GB2616357A

GB2616357A - Bullet for mole drainer plough

Info

Publication number: GB2616357A
Application number: GB2305886.0A
Authority: GB
Inventors: Whyles Jonathan; Whyles Malcolm
Original assignee: Agri Linc Ltd
Current assignee: Agri Linc Ltd
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2023-09-06
Anticipated expiration: 2041-08-23
Also published as: GB2616357B; GB202305886D0

Abstract

Bullet 15 comprises a body having: a first tapered portion adjacent a first end 17 comprising a front face 18; a second tapered portion 24 between the first portion and a second end 26; an attachment member for attaching the bullet to a mole drainer plough which may comprise a slot 20 and two or more holes 21; and a flat bottom face 22 extending over the entire length of the body. Sidewalls 19 of the first tapered portion have a cylindrical profile. This may provide a more stable channel yet require less power to drag the bullet through soil. A method of creating an underground channel comprising a plough and the bullet is provided. The taper angle of the second portion may be less than the taper angle of the first portion. The second portion may extend between 20% and 100% of the length of the body.

Description

Bullet for Mole Drainer Plough This application relates to a bullet for a mole drainer plough, a mole drainer plough and associated methods.

Mole drainer ploughs are used to create channels which sit at a required depth just below ground level. The channels are commonly used to assist in draining the soil by acting as a water conduit, however they may also be used to accommodate underground pipework and for other purposes. Mole drainer ploughs can be used in agriculture and in other industries such as construction.

A mole drainer plough is often pulled behind a tractor. Figure 1 shows a mole drainer plough 1 according to the prior art. The plough comprises a main body frame 2 and a mounting headstock 3 to hitch the plough to a tractor. A sharp disc wheel 4 is mounted on the frame so that, as the plough is dragged through the soil, the disc wheel cuts a narrow vertical channel. A generally vertical leg 5 trails the cutting wheel as the plough is dragged over/through the soil. The vertical leg extends downwardly from the rigid frame, below the soil surface, to follow in the slot which has just been cut by the cutting disc wheel. The skids 7 of the plough rest on the surface of the soil as the plough is dragged through the soil. A bullet 6 is located at the bottom of the vertical leg, so that when the plough is dragged through the soil the bullet cuts a channel which is generally horizontal to the soil surface. Reference numeral 8 shows a portion of the plough, which is shown in more detail in figure 2, discussed below.

There are various problems associated with mole drainer ploughs. The channels created can partially or completely collapse in on themselves. This reduces the effectiveness of the channels in draining the soil. Mole drainer ploughs frequently require powerful machines such as tractors to pull them through the soil, due to the high resistance of certain soil types and the drag from the submerged portions of the plough. The requirement for a high amount of pulling power limits their use. Mole drainer ploughs often ride upwardly out of the soil as they are dragged along. This means that the depth of the mole channel may vary, which is undesirable. To prevent this, weight can be added to the plough, but this only increases the pulling power required to drag the plough.

The bullets of mole drainer ploughs sometimes break due to the high stresses which they experience under operation, for example in heavy substrates or when they hit a submerged root or rock.

It is amongst the objects of the invention to address one or more of these problems.

In a first aspect the invention provides a bullet for a mole drainer plough comprising; an elongate body having a first end and a second end, and an attachment member for attaching the bullet to a mole drainer plough, wherein the elongate body comprises a first tapered portion adjacent the first end.

The bullet may further comprise a second tapered portion between the first tapered portion and the second end. The first tapered portion provides a sharp end which breaks through soil easily as the bullet is dragged through the soil. The second tapered portion allows the channel which is created by the displaced soil to be gradually expanded over a larger portion of the length of the bullet as it is dragged through the soil. This compacts the walls of the channel over a larger distance than mole drainers according to the prior art. This provides a more stable mole channel, yet requires less horse power to drag the bullet through the soil. The improvement in stability is thought to be at least partially achieved by fewer particles falling back into channel as a result of the gradual compaction as the bullet creates the channel.

The second tapered portion may also provide a wider bullet cross section at the point where the attachment member is located (than in a conventional cylindrically profiled bullet such as the one shown in figures 1 and 2). This provides a stronger connection to the rest of the mole drainer plough which is less liable to break. Bullets according to the prior art, for example the one shown in figure 1, were prone to snapping at the second hole from the front if the bullet hit a rock or root. The second tapered portion improves the strength and durability of the bullet, with a minimal effect on the horse power required to drag it through soil.

The second tapered portion may comprise a first cross section adjacent to the first tapered portion which tapers to a second cross section adjacent to the second end, wherein the second cross section has a larger area than the first cross section. This provides a stable mole channel, whilst only requiring a low amount of horse power to drag the bullet through the soil.

