GB2027771A - Deep Vertical Trench Plough - Google Patents

Abstract

The plough comprises a row of plough blades 2-5 one behind the other, each blade being shaped to lift soil as the plough is drawn. The blades are arranged at different depths so that succeeding blades extend progressively deeper into the soil. In this way the lower blades do not have to perform work on the soil above. The plough may be constructed for drain laying, mole draining or subsoiling operations, and may be drawn with considerably less draught than conventional deep ploughs, enabling it to be drawn behind conventional wheeled tractor vehicles. <IMAGE>

Description

SPECIFICATION Deep Vertical Trench Plough This invention relates to deep vertical trench ploughs and deep vertical trench ploughing attachments for tractor vehicles. By the term "deep vertical trench plough" there is meant in this Specification a plough that can cut in a single traverse a vertical or substantially vertical trench extending well into the subsoil. Such ploughs are used for drain laying, mole draining and subsoiling operations.

Deep ploughs currently in use, known as trenchless ploughs, merely cut into the soil, lift it and divide it laterally to an extent sufficient, for example, to lay a drain and allow the soil to fall back together after the plough has passed.

Considerable draught is required to draw the plough through the soil, and it is generally necessary to use a winch and cable traction system or a crawler, or tracked tractor unit.

Alternatively chain diggers can be used to excavate a trench so that a drain can be laid at the bottom of the trench before backfilling. Both these methods of deep ploughing are, however, extremely expensive in that they require powerful and expensive machinery that is costly to maintain.

This invention is based on the observation that the draught required to move a plough through the soil increases generally exponentially with the depth being ploughed.

This invention provides a deep plough having a row of plough blades one behind the other, each blade being shaped to lift soil as the plough is drawn, the blades being arranged at different depths, so that succeeding blades extend progressively deeper into the soil.

If the deep plough-of this invention is constructed so as to be useful for subsoiling operations, all that is necessary is for successive blades to lift the soil and allow it to fall back again as the plough passes. Preferably each blade holds the soil in its lifted condition while the succeeding blade lifts the soil beneath. The advantage of the multi-blade construction of the plough of this invention in such n application is that the lower blades, which have to deal with the less workable subsoiln to not have to perform work also on the soil bove. The plough is mor efficient and requires less draught than conventional deep ploughs cutting to a similar depth and width.

The plough may alternatively be for mole draining, in which case each blade preferably lifts and slightly divides the soil to allow free passage for a vertical knife drawn behind the row of blades and carrying at its lowest end a bullet extending to a depth lower than that of the deepest blade.

The bullet forms the mole plough's tunnel in the subsoil in the conventional manner, but the draught required to draw the plough is less than for conventional mole ploughing as the vertical knife does not have to cut through the soil for the whole of its depth.

A plough according to this invention is, however, most suitably used for the laying of land drains. The drains may be clay tile drains which are laid end to end in the subsoil with a regular fall, or a continuous porous or perforated pipe laid similarly. The drain laying apparatus may be mounted on or formed integrally with the plough, and the plough formed with blades which lift and divide the soil to an extent sufficient to allow the drain laying apparatus to extend to the bottom of the trench that is opened in the soil by passage of the plough. Advantageously the trench is kept open by side plates of the plough until the entire apparatus has passed, and is then allowed to fall back to fill the trench.

It is of particular advantage for the successive blades to be progressively narrower, so that the leading blade which cuts into the topsoil is broader and divides the soil further than the following blade, and so on until the deepest and narrowest blade which is the final one in the row.

In this way the construction can be such that the leading blade Jifts its soil to the surface and divides it so as to pile it equally on the surface on each side of the channel so formed in the soil; the next blade lifts its soil and divides it so as to deposit at the outer edges of the channel cut by the first blade; and any succeeding blades similarly lift their soil and divide it so as to deposit it at the outer edges of the channel above. By suitable design of blades it is thus possible to cut into the soil a vertical sided trench the sides of which are held by side plates of the plough while a drainage pipe is being laid and if desired backfilled. The sides of the trench can then be allowed to fall into the centre when the pipe laying apparatus has passed.The topsoil piled on the surface may be levelled by a final blade of the plough or by a separate pass with the tractor, as desired.

