Patent GB-968596-A (GB)
Title: Monitoring arrangement for item conveyor systems
IPC: G06K13/067
Filed: 1960-12-16
Abstract: 968.596. Conveving systems. BURROUGHS CORPORATION. Dec. 16, 1960 [Dec. 24, 1959], No. 43441/60. Heading B8A. [Also in Division G4] Articles in a conveying system are monitored by a series of detectors each supplying a pulse when an article or a part of an article passes it, the pulse from the first detector being supplied to delay means to give a delayed signal which is compared in time with the undelayed signal from the next detector in the series, and so on, there being means whereby in the event of a difference in timing of the compared signals being greater than a predetermined amount in a predetermined sense an alarm is operated or/and the system is switched off. As applied to the feeding of bank checks in a sorting machine of the kind having a guideway along which are disposed pairs of driven gripping rollers and direction changing rollers 31, the checks are supplied one by one from a hopper 13 by an endless driven belt 17 and are moved along the guideway past a series of photo-electric devices BOL-a to BOL-g, a magnetizing head to produce magnetic marks on the checks and a read head 33 to read these marks. A batch printer prints further information on the checks before they reach the deflecting blades which sort them according to information obtained by the read head. As the checks pass the various detectors a pulse is transmitted when the leading and trailing edges of each check pass each detector, these pulses being shown respectively in Fig. 2 as trailing edge pulses Ta to Tg and leading edge pulses Lb to Lg, some of the pulses not being used. In addition, a feeder clutch signal 35 provides a pulse when each check commences to move into the guideway, i.e. as the belt 17 is started for each check. A standby station 284 is provided at which checks may be stopped if desired. Whenever this station is out of use a further pulse is injected into the system at a number of positions labelled " not demand " (Figs. 3A, 3B, not shown). In the simplified circuit of Fig. 2 each pulse is simultaneously fed to a delay means 43, 57, 71, 81 or 93 &c. and to a flip-flop 41, 55, 73, 83 or 91 &c. so as to set the latter. In its set condition each flip-flop supplies a pulse to a corresponding coincidence device in the form of an " AND " gate 45, 59, 75, 85 or 95 &c. The delayed pulse is also fed to the corresponding coincidence device. Each coincidence device is normally prevented from being fully conditioned by also supplying each pulse except the feeder clutch signal to the flip-flop associated with the preceding pulse circuit in such a way as to reset it before the delayed pulse in the preceding circuit reaches the coincidence device, i.e. the pulse from Ta resets flip-flop 41 before the delayed feeder clutch signal pulse from delay means 43 reaches coincidence device 45, and so on throughout the system. At the position of the device BOL-d both leading and trailing edge pulses are fed into the system and compared so that subsequent monitoring is by leading edge pulses only instead of trailing edge only. This enables a final comparison of leading and trailing edge pulses to be made at station BOL-g. Whenever a check is jammed or slowed in its travel between two monitoring points one of the coincidence devices will be fully conditioned before the corresponding flip-flop has been reset, resulting in a signal on one of the lines 47, 61, 77, 87, 97 &c. to a warning device and/or a device for stopping the conveyer system, e.g. by de-energizing the motors 25, 27, 29. A number of elaborations are shown in the more detailed circuit of Figs. 3A, 3B (not shown), these including the addition of pulse standardizers, inverters, feedback circuits, and provision for injecting further controlling pulses manually, e.g. an eject signal when a check temporarily held up at station 284 is to be released. Transistor circuits (Figs. 4A, 4B, 5A. not shown) are also described for performing the functions of delay means, pulse standardizer and photo-electric pulse producing means. Specifications 888,718, 926,247 and 968,595 are referred to.