Patent GB-292693-A (GB)
Title: Method of and means for joining two webs of flexible material
IPC: B65H19/18
Filed: 1927-03-25
Abstract: 292,693. Scott, W. C. March 25, 1927. Feeding webs.-A new web is attached to the expiring web being fed to a printing or other machine, without stopping the machine, by accumulating surplus web from the active roll, allowing the surplus to be drawn upon by the machine so as to arrest or reduce the speed of a portion of the web, and then attaching the new web to such portion. The active web 2, Fig. 1, passes from a roll 1 round guide rollers 3 - - 7 to the printing or other machine. Between the rollers 6, 7 the web passes over a stationary roller 11 and under a pair of rollers 12, 13 mounted on a carriage 9 which can be reciprocated on guides 10. The normal position of the carriage is that shown, but when the web 2 is nearly expired, the carriage is moved downwardly so that the rollers 12, 13 form loops in the web. As the carriage rises, the machine, which continues to run at full speed or at a reduced speed, draws its supply from the loops and the part of the web to the rear of the roller 6 is brought to rest or substantially so. The end of the web 37 from the new roll 38, previously passed round guides 39, 40, 41, is then pasted or otherwise attached to the expiring web which is then severed. The carriage 9 is actuated by a block 24 engaging a guide slot 23 in the carriage and carried by an endless chain 18, the driving sprocket 16 of which is geared to a shaft 21 which, upon operating a clutch lever 28, is connected to a driven shaft. A roller 34 on the lever 28 normally engages a notch 33 in a disc 27 connected by gearing to the sprocket wheel 17 of the chain 18. When the lever 28 is operated to close the clutch, the roller 34 is withdrawn from the notch 33. The circular part of the disc then engages the roller to hold the clutch closed until the carriage has made a complete movement down and up, when the roller re-engages the notch and again opens the clutch. The means for attaching the new web to the expiring web comprises a pair of rollers 44, 45, the bearings of which are mounted in slots 47 in a carriage 50 and pressed towards each other by springs 48. The carriage is mounted for vertical movement and normally rests in its lower position in which the rollers are pressed apart by a wedge 49. The expiring web and the new web pass between the rollers 44, 45 and the pasted end of the new web is laid upon a support 42. When the carriage 9 moves downwardly, a hook 53 pivoted thereto engages beneath a projection 51 on the carriage 50 so that upon the rise of the carriage 9 the carriage 50 is also raised. As the rollers 44, 45 leave the wedge 49 the end of the new web is drawn off the support 42 into contact with the expiring web and the rollers are pressed together by the springs 48 to cause the webs to adhere. A finger 55 on the hook 53 then engages a fixed pin 56 to release the carriage 50 to allow it to fall back to its original position. The change-over from an expiring web to a new web may be effected automatically by devices adapted to operate the clutch lever 28 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 connected to the clutch lever. In a modification, Fig. 12, two surplus-accumulating devices are provided comprising two rollers 103, 103<a >mounted on a carriage 102 and a roller 105 on a carriage 104. These carriages are adapted to be operated by suitable means so that the accumulation of the web by one device takes place during the paying- out of the web by the other device, and the normal position of the parts is that shown in full lines. The web-attaching device comprises a pair of pivoted jaws 108, 109 provided with grippers 122 to hold the pushed end of the new web and with arms 112, 113 carrying rollers 114, 115, Fig. 13, in the path of cams 116, 117 on the carriage 102. Driven rollers 118, 119 are adapted to be thrown into contact with a new roll to assist in starting its rotation. When the carriages 102, 104 are operated, the part of the web between the jaws 108, 109 is brought to rest and as the cams 116, 117 move past the rollers 114, 115, the jaws are closed to adhere the webs and are then re-opened. The expiring web is then severed by actuating the appropriate knife 120, 121. In another modification similar to that shown in Fig. 12, the roller 105 is mounted on the carriage 102 instead of on a separate carriage 104. The web rolls may be provided with brakes 84, Fig. 7, automatically controlled to keep the web tension constant, by the movements of a roller 5 resting on the web. The roller is carried by arms 75 on a shaft 76 having an arm 82 engaging the brake lever 83 kept in contact with the arm 82 by a spring 85. The web-accumulating devices when applied to a printing-machine may be arranged between the printing-cylinders and the folding-apparatus, in which case the folding-apparatus is slowed down or the printing- cylinders are speeded up to allow the web to be accumulated, after which the printing-cylinders are stopped or retarded to slow down the web to allow the new web to be attached thereto, while the folder continues tc run, drawing its supply from the accumulated web. Specification 296,380 is referred to.