GB787995A - Improvements in or relating to tensioning rollers for stretching webs of material - Google Patents

Abstract

787,995. Stretching webs transversely. BECHTER, H. Oct. 18, 1954 [Oct. 22, 1953; July 6, 1954], No. 29921/54. Class 100(1) A tensoning roller for transversely stretching webs, comprises a shaft carrying interchangeable tubular bushes some or all of which are externally threaded. A support shaft 17, Fig. 8, carries interchangeable tubular bushes 18a, 18b over which the web is guided, some of the bushes being externally threaded, the bushes from the centre of the roller towards one end being provided 'with right hand threads and those towards the opposite end with left-hand threads, the pitch of the threads increasing from bush to bush from the .centre towards each end. As shown in Fig. 2, a web passes over a guide roller beneath a tensioning roller 2 and over a guide roller 3. The roller 2 is supported by a transverse support 12 secured to flanges 11 each adjustable vertically of a bracket 6 by means of a slot 9 and clamping screw 13. The bracket 6 is horizontally adiustable along a frame 5 by a slot 7 and clamping screw 8. The bushes 18a, 18b, Fig. 8, have multi-start left and right hand screw threads respectvely, the pitches of which increase towards the roller ends. In a modification, Fig. 7, (not shown), the bushes may occupy nearly the entire length of the supporting shaft, the threads thereon being multistart and the number of starts increasing towards one end. The tops of the threads are preferably flattened as in Fig. 15 (not shown). In a further embodiment, Fig. 13 (not shown), threaded bushes are provided at the extreme ends of the roller, the remaining bushes being curved or tapered so as to form a tapered roller. In a further embodiment, Fig. 16 (not shown), a shaft carrying the tubular bushes is mounted on arms for vertical adjustment to permit variation in the tension on a web being stretched. Specification 642,721 is referred to.