The deep plough of this invention enables wheeled tractors to be used for drain laying where previously crawler tracked tractors or winches were needed. It also enables larger drains to be laid when crawjer tracked tractors or winches are available.

The row of blades of the plough of this invention is preferably mounted on a rigid beam for towing behind a tractor. In this way adjustment of the angle of the beam to plough to a shallower depth causes the different blades to lessen the depth of penetration to different extents, so that the sharing of the work between the blades remains substantially constant. A preferred embodiment of this invention utilizes the trailing blade, which is also the deepest, to control the depth of the plough. The trailing blade is pivotally mounted on the beam, and its angle of presentation to the soil is variable by means of a hydraulic ram. Tilting of the blade to dig deeper into the soil pulls down the entire beam, until rotation of the beam provides once more the original angle of presentation of the trailing blade.

Conversely tilting of the trailing blade in the opposite sense causes the beam to rise until its rotation cancels the angle of tilt.

This invention is illustrated by the drawings of which: Figure 1 is a perspective view of a wheeled tractor pulling a plough according to this invention; Figure 2 is a side elevation of the plough, showing the rear part of the tractor; Figure 3 is a plan view from above of the plough, showing for simplicity only the plough blades, a pipe laying tube and a backfill hopper; Figure 4 is a front view of the row of plough blades; and Figure 5 is an illustrative diagram showing the soil movement over a section of a trench cut by the plough.

Figures 1 and 2 of the drawings show how the plough according to this invention is attached to be drawn behind a conventional wheeled tractor.

The plough comprises a rearwardly extending beam 1 made up of two side plates as can be seen in Figure 1. Beneath the beam 1 depend four plough blades 2, 3 4 and 5 of which the leading three are bolted between the opposite side plates of the beam 1 by means of bolts 6. The rearmost plough blade 5 depends similarly beneath the beam 1 but is pivotally mounted between the side plates by means of a pivot shaft 7. The plough blade 5 is provided with an integral upstanding web 8 through which the pivot shaft 7 passes and an upper end of which is pivotally connected to one end of a hydraulic ram 9 the other end of which reacts against the beam 1.

The four plough blades 2, 3, 4 and 5 extend into the soil in use to different extents, depending on the angle of inclination of the beam 1. The front plough blade 2 is the shallowest, and succeeding plough blades extend into the soil to progressively greater depths. In addition, the front plough blade 2 is the broadest blade, and the succeeding blades are progressively narrower so that the blade 5 is both the narrowest and the deepest.

As can be seen from Figures 3 and 4, the front plough blade 2 comprises a first blade portion 2a for lifting the soil, followed by a dividing portion 2b for dividing the soil and moving it outwardly to be deposited at each side of the trench so formed.

Similarly the plough blade 3 comprises a lifting portion 3a and a dividing portion 3b, the plough blade 4 comprises a lifting portion 4a and a dividing portion 4b and the plough blade 5 comprises a lifting portion 5a and a dividing portion Sb. However the lifting portion 5a of the last plough blade 5 has a base portion that slides over the bottom of the trench created by passage of the plough, so as to control the overall depth of cut in a manner to be explained below.

Referring to Figure 5, the operation of the plough of this invention is illustrated. As the plough is drawn through the soil, the leading blade 2 cuts a channel 2c into the soil. The earth from this channel is lifted by the blade 2a and divided by the blade 2b so as to be deposited in two mounds 2d one at each side of the channel.

The second blade 3, following immediately after the first, cut a further channel 3c into the soil. The soil from this channel 3c is lifted by the blade 3a and divided by the blade 3b so as to be deposited at the sides of the channel 2c. Similarly the succeeding blade 4 cuts a channel 4c and deposits the soil therefrom at the sides of the channel 3c, and the final blade 5 cuts a channel Sc and deposits the soil therefrom at the sides of the channel 4c. The deeper blades cut progressively narrower channels in the soil, so that the wear is well distributed between the blades 2 to 5. At the base of the deepest channel Sc the drainage pipe 10 is laid, using a conventional pipe laying attachment 11 towed directly behind the plough.The pipe laying attachment 11, shown in Figures 1 and 2, comprises a tube 1 2 for laying a continous flexible pipe 10, and a hopper 1 3 for back filling the channel Sc above the pipe 10 with aggregate.

