GB2410239A

GB2410239A - Adjustable width excavator bucket

Info

Publication number: GB2410239A
Application number: GB0401289A
Authority: GB
Inventors: Brian Mence
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-01-21
Filing date: 2004-01-21
Publication date: 2005-07-27
Anticipated expiration: 2024-01-21
Also published as: WO2005071169A1; GB2410239B; EP1725714A1; GB0401289D0

Abstract

An adjustable width excavator bucket 1 comprises a back plate 3, a pair of spaced apart side walls 2 and a width adjustment mechanism M to adjust the width between the side walls. Each side wall 2 may include a hinge 7 having a longitudinal axis and a side plate 4 attached to the hinge 7. The mechanism M may comprise a pair of arms 8, a mounting member 16 and an actuator 15, each arm 8 being attached to a respective side plate 4, the actuator 15 generating movement of the side plates 4. Each arm 8 may comprise a cam surface 13, wherein each arm 8 is pivotally mounted on the mounting means 16 such that the cam surface 13 of one arm 8 touches the corresponding cam surface 13 of the other arm 8. The mounting member 16 may be located within the bucket 1.

Description

24 1 0239

ADJUSTABLE WIDTH EXCAVATOR BUCKET

Field of the Invention

The invention relates to buckets for excavators, and in particular to a bucket the width of which can be adjusted. Such a bucket is particularly, but not exclusivelyuseful when attached to an excavator or the backhoe of a backhoe loader.

Background of the Invention

Backhoes and excavators are used to dig trenches. The width of trenches to be dug depends on the purpose of the trench. For example, if the trench is being dug in order to lay a telephone cable, the trench need not be as wide as a trench being dug to lay a foundation, or a surface water drain pipe.

To date, excavators have been provided with a number of different buckets each having a different width. When a trench of a different size is required, the bucket must be changed to the bucket whose width most closely matches the desired width of trench.

The requirement to change buckets, and to use a bucket of defined width presents a number of problems. First, it is necessary to buy a number of buckets, which is costly. Second, it is necessaryto transport the different width buckets from site to site. Third, on building sites, when it is necessaryto change the bucket, the vehicle must traverse the site to the location of the buckets, which wastes time and can cut up the site in wet conditions. Fourth, changing the buckets takes time and is a potential source of accidents (pins holding the bucket to the arm of the excavator are changed manually, and often buckets will not be stored on level sites, thereby requiring manual effort lever the bucket into a position where the holes in the bucket and arm of the excavator are aligned so that holding pins can be securelylocated in position). Fifth, the fact that buckets are of a defined \ ee;e ; ë ae width, means that trenches can only tee dug to match the particular bucket widths, resulting in some unnecessarilywide trenches being dug.

So far, attempts made to overcome some of the above-mentioned problems have concentrated on simplifying the attachment and release of buckets to the arm of the excavator.

Whilst such systems do reduce the time taken to change buckets, and remove the need for personnel to be in the region of the bucket during change over, thereby reducing the potential for accident, many of the above-identified problems are not addressed.

The invention therefore seeks to provide an improved excavator bucket.

Summary of the Invention

According to the invention there is provided an adjustable width excavator bucket as specified in Claim 1.

One aspect of the invention provides a manual mechanism for adjusting the cutting width of the bucket.

Another aspect of the invention provides a remotely operable actuator for adjusting the cutting width of the bucket.

The adjustable width excavator bucket of the invention provides numerous benefits. First, it is not necessaryto purchase or transport from site to site numerous buckets of different widths.

Second, when on site, it is not necessaryto change bucket to match a particular job, thereby removing downtime associated with moving the vehicle to the location where the desired bucket is stored and with changing the bucket. Also, the risk of accident during changing from one bucket to another is removed. Third, expensive systems for automatically coupling and uncoupling buckets to the excavator arm can be dispensed with, since the necessity to change buckets frequently will be \ e;e e removed. Fourth, any cutting width between respective maximum and minimum cutting widths can be selected, thereby avoiding the need to dump excess spoil or pour unnecessarilylarge volumes of concrete.

