EP1753922A1

EP1753922A1 - Excavating bucket and method for digging using such an excavating bucket

Info

Publication number: EP1753922A1
Application number: EP05744554A
Authority: EP
Inventors: Wilhelmus Maria Hoevenaars
Original assignee: Koninklijke KPN NV
Current assignee: Koninklijke KPN NV
Priority date: 2004-05-28
Filing date: 2005-05-30
Publication date: 2007-02-21
Also published as: WO2006021244A1

Abstract

The invention relates to an excavating bucket (100, 150) comprising a main plate and a connector (102). The connector is arranged to connect the excavating bucket to an excavator (10). The excavating bucket (100, 150) is arranged for performing a digging movement, the digging movement comprising a rotational movement about a rotational axis (R). The main plate is formed by at least a first and a second portion (111, 112) having a first and second front edge (121, 122), where a first distance between the first edge (121) to the rotational axis (R) substantially differs from a second distance of the second edge (122) to the rotational axis (R).

Description

Excavating bucket and method for digging using such an excavating bucket

Field of the invention

The invention relates to an excavating bucket comprising a main plate and a connector, the connector being arranged to connect the excavating bucket to an excavator, the excavating bucket being arranged for performing a digging movement, the digging movement comprising a rotational movement about a rotational axis. The invention further relates to a method for digging using such an excavating bucket.

Background of the invention

At the moment a lot of different cables and pipelines are being buried beneath the surface of the earth. These cables and pipelines are used by different companies and public services, for e.g. power transport, telecommunication, television signal, water supply.

Every time one of the companies involved has to add new cables or pipelines or has to replace these cables or pipe lines, the surface needs to be opened and a trench is dug. Laying cables and pipelines of different companies can be combined. Especially when in construction areas with new buildings, cables and pipelines need to be put in the soil at the same time. Different local authorities have different rules for digging trenches and laying cables and pipelines. All these different rules have in common that they specify at what depth in the soil certain cables need to be positioned.

Usually a relatively deep trench is dug, for instance with a depth of approximately 1,2 metres. On the bottom of the trench the heavier pipelines are placed, such as for instance pipes for the water supply. After placing these pipelines some of the soil is put back in the trench and next, for instance, cables for electricity and pipes for gas supply are placed. These may for instance be positioned at a depth of approximately 0,8 metres. After this, the trench is further filled with soil until it has a depth of approximately 0,6 metres. Then, telecommunication cables may be placed. Finally, the trench is closed. As a result of this procedure, all cables are placed in the trench at different levels and the trench can be closed. The process described above is a time consuming process. A relatively large amount of soil has to be moved, which takes time and is thus relatively expensive. Also the trench can not be closed at once, but is closed in steps. According to the example given above, the equipment for digging, i.e. the excavator or trencher, needs to be moved to each position along the trench four times : once for digging the trench and three times for closing the trench in steps. This makes the procedure described above relatively time consuming.

Furthermore, after the trench is closed, the exact location of the different cables and pipes in the trench is not always clear, i.e. it is not always clear where each cable or pipeline is exactly placed in the trench, in particular in the horizontal direction perpendicular to the direction in which the trench extends. This may result in digging accidents in which, for instance, telecommunication cables are damaged when digging for the water supply.

In conclusion, according to the state of the art, laying cables and/or pipes at different depths in the soil is relatively expensive and time consuming, and leads to obscurity about where each cable or pipeline is located exactly.

