WO2000006835A1

WO2000006835A1 - Trenching apparatus

Info

Publication number: WO2000006835A1
Application number: PCT/NZ1999/000122
Authority: WO
Inventors: Stephen George Arthur Fenton
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-07-31
Filing date: 1999-07-29
Publication date: 2000-02-10
Anticipated expiration: 2001-01-31
Also published as: AU5452799A

Abstract

This invention relates to trenching apparatus (1) most commonly used for digging and maintaining drainage channels/trenches alongside roads, along fence lines and on a variety of properties. In one embodiment of the invention the trenching apparatus (1) includes a body (3) attachable to the power takeoff/hydraulic system (11) of a vehicle (7). The body (3) is capable of rotation about its radial axis. The body (3) includes a substantially open frame (4, 5) that supports multiple digging apparatus (6). The trenching apparatus (1) is characterised in that during rotation of the body (3) the digging apparatus (6) transfers either or both materials and liquids into the body (3) from the trench being excavated or maintained. The materials/liquids are then discharged from the rotating body (3) in a substantially uniform manner onto adjacent surfaces.

Description

TRENCHING APPARATUS

TECHNICAL FIELD

This invention relates to trenching apparatus.

In particular, it is envisaged the trenching apparatus will be most commonly used for digging drainage channels or trenches or cleaning out such trenches or channels, along the side of roads, on rural sites, and on other properties.

Typically, the trenching apparatus will be most commonly used to create such trenches and channels in most soils, but in particular peat. However, the trenching apparatus may also be used to create drainage channels and so forth in range of soil types including clay.

In addition, the present invention could have application outside this field.

BACKGROUND ART

A range of equipment is currently available for use in trenching operations.

Typically, such equipment operates in conjunction with, and is attached to the power take-off drive or hydraulic apparatus of another vehicle - such as a tractor, or an excavator.

Available trenching equipment may include a combination of blades, scoops or discs which may be either fixed or pivotally mounted to a frame to enable the equipment to scrape, dig, and scoop out earth and so forth to create a trench of a particular depth and width.

However, there are a number of problems with existing systems.

Systems that use a cutter and plough arrangement operate to loosen the soil in a trench, partially excavate the trench and then compress the remaining material within the trench. However, this system can result in the walls of the trench comprising loose material which can be dislodged and fall into the trench resulting in the trench becoming partially blocked by this material at a later stage.

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SUBSTITUE SHEET Rule 26 Other types of trenching equipment may incorporate a scoop to scoop out loosened or poorly compacted material from the trench. However, the scoops typically tip the material along side the edges of the trench where it can then be washed back into the trench in unfavourable weather conditions. The material collected in the scoop may also be emptied into a trailer of a vehicle for dumping elsewhere. The removal and dumping of unwanted material increases both the cost and the labour involved in trenching operations. Alternately, the collected material may be spread over pastures or adjacent land. Such spreading can be uneven and can result in pasture damage.

Generally the types of trenching apparatus/excavator as described above are also often slow and correspondingly the trenching operation can be costly.

In addition, such trenching apparatus/excavators as described above are not typically designed to accommodate the problems encountered when creating water channels in peat. Peat by its nature can create a range of problems for existing trenching systems. Peat soils can be spongy, have a greater water content than other soil types and can become easily compressed.

Another type of trenching/excavating system is therefore commonly used for excavating peat soils. These are known as drain spinners. Typically drain spinners include a circular disc with a number of blades arranged around the perimeter of the disc (as described in New Zealand Patent Application No. 192469). As the disc rotates, the blades dig into and lift the peat out of the trenches being created. Unfortunately, similar problems arise with the use of this system as previously described systems, insofar as excavated material is again discharged unevenly on adjacent pasture or ground with detrimental consequences for pasture growth, and problems consequent on erosion and so forth.

Yet other systems include rotating drums which include blades or paddles for removing loosened material from a trench to create a drainage channel and so forth. Again this system operates by the blades lifting loosened material from the trench. The material is again unevenly disbursed on adjacent pasture or piled up for later dispersal along side the trenches.

