatable screw member 30 threadedly mounted in a trun-nion block 32 on the -first frame 10. The second frame 14 is secured to a second trunnion block 34 through which the screw member 30 extends. The second trunnion block 34 is freely slidable along the screw member 30 and is resiliently located between two abut-ments on the screw member by compression springs 36 and 38. By rotation of the screw member 30, the angular adjustment of the second frame 14 on the first frame 10 can be varied to vary the loading on the discs 22.
, :
1~2~ ;0 The drill comprises container means in the form of a seed box 40 mounted on the second frame 14 to contain a supply of seeds to be dispensed in use of the drill.
Means for dispensing the seeds from the seed box, and directing the seeds into slits cut in the ground by the discs 22, is constructed and arranged substantially as in the aforementioned drill described in Specification number 1 218 785.
The drill shown in the drawinys differs from the aforementioned drill described in Specification ~No. 1 218 785 in the arrangement of the front springs 26 ~' and-thé rear springs 28, and in the mounting of the arm assemblies 18 on the second frame 14.
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As shown in Figure 2 there are no pivotal mountings between the rear ends of the arm assemblies 18 and the second frame, and, apart from the front springs 26 and the rear sp~ings 28, the arm assemblies are connected to the second fra~e 14 only by the pivotal connection 20 at their forward ends. Also the spring constants of the front and rear springs 26 and 28 are selected so that the weight of the material in the container means is transferred through them to the rollers 24 and the draw-bar with substantially none of that weight being transferred to the discs. It follows therefore that the loading on the discs 22, and in consequence the pene-tration of the discs 22 in the ground during a drilling operation, is independent of the loading on the second frame 14 and is determined solely by operation of the screw member 30 to urge the frames lO and 14 relatively towards each other as shown in Figure 2, thereby pre-loading the front springs 26.
Preferably the container means is arranged on the frame assembly so that in the normal attitude of the .
l~Z.~60 drill during a sowing operation the centre of gravity of material in the container means is vertically above the transverse axis of rotation of the rollers 24 (as indi-cated by the chain-dot line 42), and will so remain as sowing progresses and the weight of material in the container means falls. As a consequence the loading from the draw bar 12 on the towing point of a towing vehicle does not vary with weight of material in the container means.
It will be appreciated that although the container means of the drill shown in the drawings is in the form of a single seed box 40, the container could take var-ious alternative forms arranged so that the centre of gravity of material therein remained vertically above the axis of the rollers 24 during a sowing operation.
For example, the container means might comprise a seed box and a separate fertilizer box, the two boxes being located on opposite sides of the axis of the rollers 24 but being balanced about the axis so that the centre of gravity of all the material in the two boxes remains vertically over the axis during sowing. Alternatively the container means could be in the form of a single box which is compartmented to accommodate more than one material.
As referred to above the springs 26 and 28 have spring constants such that the loading on the discs 22 is substantially independent of the weight of material in the container means. When a load is applied to the second frame 14 by material in the container means, some of this load is applied to the rear springs 2B. The applied load causes a compression of the rear springs 28, and accordingly the second frame is lowered at its rear end. The loading from the draw bar 12 on the towing point remaining constant, the height above the ground of :, .:
:: -: :
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1~21~ 0 the ~ront end of the draw bar can be considered to be constant. The front springs 26 are mid-way between the towing point and the rear springs 28, and accordingly a lowering of the rear end of the second frame 14 by a certain distance is accompanied by a lowering of the second frame at the front springs 26 by one half of that distance. In order that the discs 22 should not thus be lowered, which lowering (which would alter with the load in the container means) would affect the loading on the discs 22 during a sowing operation, it is necessary that the effect should be cancelled out by the tendency for the arm assemblies 18 to pivot about the axis of the rollers 24 due to the load from the springs 28. In the drill shown in the drawings, the front springs 26 are such that they will deflect 1 inch (2.54 cm.) for each 56 pounds (25.4 kg.) of loading, and the rear springs 28 are such that they will deflect 1 inch (2.54 cm.) for each 63 pounds (28.6 kg.) of loading. The distance from the axis of the rollers 24 to the front springs 26 is 36 inches (91.4 cm.) and to the rear springs 28 is 16 inches (40.6 cm.). A load of 260 pounds (118 kg) in the container means acting through vertically above the transverse axis of rotation of the rollers 24 is bàlanced by the rollers 24 and this is taken up by the rear springs 28 180 pounds (81.6 kg) and the front springs 26 80 pounds (36.4 kg).