The attachment member may be a recess or protrusion for accepting part of a leg which may be attached to the mole drainer plough. Alternatively, the attachment member may be a leg which is permanently or removably connected to the bullet.

The attachment member may comprise fasteners to removably fasten the bullet to the mole drainer plough.

An angle of taper of the second tapered portion may be less than an angle of taper of the first tapered portion. This provides a more stable mole channel, whilst only requiring a low amount of horse power to drag the bullet through the soil. The lower angle of taper of the second tapered portion means that the soil is more gradually compacted, over a longer distance, that when it passed over the steep taper of the first tapered portion. Preferably, the taper angle of the first tapered portion is different to the taper angle of the second tapered portion.

These angles may be measured with respect to an axis defined by a central axis of a mole channel which is formed by the bullet as it is dragged through the soil. These angles may also be defined with respect to a bottom surface of the bullet.

The first tapered portion preferably comprises a wedge-shaped taper, which is steeper than the taper of the second tapered portion. This is so that the body of the bullet quickly reaches (over its length) an acceptable thickness before the point where the attachment member is located. Preferably the wedge-shaped taper terminates in a point, or a pointed edge.

A taper angle of first tapered portion is preferably between 25 and 45 degrees, and more preferably between 30 and 40 degrees. A taper angle of the second tapered portion is preferably between 0 and 10 degrees, and more preferably between 2 and 6 degrees. These angles may be measured with respect to an axis defined by a mole channel which is formed by the bullet as it is dragged through the soil. These angles may also be defined with respect to a bottom surface of the bullet.

The first tapered portion may comprise two regions of taper. One region may be formed by a preferably flat front face. The second region may be formed by sidewalls of the first tapered portion. The sidewalls of the first tapered portion may have generally the same taper as the taper of the second tapered portion and may have a generally cylindrical profile.

Tapers of the first and/or the second tapered portion may be straight sided, rather than curved in the direction of elongation of the bullet. This provides an improved mole channel. Sidewalls of the tapered portions may of course be curved when viewed in cross section on a plane which is perpendicular to the axis of elongation of the bullet.

The bullet may further comprise a bottom face, which is preferably flat and preferably smooth. A common problem with prior art bullets is that the bullet tends to ride up out of the ground as it is dragged. The flat bottom face provides suction which holds down the bullet as it is dragged through the soil. This is particularly useful in clay, chalk and loam soils.

Preferably the second tapered portion forms a generally tapered cylinder, only with a flat bottom face.

The flat bottom face also provides a synergistic effect with the second tapered portion to form a more consistent mole channel, resulting in fewer soil particles falling back into the channel when the implement has passed.

Preferably the flat bottom face has a constant width over its entire length.

Preferably the width of the flat bottom face is between 30 mm and 60 mm.

Preferably the flat bottom face has a constant width over the entire length of the bullet. Preferably the flat bottom face is parallel to an abutment face of the attachment member.

Preferably the flat bottom face extends over the whole length of the elongate body. Preferably the flat bottom face defines an area of between 90 and 180 cm2.

The bottom face or surface of the bullet may be arranged relative to the attachment member such that the bullet is orientated perpendicular to a support leg of the mole drainer plough when it is connected to the mole drainer plough and in a working configuration.

For avoidance of doubt the 'bottom' of the bullet is defined with respect to the orientation of the bullet when it is attached to the rest of a mole drainer plough and in a working configuration.

The taper of the second tapered portion preferably forms a continuous surface. This reduces the horse power required to pull the bullet through the soil.

The taper of the second tapered portion preferably has a constant angle of taper.

The second tapered portion preferably extends over between 20% and 90%, and more preferably 50% to 75% of the length of the elongate body.

The first tapered portion may comprise a front face. This provides a bullet which is stable when dragged through the soil. It also works with a flat bottom face of the embodiments which have that feature, to provide suction, which prevents the bullet from riding up as it is dragged through the soil.

The front face may be planar and/or flat. This provides a bullet which is stable when dragged through the soil and requires a lower amount of horse power.

The front face may have a straight bottom edge which is connected to the rest of the periphery of the front face. This provides a stable bullet and stable mole channel. The rest of the periphery of the front face may have an oval shape. This provides a stable mole channel.

The straight bottom edge of the front face may define the boundary between the front face and a bottom surface of the bullet. This provides a strong and stable bullet. The front face may have only one plane of symmetry. This improves the robustness and stability of the bullet.

