Compression wedge

A wedge comprising a first wedge element, a second wedge element, a third wedge element, and a fourth wedge element, wherein:

• (a) the first and second wedge elements are arranged moveable towards and away from each other, the third and fourth wedge elements are placed on opposite sides of the first and second wedge elements and abutting the first and second wedge elements along sloping surfaces, and the wedge elements and the sloping surfaces are so arranged that the third and fourth wedge elements move away from each other when the first and second wedge elements are moved toward each other and the third and fourth wedge elements are free to move toward each other when the first and second wedge elements are moved away from each other;
• and
• (b) the first and second wedge elements move towards and away from each other by means of a first part comprising a socket arranged rotatable but fixed in relation to the first wedge element and a second part comprising a screw arranged non-rotatable and fixed in relation to the second wedge element, wherein the second and first parts have threads in mesh with each other and that the wedge is movable between two extremes, which extremes each is defined by one stop edge of the screw and a stop edge of an adjacent part.