SUBSTITUE SHEET Rule 26 It would be an advantage to have a trenching apparatus which would overcome the above mentioned problems. For example, to have an trenching apparatus which would:

a) be able to operate effectively on peat as well as other soil types; and

b) be able to excavate trenches quickly therefore being of cost benefit to land owners or public authorities requiring trenches and/or drainage channels to be dug; and

c) spread material excavated from the drainage channels evenly over adjacent ground without the negative consequences of pasture damage or uneven spreading, nor the cost involved with having to arrange a separate spreading operation; and

d) be able to not only dig and clear trenches of soil, peat or wood debris material, but also be capable of lifting and removing a certain amount of water from the trenches being dug; and

e) be cheap to produce; and

f) be able to be easily modified to tailor the trenching apparatus for a variety of trenches from wide drainage channels to channels required for laying field tiles and so forth; and

g) be able to be easily attached to existing excavators, tractors and so forth as required, but which can operate to dig a trench, water channel and so forth along either side of the vehicle to which it is attached, if required.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided a trenching

SUBSTITUE SHEET Rule 26 apparatus capable of preparing and maintaining at least one surface, including a body, the body including framing capable of supporting multiple digging apparatus.

Trenching apparatus substantially as described above wherein the framing of the body is configured to form a substantially open frame work.

Trenching apparatus substantially as described above wherein the framing is configured to complement the required shape of a trench being prepared and maintained.

Trenching apparatus substantially as described above wherein the framing is configured to be substantially cone-shaped.

Trenching apparatus substantially as described above wherein the digging apparata on the framing are configured in a substantially spiral arrangement around the body.

Trenching apparatus substantially as described above wherein the digging apparata can be configured to project at an angle from the framing.

A trenching apparatus substantially as described above wherein the body of the trenching apparatus rotates to enable the digging apparatus to prepare and maintain the trench being excavated.

A trenching apparatus as substantially described above wherein material from the surface being excavated collects within the body and is dispersed through the open frame work of the body as a result of forces created by rotation of the trenching apparatus.

Trenching apparatus substantially as described above wherein the trenching apparatus is laterally disposed relative to a vehicle with which the trenching apparatus is used.

A method of preparing and maintaining at least one surface using the trenching apparatus substantially as described above, including the steps of:

SUBSTITUE SHEET Rule 26 a) attaching the body of the trenching apparatus to a vehicle capable of activating the trenching apparatus; and

b) activating the trenching apparatus such that the digging apparatus digs into at least one surface;

and characterised by material from the surface being collected within the body of the trenching apparatus and then dispersed through the framing of the body onto a surface adjacent to the surface being excavated.

For the purpose of this specification the word "trench" shall mean any trench, channel or ditch excavated for whatever purpose including preparation and maintenance of a water course for drainage, or as a boundary trench and so forth. Accordingly, use of this term is not to be seen as limiting.

For ease of reference, the trenching apparatus shall now be referred to as a drain spinner. This term is used in the prior art to describe trenching systems that incorporate flat discs with digging blades bolted around the perimeter of the disc, and where such discs rotate. However, in the present specification the term drain spinner is used simply because the trenching apparatus rotates when it is activated and this rotation or spinning is required to enable the trenching apparatus to excavate a trench or drain. Therefore, use of this term is not to be seen as limiting the invention.

Also for ease of reference, the digging apparata shall now be referred to as blades. It should be appreciated that the term blades includes any form of blade, paddle, teeth and so forth of any shape or configuration as required to perform the function of the digging apparata of the present invention.

In preferred embodiments of the present invention the framing of the body of the drain spinner includes multiple bars that are fixedly attached along their length to the perimeter of a number of rings. The rings serve as structural strengthening and/or shaping framework for the attached bars.

As a result of the arrangement of the bars and rings, the framing results in the body having a substantially open frame work. However, the length and number of bars

SUBSTITUE SHEET Rule 26 and the diameter of the rings comprising the framing may vary depending upon the configuration required to enable the drain spinner to excavate trenches for specific purposes. For example, the framing of the body of the drain spinner required to excavate a trench for field tiles may be differently configured to the framing of the body used to create an open drainage channel. Accordingly, the open framework of the drain spinner may be achieved by an appropriately cut and moulded external surface of sheet metal, attached to an internal framework of any combination of rings and/or structural stays.

For example, in one embodiment used to create an open drainage channel there is nine primary bars that extend the entire length of the body, and nine secondary bars which extend for a portion of the length of the body. In this arrangement, the primary and secondary bars are configured in an alternating arrangement.

