1. Field of the Invention
The present disclosure relates generally to ground anchors, and more particularly, ground anchors used to support solar collector arrangements.
2. Description of the Background Art
Photovoltaic arrays are used for a variety of purposes, including as a utility interactive power system, as a power supply for a remote or unmanned site, a cellular phone switch-site power supply, or a village power supply. These arrays can have a capacity from a few kilowatts to a hundred kilowatts or more, and are typically installed where there is a reasonably flat area with exposure to the sun for significant portions of the day.
In general terms, these solar collector assemblies have their solar collector modules, typically photovoltaic modules, supported on a frame. The frame is generally supported above the ground by vertical pier tubes. The vertical pier tubes are typically driven very deeply into the ground. The pier tubes may also be supported and stabilized by concrete footings.
One embodiment relates to an earth-penetrating apparatus. The apparatus includes a pole with a hollow portion therein and a bottom end which is configured to be driven into ground. Anchoring parts are configured to be radially extendable from the pole. In addition, an expansion mechanism is configured to apply a force to the anchoring parts so as to radially extend the anchoring parts from the pole after the pole has been driven into the ground.
Another embodiment relates to a solar collector arrangement. The arrangement includes a plurality of earth-penetrating anchors which are driven into ground. Each anchor includes (a) a pole with top and bottom ends, the pole having a hollow portion therein and a pointed tip at the bottom end which is configured to be driven into ground, (b) anchoring parts configured to be radially extendable from the pole, and (c) an expansion mechanism configured to apply a force to the anchoring parts so as to radially extend the anchoring parts from the pole after the pole has been driven into the ground. The arrangement further includes a support structure coupled to the plurality of earth-penetrating anchors. An array of solar panels is attached to the support structure.
Other embodiments, aspects and features are also disclosed.
In the present disclosure, numerous specific details are provided, such as examples of apparatus, process parameters, materials, process steps, and structures, to provide a thorough understanding of embodiments of the invention. Persons of ordinary skill in the art will recognize, however, that the invention can be practiced without one or more of the specific details. In other instances, well-known details are not shown or described to avoid obscuring aspects of the invention.
Anchoring parts 106 are configured to be radially extendable from the pole. As shown, the anchoring parts may comprise curved metal tines that may be extendable through corresponding holes 107 near the bottom end of the pole. Multiple anchoring parts are preferably configured. An exemplary embodiment may have two or three such anchoring parts and corresponding holes.
An expansion mechanism is configured to apply a force to the anchoring parts so as to radially extend the anchoring parts from the pole after the pole has been driven into the ground. As shown, the expansion mechanism may comprise an inner rod 108 which is coupled via a plate (flange) 109 to a top portion of the anchoring parts.
A sequence of three illustrative diagrams is shown in
The second diagram (
The third diagram (
The actuating mechanism in
Anchoring parts 206 are configured to be radially extendable from the pole. As shown, the anchoring parts may comprise pieces of the pointed tip of the pole. In an exemplary embodiment, the pointed tip may be formed from three or more of the anchoring parts which may be coupled to the bottom of the pole using a hinge mechanism 207.
An expansion mechanism is configured to apply a force to the anchoring parts so as to radially extend the anchoring parts from the pole after the pole has been driven into the ground. As shown, the expansion mechanism may comprise an inner rod 208 which is inserted into the hollow portion of the pole and pushed down to the bottom of the pole. The rod may itself have a pointed tip 210 on its bottom end. When the tip of the rod passes through the tip of the pole, the anchoring parts rotate on their hinges so as to become extended in a radial manner from the pole.
A sequence of five illustrative diagrams is shown in
Similar to
Anchoring parts 406 are configured to be radially extendable from the pole. As shown, the anchoring parts may comprise metal prongs. In an exemplary embodiment, the metal prongs may be bent at both ends. In an initial configuration, a majority of each prong may be positioned within the hollow portion of the pole.
An expansion mechanism is configured to apply a force to the anchoring parts so as to radially extend the anchoring parts from the pole after the pole has been driven into the ground. As shown, the expansion mechanism may comprise, initially, one bent end of each prong which protrudes out of a corresponding opening 407 in the side of the pole.
A sequence of five illustrative diagrams is shown in
After the pole is driven into the ground to the desired depth, an upward force is applied to the anchoring parts 406, for example, by pulling upon the tension member 410 which is attached to the actuating device 408. This upward force is represented by the up arrow in the diagram. The upward force activates the expansion mechanism. Due to the upward movement of the anchoring parts inside the pole, the prongs extend outward radially from the pole. This happens because the holes in the side of the pole exert a downward and outward force on the protruding portion of each prong so as to effectively pull the prong out from within the pole. The fourth (
The sleeve has a bottom end which may comprise multiple prongs (segments) 504 that will later be deployed as anchoring parts. An expansion mechanism is configured to apply a force to the metal prongs so as to radially extend them from the sleeve after the sleeve has been driven into the ground 501. As shown, the expansion mechanism may comprise a bolt 508 with a larger bulbous portion 509 at a bottom end. A nut 503 may be attached to the top end of the sleeve. A top end of the bolt may be screwed through the nut such that the bulbous end of the bolt is near to the prongs at the bottom of the sleeve.
Two illustrative diagrams are shown in
In this example arrangement, the row has sixty panels or modules 14, i.e., thirty sets of two modules. There are four vertical pier tubes 16, which can be round or square cross section, as desired, each supported in the earth. Each pier tube 16 may comprise the outer tube (or pole or cylinder) of an embodiment of the earth-penetrating expansion anchor disclosed herein. Alternatively, each pier tube 16 may be firmly attached to an earth-penetrating expansion anchor.
At a top end of each pier tube 16 may be a pier cap weldment 20, which may have a transverse square tubular sleeve that fits the profile of the torsion tube 12. The pier caps 20 on the pier tubes 16 may be aligned so that the torsion tube 12 threads through them. There may be multiple support rails or panel rails 22 attached onto the torsion tube 12, and these rails 22 may be arranged across tube at right angles to the tube axis and may be spaced apart the width of one panel or module 14.
Conventional pier tubes for a typical solar array installation may be 18 feet or so in length with about 12 to 14 feet embedded into the earth (depending on conditions, such as the soil type). The cost of these long conventional pier tubes and the installation thereof is substantial. If concrete footings are used to support the pier tubes then additional labor and material costs are required.
In accordance with embodiments of the present invention, the radially extendable portions of the anchors reduces necessary lengths of the pier tubes embedded in the earth. Using the expansion anchors as disclosed herein reduces the necessary length of the pier tubes, such that, for example, only about 4 to 8 feet of length needs to be embedded in the earth, without the use of concrete footings. This reduces the overall length of the pier tubes to be 8 to 12 feet, and may lower material and installation costs.
Existing screw or helical type anchors include those made by Krinner GmbH of Strasskirchen, Germany and Terrafix GmbH of Eschenbach, Germany. However, neither of these products deploy or change state after they are inserted into the ground. Moreover, in some cases, costly dedicated machinery is required for installation of these anchors.
While specific embodiments of the present invention have been provided, it is to be understood that these embodiments are for illustration purposes and not limiting. Many additional embodiments will be apparent to persons of ordinary skill in the art reading this disclosure.