WO2011150474A1

WO2011150474A1 - An excavator bucket

Info

Publication number: WO2011150474A1
Application number: PCT/AU2011/000704
Authority: WO
Inventors: Derek Mulder; Murray Buhse
Original assignee: Cqms Pty Ltd
Priority date: 2010-06-04
Filing date: 2011-06-06
Publication date: 2011-12-08

Abstract

An excavator bucket comprising a generally rectangular floor. The excavator bucket also has a side wall extending from each of opposed sides of the generally rectangular floor. The excavator bucket also has a rear wall extending from a rear end of the generally rectangular floor. One or more apertures extend through each of the side walls.

Description

TITLE

"AN EXCAVATOR BUCKET" FIELD OF THE INVENTION

This invention is concerned with improvements in excavator buckets.

The invention is concerned particularly, although not exclusively, with excavator buckets comprising one or more apertures in side walls.

BACKGROUND OF THE INVENTION

Dragline excavators represent a capital expenditure of hundreds of millions of dollars with operational overheads currently around US$6,000 per hour. In order to maximize operational efficiency and return on investment, this necessitates continuous operation of a dragline apparatus 24 hours a day, 7 days a week. Apart from routine shut-downs for maintenance requirements, any reduction in operational efficiency can represent substantial annual productivity losses.

Generally speaking, most draglines are a compromise between such factors as boom length, bucket and rigging mass and bucket payload capacity. Operational efficiencies of a dragline bucket can be measured according to a number of parameters including drag energy (or specific drag energy) and total sum load of the bucket, rigging and payload where:

DRAG ENERGY = a measure of the energy required to fill a bucket of given capacity. Factors affecting drag energy include the extent of frictional engagement between internal and external bucket surfaces and earth masses within and without the bucket respectively, tooth/cutting edge configurations and the dead mass of the bucket/rigging combination. SPECIFIC DRAG ENERGY = the drag energy expended per kg of payload excavated.

TOTAL SUSPENDED LOAD (TSL) = the sum of the masses of the bucket rigging and payload.

Since the early 1900's, there have been many modifications to bucket designs and rigging configurations in an endeavour to achieve greater excavation efficiencies in terms of energy consumption and excavation rates. During the last century, bucket capacities and therefore payloads have increased from about 20 tonnes to over 100 tonnes.

Excavator bucket designs are generally of an arched or archless design with some excavator operators preferring an arched design at the expense of reduced payload to obtain a more robust bucket with lower maintenance requirements. The mass of a n archless bucket and rigging is typically less than that of an arched bucket and associated rigginglargely due to the exclusion of the arch over the front of the bucket. It is argued in some quarters that increased productivity offsets any increases in maintenance of a less robust archless bucket but, at the end of the day, the decision as to which bucket is employed is often predicated on the type of earthen material to be excavated with the archless bucket being used with softer, less aggressive, easily penetrated earth types.

The present Applicant is also the Assignee of Australian (All) Application No 2008202822. The invention defined in AU 2008202822, which relates to a heavy duty excavator bucket, was developed to provide an excavator bucket that can be conveniently used in regions with harder rock filled earth types. However, while AU 2008202822 has helped reduce some of the problems associated with excavating harder, less easily penetrated earth types, there are still a number of inconvenient problems with these heavy duty excavator buckets.

With the foregoing in mind, it is an aim of the present invention to provide an excavator bucket that overcomes or alleviates at least some of the shortcomings of prior art excavator buckets and otherwise to give consumers a convenient choice.

SUMMARY OF THE INVENTION The present has arisen after the inventors discovered that it becomes inefficient and energy consuming to have a large heavy excavator bucket under circumstances where a smaller, lighter bucket would have been preferred. Such circumstances arise when providing a new bucket where it is difficult to determine what size bucket is required to provide optimal efficiency until some actual digging has commenced.

In one broad form, the invention provides an excavator bucket comprising one or more apertures in side walls of the excavator bucket.

