| 摘要 |
417,443. Feeding webs. HOE & CO., Ltd., R., 109, Borough Road, London.-(Assignees of Tomlin, J. R., Lundquist, A., and Horton, A. J. ; 138th Street, New York, U.S.A.) Jan. 2, 1933, No. 67. Convention date, March 3, 1932. [Class 100 (i).] Web-renewing mechanism for printing-presses and other machines comprises a support for a running roll and a reserve roll, means positioned at the end of and rotatable with the reserve roll to hold the face end of the web to the body of the roll, means for rotating the reserve roll at web speed, a device for bringing the expiring web and the reserve roll into contact to join the webs together and means, actuated in dependence upon the angular position of the reserve roll, for operating the web-joining device, for causing the web-holding device to release the web, and for severing the expiring web. Figs. 1 and 2 show the position of the parts at the moment of making the join and Fig. 59 the position just prior to that time. The running roll 28 and reserve roll 29 are carried in supports constructed as described in Specification 417,499 and comprising cross-heads 11, 11<1> adjustably mounted on shafts 8, 81 secured to yokes 7, 7<1> having spindles 6, 61 rotatable in stands 5, 5<1>. The spindle 6 carries a gearwheel 16 adapted to be driven by an electric motor 22 to rotate the support to bring the rolls from loading position to the normal running position, which is that occupied by the roll 29. The end of the reserve roll is cut to V-form as shown in Fig. 2, and to the end are secured strips 26 extending beyond the ends of the roll and secured by clamps 202 to heads 201 which are fixed to arms 204 by means which permit adjustment of the heads in accordance with the diameter of the roll. Each arm 204 is fixed to a curved arm 226, Fig. 36, pivoted at 2261 in a casing 223 which is normally freely mounted on the roll-supporting spindle but which, during the renewing operation, is clutched to the spindle by a band 232 one end of which is secured to the casing and the other end to the arm 226 which is urged by a spring 239 to cause the band to grip the spindle. The unwinding of the running roll is controlled mainly by a brake on the roll spindle, but, in addition, the roll is engaged by belts 56, 561 normally driven by the roll to serve as brakes, but adapted to be driven positively to speed up the reserve roll to the speed of the expiring web. These belts pass round pulleys 62, 57 and spring-mounted pulleys 63 arranged in casings 61 and the pulleys 57 are loosely mounted upon a shaft 58 and adapted to be driven therefrom through a differential gear in a casing 59. The drive of the shaft 58 is effected through a second differential gear in a casing 69, Figs. 2 and 56. The shaft 277, Fig. 56, is driven continuously from the press by bevel gear 71 and drives the shaft 58 through bevel gears 281,276. Gear 281 is carried by a rotatable frame 283 provided with a gear 284 engaging a gear 285 to the shaft 286 of which is fixed a brake drum 287 encircled by a brake band 289, Fig. 2, which is applied by a spring and released by an electromagnet 293. This electromagnet is normally excited so that the shaft 58 is not driven by the differential, but when the reserve roll is brought into engagement with the belts, the magnet is de-energized. A dash pot is connected to the armature of the magnet so that the application of the brake, and thus the speeding up of the belts is effected gradually. This magnet is also in circuit with the main control switches of the press so that upon accelerating or slowing down the press, the magnet is de-energized and the belts driven to control the roll. The roll surfaces are engaged by fingers 23 secured to shafts 25 rotatable in the yokes 7, 7<1>. When a roll in normal running position is reduced to a certain diameter an arm on the shaft 25 of its finger closes a switch 102, Fig. 59, to start the motor 22 to rotate the roll support in a clockwise direction. Soon after the commencement of the rotation of the roll support, one of two cams 99 carried by the gear wheel 16 closes a switch 97 to start a motor 37, Figs. 2 and 59 which, through a crank 41 and spring rod 42, lowers a web deflector arm 34 from its normal position shown in broken lines in Fig. 1, to the position shown in Fig. 59 in which a brush 32 carried by the arm contacts with the running web but does not press it against the reserve roll. The arm is arrested in this position by the engagement with a projection 49, moving with the arm, of the armature 46 of a magnet 48 which is energized, upon the lowering of the arm 34, by the closure of a switch 53 controlled by a cam disc 52 on the shaft of the arm 34. When the arm 34 is lowered, a switch 54 is opened by the cam disc 52 to stop the motor 37. Soon after the closure of the switch 97 by the cam 99, a second cam 101 on the gear 16 closes a switch 98 which causes the de-energization of the brake magnet 293 to effect the driving of the belts 56, 56<1>. The clockwise movement of the roll support continues until an arm on the shaft 25 of the finger 23 engaging the reserve roll closes a pair of connected switches 83, 95 to stop the motor 22. The parts are now in the position shown in Fig. 59, the roll 29 being rotated by the belts and the arms 204 rotating with the roll. When the running roll 28 is still further reduced in diameter, an arm on the shaft 25 of its finger 23 closes a switch 103<1> in circuit with a timing device on the spindle of the reserve roll and with a relay which causes de-energization of the magnet 48. This timing device, which is shown diagrammatically in Fig. 59, comprises a contact segment 165 rotating with the roll spindle and a pair of brushes 178, 179 on the roll support. The relative position of the segment 165 and arms 204 is such that, when the brushes 178, 179 are connected by the segment, the end of the web, previously supplied with adhesive, has been carried beyond the point where the surface of the reserve roll is adjacent the running web. The de-energization of the magnet 48, consequent upon the closure of the circuit controlled by the timing device, releases its armature 46 and allows further movement of the arm 34 by the spring rod 42 to press the running web against the reserve roll, and to bring abutment members 322, Fig. 1, on the arm into the path of the heads 201. As the webs are united by the adhesive the engagement of the heads 201 with the abutments 322 actuates knives pivoted in the heads to sever the holding strips 26 to free the end of the web of the reserve roll. One of the abutments 322 is pivoted on the arm 34 and adapted, upon actuation by the head 201, to close a switch 329 thereby closing the circuit of a solenoid 123, Fig. 25, for actuating a severing device for the expiring web. The web-severing device comprises a wire 132, Fig. 25, normally housed in a slot in the shaft 8 or 8<1> and connected at one end to a pivoted arm 133 and at the other end to an arm 129 fixed to a shaft 127 which, when the solenoid is excited, is turned by the connections 125<1>, 126 to bring the wire 132 into the path of the running web and cause its severance. The closure of the switch 329 also causes the closure of circuits to drive the motor 37 in a direction to raise the arm 34 and to energize the brake magnet 293 so as to disconnect the drive to the belts 56, 56<1>. When the arm 34 is fully raised the switch 53 is opened.by the cam disc 52 to open the circuit of the motor 37. When the arms 204 are arrested by engagement with the abutments 322, the continued rotation of the roll causes relative movement of the arms and casings 223 releasing the clutch bands 232 and allowing the arms to fall by gravity into an inoperative position. Specifications 410,785 and 417,500 also are referred to. |
