Assembly to lay a web material in zigzag folds has a main feed and a laying feed to carry the material between them with a reciprocating laying motion and a clamp to shear the trailing end

摘要

The assembly to lay a web material (7) in zigzag folds has a main feed (8) and a laying feed (13), which pass around rollers (11,12,14,16,20) and carry the material between them. The rollers for the main feed are on fixed axes (9,10) and at least one roller of the laying feed is the laying roller, with a reciprocating movement between the main feed and the receptacle (4). A further roller of the laying feed also has a reciprocating movement as a counter roller against the laying roller, and they are coupled together by a flexible belt (17) around a deflection roller (18) to give them their opposing movements. The laying roller is operated by a cyclic drive, acting on the connecting belt or the laying feed. The drive has a speed control to give a variable speed within a working cycle. A roller of the main feed is a feed roller, with the laying feed around it on the side towards the material being laid. The feed roller has at least one mantle opening as a groove around its circumference, with a width and depth at least matching the dimensions of the laying feed which rides within the groove. At the end of laying, a clamp grips the material against a counter pressure unit, and the material shears, using the laying roller or a counter pressure roller (25) synchronized with the laying roller, to act with the clamp. The clamp is a clamping roller (24), rotating at a different speed from the main feed speed, and with a reciprocating movement, operated by a control and a drive. The clamping roller is held under a spring tension. The material is inserted into the assembly, with a control to ensure that the new feed is gripped and which works with a sensor to register the presence of the leading end of the new material.