Electrical grounding strip

An electrical grounding strip has a first link and a second link, wherein the second link is connected directly to the first link, and each of the first and second links has a portion lying substantially in a plane and has at least one electrically conductive spike attached to the portion. The spike projects generally orthogonally to the plane of the link portion. An electrically conductive ground strap is in electrically conductive contact with the spikes of each of the first and second links.

FIELD OF THE INVENTION

The present invention relates generally to devices for electrical grounding and in particular to devices for electrical grounding for use with mobile electrical equipment.

BACKGROUND OF THE INVENTION

Electrical systems such as radar and communication systems require grounding. One known method (shown inFIG. 1) for grounding mobile electrical systems such as radar and communication systems has been to use a single grounding rod110. The single grounding rod may be, for example, about eight feet long, and is driven into earth. Rod110is clamped to cable112by clamp114, and has a connector116for being applied to a ground attachment of a device. One shortcoming of this method is that it is very difficult to use for rapidly deploying systems because it requires considerable crew effort and time to install the grounding rod. Another shortcoming is that such a rod is not re-usable because considerable time and energy would be required to completely pull out the grounding rod.

Another known method for grounding mobile radar and communication systems is to use a grounding kit, illustrated inFIG. 2. Such a grounding kit consists of a number of daisy chained stakes210, about 10″ (inches) long, all of which have to be installed by hand in a desired pattern. Each stake has to be individually forced into ground with the use of a hammer220and like tools. The stakes210are then connected to each other through a grounding cable240, which is further connected to ground an electrical system230. This requires substantial crew effort and time to drive each of the grounding stakes into the ground around the deployed system. Similarly, when the electrical equipment is to be redeployed or removed, all of the stakes have to be removed manually. This requires considerable crew effort and time because each stake has to be individually pulled out of the ground. It would be desirable to provide for decreased installation and removal time, both in overall time and personnel time, for devices to ground electrical equipment. This can facilitate, by way of example, deploying mobile radar, communications and other electrical systems.

SUMMARY OF THE INVENTION

An electrical grounding strip includes a first link connected directly to a second link. Each of the first and second links has a portion lying substantially in a plane and has at least one electrically conductive spike attached to the portion. The spike projects generally orthogonally to the plane. An electrically conductive flexible member, which is in electrically conductive contact with the spikes of each of the first and second links, grounds the mobile electrical system.

A method for grounding equipment includes the step of placing a strip made of a first and a second link, each of the first and second links having a planar portion and at least one spike which projects generally orthogonally from the planar portion, in a position such that each of the spikes of the first and second links is pointing toward a grounding surface, electrically connecting each of the spikes to the equipment and applying a load to each link to force each of the spikes into the grounding surface.

DETAILED DESCRIPTION OF THE INVENTION

It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, many other elements found in typical grounding methods and systems. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. The disclosure herein is directed to all such variations and modifications known to those skilled in the art.

Referring toFIG. 3, there is shown an electrical ground spike strip300in accordance with an embodiment of the invention. The spike strip300has two links310,320which are connected directly and rotatably to each other. Each of the links310,320has two spikes315each. Dependant upon the final configuration of the spike strip300, additional links310may be added to provide the required grounding. The link310with two spikes315is only illustrative. Furthermore, it is possible to have one or more than two spikes on each link310, as will be easily understood by a person of skill in the art. The spike strip300also includes a handle340which is directly and rotatably connected to link310. A flexible, electrically conductive, grounding strap330is in electrically conductive contact with each of spikes315of the links310,320, and may be provided in electrically conductive contact to the equipment which is to be grounded. In the illustrated embodiment, each of links310,320is made of a single piece of electrically conductive material, so that the illustrated physical connection between strap330and links310,320provides electrically conductive connection with spikes315.

Now referring toFIG. 4A, the link310is shown in greater detail. Three segments311,312and313form a portion317of the link310. The portion317lies substantially in a plane. In this illustrative only embodiment, the three segments311,312and313define a generally rectangular frame. Segments311and312are generally straight and generally parallel to each other, defining two opposite sides of a rectangle. In this illustrative embodiment, segment313has a central portion318which is generally straight and two curved outward extending portions314. Segment311, at its end opposite to segment313, joins an upper end of one of spikes315. Segment311defines loop or coil316of about 450 degrees. An opening defined in the center of coil316is sufficiently large to receive a rod of the same size. Portions314may be received within coils316. As an exemplary embodiment only, the spikes315may be about 8″-12″ long. The spikes315are slightly curved inward toward the portion317. Each spike has an elongated main portion of uniform diameter, and tapers to a point at a distal end thereof, opposite to the end connected to planar portion317.