Brief Description of the Drawings

In the drawings, which byvayof example, illustrates embodiments of an adjustable width excavator bucket: Figure 1 is a schematic representation of an excavator bucket according to one aspect of the mventlon; Figure 2 is a plan view of the excavator bucket illustrated in Figure 1; Figure 3 is a side view of the excavator bucket illustrated in Figures 1 and 2; Figure 4 is a front view of the excavator bucket illustrated in Figures 1 to 3, with the sides of bucket parallel; and Figure 5 is a side view of a bucket according to a second embodiment of the invention.

Detailed Description of the Preferred Embodiments

Referring now to Figure 1, there is shown an excavator bucket 1 comprising planar side walls 2 and a back plate 3, which includes a substantially arcuate portion 6 and a substantiallyplanar portion 6a. The bucket is attachable to an arm of an excavator by means of a bracket assembly comprising a pair of spaced apart plates 12, each comprising apertures 13 through which pins can be passed to secure the bucket 1 to the excavator arm. The plates 12 are welded to the back plate 3.

On a front edge of each side wall 2, there is mounted a hinge 7. Also mounted to each hinge 7 is a variable width member comprising a side plate 4 and a base plate 5 connected substantially at e. '. ::: ':e e: '.: . ce. :.. :: ece right angles to one another. As can be seen from Figure 1, it is an edge of the side plate 4 that is attached to the hinge 7. The side and base plates 4, 5 each have a free edge 4a, 5a, which in use comprise part of the cutting edge of the bucket. The base plates 5 extend beneath the substantially planar section 6a of the back plate 3, the lower surface of the said planar section 6a touching or being in close relation to the upper surface of the base plate 5. Attachment members 8 fixed to the inner surface of the side plates 4 are connected to a mechanism for varying the width of the bucket which shall be described in greater detail in relation to Figure 2.

Referring now to Figures 1 and 2, a width adjustment mechanism M comprises a pair of spaced apart plates 9 connected one to another bye web 16. Mounted rotatablyin the web 16 is an externally threaded bar 15, which passes through an aperture in the back plate 3 of the bucket. An internallythreaded nut 14 is axially aligned with the afore-mentioned aperture, and fixed to the back plate 3, for example by welding. By rotating the threaded bar 15 the Stance between the plates 9 and the back plate 3 can be varied.

The mechanism M further comprises arms 8, one end of each arm being located between the said plates 9, and pivotally connected to a respective pin 10 which passing through apertures in the plates 9 and the arm 8. An edge 11 of each arm 8 is connected to the inside of one of the side plates 4, for example the edge 11 of an arm 8 maybe welded to the inside of a side plate 4 in front of the hinge 7. In the example shown in Figure 2, the apertures in the plates 9 and the arm 8 are larger than the pin 10, and are sufficientlylarge to accommodate a bearing in the form of a bush 12 that surrounds the pin 10. The bush may be made of a compressible material such as rubber, in order that shock loads experienced during a digging operation are attenuated, rather than being transmitted directly to the other components of the mechanism M In place of the bush 12, other suitable bearings could be used.

ë;.e c.e::: .e ese: e.. Each arm 8 further comprises a cam surface 13. The distance between the centres of the pins 101ocated in the plates 9, and the shape of the cam surfaces 13 of the respective arms 8 is such that the cam surfaces touch each other.

In use, when the operator wants to change the cutting width of the bucket, he attaches a tool to, and then rotates, the threaded bar 15. As mentioned above, rotating the threaded bar 15 moves the plates 9 towards and away from the back plate 3. The arms 8 are fixed to the side plates 4, which are in turn pivotally attached to the side walls 2. Moving the plates 9 away from the back plate therefore causes the arms to pivot around pins 10, and a corresponding pivoting motion of the side plates 4, thereby adjusting the width between the cutting edges of the side plates 4.

Referring again to Figure 2, it can be seen that the axes of the hinges 7 lie in a plane forward of the plane in which the axes of the pins 10 lie. This is so that as the bucket digs, the force on the cutting edges 4a and 5a cause the ends of the arms 8 located in the mechanism M to be pushed together, and therefore the cam surfaces 13 to be pushed together. In this way the load is carried largely by the arms 8, the hinges 7, the side walls 2, and the side plates 4, rather than the mechanism M itself.

