WO1990010372A1

WO1990010372A1 - Improvements in or relating to tools

Info

Publication number: WO1990010372A1
Application number: PCT/GB1990/000355
Authority: WO
Inventors: Edward Fullerton
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-03-11
Filing date: 1990-03-08
Publication date: 1990-09-20
Anticipated expiration: 1991-09-11
Also published as: GB2228852A; AU5267490A; GB8905620D0

Abstract

The invention relates to a tool for taking an earth core. The tool generally comprises a tubular member (11) intended to be driven into the ground, with a restricted bore region (d3) adjacent the leading end (12) of the tool, intended to compact the core to a diameter less than the internal diameter of the greater part of the member (11) thus to facilitate removal of the core, and an enlarged external diameter (d4) at or adjacent the leading end (12), and greater than the external diameter (d1) of the greater part of the length of the member (11) to facilitate withdrawal of the member (11) from the ground.

Description

"IMPROVEMENTS IN OR RELATING TO TOOLS"

This invention relates to tools and, more particularly, to a tool for taking a core of earth.

It is well known in the art to take a core of earth, to form a hole for a fencing post or to remove a weed and its roots from a lawn, by driving a tubular element into the earth, whereupon a core of earth is entered into the bore of the tubular element, and then removing the element with the core of earth retained within the bore of the element.

Such tools are described in, by way of examples, British Patents No. 270,155, No.270,205, No.337, 97, No.360, 05, and British Patent Applications No.8217844, (Publication No. 2,122,462A) and No. 8620986 (Publication No. 2,197,572A) and the U.S.A. Patents No.3,534,994, No. 3,847,227, and 3927720.

A problem with all such prior art devices is that the tubular element is generally cylindrical in form with a bore of uniform cross-section and frequently the lower regions of the earth core will fall from, or be sucked from, the lower regions of the tubular element as the element is being withdrawn.

This problem is identified in British Patent No. 360,505, for example,and the solution proposed in that patent is to define a tapered restriction in the bore at the lower regions of the tubular element, said restriction causes the core to be compacted, and the restriction defines an internal shoulder to hold and grip the compacted core at its lower regions to prevent the core from falling out of the tubular element.

A further serious disadvantage experienced with all the prior art devices, including the devices disclosed in the above Patent specification No. 360505, arises when the tubular element is being withdrawn, when the surrounding earth grips the tubular element resisting withdrawal, and this problem is aggravated when the earth is moist or comprises or includes clay. Further, when the earth grips the tubular element at withdrawal the earth can be pulled up when the tool is withdrawn leaving an untidy irregular hole.

The present invention seeks to provide a tool for removing a core of earth which does not suffer from the above identified problems when the tool is withdrawn.

According to the present invention there is provided a tool, for taking a core of earth, comprising a hollow rigid member open at one end defining the leading end for entry into the earth, characterised by a region of enlarged cross-, section adjacent said leading end and concentric with the axis of said member.

In one embodiment in accordance with the invention the enlarged cross-section is defined by a ring element mounted on the tubular element.

In another embodiment the wall, or walls of the member are sloped outwardly towards the leading end of the member.

In a third embodiment the wall or walls defining said member are displaced outwardly over a region of said member adjacent to, but spaced from, said leading end.

It will now be seen that with the tool proposed by the present invention the region of enlarged cross-section forms a hole of larger cross-sectional area than the cross-sectional area over the greater part of the length of the member and whereupon the frictional resistance to withdrawal of the tool is restricted to that resistance between the enlarged cross- section and sides of the hole formed by said enlarged cross- section.

Preferably the said member includes a bore region of reduced internal cross-sectional area, adjacent to but spaced from said leading edge.

In one embodiment the region of reduced internal cross- section is defined by an element secured within the bore of said member and said element is most preferably of closed ring¬ like configuration, whereupon the reduced ^' internal cross- section is concentric with the axis of the member.

In another embodiment the said region of reduced internal cross-section is obtained by deforming a region of the wall or walls defining said member inwardly to define ^'said reduced cross-sectional area.

Preferably the said member is of tubular form, open at both ends, and the cross-sectional areas of its bore regions are concentric with the central axis of the member.

Preferably a second member extends from that end of the first member remote from the leading end thereof, concentric with the axis of said first member, and said second member has an internal diameter greater than the internal diameter of the regions of the first member iimiediately adjacent thereto.

In one embodiment in accordance with the invention the said second member has an aperture formed in one side thereof whilst in another embodiment the said second member defines two diametrically opposite apertures.

