Patent GB-191117980-A (GB)
Title: Improvements in Tension Apparatus for Paper and like Rolls.
Inventor: WILLIAMSON GLENN SYLVESTER
IPC: B65H23/18
Filed: 1911-08-08
Granted: 1912-08-22
Abstract: 17,980. Williamson, G. S., and Mandelick, C. E. Aug. 8. Feecding webs.-Relates to means for braking the roll from which the web is passing to a printing-press &c., and consists in the provision of an electric generator driven from the roll spindle, whereby: (1) the braking effort increases until the web has attained its maximum speed and then is gradually reduced as the speed of the web roll increases, due to its lessening diameter; (2) the rotation of the roll is arrested when the press is stopped by either the ordinary or the emergency switch; (3) in the event of the stoppage of the press with a roll only partly used, the brake effort is prevented from increasing to its maximum; and (4) the press is stopped as soon as the spindle attains a certain angular velocity due to the exhaustion of the roll. Means are also provided for axially adjusting the roll to keep the web running true. (1) The spindle 3 of the roll 4 carries at its end a conical soft-iron clutch member 13, adapted to engage a magnetic member 14 on a shaft 15, which is connected to the armature of the dynamo by gearing 30, 31. The dynamo and its driving-gear are mounted on a bracket 8, which is pivoted at 10 to the press frame 1. The shaft 15 rotates bearings 16, and is feathered within a sleeve 17 mounted in bearings 18. The sleeve 17 carries a flange 17<a> which is connected by two universal joints 20, 21 to the clutch member 14. The flange 17<a> and the clutch member 14 are furnished with spherical sections 22, over which a spring telescopic casing 22<a> is placed, forming a chamber which may be filled with grease. The bracket 8, when swung into position against the press frame, can be locked by a lever 32, which carries a lug 33 adapted to engage a lug 34 on the press. Movement of the lever 32 to unlock the bracket also breaks the clutch circuit. The field-magnet frame 36 of the generator is mounted on ball bearings and is normally held in position by an arm carrying an adjustable weight which, acting through a cord and a fusee, offers a decreasing resistance to movement as the displacement increases. The magnets are excited by a series winding and one 47<a> from an outside source. The field frame carries a gear 43 driving a pinion 44 on the shaft of a rheostat 45, so that as the field frame moves by the torque of the armature, resistance is switched into the armature circuit. When the roll commences to turn, no resistance is in circuit, so that the brake effort increases until the press reaches its full speed. As the angular velocity of the roll increases owing to its lessening diameter, the field frame moves, and switches into the circuit resistances of increasing magnitude, thus progressively decreasing the brake effort. (2) Should the press be stopped during a run by the emergency switch, the brake effort is increased by cutting the resistance out of the armature circuit. On operation of the switch, a solenoid 55, Fig. 9, is excited, causing the switch 56 to connect the terminals 57, 58, and thus short-circuit the rheostat. Simultaneously, the winding 96 of the magnet 87 is excited, causing the armature 89 to close the switch 92, 93 and excite the coils 82 of a magnetic friction brake 81. This brake comprises a member secured to the main frame, which cooperates with an iron disk armature 84, sliding axially in the generator pinion 31. A spring plunger 86 separates the members when the circuit is broken. On stopping the press by the ordinary stopping-switch, the winding 97 is excited and the switch 92, 93 closed as before. The generator circuit is employed for exciting the brake 81, but since the emergency switch first cuts out the resistance, a much stronger current is obtained than when the ordinary switch is employed. Operation of the emergency switch short-circuits the driving-motor of the press, while the ordinary switch cuts resistance into the armature circuit and finally breaks it. (3) In the event of a stoppage of the press in the middle of a roll, the braking-effort is prevented from increasing to its ordinary starting- value, and consequently breaking the web, by holding the generator field in the position corresponding to the temporary size of the roll. The core of the solenoid 55 in ascending rocks a latch 62 into engagement with the spur-wheel 43 on the field-magnet frame. A spring is interposed to prevent breakage. A device is also provided for locking the field frame of the generator as soon as the roll reaches a predetermined angular velocity. A disk on one end of the frame carries a stud which engages a spring latch on a vertically movable spring rod connected to the lever 32 for locking the frame 8 in position. Operation of the lever 32 to insert a new roll unlocks the field-frame and returns it to its normal position. (4) When the spindle attains a speed corresponding to a nearly-exhausted roll, the emergency switch of the press is operated by a governing-switch 203 on the end of the shaft 15. This comprises a casing in which two segments 201, held together by a spring 202, are pivoted. As the speed increases, the segments 201 grip and rotate the casing, which then operates a sliding contact 204 and inserts a conducting-part between the terminals 205, 206. A spring 207 returns the parts. In order to adjust the roll laterally, the shaft 17 is adapted to be moved by a lever 123 pivoted at 125 and connected at the other end to a nut on a screw 127. This screw carries a bevel-wheel 129 which can be rotated by a wheel 130 and hand - wheel 132, or by a wheel 131 driven through worm gearing 134, 135 from a reversible motor 133. The worm-wheel 135 is held on its shaft by friction to allow slipping when the hand-wheel 132 is actuated.