In the same embodiment, the diameter of the rings vary such that the narrowest diameter rings are positioned towards the point of attachment of the body to a vehicle, and the wider diameter rings preferably being located furthest from the point of attachment of the drain spinner to the vehicle. Accordingly, when the bars are attached to the rings, the body is configured to be substantially cone-shaped for most of its length with the bars radiating upwards and outwards from the point of attachment of the body of the vehicle.

In addition, in some embodiments, the bars of the framing may be configured to include an angled portion. For example, in one preferred embodiment, the diameter of the outermost ring is less than that of the next adjacent inner ring such that the bars when attached to the outermost ring are substantially angled inwards. In such embodiments, this portion of the body converging in towards the centre of the body contributes to defining a trench having the required depth, width and overall configuration to suit the particular purpose for which it is excavated.

The overall configuration of the described embodiment is therefore substantially diamond-shaped

In preferred embodiments of the present invention the width of the bar(s) to the diameter of the rings is designed to facilitate the discharge of surface material,

SUBSTITUE SHEET Rule 26 debris and water from the trench being excavated. For example, the measurements relevant to one embodiment of the cone-shaped/diamond-shaped body, include a bar width of approximately 80mm (millimeters) wide, whilst the diameter of the rings from the outer ring to the inner ring are 1.3m (metres), 1.5m, 1.14m, 0.78m and 0.4m respectively. However, the width of the bar to the ring diameter in other embodiments may vary depending upon the width, and depth of the trench, and the specific purpose for which the trench is being excavated. Accordingly, the body may be otherwise configured to be more rounded, or drum-shaped and so forth as required.

To facilitate excavation of the trench, each bar of the framing includes a number of digging apparata or blades. In preferred embodiments of the present invention the blades on a bar (whether on a primary bar or a secondary bar) are offset relative to the position of the blades on adjacent bars. Accordingly, the blades are arranged in a substantially spiral configuration around the body. This arrangement facilitates a more uniform excavation of the trench, whilst at the same time minimising the need for large scoops or paddles as is often provided with the prior art systems. In one preferred embodiment, each blade provides a 10mm cut, although cuts of up to 25mm may be achieved depending on the blade size, shape, position and projection from the frame. Small blades are preferable where there is a likelihood of encountering wood or debris material in the ground being excavated. The smaller blades are more efficient in breaking apart the debris, to facilitate its excavation with minimum damage to the blades.

In the cone-shaped embodiment previously described the blades are distributed along the entire length of the bars. The shape of the body and the positioning of the blades contribute to creating a trench that has a substantially flat bottom and at least one angled side-wall. As can be seen the shape of the trench can be dictated by the body shape and blade position, in order to create a trench for a specific purpose.

To increase the durability of the drain spinner, the blades are preferably fixedly attached to the bars of the framing. Accordingly, the blades may be welded onto the bars, or the bars and blades may be profile cut as required. This provides an

SUBSTITUE SHEET Rule 26 advantage over prior art systems where the blades, paddles or scoops are usually attached to the body of the trenching apparatus via bolts or similar attachment means. However, in some embodiments of the present invention where it is preferable to have replaceable blades, the blades may be removably attached to the framing by appropriate attachment apparatus.

To further improve the operation of the blades, the blades extend or project at an angle from the surface of the bars. Having the blades projecting out from the bars enables the blades to dig into surface and scoop out the material being excavated from the trench.

However, the configuration of the drain spinner is such that material dug by the blades is scooped into the centre of the body.

During activation of the drain spinner, the body rotates. Accordingly, whilst the blades are configured to dig into the surface and carry material into the centre of the body of the drain spinner, the rotational movement of the drain spinner creates a centrifugal force that discharges the material within the body out through the open frame work of the drain spinner. The material being excavated is therefore discharged from within the drain spinner and onto the surface of the ground adjacent to the trench being excavated. The rotation of the body, the scooping action of the blades and the speed with which the drain spinner operates contribute to the production of what can be termed a "rooster tail" (a term commonly used in water sports) of both solid and liquids from the trench being excavated. Accordingly, even water can be picked up and lifted out of the trench. This is advantageous when digging trenches in peat soils which are water laden and where the presence of water could impede the ability of prior art systems to effectively and efficiently excavate the trench.