Preferably the axial length of the, or each, aperture is equal to or greater than the axial length of said first element and the width of the, or each, aperture is equal to or greater than the diameter of the bore of the first member immediately adjacent to said second member.

The aperture, or apertures, in the second member facilitate removal of a core pushed into the second member from the first member. - k -

In one preferred embodiment in accordance with the invention the said second member is formed integral with said first member but in an alternative embodiment said first and second members may be formed independently and provided with means for interlocking them into substantially rigid association.

Preferably the tool includes a handle arrangement, in rigid association with the first and second members, and most preferably the axis of said handle arrangement is substantially parallel with the axes of said first and second members.

In one embodiment in accordance with the invention the axis of said handle arrangement is substantially concentric with the axis of said first and second members and includes a stirrup-like opening engageable by the foot of the user to drive the first member into the earth.

In another embodiment the axis of the handle arrangement is off-set from the axis of the first and second members and the upper regions of the second member define a step or foot support to assist the user in driving the first member into the earth.

In one preferred embodiment according to the invention the second member comprises two generally parallel elements extending between said first member and said handle arrangement.

The invention will now be described further by way of example with reference to the accompanying drawings in which;

Fig.^'l. shows, in longitudinal cross section, one embodiment for the leading end region for a tool in accordance with the invention.

Fig. 2. shows, in longitudinal cross section, a second embodiment for the leading end region of a tool in accordance with the invention. Fig. 3 shows, longitudinal in cross section, a third embodiment for the leading end region of a tool in accordance with the invention.

Fig. 4 shows, in front view, one general construction for a tool in accordance with the invention.

Fig. 5 shows a side view of the embodiment illustrated in Fig. 4.

Fig. 6 shows a front view of a second construction for a tool in accordance with the invention,

Fig. 7 shows a side view of the embodiment illustrated in Fig. 6 and

Fig. 8 shows a cross section through the embodiment illustrated in Figs. 6 and 7 on the line II II. in Fig.7.

In the embodiment illustrated in Fig. 1 a hollow tubular member 11 has an external diameter dl and an internal diameter d2 for the greater part of its length and presents a leading end 12 intended to be driven into the ground to remove a core sample. A ring 13 is secured externally on member 11 adjacent to the leading end 12 and the outer cylindrical face of the ring 13 slopes upwardly and inwardly from a diameter d4 at said leading end 12 to the diameter dl of the tubular member 11.

A second ring 14 is secured in the lower regions of the bore d2 of member 11 and the bore of- the ring 14 tapers from a small diameter d3, remote from the leading end 12, to a bore diameter at the leading end 12, and which bore diameter is substantially equal to the bore diameter d2 of the member 11.

When the member 11 is driven into the earth, leading end 12 first, a core of earth is forced up the bore in ring 14 being compacted from the bore diameter d2 at the leading end 12 to diameter d3 by the ring 14 and thus above the ring 14 the core has a diameter less than the diameter d2 of the member 11. Further, as the member 11 is driven into the earth, the outer diameter d4 of the ring 13 makes a hole substantially equal to the external diameter d4 of the ring 13.

When the member 11 has been driven to its intended depth and withdrawal is initiated the external diameter of the member 11, being smaller than the external diameter of the ring 13, is not held by the soil defining the hole, the only resistance to upward displacement is that effected by the soil engagement with the ring 13 and the inclined outer face of ring 13 facilitates the withdrawal. Further, as withdrawal is initiated, some part of the core may fall from the volume defined between diameters d2 and d3 of the ring 14 but above diameter d3 the core is held by the shoulders I4a_ defined by the upper radial face of the ring 14.

Thus, by this means, an effective soil core is removed by the device and, on withdrawal of the device, the resistance to withdrawal is substantially restricted to the soil engaged with the outer sloping face of the ring 13.

In the embodiment illustrated in Fig. 2 a hollow tubular member 21, with an external diameter dl and an internal diameter d2 for the greater part of its length, presents a leading end 22. The side walls of the member 21 are deformed in the region of said leading end 22 to slope inwardly from a bore substantially equal to the bore d2 at said leading end 22 to a bore diameter d3, smaller than diameter d2. Spaced from said leading end 22 the said side walls are deflected outwardly to define an internal diameter greater than diameter d2 and then return to diameter d2, thereby to define an external diameter d4 which is larger than the external diameter of dl of the member 21.