The rear sprin~s 28 will compress 180/63 = 2.86 inches (7.55 cm) because the rear springs 28 compress an extra 2.86 inches (7.55 cm) the front springs 26 will have to compress half of this amount i.e. an extra 1.43 inches (3.75 cm) so that the same loading of 70 pounds (31.8 kg) will be maintained on the front springs 26 to keep the required depth of penetration of the discs 22. The front springs 26 with a load of 80 pounds (36.4 kg) will compress 80/56 = 1.43 inches .. . .
.: , ~ .
-~ . .
(3.75 cm). This is calculated compression required to maintain the system in equilibrium. That is, to main-tain a constant applied pressure to the front springs 26 (disc depth control) no matter what weight is applied to the frame assembly:
This is irrespective of the quantity of seed and/or fertili~er in the respective boxes. Suppose the weight were reduced to 130 pounds (59 kg). Then a load of 90 pounds (40.8 kg) on the rear spring would compress (or lower) it 90/63 = 1.43 inches (3.75 cm). To maintain the proper depth control the front springs 26 ~ould have to compress (or lower) half this amount i.e. .715 inches (1.90 cm).
Since there is a load of 40 pounds (18.2 kg) on the front springs 26 then they would each compress (or lowex) 40/56 = .715 inches (1.90 cm).
By having the weight of the seeds and/or fertiliser boxes balanced about the rollers 24 no extra weight is added to or taken from the draw-bar hitch point no matter whether the boxes are empty or full.
If the w~ight of the seed and/or fertiliser boxes is moved forward on the main frame say to half ~ay between the draw-bar hitch point and the rollers 24, then half this weight would be taken up on the draw-bar and half on the rollers 24. Depth control would still be maintained by using the same spring arrangement as above but would be influenced by the weight on the draw-bar.
This extra weight on the draw-bar could vary from nothing to 1000 pounds (454 kg) and could perhaps affect the height of the hitch point and thus the depth control of the drill.
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AGRICULTURAL SEED DRILLS
This invention relates to agricultural sowing of seeds by a technique of slit sowing, in which seeds are implanted in slits or narrow slots cut in the ground.
In particular the invention is concerned with apparatus (hereinafter referred to as "àpparatus of the kind set forth") for seeding ground in the use of which seeds from container means mounted on a frame assembly con-nected to a towing vehicle are delivered through tubes to slits which are cut and opened in the ground by a plurality of discs mounted on the frame assembly for rotation about generally transverse axes, roller means mounted on the frame assembly in a position rearwardly of the discs for rotation about a transverse axis being adapted to compact the ground and close the slits after seeds have been implanted therein.
There is known an apparatus of the kind set forth in which the frame assembly comprises first and second relatively movable frames, ~f which the first frame comprises a draw bar for connection to a towing vehicle, and the second frame forms a mounting for a plurality of transversely spaced, longitudinally extending, arm assemblies carrying the discs, the arm assemblies being located below the frames and being urged downwardly away from the second frame by resilient means, and a resil-ient connection being provided between the first and second frames by adjustment of which the loading applied to the discs can be varied to control penetration of the discs into the ground and the depth of the slits thus produced.
An apparatus as described in the last preceding paragraph is hereinafter referred to as an "apparatus of the particular kind set forthl'. One example of an '' :
, apparatus of the particular kind set forth is described in U.K. Patent Specification No. 1 218 785, in which the second frame is pivotally mounted on the first frame.
Front and rear compression springs are located between each of the arm assemblies and the second frame, and each arm assembly trails from a transverse shaft, carried by the second frame, to which it is pivotally connected. The angular disposition of the second frame on the first frame can be adjusted, to vary the loading on the discs, by a screw arrangemen~ to which the second frame is resiliently connected. The container means comprises both a seed box and a fertilizer box for fertilizer.
- In ~se of~a seed drill as described in Specifica-tion number 1~21~ 785 it hàs been ~fo~nd ~th~t' as`sowing . progre$se~s adjust~ents have to ~é~made in order to keep adequate~,~eight'~on'~e discs, to provide the de~s'ired penetration of t~e, ground,S whils:t` mai'ntaining sufficient w~eight~on th~.~olier m~eans for compaction'of'the ground after seeding.- - This difficulty arisës- bécause- the weight of-materi~I (seed and, optionally, fertilizer) in the container means decreases as sowing progresses, and as a result the distribution of weight on to the discs and rollers changes. The situation is complicated by the fact that the varying weight distribution also affects the loading on the towing point of a tractor towing the drill, with the result that the attitude of the tractor may vary, also to affect the loading on the discs.
It is an object of the present invention to pro-vide an apparatus of the particular kind set forth in the use of which less difficulty arises with varying weight distribution as sowing progresses.
