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416,066. Feeding webs. SCOTT, D. J., 1032, Evergreen Avenue, Plainfield, New Jersey, U.S.A. Feb. 8, 1933, No. 3916. [Class 100 (i).] In a web-renewing mechanism for a printing or other machine, the joining of the webs is effected, without placing undue tension on the web, by bringing the reserve roll into contact with the running web and pressing the latter against a backing member which is driven at a higher speed than that of the web but is capable of being retarded by the pressure. Improved means for cutting off the old web and for braking the roll-supporting spindles are provided. The running roll 20, Fig. 2, and two reserve rolls 21, 22 are mounted on spindles 38, Fig. 13, carried in spider frames 25 fixed to a shaft 27 which is supported in standards and adapted to be driven by a reversible electric motor 28 through gears 29, 30, worm 32, worm-wheel 33, pinion 35, and gear 36 fixed to shaft 27. A set of tapes 63 pass round pulleys carried by a frame 64 pivotally mounted upon a shaft 64<a> and adjustably held by a device 64<a> so that the tapes are normally clear of the running web 23, but serve as a supporting backing for that web when the shaft 27 is rotated to press the roll 21 against the web to effect the join. The tapes are driven at a speed higher than the web speed by one or more electric motors 65 mounted on the frame 64, but during the renewing operation the tapes slip either on the surface of the web or on the pulleys round which they pass. The spindle 38 at one end of each roll is provided with a brake comprising a brake drum 39, Figs. 6 and 13, having non-radial cooling fins 41 and a pair of brake shoes 40 pivotally connected, one directly and the other through a lever 44, with an actuating arm 42 bearing against a roller 48 carried by a lever 49, the opposite end of which carries a roller 50 adapted , when the roll is in running position, to engage a cam 51. This cam is carried by a pair of levers 52, connected together by a link 55, one of the levers being connected by a link 56 to a pivoted arm carrying a roller 57, Fig. 2, resting upon the web. Thus, as the tension of the web increases or decreases, the roller 57 rises or falls, causing an adjustment of the position of the cam 51 to decrease or increase the pressure of the brake shoes on the brake drum. After the new roll is secured to the running web, the latter is severed by a knife 71, Fig. 9, normally housed in a tubular container 70 fixed to a pair of arms 69, Fig. 6, secured to the shaft 27. The knife is adapted, upon the excitation of an electromagnet 77, to be projected radially through a slot in the container into engagement with the web. The knife is fixed to a bar 72 having slots 73 engaging pins 74 fixed to the container, whereby the knife is moved radially by an endwise movement of the bar. This movement is effected in one direction by a spring and in the other by means of a bell crank lever, one arm of which is pivoted to the bar and the other arm of which is adapted to be actuated by the armature of the magnet 77. The circuit of each magnet includes a continuous contact ring 84, Figs. 2 and 13, fixed to the gear 36 and one segment of a three part ring 85 concentric with the ring 84. Current is supplied to the rings through brushes 88, 89 carried by a spring-urged bellcrank lever 90. Axial adjustment of the shaft 27 may be effected by a reversible motor 93, Fig. 13, which drives, through gears 94, 95, 96, a worm 97 engaging a worm-wheel 98 integral with a nut engaging a screw 101 engaging the end of the shaft 27. The nut is held against axial movement. The electrical equipment is shown in Fig. 17. The motor 28 may be driven in either direction at any time by closing one or other of the switches 103, 118, thus energizing one of the relays 109, 120 to close switches 111, 112, 122, 123 in the circuits to the motors. When the roll is in running position a cam disc 68 on the shaft 27 opens a limit switch 67 in a circuit containing a normally open switch 127, a normally closed switch 132, and a switch 129 which is held open by a press-driven governor 153 when the press is running above a certain predetermined speed. When the join is to be effected, the motor 28 is turned, by closing the switch 103, sufficiently to allow the switch 67 to close, and the press is slowed down sufficiently to allow the switch 129 to close, this being indicated by a lamp 155, the circuit of which is completed by the wire 105 from the main 104, switch 129, and wires 156, 157 to main 110. The switch 127 is now closed, completing a circuit through a relay 135 which closes switch contacts 137, 138, 139. The contact 137 completes a maintaining circuit for the relay 135, and the contact 138 closes a circuit through the relay 109 to start the motor 28. When the join is effected, a switch 143 is closed to complete a circuit through a relay 146 which, by closing the switch 149, completes a circuit through the solenoid 77 to sever the old web. When the roll reaches the running position the circuits are again broken by the opening of the limit switch 67. The switch 132 allows of interrupting the renewing operation if desired.
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