It will be seen that, when the member 21 is driven into the earth, soil passing into the member 21 through the open bore in the leading end 22 is compressed to the diameter d3,which is smaller than the diameter d2, so that there is little frictional engagement between the core and the bore d2. Further, as the member 21 is withdrawn, the compressed slug in the member 21 above diameter d3 cannot pass downwardly through the bore of diameter d3 and is thereby retained in the member 21.

As the member 21 is driven into the ground, edge 22 leading, the hole formed by the maximum diameter d4 of the leading end 22 region has a diameter greater than the diameter dl whereupon, when the member 21 is being withdrawn from the hole, the resistance of the earth to withdrawal is substantially limited to the engagement of said soil with the enlarged diameter d4.

In the embodiment illustrated in Fig. 3 a tubular member 31, with an external diameter dl and an internal diameter d2 for the greater part of its length, has its side walls deformed adjacent the leading end 32 in such manner that said side walls slope inwardly from the leading end 22, where the external diameter of the member 31 is defined by diameter d4 which is larger than diameter dl, to a restricted internal diameter d3 and from this internal diameter d3 the side walls deflect outwardly to define the internal diameter d2 and external diameter dl.

Thus, when the member 31 is entered into the earth the leading end 32 of diameter d4 forms a hole of greater diameter than the diameter dl and soil entering the member 31 is compressed to the bore diameter d3 to define a compressed and retained core within the diameter d2. As with the embodiment of Figs. 1 and 2 the resistance to withdrawal is limited to the frictional resistance of that part of member 31 of diameter d4 with the surrounding earth.

In the general construction illustrated in Figs. 4 and 5 a first member 41, which may have a leading end region of any one of the forms illustrated in Figs. 1, 2 or 3, has a second member 42 formed integral therewith, on that end of member 41 remote from the leading end of the member 41.

The axis of the member 42 is substantially concentric with the axis of the member 41 and member 42 has a an internal bore d5 larger than the internal bore d2 of member 41, and an axial length greater than that of the member 41. The member 42 has an aperture 42a_^ in one side thereof and said aperture 42a having an axial length greater than the axial length of the member 41 and a width, between its defining side walls, greater than the diameter d2 of the member 41.

The member 42 is rigidly attached to a handle 43 by a bracket 44, which retains the axis of handle 43 is parallel to, but spaced from, the axes of members 41 and 42. A footplate 45 is secured on the top of member 42 (as viewed in Figs. 4 and 5).

In use the leading end of the member 41 is located to remove the desired core and, using the handle 43 as a guide, the user can press with one foot on the foot plate 45 to drive the element 41 into the ground, whereupon a core is forced into the member 41. When the desired depth has been reached, and which may be defined by the lower regions of the second member 42 touching the ground surface, the tool can be withdrawn, by- the handle 43, with minimum resistance because of the diameter d4 formed on the member 41 as described hereinbefore.

On the first withdrawal of the tool the core of earth extracted is wit-hin the member 41. The user will then find a second location for removing a core and, by repeating the operation ^'defined hereinbefore, a second core is forced into the first member 41, said second core pushes the first core upwardly into the member 42 and the first core can then be removed through the aperture 42a_.

When the last core has been cut the tool can be simply inverted and the core in member 41, having a diameter less than diameter d2, will fall readily down the member 41 into the member 42 for removal through the aperture 42a_.

In the embodiment illustrated in Figs. 6, 7 and 8^' a tubular member 51, which may have a leading end region substantially identical to any one of the forms illustrated in Figs. 1, 2 or 3, has a radial flange 52 formed on that end remote from the leading end of the member 51 and the flange 52 is engaged by two elements 53 and 54.

The element 53 comprises a lower part 53a^ intended to lie substantially parallel with the axis of the tubular member 51 and of arcuate cross-section, the inner curvature of which is based on a diameter d5 greater than the diameter d2 of the member 51.

From the upper regions of the section 53a. the member 53 is deflected outwardly to form a substantially horizontal section 53b_ (as viewed in Fig. 6) and therefrom is deflected upwardly to define a section 3£ the upper regions of which are bent inwardly and then upwardly to define a section 53d of arcuate cross-section, substantially parallel with the axis of the section 53a^ The sections 53b and 53c may be of rectangular cross-section.

At its lower regions the section 3a_^ has two slots, parallel with the axis of the tool, defining three limbs 53e_, 53f and an inner limb 53g. The lower regions of the limbs 53e and 53f are turned inwardly, with respect to the axis of the tool, to engage beneath the radial flange 52 of the member 51 and the limb 53g has a shorter length than the limbs 53e_ and 53f and is deflected inwardly, with respect to the axis of the tool, to engage the top surface of the radial flange 52 on the member 51. Thus, the flange 52 is trapped between the limbs 53_e, 53f and the limb 53a_.