.~
.... . . . .... . .
'~ .
According to my invention in apparatus of the kind set forth the frame assembly comprises a first frame for connection to a towing vehicle, a second frame, and a pivotal connection between the two frames, the arm assemblies are independently pivotally mounted on the second frame, and each arm assembly carries at least one of the discs and at least one roller of the roller means, and the resilient means comprise front and rear springs acting between the arm assemblies and the second frame, the front springs being mounted forward of the transverse axis of the roller means and the rear springs being mounted rearward of the transverse axis of the roller means, the front and rear springs being so con-structed and arranged that the loading on the discs is substantially independent of the weight of the material in the container means which is supported on the second frame, depth control means act between said first and second frames, and means manually-operable are provided for operating said depth control means to determine the loading on said discs and the consequent penetration of said discs into the ground which remains constant irrespective of the weight of material in such contaimer means, constants for said front springs and said rear springs being chosen such that once determined by said depth control means said penetration of said discs into the ground will remain a constant for a given terrain.
The weight of the mater`ial in the container means is taken by the rollers and a draw-bar of a towing vehicle in proportions dependent upon the distance of the container means from the draw-bar and from the axis of rotation of the rollers.
The loading on the discs is substantially dependent upon a pre-load imparted to the front springs by moving the first frame angularly with respect to the second To page 3a .
``
- 1~2~
3a frame about the pivotal connection between the frames which is located at the rear ends of the frames remote from the draw-bar.
Only a single pivotal connection is provided be-tween each arm assembly and the second frame and such a To page 4 ,, .
.~ ' .
.
., . :
, ~
z.~ o connection is located at the forward end of the second frame, the arm assemblies and the second frame being otherwise unconnected apart from the provision of the front and rear springs.
The relative spring strengths are preferably chosen in accordance with the position of the container means on the second frame. It is advantageous for the rear springs to be as weak as possible so that the rollers are able to follow closely the contours of the ground.
This, in turn, dictates the strength of the front springs.
Preferably the container means is disposed on the second frame at a location such that, in a normal atti-tude of the apparatus during a sowing operation the centre of gravity of material in the container means remains substantially vertically above the transverse axis of rotation of the roller means as sowing pro-gresses.
By arranging the container means close to, or substantially vertically above, the transverse axis of rotation of the roller means ensures that a smaller proportion of the weight is taken by the draw-bar, and a larger proportion by the roller means.
There now follows a description, to be read with reference to the accompanying drawings, of an agri-cultural seed drill which illustrates the invention by way of example.
In the accompanying drawings;
Figure 1 is a diagrammatic view in side elevation of the drill in a first position of adjustment;
.
`
Figure 2 is a view similar to Figure 1 but with the drill in a second position of adjustment.
The drill is constructed very similarly to that described with reference to Figures 1 to 7 of U.K.
Patent Specification number 1 218 785. The drill is an apparatus of the particular kind set forth with a frame assembly comprising a first frame 10, comprising a draw bar 12 for connection to a towing vehicle, and a second frame 14 which is pivotally mounted, at 16, on the first frame. A plurality of arm assemblies 18 (one only visible in the drawings) are located beneath the frames and are independently pivotally mounted, at 20, on the second frame, so as to trail from the pivotal mount-ings 20. Each arm assembly carries rotatably mounted ..
discs 22 and two rollers 24, one disc and one roller being mounted on each side of the arm assembly. One front spring 26 and one rear spring 28 act between each arm assembly 18 and the second frame 14, the front springs 26 being mounted in front of a common transverse axis of rotation of the rollers 24 and the rear springs 28 being mounted behind the transverse axis of the rollers. The resilient connection between the first and second frames, for adjustment of the loading ap-plied to the discs 22 in use of the drill, comprises a rotatable screw member 30 threadedly mounted in a trun-nion block 32 on the -first frame 10. The second frame 14 is secured to a second trunnion block 34 through which the screw member 30 extends. The second trunnion block 34 is freely slidable along the screw member 30 and is resiliently located between two abut-ments on the screw member by compression springs 36 and 38. By rotation of the screw member 30, the angular adjustment of the second frame 14 on the first frame 10 can be varied to vary the loading on the discs 22.
, :
1~2~ ;0 The drill comprises container means in the form of a seed box 40 mounted on the second frame 14 to contain a supply of seeds to be dispensed in use of the drill.
Means for dispensing the seeds from the seed box, and directing the seeds into slits cut in the ground by the discs 22, is constructed and arranged substantially as in the aforementioned drill described in Specification number 1 218 785.