With the bucket 1 configured to provide the narrowest cutting width respective side plates 2 and 4 are aligned, and the side plates 4 of opposing sides of the bucket are substantiallyparallel. As shown by the broken line illustrating the edge of the base plates 5, in the narrowest cutting width configuration, the parallel free edges of the base plates 5 touch one another. The arrow X illustrate movement of a side plate 4 and its attached base plate 5 to a wider cutting width.

From Figure 3, the position of the threaded bar 15 and the nut 14 can be seen. The bucket 1 is attached to the arm of an excavator by suitable pins passing through the apertures 13 and corresponding apertures in the excavator arm. The position of the threaded bar 15 is such that it is easily accessible for adjustment of the bucket width.

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Figure 6 illustrates a second embodiment of the invention in which the threaded bar 15 and nut 14 are replaced bye double acting short stroke hydraulic ram 20 powered by the hydraulic system of the excavator vehicle. Hydraulic fluid is delivered to the ram 20 through hydraulic hoses 21 and 22. The rnechanismM is otherwise substantiallyidentical to the mechanism M described with reference to Figures 1 to 5.

Claims

ce a. ::: c:. : if: . c. 1, e Claims 1. An excavator bucket

having an adjustable cutting width, the bucket comprising a back plate, a pair of spaced apart side walls, and a width adjustment mechanism, wherein the distance between the side walls is adjustable to very the cutting width of the bucket, and wherein the mechanism provides for adjustment of the distance between the said side walls.
2. An excavator according to Claim 1, wherein each side wall includes a hinge having a longitudinal axis and a side plate attached to the hinge for pivotal movement about the said axis, and wherein the mechanism provides for movement of the side plates about said axis to adjust the cutting width.
3. A bucket according to Claim 2, wherein the mechanism comprises a pair of arms, a mounting member and an actuator, wherein each one of the arms is attached to a respective one of the side plates, and to the mounting member, and wherein adjustment of the actuator generates the said movement of the side plates.
4. A bucket according to Claim 3, wherein each arm is fixedly attached to a respective one of the said side plates.
5. A bucket according to Maim 3 or 4, wherein each arm is pivotally connected to the mounting member.
6. A bucket according to Claim 5, wherein each arm is pivotally mounted in the mounting member about a bearing.
7. A bucket according to Claim 6, wherein the said bearing is a bush.
8. A bucket according to Claim 7, wherein the bush is made of a compressible material.
9. A bucket according to any of Maims 2 to 8, wherein each arm comprises a cam surface, and wherein each arm is pivotally mounted on the mounting means such that the said cam surface of one arm touches the corresponding cam surface of the other arm through the range of pivotal movement of the said arm |e te::: .:e : A: ce.

ace :.. : ce.
10. A bucket according to any Claims 2 to 9, wherein the actuator comprises an externally threaded bar, which passes through a co-operating infernally threaded bore, wherein one end of said bar is rotatablylocated in the mounting member.
11. A bucket according to any preceding claim, wherein the actuator comprises a piston and cylinder arrangement.
12. A bucket according to any of Claims 2 to 11, wherein the mounting member is located within the bucket in front of the back plate and behind the said longitudinal axis of the hinges.
13. A bucket according to Claim 12, wherein with the side plates opened to their widest position, the plane in which the pivot mountings of the arms lie remains between the back plate and the longitudinal axes of the hinges.
14. A bucket according to any preceding claim, wherein a base plate extends from a bottom edge of each side plate or side plate towards the centre of the bucket.
15. A bucket according to Claim 14, wherein a free edge of one base plate substantially abuts a free edge of the other base plate with the side plates in a substantiallyparallel configuration.
16. A bucket according to Claim 14 or 15, wherein another free edge of each base plate forms a cutting edge.
17. A bucket according to Claim 16, wherein a planar surface of each base plate substantially abuts a planar surface of the back plate.
18. An excavator bucket substantially es described with reference to, and as shown in, the drawings.