GB827341A - Continuous rolling mill of the reducing type for tubes - Google Patents

Abstract

827,341. Rolling. INNOCENTI SOC. GENERALE PER L'INDUSTRIA METALLURGICA E MECANNICA, and CALMES, A. Nov. 14, 1957 [Nov. 28, 1956], No. 35481/57. Class 83 (4). A continuous tube rolling mill comprises a series of roll stands operated by regulable speed motors each driving a group of at least two consecutive stands, each group of stands 1, 2 comprising a first and second pair of reducing rolls 25, 24, drive shafts 2a, 1a (Fig. 1, not shown), for the rolls, a first set of exchangeable gear-wheels 9, 10, 11, 12 positioned on one side of the group establishing a basic transmission ratio between the associated motor and the drive shafts for the rolls, gearing 14, 15, 16, 17 driven from the first set of gears which drives the drive shaft 2a for the first pair of rolls 25, a transmission shaft 18 between the gearing 16, 17 and a follow-up shaft 21 which is parallel with the shaft 18 and in driving connection with the driving shaft 1a for the second pair of rolls 24 and in a recess 22 in the structure a second set of exchangeable gear-wheels 19, 20 connecting the transmission and follow-up shafts and establishing a secondary transmission ratio for the second pair of rolls. In the form shown in Fig. 2 six rolling stands 1-6 arranged with the axes of their rolls 24-29 inclined to the horizontal in alternating directions are driven in pairs by three motors 8. The drive shaft 2a in each of the even-numbered stands is driven through bevel gears 14, 15, while that in each of the odd-numbered stands is driven through bevel gears 141, 151. The recess 22 is fitted with a readily removable cover 23. The motors are such that their relative speed ratios remain fairly constant after regulation whatever the load imposed on them. In the embodiment in Fig. 3 (not shown), a single motor drives a central stand and two side stands.