A 'front face' is a part of the bullet which in use is the first part of the bullet which comes into contact with soil as the bullet is dragged through soil along an axis which is defined by the direction of elongation. A plane of symmetry of the front face may be perpendicular to a bottom face of the bullet The bullet is preferably formed of a high chromium steel.

The attachment member may comprise a slot for receiving a portion of a plough leg. It may comprise two or more holes for receiving bolts to attach the bullet to the plough leg. Preferably the attachment member comprises 4 or more holes for receiving bolts to attach the bullet to the plough leg. The slot may extend all the way through the body of the bullet, preferably from a top surface of the bullet to a bottom surface of the bullet.

Preferably the bullet is provided with a towing member for attaching an expander to the bullet adjacent to the second end of the bullet. An expander may be attached to the towing member. Preferably the expander is a generally cylindrical plug which has a cross section which is slightly larger than the cross section of the second end of the bullet.

In a second aspect of the invention there is provided a mole drainer plough comprising a bullet as described herein.

The mole drainer plough is not limited to agricultural use or the creation of mole drain channels. The mole drainer plough relates to anything which may be dragged so that the bullet forms a channel beneath the surface of the soil.

In a further aspect of the invention there is provided a method of creating an underground channel comprising the steps; providing a mole drainer plough as described herein, and pulling the mole drainer plough behind a vehicle across a soil surface such that the bullet is located below the soil surface and creates the underground channel as the mole drainer plough is pulled across the soil surface.

Preferably the underground channel is a mole drain. The method may further include the insertion of a pipe into the mole drain.

Embodiments of the invention will now be described with reference to the figures of the drawings, in which: Figure 1 shows a perspective view of a mole drainer plough according to the prior art.

Figure 2 shows a side view of the bullet attached to a leg of the mole drainer plough shown in figure 1.

Figure 3 shows a mole drainer plough according to the invention.

Figure 4 shows a side view of the bullet attached to a leg of the mole drainer plough shown in figure 3.

Figure 5 shows a perspective view the bullet attached to a leg of the mole drainer plough shown in figure 3.

Figures 6a-6c show plan, side and bottom views of a bullet according to the invention.

Figures 7a and 7b show perspective and end views respectively of a bullet according to the invention.

Figure 1 is discussed in the description above. Figure 2 shows a side view of the portion 8 of the plough shown in figure 1. The bullet 6 is attached to a leg 5 of the mole drainer plough.

The bullet has a cylindrical cross section, with a pointed front end 9. The cylindrical cross section is most easily seen in the front face 10 shown in figure 1, which has an elliptical shape. From the rear of the pointed front end 9, the sidewalls 11 which define the width of the bullet are straight. This means that the outer cross section of the bullet is generally constant until it reaches the rear end 12 of the bullet. An expander 13 is attached by a chain 14 to the rear of the bullet. The expander is dragged behind the bullet in the channel formed by the bullet. The expander has a cylindrical cross section, with a diameter which is slightly larger than the diameter of the cross section of the bullet.

Figure 3 shows a mole drainer plough according to the invention.

The features of the plough are identical to the features shown in figures 1 and 2 apart from the features of the bullet 15 and the expander 30. Figure 4 shows a side view of the portion 16 of figure 3. The bullet 15 is attached to a leg 5 of the mole drainer plough shown in figure 3. Figure 5 shows a perspective view of the portion 16 of figure 3. The bullet 15 is attached to a leg 5 of the mole drainer plough shown in figure 3.

The bullet has a recess 20 on its upper edge. The recess is a generally cuboid slot and accommodates a lower portion of the leg 5. To fix the leg to the bullet, the recess is provided with through holes 21. A fastener can be inserted through these through holes to removably attach the bullet 15 to the leg 5. Four through holes 21 are provided. They are provided in a line which is parallel to the flat bottom face 22 of the bullet.

The bullet has a flat bottom face 22 which defines a rectangular area. The bullet has a first pointed end 17. The flat bottom face 22 has a straight leading edge 23 which forms part of the first pointed end 17 of the bullet. The flat bottom surface is perpendicular to the leg 5 of the plough when it is attached to the plough.

The pointed end 17 is the leading end of the bullet when it is dragged through the soil. The width of the pointed end of the bullet tapers outwardly via a planar front face 18, so that the cross section of the bullet 15 increases with distance from the first pointed end. The front face 18 has a generally elliptical outline, apart from where it meets the straight leading edge 23. The taper over this pointed end 17 of the bullet is also formed by the sidewalls 19 between the flat front face 18 and the flat bottom face 22. The sidewalls 19 are curved with a constant radius of curvature. They taper outwardly from the leading edge 23 from a smaller diameter to a larger diameter where the front face 18 meets a second tapered portion 24 of the bullet. Where the front face 18 meets the second tapered portion 24 of the bullet there is an abrupt change in the angle of the taper. The angle of the front face 18 (whether in embodiments where the face completely planar or otherwise), with respect to the flat bottom face 22 is about 30 degrees.

