GB2565806A - Excavator bucket - Google Patents

Abstract

An excavator bucket 1 features a receptacle 2 for retaining aggregate material, where the bucket has at least one pair 7, 8 of powered compacting elements. These elements are for compacting aggregate material poured from the receptacle about a pipe in trench. In another embodiment there is provided a method of laying a pipe in a trench by placing a pipe in the trench using a placement assembly and pouring aggregate material about the pipe from the receptacle of the excavator bucket. Then the aggregate material is compacted using the at least one pair of powered compacting elements to compact the aggregate material poured from the receptacle. Optionally, the compacting elements are submergible beneath the aggregate material while the receptacle remains above the aggregate material. Optionally the compacting elements comprise elongate members extendable along their length. Optionally, a first compacting element is integrated into a housing about a first inner side wall of the excavator bucket and wherein a second compacting element is integrated into a housing about a second inner side wall of the excavator bucket, the second inner side wall facing the first inner side wall.

Description

Excavator Bucket

Field of the Invention

The present invention relates to an excavator bucket for laying a pipe in a trench and in particular to the pouring and compaction of aggregate about the pipe.

Background to the Invention

In conventional practice, pipe laying comprises the steps of excavating a trench and reinforcing the structural integrity of the trench by fitting a trench box therein. The floor of the trench may then be levelled with aggregate, for example gravel, or other suitable material. A pipe is subsequently lowered into the trench, whereupon labourers disposed within the trench manipulate the lowered pipe so as to engage the pipe with previously laid pipe sections. The remainder of the trench is infilled to completely cover the laid pipe.

Principal amongst the difficulties associated with the traditional pipe laying techniques is that trench work is extremely hazardous. The threat of injury or death to workers resulting from trench cave-ins is a recurrent possibility. Moreover, the costs associated with enacting protective measures to prevent workers in the trenches from being trapped or seriously injured in the event of trench wall collapse are considerable.

A summary of current best practice for the laying of pipes is as follows: a trench is dug to a depth of circa 150 mm below the design bottom level of the pipe to allow for the placement of a layer of crushed stone pipe bedding material beneath the pipe.

A steel protection box is placed in the trench to prevent the trench walls collapsing on the workers.

A crushed stone bedding material is then poured into the trench using an excavator or other means and the workers in the trench then manipulate this material to form the bedding layer for the pipe.

Great care must be taken to ensure that the top level of this bedding material is accurately aligned with the designed pipe gradient and the designed bottom level of the pipe and this is commonly achieved by measuring from an in-pipe laser beam which is pre-aligned to the pipe line and gradient.

The pipe is then lowered into the trench and the workers insert this pipe into a previously laid pipe and carefully adjust the pipe so it is correctly aligned along the design line and gradient.

Additional crushed stone is then lowered into the trench and the workers place this stone either side and along the length of the pipe up to the halfway level on the pipe diameter.

This side-fill stone is manipulated with a shovel or rod by inserting the tool into the gravel along both sides of the pipe thus ensuring that any voids that may exist within the stone are replaced with stone.

This is a key facet of the installation as the pipe relies on this stone to provide structural support to the pipe in the bedding and haunch zones, the bedding zone been the area underneath the pipe and the haunch zone being the area at either side of the pipe up to a level halfway up the circumference of the pipe to a level known as the springline. Improperly supported pipes may move or dislodge during and after infilling of the trench leading to additional excavation or realignment of pipes which adds considerable time and expense to the pipe laying process.

There remains a need for alternative devices capable of minimising human intervention in placing materials in a trench, thereby reducing the potential for injury resulting from trench collapse. Patent application PCT/EP2016/08243 7 describes a system for placement of a pipe in a trench and subsequent compaction of aggregate material about the pipe. The present invention seeks improvement over current compaction methods and systems.

Summary of the Invention

The present invention comprises an excavator bucket comprising a receptacle for retaining aggregate material; the bucket comprising at least one pair of powered compacting elements for compacting of aggregate material poured from the receptacle about a pipe in a trench.

This is advantageous as it provides for a single integrated device for the pouring and compaction of aggregate material about a pipe when pipe laying. As such, not only is the requirement for a work person to be in the trench for pipe laying obviated but furthermore, the requirement for separate equipment for the pouring of aggregate material and the compaction of aggregate material is also obviated. Delivery of aggregate material about the pipe can be provided by the excavator bucket and compaction can be provided by the powered compacting elements of the bucket. A typical excavator bucket does not provide for compacting of aggregate material poured from the receptacle about a pipe in a trench. Rather, simple tamping or smoothing may be done above the pipe surface. Such action is inadequate to provide the type of compaction need for reliable pipe laying and a consistent gradient. The excavator bucket of the invention greatly increases the efficiency of the pipe laying process, meaning that a given length of piping may be laid in a considerably reduced time compared to laying of the pipe and manual compaction of aggregate by workers operating in the trench. It also results in a much safer process as workers are not required to be in the trench to carry out the pipe installation. It further obviates the need for an aggregate delivery apparatus to approach a pipe trench, retreat from the trench area to be further followed by a compacting apparatus. The excavator bucket of the invention fulfils both aggregate delivery and compaction. T he compacting elements operate to ensure that no voids are left beneath the pipe in the bedding area which is often a problem with manual compaction. Furthermore, compaction is provided about the haunch of the pipe. In this manner, a reliably compacted bed and haunch layer is provided to support the pipe without the intervention of workers in the trench.

