GB2158491A - Drainage trenching machine - Google Patents

Abstract

Trench-digging apparatus for digging a trench and filling it with drainage material in a sequential simultaneous operation comprises a main frame (14) having ground-engaging wheels. The frame (14) has in sequential order from front to rear a pair of transversely spaced cutting discs (20), a curved excavating blade (24), two tandem hoppers (28, 30) having respective delivery chutes and a compacting roller (40). The width of the blade (24), chutes and roller (40) are the same as the width between the cutting discs (20). Turf excavated by blade (24) in use passes onto a conveyor (26) for discharge. A roller (42) extending beyond each side of the trench is provided as a follower to roller (40). <IMAGE>

Description

SPECIFICATION Drainagetrenching machine The invention relates to trench-digging apparatus and is intended particularly, but not exclusively, for use in making sand slits four remedial drainage purposes on existing playing fields, sports pitches and golf courses.

In accordance with the invention, there is provided apparatus for digging a trench and filling it with drainage material in one operation, the apparatus comprising a main frame, ground-engaging means on the frame allowing the apparatus to be propelled across an area to be drained, excavating means extending belowthe level of the ground-engaging means for excavating a trench, at least one hopper carried by the main frame for holding drainage material, delivery meansforfeeding drainage material from the hopper into the trench as it is excavated, and means for compacting the drainage material in the trench.

In a preferred embodiment ofthe invention, a pair of transversely spaced cutting discs are mounted forwardly of the excavating means wherebytheturf is cut priorto excavation andthecompacting meanscom- prises a roller of width less than or equal to the trench width.

A second hopper (and associated delivery means) may be provided whereby the drainage material deposited in the trench from the first hopper is topped with a second type of material and a surface roller of width greaterthan the trench width may be mounted rearwardly ofthe compacting means. The pressure exerted bythissurface roller can be controlled bya hydraulic ram.

Preferably, the ground-engaging means comprises a pairofwheels mounted on an axle which is carried by stays pivotably mounted one on each side of the main frame. The pivotal movement of the frame relativetotheground-engaging means can be controlled bya plurality of hydraulic rams and hencethe operating depth ofthe excavating means may be varied.

Preferably also, the excavating means comprises a curved blade in conjunction with an elevating conveyorwherebyexcavated material can be deposited in a trailer or such running alongside the apparatus, or into a container carried on said apparatus.

An embodiment ofthe invention will now be described with reference to the accompanying drawings, in which Fig. lisa side elevation of an apparatus according to the present invention for digging a trench and filling same with drainage material; Fig. 2 is a partially cut-away, simplified schematic perspective view of the invention; and Fig. 3 is a perspective view of the apparatus shown hitched to a tractor and in which a main frame is pivoted relative to an axle.

Referring nowto the drawings, a trenching apparatus or machine includes a two-part axle 8 carried by two stays 10 pivotably mounted (at 12), one on either side of a main frame 14 ofthe machine, and each part carrying a ground-engaging wheel. The pivotal movement ofthe stays 12 relative to the frame 14 is controlled by two laterally mounted hydraulic rams 16. Belowthe frame 14, two transversely spaced skids 18 are carried by a sub-frame (not shown) mounted on the frame 14for vertical movement relative thereto.

The vertical movement ofthe skids 18 is guided by uprightslideways (not shown) mounted ontheframe 14 towards the rear end of the skids 18. The slideways are provided with upper limit stops (not shown).

Mounted on and between the skids 18 are two transversely spaced cutting discs 20 with their lower edges projecting below the bottom surfaces ofthe skids 18. The cutting discs 20 serve to cut the grass layer and prevent tearing oftheturf during excavation.

For sand slitting operations of the type previously described, the discs are typically spaced 2 inches apart (but can be only 1 " apart) and cut 3-4 inches into the ground.

Rearwardly of the discs 20 and between the skids 18, excavating means in the form of an excavator blade 22 is mounted on the frame 14, having a width equal to the spacing of the discs 20. Upward movement of the skids 18 relative to the frame 14 allows the excavator blade 22 to project below the bottom surface of the skids 18. The upper limit stops of the slideways limit this upward movement and define the operating depth of the excavator blade 22 (14 inches in this case).

The front face 24 ofthe blade 22 is shaped to form a pathway along which excavated material is fed onto a slatted beltconveyor 26 for disposal into a trailer, or such being driven alongside the machine, or into a container, e.g. a skip, provided as a load-bearing surface on the frame 14. The upper flight ofthe belt conveyor 26 is enclosed by sidewalls 27 and a flexible cover 50 (Fig. 3) secured by cord to the sidewalls thereover serves to prevent material from falling other than downwards.