The second tapered portion 24 of the bullet sits between the first pointed end 17 and a second end 26 of the bullet. It has a generally flared cylindrical taper (apart from the flat bottom face 22 and the recess 20) which increases in width with distance from the first pointed end 17. The sidewalls 25 are generally curved with a constant radius of curvature which is perpendicular to the direction of elongation of the bullet. They are preferably smooth over their length. The sidewalls 25 extend from the rear of the first pointed end 17 of the bullet, where they merge smoothly with the sidewalls 19 of the pointed end 17. The sidewalls 19 of the first pointed end and the sidewalls 25 of the second tapered portion have the same angle of taper, with respect to the axis of elongation of the bullet.

When viewed from the side, as in figure 4, the angle of the rearward and outward taper of the upper sidewall 25 of the second tapered portion 24, relative to the flat bottom face 22 is about 4 degrees. The angle of taper of the sidewalls 25 of the second tapered portion 24 is therefore shallower than the angle of taper of the front face 18, relative to the flat bottom surface 22. This creates the abrupt change in taper between the front face 18 and the second tapered portion which is mentioned above.

The second end 26 of the bullet is provided with a cut-out 27 and a fastener 28.

The fastener removably connects a chain 29 to the second end of the bullet. The chain is connected to an expander 30 which follows in the channel created by the bullet when it is dragged through soil. The expander 30 has a rounded leading edge 37.

Put another way, the bullet has an offset conical shape, but with a flat lower face and a pointed first end 17 having a front face 18 which tapers to an edge. The offset nature of the conical shape can be seen clearly in figure 7b. This shows the circular cross section defined by the sidewalls 24 at the second end 26, which is offset relative to the circular cross section adjacent to the front face defined by the sidewalls 19 at the pointed first end 17 of the bullet. The offset nature of the two circular cross sections still retains a plane of symmetry which is perpendicular to the flat lower face. This helps to stabilize the bullet and ensure that it follows a straight path.

Figures 6a-6c show plan, side and bottom views respectively of a bullet according to the invention. Similar features to those shown in the preceding figures are labelled using the same reference numerals. Any dimensions shown in these figures are non-limiting for the embodiments shown. They are only exemplary.

Figure 6a shows the top view of the bullet 15. The front face 18 and leading edge 23 are shown at the first pointed end 17 of the bullet. The rectangular recess 20 is shown. It is aligned along a longitudinal plane of symmetry A-A of the bullet.

The plane of symmetry A-A runs along the length of the bullet. The through holes 21 are shown in dotted lines. The flat bottom face 22 is shown in dotted lines. This feature is more clearly shown in figures 6b and 6c. The cut-out 27 is rectangular when viewed from above and sits on the plane of symmetry A-A of the bullet.

Figure 6b shows the front face 18 and the straight leading edge 23 at the first pointed end 17 of the bullet. The flat bottom surface 22 is also shown. The angle of taper 35 of the front face 18 is about 30 degrees. The angle of taper 36 of the sidewalls 25 of the second tapered portion is about 3 degrees. This is the same as the angle of taper of the sidewalls 19 of the first tapered portion.

Figure 6c shows the bottom view of the bullet. The recess 20 extends all the way through the bullet to form a recess 20 in the bottom face 22. A serial number 31 is optionally engraved on a recessed portion 32 of the bottom surface 22.

Figures 7a and 7b show perspective and end views respectively of a bullet according to the invention. Similar features to those shown in the preceding figures are labelled using the same reference numerals. Any dimensions shown in these figures are non-limiting for the embodiments shown.

In figure 7a, the recess 20 is shown extending all of the way through the bullet 15 in dotted lines, as are the cut-out 27 and the through holes 21 and 28.

In figure 7b, an end view of the bullet is shown, when viewed from the end which contains the cut-out 27. The elliptical front face 18 is shown in dotted lines since it is at the opposite end of the bullet. The sidewalls 19 meet the edges of the front face 18. These sidewalls 19 merge with the sidewalls 24 which are visible at their maximum width at the second end 26 of the bullet. The diameter of the bullet at its second end is 105 mm. In other embodiments the diameter of the bullet at its second end may be between 80 and 120 mm. The through holes 21 are shown in dotted lines. The end profile of the flat bottom surface 22 is also shown.