The drill shown in the drawinys differs from the aforementioned drill described in Specification ~No. 1 218 785 in the arrangement of the front springs 26 ~' and-thé rear springs 28, and in the mounting of the arm assemblies 18 on the second frame 14.
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As shown in Figure 2 there are no pivotal mountings between the rear ends of the arm assemblies 18 and the second frame, and, apart from the front springs 26 and the rear sp~ings 28, the arm assemblies are connected to the second fra~e 14 only by the pivotal connection 20 at their forward ends. Also the spring constants of the front and rear springs 26 and 28 are selected so that the weight of the material in the container means is transferred through them to the rollers 24 and the draw-bar with substantially none of that weight being transferred to the discs. It follows therefore that the loading on the discs 22, and in consequence the pene-tration of the discs 22 in the ground during a drilling operation, is independent of the loading on the second frame 14 and is determined solely by operation of the screw member 30 to urge the frames lO and 14 relatively towards each other as shown in Figure 2, thereby pre-loading the front springs 26.
Preferably the container means is arranged on the frame assembly so that in the normal attitude of the .
l~Z.~60 drill during a sowing operation the centre of gravity of material in the container means is vertically above the transverse axis of rotation of the rollers 24 (as indi-cated by the chain-dot line 42), and will so remain as sowing progresses and the weight of material in the container means falls. As a consequence the loading from the draw bar 12 on the towing point of a towing vehicle does not vary with weight of material in the container means.
It will be appreciated that although the container means of the drill shown in the drawings is in the form of a single seed box 40, the container could take var-ious alternative forms arranged so that the centre of gravity of material therein remained vertically above the axis of the rollers 24 during a sowing operation.
For example, the container means might comprise a seed box and a separate fertilizer box, the two boxes being located on opposite sides of the axis of the rollers 24 but being balanced about the axis so that the centre of gravity of all the material in the two boxes remains vertically over the axis during sowing. Alternatively the container means could be in the form of a single box which is compartmented to accommodate more than one material.
As referred to above the springs 26 and 28 have spring constants such that the loading on the discs 22 is substantially independent of the weight of material in the container means. When a load is applied to the second frame 14 by material in the container means, some of this load is applied to the rear springs 2B. The applied load causes a compression of the rear springs 28, and accordingly the second frame is lowered at its rear end. The loading from the draw bar 12 on the towing point remaining constant, the height above the ground of :, .:
:: -: :
r ' ~
1~21~ 0 the ~ront end of the draw bar can be considered to be constant. The front springs 26 are mid-way between the towing point and the rear springs 28, and accordingly a lowering of the rear end of the second frame 14 by a certain distance is accompanied by a lowering of the second frame at the front springs 26 by one half of that distance. In order that the discs 22 should not thus be lowered, which lowering (which would alter with the load in the container means) would affect the loading on the discs 22 during a sowing operation, it is necessary that the effect should be cancelled out by the tendency for the arm assemblies 18 to pivot about the axis of the rollers 24 due to the load from the springs 28. In the drill shown in the drawings, the front springs 26 are such that they will deflect 1 inch (2.54 cm.) for each 56 pounds (25.4 kg.) of loading, and the rear springs 28 are such that they will deflect 1 inch (2.54 cm.) for each 63 pounds (28.6 kg.) of loading. The distance from the axis of the rollers 24 to the front springs 26 is 36 inches (91.4 cm.) and to the rear springs 28 is 16 inches (40.6 cm.). A load of 260 pounds (118 kg) in the container means acting through vertically above the transverse axis of rotation of the rollers 24 is bàlanced by the rollers 24 and this is taken up by the rear springs 28 180 pounds (81.6 kg) and the front springs 26 80 pounds (36.4 kg).
The rear sprin~s 28 will compress 180/63 = 2.86 inches (7.55 cm) because the rear springs 28 compress an extra 2.86 inches (7.55 cm) the front springs 26 will have to compress half of this amount i.e. an extra 1.43 inches (3.75 cm) so that the same loading of 70 pounds (31.8 kg) will be maintained on the front springs 26 to keep the required depth of penetration of the discs 22. The front springs 26 with a load of 80 pounds (36.4 kg) will compress 80/56 = 1.43 inches .. . .
.: , ~ .
-~ . .
(3.75 cm). This is calculated compression required to maintain the system in equilibrium. That is, to main-tain a constant applied pressure to the front springs 26 (disc depth control) no matter what weight is applied to the frame assembly:
This is irrespective of the quantity of seed and/or fertili~er in the respective boxes. Suppose the weight were reduced to 130 pounds (59 kg). Then a load of 90 pounds (40.8 kg) on the rear spring would compress (or lower) it 90/63 = 1.43 inches (3.75 cm). To maintain the proper depth control the front springs 26 ~ould have to compress (or lower) half this amount i.e. .715 inches (1.90 cm).
