Patent GB-1334175-A (GB)
Title: Control systems for conveyor installations
IPC: B65G51/46
Filed: 1971-06-10
Abstract: 1334175 Conveyer systems SIEMENS AG 10 June 1971 [11 June 1970] 19854/71 Heading B8A [Also in Division G4] In a conveyer control system, stations adapted to act on conveyer receptacles send operating and destination signals via peripheral control units individual to the stations to a programme control unit in order to compute the conveyer path sections which are to be prepared for the conveyer receptacles between the transmitting station determined from an operating signal and the receiving station determined from a destination signal, and in order to test the traffic condition of the conveyer system within the computed path sections, switching and control signals obtained from this computing and testing are transmitted to the peripheral control units. In a pneumatic shuttle-conveying system, a number of transmitting tubes communicate via a central switching station with a number of receiving tubes. Each transmitting tube starts with a compressed-air-blower station, has a number of transmitting stations spaced along it, and ends with a queuing zone station next to the central switching station. Each receiving tube has a number of receiving stations and ends with a suction-blower station. Information can be read from the conveyer receptacles automatically, or entered manually, at certain stations. Fig. 4 shows a system for use when the receptacles carry no identification marker and no destination marker. When a station wishes to insert a receptacle into the conveyer system, the corresponding peripheral control unit PS1, PS2 ... &c. provides a signal on a respective line Al1, Al2 ... which is hunted by a sampling device AE which, on detecting it, sends an acknowledge signal to the peripheral control unit causing it to connect itself to common lines NS1. Destination data (if present) on these lines from the peripheral control unit will be detected by a test and switch arrangement PEE, caused to connect itself to the lines by the sampling device AE. The destination data is supplied to the input register ES of an associative store AKS, together with incrementing of a counter Z, the incremented count and the identity of the peripheral control unit also being supplied to the input register ES. Each word of the store AKS can hold destination data, a control unit identifier and a count. The current control unit identifier from the sampling device AE is supplied to a comparator VE and all the words in store AKS are read out in turn via an output register AS. Those with the same control unit identifier as supplied from AE are treated as follows. The first is stored at ZSV, each subsequent one replacing that stored at ZSV if the latter has a higher count, so that ZSV finally holds the word with the lowest count (of those having the correct control unit identifier). The control unit identifier and destination data in this word are sent to a traffic programme store VPS which computes the required route and sends it via a store ZSP to the test and switch arrangement PEE which, using sampling device AE, checks whether the peripheral control units along this route are all free. If so, the control units are marked busy, a " despatch receptacle " signal is applied to the control unit initiating the request, the destination data is erased from the store AKS, and counter Z is incremented. If, on the other hand, at least one is busy, the scanning priority of the initiating control unit is raised to obtain preferential treatment in future, and the system proceeds to process other requests. A second embodiment (Fig. 3, not shown) for the case where each receptacle carries an identification marker, omits the count features and supplies the identification marker from the peripheral control unit via the lines NS 1 to a comparator for comparison with such a marker in each word of an associative store, destination data in the word giving equality being supplied to traffic programme store VPS together with the control unit identifier direct from the sampling device AE. A third embodiment (Fig. 2, not shown) for the case where each receptacle carries a destination marker, differs from the second embodiment in that it dispenses with the associative store and comparison, the destination being supplied to the traffic programme store VPS via the lines NS1 from the peripheral control unit. The central switching station in the conveyer system may have a higher scanning priority than the other stations.