In use, the bullet is attached to the leg of a plough such as the one shown in figures 1-5. The plough is then dragged behind a vehicle such as a tractor with the bullet positioned at a desired depth below the soil surface. This provides a channel which is defined by the width of the bullet 15 (and the following expander 30). The channel runs parallel to the soil surface.

Statements of invention

1. A bullet for a mole drainer plough comprising; an elongate body having a first end and a second end, and an attachment member for attaching the bullet to a mole drainer plough, wherein the elongate body comprises; a first tapered portion adjacent the first end, and a second tapered portion between the first tapered portion and the second end.

2. A bullet according to statement 1 wherein the second tapered portion comprises a first cross section adjacent to the first tapered portion which tapers to a second cross section adjacent to the second end, wherein the second cross section has a larger area than the first cross section.

3. A bullet according to either preceding statement wherein an angle of taper of the second tapered portion is less than an angle of taper of the first tapered portion.

4. A bullet according to any preceding statement further comprising a flat bottom face.

5. A bullet according to statement 4 wherein the flat bottom face has a constant width over its entire length.

6. A bullet according to any preceding statement wherein the taper of the second tapered portion forms a continuous surface.

7. A bullet according to any preceding statement wherein the taper of the second tapered portion has a constant angle of taper.

8. A bullet according to any preceding statement wherein the second tapered portion extends over between 20% and 100% of the length of the elongate body.

9. A bullet according to any preceding statement wherein the first tapered portion comprises a front face.

10. A bullet according to statement 9 wherein the front face has a straight bottom edge which is connected to the rest of the periphery of the front face.

11. A bullet according to statement 10 wherein the rest of the periphery of the front face has an oval shape.

12. A bullet according to either of statements 10 or 11 wherein the straight bottom edge of the front face defines the boundary between the front face and a bottom surface of the bullet.

13. A bullet according to any of statements 9-12 wherein the front face has only one plane of symmetry.

14. A bullet according to any preceding statement wherein the bullet is formed of a high chromium steel.

15. A bullet according to any preceding statement wherein the attachment member comprises a slot for receiving a portion of a plough leg and two or more holes for receiving bolts to attach the bullet to the plough leg.

16. A mole drainer plough comprising a bullet according to any preceding statement.

17. A method of creating an underground channel comprising the steps; providing a mole drainer plough according to statement 16, and pulling the mole drainer plough behind a vehicle across a soil surface such that the bullet is located below the soil surface and creates the underground channel as the mole drainer plough is pulled across the soil surface.

Claims

Claims 1. A bullet for a mole drainer plough comprising; an elongate body having a first end and a second end, and an attachment member for attaching the bullet to a mole drainer plough, wherein the elongate body comprises; a first tapered portion adjacent the first end, and a second tapered portion between the first tapered portion and the second end.
2. A bullet according to claim 1 wherein the second tapered portion comprises a first cross section adjacent to the first tapered portion which tapers to a second cross section adjacent to the second end, wherein the second cross section has a larger area than the first cross section.
3. A bullet according to either preceding claim wherein an angle of taper of the second tapered portion is less than an angle of taper of the first tapered portion.
4. A bullet according to any preceding claim further comprising a flat bottom face.
5. A bullet according to claim 4 wherein the flat bottom face has a constant width over its entire length.
6. A bullet according to any preceding claim wherein the taper of the second tapered portion forms a continuous surface.
7. A bullet according to any preceding claim wherein the taper of the second tapered portion has a constant angle of taper.
8. A bullet according to any preceding claim wherein the second tapered portion extends over between 20% and 100% of the length of the elongate body.
9. A bullet according to any preceding claim wherein the first tapered portion comprises a front face.
10. A bullet according to claim 9 wherein the front face has a straight bottom edge which is connected to the rest of the periphery of the front face.
11. A bullet according to claim 10 wherein the rest of the periphery of the front face has an oval shape.
12. A bullet according to either of claims 10 or 11 wherein the straight bottom edge of the front face defines the boundary between the front face and a bottom surface of the bullet.
13. A bullet according to any of claims 9-12 wherein the front face has only one plane of symmetry.
14. A bullet according to any preceding claim wherein the bullet is formed of a high chromium steel.
15. A bullet according to any preceding claim wherein the attachment member comprises a slot for receiving a portion of a plough leg and two or more holes for receiving bolts to attach the bullet to the plough leg.
16. A mole drainer plough comprising a bullet according to any preceding claim.
17. A method of creating an underground channel comprising the steps; providing a mole drainer plough according to claim 16, and pulling the mole drainer plough behind a vehicle across a soil surface such that the bullet is located below the soil surface and creates the underground channel as the mole drainer plough is pulled across the soil surface.