Since there is a load of 40 pounds (18.2 kg) on the front springs 26 then they would each compress (or lowex) 40/56 = .715 inches (1.90 cm).
By having the weight of the seeds and/or fertiliser boxes balanced about the rollers 24 no extra weight is added to or taken from the draw-bar hitch point no matter whether the boxes are empty or full.
If the w~ight of the seed and/or fertiliser boxes is moved forward on the main frame say to half ~ay between the draw-bar hitch point and the rollers 24, then half this weight would be taken up on the draw-bar and half on the rollers 24. Depth control would still be maintained by using the same spring arrangement as above but would be influenced by the weight on the draw-bar.
This extra weight on the draw-bar could vary from nothing to 1000 pounds (454 kg) and could perhaps affect the height of the hitch point and thus the depth control of the drill.
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Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for seeding ground comprising a frame assembly for connection to a towing vehicle, a plurality of discs mounted on said frame assembly to cut and open slits in the ground, container means for seed mounted on said frame assembly, tubes leading from said container means to deliver seeds to slits cut and opened by said discs, and roller means mounted on said frame assembly in a position rearwardly of said discs and for rotation about a transverse axis, said roller means comprising a plurality of individual rollers, said rollers being adapted to compact the ground and close slits after seeds have been implanted therein, wherein said frame assembly comprises a first frame for connection to the towing vehicle, a second frame, a pivotal connection between said first frame and said second frame, a plurality of arm assemblies, pivotal connections between said arm assemblies and said second frame arranged such that said arm assemblies are independently pivotally mounted on said second frame, each arm assembly carrying at least one of said rollers and at least one of said discs, and resilient means comprising front springs and rear springs acting between said arm assemblies and said second frame, said front springs being mounted forward of said transverse axis of said roller means and said rear springs being mounted rearwardly of said transverse axis of said roller means, said front springs, said rear springs and said arm assemblies being so constructed and arranged that the loading on said discs is substantially independent of the weight of material in said container means, and wherein depth control means act between said first and second frames, and means manually-operable are provided for operating said depth control means to determine the loading on said discs and the consequent penetration of said discs into the ground which remains constant irrespective of the weight of material in such container means, constants for said front springs and said rear springs being chosen such that once determined by said depth control means said penetration of said discs into the ground will remain a constant for a given terrain.
2. Apparatus as claimed in Claim 1, wherein only a single pivotal connection is provided between each said arm assembly and said second frame and such a pivotal connection is located at the forward end of said second frame, said arm assemblies and said second frame being otherwise unconnected apart from the provision of said front springs and said rear springs.
3. Apparatus as claimed in Claim 1, wherein the relative spring strengths are chosen in accordance with the position of said container means on said second freame.
4. Apparatus as claimed in Claim 1, wherein said container means is disposed on said second frame at a location such that, in a normal attitude of said-apparatus during a sowing operation, the centre of gravity of material in said container means remains substantially vertically above said transverse axis of said roller means as sowing progresses.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7900374 | 1979-01-05 | ||
| GB7900374 | 1979-01-05 | ||
| GB7925516 | 1979-07-21 | ||
| GB7925516 | 1979-07-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1121660A true CA1121660A (en) | 1982-04-13 |
Family
ID=26270146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000342862A Expired CA1121660A (en) | 1979-01-05 | 1980-01-02 | Agricultural seed drills |
Country Status (4)
| Country | Link |
|---|---|
| BR (1) | BR8000033A (en) |
| CA (1) | CA1121660A (en) |
| FR (1) | FR2445685A1 (en) |
| NZ (1) | NZ192436A (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1218785A (en) * | 1968-07-20 | 1971-01-13 | Samuel Moore | Improved method and means for agricultural seeding |
| FR2383602A1 (en) * | 1977-03-18 | 1978-10-13 | Litaize Serge | Tree seedling planting machine - has hydraulic jacks control depth of planting and consolidation of soil around plant regulated by signals from feeler sensors |
-
1979
- 1979-12-18 NZ NZ19243679A patent/NZ192436A/en unknown
-
1980
- 1980-01-02 CA CA000342862A patent/CA1121660A/en not_active Expired
- 1980-01-04 BR BR8000033A patent/BR8000033A/en unknown
- 1980-01-04 FR FR8000137A patent/FR2445685A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| NZ192436A (en) | 1982-03-23 |
| FR2445685A1 (en) | 1980-08-01 |
| BR8000033A (en) | 1980-09-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |