Abstract:
An adjustable ground anchor comprises an anchoring post for securement in ground, base plate fixed on the top of the anchoring post, and L-shaped brackets on the base plate. Slots in the base plate reside symmetrically in relation to the center of the base plate and extend along a line passing through the center of the base plate. Two L-shaped brackets lay on the base plate, each having a slot in the flange abutting the base plate. A through bolt is mounted through the slot in the base plate and the slot in the flange of the bracket above, wherein the slots allow the bracket to freely move on the base plate prior to tightening the through bolt. The brackets form a retaining portion for a post that is fixed between the upward pointing flanges of the brackets.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a ground anchor for securing elongated members like fence posts and poles. The ground anchor has a lower part constructed as screw anchor or tapering rod and its upper part comprises a fixing for a post or pole. 
       BACKGROUND ART 
       [0002]    Finnish patent No. 115988 describes a ground anchor, which is provided with an elongated tapering part that is driven into the ground and a connecting part. A sleeve for the post is fixed onto the connecting part. The tapering part and the sleeve are attached to each other with a bolt joint. Slots in the connecting part and the sleeve allow adjustment of the relative position of the connecting part and the sleeve before tightening the bolt joint. 
         [0003]    When only one bolt joint is used, the attachment will be under severe strain. In this case a massive bolt must be used. In practice the sleeve is also slightly larger than the post so the post can be installed inside the sleeve. Thus the post will be loose from the sleeve at some point, which weakens the joint. In addition, different size posts require their own types of sleeves. This increases manufacturing and transport costs. 
         [0004]    An objective of the present invention is to provide a new adjustable ground anchor which is more robust and more versatile than previously known ground anchors. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    An adjustable ground anchor comprises an anchoring post for securement in a ground, a base plate fixed on the top of the anchoring post, and L-shaped brackets on the base plate. Two slots in the base plate reside symmetrically in relation to the center of the base plate and extend along a line passing through the center of the base plate. Two L-shaped brackets lay on the base plate. Each bracket has a slot ( 14 ) in the flange abutting on the base plate, the slot extending longitudinally between the outer edge and inner edge of the flange but leaving sufficient material between the slot ends and the side edges of the flange to provide structural integrity. A through bolt coupling is mounted through the slot in the base plate and the slot in the flange of the bracket above, wherein the slots allow the bracket to be freely movable on the base plate prior to tightening the through bolt coupling. The brackets form a retaining portion for a post that is fixed between the upward pointing flanges of the brackets. 
         [0006]    The retaining portion according to the invention is new and surprising, offering excellent possibilities for adjusting the ground anchor. However, the structure is simple, which decreases manufacturing costs and makes adjustment easier. Adjustment can be made using ordinary tools even in field conditions. In addition to adjusting the relative position of the base plate and retaining portion, the retaining portion itself can now be adjusted, as well. Thus, the same product is suitable for different size posts. The post can also now be attached to the retaining portion more securely than before. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The invention is described more closely with reference to accompanying drawings, in which 
           [0008]      FIG. 1   a  shows a side perspective view of the ground anchor according to the invention; 
           [0009]      FIG. 1   b  shows the ground anchor of  FIG. 1 , but rotated 90°; 
           [0010]      FIG. 2   a  is a top view of the base plate of the ground anchor; 
           [0011]      FIG. 2   b  is a cross-sectional view of the base plate according to  FIG. 2   a;    
           [0012]      FIG. 2   c  shows the parts of the retaining portion of the ground anchor viewed from different directions according to the invention; 
           [0013]      FIG. 3   a - 3   f  shows a side view of the ground anchor according to the invention; 
           [0014]      FIG. 4  shows an example of an implementation of the ground anchor according to the invention; 
           [0015]      FIG. 5   a  depicts a fence element viewed from the side; 
           [0016]      FIG. 5   b  depicts how two fence elements of  FIG. 5   a  are fitted together. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1   a  shows the adjustable ground anchor described in these specifications. Here the ground anchor also has anchoring post  10  made from steel plates that have been welded together to form a anchoring post having X-shaped cross section. The anchoring post can also be constructed as screw anchor with a cylindrical shank and a helical ridge formed on the shank. The anchoring post is tapered so as to ease driving it into the ground. The ground anchor also has base plate  11  and retaining portion  12 . The retaining portion is intended for the post and is attached to the base plate. Base plate  11  also has first slot  13  and retaining portion  12  has second slot  14  ( FIGS. 2   a - 2   c ). A through bolt  15  is fitted through slots  13  and  14  ( FIG. 1   a ). The slots and the through bolt are meant both for adjusting the relative position of base plate  11  and retaining portion  12 , and for locking base plate  11  and retaining portion  12  together. In other words, the slots enable movement of the retaining portion in relation to the base plate, and vice versa, before the through bolt is tightened. Thus, any deviations in measurements or direction between the ground anchor and a post can be compensated for. 
