GB296380A - Improvements in web-connecting mechanism for printing presses, and other web fed machines - Google Patents

Abstract

296,380. Scott, W. C. March 25, 1927. Feeding webs.-In means for attaching a new web to an expiring web being fed to a printing or other machine, particularly as described in Specification 292,693, the new web being attached to a portion of surplus web accumulated from the active roll, the attaching-device comprises two opposed members on the outer sides of the two overlapping webs, and movable lengthways of the webs, the members being first brought together and then separated while moving in one direction, and maintained separated while moving in the opposite direction. The active web 9, Fig. 1, passes to the printing or other machine 1 from a roll 2 round stationary rollers 10 to a surplus accumulating device comprising a series of rollers 11 mounted on a carriage 12 which can be reciprocated on guides 13. The carriage 12 is actuated by an endless chain 17, the driving sprocket 19 of which may be driven in either direction by connecting a clutch to either of two bevel pinions 33 on a driven shaft 31. The clutch is closed manually, but is automatically opened at the end of each stroke ot the carriage by means of a slidable rod 36 engaging the clutch lever 33 and operated by the engagement, of the carriage with collars 39 thereon; alternatively, a single bevel wheel 33 only is employed, the chain travelling in one direction and imparting a complete reciprocation to the carriage before the clutch is opened. The means for attaching the new web 62 from a roll 3 to the expiring web 9 comprises a pair of rollers 45, 46, Fig. 8, mounted in slots in a carriage 48 and pressed towards each other by springs 49. The carriage can slide vertically in guides and normally rests in its lower position in which the rollers are pressed apart by a wedge 61, Fig. 1. The expiring web and the new web pass between the rollers 45, 46 and the pasted end of the new web is held upon the appropriate one of two tables 66 by slotted links 72 to arms 71 on the rollers 45, 46. The carriage is connected by a link 51 to a bell-crank lever 52 co operating with a cam 53 geared to the sprocket 19 in snch a manner that when the web is brought to rest or to a very low speed by the action of the rollers 10, 11, the cam raises the carriage 48 allowing the rollers to be pressed together. releasing the end of the new web and then rolling over the webs to press them together. Towards the upper end of the stroke of the carriage 48, the rollers engage a second wedge 63 which separates the rollers to a greater extent than the wedge 61, allowing a spring latch to enter between the rollers to hold them apart on the down stroke of the carriage 48. This latch is withdrawn by engagement with a projection on the wedge 61. The old web may be severed automatically on the rise of the carriage 48 by one of a pair of knives 4, 5, Fig. 12, slidable on supports 74 and actuated by a lever 79 operated by a pin 76 on a rod 75 raised by the carriage 48. The levers 79 normally rest on sup- . ports 81 and are pivoted to bell-crank levers 80 connected by links 83 to bell-crank levers 82 carrying rollers resting upon the rolls 2, 3. The lever 79 is thus held away from the path of the pin 76 until the roll is of small diameter, so that only the knife adjacent to the expiring web is actuated. The change over from an expiring roll (,o a new roll may be effected automatically by devices adapted to operate the clutch lever when the roll of the expiring web is sufficiently reduced in diameter. These devices comprise a bell-crank lever, one arm of which constantly engages the web roll and the other arm of which is adapted to operate, through a spring rod, a lever operatively engaging the clutch lever. The web rolls may be provided with brakes of the construction described in Specification 292,693.