The rate of discharge and the pattern of discharge of both the solid materials and liquid is such that there is an even spread of the discharged solids and liquids onto a ground adjacent to the trench being excavated. Therefore, the present invention obviates the need to further spread the excavated material. In addition, the pattern of discharge is such that a light coating of discharge material settles on adjacent ground. Accordingly, the discharged material is less likely to result in the type of

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SUBSTITUE SHEET Rule 26 pasture damage that can occur with use of prior art systems where discharged material is spread unevenly on adjacent pasture.

In some embodiments, the invention may also incorporate an additional system to catch the discharged solid material to further control its displacement. For example, use of an automat (a wide belt capable of catching the discharged material and then spreading it) may be used. This may be particularly appropriate to prevent sodden materials from being discharged over farm races, drives or adjacent roads or buildings.

An advantage of the present invention arising from the configuration of the body is that the body is capable of excavating a trench deeper than the radius of the body. Some prior art systems are only able to excavate a trench of a depth equal to the radius of the apparatus, such as with drain spinners which comprise a flat disc with blades fixed around the perimeter of the disc.

Accordingly, because of the depth to which the present invention can excavate, and the configuration of the body, along with the speed with which excavated material is discharged from the trench, operational resistance encountered using the present invention is less. Therefore, the speed with which the trench is excavated is correspondingly increased.

In prior art systems where only 50% of the surface of the trenching apparatus is contributing to the excavation at any one point in time, such systems encounter more drag and resistance, the excavating apparatus is also on the ground for longer periods. Therefore, compared with the present invention the extent of excavation achieved can be substantially reduced.

The configuration of the present invention is ideally suited for excavating trenches in peat. There are inherent problems when excavating peat as it is soft and not abrasive. The configuration of the body of the present invention has proven to be successful in the excavation of trenches in such material. However, the present invention may also be used to excavate trenches in other soil types, including clays.

In addition, the configuration of the body (particularly the blades on the bars of the framing), contributes to the ease of operation of the drain spinner. For example,

SUBSTITUE SHEET Rule 26 when the drain spinner is activated to rotate and is lowered onto the ground surface, the rotation in conjunction with the digging action of the blades, contributes to driving the drain spinner down. This is different from some systems where there is often a huge power requirement to overcome the drag that the digging apparata of such system encounters during operation.

In preferred embodiments of the present invention the drain spinner is adapted to attach to the three-point linkage of a vehicle such as a tractor or excavator. Such vehicles are well suited to the variety of terrains and ground conditions where trenches and water channels may be required.

Preferably, the drain spinner is pulled behind a tractor. However, in other embodiments, the drain spinner may operate in front of the tractor or to the side.

It is preferable for the drain spinner to be pulled ridged mounted behind a tractor because of the undertow created by the rotation of the drain spinner and the way the blades dig into the ground. To some extent this undertow is compensated by including a ground wheel or skid that contributes to the stabilisation of the drain spinner during its operation. This is optional. The ground wheel also contributes to the stabilisation of the tractor pulling the drain spinner. This stabilisation is particularly important as the body of the drain spinner is preferably laterally disposed relative to the vehicle with which the drain spinner is used.

Whilst the ground wheel is preferably positioned in front of the body of the drain spinner, in other embodiments the ground wheel may be positioned to follow the body of the drain spinner.

The ground wheel may take any configuration as is required to complement the operation of the drain spinner. In addition, any other suitable stabilisation apparatus may be adapted for use with the invention.

For example, to further improve the stabilisation of the drain spinner during its operation, and/or the vehicle with which it is used, counterweights may be employed as necessary and where required. For example, counterweights may be positioned on or about the vehicle or along the arm which is attached to the three- point linkage of the vehicle and which connects the drain spinner to the vehicle.

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SUBSTITUE SHEET Rule 26 The arm that attaches the drain spinner to the vehicle and facilitates the operation of the drain spinner can take any suitable configuration. For example, a modified truck axle may be used. Preferably however, the arm to which the drain spinner is attached is capable of pivoting and hinging to enable a portion of the arm to which the drain spinner is attached to be raised or lowered relative to the surface of the ground that is to be excavated. Accordingly, the drain spinner can be lowered to the ground surface and then activated in order to excavate the trench as required. When the trenching operation is completed, the drain spinner can be raised so as to be in a substantially vertical position (substantially perpendicular to the level of the ground) to enable the drain spinner to be transported to another location.

In addition, the arrangement of the arm is such that the drain spinner can be raised up and the arm can then be swung over the tractor (or swung laterally behind the tractor) to enable the drain spinner to be positioned on the opposite side of the tractor.