Advantageously, the presence of the apertures reduces the dirt pressure in the mouth of the excavator bucket during the excavation process, thereby allowing the excavated dirt to flow to the back of the bucket in a simple and effortless manner. Consequently, less drag energy is required and the fill velocity is greater leading to a significant reduction in bucket fill time with associated cost savings.

Furthermore, the use of a lighter bucket that is more suitable for excavating reduced volumes of dirt results in a reduction in specific drag energy as less energy is expended per kg of payload excavated compared to when a heavier bucket with solid side walls is used for the same payload.

According to a first aspect of the invention, there is provided an excavator bucket comprising:

a generally rectangular floor;

a side wall extending from each of opposed sides of the generally rectangular floor;

a rear wall extending from a rear end of the generajly rectangular floor; and

one or more apertures extending through each of the side walls. Preferably, each aperture extends through each respective sidewall proximal a mouth of the excavator bucket.

Suitably, each aperture extends through each respective side wall in an upper portion of each side wall.

Preferably, the one or more apertures are aligned

Suitably, each of the one or more apertures are at least partly surrounded by one or more reinforcing members.

Suitably, each of the one or more reinforcing members is formed from reinforced steel.

Preferably, one or more panels are mounted to the sidewall about one or more of the apertures to thereby adjust the size of the aperture.

In a further aspect, the invention resides in a method of adjusting the load capacity of an excavator bucket comprising side walls, said method including the step of creating one or more apertures in said side walls, to thereby adjust the load capacity of the excavator bucket.

Preferably, the step of creating the one or more apertures includes removing, excising, cutting, or otherwise eliminating at least a portion of the side walls.

Preferably, the step of adding a reinforcing member around a periphery of at least one of the apertures.

Suitably, each reinforcing member is constructed from reinforced steel.

Optionally, the method further includes the the step of mounting one or more panels to the side wall to thereby adjust the size of each of the one or more apertures. ^{' · >} .^{■ ■} Throughout this specification, unless the context requires otherwise, the words "comprise", "comprises" and "comprising" will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings wherein:

FIG. 1 shows a perspective view from above of a prior art excavator bucket;

FIG. 2 shows a perspective view from above of an embodiment of an excavator bucket; and

FIG. 3 shows a side view of the bucket of FIG. 2.

FIG. 4 shows a side view of the bucket of FIG. 2 and FIG. 3 further comprising a panel.

DETAILED DESCRIPTION OF THE DRAWINGS

Reference will firstly be made to a prior art excavator bucket shown in FIG. 1. Excavator bucket 1 comprises a cast lip 2 having spaced noses 3 Extending rearwardly from lip 2 is a plate steel floor 4 and an upwardly curved rear wall 5. Plate steel side walls 6 extend rearwardly of cast side wing members 7 extending upwardly from lip 2. Wing members 7 support replaceable wear members in the form of wing shrouds (not shown). Formed integrally with wing members 7 are drag rope bushes 10. A cast arch member 11 extends between opposed wing members 7 and supports a mounting bracket 12 for connection to a drag rope rigging assembly (not shown). A cap rail 13 fabricated from cast steel components is secured about the upper edges of the side and rear walls 6, 5 and trunnion brackets 14 are secured to reinforced trunnion mount panels 15. The trunnion brackets 14 are used for connection to a hoist rope rigging assembly (not shown).

A cast junction member 16 extends along each side of the bucket rearwardly of wing members 7 to form a smooth arcuate transition region 16a between floor 4 and side walls 6 and similarly forms a smooth arcuate corner transition region 16b between side walls 6 and rear walls 5. Junction members 16 are formed from a plurality of castings welded together to form a unitary member. Rear wall 5 includes a central transverse element 5a and forwardly directed outer elements 5b which, together with the transition region 16b form generally chamfered corners 17 at the rear of bucket 1. Between the upper edge 18 of the curved portion of rear wall 5 is an outwardly inclined rear wall portion 5c. Located on the outer surface of junction member 16 below trunnion brackets 14 are replaceable wear members 19.

Reference is now made to an embodiment of the invention shown in FIG. 2 and FIG. 3.

