GB749833A - Method of and apparatus for indicating, or actuating a control device in consequence of, a breakage in materials of low electrical conductivity such as textiles - Google Patents

Abstract

749,833. Signals and stop-motions in textile spinning &c. machines. BREUNING, E. Feb. 27, 1953 [Oct. 17, 1952], No. 5589/53. Classes 120 (2) and 120 (3). In a method of indicating or actuating a control device, e.g. an automatic stop-motion, consequent on breakage of a thread or roving during a textile process, e.g. spinning yarns, the broken material contacts and thereby modifies the electric potential of a testing electrode which acts in conjunction with a charged electrode on an indicating and/or control means to which it is connected; the testing electrode is not connected to earth and normally has no voltage applied thereto. As shown in Fig. 1, the pipe-line 1 of a thread suction device houses a charged electrode 2 and a testing electrode 3 which is connected to the grid of a thermionic valve 4; when a broken end contacts the electrodes 2 and 3 the potential of the latter and hence of the grid is altered so that, given suitable adjustment of the grid bias by means of a resistance 5, the anode current of the valve 4 is varied, and such variation may be used to initiate operation of a stop-motion. The electrodes may be constructed as rakes, Fig. 2 (not shown), which make operating, albeit momentary, contact with all pieces of broken material passing through the pipe. In the arrangement of Fig. 3, an alternating voltage from a transformer 6 is applied to the electrode 2, and the electrode 3 is connected to the high resistance control input of an alternating current amplifier; the electrodes are surrounded by earthed protective rings 11 and 12 of conducting material, and the effects of inadequate insulation or capacitance therebetween are reduced by a condenser 9; a rectifier 13, with signalling and controlling devices 14 and 15, is connected to the output of the amplifier 10 and controls a stop-motion (not shown). The embodiment of Fig. 4 comprises a double triode 16 with one cathode, one triode system operating as a rectifier while the other determines the magnitude of a compensating current for a polarized relay 17; a normal balance of anode currents is upset when the potential of the grid of the rectifier system changes (as a result of the breakage, as before), and the relay acting through a relay 18, operates a signal and control device to release another relay which arrests the drive for the thread or roving, through an auxiliary contact 19 of relay 18, the anode current of the second triode system is reduced, the armature of the relay 17 therefore reverses after an adjustable predetermined time interval and resets the circuit arrangement so that the drive may continue. A single apparatus as described may be connected to several input stages of a textile machine.