Accordingly, the drain spinner can be used to excavate trenches on either side of the tractor as required.

This configuration of the attachment of the drain spinner to the vehicle has advantages over some prior systems that may be centrally mounted on a tractor and dragged behind the tractor. Such systems are therefore unable to excavate trenches directly adjacent to a fence line. Yet other systems may only operate to raise the prior art systems up sufficiently only to clear the ground for transport. Or alternately, require time and labour intensive adjustments to reposition the trenching apparatus from one side of the vehicle to operate from the other side of the vehicle.

In general, when the trenching apparatus is laterally disposed from one side of the vehicle, the body of the drain spinner is capable of rotating in one direction. Accordingly, when the drain spinner is laterally displaced relative to the opposite side of the vehicle the body rotates in a counter direction.

Preferably, the drain spinner will be activated by the hydraulic system of the vehicle with which it is used. However, any system for driving the drain spinner

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SUBSTITUE SHEET Rule 26 may be employed as required.

In preferred embodiments of the present invention the body of the drain spinner is preferably made from high abrasion steel. High abrasion steel is preferred because of the wear and tear that the bars and the blades will be exposed to when excavating abrasive material in the surface being excavated. Whilst peat is not as abrasive as some soils, the speed with which the drain spinner operates and the existence of debris within the peat can contribute to the speed with which the bars and the blades will be abraded. However, where cost is an important factor, cheaper versions may be constructed from mild steel.

While steel is the preferred material used in the construction of the drain spinner, any suitable material that enables the drain spinner to function effectively may be used.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 Is a diagrammatic perspective view of the trenching apparatus and its accompanying ground wheel in a position ready to excavate a surface, and illustrated in conjunction with a vehicle with the trenching apparatus is used, in accordance with one embodiment of the present invention, and

Figure 2 Is a diagrammatic perspective view of the trenching apparatus attached to an arm which in turn is attached to the vehicle with which the trenching apparatus is used, in accordance with one embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

With reference to the diagrams by way of example and there is provided a trenching apparatus generally indicated by arrow (1), capable of preparing and

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SUBSTITUE SHEET Rule 26 maintaining at least one surface generally indicated by arrow (2).

The trenching apparatus 1 includes a body generally indicated by arrow (3). The body includes framing (4) and (5). The framing (4) and (5) is capable of supporting multiple digging apparata (or blades)(6). The trenching apparatus (or drain spinner) (1) is typically pulled behind and driven by a vehicle (7).

As shown in Figures 1 and 2 the drain spinner (1) is laterally disposed relative to the vehicle (in this case a tractor) (7) with which the drain spinner (1) is used.

The drain spinner (1) is attached to an arm (8) that in turn is attached to the three- point linkage (not fully shown) of the vehicle (7). The arm (8) is capable of pivoting at (9) to enable the drain spinner (1) to be operated between a position for transportation as shown in Figure 2, and a position for excavating as shown in Figure 1.

The drain spinner (1) may be laterally disposed relative to either side of the vehicle (7) with which the drain spinner (1) is used. In order to change sides of the vehicle, the arm (8) is raised and pivoted at (9) to enable the drain spinner (1) to also be raised and carried over the length of the tractor from one side of the tractor (7) to the other. In other embodiments the position of the drain spinner (1) on either side of the tractor (7) may simply be achieved by moving the drain spinner (1) through a horizontal plane behind the tractor (7). Accordingly, drain spinner (1) can be used to create a trench (10) on either side of the vehicle with which the drain spinner (1) is used, if required.

The drain spinner (1) is preferably driven via power from the three-point linkage of the tractor (7) in conjunction with the hydraulic systems (11) of the tractor (7). However, any suitable means of powering and operating the drain spinner (1) may be employed.

The very operation of the drain spinner (1) creates an undertow at the front of the drain spinner (1). Therefore, to stabilise the operation of the drain spinner (1), a ground wheel (12) may be employed. Preferably, the ground wheel (12) leads the drain spinner (1) as shown in Figure 1. However, in other embodiments, the ground wheel (12) may trail the drain spinner (1).

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SUBSTITUE SHEET Rule 26 In some embodiments, additional stabilising equipment such as counter-weights (not shown) may be employed to further stabilise the vehicle (7) and/or the drain spinner (1) during the trenching operation as required.

