Patent GB-254901-A (GB)
Title: Improvements in web renewing mechanism for printing machines
IPC: B65H19/18
Filed: 1925-08-25
Abstract: 254,901. Hoe & Co., Ltd., R., (Hoe & Co., Inc., R.). Aug. 25, 1925. Feeding webs.-In a web-roll changing-mechanism for a printing-press, the support for the roll in use is mounted in such a position relatively to the reserve roll that as the roll decreases in size the web moves bodily into a position whereby it can be joined to the new roll without substantial movement of the web out of its path. Means are provided for moving the reserve roll into the running position, discharging the spindle of the expired roll, and raising a new reserve roll into position. A braking-device, the pressure of which upon the roll automatically decreases as the size of the roll decreases, is also provided. When applied to a press having a number of printing sets each fed from a separate roll, means may be provided for changing the rolls of all the sets simultaneously. A roll 24 in use is supported in bearings 25 below and to one side of a reserve roll 6 carried on brackets 3 having inclined top rails 4. A second reserve roll 6<1> is mounted on the rails 4 but is prevented from moving into contact with the roll 6 by a stop lever 7, mounted on a pivot 9, and held in stopping position by a spring 12. The roll 6 is held at the front end of the rails 4 and at the tap of an incline 39 by a stop 17 on a segment 15 which is mounted, on a rock-shaft 16 and held in operative position by a roller 22, carried by a bell-crank lever 21, 19. engaging a cam face 18 on the segment. The web from the roll 24 passes to the press over a guide roller 101 and as the roll decreases in size, the web approaches the roll 6 until when the web has nearly expired it is closely adjacent that roll. The press is then stopped, paste is applied to the old web, the join effected, the old web severed. and the press restarted. The roll 6 is then moved down the incline 39 to the bearings 25, this movement being effected by gravity and controlled by blocks 29 movable on guides 28 and raised and flowered by cables 36. When the blocks 29 reach their upper position they engage the arms 19 of .the bell-crank levers 21, 19 and move the rollers 22 against the action of springs 23 clear of the cam-faces 18. The segments are then turned by a hand-lever 57 acting through linkage 50, 49, 48, 46, 45, 44 to release the roll 6, which then rests by its spindle 5 in grooves 30 in the blocks 29. This movement of the segments also depresses the stop lever 7 by the engagement of the cam face 18 with a roller 11 on an extension 10 of the lever. At the same time a link 65 connecting the members 45, 46 to the bearings 25 turns these bearings in their supports 26 to discharge the spindle of the spent roll, which runs down inclines 60 on to rails 33, coming to rest against stops 63. While the blocks 29 are being lowered a spring 55 acting on the link 49 and the springs 23 and 12 return the segments 15, bearings 25, bell-crank levers 21, 19, and stop lever 7 to normal positions, and the roll 6<1> moves into the position previously occupied by the roll 6. A latch 501 carried bv the hand-lever 57 serves to lock all these parts in the normal position. The knife 75 for severing the old web is carried by a bar 72 mounted to travel freely on a shaft 71 and adapted to be traversed thereon by a handle 74. Tension is exerted on the web by bolts 76 engaging the roll surface and driven at a speed slightly less than the speed of the web. The belts pass round pulleys 78 on a driven shaft 79 and round pulieys 83 carried by arms 84 secured to blocks 86 loose upon the shaft 79. The belts are pressed against the roll by weights 87 mounted on guides 88 on blocks 89 carried by the blocks 86. The weights are engaged by arms 96 on a rock-shaft 94 having arms 93 connected by links 90 to the blocks 89 so that as the blocks 89 move with the belts about the shaft 79, the weights are gradually moved along the guides 88, thereby automatically reducing the braking pressure. When the web has nearly expired, the weights have moved beyond the line joining the axes of the pulleys 78, 83 and the tension on the roll is removed. The guide roller 101 is adjustable and for this purpose is carried on an arm 102 of a rockshaft 103 provided with a hand-lever 106<1> locked in adjusted position by a bolt 106 and slot 105. The cable 36 for raising and lowering the blocks - 29 passes round a pulley operated by a chain or cable from a fluid pressure cylinder and, in the case of a press having a number of roll changing mechanisms, the pulleys of all the cables 36 are operated simultaneously by a single fluid-pressure cylinder. The opposite ends of the cables may be provided with hooks so that during the lowering of the blocks 29, new reserve rolls may be raised to the rails 4, the front ends 133 of the brackets 3 being adapted to yield in an upward direction to allow of vertical lifting of the new rolls.