GB2058869A

GB2058869A - Explosively Propelled Buried Ground-Marker Injected by an Earth-Anchor or Survey Beacon to Provide a Concealed Reference Point Below Ground Level

Info

Publication number: GB2058869A
Application number: GB7900648A
Authority: GB
Original assignee: Wise E G
Current assignee: Wise E G
Priority date: 1979-01-08
Filing date: 1979-01-08
Publication date: 1981-04-15
Also published as: GB2058869B

Abstract

A method of and apparatus for providing a concealed marker below the surface of the ground whose position is separate from but co-axial with, or otherwise spatially related to, an earth anchor or survey beacon extending into the ground mass from its surface level, comprises driving earth anchor, or beacon into the ground mass with the marker attached to but not secured to the anchor and then operating a mechanism of within the anchor to separate the marker from the anchor and to cause the further penetration of the marker into the ground mass along the penetrating axis of the anchor. The further penetration into the ground of the marker may be effected by either an explosive charge within the anchor or marker, or by a retractable rod operating mechanically in, or through, the anchoring mechanism. As an aid to its subsequent recovery from its concealed position the marker may be either magnetised or made radio-active prior to its installation into the ground. <IMAGE>

Description

SPECIFICATION Explosively Propelled Buried Ground-marker Injected by an Earth-anchor or Survey Beacon to Provide a Concealed Reference Point Below Ground Level This invention relates to improvements in a method of and apparatus for anchoring and is particularly concerned with providing a concealed anchor to form a reference point in earth or ground. Such reference points are commonly referred to as buried reference markers and are used to permanently establish the exact relative positions of a series of positions within an area of the earth to which the surface features within that area are accurately related by survey methods.

Any reference or survey marker or monument installed in the ground and intended to form a permanent station or beacon visible above ground level may, in time, be disturbed or removed either accidentally or by deliberate effort. When such markers or monuments are removed from an extensive surveyed area the accuate relationship of the recorded survey detail is no longer possible and expensive andlime-consuming field-work is necessary to re-establish the exact positions of legal boundaries, cultural features and the designed structures of engineering projects, relative to the original survey.

As a safe-guard against the accidental or wilful removal of an established survey monument or anchor or post driven into the ground a secondary or subsidiary buried marker attached to but not secured to the penetrating end of the shaft of the primary marker or monument is described in the Provisional Specification No. 12832 filed on 1 April, 1978 under the British Patents Acts 1949-1961.

It is an object of the present invention to provide an improved method of providing at the time of installing a survey marker or monument in the ground a second or subsidiary marker buried in the ground and separate from the visible said marker or monument and having a common longitudinal axis with the said visible monument the purpose of the second or subsidiary buried marker being to remain concealed within the earth in the event of the distruction or disappearance of the primary visible monument and which can thereafter be located and unearthed and its co-ordinated position, or position relative to other survey beacons or markers, re-established.

It is a further object of the present invention to provide an improved buried marker separate from its co-axial surface beacon or monument which shall be economic to manufacture, simple to install, robust and accurate in use and which will not be revealed to a person or persons wilfully and illegally removing its associated surface monument.

According to one aspect of the present invention there is provided a method of producing a concealed buried survey or boundary marker which comprises the steps of installing in the ground an earth anchor similar in operating principle and construction to the anchors described and illustrated in British Patent Specifications Nos 01471/77, 22037/77, 14514/78 and 37577/78, but having in the case of the present invention an earth penetrating head which is divided by a circumferential section into two parts namely a leading or penetrating end and a following end incorporating the means of deflecting deformable metal bars or piates to form anchoring flukes or other anchoring mechanisms, the said two ends of the earth penetrating head being provided with the means of connecting the two ends together and for connecting the assembled head to the anchor shaft such means including by way of example pinning or peaning or dimpling one or both ends of the head to the anchor shaft or by means of screw-threaded connecting coliars or bayonet-type connectors.

The leading or penetrating end of the anchor head incorporates a tube or barrel, extending from its leading end to a chamber formed in the head and in which an explosive cartridge can be inserted before the head is assembled as heretofore described the said tube or barrel being a sliding fit with the shaft of the buried marker which is coaxial with the anchor and which can be separated from the anchor head by the detonation of the explosive cartridge after the anchor has been installed in the ground and so concealed.With advantage the detonation of the explosive cartridge is by a firing-pin operable in the following end of the earth penetrating head of the anchor the said firing pin being caused to engage with the detonator of the explosive cartridge by the anchor dolly connecting the following ends of the deformable fluke bars when the said dolly has been driven almost to the forward end of its travel in order to deform the fluke bars into their extended operating positions.

According to another aspect of the present invention where the cross-section of the anchor shaft and the dolly is sufficient to permit the enlargement of the firing pin to form a ram-rod, the explosive cartridge and its chamber may be dispensed with and the enlarged pin or ram-md elongated to directly drive forward the buried marker from its barrel in the anchor head and thereby disengage the marker from the anchor.

An embodiment of the invention will now be described by way of exarnple, reference being made to the accompanying drawings in which: Fig. 1 is a sectional elevational view of an anchor and marker device according to the present invention.

Fig. 2 is a cross-sectional view on the line A-A' of Figm 1.

