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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2002/022966
Kind Code:
A motorised vehicle has an arm (5) with at least one scoop-like digging bucket (10) pivotally mounted at its lower end moveable by an hydraulic ram (11). Dug material is continually removed from the bucket through a lateral inlet opening (16) by means of a screw (8), driven by a motor (9), which carries material up the arm to a discharge outlet (15). The arm may have a nibbler bar attachment and the bucket may have lateral digging extensions.

Application Number:
Publication Date:
March 21, 2002
Filing Date:
September 06, 2001
Export Citation:
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International Classes:
E02F3/06; E02F3/40; E02F7/02; (IPC1-7): E02F3/40; E02F3/06; E02F7/02
Foreign References:
Other References:
PATENT ABSTRACTS OF JAPAN vol. 006, no. 061 (M - 123) 20 April 1982 (1982-04-20)
PATENT ABSTRACTS OF JAPAN vol. 1996, no. 07 31 July 1996 (1996-07-31)
Attorney, Agent or Firm:
Craske, Stephen Allan (Patent Law Chambers 15 Queens Terrac, Exeter Devon EX4 4HJ, GB)
Download PDF:
1. Digging apparatus which includes an arm (5) having digging means (10; 31,32) at a lower end thereof, characterised in that the arm contains an auger (8) for removing material from the vicinity of the digging means.
2. Digging apparatus according to Claim 1, in which the digging means includes a scoop which is pivotally connected to the arm.
3. Digging apparatus according to Claim 2, in which the scoop is provided with opposed digging extensions for increasing its digging width.
4. Digging apparatus according to Claim 2, in which the lower end of the arm is provided with two opposed coacting scoops.
5. Digging apparatus according to Claim 1, in which the digging means includes digging teeth.
6. Digging apparatus according to Claim 1, in which the arm has a lateral inlet opening for material which is excavated by the digging means.
7. Digging apparatus according to Claim 1, in which the arm is provided with a vibrator or a gas feed to assist in movement of material along the arm.
8. Digging apparatus according to Claim 1, in which the arm has a downwardlydirected nibbler attachment mounted partway along its length.
9. Digging apparatus according to Claim 1, in which the arm is provided with means for removing material from an upper end thereof.
10. Digging apparatus according to Claim 1, in which the arm is mounted on a motorised vehicle.
DIGGING APPARATUS TECHNICAL FIELD OF THE INVENTION This invention relates to digging apparatus.

BACKGROUND The use of augers for drilling piles or similar vertical shafts is well known.

However, trenches are conventionally made using a mechanical digger having an hydraulically moved arm with a scoop-like digging bucket at the lower end. Material is removed from the trench by using the bucket to lift the excavated material, but whilst a bucket is very effective for digging and removing most kinds of debris the operation is generally time-consuming.

The present invention seeks to provide a new and inventive form of digging apparatus.

SUMMARY OF THE INVENTION The present invention proposes digging apparatus which includes an arm mounted for movement in the direction of and below the surface of the ground, the arm having digging means at its lower end for use in cutting a trench in the ground, and in which the arm contains an auger for removing material from the vicinity of the digging means.

In one form of the invention the digging means could take the form of a bucket with transversely directed teeth, which can be used with a scooping action. The bucket can also be used for lifting material from the trench, e. g large rocks which might otherwise jam the auger. It is also preferred that the digging means incorporates a lateral opening in the side wall of the auger arm.

The auger arm may be provided with a vibrator to assist in movement of material along the arm. The arm may also have a nibbler mounted part-way along its length.

Where the digging means includes a bucket, the bucket is preferably provided with opposed digging extensions for increasing the digging width.

Material may be removed from the upper end of the auger arm by means of a chute, a conveyor or a transverse blasting duct.

BRIEF DESCRIPTION OF THE DRAWINGS The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a general side view of an excavator in accordance with the invention which is provided with an auger arm; Figure 2 is a front view of part of the auger arm having a nibbler bar attachment; Figure 3 is a front view of a bucket mounted at the lower end of the auger arm; Figure 4 is a part-sectional view through a modified form of the auger arm; Figures 5 and 6 are side and bottom views of a grab attachment for use with the auger arm; and Figure 7 is a side view of another form of vehicle which is provided with an auger arm in accordance with the invention.

DETAILED DESCRIPTION OF THE DRAWINGS Fig. 1 shows an excavator of the kind known as a"backhoe loader"which includes a tractor 1 having a first upwardly-inclined arm section 2 which can be moved about a vertical axis and a second arm section 3 which can be moved about a horizontal axis by an hydraulic ram 4. The second arm section 3 is coupled to a tubular auger arm 5, about 3 to 4 metres long, which is pivoted at 6 for movement about a horizontal axis by means of a ram 7. The arm 5 contains a screw auger 8 (e. g. 300mm to 350mm in diameter) which is driven by an hydraulic motor 9 mounted at the top of the arm 5. At the bottom of the arm, a digging bucket 10 is pivotally mounted at the bottom of the arm 5 for movement about a horizontal axis by a ram 11 acting between the rear of the bucket and a pivot mounting 12 on the auger arm. The bucket is of a conventional kind having an arcuate bottom wall, a rear wall and two opposed side walls with a set of digging teeth projecting forwardly from the bottom wall.