The compacting elements may be submergible beneath the aggregate material while the receptacle remains above the aggregate material. This is advantageous as it provides for efficient delivery of aggregate followed by compaction. The receptacle can be tipped to pour aggregate into the trench area and the excavator bucket manoeuvred by an excavator operator down into the trench such that the compacting elements are submerged beneath the just poured aggregate. Submerging the compactor elements in this manner provides for simultaneous compaction of the aggregate material along with filling of the void beneath the pipe being laid.

The compacting elements may comprise elongate members extendable along their length. This provides that the depth to which the compacting elements extend into the poured aggregate may be adjusted.

A first compacting element is integrated into a housing about a first inner side wall of the excavator bucket and wherein a second compacting element is integrated into a housing about a second inner side wall of the excavator bucket, the second inner side wall facing the first inner side wall. This provides for a very robust structure in which the compacting elements are protected with the housing. The compacting elements may be retracted into the housing when the excavator bucket is in use to scoop aggregate. This provides protection for the compacting elements. The compacting elements may then extend from the housing to begin compaction after pouring of the aggregate from the bucket receptacle.

The bucket may be dimensioned such that with a pipe in a trench, the first compacting element of a pair is about a first side of the pipe length and the second compacting element of a pair is about an opposite side of the pipe length. This facilitates firstly the pouring of aggregate about both sides of a pipe and further the compaction of material about both sides of the pipe simultaneously.

A surface of the receptacle may comprise a cutaway region forming an arc shaped edge on the receptacle. This is advantageous as the cutaway region allows the excavator bucket to be manoeuvred downward into a trench by an operator such that the pipe in situ rests within the cutaway region. This provides that the compacting elements can extend down along both sides of the pipe such that efficient compaction may occur about both sides of the pipe. It further obviates the need for longer compacting elements to extend downward into the trench.

The compacting elements may be moveable in a reciprocating motion for compacting of the poured aggregate about the pipe. The reciprocating motion compacts the aggregate material at the sides and under the pipe at the same time thus providing a reliably compacted bedding and haunch layer and sufficient support about the pipe sides to prevent settlement or subsequent lateral movement of the pipe.

The compacting elements may have a stroke reciprocating distance of about 50 mm. Movement of compacting elements in a reciprocating motion beneath the surface of the gravel with a piston stoke length of about 50 mm effects the urging of the gravel entirely under the pipe and also has the effect of simultaneously compacting gravel in the area surrounding the pipe. The frequency of the reciprocating motion may be adjustable if required to provide for compaction about different pipe types or for use with different aggregate types.

A method of laying a pipe in a trench may comprise:

placing a pipe in the trench using a placement assembly;

pouring aggregate material about the pipe from the receptacle of an excavator bucket; the bucket comprising at least one pair of powered compacting elements for compacting of aggregate material poured from the receptacle about a pipe in the trench;

compacting the aggregate material using the at least one pair of powered compacting elements for compacting of the aggregate material poured from the receptacle.

In this manner, a method of pipe laying is provided in which effective delivery and compaction of aggregate material may be provide by the excavator bucket. Such a method is significantly more time efficient than existing pipe laying methods which require multiple equipment types for each part of the pipe laying process. It further provides significant safety advantages as the need for personnel to be in the trench for compaction of aggregate is obviated. The method further provides for the use of less personnel for the pipe laying process, thus providing significant labour savings.

Description of the Drawings

Figure 1 is a side perspective view of the an excavator bucket of the invention

Figure 2 is a transparent side perspective view of the an excavator bucket of the invention

Figure 3 is a top down side perspective view of the an excavator bucket of the invention

Figure 4 is a transparent top down perspective view of the an excavator bucket of the invention

Detailed Description of the Drawings

The invention will now be described with reference to the accompanying drawings. Figures 1 to 4 provide perspective views of the excavator bucket of the invention view of the excavator bucket of the invention. The excavator bucket 1 of the invention comprises a receptacle 2 for retaining aggregate material. The receptacle is formed from side walls 3, 4, a rear wall 5 and a base region 6. The bucket comprises a pair of powered compacting elements 7, 8 for compacting of aggregate material poured from the receptacle 2 about a pipe in a trench. The compacting elements may comprise hydraulically, electrically or pneumatically powered pistons within a cylinder. The compacting elements are retained within housings 9, 10 along the side walls of the receptacle. The bucket further comprises a hitch 11 for attachment to a typical excavator arm (not shown). This provides that the bucket and the compacting elements may be manoeuvred by an excavator operator when attached to an excavator arm. The base region 6 also comprises a cutaway region 12 forming an arc shaped edge on the receptacle.

