Patent GB-505780-A (GB)
Title: Improvements in control means for web wrapping machines
IPC: D07B7/14
Filed: 1937-11-16
Abstract: 505,780. Web wrapping machines. SYNCRO MACHINE CO. Nov. 16, 1937, No. 31527. Convention date, Dec. 10, 1936. [Class 109] [Also in Group XVI] The serving head of a web wrapping machine is provided with a magnetic brake actuated by a known tensioning device when the tape or web fed from the cop spindle breaks. The serving head comprises a turn-table 65, the hub 66 of which is secured, by screws 67, a collar 64 and looking rings or nuts 63 to a spindle 62 to which is also attached-a motor. The turntable 65 also carries several guide spindles 84, the tops of which carry contacts 85 insulated therefrom and connected to a sector ring 87 mounted on a ring 88 insulated from the turntable 65. The web or tape in passing from-the cop around the guide to the wire &c., to be covered holds a lever or switch arm 89 out of engagement with the contact 85. The spindle 62 is provided with a reduced extension 68 on which is mounted the cop sleeve 69. Attached to the turntable 65 within the recess 74 is a flanged, slotted stator core 75 of magnetizable material and carrying a stator winding 77 for the tensioning and braking, one terminal 78 being connected to a ring 79 mounted on an insulating ring 80 fixed to the hub 66. The other terminal of the winding 77 is earthed through the frame of the machine. A brush completes the circuit to the ring 79. A magnetic rotor 82, notched to provide polepieces, is fixed to or formed by the flanged end of the cop sleeve 69. When the web or tape breaks the switch arm 89 makes contact at 85 and current flows from wire 27 through wire 32, winding 33 of a relay B, wire 34, and wire 36 to earth. This causes relay B to open the stop circuit of the machine by disconnecting wires 16 and 18. Thus a relay A is returned from operated position to the position shown in Fig. 8. With the relay in this position a circuit is completed from wire 27 through wire 37, movable contact 38 of a thermal relay C, wire 39, movable contact of relay A, and wire 40 to the winding 77. Through this circuit the winding 77 is energized with a larger current, since resistance 28 is not included in the circuit. The rotor 82 is thus attracted with sufficient forces to stop the sleeve and cop almost at once. The return of the relay A to normal position also completes a circuit to a heating coil 45 and the relay C viz. :-from-wire 16 to wire 41, capacity contact 5 of relay A, wire 42, resistance 44, heating coil 45, wire 46, movable contact 47 of relay C, wire 48 and wire 22. The coil 45 thus begins to heat up a, preferably, bimetallic arm 43. After a certain lapse of time, arm 43 is distorted sufficiently to close contacts 50, when current flows from wire 22 to wire 48, wire 49, contacts 50, arm 43, wire 51, winding 52, wire 42, movable contact 5 of relay A and by wire 41 to wire 16. Thus relay C is operated to break the circuits at 38 and 47 and to make a holding circuit for the winding 52 through contact 53, which holding circuit interconnects wires 48 and -51. The breaking of circuit by the movable contact 38 interrupts the supply of current, to coil 77. By this time, the cop sleeve has come to a stop and the circuit to the winding is broken to prevent overheating &c. The breaking of circuit at 47 stops the supply of current to heating coil 45 so that arm 43 begins to cool off, and when it opens the circuit at contacts 50, relay C is held closed by the holding circuit which is made by contact 53. Contact 38 breaks the circuit across the resistance so that the tape can be re-threaded.