Side plates 14 on each side of the pipe laying attachment cause the walls of the channel that has been opened to remain apart until after the plough and attachment have passed. Thereafter the walls fall together so as to close the trench, and the mounds 2d can be pushed back into position by a final blade of the plough (not shown) or by a separate pass with a tractor having a bulldozer attachment.

Depth control is monitored continuously, either automatically or by operator control, so as to ensure that the drainage pipe is laid at a generally constant fall. To achieve this, siting guides on the beam 1 and at two positions on the ground are kept in alignment. The depth of the plough is controlled by means of the hydraulic ram 9.

Extension of the ram 9 causes the upstanding web 8 of the rear plough blade 5 to rotate clockwise as viewed in Figure 2, with the effect that the flat base of the blade 5 rides up the bottom of the channel that has been cut, raising the plough blade 5 towards the surface of the soil.

This is accompanied by anticlockwise rotation of the beam 1, and when the rotation is sufficient the base of the plough blade 5 again assumes its original angle of inclination. Similarly, retraction of the ram 9 causes anticlockwise rotation of the upstanding web 8 of the rear blade 5, with the effect of increasing the depth of cut of the piough.

Because variation of the depth of cut of the rear blade 5 causes a change in the angle of inclination of the beam 1, all of the other plough blades cut two depths that are varied in proportion. Thus the overall work effected by the plough is shared between the various plough blades irrespective of the depth of cut.

Although the illustrated embodiment shows a plough according to this invention with four blades, it will be immediately apparent that this invention is applicable equally to deep ploughs having two or more blades.

Claims (9)

Claims

1. A deep plough having a row of plough blades one behind the other, each blade being shaped to lift soil as the plough is drawn, the blades being arranged at different depths so that succeeding blades extend progressively deeper into the soil.

2. A deep plough according to claim 1 for use in subsoiling operations, wherein each blade lifts the soil as the plough is drawn and holds it in its lifted condition while the succeeding blade or blades lift the soil beneath.

3. A deep plough according to claim 1 for use in mole draining, wherein each blade lifts and slightly divides the soil as the plough is drawn to allow free passage for a vertical knife drawn behind the row of blades and carrying at its lowest end a bullet extending to a depth lower than that of the deepest blade.

4. A deep plough according to claim 1 for laying land drains, wherein the blades lift the soil as the plough is drawn and divide it sufficiently to allow drain laying apparatus to extend to the bottom of the trench so opened.

5. A deep plough according to claim 4, wherein the successive blades are progressively narrower and are shaped so that the leading blade lifts the topsoil and divides it to pile it equally on the surface on each side of the channel so formed in the soil; the next blade lifts its soil and divides it tc deposit it at the outer edges of the channel above; and any succeeding blades similarly lift their soil and divide it to deposit it at the edges of the channel above.

6. A deep plough according to claim 5, wherein the blades are shaped to cut into the soil a vertical sided trench.

7. A deep plough according to claim 6, provided with side plates for supporting the sides of the trench while drain tiles or a drainage pipe is being laid.

8. A deep plough according to claim 5, 6 or 7, having a final blade shaped to level the surface and fill the trench when the pipe laying apparatus has passed.

9. A deep plough substantially as described herein with reference to the drawings.

9. A deep plough according to any preceding claim, wherein the blades are mounted on a rigid beam for towing behind a tractor vehicle.

10. A deep plough according to claim 9, wherein the deepest, trailing, blade is pivotally mounted on the beam with its angle of presentation to the soil variable under the control of a hydraulic ram.

11. A deep plough substantially as described herein with reference to the drawings.

New Claims or Amendments to Claims filed on 19 October 1 979.

Superseded Claims 1.

New or Amended Claims:

1. A deep plough having a row of plough blades one behind the other, each blade being shaped to lift soil as the plough is drawn and the blades being arranged at different depths so that different blades extend progressively deeper into the soil, wherein all but the deepest, trailing, blade are rigidly secured to a beam having at its forward end a towing hitch for mounting on a tractor vehicle, and the deepest trailing blade is pivotally mounted on the beam with its angle of presentation to the soil variable under the control of a hydraulic ram between the blade and the beam.