GB896687A - Improvements in and relating to means for detecting signalling faults for the control of strip material - Google Patents

Abstract

896,687. Photo-electric flaw-detection and sheet sorting. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Nov. 25, 1960 [Nov. 27, 1959], No. 40460/59. Class 40(3). An arrangement for initiating a controlled action in response to detected faults of travelling strip material after the faults have travelled a given distance, comprises a fault detector, a distributer, a generator producing signals which represent the progress of strip travel, a number of electronic gates and an equal number of integrating delay means, each associated with one of the gates, the distributer being connected to the output of the fault detector and the several gates being connected to the generator and to the several outputs of the distributer so that the several gates are successively controlled by the successive signals from the distributer, each to pass the signals from the generator to the associated integrating circuit for integration so that the output signals from the several integrators indicate successively detected faults after a delay period defined by the travel of the strip from the point of fault detection to a point where the controlled action has to be effected. The sheet ST of strip material is fed from a roll 1 through a fault-detector 2, which may be of the photoelectric type, producing, when a hole is detected, a pulse which is applied to terminals a, f of a selector DS, preferably a decade counter, having five pairs of electrodes a, f, b, g . . . e, j capable of detecting a total of five faults between the detector 2 and a device 3 for cutting the strip ST into sheets of a predetermined length. Synchronizing pulses are continuously produced at short intervals by an impulse generator SG triggered by a contact roller CR operated from the strip ST and are passed to gates 13.1 ... 13.5 linked to the five pairs of electrodes a, f; b, g; . . . e, j. A fault-indicating pulse applied, for example, to the electrode terminals a, f opens the gate 13.1 to allow a pulse to pass from SG to the integrating circuit 11.1, which, after measuring a predetermined time interval, operates a resetting circuit RS1 to restore the gating circuit 13.1 and the integrating circuit 11.1, and also to pass a pulse to a combinator circuit CO which is conjointly operated by a pulse produced at contacts CC operated by the cutter to pass a pulse over an output CL controlling a sorting mechanism to divert the cut sheet in which a hole has been detected. When a fault-indicating pulse has been applied to the terminals a, f, the selector DS is stepped so that the next pulse from the detector 2 is applied to terminals b, g so that the gate 13.2 is opened to allow pulses from SG to pass to the integrating circuit 11.2 to measure the predetermined time interval at the end of which reset circuit RS2 is operated. When the selector DS has been stepped so that the terminals e, j are operative, the pulse from circuit RS5, in addition to resetting the circuits 11.5 and 13.5, also restores the selector DS to the condition in which the next fault impulse is applied to the electrodes a, f.