Patent GB-950883-A (GB)
Title: Conveyor system
IPC: B65G47/51
Filed: 1961-06-21
Abstract: 950,883. Conveyers. BROOKHIRST IGRANIC Ltd. June 21, 1961 [June 21, 1960], No. 22424/61. Heading B8A. Articles such as letter trays awaiting conveyance to sorting stations in Post Office conveyer systems are diverted from a continuously running incoming conveyer (A, Fig. 1) to a first storage conveyer B. When the latter has received a predetermined number of articles, conveyer A is diverted to a second storage conveyer C and when this has received its predetermined number of articles conveyer A is diverted to a third storage conveyer D. Conveyer B discharges its articles to an outgoing conveyer E after which conveyers C and D are permitted to discharge their articles, in turn to conveyer E. There may be any desired number of storage conveyers. The circuitry is arranged so that on the resumption of power after an electric powerfailure, the articles continue to be dealt with in the correct sequence. In operation, the supply of articles from the conveyer A to the storage conveyers B, C, D, is controlled by a circuit 20 (Fig. 2a), when power is switched on and applied to lines L1, L2, and L3, and relay 36 closes contacts 36a, 36b. When the first article on conveyer A passes over a switch LS1, contacts 1 and 2 (Fig. 2a) are respectively closed and opened so as to energize a relay 34 which opens switch 34a and closes switch 34b. The former energizes a stop 2 which momentarily arrests and thus spaces the next following article. The switch 34b energizes the winding 52c of a rotating stepping switch 52. Each time relay 34 is energized, an adding coil 30a of a counter 30 is energized so as to indicate the entry of an article to the storage conveyers. When the article passes LS1, contact 1 opens and relay 34 de-energizes, and a spring retracts the armature of winding 52c to rotate the stepping switch 52 from position 0 to position 1. This procedure repeats until all the predetermined (determined by the number of positions 1, 2, 3... available on the rotor of stepping switch 52) number of articles have passed on to storage conveyer B. The rotating contact 52d of switch 52 now engages a recycling contact N which thus energizes a relay 54 thereby closing and opening switch 54b and 54a, respectively. Switch 54b energizes the winding 38c of a rotary stepping switch 38 which has positions 1, 2, 3... corresponding to the number of storage conveyers and a recycling position X. Switch 38 is moved from position 1 to position 2 by spacing action when winding 38c is de-energized resulting from stepping switch 52 moving from position N to position 0. The latter occurs with a time delay due to action of a delayed action relay 56 energized consequent to the closing of relay 54. Closing of switch 54b also energizes the adding winding 48b of a counter 48 which controls the energization of a lamp 50 which indicates when the storage area is full. The movement of stepping switch 38 to position 2, de-energizes a relay 40 in the circuit of motor M1, driving conveyer B, and sets an article diverting mechanism 4 to neutral position. Similarly relay 42 in the circuit of motor M2 of storage conveyer C sets an article diverting mechanism 6 to divert articles from the conveyer A to the conveyer C. When all the storage conveyers are filled as above described, a cam 48d of the counter 48 engages a member Y to operate switches 48e, 48f. These operate the articles stop 2 (to prevent further movement of articles beyond stop 2 on the conveyer A) and the indicator lamp 50, respectively. The supply of articles from the conveyers B, C, and D to the conveyer E is controlled by a circuit 22 (Fig. 2b). Provided no articles are stationary on a switch 5 to maintain the latter open (due to a predetermined number of articles being backed up against a limit switch 16) and before any previous discharge from any of the storage conveyers has commenced, a circuit is completed by the rotor of a switch 64 through a relay 66. The latter when energized retracts a stop 66 and closes a switch 66a in the circuit of the motor M1 of the storage conveyer B. Articles proceeding on the conveyer B thus proceed to switch LS2 and by similar circuitry to that described in respect of LS1 cause a rotary switch 76 to step round for each article discharged to the conveyer E. Similarly a subtract coil 30b of the indicator 30 is operated. Switch 64 is stepped round as each storage conveyer is emptied of its predetermined number of articles. When one storage conveyer has emptied, the stepping switch 76 through its contact N, relay 78, and contacts 78a, 78c, 78b energizes subtract coil 48c of counter 48. If the storage conveyers have all been supplied, cam 48d will now be in a position on one subtract movement of counter 48 to open switches 48e and 48f to extinguish lamp 50 and re-open stop 2. A delay circuit R, C prevents switch 74 from being operated by articles merely passing over the switch LS5. The arrangement of switch LS1 and relay 36 prevents a false count occurring on a resumption of power, following a power failure, by an article which has come to rest on switch LS1. The relay 34 and counter 30 cannot be energized until the article has moved out of engagement with the switch LS1. A similar arrangement exists in respect of switches LS2; LS3; and LS4; in relation to relay 36, to prevent a tray resting on any of these switches during a power failure, causing a miscount.