GB1296938A - - Google Patents

Abstract

1296938 Lateral edge adjustment of web materials G STUMPF 19 April 1971 [9 Dec 1970] 21612/71 Heading D1S [Also in Division B8] Apparatus for laterally adjusting the edge position of a web material to be unwound from a supply roll 6, especially in cloth layering machines, in which the supply roll is arranged secure against axial displacement on a supporting rod 1, which is mounted near its ends, and in which drive means controlled by photoelectric pulses are used to effect the adjustment, is characterised in that the drive means are two single-acting, pneumatic cylinders 7 one cylinder being fast on each side of the rod 1 and in alignment therewith, the arrangement being such that the movable operating push rods 8 of the two cylinders 7, in their rest position, clamp the rod 1 with the supply roll 6 axially and hold an unwound web of material in a middle position. The rod I is mounted to slide freely in support brackets 2 fixed to vertical uprights 3, the support brackets 2 being provided with a suitable synthetic plastics lining. The cylinders 7 are preferably connected to an electromagnetic valve containing two electromagnetics which are connected to two photoelectric devices positioned one at each edge of the web. Should the web shift laterally, pulses from the photoelectric devices operate the electromagnetics to supply air to the appropriate push rod 8 to shift the supporting rod I to correct the lateral shift in the web. The photoelectric devices are preferably in the form of forks with the web edges passing between the prongs of the forks.