SUMMARY OF THE INVENTION

Object of the invention is to provide an apparatus and method that allows laying cables and/or pipes at different depths in the soil in a relatively cheap and fast way. In order to obtain this object, the invention provides a system as defined in the outset, characterized in that the main plate is formed by at least a first and a second portion having a first and second front edge, where a first distance between the first edge to the rotational axis substantially differs from a second distance of the second edge to the rotational axis. As a result of the different distances between the first and second edge with respect to the rotational axis, performing a digging movement results in a trench comprising a first and second part, having different depths. The term substantially as used here means that the first and second part of the trench can be used to lay cables and/or pipes at different levels in the soil. The rotational axis may run through the connector. The first and second portion of the main plate can have different curvatures. The first distance of the first edge to the rotational axis and the second distance of the second edge to the rotational axis can differ with at least 0,05 metre. It will be understood that the difference between the first and second distance could have any suitable value, depending on the shape of the trench that needs to be dug. The excavating bucket can further comprise a third portion having a third front edge, where the distance between the third front edge to the rotational axis substantially differs from the distance between at least the first or second edge to the rotational axis. This has the advantage that the trench that is digged with the excavating bucket will have three parts with different depths. The excavating bucket can further comprise at least one intermediate plate having an intermediate edges being provided in between the first, second portion. In a preferred embodiment at least one connection between a front edge and an intermediate edge is provided by a rounded corner. This has the advantage that the soil of the digged trench will collaps less easily.

According the another aspect of the invention a method for digging a layered trench using an excavating bucket according the the invention is disclosed. This method has the advantage that different cables and pipes can be placed on the different layers of the trench, without the need of digging various trenches .

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained with reference to some drawings which are only intended to illustrate the present invention and not to limit its scope which is only limited by the appended claims. Fig. 1 schematically depicts an excavating bucket according to the prior art;

Fig. 2 schematically depicts an excavator according to the prior art;

Fig. 3 schematically depicts a perspective view of an excavating bucket according to an embodiment of the invention;

Fig. 4 schematically depicts a cross-sectional view of an excavating bucket according to an embodiment of the invention; and

Fig. 5 schematically depicts a cross-sectional view of an excavating bucket according to an alternative embodiment of the invention.

DESCRIPTION

Fig. 1 shows an excavating bucket 1 according to the prior art. The excavating bucket 1 as shown in Fig. 1 comprises a connector 2, arranged for connecting the excavating bucket 1 to an excavator or trench digger 10, schematically shown in Fig. 2. The excavator 10 is provided with a moveable arm 11 arranged for connection to the connector 2 of the excavating bucket 1. The moveable arm 11 can be moved by the excavator 10 in such a way that a hole or trench can be dug in soil 20.

In use, the excavating bucket 1 is connected to the moveable arm 11 of the excavator 10 in such a way, that the excavating bucket 1 can perform digging movements. These digging movements may comprise a rotation about a rotational axis R, as indicated in Fig. 1. The rotational axis R may run through the connector 2, as shown in figures 1 and 2. However, the excavating bucket 1 may also be in a fixed position with respect to the moveable arm 11, in which case the rotational axis R is positioned at another location, for instance, in the moveable arm 11, as will be understood by a skilled person. As can be seen in Fig. 1, the excavator bucket 1 comprises two side plates 7, 8 and one main plate 9, provided in between the side plates 7, 8. As can be seen in Fig. 1, main plate 9 is a curved plate. The three plates 7, 8, 9 define an interior space of the excavating bucket 1.

The interior space of the excavating bucket 1 has an opening that is defined by four edges 3, 4, 5, 6. Two side edges 4, 5 are substantially parallel with respect to each other and form an edge of the first, respectively second side plate 7, 8. The two further edges, front edge 6 and back edge 3 form edges of the main plate 9.

When digging a trench, the excavating bucket 1 is moved to the surface of the soil 20 and the front edge 6 will be the first part of the excavating bucket 1 that comes in contact with the soil 20. The front edge 6 is then pushed in the soil 20 by making a suitable movement of the excavating bucket 1. This suitable movement may comprise a rotation about the rotational axis R.

In order to make the movement of the front edge 6 in the soil relatively smooth, the front edge 6 may be provided with teeth (not shown) . When digging the trench, the interior space of the excavating bucket 1 is filled with soil that can be transported away, such that a hole or trench is formed in the soil 20. It will be understood that the maximum depth of the hole that can be created by one digging movement of the excavating bucket 1 is limited by the distance between the front edge 6 and the back edge 3.

