The invention relates to a device for straightening of pipes, especially for straightening of bentj tubular road sign posts.

By straightening of bent pipes a device is used that com¬ prises two bases placed on each side of the bending on its outside. This device can not be used for straightening of bent road sign posts _. , where the bending ^' is near the surface of the earth.

The purpose of this invention is to present a device to meet this disadvantage.

This is achieved when the device comprises a base in two parts to span the bent pipe on one side of its bending, which base is connected to one end of at least one bar. the other end of which is pivotally fastened to a piston rod in a working cylinder _. , which is pivotally fastened to a corner of a triangular straightener, another corner being pivotally fastened to one part of the base, and the side opposite this corner being the basis for a thrust block or roller arranged in a way that allows this to press against the other sice of the bending of the pipe. Thus the device can be easily placed on a pipe that is to be straightened. The base is placed immediately under the bending, and thus benilngs close to the earth can be straightened.

According to claim 2 the divice can be characterized in that the bars are pivotally fastened to each its on opposite sides of the pipe gripping tight-fitting thrust pad of the base, and that the bars are connected to the piston rod in the sar.e point, the lengths of the bars be¬ ing fitted to allowing the thrust pads to squeeze the pipe, as the bars for- an acute angle to each other. This

embodiment is especially appropriate., as the base in tw parts automatically tightens round the pipe when acti¬ vating the working cylinder of the device.

Finally, ^' -according to claim 3, the device can be charac terized in that the thrust block or roller can be faste to the side of the triangular straightener that is oppo te the corner where the triangular straightener is con¬ nected to the base at different distances from the thir corner of the.-triangular straightener. By means of this heavily bent pipes can be straightened, even if a worki cylinder with a limited length of .stroke is used.

The invention will be further explained with reference the drawing _. , showing an embodiment according to the inv tion, seen from the side.

The device consists of a triangular straightener 7_ 1*4, to the lower corner 6 of which a thrust pad 3 is pivota fastened to fit tightly against a pipe 1 at the inside of the bending. At the other corner 8 a pneumatic or hy-r draulic working cylinder 9 is pivotally fastened, the pi ston rod 10 -of which is pivotally fastened to two sets o bars 11 and 12. One set of bars 11 are at the other end fastened pivotally to the corner 6 and the base 3. To t other set 12 another thrust pad 2 is mounted, pivotally at the other end 1*4 to fit tightly against the pipe 1 at the outside of the bending. Finally thrust roller 5 is mounted on one side 7 of the triangular straightener. Th thrust roller 5 can be moved between several positions 1 at different distances from the corner -4.

The device functions in the following way. The base 2, 3 in two parts is placed round the pipe 1 immediately belo the bending so that the thrust roller 5 abuts the pipe 1 above and at the inside of the bending. When activating the working cylinder 9 the thrust pads 2 and 3 are press firmly round the oioe 1, whereuoon-'the stra ghte-

ner turns about the corner 6 . the thrust roller 5 trans¬ mitting the straightening power from the working cylinder 9 to the pipe, which is then straightened, as the neces¬ sary reaction against the pipe 1 is transmitted through the thrust pad 2.