On top oftheframe l4andtothe rearofthe excavator blade 22 there are mountedfirstand second hoppers 28 and 30, one behind the other. The hoppers 28 and 30 contain first and second filling materials 36 and 38 (gravel and sand for example) which are deposited in the newly excavated trench via delivery chutes 32 and 34 so thatthetrench isfilledwith material 36 from the first hopper 28, topped with material 38 from the second hopper30 as shown in Fig. 1.

Immediately behind the second delivery chute 34, there is mounted compacting means in theform of a roller40 of width equal to the trench width which serves to compactthefilling-materials36 and 38 inthe trench and behind this roller 40 atthe rear end ofthe machine is a wider surface roller 42 carried by a sub4rame 44 which is pivotably mounted atthe rear end oftheframe 14. The pressure exerted on the surface by the roller 42 is controlled by a hydraulic ram 46. The elongate brush members 52 are provided, one on each side of roller4O and converge towards the rear of said rollerto brush sand lying on the ground on each lateral side of the trench into the trench priorto being rolled by roller42.

Atthe front end ofthe frame 14, a towbar48 is provided wherebythe machine can be towed behind a prime-mover such as a tractor (Fig. 3).

When the machine is not in use, or when in transit, the hydraulic rams 16 are extended as shown in Fig. 3 so thattheframe 14 pivots about the point 12 and the skids 18, the cutting discs 20, the excavator blade 22 and the roller 40 and 42 are held clear of the ground, and, obviously, the delivery chutes 32 and 34 are closed.

To commence slitting,the skids 18 are first moved downwards until they are level with the bottom ofthe excavator blade 22. The machine is then moved forward and the hydraulic rams 16 are retracted so thattheframe 14 swings down towards the horizontal allowing the cutting discs to begin cutting theturf. At the same time, the skids 18 are moved up the vertical slideways so that the excavator blade 22 projects belowthe skids 18 and begins removing turf on a progressively deepening scale. The upward move ment ofthe skids is eventually arrested by the limit stops on the vertical slideways thus defining the depth of the trench. The skids 18 perform an additional function by preventing the edges ofthe trench being cut raggedly.

Theforward movementofthe machinecausesthe excavated material to be forced up the shaped pathway on the frontface 24 of the excavator blade 22 whence it is fed onto the belt conveyor 26 for disposal.

On commencement of excavation, the delivery chutes 32 and 34 are opened so thatthe newly excavated trench is filled and topped as previously described and,finally, as the machine moves forward the filling material is compacted by the first roller 40 and the surface rolled by the second roller 42, completing the operation.

Although the embodiment hereinbefore described is intended fortowing, the invention could obviously be modified so as to be self-propelled.

Means to vibrate the machine, orat leastthe discs 20 may be provided to assist in the cutting operation.

The machine may be modified to lay a drainage pipe inthetrench immediately after being excavated and priorto being filled and topped.

Claims (12)

1. Apparatus for digging a trench and filling it with drainage material in one operation,the apparatus comprising a main frame, ground-engaging means on the frame allowing the apparatus to be propelled across an area to be drained, excavating means extending belowthe level ofthe ground-engaging meansforexcavating a trench, at least one hopper carried by the main frame for holding drainage material, delivery means forfeeding drainage material from the hopper into the trench as it is excavated, and means forcompacting the drainage material in the trench.

2. Apparatus as claimed in Claim 1, wherein a pair oftransversely spaced cutting discs are mounted forwardly of the excavated means whereby the turf is cut prior to excavation.

3. Apparatus as claimed in Claim 1 or 2, wherein the compacting means comprises a rollerofwidth less than or equal to the trench width.

4. Apparatus as claimed in Claim 1,2 or 3, wherein a second hopper (and associated delivery means are provided whereby the drainage material deposited in the trench from the first hopper is topped with a second type of material

5. Apparatus as claimed in Claim 1,2,3 or4, wherein a surface roller of width greaterthan the trench width is mounted rearwardly ofthe compacting means.

6. Apparatus as claimed in Claim 5, wherein a hydraulic ram is provided to control pressure exerted bythesurface roller.

7. Apparatus as claimed in any one of the preced ingClaims,whereintheground-engaging means comprises a pair of wheels mounted on an axle which is carried by stays pivotably mounted one on each side ofthe main frame.

8. Apparatus as claimed in Claim 7, wherein the pivotal movement ofthe frame relative to the groundengaging means is controlled by a plurality of hydraulic rams and hence the operating depth ofthe excavating means is variable.

9. Apparatus as claimed in any one of the preceding claims, wherein a curved blade in conjunction with an elevating conveyor whereby excavated material can be deposited in a trailer or such running alongside the apparatus, or into acontainercarried on said apparatus.

10. Apparatus as claimed in any one of Claims 2 to 9, wherein means to vibrate at least the cutting discs are provided.

11. Apparatus as claimed in Claim 9 or 10 wherein pipelaying means is provided between the excavating blade and the first hopper.

12. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.