GB2238564A

GB2238564A - Pneumatic field clearing apparatus

Info

Publication number: GB2238564A
Application number: GB9025961A
Authority: GB
Inventors: Leslie James Shreeve
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-11-30
Filing date: 1990-11-29
Publication date: 1991-06-05
Also published as: GB8927119D0; GB9025961D0

Abstract

Apparatus for clearing fields comprises a frame adapted to be propelled over the field; suction means into which material is sucked as the apparatus progresses over the field; duct means through which collected material passes to discharge into a collecting bin; and a chain harrow (28) suspended from the frame so as to rake the surface of the field as the frame moves thereover, wherein the suction means is located to the rear of the chain harrow as viewed in the direction of travel, such that material loosened by the chain harrow is sucked into the suction means as the apparatus progresses over the field. <IMAGE>

Description

Title: Improvements in and relating to Field Clearing Apparatus ~ DESCRIPTION Field of invention This invention concerns field clearing apparatus particularly but not exclusively for clearing paddocks and fields of horse dung although the apparatus may be used for example for clearing straw used to protect crops against frost such as carrots, prior to harvesting.

Backqround to the invention Hitherto the task of removing dung from paddocks has been a manual one using a bucket and shovel or scoop.

Apparatus for clearing fields and yards of material such as leaves and dirt have typically utilised rotating brushes with or without scrapers, blades or rakes. Such apparatus has proved to be unsuited for clearing sticky material from grassland such as freshly dropped horse dung or dry matter in bulk such as straw from a field.

Other forms of apparatus for clearing leaves and other debris have comprised vaccum cleaners on transportable or powered carriages but experiment has proved that such machines are also quite unsuited for picking up sticky material such as freshly dropped horse dung and cannot readily handle bulk material such as straw particularly when the latter is wet.

It is an object of the present invention to provide apparatus for lifting such material from paddocks or fields (whether grassed or not) Summary of the invention According to the present invention apparatus for clearing fields comprises: a) a frame adapted to be propelled over the field; b) suction means into which material is sucked as the apparatus progresses o'rer the field and c) duct means through or which collected material passes to discharge into a collecting bin.

The apparatus preferably additionally comprises a chain harrow suspended from the frame so as to rake the surface of the field as the frame moves thereover. The suction means is then preferably located to the rear of the chain harrow as viewed in the direction of travel, such that material loosened by the chain harrow is sucked into the suction means as the apparatus progresses over the field.

The bin may be mounted on the frame or may be mounted on or form part of another vehicle which is towed behind the apparatus or is self propelled and driven behind or to the side of the apparatus.

The suction means may comprise a box having a slot in its underside through which material can be sucked and which includes a duct connection thereon for connecting to the said duct means.

A fan may be located in the box or in the duct means or in a housing associated theerewith, to provide suction.

According to a preferred feature of the invention the box is pivotally mounted relative to the frame and is suspended in such a manner that there is a tendency for the box to tilt so that the rearward edge of the slit in its underside rests on the ground surface when the apparatus is stationary, so that when the apparatus moves in a forward direction, the box will tilt in the opposite sense, lifting the rearward slit edge and causing the leading edge of the slit to tilt downwards.

According to a further preferred feature of the invention a strip of resiliently deformable material is secured to the box so as to extend across the leading edge of the slit (as viewed in the direction of forward travel of the apparatus), so as to constitute a flap which normally extends in a generally downward direction to engage the the ground, but with forward movement of the apparatus is forced rearwardly so as to define a resilient flap below which material is loosened by harrowing forced as the apparatus moves forward thereover. The action of the flap is twofold in that it closes the gap between the leading edge of the slit and the ground and secondly tends to squeeze the loosened material below the flap, causing it to spring upwardly as the flap passes thereover, so giving the material an upward component of motion into the suction intake.

The suction is advantageously created by an axial fan which'when rotated causes air to be displaced from its central axis in a radially outward direction, so as to cause a suction effect.

By mounting the fan in a cylindrical housing and by connecting the ducting from the collecting box to a central region of the housing, so loosened material below the box is thrown through the slot into the box and along the duct means towards the central region of the rotating fan from where it is radially accelerated by the fan into a further duct beyond the fan.

Preferably removable flaps are provided covering apertures in the wall of the duct means which when removed permit the ducting to be cleaned.

The duct beyond the fan may include a partition wall defining upper and lower compartments with an aperture in the partition wall which can be closed by a flap. Both compartments may be utilised by opening the aperture between the two compartments when the loosened material is relatively wet and sticky and therefore dense and heavy.

However, when the material is dry and lightweight, the flap may be shut so as to use only the lower duct, so that the material occupies only the lower half of the duct and leaves the duct in a manner which will enable it to be received in the collecting bin more reliably than might otherwise be the caste.

The apparatus may be self-propelled and provided with an engine and means for steering.