         [0018]    Retaining portion  12  is composed of two separate L-shaped brackets  16  for adjusting the size of retaining portion  12 . The base plate also has slots  13  and a through bolt  15  for each L-shaped bracket  16 . The optimal grip on the post can be achieved with the two separate L-shaped brackets. The L-shaped brackets can also be set in different positions, meaning that one type of retaining portion is suitable for a number of posts of different sizes and shapes. The support provided by one L-shaped bracket may not be sufficient, but two L-shaped brackets provide support in all directions. The L-shaped brackets presented in these applications are right-angled, but they can be bent during installation. Thus the post can be vertical and straight even if the anchoring memeber was driven in slightly askew. 
         [0019]      FIGS. 1   a  and  1   b  show the movement possibilities for the L-shaped bracket. Each L-shaped braket profile can be moved in linear fashion in two different directions, which are at right angles to each other. The through bolt coupling also allows the L-shaped bracket to be rotated at the same time. The slots and the other L-shaped bracket limit movement. If necessary, the through bolt can be opened and the L-shaped bracket turned. 
         [0020]      FIG. 2   c  shows two L-shaped brackets  16  viewed from three different directions. Slot  14  is on the shorter flange  17  of L-shaped bracket  16 . Longer flange  18  of L-shaped bracket  16  has several holes  19  for fastening the post. Screws can be used for the smaller holes, while the large hole is big enough for a threaded rod. Dimensions of the flanges of the L-shaped brackets are optimised in order to achieve sufficient sturdiness and wide adjustability. A slot, for example, can also be in both flanges. The sharp corners of the flanges can also be rounded off in order to improve the L-shaped bracket&#39;s manoeuvrability. At the same time, the risk of accidents can be avoided when installing the ground anchor or moving around close to it. 
         [0021]    Optionally, the edges of base plate  11  may be bent to form bent edges  21 . This increases the rigidity of the base plate. Dash-dotted diagonals in  FIG. 2   a  indicate areas where the uppermost edges of the anchoring post having X-shaped cross section are welded. The uppermost edges of the anchoring post positioned cross-wise in relation to the slots, in order to leave the bolts sufficient room for movement. At the same time, the plates make the base plate even more rigid. 
         [0022]    When all edges of the base plate are bent, the load bearing capacity in the areas near each slot is about the same. In addition, the bent edges hide the uppermost portion of the anchoring post when it has been driven into the ground. 
         [0023]      FIG. 2   c  shows fastener  15  for attaching the L-shaped bracket to the base plate. The fastener comprise bolt  23  and nut  24 . The brackets are set on the base plate so that the slots in the flange at least partially overlaps the slot in the base plate. Therafter the bolt is inserted from underneath through the overlappig slots and the nut is screwed opposite the bolt. Washer  26  is put under the nut. However, the nuts are tightened slack thus allowing adjustment of the brackets along the surface of the base plate. Not until the proper locations of the brackets corresponding the post to be fixed are found, the nuts are tighten firmly. 
