WO2011041844A1

WO2011041844A1 - Trench cutting machine

Info

Publication number: WO2011041844A1
Application number: PCT/AU2010/001324
Authority: WO
Inventors: Edward Wechner
Original assignee: Tcm Pty Ltd
Priority date: 2009-10-09
Filing date: 2010-10-08
Publication date: 2011-04-14

Abstract

A trench cutting device (10) comprises a housing (12) a first chain loop (56) mounted on a primary sprocket (52) and a second chain loop (60) arranged adjacent to the first chain loop (56) and mounted on a secondary sprocket (54), wherein the primary sprocket (52) is mounted at an oblique angle to the secondary sprocket (54) such that a cutting section (66, 70) of the chain loops (56, 60) is at least as wide as the housing (12) and wherein a return section (64, 68) of the chain loops (56, 60) is sufficiently narrower than the housing (12) to allow the return section (64, 68) to travel within the housing (12).

Description

Trench cutting machine

Field of the Invention

The present invention relates to a trench cutting machine for cutting a trench in the ground. In particular, the present invention relates to a trench cutting machine for use in the process of cutting a trench in the ground and filling the trench with concrete to create a sub-surface concrete wall.

Background of the Invention

Trench cutting machines are used in construction projects to cut trenches in the ground for filling with concrete. When the concrete sets, this forms a sub-surface concrete wall that can then be excavated. When excavated on a single side of the concrete wall, this allows an earth retaining concrete wall to be formed in the ground before excavation takes place, greatly simplifying both the excavation process and the erection of the concrete wall.

Trench cutting machines typically employ a single cutting chain mounted via a drive sprocket at the top and an idler sprocket at the bottom and housed in a casing. Cutting elements on the cutting chain cut a trench in the ground as the cutting elements move upwardly from the idler sprocket to the drive sprocket and the cutting chain returns from the drive sprocket down to the idler sprocket within the casing. In order that the trench being cut is wide enough to accommodate the casing, the cutting elements must extend at least the full width of the casing. However, in order to allow the cutting chain to return to the idler sprocket within the casing, the cutting chain must be narrower than the casing. In order to achieve this outcome, the machines typically have flexible cutting elements that are able to fold or collapse inwardly to reduce the overall width of the cutting chain as it returns within the casing.

Flexible or foldable cutting elements are complex mechanisms, comprising multiple moving components and therefore are expensive to produce and present significant difficulties in terms of reliability and maintenance. The flexible cutting elements are known to fail or jam during operation, which can result in further damage to the machine and downtime. In operation, a trench cutting machine is lowered vertically, cutting a hole in the ground to the desired depth of the trench. The trench cutting machine is then driven in a forward, horizontal direction to cut the desired length of trench. In order to cut the vertical hole, trench cutting machines typically have an auxiliary cutting chain driven by an auxiliary drive assembly, located at the base of the trench cutting machine. The auxiliary drive assembly typically includes a planetary gear case, a bevel gear case and a plurality of sprockets and chains. These components add significantly to the cost and complexity of the machine and present further difficulties in terms of reliability and maintenance.

Trench cutting machines may be provided with an independently operable concrete chute mechanism that can pour wet concrete or cement into the trench, as the trench is cut in the horizontal direction. This allows the process to be achieved in one pass by a single machine. However, the addition of the concrete chute mechanism to the trench cutting machine makes the operation of the machine much more complex.

Object of the Invention

It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages, or to provide a useful alternative.

Summary of the Invention

In a first aspect, the present invention provides a trench cutting device comprising:

a housing having a front end and a rear end;

a first chain loop having a first chain cutting section arranged at the front end of the housing and a first chain return section extending within the housing; and

a second chain loop arranged adjacent to the first chain loop, the second chain loop having a second chain cutting section arranged at the front end of the housing and a second chain return section extending within the housing;

wherein the first and second cutting sections are substantially parallel and sufficiently spaced apart such that a cutting width of the cutting sections is at least as wide as the housing and wherein the first and second return sections are substantially parallel and sufficiently close together such that a return width of the return sections is sufficiently narrower than the housing to allow the return sections to travel within the housing. In a preferred embodiment, the first chain loop is mounted on a primary sprocket and the second chain loop is mounted on a secondary sprocket, wherein the primary sprocket is mounted at an oblique angle to the secondary sprocket.

Preferably, the first and second chain loops comprise a plurality of chain links and a series of chain teeth spaced along the length of each chain loop, the chain teeth being wider than the chain links, wherein the position of the chain teeth on the first chain loop are staggered relative to the position of the chain teeth on the second chain loop, such that the chain teeth of the first and second chain loops overlap along the first and second chain return sections.

In a preferred embodiment, the trench cutting device further comprises:

a gear case adapted to drive rotation of the primary sprocket;

a primary face gear mounted to the primary sprocket; and

a secondary face gear mounted to the secondary sprocket, the secondary face gear adapted to mesh with and be driven by the primary face gear.