Fig. 3 shows an excavating bucket 100 according to an embodiment of the invention. The excavating bucket 100 comprises a connector 102, arranged for connecting the excavating bucket 100 to an excavator or a trencher 10. Similar to the excavating bucket 1 described with respect to Fig. 1, the excavating bucket 100 comprises a plurality of plates and edges, that define an interior space of the excavating bucket 100. According to the embodiment shown in Fig. 3, when connected to a moveable arm, a rotational axis R is provided that runs through the connector 102. It will however be understood that the rotational axis R may also be positioned somewhere else, for instance, somewhere along the moveable arm of the excavator 10.

Similar to Fig. 1, the excavating bucket 100 comprises two side plates 107, 108 and two side edges 104, 105 that form the edge of the two side plates 107, 108 respectively. The excavating bucket 100 further comprises a back edge 103, similar to Fig. 1.

The main plate of the excavating bucket 100 is divided in a first, second and third portion 111, 112, 113, that each extend between the back edge 103 and a first, second and a third front edge 121, 122, 123 respectively. The first, second and third portions 111, 112, 113 are bended plates, but each portion has a different curvature. In between the first, second and third portions 111, 112, 113, intermediate plates 114, 115 are provided, having intermediate edges 131, 132 respectively. These intermediate edges 131, 132 are preferably parallel to the side edges 104, 105.

As can be seen in Fig. 3, as a result of the different- curvatures of the first, second and third portions 111, 112, 113 of the main plate, the distance between the rotational axis R and the first, second and third front edge 121, 122, 123 differ. Fig. 3 clearly shows that in this case, the difference in distance could also be defined by comparing the distance between the first, second and third front edge 121, 122, 123 to the back edge 103, or the connector 102. When a trench is dug with the excavating bucket 100, a trench 200 will be formed in the soil 20 having a cross section as substantially shown in Fig. 4. Trench 200 has a shape that substantially corresponds with the side edges 104, 105, the front edge 121, 122, 123 and intermediate edges 131, 132 of the excavating bucket 100.

The trench 200 has side walls 204, 205 and intermediate walls 231, 232 that correspond with side edge 104, side edge 105 and intermediate edges 131, 132 respectively. The trench 200 further has base surfaces 221, 222, 223 that correspond with front edges 121, 122, 123 respectively.

It will be understood that the exact cross-sectional shape of the trench 200 does not perfectly correspond to the shape of the excavating bucket 100, as this depends of the characteristics of the soil 20. In case a trench 200 is dug in a sandy soil, the substantially side walls 204, 231, 232, 205 of the trench 200 may partially collapse, rounding of the corners of the cross sectional shape of the trench. Digging a trench in a clay soil will probably form a trench 200 having relatively sharp corners .

The shape of the excavating bucket 1, i.e. the length of the front edges 121, 122, 123, side edges 104, 105 and intermediate edges 131, 132 could be chosen in such a way that the collapsing of the side walls 204, 231, 232, 205 is anticipated. It may for instance be possible to make side edges 132 and 105 longer, such that after collapsing of the corresponding side walls 232, 205 the depth of base surface 223 is at the desired depth.

The general cross-sectional shape of the trench 200 will substantially correspond with the shape of the excavating bucket 100. This allows for laying cables and/or pipes at different levels in the soil 20, without performing intermediate actions, such as digging or (partially) filling up the trench. The cables and/or pipes 341, 342, 343, 344, 345 are schematically indicated in Fig. 4.

As can be seen in Fig. 3 and 4, the excavating bucket 100 may be provided with bulges 141, 142, 143, 144, 145. These bulges 141, 142, 143, 144, 145 provide the base surfaces 221, 222, 223 with grooves in which the cables and/or wires 341, 342, 343, 344, 345 can easily be placed, as can be seen in Fig. 4. Of course, the bulges 141, 142, 143, 144, 145 may also be formed otherwise, for instance, by providing the front edges 121, 122, 123 with a bend. Also, the cables and/or pipes laid at different depths in the soil are never positioned right above each other. This minimizes the risk of digging accidents, such as damaging e.g. a cable, when digging for e.g. a pipe that is positioned at a lower level in the soil than the cable.