In one embodiment, as shown in the attached figures, the body (3) of the drain spinner (1) includes framing comprised of bars (4) and rings (5) arranged in a substantially cone-shaped configuration. The bars (4) radiate upwards and outwards from the base of the drain spinner (1) and are maintained in position by their attachment to the rings (5).

In the embodiment shown in Figures 1 and 2 there are nine primary bars (14), nine secondary bars (15) and five rings (6). However, the number and arrangement of bars (4) (either or both primary or secondary) and rings may vary between embodiments. The overall configuration of the body (3) is dictated by the width and depth of the trench (10) and the purpose for which it is being excavated.

In the substantially cone-shaped embodiment of the drain spinner (1) illustrated in Figures 1 and 2, the bar width is approximately 80mm (millimeters). The diameter of the rings (5) attached to the bars (4) on the interior surface of the cone have varying diameters as required to create the desired shape. For example, the diameter of the rings (5) from the outer ring furthest from the arm (8) are approximately 1.3m (metres), 1.5m, 1.14m, 0.78m and 0.4m.

The width of the bars (4) to the diameter of the rings (5) is important to create a sufficiently strong yet open frame work required to enable the drain spinner (1) to discharge excavated material effectively and efficiently.

However, the diameter of the rings (5) of other embodiments may accordingly vary depending on the required shape to effect a trench of the required depth, width and shape and to facilitate discharge of excavated material.

Also in the embodiment shown in Figures 1 and 2, a portion of the bars (5) are angled inward at (13) to form an overall diamond-shaped body. However, in other embodiments the overall shape of the drain spinner (1) may be configured as required to excavate trenches to the required width, depth and for a specific purpose. Accordingly, the drain spinner may be more circular in configuration or

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SUBSTITUE SHEET (Rule 26 may be substantially drum-shaped.

The bars (4) of the framing include the digging apparata or blades (6).

Preferably, the blades (6) on one bar are disposed relative to the blades (6) on adjacent bars such that the blades (6) are arranged in a substantially spiral configuration around the body (3).

In addition, the blades also preferably project from the surface of the bars (4) substantially at an angle. The angular projection of the blades (6) from the bars (4) enable the blades (6) to dig into and excavate material from the surface (2) on which the drain spinner (1) is being used.

As can be seen from Figures 1 and 2 framing of the body (3) forms a substantially open framework. The open framework contributes to the operation of the drain spinner (1). During operation, the body (3) rotates in a preferred direction. The body (3) is lowered to the surface (2) to be excavated. The blades (6) dig into and excavate the surface (2) and in so doing, carry the surface material to the inside of the body (3). The rotation of the body (3) and the speed with which it operates, creates a substantially centrifugal force which in turn causes the material transferred to the inside of the body (3) to be discharged through the substantially open frame work of the body (3). In effect, the discharged material is thrown up and out in a manner equating to a "rooster tail" typically associated with the water jet produced by racing boats travelling at speed. The rate and pattern of discharge of the material is substantially even. Accordingly, the material excavated from the trench (10) is discharged over ground adjacent to the trench in an even spread. Thereby problems encountered with prior art systems that result in an uneven displacement of excavated material which can require additional spreading (at a cost) or which can contribute to pasture damage may be obviated.

The particular configuration of the drain spinner (1) as shown in Figures 1 and 2 enable the drain spinner (1) to be used to excavate trenches (10) in peat. However, the drain spinner (1) as shown in Figures 1 and 2, or as in other embodiments (not shown) can be used in other soil types including clay.

The blades (6) of the drain spinner (1) are of a size and configuration which

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SUBSTITUE SHEET Rule 26 enables the blades to break apart wooden debris material typically found in peat, without undue damage caused to the blades (6).

To further strengthen the drain spinner (1), the bars (4) and the blades (6) are preferably fixedly attached to each other. This may be achieved by welding the blades 6 to the bars (4). However, to maintain strength of the shape of the body (3), the bars (4) and blades (6) are preferably profile cut.

Preferably high abrasion steel is used in the manufacturer of the drain spinner (1). However, where low cost systems are required, mild steel may be used. Where mild steel is used, it must be remembered that surface material will ultimately wear the bars (4) and the teeth (6). However, the ease of manufacture and the low cost of materials enables replacement drain spinners (1) to be manufactured relatively cheaply.

