GB2128229A - Excavator - Google Patents

Abstract

An excavator comprises a hollow tubular member (1) which has, at its proximal region, an insertion member (3). The insertion member (3) has an inner edge (10) and an outer edge (12, 13), the outer edge having a region which tapers towards the inner edge (10). The junction of the inner edge (10) and the outer edge (12, 13) forms an insertion point (11). Inner and outer ledges (15, 14) are defined, the former being to support matter which has been compressed during insertion of the excavator into the ground, and the latter being to allow clearance between the outer face of the hollow member (1) and the outer edge (13) during insertion of the excavator. The excavator may be conveniently attached to existing hydraulically actuated positioning equipment, and is capable of forming holes of a given diameter quickly and efficiently. <IMAGE>

Description

SPECIFICATION An excavator The present invention relates to an excavator and, more particularly, to an excavatorfor use in forming holes of a given depth and cross-section.

Known equipmentforforming holes for posts and the like generally comprise an auger, which is provided with a stem having a threaded proximal region such that when the auger is pushed into the ground and rotated, the earth to be excavated is dispelled outwards as a result of the design ofthe thread.

It is difficult to control exactly the dimensions of holes formed by an auger, and, further, forming holes using an auger is time consuming.

According to one aspect ofthe present invention there is provided an excavator comprising a hollow tubular member having, at a region of the tubular member intended for insertion into matterwhich isto be excavated, an insertion member,wherein the insertion member is of a cross-section which has an insertion point atthe junction of an inner edge and an outer edge, the outer edge having a region which tapers towards the inner edge, the distal end ofthe outeredge being spaced from an outerfaceofthe tubular member whereby an outer ledge is defined to allow clearance between the said outerface and the said matter when the excavator is being inserted into the matter, and the distal end of the inner edge being spaced from an innerface of the tubular member whereby an inner ledge is defined to support matter which has been compressed during insertion ofthe excavator and which has expanded laterally above the plane of the inner ledge.

Thetubular member may be of any suitable cross-section, according to the hole to be formed; however, an excavator in accordance with the present invention is particularly efficient ifthetubular member is of circular cross-section, although a square cross-section could be useful for making holes for square posts.

Preferablythe hollow member has an axis and the spacing from the axis ofthe inner edge at its distal end is less than the spacing of the inner edge at the insertion point Preferably the hollow member is provided with an open end, opposite the region of the hollow member having the insertion member, whereby when the hollow member containing the supported matter is inverted, such matter is permitted to fall out of the hollow member.

In a preferred embodimentofthe present inven tion,the outer ledge has a width which is less than that of the inner ledge, and the outer edge further has a substantially vertical distal region.

Conveniently the excavator is further provided with attachment means for attaching the excavatorto hydraulically actuated positioning equipment, and may comprise penetrating means for initially penetrating resistant matter before insertion ofthe excava tortherein.

According to another aspect of the present invention there is provided excavation apparatus comprising hydraulically actuated positioning equipmentto which is attached an excavator according to any preceding claim.

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, byway of example to the accompanying drawings in which: Figure 1 shows a vertical section through an excavator in accordance with an embodiment ofthe present invention; Figure 2 is a viewofthe excavatortaken along the line Il-Il in Figure 1 showing, in addition, its working relationship with conventional hydraulically actuated positioning equipment; Figure 3 is a view looking in the direction ofthe arrow ill in Figure 1; Figure 4 is a diagrammatic side view of the excavator and conventional hydraulically actuated position equipment with the excavator in an inverted position; and Figure 5 is a more detailed diagram of the insertion member shown in Figures 1 to 4.

As shown in Figures 1 and 3, the excavator comprises a hollow cylindrical tube 1, having a substantially constant circular cross-section along its length. The tube 1 may be constructed from steel tubing.

The tube 1 may be provided at its upper region with a penetrator 2, for use in penetrating hard ground beforethe lower, insertion region ofthetube 1 is inserted in the ground.

The lower, insertion region of the tube 1 is provided with an insertion member 3, to be described in more detail hereinafterwith reference to Figure 5, which ensures ease of entry into the ground, and the right amount of compression of the material to be excavated. The tube 1 is further provided, at its upper region, with side plates for use in attaching the excavator to conventional hydraulically actuated positioning equipment, generally designated by numeral 5 (Figure 2).

