Methods for manufacturing a pivot and a jack a pivot and a jack

摘要

For manufacturing pivots for a jack, cylindrical work pieces (5) consisting of a ductile metallic material are prepared. Each work piece (5) is then rotated and rolled by profile rollers (13, 14), wherein at least one of the profile rollers (13, 14) is pressed against the work piece (5) by means of a hydraulic pressing and adjusting device (20). The profile rollers (13, 14) have annular ribs (17) which produce two annular grooves (31) in the work piece (15) during rolling of the latter. This makes it possible to provide the work pieces (5) rapidly and at low costs with grooves (31). Each rolled work piece (5) is then provided with a transverse hole between the two grooves. The links of the jack have fork-shaped connection portions which can be pushed over the grounds of the grooves of the pivots so that the pivots are pivotably connected with the links by a clip in operation. IMAGE