Apertures 8 are in each of the side walls 6, each aperture 8 is surrounded or flanked by a reinforcing member 9. Each reinforcing member 9 is formed of a strengthening material, such as reinforced steel.

Typically, apertures 8 are created in an excavator bucket 1 (such as shown in FIG. 1) "in the field" to thereby adjust the load capacity of the excavator bucket. Apertures 8 are created by excising a portion of side walls 6 using a gas axe, hand torch, steel cutting blade or the like. Reinforcing member 9 is subsequently fitted around each aperture 8, such as by welding, to thereby reinforce side walls 6 and ensure that the excavator bucket 1 remains robust during excavation.

Each of the apertures 8 are located to extend through each side wall 6 in a location of each side wall 6 proximal a mouth of the excavator bucket 1. Furthermore, each of the apertures 8 are located through an upper portion of each side wall 6.

FIG. 4 shows another embodiment of the invention in which panel 21 has been mounted to each reinforcing member 9 by fasteners (e.g. bolts) 22. The mounting of panel 21 enables a user to adjust the size of the apertures 8 and thereby adjust the volume of the excavator bucket 1.

It will be appreciated that one or more panels 21 may be mounted to each reinforcing member 9 to adjust the size of the apertures 8 to suit different conditions (e.g. increased and reduced volumes of dirt).

Accordingly, it will be appreciated that apertures 8 lighten the excavator bucket 1 and thereby decrease the dirt pressure in the mouth of the excavator bucket 1 so the excavated dirt can move more smoothly from the mouth to the back of the excavator bucket 1. As a result, less ^' drag energy is required and the fill velocity is greater leading to the excavator bucket 1 being filled in a quick and efficient manner

Moreover, the provision and use of a lighter bucket reduces the specific drag energy as less energy is required to drag a lighter bucket per kg of payload excavated compared to when a heavier bucket with solid side walls is used for the same payload.

Another advantage is that the volume of the excavator bucket 1 can be conveniently adjusted "in the field" (e.g. at an excavation site or mine), thereby eliminating the need to transport the excavator bucket 1 from the field to a manufacturing plant, replace the excavator bucket 1 with a lighter more efficient excavator bucket 1 and/or provide multiple excavator buckets 1 of different load capacities.

As will be appreciated from the foregoing, the present invention provides a superior excavator bucket, and a method of producing the same, that offers significant advantages compared to prior art excavator buckets.

It readily will be apparent to persons skilled in the art that many modifications and variations may be made to the invention without departing from the spirit and scope thereof.

Claims

1. An excavator bucket comprising:

a generally rectangular floor;

a rear wall extending from a rear end of the generally rectangular floor; and

one or more apertures extending through each of the side walls.

2. The excavator bucket of claim 1 , wherein each aperture extends through each respective sidewall proximal a mouth of the excavator bucket. 3. The excavator bucket of Claim 1 or Claim 2, wherein each aperture extends through each respective side wall in an upper portion of each side wall.

4. The excavator bucket of any one of Claims 1-3, wherein the one or more apertures are aligned.

5. The excavator bucket of any one of Claims 1-4, wherein each of the one or more apertures are at least partly surrounded by one or more reinforcing members.

6. The excavator bucket of Claim 5, wherein each of the one or more reinforcing members is formed from reinforced steel.

7. The excavator bucket of any one of Claims 1-6, wherein one or more panels are mounted to the sidewall about one or more of the apertures to thereby adjust the size of the aperture.

8. A method of adjusting the load capacity of an excavator bucket comprising side walls, said method including the step of creating one or more apertures in said side walls, to thereby adjust the load capacity of the excavator bucket. g. The method of Claim 8, wherein the step of creating the one or more apertures includes removing, excising, cutting, or otherwise eliminating at least a portion of the side walls. 10. The method of Claim 8 or Claim g, further comprising the step of adding a reinforcing member around a periphery of at least one of the apertures.

11. The method of Claim 10, wherein each reinforcing member is constructed from reinforced steel.

12. The method of any one of Claims 8-11 , further comprising the step of mounting one or more panels to the side wall to thereby adjust the size of each of the one or more apertures.