Ground anchor

Abstract

A ground anchor 2 to which a moveable object can be tethered, the ground anchor comprising a ground engaging structure 4 arranged to be secured to the ground and a securing loop portion 6 mounted to t

Description

BACKGROUND The present specification relates to improvements in and relating to ground anchors, which are security devices that fix to the ground and provide a permanent fixing to which security chains / locks for securing any otherwise moveable object that may be vulnerable to theft are fastened in use. Bicycles and motor bikes, particularly, are prime targets for theft for the fact that they are readily portable and are high value items. The cyclist or motor cyclist, for example, has the choice of a range of different forms of security chain for tying down / securely tethering their motor vehicle. In general, however, there is little in the way of provision of suitable means for anchoring the security chains in a secure and space efficient manner. Ground anchors are utilised in some circumstances and can be installed in locations where space is at a premium. They are unobtrusive meaning the area in which they are located can still be used for other purposes, as an example in a location where vehicular access can sometimes be required. They typically comprise a ground engaging structure which is permanently fixed to the ground and from this extends a closed loop through which a tether such as a security chain can be passed. A problem exists with known ground anchors in that whilst they provide a closed loop to which a moveable item can be tethered, the closed loop is inherently relatively weak to attack as is exposed to attack as must extend upwards to allow for a tether to pass through the closed loop and is typically fabricated of mild steel. Often such ground anchors are fixed in locations which are relatively secluded such as inside a garage or shed, and as such there are a significant number of attacks using an angle grinder which cuts straight through the mild steel loop. It is a general object of the present invention to provide a secure ground anchor to which a moveable item can be tethered that is capable of withstanding significant attack, for example by an angle grinder. SUMMARY Aspects of the present disclosure are set out in the accompanying independent and dependent claims. Combinations of features from the dependent claims may be combined with features of the independent claims as appropriate and not merely as explicitly set out in the claims. According to an aspect of the present disclosure, there is provided a ground anchor to which a moveable object can be tethered, the ground anchor comprising a ground engaging structure arranged to be secured to the ground and a securing loop portion mounted to the ground engaging structure, the securing loop portion at least partially defining a loop for receipt of a tether, the securing loop portion comprising a body with a ceramic core. Although one suitable area of use of such anchors is in the prevention of theft of cycles and motorcycles, the ground anchors may be used in association with any moveable property that is vulnerable to theft. Other examples of use include tethering of industrial plant / construction industry plant and boats. Accordingly relative dimensions may be modified for the specific application. The securing loop of traditional ground anchors utilise either mild or stainless steel where the chemical composition can be selected to withstand significant attack, however it has been found that attack by an angle grinder or hacksaw for example readily cuts through the securing loop leaving a thief to readily remove the previously tethered moveable object. This is a particular issue for ground anchors where a securing loop portion is readily exposed and easy to access. The provision of a ceramic core has been found to be beneficial to attack from angle grinders, meaning even if this approach is taken by a thief, the moveable object can remain tethered. The ground anchor defines a closed loop through which a tether may be located thereby preventing the tether from being removed. The securing loop portion may partially or completely define the closed loop. If the securing loop portion only partially defines the closed loop, the ground engaging structure may define the remaining portion of the closed loop. The tether may take various forms such as for example a chain or the ‘D’ portion of a D lock typically used to secure bicycles. The securing loop portion may extend lengthwise between a first and a second end, and the ceramic core may extend the majority of the distance between the first and second ends. The ceramic core may be wholly encapsulated within the body. The body is a different material to the ceramic core. The body of the securing loop portion may comprise a metal material. The metal may comprise stainless steel. Whilst stainless steel provides reasonable resistance to attack, it is further able to with stand corrosive environments where mild steel would otherwise rust or would require carefully applied coating material which is likely to become worn away over time. The ground anchor may further comprise a fixing for fixing the ground engaging structure to the ground. The fixing is beneficially arranged to provide a permanent securing of the ground engaging structure to the ground. The fixing beneficially extends through the ground engaging structure. The ground engaging structure may comprise a through hole arranged to allow passage of the fixing, where a shoulder is provided in the ground engaging structure to engage with a head of the fixing and thereby retain the fixing therein. A cap may be provided for insertion into the through hole such that when installed access to the head of the fixing is prevented. The body of the securing loop portion may be pivotally mounted to the ground engaging structure. The securing loop portion may pivot between an operative position where a loop is defined for receipt of a tether and an inoperative position where no loop is defined for receipt of a tether. The body may extend between first and a second mounting formations for mounting to first and second respective ground engaging structure locations. The ground engaging structure may comprise a base for engaging with the ground and a carrier for carrying the securing loop portion, wherein the base is arranged to hold captive the carrier when the base is secured to the ground, wherein the case and carrier are arranged to cooperate such that the carrier can rotate relative to the base. The securing loop portion may be arranged to pivotally mount to the carrier. The ceramic core may comprise ceramic metal oxide. The ceramic metal oxide may be ceramic aluminium oxide. A ceramic metal oxide may be produced by pressing a metal oxide into a mold and sintered at high temperature for a predetermined period of time. