AU605389B2

AU605389B2 - Ribbed earth anchor

Info

Publication number: AU605389B2
Application number: AU26910/88A
Authority: AU
Inventors: Robert Fredrick Deike
Original assignee: Foresight Industries Inc
Current assignee: Foresight Industries Inc
Priority date: 1983-06-22
Filing date: 1988-12-15
Publication date: 1991-01-10
Anticipated expiration: 2004-06-21
Also published as: AU2691088A

Description

COMMON W E ALTH OF A U S T RA L I A PATENTS ACT ]q52 COMPLETE SPECIFICATI C o 8 (Original) FOR OFFICE USE Class Int. Class Application ,umber: Lodged: Complete Specification Lodged: Accepted: Published: ,,Priority: This document contains the amendments made under Section 49 and is correct for Lprinting.

*o A -ted Art: *0 Name of Applicant: Address of Applicant: FORESIGHT INDUSTRIES INC.

C.^780 !e Di-ice e -sLt 2 11 1 r COLORADO 8 2 3 ,oo United States of America Robert Fredrick DEIKE DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Actual Inventor(s) Address for Service: Complete specification for the invention entitled: "RIBBED EARTH ANCHOR" The following statement is a full description, of this invention, including the best method of performing it known to us -1 To: THE COMMISSIONER OF PATENTS (a member of th firm DAVIES COLLISON for and on behalf of the Applicant).

Davies Collison, Melbourne and Canberra.

I i RIBBED EARTH ANCHOR This invention is concerned with an e" improvement in earth anchors of tubular configuration, which anchors are driven lengthwise into the ground to a desired depth at which a cable 5 then attached to the anchor is tensioned to tilt the anchor transversely of the driven hole.

An anchor of the aforementioned type is the subject of our prior Australian patent 503,913. One t feature of the anchor described in that patent is a t* 10 reduced diameter, but still tubular, leading driving end that defines an internal abutment shoulder for C seating the impact end of a driving and guide rod by which the anchor is driven lengthwise into the ground, It has been found that, in certain ground conditions, substantial effort is required to drive the blunt ended anchor into the ground, and, moreover, that the blunt end is liable to be either stopped or easily deflected by localized rocky conditions. Patent specification 503,913 does envisage the possibility of a closed end with a driving point but does not teach any detail :in the matter. It is an object of the i 1 i attestlti rcqJrt.o Note, Initial all alterations A 1 1 L 'fr K I J A AVIIkS COLLISON, MELBOURNE and CANBERRA,

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It 0@er a 00 *4 Sr o ta ar a present invention, in a first aspect, to at least in part alleviate the difficulty just discussed.

The invention accordingly provides an earth anchor which comprises an elongated rigid tubular member having a leading driving end with an internal abutment adapted to be impacted by a driving tool, an open trailing end with an out-turned lip on one side thereof, and anchor means for an external cable disposed intermediate said ends on t4eside of said member opposite said one side, wherein said leading driving end includes a transverse wall substantially closing off the tubular member and defining the internal abutment, and plural integral ribs projecting forwardly from said transverse wall and extending 15 radially from an axially disposed core _aswhich, they merge.

There are preferably four ribs so that the i i sVere.

leading driving end ahead of the a ewall exhibits a cross configuration in end elevation. Such an end is in some contexts, referred to as a star point.

This invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an earth anchor according to the present invention, shown suspended from a cable; Figures 2 and 3 are side and end elevations of the anchor shown in Figure 1; Figure 4 depicts the anchor being driven into the ground; and Figure 5 shows the embedded anchor after the cable is tensioned.

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.1 4 The earth anchor 10 illustrated in the drawings is a unitary metal alloy piece and includes a metal tubular member 12 (hereinafter tube 12) with a star point leading end 13, a transverse closure wall 14 providing an internal abutment 14a, and a tapered trailing end 15 having an out turned lip 16 at one side of the tube. The tube 12 is cut or ground off from a level 17 along an arcuate path (which may if more convenient be substantially a flat plane) to the rounded tip 18 of the lip 16.

On the other side of tube 12, opposite the side at which tip 16 is disposed and intermediate its two ends, tube 12 is provided with an integral anchor means 20 comprising a bulky strap to which is attached *15 an external cable 11. Anchor means 20 is located so I that its eye 21 is rearwardly of the transverse centre of the mass of tube 12. In this way, when the anchor is freely suspended from the cable, its leading end 12 I e\ will tilt downwardly at an angle to the horizontal 20 between 200 and 500. Since the tapered trailing end :15 has le:s metal along its length than the leading end 13, eye 21 may be positioned about midway between the extremity 13a of the leading end 13 and the tip 18 o of the lip 16, and still leave most of the mass of the 25 anchor forewardly of the eye so that the freely suspended anchor will tilt with its leading end downwardly.

Anchor strap 20 is a solid integral portion of the anchor. It is however, aligned in a longitudinal direction so that eye 21 opens transversely of an axial plane of tube 12, and fashioned so that the 0 an n nn i li-- 444 4 #9.4 o 44 9.

