GB670236A - Arrangement in pilgrim rolling mills for the production of conical tubes or tubes with conical portions - Google Patents

Abstract

670,236. Rolling tubes. SEE FABRIKS AKTIEBOLAG. March 2, 1948, No. 6601/48. Class 83 (iv). A pilger mill, for the cold rolling of taper tubes, and of the type in which segmental rolls are mounted in a housing reciprocating with constant stroke, has means for automatically varying the initial position of the rolls. Roll segments 7 intergeared at 9 are mounted in a housing having rollers 3 running on ways 4 (not shown) to facilitate reciprocation by a crank and connecting-rod 6. Pinions 35 on extensions of the lower roll journals engage racks 10 slidable in the main frame under the control of pinions 11 and racks 13 carried by a crosshead 14 on a screw 15 engaging a bevel wheel nut 16 geared to a shaft carrying oppositely disposed ratchet wheels 20, 20a driven by pawls 21, 21a on levers linked to a lever 24 pivoted at 25 and swung in one direction by an adjustable stop 27 on the housing and in the other by a spring (not shown). The screw 15 has a left-hand thread and to cause a taper in the direction shown in Fig. 1 in that part of the tube between the rolls, the pawl 21 is in operation so that in each successive stroke the maximum diameter of the pass comes into action later after an increasing amount of idle stroke and rolling ceases at a correspondingly greater distance from the smaller end of the pass. By rendering the pawl 21 inoperative and the pawl 21a operative the reverse effect is obtained and the taper produced is in the opposite direction.