Preferably, the trench cutting device further comprises:

a concrete chute arranged at the rear end of the housing and isolated from the first and second chain loops by a rear divider, the concrete chute adapted to deliver concrete into the trench as the trench cutting device cuts a trench in the ground.

Further preferably, the trench cutting device further comprises a propulsion device having: a drive cylinder having a push rod;

a scissor linkage having a forward pivot arm pivotally mounted at first end to the push rod and at a second end to a fixed pivot point on the chain guide and a rear pivot arm pivotally mounted at a first end to the push rod and at a second end to the rear divider.

Further preferably, the rear divider comprises a fixed rear plate, a flexible push plate and a spade.

In a preferred embodiment, the trench cutting device further comprises a chain guide adapted to constrain the path of the chain loops over the return sections. Preferably, the trench cutting device further comprises a chain guide shoe adapted to guide the chain loops around a base of the trench cutting device and converge the chain loops between the cutting sections and the return sections.

In a second aspect, the present invention provides a trench cutting and concreting machine comprising:

a vehicle body having a support arm;

a trench cutting device according to the first aspect mounted on the support arm; and a drive mechanism adapted to drive rotation of the primary sprocket.

Brief Description of the Drawings

A preferred embodiment of the invention will now be described by way of specific example with reference to the accompanying drawings, in which:

Fig. 1 is a cross-sectional view of a trench cutting device;

Fig. 2 is a plan view of the trench cutting device of Fig. 1; and

Fig. 3 is a plan view of the drive mechanism of the trench cutting device of Fig. 1.

Detailed Description of the Preferred Embodiments

A trench cutting device 10 is depicted in partial cross-section in Fig.l, having a housing 12 with a front end 14 and a rear end 16. The housing 12 comprises an opposing pair of side plates 18 joined by a rear plate 20 at the rear end 16, a chain guide 22 forward of the rear plate 20 and a chain guide shoe 24 at the base of the housing 12.

A cutting chain assembly 26 is mounted partially within the housing 12 at the front end 14. The cutting chain assembly 26 is mounted on a drive sprocket assembly 28 at the top of the housing 12 and passes through the chain guide 22 and the chain guide shoe 24. The chain guide 22 guides the cutting chain assembly 26 as it travels from the chain guide shoe 24 through the housing 12 to the drive sprocket assembly 24.

A flexible push plate 30 extends from a lower end of the rear plate 20, together forming a rear divider that extends to a spade 32 located at the base of the housing 12 at the rear end 16. A concrete chute 34 is formed at the rear end 16 of the housing 12 by the side plates 18, the rear plate 20, the push plate 30 and the spade 32. A propulsion device comprising drive cylinder 36, having a push rod 38, is mounted on the housing 12, rearward of the drive sprocket assembly 28. The push rod 38 is coupled to a scissor linkage 40, which has a forward pivot arm 42 pivotally mounted at a first end to the push rod 38 and at a second end to a fixed pivot point 44 on the chain guide 22 and a rear pivot arm 46 pivotally mounted at a first end to the push rod 38 and at a second end to the flexible push plate 30.

As shown in Fig. 2, the cutting chain assembly 26 is mounted on a drive mechanism 50, having a primary sprocket 52 and a secondary sprocket 54. The cutting chain assembly 26 comprises a first chain loop 56, having chain teeth 58, mounted on the primary sprocket 52 and a second chain loop 60, having chain teeth 62, mounted on the secondary sprocket 54. The chain teeth 58, 62 are wider than the chain links that form the chain loops 56, 60 and are integrally formed with the chain links.

The first chain loop 56 extends from the primary sprocket 52 along a first chain return section 64, guided within the chain guide 22, to the chain guide shoe 24 and then extends from the chain guide shoe 24, along a first chain cutting section 66 at the front end 14 of the housing 12, back to the primary sprocket 52. Similarly, the second chain loop 60 extends from the secondary sprocket 54 along a second chain return section 68, guided within the chain guide 22, to the chain guide shoe 24 and then extends from the chain guide shoe 24, along a second chain cutting section 70 at the front end 14 of the housing 12, back to the secondary sprocket 54. The chain guide 22 is shaped to accommodate the propulsion device without occupying a large volume of space in the housing 12.

As best shown in Fig. 3, with the chain loops and housing omitted, the primary sprocket 52 is mounted on a primary bearing housing 72 and is driven to rotate by the gear case 74. The secondary sprocket 54 is mounted on a secondary bearing housing 76 such that the primary sprocket 52 is mounted at an oblique angle to the secondary sprocket 54. The primary sprocket 52 is provided with a primary face gear 78 and the secondary sprocket 54 is provided with a secondary face gear 80 that is adapted to mesh with the primary face gear 78. In operation, the trench cutting device 10 is typically mounted to the arm of a support vehicle, such as an excavation machine. The gear case 74 of the trench cutting device 10 is powered to drive rotation of the primary sprocket 52. As the primary face gear 70 rotates with the primary sprocket 52, the secondary face gear 80 is driven by the primary face gear 78 and in turn drives rotation of the secondary sprocket 54.

