Patent GB-190926918-A (GB)
Title: Improvements relating to Printing Presses.
Inventor: LAKE WILLIAM EDWARD
IPC: B65H23/06
Filed: 1909-11-19
Granted: 1910-11-21
Abstract: 26,918. Lake, W. E., [Goss Printing Press Co.]. Nov. 19. Feeding webs. - A braking-device for acting on the roll-spindle of a rotary printing-machine of the kind in which the brake is actuated by pneumatic means controlled by the tension of the web to maintain the tension constant, is constructed with means for automatically increasing or relieving the pneumatic pressure of the brake-controlling devices, and in the case of a breakage of the web, the pressure is increased quickly so as to stop the run of the web. As shown, the web-roll is mounted on a spindle 10 fitted with a brake-pulley 12 formed with V-shaped edges adapted to be engaged by similarly - shaped blocks 15, 16 carried by levers 13, 14 mounted on pivots which can be adjusted laterally on a hand-operated screw 17 when the roll is to be adjusted laterally. The levers 13, 14 are pivoted to a piston-rod 24 and to a cylinder 22, in which a piston 23 fits tightly, and the levers are moved apart to cause the blocks 15 16 to brake the pulley 12 by admitting air under pressure to the lower side of the cylinder 22. In the normal running of the press, air is admitted to the cylinder 22 from a supply pipe 42 through valves 43, 59, Fig. 1, the valve 43 being set by a hand-lever 46, secured in position by the engagement of a pin in one of a series of holes 92. The plug 45, Fig. 7, of the valve is then set so that openings 47, 54, 53, 49 register in part, and a pipe 56 connected to the top of the cylinder 22 is connected to the atmosphere by ports 48, 55, 50. Air passes from the pipe 57 through the valve 59, which is arranged, as shown in Fig. 5, with the ports 61, 66, 62, 67 in partial register, and the extent of the register of these ports is controlled by the tension of the web acting through a spring-raised roll 32, which is connected by a slotted lever 38 to an adjustable rod 72 connected to an arm 71 on the plug of valve 59. The valves 59, 43 are connected to the cylinder 22 by means of flexible pipes, and in the pipe 71<Î> from the valve 59 to the cylinder 22 is arranged a pressure gauge 75 and a valve 77, which is automatically opened by an adjustable spring 81 when permitted by a lever 82 controlled by a cam 84 on the valve 59. The valve 77 opens when the pressure in the pipe 71 x reaches a certain amount, and this valve thus controls the pressure in the lower half of the cylinder. This valve opens to relieve the pressure in the cylinder 22, when the tension of the web has increased, owing to the raising of the arm 71 and clockwise rotating of the valve 59 and cam 84. The braking pressure is thereby lessened, and the tension of the web decreased. The increased tension of the web also closes partially the valves 43, 59. If the tension of the web decreases the braking pressure is increased. The plug of the valve 59 is fitted with a piston 68, Fig. 6, which is adjustable by a nut 70 which engages a threaded spindle 69. In case of a breakage in the web, the roll 32 rises quickly and raises the left hand end of the lever 38. This causes a segment 41 on the lever to move clear of a stud 89 on one arm of a spring-controlled bell-crank lever 87<a> and this lever moves to the right, and a hooked-end 88 ot its other arm 87<a> engages a stud 86 on an arm 85 of the valve 43, and the valve is moved so as first to cause more air to pass into the pipe 57. The valve 59 is also opened more fully by the depression of the rod 72, and the cam 84 is moved so as to hold the valve 77 closed. The air pressure in cylinder 22 is quickly increased, causing the roll to be stopped. When the roll is stopped, the bellcrank lever rotates the valve 43 still further so as to cut off the air supply to the valve 59, and the valve 43 is held in this position. The braking- mechanism may be put out of action by swinging the lever 46 to the left, and thereby connecting the air supply to the top of cylinder 22 above the piston, and in this case air can escape from the lower part of the piston by way of the valve 59 and outlet 50 in the valve 43. The brake may be operated by a hand-wheel 25 provided with a nut which engages a threaded part of the piston spindle, a removable sleeve 26 being fitted between the top of the cylinder and the nut, when the brake is to be adjusted.