Alternatively the apparatus may be adapted- to be mounted on a tractor or other self-propelled vehicle either at the front, side or rear- thereof but particularly so that it extends laterally of the driving position of the vehicle so that the latter does not have to be driven over the material to be collected but, like a harvester, can be driven over the cleared land whilst the collecting box passes over the uncleared land.

Preferably the frame is in two parts, a mounting frame, adapted to be mounted on a three point linkage on the rear of a tractor and a lateral main frame below which the chain harrow and suction means are suspended, so that the latter can be raised and lowered (using the three point linkage lifting) to the required height.

The invention will be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of apparatus embodying the invention adapted for mounting to the rear of a tractor using the standard three point linkage on the latter, Figure 2 is a perspective view of the suction box and duct connection, Figure 3 is an end view in section of the collecting box showing the manner in which the box is suspended above the ground during collection.

Detailed description of drawings In Figure 1 a frame 10 is shown which is adapted for mounting to the three point linkage of a tractor and to this end incorporates lower mounting lugs 12 and 14 and an upper mounting bracket 16. A power take off (PTO) shaft 18 extends forwardly to engage the PTO of the tractor and to drive a gearbox 20 which in turn drives a radial fan (not shown) located within a fan casing 22 mounted on the frame 10.

Extending laterally from the frame 10 is a side member 24 on which is mounted a second frame 26 below the front end of which is carried the leading edge of a chain harrow generally designated 2R having a spreader bar 30 and below the rear of which is pivotally suspended a suction box generally designated 32 connected via flexible hose 34 and 36 and rigid duct sections such as 38 and 40 to the inlet of the fan casing 22.

Although not shown, the underside of the box 32 is closed except for a narrow slit which extends parallel to the length dimension of the box over the central region of the 9 length The outlet of the fan communicates with a rigid duct assembly 42 into which material which has been sucked up by the fan is blasted for delivery from the rear open end 44 of the duct assembly 42, to be discharged into a trailer or the like behind the tractor (not shown).

The duct assembly 42 includes removable side panels, end panels and top panels such as 46, 48 and 50 which upon removal nahie the interior of the ducting to be cleaned.

In addition the duct assembly 42 includes a dividing partition shown in dotted outline at 52 which completely extends between the upward frpnt wall of the duct assembly 42 to the open outlet 44 at the rear of the duct assembly.

The partition 52 includes an aperture normally covered by a sliding plate generally designated 54. The plate can be slid so as to open the aperture thereby enabling material and air from the fan to pass into both the upper and lower regions within the duct assembly 42. Closing the plate 54 however, restricts the passage through the duct to the lower half. Where material is particularly heavy due to it being wet, both parts of the duct can be used, but when the material is lightweight it is found to be more preferable to restrict the passage of the lightweight material to the lower part of the duct so as to prevent the latter from being projected too far rearwardly by the air stream and thereby possibly miss the collecting trailer.

Supports at 56 and 58 link the rear of the duct assembly 42 to the rear end of the frame 10. Likewise a support 60 links the bridge of the frame 10 to the front end of the duct assembly 42, to stabilise the latter relative to the frame 10.

The frame 26 is rigidly attached to the arm 24 but the suction box 32 is pivotally connected by means of an arm 62 which extends between the front wall of the box and a cylindrical sleeve 64 itself rotatable about an axle 66 carried in brackets 68,70,72 and 74 carried by the arm 24.

The sleeve 64 fits between the brakets 70 and 72 which thus axially locate the sleeve and therefore locate the box 32 (connected to the lower end of the arm 62) relative to the frame 26.

Also visible in Figure 1 is the rear spreader bar 76 for the chain harrow 28. The latter is joined to a support bar 78 carried by vertical legs 80 and 82 which themselves depend from and are attached to the arm 24. The spreader bar 76 is conveniently attached to the support bar by means of lengths of chain such as 84 and 86.

The box 32 includes two skids one of which is denoted by reference numeral 88.

As best seen in Figure 2, the box 32 is integrally formed at the lower end of a rectangular trapezoidal box 90 the upper end of which is formed with a cylindrical flange 92 to which the flexible hose 34 can be connected as by a jubilee clip (not shown). The box 32 and the box 90 are hollow and communicate so that material sucked into the box 32 can pass through the box 90 into the hose 34.

Referring to Figure 3, the front edge of the box 32 has attached theEeLO a neoprene rubber flap 94 which extends down and, when the machine is in forward movement, to the rear of the underside of the leading edge of the box 32 as shown in Figure 3. The flap thus forms a partial seal with the ground over which the box is moving and the suction effect of the fan is such as to cause air to enter the box below the trailing edge rather than from below the leading edge.

Horse dung such as 96 in advance of the box, passes below the rubber flap 94 and should then be caught up in the air StfaB entering the box from below the rear edge of the box so as to be drawn up through the boxes 32 and 90 into the ducting. It will be seen that, if any articles of dung or other material which is to be lifted by the machine fail to be drawn into the air stream as soon as they leave the rubber flap 94, the tendency will be for the incoming rush of air to accelerate the material in the same direction as that in which the box is moving so that the material is held captive to the rear of the rubber flap 94 and from where it is eventually sucked into the air stream and drawn into the ducting for discharge into the collecting bin or trailer behind the tractor.