4 4 44 44 4 r 4 *r 4 .4 4 4 4r 4r 4 44 major part of the volume of the eye is disposed Jhead of centre of the eye 21 through which the cable passes.

Anchor 10 may vary greatly in diameter, length and thickness depending upon the load it is to carry and the soil conditions of the ground in which it is to be driven. Typical anchor lengths are between and 50cm and typical anchor diameters between .6 and The wall thickness may vary from 1.5 to 6mnt.

10 However, as indicated, the tip 18 of lip 16 is, in accordance with an aspect of the invention, displaced from the adjacent external surface of tube 12 by a distance D materially less than 5% of the overall length L of tube 12 between the extremity 13a of the 15 leading end and the tip 18 of lip 16.

Leading end 13 is a star point of cross configuration when seen in end elevation. This is achieved by integrally forming four ribs 24 to project forwardly of closure wall 14 and to extend radially of 20 an axially disposed core 26 in which they merge. Ribs 24 are also integral with closure wall 14. It will be observed that the ribs 24 are between about 15% and about 30%, preferably in the region of 20-25%, of the overall length L of the anchor.

25 In and with reference to Figure 4, tube 12 slidably receives a driving and guide rod 22 with a rounded leading end 23 adapted to impact against the internal abutment shoulder 14a. Anchor 10 is driven into the ground 30 by a driver (not shown) acting on the top of the 22, forming an elongate hole 34 in the )rj;

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6 ground up which the cable 11 extends to a level above the ground.

Rod 22 holds anchor 10 in an upright position parallel with hole 34 and prevents the anchor from tilting or wandering out of parallel alignment with the hole that is being formed. Such trueness of direction and alignment has been found to be further enhanced by the star point configuration of leading end 13. Rod 22 may be pressed or repeatedly impacted against shoulder 14a without being withdrawn from tube t 12 to ensure maintenance of the anchor in its desired upright position until it has reached the desired depth.

t I After anchor 10 has reached the desired depth in *t 15 ground 30, driving rod 22 is retracted from hole 34 and cable 11 pulled in the direction of the arrow 36.

The resultant tension in the cable causes lip 16 to plough into the ground alongside hole 34 to form a ~fulcrum 38 for the anchor about which leading end 13 is pulled upwardly into the ground on the opposite .tc t side of hole 34 whereupon the anchor 10 assumes an inclined position transversely of the hole (Figure This tilting or rotation of the anchor leaves a V 4C: somewhat enlarged cavity 40 at the base of hole 34 below the anchor but leading end 13 and trailing end 16 of the anchor are firmly embeded in the ground laterally of the hole 34 and the cavity As the anchor travels downwardly through the ground during the driving stage, the bulkier forward portion of anchoring strap 30 provides protection for the following cable 11 and helps prevent or minimise 7 severe abrasive or cutting contact against sharp edges or rough surfaces against which the anchor might pass as it descends.

During the embeding stage, it is found that the reduced degree of out turning of lip 16, in comparison to prior anchors, substantially reduces the frequency of occasions in which the lip 16 ploughs too far into the ground, causing the anchor to tip too far tie other way, and thereby reducing the potential holding load on the cable 11.

It should be understood that the term "cable" is CteC used herein includes chains, wires, rods, ropes and r r- the like as well as conventional cables.

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Claims

1. An earth anchor which comprises an elongated rigid tubular member having a leading driving end with an internal abutment adapted to be impacted by a driving tool, an open trailing end with an out-turned lip on one side thereof, and anchor means for an external cable disposed intermediate said ends ont4he side of said member opposite said one side, wherein said leading driving end includes a transverse wall substantially closing off the tubular member and defining the internal abutment, and plural integral ribs projecting forwardly from said transverse wall and extending radially from an axially disposed core into which they merge. a

2. An earth anchor according to claim 1, wherein there are four of said ribs so that the leading Sci\d k=-rov\erse driving end ahead of the =csu wall exhibits a cross configuration in end elevation.

3. An anchor according to claim 1 or 2 wherein the longitudinal extent of the ribs is between 15 and of the overall length of the anchor.

4. An anchor according to claim 3 wherein the longitudinal extent of the ribs is between 20 and of the overall length of the anchor,, L

5. An earth anchor according to any preceding claim wherein said anchor means defines an eye which is open transversely of an axial plane of the tubular member. IAi 9

6. An earth anchor according to claim 5 wherein said eye is shaped asymmetrically so that the major part of the volume of the anchor means lies ahead of the centre of the eye.

7. An anchor according to any preceding claim wherein the displacement of the tip of said lip with respect to the external face of said one side of the tubular member is materially less than 5% of the length of the anchor between said tip and the Sextremity of the driving end.

8. An anchor according to claim 7 wherein the Sdisplacement of the tip of said lip with respect to 11 the external face of said one side of the tubular Cc C Sr member is in the range 2 to 3% of the length of the anchor between said tip and the extremity of the driving end. C c

9. An earth anchor according to claim 1, ,c substantially as hereinbefore described with reference to the accompanying drawings. DATED this 13th day of December, 1988. FORESIGHT INDUSTRIES INC. By its Patent Attorneys DAVIES COLLISON