Apparatus in Use

Laying a pipe in a trench using the excavator bucket of the present invention comprises, in summary, placing a pipe in the trench using a placement assembly on a first excavator; pouring aggregate material about the pipe from the receptacle of the excavator bucket on a second excavator; the bucket comprising at least one pair of powered compacting elements for compacting of aggregate material poured from the receptacle about a pipe in the trench and compacting the aggregate material using the at least one pair of powered compacting elements for compacting of the aggregate material poured from the receptacle.

In further detail, laying a pipe in a trench comprises digging a trench and placing a pipe in the trench using a placement assembly on a first excavator, tor example the pipe may be placed in the trench in the manner described in patent application PCT/EP2016/082437. The bottom level of the pipe is set 150 mm above the bottom of the trench to allow space for 150 mm of aggregate, such as stone bedding material, under the pipe. It is essential to place the bedding around the pipe and compact it to a high density along its sides and underneath the pipe ίο ensure that the pipe is securely bedded and to further provide a consistent pipe gradient.

An excavator bucket according to the invention is fitted to an excavator dipper arm of a second excavator and the bucket is manoeuvred by an operator. The compacting elements are controlled by the excavator operator and are controlled firstly to be in a fully retracted or “off” position. The bucket may be manoeuvred to scoop aggregate into the receptacle 5 and further manoeuvred such that the bucket swings or tips about the hitch 11 to pour the aggregate about the pipe in the trench. The bucket may then be moved further downward into the pipe trench such that the top surface of the pipe extends into the cut away region in the base region 6 of the bucket.

The compacting elements 7, 8 are orientated into a perpendicular position relative to the pipe bed and positioned such that they are submerged beneath the aggregate material surface.

The compactor elements 7, 8 may then be activated by the operator into an “on” or extended position. In this position, the compacting elements 7, 8 are then moved along the length and both sides of the pipe by movement of the dipper arm by the operator. The compacting elements 7, 8 produce a reciprocating motion to blow or strike the aggregate material thereby simultaneously pushing the stone aggregate material under the pipe from both sides in addition to compacting the aggregate material. This forms a suitable compacted bed and haunch layer for the pipe which is at the required level for alignment with the guide pipe. The reciprocating motion compacts the aggregate material at the sides and under the pipe at the same time thus providing a reliably compacted bedding and haunch layer and sufficient support about the pipe sides to prevent settlement or subsequent lateral movement of the pipe. The installation of this pipe segment is now complete and the process may begin again with a further pipe.

The words “comprises/comprising” and the words “having/including” when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

Claims (10)

1. An excavator bucket comprising a receptacle for retaining aggregate material; the bucket comprising at least one pair of powered compacting elements for compacting of aggregate material poured from the receptacle about a pipe in a trench.

2. The excavator bucket of claim 1 wherein the compacting elements are submergible beneath the aggregate material while the receptacle remains above the aggregate material.

3. The excavator bucket of claims 1 or 2, wherein the compacting elements comprise elongate members extendable along their length.

4. The excavator bucket of any preceding claim wherein a first compacting element is integrated into a housing about a first inner side wall of the excavator bucket and wherein a second compacting element is integrated into a housing about a second inner side wall of the excavator bucket, the second inner side wall facing the first inner side wall.

5. The excavator bucket of any preceding claim, wherein the bucket is dimensioned such that with a pipe in a trench, the first compacting element of a pair is about a first side of the pipe length and the second compacting element of a pair is about an opposite side of the pipe length.

6. The excavator bucket of any preceding claim wherein a surface of the receptacle comprises a cutaway region forming an arc shaped edge on the receptacle.

7. The system of any preceding claim, wherein the compacting elements are moveable in a reciprocating motion for compacting of the poured aggregate about the pipe.

8. The system of claim 7 wherein the compacting elements have stroke reciprocating distance of about 50mm.

9. The system of claim 8, wherein the frequency of the reciprocating motion is adjustable.

10. A method of laying a pipe in a trench comprising:

placing a pipe in the trench using a placement assembly;

pouring aggregate material about the pipe from the receptacle of an excavator bucket according to claim 1;

compacting the aggregate material using the at least one pair of powered compacting elements for compacting of the aggregate material poured from the receptacle.