The rubber flap 94 has thus been found to be an important feature of the invention in that whilst permitting the material to be collected to pass thereunder, the sealing effect of the flap with the ground causes the air stream entering the box to do so substantially from the rear of the box as previously described and it is this feature which ensures a reliable material gathering and collecting characteristic for the apparatus.

Attached to the front wall of the box 32 is the arm 62 but the cylindrical sleeve 64 is not shown attached to the upper end of the arm 62 for clarity.

The centre of gravity of the box 32 is such that the arms 62 and box attached thereto tend to rotate in an anticlockwise manner about the axle 66 and in order to prevent the box from moving too far forward, a stop 98 is secured as by welding to the sleeve 64. This engages the upper surface of the arm 24 and prevent excessive rotational movement of the box 32 about the axle 66, in an anticlockwise sense.

In one embodiment of the machine a five blade fan having a diameter of approximately 50 cms was driven at a speed of approximately 4500 rpm and this in combination with a slit opening on the underside of the box 32 having a length oE approximtely 100 cms and a width of approximately 12 cms gave the required suction to lift horse dung from grassland.

Claims

1. Apparatus for clearing a field, comprising: a) a frame adapted to be propelled over the field; b) suction means into which material is sucked as the apparatus progresses over the field; and c) duct means through which collected material passes to discharge into a collecting bin.

2. Apparatus according to Claim 1, additionally comprising a chain harrow suspended from the frame so as to rake the surface of the field as the frame moves thereover.

3. Apparatus according to Claim 2, wherein the suction means is located to the rear of the chain harrow as viewed in the direction of travel, such that material loosened by the chain harrow is sucked into the suction means as the apparatus progresses over the field.

4 Apparatus according to any one of the preceding claims: additionally comprising a collecting bin which is mounted on the frame.

5. Apparatus according to any one of the preceding claims, wherein the suction means comprises a box having a slot in its underside through which material can be sucked and which includes a duct connection thereon for connecting to the duct means.

6. Apparatus according to any one of the preceding claims, comprising a fan to provide suction.

7. Apparatus according to Claim 5 and Claim 6, wherein the fan is located in the box.

8. Apparatus according to Claim 6, wherein the fan is located in the duct means or in a housing associated therewith.

9. Apparatus according to Claim 5, wherein the box is pivotally mounted relative to the frame and is suspended in such a manner that there is a tendency for the box to tilt so that the rearward edge of the slot in its underside rests on the surface of the field when the apparatus is stationary, so that when the apparatus moves in a forward direction, the box will tilt in the opposite sense, lifting the rearward slot edge and causing the leading edge of the slot to tilt downwards.

10. Apparatus according to Claim 5 or Claim 9, wherein a strip of a resiliently deformable material is secured to the box so as to extend across the leading edge of the slot (as viewed in the direction of forward travel of the apparatus), so as to constitute a flap which normally extends in a generally downward direction to engage the surface of the field, but with forward movement of the apparatus is forced rearwardly so as to define a resilient flap below which material is loosened by harrowing forced as the apparatus moves forward over the surface of the field.

11. Apparatus according to any one of the preceding claims, wherein suction is advantageously created by means of an axial fan which when rotated causes air to be displaced from its central axis in a radially outward direction, so as to cause a suction effect.

12 Apparatus accords a to Claim 6 or Claim 11, wherein the fan is mounted in a cylindricl housing and wherein a collecting bin is connected by dusting to a central region of the housing, so that loosened material below the suction means is thrown along the duct means towards the central region of the rotating fan from where it is radially accelerated by the fan into a further duct beyond the fan.

13. Apparatus according to Claim 12, wherein the duct beyond the fan includes apartition wall defining upper and lower compartments with an aperture in the partition wall which can be closed by a flap.

14. Apparatus according to any one of the preceding claims, wherein removable flaps are provided covering apertures in the wall of the duct means, which flaps, when removed, permit the duct means to be cleaned.

15. Apparatus according to any one of the preceding claims, which is sol propelled and provided with an engine and means for steering the apparatus.

16. Apparatus according to any one of Claims 1-14, wherein the apparatus is adapted to be mounted on a tractor or other self-propelled vehicle so that it extends laterally of the driving position of the vehicle so that the vehicle does not have to be driven over material to be collected but can be driven over a cleared area of the field whilst the apparatus passes over an uncleared area of the field.

17. Apparatus according to Claim 16, wherein the frame is in two parts, the first part being a mounting frame adapted to be mounted on a three point linkage on the rear of a tractor, and the second part being a lateral main frame below which the suction means and any chain harrow are suspended, so that the suction means can be raised and lowered (using the three point linkage lifting) to a required height.

18. Apparatus according to any one of the preceding claims, substantially as herein described, with reference to and as illustrated in the accompanying drawings.