The support vehicle is used to lower the trench cutting device 10 onto the ground, so that the chain teeth 58, 62 of the chain loops 56, 60 engage the ground and dig a vertical hole in the ground, into which the trench cutting device 10 is continually lowered. Once the hole has been dug to the desired depth of the trench, wet concrete is poured into the concrete chute 34, which presses against the flexible push plate 30.

By expanding the drive cylinder 36, which in turn expands the scissor linkage 40, the rear pivot arm 46 presses the flexible push plate 30 away from the chain guide 22 and against the concrete in the concrete chute 34. This forces the trench cutting device 10 forward and presses the chain teeth 58, 62 into the ground forward of the trench cutting device 10, along the chain cutting sections 66, 70, advancing the trench cutting device 10 in the forward direction and cutting a trench as it advances.

Concrete is added via the concrete chute 34 as the trench cutting device 10 advances and as the drive cylinder 36 is cyclically retracted and expanded, maintaining constant forward pressure on the trench cutting device 10. The concrete is isolated from the interior of the housing 12 by the spade 32 and the rear divider, comprising the push plate 30 and the rear plate 20.

As best shown in Fig. 2, because the primary sprocket 52 is mounted at an oblique angle to the secondary sprocket 54, the chain cutting sections 66, 70 are spaced further apart than the chain return sections 64, 68. Further, the chain teeth 58 of the first chain loop 56 are staggered relative to the position of the chain teeth 62 on the second chain loop 60 such that the chain teeth 58, 62 of the chain loops 56, 60 overlap along the chain return sections 64, 68.

This means that the return width of the chain loops 56, 60 is narrower than the width of the housing 12 along the chain return sections 64, 68 allowing the chain loops 56, 60 to pass within the side plates 18 of the housing 12, and that the cutting width of the chain loops 56, 60 is wider than the width of the housing 12 along the chain cutting sections 66, 70, so that the trench cut by the chain cutting sections 66, 70 is sufficiently wide to accommodate the housing 12.

A primary advantage of the trench cutting device is that the cutting chain assembly has simple integrally formed chain teeth with a chain cutting section that is sufficiently wide to cut a trench wide enough to accommodate the housing and a chain return section that is sufficiently narrow to be accommodated within the housing. This avoids the need for complex foldable or flexible chain teeth that collapse inwardly to allow the chain return section to be sufficiently narrow to pass within the housing. This in turn improves reliability and reduces manufacturing costs for the trench cutting device.

A further advantage of the trench cutting device is that, in order to commence the trench cutting process, a vertical hole can be dug with the same cutting chain assembly that will cut the trench in the forward direction. This obviates the need for a separate cutting chain and sprocket array mounted and driven at the base of the housing to cut the vertical hole.

A further advantage of the trench cutting device is that the concrete chute is incorporated as an integral component of the trench cutting device. This greatly simplifies operation of the device, as a user does not have to separately control a concrete delivery device while operating the trench cutting device.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

CLAIMS:

1. A trench cutting device comprising:

a housing having a front end and a rear end;

wherein the first and second cutting sections are substantially parallel and sufficiently spaced apart such that a cutting width of the cutting sections is at least as wide as the housing and wherein the first and second return sections are substantially parallel and sufficiently close together such that a return width of the return sections is sufficiently narrower than the housing to allow the return sections to travel within the housing.

2. The trench cutting device of claim 1 wherein the first chain loop is mounted on a primary sprocket and the second chain loop is mounted on a secondary sprocket, wherein the primary sprocket is mounted at an oblique angle to the secondary sprocket.

3. The trench cutting device of claim 2 wherein the first and second chain loops comprise a plurality of chain links and a series of chain teeth spaced along the length of each chain loop, the chain teeth being wider than the chain links, wherein the position of the chain teeth on the first chain loop are staggered relative to the position of the chain teeth on the second chain loop, such that the chain teeth of the first and second chain loops overlap along the first and second chain return sections.

4. The trench cutting device of claim 3 further comprising:

a gear case adapted to drive rotation of the primary sprocket;

a primary face gear mounted to the primary sprocket; and

5. The trench cutting device of claim 4, further comprising:

6. The trench cutting device of claim 5, further comprising a propulsion device having:

a drive cylinder having a push rod;

7. The trench cutting device of claim 6, wherein the rear divider comprises a fixed rear plate, a flexible push plate and a spade.

8. The trench cutting device of claim 1, further comprising a chain guide adapted to constrain the path of the chain loops over the return sections.

9. The trench cutting device of claim 1, further comprising a chain guide shoe adapted to guide the chain loops around a base of the trench cutting device and converge the chain loops between the cutting sections and the return sections.

10. A trench cutting and concreting machine comprising:

a vehicle body having a support arm;

a trench cutting device according to claim 1 mounted on the support arm; and a drive mechanism adapted to drive rotation of the primary sprocket.