In the illustrated embodiment, the three segments311,312and313, and spikes315, are formed from a single elongated and shaped cylindrical rod. However, other manufacturing methods may be used to fabricate link310. By way of example, three segments can be joined to form the portion317, and the spikes joined to the portion317, or a single elongated member can be shaped to form the link310, including spikes315, by bending, or casting or other manufacturing processes. It will be appreciated that coils316may be formed around portions314of adjoining links when spike strip300is formed. As seen inFIG. 4B, in this particular embodiment of the link connection, the coiled portions316of the spikes315are wrapped around the curved portions314of the member313to connect the link320with the link310. The connection between the links310and320is pivoting or rotatable connection. Various other known joints can also be used to connect the link310with the link320. In the illustrated embodiment of the invention inFIGS. 3 and 4B, the links310and320are identical.

Handle340, shown inFIG. 3, has a generally rectangular frame, defined by straight side segments341,342, connecting end segment343, and gripping end segment344. Handle340lies in a plane. Connecting end segment343, similar to segment313of link310(described above in connection withFIG. 4A), is generally straight with outward curving portions, that are received in coils316of link310. Handle340is thereby rotatably connected to link310. When strip300is in the ground, handle340may lie flat on the ground.

Illustrated inFIGS. 5A and 5B, is a method for grounding equipment using the rollover electrical spike strip300. The strip300is laid on ground510in a desired pattern, with spikes315of the links310,320pointing toward the ground510. Spikes315are in contact with the ground510, and are substantially supporting strip300. A load is then moved onto spike strip300. In one embodiment, the load may be a wheeled vehicle, having wheel500. The wheeled vehicle may be a self-propelled, motorized vehicle. The motorized vehicle may alternatively be a tracked vehicle. As the wheel500rolls over the strip300, it forces the spikes315into the ground500. InFIG. 5A, link310is positioned so that segment313and points of spikes315are generally in contact with the ground. As spikes315are curved toward planar portion317, the points of spikes315are substantially orthogonal to the ground. As wheel500moves forward, link310is rotated so that spikes315are driven into the ground. As the spikes of link310are driven into the ground, coils316of link310are moved to the ground. Segment313of link320, which is disposed through coils316of link316, is thus moved closer to the ground, causing link320to rotate such that the planar portion317of the link320is positioned tangentially to the wheel500and spikes315of link320are pointed closer to orthogonal to the ground, as shown inFIG. 5B. As portion317is planar, wheel500may easily continue rolling once spikes315of link310have been completely driven into the ground. The wheel500then rolls over the link320, and forces the spikes315of the link320into the ground. Similarly, as the spikes of each link are forced into the ground, the planar portion317of the subsequent link becomes tangential to the wheel500, and spikes315of the subsequent link are oriented closer to orthogonal to the ground. Since all the spikes315are electrically connected by the ground strap330(ofFIG. 3), the equipment is grounded when the ground strap is connected to the equipment.

Now referring toFIG. 6, the entire strip300is shown after each of spikes has been driven into the ground. All of the spikes315are lodged firmly into the ground. The handle340can be used to pull the strip300out of the ground when the strip is no longer needed, such as when the equipment is being moved again. Gripping segment344of handle340may be engaged and pulled upward, so that initially handle340rotates about its connection to link310. As a user continues to apply a manual or mechanical force to gripping segment344, link310, and then successively the remaining links, are pulled out of the grounding surface.

FIG. 7illustrates an electrical system700grounded employing electrical grounding spike strips in accordance with an embodiment of the invention. A wheeled vehicle710, having wheels500, carries an electrical device700, which includes a radar array710in this example. Four electrical grounding spike strips300are deployed, with the spikes315of each firmly lodged into the grounding surface510, providing good electrical contact between the spikes and the grounding surface. Grounding strap330is electrically connected to each spike strip300and to attachment720for grounding device700. Thus, device700is grounded.

An exemplary advantage of a ground strip in accordance with an embodiment of the invention is that, since the weight of a vehicle is used to embed the spikes in the ground, significant savings in crew effort and time are achieved in providing for grounding of mobile electrical devices when compared with the methods illustrated inFIGS. 1 and 2. A further exemplary advantage is that significant savings in crew effort and time are achieved in removing a spike strip in accordance with an embodiment of the invention from the ground. The use of a spike strip in accordance with an embodiment of the invention thus facilitates rapid deployment of mobile electrical systems. It is further advantageous that a grounding strip in accordance with an embodiment of the invention is reusable.

It will be apparent to those skilled in the art that modifications and variations may be made in the apparatus and process of the present invention without departing from the spirit or scope of the invention.