In Figure 2, reference numeral 6 designates a hydraulic ram used to control movement ofthe excavator, and the tube 1 is shown inserted into the ground to a greater depth than is indicated in Figure 1.

The insertion member3 is shown in detail in Figure 5. This member3 may be manufactured separately and welded to the lower region of the tube 1. The particular member3 illustrated comprises several important characteristics which will now be described.

The inner edge 10 ofthe member3 is such as to cause some compression ofthe matterto be excavated, for example soil, as the tip 11 ofthe member 3 is inserted into the ground. Thus the inner edge 10 has a length, a, which is such as to achieve the optimum amount of compression ofthesoil or other matter according to the characteristics of such matter. In addition, the inner edge 10 is usually slightlytapered towards the leading outer edge 12.

The leading outer edge 12 is of such a length, b, and inward taper, as to permit ease of entry ofthe cutting member 3 into the ground, the inward taper being adjusted byvaryingthe dimension c, of outeredge 13.

The outer edge 14 has a width, d, sufficientto allow clearance between the ground and the outerface of the tube 1 to ease penetration of the excavator into the ground, whilethe width, e, of the inner ledge 15 is such as to allow the soil or other matter compressed by inner edge lOto be supported after expansion, thereby preventing the soil from escaping from the lower region of the tube 1.

Typical values for dimensions atof(fdesignating the width ofthe wall ofthe tube 1 ) are given below, by way of example: a = 11/2" (3.81 cm) b = 1.114"(3.18 cm) C = 1/2" (1.27 cm) d = 1/8" (0.32 cm) e=7/16"(1.11cm) f= 114" (0.64cm) The operation ofthe excavator will now be described with reference to Figures 2 and 4. If required, the first step is to initially penetrate the ground with the penetrator 2. The excavator is then inverted underthe action of the hydraulic ram 6 and pushed into the ground (Figure 2). The soil is compressed into the tube 1 until the desired depth is reached, which may be indicated by marks on the outside of the tube 1, at which point the excavator is pulled out of the ground. The tube 1 now contains the material 7, which is to be excavated, supported in the tube bythe inner ledge 15 of the insertion member 3.

Next, thetube 1 is inverted (Figure 4) to allow the matterto escape from the tube 1 when the end ofthe tube 1 is struck, thereby causing vibration of the tube sufficient to dislodge the matter7.

The excavator is constructed as a simple attachmentto known equipment in the medium size excavator industry, enabling post-hole excavation at a capacity and capability beyond other attachments on the market at present. No modifications are required to existing hydraulically actuated positioning equipment.

Claims (10)

1. An excavator comprising a hollowtubular member having, at a region of the tubular member intendedforinsertion into matterwhich isto be excavated, an insertion member, wherein theinsertion member is of a cross-section which has an insertion point atthejunction of an inner edge and an outer edge, the outer edge having a region which taperstowardsthe inner edge, the distal end ofthe outer edge being spaced from an outerface ofthe tubular member whereby an outer ledge is defined to allow clearance between the said outerface and the said matter when the excavator is being inserted into the matter, and the distal end ofthe inner edge being spaced from an inner face of the tubular member whereby an inner ledge is defined to support matter which has been compressed during insertion of the excavator and which has expanded laterally above the plane ofthe inner ledge.

2. An excavator as claimed in Claim 1, wherein the hollow member has an axis and the spacing from the axis of the inner edge at its distal end is less than the spacing ofthe inner edge atthe insertion point.

3. An excavator as claimed in Claim 1 or2, wherein the tubular member is of circular crosssection.

4. An excavator as claimed in Claim 1,2 or3, wherein the hollow member is provided with an open end, opposite the region ofthe hollow member having the insertion member, whereby when the hollow member containing the supported matter is inverted, such matter is permitted to fall out of the hollow member.

5. An excavator as claimed in any preceding claim, wherein the outer ledge has a width which is less than that of the inner ledge.

6. Aexcavator as claimed in any preceding claim wherein the outer edge further has a substantially vertical distal region.

7. A excavator as claimed in any preceding claim, which is provided with attachment means for attaching the excavator to hydraulically actuated positioning equipment.

8. An excavator as claimed in any preceding claim further comprising penetrating meansforinitially penetrating resistant matter before insertion of the excavator therein.

9. An excavator substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

10. Excavation apparatus comprising hydraulically actuated positioning equipment to which is attached an excavator according to any preceding claim.