Where the discharge of material from the trench (10) being excavated requires further control, the present invention may also include an additional system for catching the material and controlling its displacement. Such a system may include an automat (such as a wide belt) (not shown) for use with the drain spinner (1).

One of the features of the present invention is that the drain spinner (1) is not only capable of drain excavation and clearing existing trenches (10) of built up debris, but also the body (3) is capable of picking up and lifting water out of the trenches (10) being excavated.

A further advantage of the present invention is the speed with which the drain spinner (1) can operate. The configuration of the body (3) is such that drag or resistance during excavation of a trench (10) is much less than that encountered with the use of prior art systems. This is because some prior art systems cannot operate deeper than the radius of the excavating drum or discs. Accordingly, such systems encounter more drag and resistance and have a high power requirement. In addition, many prior art systems are centrally mounted behind a vehicle. Accordingly such systems are unable to excavate trenches close to a fence line.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto

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SUBSTITUE SHEET Rule 26 without departing from the scope thereof as defined in the appended claims.

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SUBSTITUE SHEET Rule 26

Claims

THE CLAIMS DEFINING THE INVENTION ARE:

1. Trenching apparatus for either or both excavating and maintaining trenches in a surface, the trenching apparatus including a body capable of being attached to a vehicle,

the body being capable of rotation about its radial axis, the body including

a substantially open frame, and

the frame including multiple digging apparata,

the trenching apparatus characterised during rotation of the body by the digging apparata transferring either or both materials and liquids into the body from the trench being excavated or maintained.

2. Trenching apparatus as claimed in claim 1 wherein the frame of the body is configured to include multiple bars fixedly attached along their length to the perimeter of at least two rings.

3. Trenching apparatus as claimed in claim 2 wherein the bars of the frame attached to the rings are configured to complement the required shape of the trench being excavated or maintained.

4. Trenching apparatus as claimed in claim 3 wherein the bars of the frame are arranged as primary bars extending the entire length of the body and secondary bars extending for a portion of the length of the body.

5. Trenching apparatus as claimed in claim 4 wherein the primary and secondary bars are configured in an alternating arrangement.

6. Trenching apparatus as claimed in claim 5 wherein each bar of the frame includes digging apparata.

7. Trenching apparatus as claimed in claim 6 wherein each digging apparatus on a bar is offset relative to the positions of digging apparata on adjacent bars.

SUBSTITUE SHEET Rule 26

8. Trenching apparatus as claimed in claim 7 wherein the digging apparata on the bars are arranged in a substantially spiral configuration around the body.

9. Trenching apparatus as claimed in claim 8 wherein the digging apparata extend at an angle from the bars.

10. Trenching apparatus as claimed in claim 9 wherein the digging apparata extending at an angle from the bars enable the digging apparata to effect a cut in the trench surface and scoop out materials and liquids from the trench during operation of the trenching apparatus.

1 1. Trenching apparatus as claimed in claim 10 wherein the effected cut in the trench surface is further determined by the dimensions of each digging apparatus.

12. Trenching apparatus as claimed in claim 11 wherein the dimensions of each digging apparatus effects a cut in the trench surface of up to 25mm.

13. Trenching apparatus as claimed in claim 12 wherein the dimensions of the digging apparata in conjunction with the arrangement of the digging apparata on the frame and the configuration of the frame enable more than 50% of the body of the trenching apparatus to contribute to excavation or maintenance of the trench at any time.

14. Trenching apparatus as claimed in claim 13 wherein the dimensions of the digging apparatus and the cut size effected facilitates excavation of materials and liquids from trenches in a range of soil types, including peats, clays and sandy loams.

15. Trenching apparatus as claimed in claim 14 wherein materials and liquids excavated by the digging apparata from the trench are scooped into the centre of the body.

16. Trenching apparatus as claimed in claim 15 wherein materials and liquids scooped into the centre of the body by the digging apparata are discharged from the body and the trench through the substantially open frame via

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SUBSTITUE SHEET Rule 26 rotation of the body about its radial axis during operation of the trenching apparatus.

17. Trenching apparatus as claimed in claim 16 wherein rotation of the body creates a centrifugal force effecting discharge of materials and liquids from the body and the trench.

