GB754035A - Improvements in or relating to remote control edge alignment device - Google Patents

Abstract

754,035. Automatic control systems for straightening webs. WEBER & CO., Inc., H. G. June 4, 1954, No. 16610/54. Class 38 (4). [Also in Group XVI] The side-ways deviations of a travelling web are sensed by a pneumatic device which controls an aligning mechanism at intervals determined by a footage control device so that the result of correction is evaluated before further correction occurs. The edge of a moving web 12, Fig. 2, is positioned over an aperture 55, Fig. 4, or apertures 28, 29, Fig. 3, in a tube 25 connected to a source of gas under pressure, so that the sideways variation of the position of the web is detected by the pressure in tube 25. Air under slight pressure is fed to tube 25 over pressurereducing valves 36, 37 and bleeder valve 41, and the pressure actuates one or other of switches 50, 51 according as the web moves to one side or other; in the central, or correct position, neither switch is closed. Switches 50, 51 close circuits to actuate motor 67, Fig. 1, in the appropriate direction and thus shift roll 11 laterally; motor 67 is operated for a predetermined time at pre-determined intervals. Motor control system.-A footage control switch 65, Figs. 2, 5, is actuated periodically in accordance with the length of web passing and momentarily short-circuits condenser 115 to discharge it quickly over resistance 143; valve 90 thereupon conducts upon the positive halfcycles of the supply voltage 92, 93 to actuate relay 102; during the negative half-cycles condenser 115 is charged over lines 109, 110, 111, condenser 115, resistances 117, 118, rectifier 119 and resistance 104, line 103, switch 98; the charge on condenser 115 is thus incrementally increased until it inhibits current through valve 100 and relay 102 is de-energized. Switch 98 is closed whenever motor 17, Fig. 2, is driving roll 16. Relay 102 thus closes contact 125 for a predetermined time at intervals determined by the setting of switch 65, and relays 150, 151 are actuated to close contacts 161, 162 to complete a circuit to determine the direction of energization of motor 67 in accordance with the actuation of switches 50, 51. As shown, switch 50 is closed, and a circuit is completed over switch 50, contacts 161, selector switch 175, relay 189, which actuates to operate contacts 203, 204 and drive motor 67 in one direction. If switch 51 were closed, relay 225 would be actuated to drive the motor in the reverse direction. If neither switch 50, 51 is actuated, the motor is not driven. In Fig. 6, not shown, a circuit is disclosed in which five webs from eight unwind reels are aligned. A single footage control switch and timing circuit is used, but each web has its own lateral detector controlling its own motor over a selective circuit.