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of this disclosure will be described hereinafter, by way of example only, with reference to the accompanying drawings in which like reference signs relate to like elements and in which: Figure 1 shows a ground anchor to which a moveable / portable object can be tethered in perspective view with a partial cutaway section in Figure la and again in perspective view with a partial cut away section for ease of understanding in Figure lb according to an embodiment of this disclosure; Figure 2a and b are see-through schematic perspective representations of a securing loop portion according to an embodiment of this disclosure; Figure 3 is a schematic representation of a step in the production process for the securing loop portion according to an embodiment of this disclosure; DETAILED DESCRIPTION Embodiments of this disclosure are described in the following with reference to the accompanying drawings. Referring to Figure la and b there is shown a ground anchor 2 to which a moveable / portable object can be tethered. Figure la shows the ground anchor 2 in perspective view with a partial cutaway section. Figure lb shows the same ground anchor 2 again in perspective view with a partial cut away section for ease of understanding installed into the ground. Referring to both Figures la and b, the ground anchor 2 comprises a ground engaging arrangement 4 and a securing loop portion 6. The securing loop portion 6 is pivotally mounted to the ground engaging arrangement at opposing first and second pivot locations 8 either side of the ground engaging arrangement 2. The pivot locations are diametrically opposite one another. The ground anchor arrangement 2 defines a securing loop 10 defined in this illustrative embodiment by the combination of the securing loop portion 6 and the upper surface of the ground engaging arrangement 4. The securing loop 10 is presented by reference numeral 10. It will be appreciated however that in an alternative embodiment the securing loop portion 6 may define a complete securing loop 10 by itself. Also visible in the cutaway portion in Figure la is the core 12 of the securing loop portion 6. The core 12 comprises a ceramic material. It is encapsulated by a body 14 made of a stainless-steel material. Such a combination is advantageous as the stainless steel provides good corrosion resistance and resistance to hammer attack, while the ceramic core material provides excellent ability to withstand attack from powered cutters and hacksaws for example. Further referring to Figure lb, the ground engaging arrangement 4 is presented in more detail including a fixing for fixing the ground engaging structure to the ground 18 which will typically comprise concrete comprising a bolt 20 and an expander anchor sleeve 22 where tightening of the bolt 20 into the ground effects expansion of the expander anchor sleeve 22 thereby securing the fixing and thus the ground anchor as a whole to the ground. There may comprise a spacer 30 between the bolt head and the expander anchor sleeve 22 to enable greater insertion depth thereby increasing the force necessary to extract the fixing. A cap 24 is provided for preventing access to the fixing when installed which in Figure lb is shown in a position ready to locate into the ground engaging structure 4. The cap 24, once inserted, is fixed in position and cannot be removed. In the illustrative embodiment the ground engaging structure 4 comprises a base 26 for engaging with the ground 18 and which comprises a through hole through which the fixing locates. The head of the fixing seats into an aperture provided in the base 26 and abuts against a shoulder. The ground engaging structure further comprises a carrier 28 for carrying the securing loop portion 6, wherein the base 26 is arranged to hold captive the carrier 28 when the base is secured to the ground 18. The case and carrier are arranged to cooperate such that the carrier can rotate relative to the base 26, and the carrier 28 may be termed a bearing. This allows rotation of the carrier and thus the relative positioning of the securing loop portion 6 to align with a user to locate a tether through the securing loop 10. The securing loop portion is pivotally mounted to the ground engaging structure in the illustrative embodiment. Accordingly, the securing loop portion 6 may pivot between an operative position where a loop is defined for receipt of a tether and an inoperative position where no loop is defined for receipt of a tether. In the inoperative position the securing loop portion 6 folds down and abuts against an outer edge of the carrier 28 so that a generally planar upper surface of the ground anchor 2 is presented made up of an upper surface of the base, an upper surface of the carrier, and a side of the securing loop portion 6. This means the ground anchor is relative unobstructive in a non-operative position. Referring now to Figure 2 a-b there is a schematic representation in perspective view (but being able to see through) of the securing loop portion 6. The securing loop portion 6 extends lengthwise between opposing ends at which are provided the first and second pivot locations 8 defined by apertures. The pivot locations are also mounting locations into which a pin locates to enable pivoting between the ground engaging arrangement and the securing loop portion 6. The ceramic core 12 is shown extending lengthwise most of the distance between the opposing ends from adjacent the pivot locations 8. The ceramic core 12 may comprise ceramic metal oxide and may comprise ceramic aluminium oxide. Such a solid ceramic material can be formed by pressing aluminium oxide powder into the shape of the core then sintered in a furnace at high temperature (e.g. 1600°C) for sufficient time (e.g. 48 hours) so that the aluminium oxide turns into a ceramic product. As an example only, the ceramic core may have a Vickers Hardness of 1144.2HV1 (measured under testing standard GB / T 16534-2009) and fracture strength of 417MPa (measured under testing standard of GB / T 37246-2018). Such a core material has proved particularly resistant to attack from a rotating blade such as presented by an angle grinder. The methodology of production of the securing loop may be as follows and utilises methodology of the lost wax process of manufacture: Step 1: An aluminium mold of the securing loop portion is provided in opposing mold parts into which is supported a ceramic core by stainless steel support pins. The mold is closed. Step 2: Wax is injected into the mould Step 3: The wax is allowed to set, and the wax representation of the securing loop portion is left including the ceramic core together with the support pins. The wax representation of the securing loop portion is removed from the mold. Step 4: The wax representation of the securing loop is dipped into a ceramic slurry to cover the wax representation and is then heated to cure and harden the ceramic slurry to provide a hardened slurry encapsulating the wax representation of the securing loop portion. Step 5: The dried slurry coated wax representation is heated sufficient to melt out the wax leaving the ceramic core held in place by the support pins located in a cavity defined by the solidified ceramic slurry. Step 6: Molten stainless steel is injected into the cavity and allowed to cool to solidify. Step 7: The solid ceramic slurry is removed to leave the solid stainless steel securing loop with the encapsulated ceramic core with the support pins 40 remaining protruding from the securing loop. A representation of this stage of the processing methodology is present in Figure 3. Step 8: The support pins are cut to leave a support pin portion in situ and the cut surface flush against the surface of the surrounding surface of the securing loop. The manufactured securing loop can then be assembled with the other components to form 5 the ground anchor as described above. The aluminium mold is provided for moulding the wax representation of the securing loop. Aluminium is a relatively easy material from which to machine a mold, and due to the low melting point of the wax can be readily utilised to mold a wax representation of the securing 10 loop portion. Although particular embodiments of this disclosure have been described, it will be appreciated that many modifications / additions and / or substitutions may be made within the scope of the claims.