The anchoring and marker device illustrated in Figs 1 and 2 comprises the following end of the anchor head 1 incorporating the means 2 for deflecting deformable metal bars 10 outwardly to form anchoring flukes the said following end 1 being connected to the leading end 4 of the anchor penetrating head either by the screwthreaded collar 14 or by the dimple or dimples 13 or by similar mechanical connection means the assembled head being also secured to the anchor shaft 3 by dimples 12 or by similar mechanical connection means.The buried marker 6 occupies the tube or barrel in the penetrating end of the anchor head the said barrel extending to the explosive cartridge chamber containing the cartridge 5 which in the illustration is a standard twelve-bore shot-gun cartridge whose ball charge has been removed and replaced with cottonwaste or similar packing material to retain the explosive charge against the detonator. A firing pin 7 passes through a central hole 8 in the following end 1 of the anchor penetrating head and is prevented from engaging with the cartridge detonator during the installation of the anchor into the ground and the extension of the anchoring nluke bars by the spring 9.When the fluke bars 10 have been extended by the driving forward of the dolly 11 to almost its full length of travel within the anchor shaft 3 the leading face of the dolly 11 bears against the firing pin 7 and further forward movement of the dolly will thereafter actuate the firing pin and detonate the cartridge 5 thereby ejecting the marker 6 into the ground beyond the anchor head. Where the resistance to extraction from the earth of the anchor flukes is required to be increased by the addition of fluke supporting webs such webs may be secured either to the assembled penetrating anchor head or to the anchor shaft as illustrated at 15 in the accompanying Figs. 1 and 2.

It will be apparent that the shaft 6 of the buried marker may be extended beyond the penetrating end of the leading end 4 of the anchor head in order that the said marker shaft may if necessary be provided with spring-loaded or similar selfoperating flukes to secure its correct buried position in the ground as described and illustrated in British Patent Provisional Specification No.

12832 of 1 April 1978.

With advantage the buried marker may also be magnetised or otherwise incorporate a magnet to improve its sensitivity to detection by a minedetector or imilar electrical metal detecting device or alternatively the marker may incorporate a trace radio-active element detectable by a geiger-counter or similar radioactive locating device.

Claims

1. A method of producing a concealed buried ground marker within a ground or earth mass whose position within that ground mass is separate from, but spatially related or referenced to an earth anchor or shaft or survey beacon installed into the earth from above ground level and which comprises the steps of driving into the ground an earth anchor or shaft or survey beacon to whose penetrating part or end the said marker is attached but not secured so that during Installation into the ground the longitudinal axis of the marker and that of the anchor shaft or beacon remain linearlycoinci ent and the direction of penetration of the marker into the ground, ahead of the anchor, is accordingiy the same as that of the anchor shaft or beacon.

After the installation of the combined earth anchor or shaft or beacon and its attached marker into the ground the mechanism of the said anchor shaft or beacon is operated to separate the marker from the anchor and to cause the further penetration of the marker through the ground mass ahead of, but independent of the anchor but along the axis of penetration of both.

The separation of the marker from the anchor shaft or beacon and its concealment by its further penetration into the ground, independent of the anchor is effected by an explosive charge or cartridge contained in a chamber within the penetrating part of the anchor the said charge or cartridge being detonated after the installation of the anchor either from above the surface of the ground by a firing pin connecting to the detonator of the explosive charge or cartridge or by similar mechanical or electrical or chemical firing systems operable from above the surface of the ground or by a firing pin or similar mechanical means of detonation incorporated into the mechanism of the penetrating or leading part of the anchor.

2. A method according to Claim 1. in which the marker is engaged by and detached from the anchor after installation into the ground mass by means of a retractable bar or rod passing in or through the anchor mechanism and mechanically operated from above ground level and which after disengaging the marker from the penetrating end of the anchor will cause the further movement of the marker along the penetrating axis of the anchor and which will thereafter disengage from the marker and be withdrawn to or through the anchor mechanism.

3. A method of producing a concealed buried marker substantially as herein defined.

4. A device comprising an earth anchor or shaft or survey beacon having at, or near to, its earth penetrating or leading end a rigid marker attached to but not secured to the said penetrating end whose longitudinal axis is coincident with that of the anchor shaft or beacon and whose direction of penetration into the earth mass ahead of the anchor will accordingly be the same as that of the anchor shaft or beacon.

After the installation of the combined device into the ground the mechanism of the anchor is operated to separate the marker from the anchor and to cause its further penetration through the ground ahead of and independent of the installed anchor and along the axis of penetration of the anchor.

The setaration of the marker from the device and its concealment by further penetration of the earth mass is effected by an explosive charge or cartridge housed in a chamber within the the penetrating head of the anchor the said charge or cartridge being detonated after the installation of the device either from above ground level by a firing pin connecting to the detonator of the charge or cartridge or by similar mechanical or electrical or chemical firing means operable from above the surface of the ground or by a firing pin or similar mechanical means of initiating detonation incorporated into the mechanism of the penetrating or leading part of the anchor.

5. A device according to Claim 4. in which the marker is engaged by and detached from the anchor after installation into the ground mass by means of a retractable bar or rod passing through or in the anchor mechanism and mechanically operated from above ground level and which, after disengaging the marker from the penetrating end of the anchor will cause the further movement of the marker along the penetrating axis of the anchor and which will thereafter disengage from the marker and be withdrawn to or through the anchor mechanism.

6. A device for locating a concealed buried marker arranged constructed and adapted to operate substantially as herein described whose said marker may be either magnetised or rendered radio-active before installation into the ground as an aid to its subsequent re-discovery.