| 摘要 |
A rolling stand (1) with three working rolls (5, 6, 7) for rolling seamless tubes with mandrel, the rolling stand defining a rolling axis (X) and comprising a bearing structure (3), three working rolls (5, 6, 7) each having a respective median plane lying on the rolling axis (X), wherein the median planes form an angle of 120° with each other, each of said three working rolls having a respective chock (11, 12, 13), a roll-holding cartridge (2) wherein said three working rolls (5, 6, 7) and said chocks (11, 12, 13) are accommodated, a locking device (20) for locking the position of said chocks (11, 12, 13) within the roll-holding cartridge (2), in order to lock the chocks (11, 12, 13) in a respective first radial position which allows an extraction of the roll- holding cartridge (2) from the bearing structure (3) and an insertion of the roll-holding cartridge (2) in the bearing structure (3) in a direction transversal to the rolling axis (X), wherein said locking device (20) comprises three stopping pins (15, 16, 17), fastened to the roll- holding cartridge (2), and control means (14) connected to the three stopping pins (15, 16, 17) by means of a kinematic mechanism which allows a combined actuation of the three stopping pins (15, 16, 17) so that each of the three stopping pins (15, 16, 17) locks a respective chock (11, 12, 13) in said respective first position. |
