| 摘要 |
616,162. Feeding webs. HOE & CO., Ltd., R. Nov. 22, 1945, No. 31537. Convention date, Nov. 22, 1944. [Class 100(i)] In a web-supply mechanism for a printing or other machine comprising a rollsupport for moving a web-roll from a loading position to splicing, feeding and expiring positions, and web-tension control mechanisms applicable (1) to the peripheral surface of the roll when in feeding position, and (2) to the core of the roll from the feed position to the expiring position, the mechanisms are regulated in response to the tension of the web as it passes from the roll, and the web-tension control is transferred from the first mechanism to the second mechanism such that as the one decreases the other increases its control effect. As shown in Figs. 1, 4 and 5, a spider 13 having three arms 17 carrying rolls 18, 19, 21, carries a worm wheel 129 by which it can be rotated from a motor 16. The web 22 running from the roll 21 passes over two spring-held floating rollers 76, 37 arranged, when the tension in the web increases or decreases, to operate switches 75, 44 or 74, 43. The switches 45, 44 control through an impulse switch, a motor 32 driving a gear sector 36 fixed to a shaft 29 carrying arms 31. Tensioning belts 23 driven at a speed slightly lower than that of the web 22 pass around pulleys 24, 25 which are not movable axially and pulleys 26 mounted at the ends of the arms 31. Fig. 5 shows the spider positioned for splicing the replacement roll 19 to the web from the old roll 21, but in the normal running position the roll from which the web runs is positioned to be tensioned by the belts 23. When the running roll 21 is in the position shown in Fig. 5, the web 22 is tensioned by an auxiliary brake 77 controlled by the floating roller 76 and the switches 74, 75 which control, through the impulse switch, a motor 64. A sprocket wheel 54 freely rotatable on the spindle 14 of the spider 13 and driven from the motor 64 through a sprocket 68 and a wheel 67, carries a cam 53 whose height increases progressively from the portion 69 to the portion 71. A cam 61 on the sprocket wheel 54 is adapted to operate a limit switch 60 carried by a ring 55 loosely mounted on the spindle 14 and held stationary by washers 56 and by links 58 attached to the frame of the machine. The spindle of each roll carries a brake wheel 80 round which passes a brake band 77b having one end fixed to an extension 78 of a lever 79 pivoted at 84 and urged in a clockwise direction by a spring 89. A rod 86 pivoted at 88 to the lever 79 has a hollow end which receives a rod 96, both rods 86, 96 having collars against which a spring 95 bears. The other end of the rod 96 is adjustably secured to an arm 98 pivoted at 101 and formed integral with an arm 102 carrying a roller 103 adapted to engage the cam 53. The other end of the brake band 77b is adjustably connected to a pair of links 81 pivoted to a bifurcated handle 100 which is also pivoted to an extension 85 of the lever 79. When the handle 100 is moved to the left in Fig. 4, the brake is completely released. the splicing device 104 comprises a brush 108 carried by a pair of arms 105 and a knife 109 carried by a pair of arms 106. The arms 105, 106 are pivoted at 107 and one of the arms 106 carries a latch 112 engaging a pin 113 on one of the arms 105 to hold the arms together normally, a solenoid 115 releasing the latch when energized. An extension 118 of a handle 116 pivoted at 117 carries a chain 119 connected to one of the arms 105. When the arms 105, 106 are lowered to the splicing position shown in dotted lines in Fig. 5, the chain 119 allows the handle 116 to fall to the upper of the two positions shown in dotted lines in Fig. 5, and cams 121 and 125 on the handle 116 and the pivot 107 operate switches 122, 126, 127. When the web 22 runs from the roll 21 in the normal running position, the tension is provided by the belts 23 and is regulated by the floating roller 37. When the roll nears exhaustion, the handle 100 on the roll 21 is moved to the right in Fig. 4 to apply the cam-operated brake 77, the cam having been reset to present its lowest portion 69 to the roller 103 of the roll 21. A press button switch is then closed manually which starts the motor'32 to raise the arms 31 and remove the belts 23 from the roll. and allows the switches 74, 75 to control the motor 64 and rotate the cam 531 to apply the brake 77. The speeds of the motors 32, 64 are synchronized so that the rate at which the brake 77 is applied is substantially equal to the rate at which the braking effect of the belts 23 is removed. When the arms 31 have been fully raised, a cam 30 opens a switch 40 to stop the motor 32 and start the motor 16 to rotate the spider 13. One of three cams 220 on the spider operates a switch 210 to stop the spider in the splicing position. The splicing device 104 is now manually lowered to its open position and the handle 116 falls to the upper dotted line position of Fig. 5. This opens the switches 122, 126, 127 interrupting the circuit to the motor 16 and also preventing certain automatic operation of the motors 32, 64. A push button switch is closed maually to lower the arms 31 on to the roll 19 to rotate it at substantially running web speed. A lever 51 opens a switch 49 to stop the motor 32 if the belts are lowered too far. The handle 116 is then pulled down to the lower dotted line positioning of Fig. 5 causing a cam 123 to close a switch 124. A cam 136 on the spindle of the roll 19 oscillates a rod 135 continuously while the roll is rotating which opens and closes a timer switch 59. The first time the timer switch is closed after the switch 124 has been closed, the solenoid 115 is energized to open the latch 112 and release the brush 108 which presses the web 22 against the new roll 19. The next time the timer switch 59 is closed, the knife 109 is released to sever the web from the roll 21. The splicing device 104 is now raised manually and the switches 122, 124, 126, 127 return to their normal positions. Closing the switch 126 causes the motor 64 to rotate the cam 53 back to its reset position in which the motor is stopped by the cam 61 engaging the limit switch 60. Closing the switch 127 allows the floating roller 37 to take control of the tension belts 23. The spider 13 is rotated to its normal running position by manual depression of a switch. The electrical circuit is given in Fig. 6 (not shown). In a modification, means for manually operating the brake 77 are provided. The righthand end of the lever 79 has an extension through which passes a threaded stud fixed to the arm 17 and carrying a knurled adjusting nut which bears on the extension and applies the brake when it is tightened. The arms 98a, 102a, Fig. 12, corresponding to arms 98, 102, are not formed integral at 101 but are each pivoted on a bolt 101a provided with a hand nut 239, the arm 102a having teeth 242 adapted to engage recesses 243 in the arm 98a, and the arms being separated by a spring 241. When the nut 239 is tightened, the arms are clamped together, but when the nut is loosened, movement of the arm 102a by the cam 53 is not transmitted through the arm 98a to the brake. Specifications 453,046, 478,578 and 502,400 are referred to. |