Claims

1. A ground anchor to which a moveable object can be tethered, the ground anchor comprising a ground engaging structure arranged to be secured to the ground and a securing loop portion mounted to the ground engaging structure, the securing loop portion at least partially defining a loop for receipt of a tether, the securing loop portion comprising a body with a ceramic core.

2. A ground anchor according to claim 1 wherein the securing loop portion extends lengthwise between a first and a second end, and the ceramic core extends the majority of the distance between the first and second ends.

3. A ground anchor according to any preceding claim wherein the ceramic core is wholly encapsulated within the body.

4. A ground anchor according to any preceding claim wherein the body of the securing loop portion comprises a metal.

5. A ground anchor according to claim 4 wherein the metal comprises stainless steel. Whilst stainless steel provides reasonable resistance to attack, it is further able to with stand corrosive environments where mild steel would otherwise rust or would require carefully applied coating material which is likely to become worn away over time.

6. A ground anchor according to any preceding claim further comprising a fixing for fixing the ground engaging structure to the ground.

7. A ground anchor according to any preceding claim wherein the body of the securing loop portion is pivotally mounted to the ground engaging structure.

8. A ground anchor according to claim 7 where the body extends between first and a second mounting formations for mounting to first and second respective ground engaging structure locations.

9. A ground anchor according to any preceding claim wherein the ground engaging structure comprises a base for engaging with the ground and a carrier for carrying the securing loop portion, wherein the base is arranged to hold captive the carrier when the base is secured to the ground, wherein the case and carrier are arranged to cooperate such that the 5 carrier can rotate relative to the base.

10. A ground anchor according to any preceding claim wherein the ceramic core comprises ceramic metal oxide.

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