Ground anchor

Abstract

Ground anchor designed to be screwed into the ground, comprising a shaft ( 3 ), whose upper end ( 8 a ) is provided with a bearing part ( 8 ) that can be placed on the ground, and a manipulation device ( 9 ). Said anchor has several screw-thread blades ( 5, 6, 7 ) consisting of a flat material, which spiral around the shaft ( 3 ), are arranged along the shaft ( 3 ) at a distance from one another in an offset manner, and respectively consist of a screw thread with upper and lower blade ends ( 11, 12 ). The length of the thread of the individual blades ( 5, 6, 7 ) slightly exceeds 360°, so that the perimeter of the blade ends ( 11, 12 ) overlaps, forming a cutting gap ( 11 a ) that is delimited by a plane on its upper and lower borders. The exterior diameter of the blades ( 5, 6, 7 ) decreases from blade to blade from the bearing part ( 8 ) down towards the lower end of the shaft. The shaft tip ( 22 ) is configured in the same manner as a wood-screw shaft, with a conical core ( 23 ) that tapers towards the tip of the free lower shaft end ( 25 ) and a continuous thread ( 27 ) spiralling around said core ( 23 ).

1 . A ground anchor for screwing into the ground, which is divided into a bearing part ( 8 ), a shaft ( 3 ) and a shaft end ( 21 ), 
 wherein the ground anchor has in the region of its upper end ( 8   a ) a bearing part ( 8 ) that can be placed on the ground ( 8 ) and a manipulation device ( 9 ),    comprising a plurality of screw-thread blades ( 5 ,  6 ,  7 ) consisting of a flat material, which spiral around the shaft ( 3 ), which are arranged along the shaft ( 3 ) at a distance from one another in an offset manner, and which respectively consist of a screw thread with upper and lower blade ends ( 11 ,  12 ), wherein the thread length of the individual blades ( 5 ,  6 ,  7 ) slightly exceeds 360° so that the blade ends ( 11 ,  12 ) overlap in the circumferential direction, forming a cutting gap ( 11   a ) that is delimited by a plane on its upper and lower borders, with the outer diameter of the blades ( 5 ,  6 ,  7 ) decreasing from blade to blade from the bearing part ( 8 ) down towards the lower shaft end ( 21 ), and    a shaft end ( 21 ) with shaft tip ( 22 ),    characterised in that    the shaft tip ( 22 ) is fitted with a conically tapering core ( 23 ) at the free lower shaft end ( 25 ) and    the shaft tip ( 22 ) is constructed in the fashion of a wood screw shaft with a continuous screw thread ( 27 ) spiralling around the conically tapering core ( 23 ),    wherein the screw thread ( 27 ) has a wedge-shaped cross-sectional profile from the core ( 23 ) outwards.    
     
     
         2 . The ground anchor according to  claim 1 , characterised in that the helix angle of the screw thread ( 27 ) in the region of the core ( 23 ) of the shaft tip ( 22 ) is larger than the helix angle of the blades ( 5 ,  6 ,  7 ) arranged at an angle.  
     
     
         3 . The ground anchor according to any one of claims  1  and/or  2 , characterised in that the height of the screw thread ( 27 ) remains substantially the same except for the run-out area at the free end ( 25 ) of the shaft tip ( 22 ).  
     
     
         4 . The ground anchor according to any one or more of the preceding claims, characterised in that the shaft tip ( 22 ) is arranged precisely centred on the shaft ( 3 ).  
     
     
         5 . The ground anchor according to any one or more of the preceding claims, characterised in that a ball socket ( 14   a ) in the movable head ( 13 ) of the manipulation device ( 9 ) can be stopped in a set head position by means of a clamping screw ( 20 ).  
     
     
         6 . The ground anchor according to any one or more of the preceding claims, characterised in that the clamping screw ( 20 ) is a headless screw.  
     
     
         7 . The ground anchor according to any one or more of the preceding claims, characterised in that the lowest ( 7 ) of the blades ( 5 ,  6 ,  7 ) arranged at a distance has a greater bend at the lower edge ( 12   b ) compared with the other blades ( 5 ,  6 ,  7 ) arranged at a distance.