Patent ID: 9079230
Filing Date: 2015-07-14
Classification: B21B

Abstract:
1. A rolling stand with three working rolls for rolling seamless tubes with mandrel, the rolling stand defining a rolling axis and comprising a bearing structure, three working rolls each having a respective median plane lying on the rolling axis, wherein the median planes form an angle of 120° with each other, each of said three working rolls having a respective chock, a roll-holding cartridge wherein said three working rolls and said chocks are accommodated, a locking device for locking the position of said chocks within the roll-holding cartridge, in order to lock the chocks in a respective first radial position which allows an extraction of the roll-holding cartridge from the bearing structure and an insertion of the roll-holding cartridge in the bearing structure in a direction transversal to the rolling axis, wherein said locking device comprises three stopping pins, fastened to the roll-holding cartridge, and control means connected to the three stopping pins by means of a kinematic mechanism which allows a combined actuation of the three stopping pins so that each of the three stopping pins locks a respective chock in said respective first position.