The element 54 is a mirror image of the element 53 about the axis of the tool and no further description is required thereof.

The sections 53d of the elements 53 and 54 receive the lower regions of a handle 55 therebetween and said sections 53d are secured on either side of the handle by a bolt 56 passing therethrough

A second bolt 57 passes through the upper regions of the \ C sections 53ci of elements 53 and 54 and through a spacer sleeve 58 between the sections 53a_ of elements 53 and 54.

It will be seen that with the above embodiment the flange

52 is firmly clamped between the elements 53 and 54, the inwardly turned ends of the limbs 53e and 53f engaging beneath the radial flange 52 whilst the limbs 3g engage the upper surface of the flange 52, and the sections 53a_ of elements 53 and 54 are tensioned towards one another by the bolt 57, limited by the spacer sleeve 58.

To remove a member 51 from the tool it is only necessary to slacken off the bolt 57, urge the sections 53a of sections

53 and 54 apart to release the flange 52, and the member 51 will simply drop away. To fit a member 51 to the tool it is only necessary to locate the flange 52 between elements 53 and

54 and tension the bolt 57 to locate the inwardly turned lower ends of limbs 53e and 53f below the flange 52 with the limb 53g engaging the upper surface of said flange 52.

The embodiment illustrated in Figs. 6, 7 and 8 works in identical manner to the embodiment described with respect to Figs. 4 and 5, with the exception that to press the tool into the ground the user can insert one foot into the stirrup-like support defined by the elements 53 and 54 to assist in driving the member 51 into the earth. When the second core is being cut the first core will be forced upwardly between the sections 53a_^ of members 53 and 54 and readily removed through one or the other of the gaps between the members 53 and 54.

Claims

1. A tool, for taking a core of earth, comprising a hollow rigid member open at one end defining the leading end for entry into the earth and , characterised by a region of enlarged cross-section adjacent said leading end and concentric with the axis of said member.

2. A tool, according to claim 1 characterised in that said member comprises a hollow element and a ring element, said ring element being secured on the hollow element and defining said region of enlarged cross-section.

3. A tool according to claim 1, characterised in that the wall or walls of said member adjacent said leading end are sloped outwardly towards and to said leading end to define said region of enlarged cross-section.

4. A tool according to claim 1, characterised in that the wall or walls of said member are displaced outwardly over a region of said member adjacent to but spaced from said leading end to define said region of enlarged cross-section.

5. A tool according to claim 1, 2, 3 or 4 characterised in that said member includes a bore region of reduced internal cross-sectional area adjacent to but spaced from said leading end.

6. A tool according to claim 5 characterised in that said region of reduced internal cross-sectional area is defined by an element secured within the bore of said member.

7. A tool according to claim 6 characterised in that said internal element is of closed ring-like configuration and the said reduced internal cross-section is concentric with the axis of said member.

8. A tool as claimed in claim 5 characterised by a region of the member wall or walls deformed inwardly to define said bore region of reduced cross-sectional area.

9. A tool according to any preceding claim characterised in that said member is of annular form and the cross-sectional areas of all its bore regions are concentric with the central axis of said member.

10. A tool according to any of the preceding claims characterised in that a second member extends from that end of the first member remote from the leading end^' thereof and concentric with the axis of said first member, said second member having a larger internal diameter that the internal diameter of the regions of the first member adjacent thereto.

11. A tool according to claim 10, characterised in that the second member has an aperture formed in one side thereof.

12. A tool according to claim 11, characterised in that the axial length of the said aperture is equal to, or greater than, the axial length of said first element and the width of the aperture is equal to, or greater than, the diameter of the bore of the first member immediately adjacent to said second member.

13. A tool according to claim 10, 11, or 12 characterised in that said second member is formed integral with said first member.

14. A tool according to claim 10, 11, or 12 characterised in that said first member presents an outwardly directed radial flange at that end remote from the leading end thereof and said second member presents means engaged with said flange for retaining said first and second members in engaged relationship.

15. A tool according to any preceding claim characterised by a handle arrangement in rigid association with said first member and the axis of said handle arrangement is substantially parallel with the axis of said first member.

16. A tool according to claim 16, characterised in that the axis of the handle arrangement is off-set from the axis of the hollow rigid member.

17. A tool as claimed in claim 15 or 16 characterised in that said second member comprises two generally parallel elements extending between said first member and said handle arrangement.