18. Trenching apparatus as claimed in claims 15 through 17 wherein the centrifugal force created by rotation of the body, in combination with the scooping of materials and liquids into the centre of the body by the digging apparata, contribute to a substantially continuous rate and pattern of discharged materials and/or liquids as a "rooster tail", through the frame and on to surfaces adjacent to the trench.

19. Trenching apparatus as claimed in claim 18 wherein the rate and pattern of discharge of materials and liquids on to surfaces adjacent to the trench obviates the need to further control the spread the excavated material.

20. Trenching apparatus as claimed in claim 19 wherein the spreading of discharged materials and liquids is optionally further controlled using additional collection apparatus.

21. Trenching apparatus as claimed in claim 18 wherein the rate and pattern of discharge of materials and liquids through the frame is facilitated by the substantially open configuration of the frame.

22. Trenching apparatus as claimed in claim 21 wherein the open configuration of the frame is determined in part by the ratio of the width of the bars to the diameter of the rings.

23. Trenching apparatus as claimed in claim 22 wherein configuration of the frame effects excavation or maintenance of a trench deeper than the radius of the body.

24. Trenching apparatus as claimed in claim 23 wherein any combination of rotation of the body, configuration of the frame, depth of excavation, and

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SUBSTITUE SHEET Rule 26 speed of discharged materials and liquids from the trench, co-operate to reduce operational resistance encountered by the body and correspondingly increase the speed with which the trench is excavated.

25. Trenching apparatus as claimed in claim 24 wherein the speed with which the trench is excavated is further facilitated by the digging apparata contributing to maintaining the body in contact with the contour of the trench surface, thereby countering mechanical constraints or resistance arising from the configuration of the body or insufficient power source supplied by a vehicle to which the body is attached.

26. Trenching apparatus as claimed in claim 25 wherein the body is attached to the vehicle via an arm.

27. Trenching apparatus as claimed in claim 26 wherein the arm is adapted to attach to either or both the three-point linkage and hydraulic system of the vehicle.

28. Trenching apparatus as claimed in claim 27 wherein the arm is pivotable to enable the body to be positioned relative to either or both the vehicle and the trench surface being excavated or maintained.

29. Trenching apparatus as claimed in claim 28 wherein the position of the body of the trenching apparatus when in use is laterally disposed relative to the vehicle to which the body is attached.

30. Trenching apparatus as claimed in claim 29 wherein lateral disposition of the body relative to the vehicle facilitates excavation or maintenance of trenches directly adjacent to a fence line.

31. Trenching apparatus as claimed in claim 30 wherein the position of the body when not in use is substantially perpendicular relative to the vehicle and the trench surface to facilitate transportation of the trenching apparatus between locations.

32. Trenching apparatus as claimed in claim 26 wherein the arm is attached to

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SUBSTITUE SHEET Rule 26 the vehicle such that when in use the body is pulled across the surface by the vehicle to minimise undertow created by rotation of the body and the cutting action of the blades in to the ground.

33. Trenching apparatus as claimed in claim 32 wherein the undertow is compensated for by the inclusion of an optional stabilising apparatus.

34. Trenching apparatus as claimed in claim 33 wherein the stabilising apparatus is a ground wheel or skid to stabilise the laterally disposed body and the vehicle pulling the body during its operation.

35. Trenching apparatus as claimed in claim 34 wherein the vehicle includes a tractor or an excavator.

36. A method of manufacturing trenching apparatus for excavating and maintaining trenches, the trenching apparatus including a body capable of being attached to a vehicle, the body being capable of rotation about its radial axis, and including a substantially open frame, and the frame including multiple digging apparata, and the trenching apparatus characterised by the digging apparata transferring either or both materials and liquids into the body from the trench being excavated and/or maintained, during rotation of the body, the method including the steps of:

a) producing a rotatable body comprising an open frame configured to complement the shape of trench required; and

b) said frame including multiple digging apparata extending from the frame; and

c) attaching the body to a pivotable arm, said arm adapted to attach to a vehicle capable of activating rotation of the body.

37. A method of manufacturing trenching apparatus for excavating and maintaining trenches as claimed in claim 36 wherein the multiple digging apparata are arranged around the frame of the body in a substantially spiral configuration.

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SUBSTITUE SHEET Rule 26

8. Trenching apparatus substantially as described herein with reference to the accompanying drawings.

A method of manufacturing trenching apparatus substantially as described herein with reference to the accompanying drawings.

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SUBSTITUE SHEET Rule 26