BACKGROUND OF THE INVENTION

Ground anchors serve as anchorage points on the ground to take up tensile loads, for ex- ample, for recovering vehicles, moving loads in the field, bracing cable bridges, masts, tents or in agriculture for securing vines or (newly planted) trees.

Percussion -(or battered down-anchors), are simple rods which - inclined against the direc- tion of pull - are driven directly into the ground.

They can regularly be dismantled again without tools as they are not secured against tension on their longitudinal axis.

A design for higher vertical tensille loads is given with ground anchors, which are screwed into the ground like ground bolts. The achievable strength is greater the deeper the thread is screwed in, the wider and longer the thread, and the firmer the soil is. These are not suitable for rocky soils or soils interspersed with large stones and leave a relatively loose soil behind.

A type for high tensile loads are impact anchors with sparks, but the removal of this type of construction is particularly intricate, since the sparks bloc the direction of tension.

Therefore reuse is only possible in exceptional cases and the ground is loosened very much on removal.

TASK OF THE INVENTION

The task of the present invention threrefore is to create a ground anchor that can be inserted and removed without damaging the ground. A further task is that it should be able to absorb high tensile loads, even in the vertical plane.

A further task is that it should be suitable for both solidified and rocky soils or soils inter- spersed with large stones.

SOLUTION

This is achieved by means of a ground anchor, which is hydraulically inserted into and re- moved from the ground. It has movable flukes at the tip and in the mid section and a remov- able ground bolt below an anchor plate. Various fastenings can be attached to the anchor plate. The movable flukes are extended after insertion via an internal auxiliary cylinder, push rods or a threaded rod and can be re- tracted again before removal.

By means of an associated hydraulic system, which can be attached to and supplied by excavators or agricultural tractors, it is possible for one person to insert and remove single or a large number of ground anchors. A further possibility of installation are the base plates of cranes or other heavy equipment.

PRIOR ART

US2681789A describes a hydraulic fence post setter and puller, here an attachment for a tractor is described, with which fence posts can be both set and pulled out again.

In US3056477A a hydraulic anchor expander with a spreader plate that can be extended from the anchor tip is described. The anchor expander is sunk into an existing hole and is only locked in place by the expansion.

The anchoring device described in FR2874036A1 with anchoring wings integrated into the anchoring body are deployed through openings by a pressing tool acting from top to bottom. The anchoring device is pressed into the ground and has stabilizers on a base plate.

The anchoring wings spread by a pressing tool are relatively long and displace a correspond- ing amount of material - a suitability for rocky subsoils is not possible, as the anchoring fails if one or more anchoring wings are blocked.

An earth pile with fluke-like folding devices described as earth nails is described in US3763655A, here the earth nails are extended via a device that moves in the pile - retrac- tion is not provided here.

DESCRIPTION ALONG TO THE DRAWING

Fig. 1 shows the ground anchor (1) consisting of anchor plate (2), anchor tube (3), fasten- ers (8) for the placement system, movable flukes (4), push rod (5), flukes spreader (6), and removable ground bolt (7).

Fig. 2 shows the ground anchor (1) in place, here the movable flukes (4) are extended.

Fig. 3 looks from above at the ground anchor (1 ) consisting of anchor plate (2), anchor tube (3), the extended flukes (4) and the push rod (5).