with a certain tension tension component 22 can be formed in various different forms such as leaf spring spiral spring bending chock etc again as it is seen in fig3 a 3 b alternative and in fig8 a the tension adjustment of the bearing unit 15 and the bearing body 15 1 pushed upwards via a tension component 22 is provided with the help of a fixing component 19 which preferably a screw moreover in order to make distance adjustment between the said bearing unit 15 and the bearing body 15 1 and the pressure arm 3 an adjustment component 19 1 is placed on the bearing body 15 1 in the said placement operation the adjustment component 19 1 is fixed on the pressure arm 3 found below in a vertical form from the hole housing opened on the bearing body 15 1 the adjustment component 19 1 is preferably in a screw form and it keeps the bearing unit 15 and the bearing body 15 1 and the pressure arm 3 in a certain distance if adjustment is not made at the same time it also limits the tension component this component 19 1 by being rotated to the left or right provides an adjustment operation by increasing.