         [0024]    Preferably bolt  23  has square shoulder  25 , which is designed to fit in slot  13  of base plate  11 . Thus the bolt can slide in the slot but is prevented from rotating. Thus the bolt joint can be tightened using a single tool.  FIG. 2   a  also shows other slots  27  in base plate  11  for both L-profiles  16 . Other slots enable even more versatile positioning for the L-profiles. Additional bends can be made to a simple L-shaped bracket, thus improving the ability to affix the post and/or the retaining portion&#39;s suitability for different posts. 
         [0025]      FIG. 3   a  shows the first example of L-shaped bracket positioning. Here L-shaped brackets  16  are parallel and the upward pointing flanges are pointing to opposite directions, so large post  28  can be fastened between the flanges. 
         [0026]    The situation in  FIG. 3   b  could occur next. Here both L-shaped brackets  16  have been pressed tightly into post  28  and L-shaped brackets  16  have also been moved towards the edge of the base plate. Thus the post is in the desired position and the nuts can now be tightened. In  FIGS. 3   a  and  3   b  the retaining portion has been measured for a post having square cross section. 
         [0027]    In  FIG. 3   c  L-shaped brackets  16  are parallel and the upward pointing flanges are pointing to the same directionso a post having rectangular cross section can be fixed in between the flanges. Here L-shaped brackets  16  have been turned and thus pole  28  can be turned in order to achieve the required position. If necessary, the long flanges of the L-shaped brackets can be set opposite one another, in which case a plank or a board can be attached to the retaining portion (not shown). 
         [0028]    In  FIGS. 3   d  and  3   e  L-shaped brackets  16  have been positioned perpendicular to each other, which can be used, for example, in the corners of fence structures or other buildings. 
         [0029]    In  FIG. 3   f  one of the L-shaped brackets  16  is attached to alternative slot  27 . For the sake of clarity, the bolts and nuts are not shown in  FIGS. 3   a - 3   f.    
         [0030]      FIG. 4  shows part of fence  29 , where posts  28  have been fixed to the ground using the ground anchors described in these specifications. Here, post  28  is formed by two planks  30 , each of which is a fixed part of a separate fence element. Thus by attaching two planks to each other, two consecutive fence elements are attached to each other, as well. In this way, separate posts are unnecessary and the fence will look finished and uniform on both sides. Due to the adjustable retaining portion, as described in these specifications, a single vertical plank can also be used as a functional post. 
         [0031]      FIG. 5   a  shows a fence element where horizontal planks  31  are attached to vertical planks  30 . Horizontal planks  31  are attached only on one side of vertical planks  30  about half-way up vertical plank  30 . By properly combining these fence elements, fences can be constructed quite quickly without separate posts. Functional post  28  is made when vertical planks  30  are positioned opposite each other as shown in  FIG. 5   b  . Horizontal planks  31  of the fence element will remain between the vertical planks. 
         [0032]    For the sake of clarity,  FIG. 5   b  shows the fence elements slightly apart from each other, but in a completed fence vertical and horizontal planks are tightly attached to each other. The ground anchor described in these specifications is attached to vertical planks. Plywood, for example, can be used instead of horizontal planks. Horizontal planks can be attached to the plywood. If at all possible, the ground anchor is driven deep enough into the ground that the base plate is level with the surface of the ground. The post&#39;s upright position is adjusted primarily by selecting a suitable fastening point for the post in the retaining portion. The ground anchors can always be driven into the ground in advance and then adjusted to their exact positions when the fence elements are installed. 
         [0033]    A post, in this context, refers to many different types of long, narrow pieces, such as posts, pillars or beams. Adjustability also allows planks and boards to be supported. The necessary strength of material for plate parts depends on the application, but a ground anchor made of 5 mm plate, for example, is sufficiently durable in most common conditions. This thicknes also enables the bending of L-shaped brackets on site. After bending and welding, the various parts are galvanized for a longer life. The structure of the ground anchor described in these specifications is simple but durable, and can be produced using components already on the market. The simple structure is easy and economical to manufacture.