Depending on the desired cross sectional shape of the trench, the shape of the excavating bucket 100 can be designed. Of course, many alternative shapes can be conceived. Instead of dividing the main plate in three portions, the main plate may be divided in any desired number of portions.

The difference in the distance between the different front edges and the rotating axis R may vary, depending on the desired cross sectional shape of the trench. The difference is preferably at least 0,05 metre. However, it will be understood that the dimensions of the excavating bucket according to the invention may be chosen dependent on the desired shape of the trench. The length of the intermediate edges 131, 132 may be chosen such that the different levels in the trench are at the desired relative depths in the soil 20 as desired.

Fig. 5 depicts an excavating bucket 150 according to an alternative embodiment of the invention. The edge defining the opening of the interior space of the excavating bucket 150, is provided with round corners, in stead of sharp corners. So, instead of sharp corners between connected edges, such as front edge 121 and intermediate edge 131, rounded corners are provided, as shown in Fig. 5. Such an excavating bucket 150 forms a trench having round corners, that reduces the collapsing of the side walls 204, 231, 232, 205 formed in the soil 20.

The portions 111, 112, 113 of the main plate as depicted in Fig. 3 are formed as bended plates that extend from the back edge 103 to their respective front edges 121, 122, 123. However, each of these portions 111, 112, 113 of the main plate may also be formed by two or more plate parts that are positioned with respect to each other under an angle. These plate parts of such a portion may be flat or bended.

The method of digging a trench 200 using an excavating bucket 100, 150 according to the invention could be performed in a single digging action (one dig) but may also be performed in two or more digging actions . As already stated above, the front edges 121, 122, 123 do not necessarily need to be straight edges as shown in the figures, but may also be provided with a structure, such as teeth or the like. The structure may be provided to make the movement of the front edge in the soil relatively smooth.

For the purpose of teaching the invention, preferred embodiments of the method and devices of the invention are described above. It will be apparent for the person skilled in the art that other alternative and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the true spirit of the invention, the scope of the invention being only limited by the annexed claims .

Claims

1. Excavating bucket (100, 150) comprising a main plate and a connector (102), the connector being arranged to connect the excavating bucket to an excavator (10) , the excavating bucket (100, 150) being arranged for performing a digging movement, the digging movement comprising a rotational movement about a rotational axis (R) , characterized in that the main plate is formed by at least a first and a second portion (111, 112) having a first and second front edge (121, 122), where a first distance between the first edge (121) to the rotational axis (R) substantially differs from a second distance of the second edge (122) to the rotational axis (R) .

2. Excavating bucket (100, 150) according to claim 1, in which the rotational axis (R) runs through the connector (102) .

3. Excavating bucket (100, 150) according to any one of the preceding claims, in which the first and second portion (111,

112) of the main plate have different curvatures.

4. Excavating bucket (100, 150) according to any one of the preceding claims, in which the first distance of the first edge (111) to the rotational axis (R) and the second distance of the second edge (112) to the rotational axis (R) differs with at least 0,05 metre.

5. Excavating bucket (100, 150) according to any one of the preceding claims, in which the excavating bucket (110, 150) further comprises a third portion (113) having a third front edge (123) , where the distance between the third front edge (123) to the rotational axis (R) substantially differs from the distance between at least the first or second edge (121, 122) to the rotational axis (R) .

6. Excavating bucket (100, 150) according to any one of the preceding claims, in which the excavating bucket comprises at least one intermediate plate (114, 115) having an intermediate edges (131, 132) being provided in between the first, second portion (111, 112) .

7. Excavating bucket (100, 150) according to claim 6, in which at least one connection between a front edge (121, 122, 123) and an intermediate edge (131, 132) is provided by a rounded corner.

8. Method for digging a layered trench (200) using an excavating bucket (100, 150) according to any one of the preceding claims.