At the top of the auger arm 5 material can be discharged via a chute 15, a conveyor, or similar means carried by the arm 5. Such a chute or conveyor could conveniently be hinged to the arm allowing it to be stowed against the arm when not in use. The chute or conveyor is preferably also mounted such that it can be swivelled to left or right for depositing excavated material on either side of the trench, either onto the ground or into a dumper truck etc.

As well as being open at the lower end the arm 5 also contains a lateral opening 16 arranged such that when digging relatively shallow trenches, say up to 2 metres deep, material which is scooped out by the bucket 10 is continuously removed by the auger and discharged at the top of the arm.

The speed of digging deeper trenches is also increased however. The material removed by the bucket can still be fed into the auger arm, but when the arm is full it can be raised to permit discharge of the material at a suitable level.

The auger can be fitted to a conventional excavator between the arm 2,3 and the bucket 10 or in place of the arm 3. The hydraulic motor 9 can be coupled up to the hydraulic lines which are normally present on the arm.

The auger attachment considerably speeds up the task of digging a trench in reasonably good ground, typically a factor of two or three.

The attachment can also reduce the cost of constructing short bore pile foundations. Such foundations include concrete piles joined by reinforced concrete ring beam. By removing the bucket 10 it is possible to form the trench and piles in one operation. Vertical movement of the auger arm 5 will allow vertical piles to be drilled, with material entering the arm through the bottom of the arm, but if the arm is raised to a suitable level and moved laterally a trench can be cut between the piles with material being removed via the side opening 16. The edges of the bottom and side openings can be provided with digging teeth or cutting blades as necessary.

When trenches are cut in tarmac surfaces it is advantageous to provide the auger arm 5 with a nibbler bar 18 as shown in Fig. 2. The higgler bar takes the form of a vertical plate 19 having spaced, downwardly directed teeth 20.

The nibbler bar 18 is mounted in the direction of digging so that when the auger arm moves vertically the teeth bite into the tarmac surface and break away small fragments in the direction of the trench. This considerably reduces the risk of inadvertently lifting large areas of tarmac during trenching.

The bucket 10 can be adapted to dig trenches of different widths by adding bolt-on wings 22,23, as show in Fig. 3. The wings are directed outwardly to increase the effective digging width of the bucket and thereby remove the need to change buckets.

The auger arm can be provided with a vibrator to assist the movement of excavated material up the arm. An add-on vibrator can be used or the motor 9 could be modified to provide a vibratory action. When digging heavy clays, movement of excavated material along the auger arm may be assisted by feeding compressed air or other gas into the arm 5.

In some cases it may be desirable to move the auger arm 5 independently of the excavator arm 2,3. As shown in Fig. 4, this can be achieved by providing the arm with an external sleeve 26 to which the arm section 3 and ram 7 are attached. The auger arm 5 is moved relative to the sleeve by a further ram 27, or equivalent means such as an hydraulic motor having a drive gear working on a rack.

The auger arm 5 can also be modified as shown in Fig. s 5 and 6. The bucket is replaced by a grab or clam attachment 30 having a pair of pivoted jaws 31 and 32 which are moved together by a ram 33. Again, material which is dug out by the jaws is carried up the arm by the auger 8.

Fig. 7 shows the auger arm fitted to a caterpillar vehicle 40. Although the auger arm can be used for conventional trenching as described above it has also been modified for blasting. Instead of discharging via a chute or conveyor the top of the arm 5 is connected to a transverse duct 41 coupled to the outlet of a gas turbine 42. Thus, material excavated at the bottom of the auger arm is fed into the duct 41 so that it is discharged at high velocity.

A safety valve 43 is provided to release excess pressure from the duct 41 should it become blocked by excavated material. Such a machine could, for example, be useful when excavating cable-laying trenches in remote areas, but it would also be useful in fighting forest fires by smothering the flames in excavated material. Material excavated from the earth poses less risk of creating steam clouds than using water jets.

It will thus be appreciated that the auger machines described above are very versatile. They can be used for trenches and general digging, piling probing and pit excavating, as well as for moving flowable solid, liquid or sludge materials. They also have potential application in fire fighting, concrete spraying, ground stabilisation etc.

It will be appreciated that the features disclosed herein may be present in any feasible combination. Whilst the above description lays emphasis on those areas which, in combination, are believed to be new, protection is claimed for any inventive combination of the features disclosed herein.


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